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This is a continuation, of application Ser. No. 114,155 filed Jan. 22, 1980, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to an rpm governor for fuel-injected internal combustion engines, in particular a centrifugal governor of an injection pump for Diesel motor vehicle engines.
A centrifugal governor of this kind is already known (German Offenlegungsschrift No. 2 644 994) now U.S. Pat. No. 4,143,634, in which the initial stress of the idling spring is increased when the engine is cold by means of an idling correction apparatus equipped with a thermostat, in order to assure smooth running of the engine. The corrective final control element embodied as a thermostat is heated by a suitable apparatus attached to the electrical control circuit, and the duration of its switched-on time, which is necessary only during the warm-up phase of the engine, is limited by means of a temperature-dependent resistor introduced into the electrical circuit of the heating apparatus, this resistor preferably being embodied as a cold conductor (PTC resistor). This apparatus has the disadvantage that substantial forces must be brought to bear on a part of the thermostat because the idling spring, in order to fix the idling rpm, is already in contact, with a certain initial stress, with an adjustable support element. Furthermore, rapid adjustment of the idling rpm to changed engine loads is not possible in such an apparatus, because it functions relatively slowly and sluggishly.
OBJECT AND SUMMARY OF THE INVENTION
The rpm governor in accordance with the invention has the advantage over the prior art in that the adjustment force of the corrective final control element, which is dependent on at least one engine parameter, can be exerted at a point which is arbitrary and also favorable from the standpoint of available structural space on one of the movable elements of the governor or the injection pump used for controlling the idling position of the supply quantity adjustment member; thus there is great freedom as to the disposition of the idling correction apparatus. The adjustment force of the corrective final control element is superimposed on the governor forces and functions most favorably in the direction of the idling spring, counter to the adjustment force of the governor element; however, it is also possible for it to operate in the opposite direction. The associated control circuit may be embodied in simple fashion for open-loop control of the corrective final control element in the sense of maintaining the idling rpm or for closed-loop control of a constant idling rpm, and the adjustment force brought to bear by the corrective final control element is also introduced practically without loss directly into the governor and does not need to overcome any further initial stress or counteracting forces.
Advantageous further embodiments and improvements in the rpm governor are possible. Thus, in particularly advantageous fashion, an adjustment force can be generated which is independent of travel distance, when an electromagnet is used as the corrective final control element and has an adjustment force independent of the adjustment path and proportional solely relative to the energizing current of the control circuit. Thus, the armature of the electromagnet at least indirectly engages one of the elements of the governor which are moved in accordance with rpm during idling control. The invention extends, of course, also to variant embodiments in which the corrective final control element directly engages the supply quantity adjustment member of the injection pump.
Good and rapid response upon idling correction is attained and in an rpm governor known from the document cited above, having a guide lever supported on a rotary axis attached to the housing and guiding one end of the governor element, with appropriate reduction, very short adjustment paths are attained for the electromagnet. This also brings about a compact electromagnet which can be provided in simple fashion with an adjustment force independent of the adjustment path and proportional solely relative to the energizing current.
In an rpm governor, also known from the document cited above, having a force transmitting member subject to the restoring force of a main governor spring and arranged to contact a stop attached to the housing, the embodiment of the governor enables the installation of the idling correction apparatus on an already available governor without extensive conversion. By means of the deflection element, the adjustment path of the electromagnet needs to correspond only to the idling sleeve path of the governor member.
As a result, the control circuit can be adapted in simple fashion to the characteristics of the particular engine. As a result, a continuous closed-loop control of the idling rpm is possible, which enables a cyclical closed-loop control for maintaining a predetermined idling rpm. By means of the switches, a solely on-off switching is realizable both in the case of open-loop and closed-loop control, which results in an inexpensive circuit when relatively limited demands are placed on the quality of the open-loop or closed-loop control.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified cross-sectional view through the first exemplary embodiment; and
FIG. 2 is a fragmentary sectional view through a practical second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
On the camshaft 10 of a known injection pump for internal combustion engines, which is not shown in further detail, a flyweight carrier 11 of a centrifugal rpm governor embodied as an idling and final rpm governor, on which carrier 11 flyweights 12 are supported in a pivotable manner. These flyweights 12, with pressure arms 13, engage a governor sleeve 14 which serves as the control member and is thus adapted to transmit the sleeve stroke effected by the flyweights 12 to a bolt 16. The bolt 16 is articulated by means of a bearing tang 17 that is disposed on a guide lever 18 and which is pivotable on a bearing pin 21 secured in the governor housing 19 and thus, acting as a rotary axis, guides the governor sleeve 14 in its stroke movements.
By means of the bearing tang 17, a shift lever 22 is also articulatedly connected with the sleeve bolt 16 and furthermore pivotably connected to a lever-like setting member 25. The setting member 25 is secured on a lever shaft 26 supported as a pivot axis in the governor housing 19 which can be actuated by a service lever 27 shown in broken lines that is located outside the governor housing 19. The shift lever 22 is connected via a bearing point 28 with an intermediate lever 29 which serves as a control lever. The control lever is articulated at one end via an elastically yielding tongue 31 onto a control rod 32 which serves as the supply quantity adjustment member of the injection pump and is pivotably supported on the other end on a slidable bearing member 33.
By means of a setting screw 38, the slidable bearing member of the intermediate lever 29 is fixed in the axial direction of the governor sleeve 14 and can be changed by means of twisting the setting screw 38 for the purpose of making the basic setting of the full-load position of the control rod 32 which determines the full-load supply quantity, when, as is often desired by the engine manufacturer, the illustrated starting position and full-load position of the service lever 27 and thus of the setting member 25 is fixed by means of a full-load stop 41 that is attached to the housing and is not variable.
When the governor sleeve 14 has covered an idling sleeve path distance designated by the letter "a", the pressure bolt 16 then contacts an adapter spring capsule 42 which here serves as the stroke stop. The adapter spring capsule 42 is screwed into a force transmitting lever 43, which is pivotable about the bearing pin 21 and with its free end 43a is pressed by a main control spring 44 against a stop 45 that is attached to the housing. The initial stressing force of the main control spring 44 which functions as the final rpm control spring is determined by the position in which it is installed and can be readily set by means of a support 46 which comprises a threaded plug that is screwed into the governor housing 19. The threaded plug 46 is secured by means of a lock nut 47 in its set position and is disposed, like the stroke stop 42 and the setting screw 38 of the pivotal bearing 33 as well as an idling stop 48 embodied as a stop screw, within the governor housing 19 and is, like them, only accessible when a sealed locking cover 49 is removed.
Only a setting screw 51 which is adapted for the correction of the idling rpm of the engine is located outside the housing portion closed off by the cover 49 and thus is also accessible in the case of the sealed governor when the cover is removed. This is particularly advantageous, and is necessary for the purpose of adapting the idling rpm to the varying internal friction of different engines. A head 51a of the setting screw 51 located inside the governor housing 19 acts as an adjustable support for an end 52a of an idling spring member 52 embodied as a leaf spring, which is supported on the force transmitting lever 43 via a support angle bracket 53 which serves as a fixed support bearing or seat and with its terminal end 52b remote from the support 51a presses against a transverse bolt 54 that is disposed on the guide lever 18.
On the force transmitting lever 43, at the level of the fastening of the support angle bracket 53, there is secured an idling spring member 56 which is embodied as a leaf spring, which is provided with a connecting bolt 57. The connecting bolt 57 bears an adjusting nut 58, the distance d of which form a coupler part 18a on the guide lever 18 determines the portion b of the idling sleeve path a which determines the effective range of the additional idling spring member 56. In the illustrated full-load position of the setting member 25, the additional idling spring member 56 is pressed by a pressure screw secured on the setting member 25 out of its idling position indicated at 56' into the illustrated position, in which, during the course of the idling sleeve path a covered by the governor member 14 during starting, it is ineffective.
Engaging the coupler element 18a firmly connected to the guide lever 18 is a pressure pin 61 of a corrective final control element 62 which is secured on the locking cover 49, of an idling correction apparatus 63. The corrective final control element 62 here comprises an electromagnet embodied as a proportional or linear magnet, which is structured in a known manner such that it produces an adjustment force ΔP independent of adjustment path and solely proportional to the governor current I E of an electrical control circuit 64. An armature 65 of the electromagnet 62 is firmly connected to the pressure pin 51 and transfers the adjustment force ΔP indicated by an arrow in the pressure pin 61 onto the guide lever 18, which in this embodiment according to FIG. 1 acts as a force transmitting element for transmitting this adjustment force into the governor member 14.
The control circuit 64, shown in greatly simplified form and containing only the most essential components, is provided with a source 66 of electrical current and controls, primarily in accordance with temperature, the energizing current I E indicated by an arrow of a coil 67 of the electromagnet 62. Disposed in the electrical circuit of the control circuit 64 is a control element 68 which functions in accordance with a temperature T acting as the engine parameter, in series with the coil 67, which is embodied as a cold conductor (PTC resistor). This temperature-dependent resistor 68 may also be designed such that it is additionally heated up by the current flowing through it and thus acts as a control element which functions in accordance with time as well, which is indicated by an arrow t drawn in broken lines.
If in addition, consumers V, such as air-conditioning systems, compressors or the like are additionally driven by the engine, then the idling output of the engine may under some circumstances change greatly, and this changed output is taken into consideration in the control circuit 64 by means of a preliminary resistor 69 which is adapted to compensate for this additional load on the engine. The preliminary resistor 69 is introduced into the control circuit 64 parallel to the control element 68 and is switched on by a switch 71 when the consumer V is switched on. Parallel to the resistors 68 and 69 is a time-dependent resistor 72, introduced as a further control element functioning in accordance with time, which controls a partial current of the energizing current I E . This time-dependent resistor 72 may be omitted if a control effected only in accordance with temperature brings about a sufficiently precise maintenance of the idling rpm.
In place of the control element 68 which functions in accordance with temperature and arranged to control a continuously varying energizing current I E , the control circuit 64 can also contain a switch functioning in accordance with temperature, which then permits only an on-off control of the energizing current. This is possible when limited demands are placed on the precision of the idling rpm to be maintained and is then relatively inexpensive.
FIG. 2 shows the essential elements of a practical second embodiment which is essential to the invention; the elements, shown in simplified form, and which correspond to and function like those of FIG. 1 are given the same reference numerals, while components which are slightly modified are given a prime.
The force transmitting lever 43 pivotable about the bearing pin 21 and acting as the force transmitting element for the main control spring 44 contains, in a central longitudinal bore 75 of its stroke stop 42 which is embodied as an adaptation capsule, a pressure pin 76, which as the transmitting element for the adjustment force ΔP of an electromagnet 62' acting as the corrective final control element of an idling correction apparatus 63' is disposed in the extension of the longitudinal axis of the governor sleeve 14 between the sleeve bolt 16 of the governor member 14 and a pressure bolt 77 connected to the armature 65 of the electromagnet 62'.
The pressure pin 76 comprises two casings 79 and 81 guided one within the other in telescope fashion and containing a deflection spring 78 and thus serves at the same time as the spring-like, yielding deflection element. Such a deflection element being disposed in the connection between the electromagnet 62' and the governor sleeve 14 has the advantage that the stroke of the armature 65 of the electromagnet 62' needs to be only as large as the idling sleeve path a of the governor sleeve 14. The governing stroke of the governor sleeve 14 subsequent to the idling sleeve path, and thus the corresponding path of the force transmitting lever 43 covered counter to the force of the main control spring 44, is then performed by the deflection element 76. The structural length of the entire governor is accordingly not unduly increased, and the adjustment force ΔP which is preferably independent of the adjustment path and fixed only by the energizing current I E of a control circuit 64' can be particularly favorably maintained for a relatively short stroke given a correspondingly simple embodiment of the components of the electromagnet 62'.
The control circuit 64' supplied by the electrical current source 66, in the exemplary embodiment shown in FIG. 2, serves to effect not open-loop but closed-loop control of the energizing current I E , because here the actual rpm n detected by an rpm transducer 82 is fed, as the sole engine parameter, into a comparison circuit 83 of the control circuit 64' and after comparison with a desired rpm value n L it is converted to the energizing current I E which determines the adjustment force ΔP of the electromagnet 62'.
The electromagnet 62' can also be operated cyclically, and when there are limited demands for constancy in the idling rpm n L then instead of the comparison circuit 83 a switch 84, shown in dot-dash lines, which is actuated in accordance with rpm can be used. Here it is particularly advantageous if a preset energizing current I E is controlled by the current source 66 and the switch 84, upon exceeding an upper desired rpm value, opens the electrical circuit and when a lower desired rpm value is not attained closes this electrical circuit again. In order to cancel out any current surges which occur, a freewheeling diode 85 is introduced into the circuit.
The switch 84 can also be operated in accordance with the exceeding, or non-attainment, of a temperature threshold T, as indicated in brackets, instead of in accordance with an rpm-dependent signal. Then, however, only on-off control occurs and additional consumers would have to be switched in by means of the parallel disposition of a preliminary resistor which corresponds to the preliminary resistor 69 of FIG. 1.
The circuits given in FIGS. 1 and 2 are not restricted to these examples, but rather can be interchanged or used for triggering corrective final control elements which engage other points of the governor.
The mode of operation of the governor embodied in accordance with the invention and shown in FIGS. 1 and 2 will now be briefly described in order to supplement the foregoing specification.
All the governor elements in FIG. 1 are shown in the position of rest when the setting member 25 is pivoted into the full-load position for starting; in this position of rest, the service lever 27 is in contact with the full-load stop 41. The control rod 32 is in the maximum position which determines the starting quantity, this position being indicated in the drawing by "max". Upon starting of the engine, the flyweights 12 swing outward and the governor sleeve 14 performs its idling sleeve stroke a and thus draws the control rod 32, via the control lever 29, into its full-load position V. Now when, in order to govern the idling rpm, the setting member 25 is drawn back into its idling position (not shown), then the setting member pivots clockwise about the lever shaft 26 and contacts the idling stop 48. At this time, the additional idling spring member 56 is in its position marked in dot-dash lines at 56' which influences the idling control operation and when the idling rpm is maintained the control rod 32 assumes a position L. When the engine is cold, however, this normal position is not sufficient to supply the engine with the supply quantity which corresponds to idling output. Thus, if the operating temperature T is below a certain temperature threshold, then the control circuit 64 has supplied a corresponding energizing current I E to the coil 67 of the electromagnet 62, and the armature 65 exerts an additional adjustment force ΔP, increasing the idling supply quantity, on the guide lever 18 via the coupler part 18a. This guide lever 18 transmits this additional force onto the governor sleeve 14, which at the same idling rpm causes a correspondingly predetermined displacement of the control rod 32 from its normal idling position L toward the full-load position V. When the temperature of the engine is increasing or after the passage of a predetermined period of time, the cold conductor 68 and the time-dependent resistor 72 reduce the energizing current I E and the adjustment force ΔP drops accordingly, until it has been entirely eliminated. The control rod 32 is then again in its idling position L which is fixed for normal operation.
The same function is also performed in FIG. 2 by the electromagnet 62'; however, its adjustment force ΔP is directly transmitted onto the governor sleeve 14. However, as has already been described, if instead of an energizing current I E controlled in accordance with rpm an on-off switching is performed by the switch 84, then in accordance with the switching on or off of the energizing current I E an adjustment force ΔP predetermined by the electrical current source 66 is switched briefly on or off. As a result of this additional force, which varies abruptly, the engine shifts between a lower and an upper idling rpm. If this switching is embodied as sufficiently rapid and with narrow tolerances, then this causes a cyclical impact on the governor sleeve 14 and in practical terms brings about a constant position of the control rod adapted to the particular operational status of the engine prevailing at that time.
The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other embodiments and variants thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
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An rpm governor for fuel-injected internal combustion engines is proposed, in particular a centrifugal rpm governor of an injection pump for Diesel motor vehicles, in which the idling rpm is also held constant when the engine is cold or loaded by additional consumers, in order to assure smooth running of the engine and the most favorable values for fuel consumption and exhaust emissions. The governor contains an idling correction apparatus with an electromagnet, which transmits an additional adjustment force, which is preferably independent of travel distance and variable only by the energizing current of a control circuit, onto the governor member via a transmission element. By means of varying or switching on or off of the adjustment force, the idling rpm which is fixed by the initial stress of an idling spring for the warm and unloaded engine is also held constant under changing operational conditions.
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BACKGROUND OF THE INVENTION
The present invention relates to an evaporator assembly of the type disclosed in U.S. Pat. No. 3,766,976-Gelbard et al and 4,211,090-Gelbard et al, both assigned to General Electric Company, the assignee of the present invention.
The evaporator assembly in this type of refrigerator is in fact included in the partition which divides the fresh food compartment from the freezer compartment. Since the partition incorporating the evaporator is located totally within the refrigerator cabinet, it is essential that the amount of space it occupies be kept to a minimum. The temperature of the compartments is maintained by circulating air from the compartment across the evaporator coils. Due to the limited amount of space air flow initially contacts the leading portion of the evaporator and then flows downstream therethrough. When this happens frost builds up on the leading edge of the evaporator and accordingly restricts flow through the rest of the evaporator.
By the present invention the evaporator is so constructed that substantially all of the air flowing through the partition comes in direct contact with substantially all of the evaporator surface area. This requires that the evaporator assembly be designed and the parts arranged so that maximum air flow and efficiencies are built into an assembly occupying a minimum amount of space in the refrigerator cabinet.
In accordance with the present invention, a construction is provided which ensures an even distribution of frost throughout the evaporator surfaces, and which accomplishes this result in a simpler and more effective manner and with advantages not present in the prior art type arrangements described above.
Accordingly, it is an object of this invention to provide in a refrigerator of this type an improved air circulation and frost deposition arrangement which materially reduces interference with the circulation of air.
SUMMARY OF THE INVENTION
By the present invention there is provided a refrigerator cabinet including a fresh food storage compartment to be maintained at a temperature above freezing and a freezer compartment to be maintained at a temperature below freezing. An evaporator partition divides the cabinet into the compartments. The partition includes a lower wall portion defining the upper wall of the fresh food compartment, and a removable upper wall portion defining the lower wall of the freezer compartment. The partition includes an evaporator chamber defined between the lower and upper wall portions. Mounted in the evaporator chamber is an evaporator including a tubular member bent to form at least two interconnected longitudinally arranged helically coiled portions. The longitudinal axis of the rear coil being above the longitudinal axis of the forward coil. The rear coils are formed to provide a centrally located area between coiled end portions. Also formed in the partition are air passageways for directing a stream of air to be cooled through the evaporator chamber. The air passageways include inlets in the upper and lower wall portions for drawing air from the fresh food and freezer compartments and circulating through the evaporator chamber. An outlet in the upper wall portion directs air into passageway communicating with the freezer fresh food compartments. Located in the outlet opening is a fan whose drive motor is arranged in the centrally located area between the coiled end portions of the rear coil. The fan circulates air from the inlets to the passageways and through the evaporator to the outlet.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a refrigerator incorporating the present invention;
FIG. 2 is an enlarged vertical side elevational view through a portion of the refrigerator showing the partition embodying the present invention; and
FIG. 3 is a plan view of the partition with parts broken away to show further details.
DESCRIPTION OF THE PREFERRED EMBODIMENT
While the present invention is applicable to any refrigerator including one or more storage compartments and an evaporator for cooling the compartment disposed in an evaporator chamber, it will be particularly described with reference to a refrigerator such as that disclosed in the above-mentioned Gelbard patents to which reference is made for detailed description of refrigerator components.
With reference to FIG. 1, the illustrated refrigerator comprises a cabinet 10 which includes an upper below-freezing or freezer compartment 11 and a lower above-freezing or fresh food storage compartment 12. The compartments 11 and 12 are separated by an insulated partition generally indicated by the numeral 14. The refrigerant system includes an evaporator 15 located in the partition 14, a condenser 16 and compressor 17 interconnected in series flow arrangement. Also as is customary in household refrigerator systems there is provided an accumulator 21 employed traditionally for charge management purposes.
The partition 14 (FIG. 2) includes upper removably arranged wall 18 and a lower wall 19 defining an evaporator chamber 20. It should be noted that the upper wall 18 defines the lower wall of the freezer compartment 11 while the lower wall 19 defines the upper wall of the fresh food compartment 12. Mounted in the partition 14 is a housing 22 which forms the evaporator chamber 20 in which the evaporator 15 is arranged. The housing includes a base wall portion 24 spaced and insulated from the lower wall 19 a top wall portion 26, and a rear wall 28 spaced from the rear wall 30 of the refrigerator cabinet 10. The walls 24 and 26 at the forward portion of the chamber 20 are spaced to include an inlet opening 32.
For the purpose of maintaining these two compartments 11 and 12 at the desired operating temperatures by means of the evaporator 15 contained within the evaporator chamber 20, a fan 34 is provided for withdrawing air from the two storage compartments. The fan 34 is supported on the upper wall 18 with its blade mounted in an opening 35. By this arrangement the fan may be serviced by lifting and removing the wall 18 from the partition assembly. Air from compartment 11 is withdrawn through an inlet 36 in wall 18. The opening 36 is arranged at the forward end of a passage 38 in the partition leading to the opening 32 of evaporator chamber 20. Air cooled by passing through the evaporator 15 is returned to the freezer compartment through opening 35 to a passage 40. The passage 40 is formed by a shroud member 42 which serves to distribute the air from the opening 35 at the outlet end of the evaporator chamber 20. Air from storage compartment 12 is with- drawn through an inlet 44 in lower wall 19. The opening 44 is arranged at the forward end of a passage 45 leading to opening 32 of evaporator chamber 20. Air cooled by passing through the evaporator is returned to the storage compartment 12 through passage 46. The passage as shown in FIG. 2 is defined by wall 28 at the rear of the partition 14 and rear wall 30 of the refrigerator cabinet. While the recirculating air streams of the compartments 11 and 12 were described separately it should be noted that the air from both compartments is mixed as they enter the chamber 20 through inlet 32. In the present embodiment approximately 90% of this mixed cooled air is returned to the freezer compartment 11 with 10% returning to the fresh food compartment 12.
In the illustrated embodiment of the invention the refrigerator system evaporator 15 actually comprises two helically coiled members 50 and 52. The axis of the coil members extend parallel to one another and transversely of the chamber 20. The coil 52 is arranged to the rear of or downstream of coil 50. The portions 50 and 52 are connected in series through a section of evaporator tubing which is partially straightened and deformed to provide a connection between the two members 50, 52 at one side of the evaporator 15. The rear coil 52, as best shown in FIG. 3, contains two transversely separated end portions 52a and 52b creating a centrally located space or area 54. The fan 34 which as mentioned above is mounted on the upper wall 18 has its motor positioned partially below the coil 52 between the end portions 52a and 52b and generally in the area 54. The refrigeration system accumulator 21 is locatd below the coil 52 and generally in the area 54 between the end portions 52a and 52b of coil 52.
The extended heat transfer surface for transferring heat from a stream of air passed over the evaporator 15 to the refrigerant flowing through the tubular evaporator 15 comprises a plurality of pin fins 49 (FIG. 2) extending generally radially inwardly from the coils 50, 52 so that all of the fin structure is within the area or volume encompassed by the coils 50, 52.
In order to maintain the refrigerator at a desirable level of operating efficienty, it is necessary from time to time to initiate a defrost operation to remove the frost from the evaporator surfaces. This may be accomplished in a number of ways, for example, by providing an electric heating element which is energized at intervals to melt the frost. A suitable electric heating element 60 for this purpose is shown (FIGS. 2 and 3) extending transversely of the chamber 20. The heater 60 is positioned adjacent the lower wall 24 of chamber 20 at a location between the lower portion coils 50 and 52. This position of the heater as shown in FIG. 2 exposes a substantial area of both coils 50, 52 to the radiant energy of the heater during the defrost operation.
It should be noted that the accumulator 21 due to its arrangement in the suction line is generally the coldest component in the system and accordingly frost tends to build up on it in heavier concentrates relative to the warmer components. The accumulator 21 because of its position relative to the heater as shown in FIG. 2 is exposed to the radiant energy of the heater during the defrost operation.
With reference to FIGS. 2 and 3 of the drawing, it will be seen that air drawn into the front or inlet end 32 of the evaporator chamber 20 by operation of the fan 34 flows laterally or transversely between the evaporator coils, that is, through passages 56 (FIG. 2) between the coil passages or portions 50, 52. Since the pin fins 49 are all contained within the helix, the air initially contacts the tubular member where moisture begins to collect in the form of frost. The air passing through the passages 56 then comes into heat exchange contact with the internal fin structure extending part way into each of these passages from the adjacent coil and then more or less directly impinges on the fins extending radially inwardly or forwardly from the rear portion of the coil.
By the present invention means are provided for increasing the frost tolerance of the evaporator by insuring that frost build-up is evenly distributed on the evaporator surfaces. In order to accomplish this objective the evaporator 15 of the illustrated embodiment has been configured so that substantially all of the air flowing through the chamber 20 contacts both of the coil members 50 and 52. In this end as shown in FIG. 2, the coil 52 is raised relative to coil 50 so that a portion of coil 52 is effectively located in the path of air flowing through inlet 32 of chamber 20. Since the front coil 50 contains more surface, it in fact does the primary cooling and the sensible heat is also first removed by coil 50 with the remaining sensible heat removed by coil 52. The raised position of the rear coil 52 by its placement in the air stream creates an evaporator having a greater frost tolerance. By exposing a greater portion of the total evaporator surface to the circulating air stream a more equal distribution of frost is achieved. By the present configuration in the event frost does initially build up on the front coil 50 thereby decreasing air flow therethrough a greater amount of air will then flow past it and eventually most of the air will then flow through on the rear coil 52. This allows for the even distribution of frost and lessening the chances of frost build-up from blocking air flow through the evaporator. To enhance the distribution of air across the surface area of the evaporator additional inlets 66 (FIG. 3) communicating directly into the chamber 20 may be provided adjacent the side walls of the refrigerator cabinet so that a portion of the air returning from compartment 11 is directed inwardly.
It should be apparent to those skilled in the art that the embodiment described heretofore is considered to be the presently preferred form of this invention. In accordance with the Patent Statues, changes may be made in the disclosed apparatus and the manner in which it is used without actually departing from the true spirit and scope of this invention.
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A compact evaporator unit for a household refrigerator including a partition dividing the refrigerator into two separate compartments. The partition is formed with an evaporator compartment in which the evaporator is positioned. The evaporator comprises a tubular member having an extended heat exchange surface in the form of a pair of longitudinally extending helically coiled portions. The coiled portions are arranged parallel with the rear coil being elevated relative to the front coil. The rear coil is extended to form end coils which provide a central area between the end coils to accommodate a fan employed for moving air through the evaporator compartment. The rear coil being raised so that the flow of air passing through the evaporator compartment will impact on both coils to thereby increase the frost tolerance of the evaporator.
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FIELD OF THE INVENTION
[0001] The present invention relates to a shell body light sculpture, in particular, a shell body light sculpture provided with decorative lights on and/or in it's shell.
BACKGROUND OF THE INVENTION
[0002] There are two kinds of light sculptures available in the present market. The first one is called Light Wire Sculpture or called Decorative Silhouette. It's made with metal or plastic wire or strip, wound and welded together to make a dummy animal or human being figure, on which a number of decorative lights are attached with ties or clips; the second one is called Blow-Mold Light Sculpture. It's to employ the blow-molding technique to make an integral dummy shell body in which 1 to 5 halogen bulbs, or illuminating lamps, or C7, C9 type lamps are fixed to illuminate the plastic shell. It can be noted that there are a number of defects existing in the above-mentioned light sculptures.
[0003] With regard to the first kind of light sculpture in the prior art, on the one hand, as it's made with metal or plastic wire or strip, the integral body only presents a skeletal frame work, far from achieving the realistic effects of appearance true to life; on the other hand, since the power cords and decorative lights are all exposed, the appearance is in a mess, the integral simulating effect is poor, the decorative effect is poor of course. Further more, the decorative lights on said light wire sculptures in prior art are all exposed, the bulbs are always broken and the lights would fall off during the transportation and installation. This would cause disconnection of power source or short circuit, resulting in totally or partially ceasing of illuminating.
[0004] With regard to the second kind of light sculpture in the prior art, first, it employs a blow-molded shell body, but it only employs with 1 to 5 common illuminating lamps or holgen bulbs all inside the shell body. This makes only a few portions, not all of the shell body illuminated, so the whole image cannot be seen at night. Second, as the shell body in the prior art is blow-molded as the whole piece, it's packing volume is comparatively quite large, causing higher cost and greater inconvenience in transportation and storage.
SUMMARY OF THE INVENTION
[0005] The main object of the present invention is to provide a shell body light sculpture, which can present static and realistic decorative effects by using shell body, fixed with many decorative lights. The lights or lighting rays shines through or out on the shell body to illuminated the whole shell body sculpture of various figures, such as animals, human being figures and articles etc.
[0006] The further object of the present invention is to provide a shell body light sculpture whose shell body is detachable and/or foldable. The packing volume is effectively reduced by means of using separable joints between various parts of the shell body, so that the transportation cost is greatly reduced and storage is much more convenient.
[0007] To achieve the above purposes, the present shell body light sculpture comprises a shell body of optional mimic figures and a plurality of series and/or paralleled decorative lights, wherein a plurality of decorative lights can be detachably mounted on the shell body.
[0008] A shell body light sculpture according to the present invention, wherein the shell body is provided with a number of hole portions for mounting the decorative lights; and a number of light buttons fitting the hole portions for fixing the decorative lights.
[0009] A shell body light sculpture according to the present invention, wherein the light button is provided with a wall portion to be fitted with the hole portion, used for gripping a lamp holder of the decorative light; and a shoulder portion projecting outward from the wall portion, used for lapping the shell body.
[0010] A shell body light sculpture according to the present invention, wherein the light button is provided with a slit extending across the shoulder portion and the wall portion.
[0011] A shell body light sculpture according to the present invention, wherein the slit is a conical slit widening gradually from the shoulder portion to the wall portion.
[0012] A shell body light sculpture according to the present invention, wherein the inner side of the wall portion is provided with hole portions mated with the prefabricated protrusions on the lamp holder of the decorative light.
[0013] A shell body light sculpture according to the present invention, wherein a base portion is provided on the inner side of the wall portion, used for fixing the lamp holder of the decorative light.
[0014] A shell body light sculpture according to the present invention, wherein protrusions are provided on the outer side of the wall portion with a space of constant pitch from the shoulder portion, used for fastening with the shell body.
[0015] A shell body light sculpture according to the present invention, wherein the light buttons are designed to be integrally shaped hole portions and are projecting from the inner side of the shell body.
[0016] A shell body light sculpture according to the present invention, wherein the shell body is provided with depression portions at the hole portion, for accessing the inlay stripes.
[0017] A shell body light sculpture according to the present invention, wherein the shell body is to be shaped through assemblage of detachable coupling parts.
[0018] A shell body light sculpture according to the present invention, wherein the coupling parts are disposed along the image body.
[0019] A shell body light sculpture according to the present invention, wherein the coupling parts of the shell body comprises a hole portion provided in one lateral edge of the shell body and a projecting pin provided correspondingly on the other lateral edge of the shell body, its capping head piercing through the hole portion.
[0020] A shell body light sculpture according to the present invention, wherein the coupling parts of the shell body comprise two hole portions provided correspondingly with each other in each lateral edge of the shell body; and one through pin having a cap-like end, piecing through the two hole portions.
[0021] A shell body light sculpture according to the present invention, wherein the coupling parts of the shell body comprise two hole portions provided in parallel with each other in each lateral edge of the shell body and one jam sheet having two spaced apart projecting pins, their capping heads piercing respectively through the two hole portions.
[0022] A shell body light sculpture according to the present invention, wherein the coupling parts of the shell body are of a mortise and tenon joint structure or a zipper socket joint structure.
[0023] A shell body light sculpture according to the present invention, wherein the coupling parts of the shell body comprise a groove provided on lateral edge of the shell body and a ledged portion provided correspondingly on the other lateral edge of the shell body mated with the groove.
[0024] A shell body light sculpture according to the present invention, wherein the coupling parts of the shell body comprise an inward curled knot curled inwardly from one lateral edge of the shell body and an outward curled knot curled outwardly from the other lateral edge of the shell body to be mated with the inward curled knot.
[0025] A shell body light sculpture according to the present invention, wherein the coupling parts of the shell body are of a hinge joint structure and/or a screw joint structure or a plastic hasp joint structure.
[0026] A shell body light sculpture according to the present invention, wherein the coupling parts of the shell body comprise at least two hole portions staggered with each other on each of the lateral edges of the shell body, and a through pin piercing through the at least two hole portions from outside of the shell body.
[0027] A shell body light sculpture according to the present invention, wherein surface of the shell body is provided with an ornamental layer.
[0028] According to one aspect of the present invention, as it adopts the process of fixing the decorative lighting strings from the inside of the shell body or intermediately of it, the decorative lights and its power cords are situated within said shell body or intermediately of it, so the problem of the lights falling off during transportation and use is properly resolved, and also the service life and reuse rate is increased greatly. According to the other one aspect of the present invention, as it employs a detachable and foldable shell body, the packing volume of the product is considerably reduced, so the transportation cost is reduced and storage space is greatly saved.
[0029] According to another aspect of the present invention, as said shell body is made up of several molded pieces (Not only whole big shell body), the shell body can be molded with great details, so said Shell Body Light Sculpture of the present invention can most vividly present the image it represents no matter whether it is illuminated at night or not at the day time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Now the present invention will be obvious by description combined with the following drawings and the preferred embodiments.
[0031] [0031]FIG. 1 is the integrally static schematic view of one of a shell body light sculptures of the present invention, as an image of deer assembled with a number of decorative lights on the shell body;
[0032] [0032]FIG. 2 is the partial schematic view of the embodiment shown in FIG. 1, showing the dynamic decorative lighting effects of the present invention while it's illuminated;
[0033] [0033]FIG. 3 is the schematic view of the first embodiment of the shell body of the present invention assembled with the decorative lights, showing how the light button hold the decorative lights;
[0034] [0034]FIG. 4A is the schematic view showing the assemblage of decorative light with said light button of the present invention;
[0035] [0035]FIG. 4B is the sectional view adopted along line D-D in FIG. 4A;
[0036] [0036]FIG. 5 is the perspective view of the decorative light bulb inserted in the lamp holder with depression portion for fixing with the said hole in said shell body of the present invention;
[0037] [0037]FIG. 6A is the perspective view of the light button of the present invention provided in the shell body, showing the Light Button fixed in the shell body by means of said shoulder portion and said protrusions on the wall portion of said light button;
[0038] [0038]FIG. 6B is the bottom view of the light button of the present invention shown in FIG. 6A, showing the base portion provided at the bottom for holding the lamp holder of said decorative light;
[0039] [0039]FIG. 7 is the schematic view of the second embodiment of the shell body of the present invention, assembled with the decorative lights, showing said light button anchoring said decorative light and said hole portion to be mated with the protrusions on the lamp holder of said decorative light;
[0040] [0040]FIG. 8 is the schematic view of the third embodiment of the shell body of the present invention for disposing the decorative light;
[0041] [0041]FIG. 9 is the schematic view of the fourth embodiment of the shell body of the present invention assembled with said decorative lights, showing the decorative lights fixed on said shell body by means of inlay stripes;
[0042] [0042]FIG. 10 is the schematic view of the first embodiment of the connecting of the coupling parts of the shell body as a deer image shown in FIG. 1, wherein the projecting pin provided on one segment of said shell body mated with the hole portions of the other segment;
[0043] [0043]FIG. 11 is the schematic view of the second embodiment of the connecting of the coupling parts of the shell body as the deer image shown in FIG. 1, wherein through pin pierces through the hole portions provided in both shell body segments;
[0044] [0044]FIG. 12 is the schematic view of the third embodiment of the connecting of the coupling parts of the shell body as the deer image show in FIG. 1, wherein a jam sheet having two spaced apart projecting pins, the pins pierce respectively through the two hole portions in the shell body;
[0045] [0045]FIG. 13 is the schematic view of the fourth embodiment of the connecting of the coupling parts of the shell body as the deer image shown in FIG. 1, wherein said coupling parts have mortise and tenon joint structure;
[0046] [0046]FIG. 14 is the schematic view of the fifth embodiment of the connecting of the coupling parts of the shell body as the deer image shown in FIG. 1, wherein the coupling parts are of zipper socket joint structure;
[0047] [0047]FIG. 15A is the schematic view of the sixth embodiment of the connecting of the coupling parts of the shell body as the deer image shown in FIG. 1, wherein the through pin pierces through the staggered hole portions in the two shell body segments;
[0048] [0048]FIG. 15B is the sectional view of the embodiment shown in FIG. 15A adopted along line E-E;
[0049] [0049]FIG. 16 is the schematic view of the seventh embodiment of the connecting of the coupling parts of the shell body as the deer image shown in FIG. 1, wherein the outward curled knot provided on one shell body segment is mated with the inward curled knot provided in the other segment;
[0050] [0050]FIG. 17 is the schematic view of the eighth embodiment of the connecting of the coupling parts of the shell body as the deer image shown in FIG. 1, wherein the ledge portion provided on one shell body segment is mated with the groove provided in the other segment and the surface of the shell body is covered with an ornamental layer;
[0051] [0051]FIG. 18 is the schematic view of the ninth embodiment of the connecting of the coupling parts of the shell body as the deer imaged shown in FIG. 1, wherein the coupling parts are of a hinge structure;
[0052] [0052]FIG. 19 is the schematic view of the tenth embodiment of the connecting of the coupling parts of the shell body as the deer image shown in FIG. 1, wherein the coupling parts comprises the plastic hasp;
[0053] [0053]FIG. 20 is the schematic view of the eleventh embodiment of the connecting of the coupling parts of the shell body as the deer imaged shown in FIG. 1, wherein the coupling parts are connected with pin piercing through the shell body.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] The following is further detailed descriptions for the present invention.
[0055] First, let's take one of the deer images as an example to describe the constructions of various parts of the shell body light sculpture 10 of the present invention. As shown in FIG. 1, for mounting said decorative lights, the convenient and lower cost transportation and storage, firstly, the integral figure is divided along its longitudinal axis into two separate divisions in which the shell body of the Shell Body Light Sculpture of the present invention is provided with detachable or foldable structure. Accordingly, it's necessary to provide coupling parts in the shell body, for example, at the location A or B. At the same time, a number of decorative lights 14 is detachably fixed on and/or in the shell body 12 . While the lights lit up they produce dynamic light effects at the shell boy of the present invention, such as shown in the schematic view of the deer head in FIG. 2.
[0056] The construction of the mounting of the decorative light 14 on and/or in the shell body 12 is shown in the first embodiment of the present invention shown in FIG. 3. In said first embodiment, a number of hole portions 120 are firstly provided in the shell body 12 , and the decorative lights 14 are mounted on and/or in the shell body 12 by means of Light Buttons. Light Button 20 fitted in the hole portion 120 . FIG. 4A is a schematic view showing the assemblage of the decorative light 14 of the present invention with the Light Button 20 . More detailed perspective view of the decorative light 14 is shown in FIG. 5. The lamp holder 16 is used in the present invention to fix the decorative light 14 , performing the function of protecting the decorative light 14 , and the power cords 18 are used to connect other decorative lights (not shown). FIGS. 6 A- 6 B show the detailed construction of the Light Button 20 of the present invention, it comprises integrally: a wall portion 204 mated with the hole portion 120 , used for gripping the lamp holder 16 ; a shoulder portion 202 projecting outward from the wall portion 204 , for lapping the shell body 12 ; a slit 208 extending across the shoulder portion 202 and the wall portion 204 used for inserting in said power cords 18 from this slit 208 to facilitate the mounting of said decorative light 14 . Further more, to fasten the decorative light 14 tighter, the Light Button 20 also comprises a base portion 210 provided on the inner side of the wall portion 204 for fixing the shoulder portion of 160 of the lamp holder 16 , as shown in FIG. 4B. As the Light Button 20 tightly grips the lamp holder 16 , the slit 208 is preferably to be made in the form of a conical slit, widening gradually from the shoulder portion 202 to the wall portion 204 . Besides, on the outer side of the wall portion 204 , protrusions 206 are provided with space of a constant pitch from the shoulder portion 202 , used for fastening with the shell body 12 . Obviously, the decorative light 14 can be fixed tight enough, according to the practical requirement, it could be either higher than the outer surface of the shell body 12 or lower than the outer surface of the shell body 12 by adjusting the height of the Light Button 20 .
[0057] The construction of the decorative light 14 mounted on and/or in the shell body 12 can be modified, if, as shown in FIG. 7, a plurality of hole portions 209 are provided in the wall portion of the Light Button 20 to be mated with the protrusions 161 prefabricated on the lamp holder 16 , so the decorative lights are better fixed. The construction of the decorative light 14 assembled on and/or in the shell body 12 can be further simplified, if, as shown in FIG. 8, the Light Button 20 for accommodating the decorative light 14 is designed to be integral with the shell body 12 and projecting inwardly from the shell body 12 . As shown in FIG. 9, it's also possible to provide a depression portion 122 in the shell body 12 near the hole portion and inlay stripes 212 to be also provided mated with the depression portions 122 to fix the decorative lights 14 of the present invention by embedding the inlay stripes 212 into the depression portions 122 .
[0058] It is more preferable that a foldable shell body structure is provided and used in the present invention. FIG. 10 is a schematic view of the first embodiment of the coupling parts 30 of the shell body of the present invention. The coupling parts 30 are substantially perpendicular with the shell body and comprise: a hole portion 302 provided on one lateral edge of the shell body 12 ; and a projecting pin 304 provided correspondingly on the other lateral edge of the shell body. Its capping head 306 pierces through the hole portion 302 . Thus, the projecting pin 304 can fasten the two shell body segments 12 together.
[0059] [0059]FIG. 11 is a schematic view of the second embodiment of connecting the coupling parts 30 of the shell body of the present invention, wherein the coupling parts 30 comprises: two hole portions 310 provided correspondingly with each other on each lateral edge of the shell body 12 ; and on through pin 312 having a cap-like end 314 piercing through the two hole portions 310 to fix the whole shell body 12 .
[0060] [0060]FIG. 12 is a schematic view of the third embodiment of connecting the coupling parts 30 of the shell body of the present invention, wherein the coupling parts 30 is first provided with an depression portion 320 and comprise: two hole portions 322 , provided parallel with each other on each lateral edge of the shell body 12 ; and one jam sheet 324 having two spaced apart projecting pins 326 , their capping heads 328 piercing respectively through the two hole portions 322 . In this way, the jam sheet 324 is disposed in the depression portion 320 , being substantially flush with the surface of the shell body 12 .
[0061] [0061]FIG. 13 is a schematic view of the fourth embodiment of connecting the coupling the portions 30 of the shell body of the present invention, wherein each shell body segment 12 is respectively provided with: a tenon 330 ; and a mortise 332 , so to form a mortise and tenon joint structure.
[0062] [0062]FIG. 14 is the schematic view of the fifth embodiment of connecting the coupling the portions 30 of the shell body of the present invention, wherein the coupling parts 30 comprises: a number of female tooth grains 340 provided on one side of the shell body segments 12 ; and a number of male tooth grains 342 provided on the other shell body segment 12 , so as to for a zipper socket joint structure.
[0063] [0063]FIG. 15A is a schematic view of the sixth embodiment of connecting the coupling the portions 30 of the shell body of the present invention, wherein the coupling parts 30 comprises: two hole portions 350 and 352 , provided aligned and staggered with each other on each lateral edge of the shell body 12 ; and a through pin 354 , piercing through the two hole portions 350 and 352 from outside of the shell body 12 , so as to form a folding cylinder joint structure, as shown in the sectional view of FIG. 15B.
[0064] [0064]FIG. 16 is a schematic view of the seventh embodiment of connecting the coupling parts 30 of the shell body of the present invention, wherein the coupling parts 30 comprise: an inward curled knot 360 , curled inwardly from one lateral edge of the shell body 12 ; and an outward curled knot 362 , curled outwardly from the other lateral edge of the shell body 12 mated with the inward curled knot 360 . Of course, the shell body has fairly good resilience.
[0065] [0065]FIG. 17 is a schematic view of the eighth embodiment of connecting the coupling parts 30 of the shell body of the present invention, wherein the coupling parts 30 comprises: a groove 370 , provided on one lateral edge of said shell body 12 ; and a ledge portion 372 provided correspondingly on the other lateral edge of said shell body mated with said groove.
[0066] [0066]FIG. 18 is a schematic view of the ninth embodiment of connecting the coupling parts 30 of the shell body of the present invention, wherein the coupling parts 30 employs a hinge joint 380 , that is, the two limb flaps of the hinge joint are separately provided on each of the two shell body segments, so that the shell body of present invention in foldable.
[0067] [0067]FIG. 19 is a schematic view of the tenth embodiment the connecting the coupling parts 30 of the shell body of the present invention, wherein the coupling parts 30 provide a plastic hasp 386 on the overlapping portions of the two shell body segments 12 to for a simply constructed joint.
[0068] [0068]FIG. 20 is a schematic view of the eleventh embodiment of the connecting the coupling parts 30 of the shell body of the present invention, wherein the coupling parts 30 comprise a through pin 390 , piercing directly through the upper and lower sides of the shell body 12 .
[0069] Apparently, in order to enhance the ornamental effect, the shell body of the present invention can be covered with various ornamental layers, such the scored layer 124 shown in FIG. 17 and the coating layer or paint layer 126 shown in FIG. 19.
[0070] While the present invention has been described with reference to the above-mentioned preferred embodiments, it should be understood that various changes and modifications could be made within the protection scope of the appended claims.
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The present invention relates to a mimic shaped Shell Body Light Sculpture. The main constructional feature is to mount decorative lights on and/or in the shell body of the mimic figure in the purpose of enhancing fidelity of the mimic figure decorative effects, so as to prolong the service life of the product and to make the product more convenient for use. The advantages of the present invention include: the mimic figure presenting integral sparkling starlight effects while it's lighted at night, and still presenting most vivid and life-like images while is not lighted at the daytime; resolving the problems of bulb breaking, falling off, power cords messing up, short circuits and so on, at the same time increasing the reuse rate, the transportation and installation, convenience, while the cost being reduced.
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FIELD OF THE INVENTION
[0001] The present invention generally relates to cluster file systems in which a cluster of servers directs access to one or more storage devices. In particular, the present invention pertains to a method for maintaining state integrity during failure, failover, fail-back, and load balancing of servers in the cluster file system.
BACKGROUND OF THE INVENTION
[0002] The quest to make Network Attached Storage (NAS) scaleable has lead to architectures that depart from a traditional direct-attached storage (DAS) model. The DAS architecture comprises several storage devices attached to a single computer. In emerging NAS architectures (further referenced herein as a NAS clustered architecture) a cluster of computers comprises a NAS gateway. The NAS gateway shares the work of a traditional single-node NAS server. Storage devices are shared among the members of the cluster via a Storage Area Network (SAN).
[0003] The NAS clustered architecture is preferred to the traditional single-server architecture for various reasons. The NAS clustered architecture is highly scaleable in two dimensions: the quantity of storage devices that can be used and the number of computing servers performing file system services. Further, the NAS clustered architecture exhibits enhanced fault tolerance that makes it the preferred architecture of future NAS devices.
[0004] Although this technology has proven to be useful, it would be desirable to present additional improvements. Network-file access protocols such as, for example, the network file system (NFS) protocols that were traditionally embedded in NAS devices were not designed with such clustered architectures in mind. Consequently, the fault-tolerant file and record locking features supported by those protocols do not work well in the NAS clustered architecture.
[0005] One conventional approach to providing fault-tolerant file and record locking features to the NAS clustered architecture assigns ownership of all file and record |locks| to individual servers in the NAS gateway cluster. When a server in the NAS gateway receives a lock request, the server determines whether another server owns the lock. If another server owns the requested lock, the server receiving the lock request issues a demand-lock request via an inter-cluster message to the server owning the lock to initiate transfer of ownership of the lock to the server that received the current lock request.
[0006] The protocol for this approach requires ownership of locks to be transferred via an inter-cluster protocol requiring a set of messages; consequently, this approach entails some network overhead. This approach fails to address issues that appear when the cluster is used as a multi-protocol NAS server platform. Further, this approach does not address lock contention among the various network file system protocols nor does it address server failures and server failure recovery.
[0007] Another conventional |approach| forwards lock requests on a given file system to a single server thus avoiding the need for inter-cluster coordination while serving the request. A request received through a server that is not assigned to handle the lock requests for the underlying file system requires forwarding to the proper server, resulting in significant overhead. This approach does not support load balancing. Further, no effort is made by this approach to address multi-protocol support for locking at the cluster servers.
[0008] Yet another conventional approach utilizes state information managed by a file server; the state information is maintained among the clients of the distributed system. When a server fails in this approach, the state maintained by the clients is transferred to the backup server. This approach requires that clients maintain knowledge of the identity of a backup server. Clients are required to keep the server state and rebuild that server state on a new server in the case of a server failure. Further, this approach provides no means to fail-back the clients to the original server after recovery from failure.
[0009] Presently, there exists no known method for providing a distributed locking solution that works properly for various network file access protocols in the framework of a clustered NAS running on top of cluster file systems. What is therefore needed is a system, a computer program product, and an associated method for preserving state for a cluster of file servers in a cluster file system, in the presence of load-balancing, failover, and fail-back events. The need for such a file and record locking solution for a clustered NAS running on top of a cluster file system has heretofore remained unsatisfied.
SUMMARY OF THE INVENTION
[0010] The present invention satisfies the need for file and record locking solution for a clustered NAS running on top of a cluster file system, and presents a system, a computer program product, and an associated method (collectively referred to herein as “the system” or “the present system”) for preserving a state for a cluster of file servers in the presence of load-balancing, failover, and fail-back events. The present system employs a lock ownership scheme in which ownership identifiers are guaranteed to be unique across clustered servers and across various protocols the clustered servers may be exporting; i.e., the present system comprises a global naming scheme for tracking lock ownership. The present system extends the concept of lock ownership to a global space that comprises NAS clients and cluster file system clients. This concept of lock ownership prevents collisions that may occur in conventional systems when local access to the file system is combined with NAS file serving.
[0011] The present system provides a mechanism for proper lock recovery upon cluster server failover and fail-back; this mechanism also enables lock transfers during load balancing events. The present system is consistent with multi-protocol NAS file serving.
[0012] The present system also solves common problems that arise in clustered NAS servers such as, uncommitted writes upon server failures and load balancing events. The present system further maintains a seamless, cluster file system space that is exported to clients.
[0013] The present system utilizes back-end storage device access provided by a clustered or distributed file system running in cluster servers; the cluster servers act as servers for the file system (or systems) hosted in the backend storage devices. The cluster servers are driven by cluster software (a cluster system) running on the cluster servers. The cluster system is capable of maintaining a persistent cluster state that outlives server failures. The cluster system further maintains a consistent cluster membership from which a leader can be elected to drive recovery tasks needed during server failures. The cluster is resilient to leader failures; i.e., once the leader server has gone down a new leader can be selected from the remaining membership.
[0014] The underlying cluster file system supports distributed record locking. The recovery of such locks is driven by leases granted to cluster servers that acquire the locks. The underlying cluster file system further supports optional delegation of byte-range locking to the cluster file system clients.
[0015] The present system carries out implicit lock transfers, requiring no message forwarding or explicit lock transfers between cluster servers as in conventional systems. The present system further manages server failures and fail-back in the cluster. The present system supports the presence of a load-balancing device in front of the cluster that may be used to balance network file system traffic.
[0016] The present system is complete, simpler than conventional systems, and minimizes changes to single server NAS code. The present system solves distributed locking issues in the framework of multi-protocol NAS file serving and concurrent local access to the cluster file system being exported via NAS protocols.
[0017] The present system allows any server in the NAS cluster to receive a lock request and process it directly; no forwarding is required.
[0018] Compared to conventional approaches, the present system does not assign ownership of locks to specific servers in the NAS cluster. Instead, the client owns a lock and the underlying instance of the lock in the cluster file system; no ownership transfer is required. The protocol of the present system requires only a change of lease ownership; the change in lease ownership is performed in a lazy manner, implicitly along with lock requests.
[0019] Compared to conventional systems, the present system does not require clients to maintain additional information. The present system consider all the server nodes equal peers and does not rely on a concept of primary and backup servers. This is an advantage because clients are not required to have prior knowledge of identity of a backup server. Instead, all servers have access to all state information so that there is no suspension of ongoing requests, transfer of state information from clients to backup server, and reconstruction of state prior to failure as it is usually the case for competing approaches. The present system provides a method to fail-back the clients to the original server after recovery from failure. The present system utilizes a combination of the clients and the backend shared file system to maintain server state.
[0020] This distributed lock management of the present system is designed to deal with file/lock access migration due to either NAS server failover and fail-back events or load balancing reconfigurations. The present system further eliminates a need for an explicit lock migration protocol, resulting in improved efficiency and simplicity compared to conventional approaches.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The various features of the present invention and the manner of attaining them will be described in greater detail with reference to the following description, claims, and drawings, wherein reference numerals are reused, where appropriate, to indicate a correspondence between the referenced items, and wherein:
[0022] FIG. 1 is a schematic illustration of an exemplary cluster file system using more than one IP address in which a state management system of the present invention can be used;
[0023] FIG. 2 is a schematic illustration of an exemplary cluster file system using a virtual IP address in which a state management system of the present invention can be used;
[0024] FIG. 3 is a high-level architecture of a server state module of the state management system of FIGS. 1 and 2 ;
[0025] FIG. 4 is a high-level architecture of a client of the cluster file system of FIGS. 1 and 2 ; and
[0026] FIG. 5 comprises FIGS. 5A and 5B and represents a method of operation of the state management system of FIGS. 1 and 2 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] The following definitions and explanations provide background information pertaining to the technical field of the present invention, and are intended to facilitate the understanding of the present invention without limiting its scope:
[0028] Fail-back: Transfer of operations back to a machine that recovered after a failure from the machine in the cluster that replaced it after the failure. Transfer of operations comprises functionality, clients, and state of the recovered machine.
[0029] Failover: Transfer of operations of a failing machine in a cluster to another machine in the cluster. Transfer comprises the functionality, clients, and state of the failing machine.
[0030] Load Balancing: Distributing work requests among all the machines in the cluster such that all the machines get an even share of the work
[0031] FIG. 1 illustrates an exemplary high-level architecture of a shared storage database 100 comprising a state management system 10 (the “system 10 ”). System 10 comprises a server state module 15 , a state metadata module 20 , and a server state and metadata 25 . System 10 further comprises a software programming code or computer program product that is typically embedded within, or installed on a computer. Alternatively, system 10 can be saved on a suitable storage medium such as a diskette, a CD, a hard drive, or like devices. While system 10 is described in terms of a cluster file system, it should be clear that system 10 is applicable as well to, for example, any shared storage database system.
[0032] The shared storage database 100 comprises a server 1 , 30 , a server 2 , 35 , through a server N, 40 (collectively referenced as clustered servers 45 ). The clustered servers 45 function as a network attached storage gateway. Each of the clustered servers 45 comprises a clustering module 90 that allows the clustered servers 45 to perform as a cluster. One of the clustered servers 45 plays a role of a cluster leader. Upon failure of the cluster leader, the clustering module 90 elects a surviving member of the clustered servers 45 to perform the role of the cluster leader. Each of the clustered servers 45 accesses data or files stored in a storage device 50 through a storage area network (SAN) 55 . The shared storage database 100 further comprises a metadata server 60 . The metadata server 60 accesses the server state and metadata 25 stored on the storage device 50 via storage area network 55 .
[0033] Clients, such as the client 1 , 65 , client 2 , 70 , through client N, 75 , (collectively referenced as clients 80 ) access the clustered servers 45 through a network 85 . Each of clients 80 may represent an application such as, for example, a database management system, accessing data that is stored on the storage device 50 . Each of the clustered servers 45 comprises a file server protocol such as, for example, network file system (NFS), for managing access by clients 80 to the data on the storage device 50 . Clients 80 each comprise software that communicates with any of the clustered servers 45 to access data in the storage device 50 .
[0034] The shared storage database 100 supports distributed byte-range (i.e. file record) locking. The recovery of these locks is driven by timed leases. The shared storage database 100 further supports delegation of byte-range locks to clustered server 45 and recall of such delegations. Lock state is maintained at the metadata server 60 and the clustered servers 45 .
[0035] FIG. 2 illustrates an exemplary cluster file system 200 utilizing a load balancer 205 . The load balancer 205 accepts all requests from clients 80 and routes them to the clustered servers 45 , balancing the processing and I/O load among the clustered servers.
[0036] The shared storage database 100 assigns a different global IP address to each of the cluster servers 45 . The architecture of the shared storage database 100 is a multi-IP address architecture. The clustered servers 45 are hidden behind the load balancer 205 in the cluster file system 200 . The load balancer 205 acts as a traffic-switching server that balances the traffic of the cluster file system 200 among the clustered servers 45 . The architecture of the cluster file system 200 is a virtual IP architecture. In the cluster file system 200 , a single global IP address is exported to clients 80 by the load balancer 205 . The shared storage database 100 and the cluster file system 200 are fault tolerant with respect to failures in the clustered servers 45 . In the shared storage database 100 , fault tolerance is achieved through IP address takeover. In the cluster file system 200 , fault tolerance is provided by the load balancer 205 that ceases to distribute traffic to any of the clustered servers 45 that fail during regular operation.
[0037] The cluster file system 200 and the shared storage database 100 perform in a similar manner; the shared storage database 100 is referenced hereinafter as representative of the shared storage database 100 and the cluster file system 200 .
[0038] Lock requests are received through any of the clustered servers 45 and then handed to the clustering module 90 . The clustered servers 45 act as servers and also as clients to the shared storage database 100 . The metadata server 60 comprises one or more servers. The clustered servers 45 satisfy requests by using data cached by a local cache or by forwarding requests to the metadata server 60 . Locks are implemented on top of a file record lock feature provided by the shared storage database 100 . The clustered servers 45 maintain ownership of the lock leases (but not the locks themselves).
[0039] System 10 supports and enforces file and file record locks even in the presence of server failures in the clustered servers 45 and load balancing redirection events initiated by the load balancer 205 . The lock state is generally maintained at the metadata server 60 ; consequently, load-balancing events are supported almost transparently as no extra messages or lock migration is required.
[0040] FIG. 3 illustrates a high-level hierarchy of the server state module 15 . The server state module 15 comprises a cluster manager 305 , a network lock manager 310 , a network status manager 315 , and a cache 320 for storing state information. FIG. 4 illustrates a high-level hierarchy of a client 405 representative of each of the clients 80 . Client 405 comprises a client network lock manager 410 and a client network status manager 415 .
[0041] Any of clients 80 may interact with any of the clustered servers 45 . In the following discussion, the client 1 , 65 , is used as a generic representative of clients 80 while the server 1 , 30 , is used as a generic representative of the clustered servers 45 . While discussed in terms of a lock, it should be clear that the performance of system 10 is applicable to, for example, any state.
[0042] The client 1 , 65 , issues requests to the server 1 , 30 . The server 1 , 30 , accesses data on the storage device 50 and performs I/O operations. The client 1 , 65 , mounts file systems exported by the server 1 , 30 , so that the file systems appear as a local file system to the client 1 , 65 .
[0043] The client 1 , 65 , may lock a file or a file record on any of the clustered servers 45 ; these locks may be monitored or unmonitored. Monitored locks are fault-tolerant against failures in clients 80 or the clustered servers 45 . If the client 1 , 65 , obtains a lock on the server 1 , 30 , and the server 1 , 30 , subsequently fails, the lock can be reinstated by the client 1 , 65 , when the server 1 , 30 , recovers from failure. If the client 1 , 65 , fails while holding a monitored lock on a server 1 , 30 , the server 1 , 30 , discards the lock when notified of the failure by the client 1 , 65 .
[0044] For the purposes of illustration, server 2 , 35 , is designated as the cluster leader (further referenced herein as cluster leader 35 ). Any of the cluster servers 45 may be selected to perform the role of cluster leader. The cluster leader 35 maintains a persistent state in the shared storage database 100 ; the persistent state is used through the lock recovery process. The persistent state is created to monitor each of the cluster servers 45 that are holding a lock. The persistent sate is placed in a cluster-shared persistent state. The availability of the cluster-shared persistent state enables each of the cluster servers to readily access state information, enabling failover.
[0045] After a failure by one of the cluster servers 45 , the cluster leader 35 controls the lock recovery process. The cluster leader 35 sets all of the cluster servers 45 to a grace period state and sends notifications to clients 80 . The grace period state is in effect for a predetermined window of time, or grace period. The cluster leader 35 further processes lease expiration requests initiated by the metadata server 60 . The metadata server 60 monitors a leadership status of the cluster servers 45 ; consequently, the metadata server 60 can communicate lease expiration events to the cluster leader 35 to enable lock recovery.
[0046] When one of the cluster servers 45 fails or reboots, all of the cluster servers 45 are concurrently placed in the grace period. Placing all of the cluster servers 45 in the grace period prevents any of clients 80 from stealing the locks held through a failed or rebooted server. Once all of the cluster servers 45 are placed in the grace period state, the cluster leader 35 sends change of state notifications to each of clients 80 that held locks through the failed or rebooted server. Each of clients 80 can then reclaim their locks. The grace period provides sufficient opportunity to reclaim the locks. A client that holds locks on different files across additional servers may reclaim locks that are still in place. System 10 is designed to manage such a scenario.
[0047] System 10 coordinates the clustering module 90 and the server state module 15 . More precisely, the clustering module 90 may release a locking state created by one of the clustered servers 45 (e.g., the server 1 , 30 ) if the clustering module 90 believes that the server 1 , 30 , has failed. Releasing this lock state without notifying clients 80 that hold locks on the server 1 , 30 , exposes those locks to being acquired by other clients 80 . To prevent this scenario, system 10 provides an interface that enables the cluster leader 35 to initiate a grace period/lock reclaim sequence when the clustering module 90 is about to give up locks acquired through a server such as the server 1 , 30 .
[0048] When the clustering module 90 is about to expire the lease that enforces the locks held by one of clients 80 , it notifies the server state module 15 so that the server state module 15 can initiate a grace-period/lock-recovery sequence before the clustering module 90 gives up the locks. The server state module 15 initiates the grace period in all of the clustered servers 45 that remain. The server state module 15 then notifies the distributed file system when all of the clustered servers 45 are in the grace period state. At this time, the clustering module 90 is free to expire the lease and release the lock state for the server 1 , 30 , the server that has failed.
[0049] If the server state module 15 fails to notify the clustering module 90 that the grace period has been established, the lease for the failed server in the shared storage database 100 is forced to expire after a longer wait period. Such a situation may occur if the communication between the cluster leader 35 and the shared storage database 100 is disrupted for a prolonged period of time or when all the clustered servers 45 in the shared storage database 100 fail. Consequently, system 10 is resilient to failures in the NAS cluster manager.
[0050] The cluster manager 305 is designed to be fault tolerant because the server where the cluster manager 305 is running (i.e., the cluster leader 35 ) may fail. System 10 makes the cluster manager 305 fault tolerant by saving the state of the cluster manager 305 in a cluster persistent state. If the lock recovery process is interrupted by a failure of the cluster leader 35 , the lock recovery process is re-started in any of the remaining clustered servers 45 selected as a new cluster leader. The cluster manager 305 can restart the lock recovery procedure from the beginning without any side effects: locks that have already been reclaimed may be reclaimed again and those that have not been reclaimed can be reclaimed under the rule of the new cluster leader. The new cluster manager establishes a cluster-wide grace period and re-issues all the necessary messages to clients 80 .
[0051] If the shared storage database 100 issues a lease expiration notification to the cluster manager 305 during periods of failure of the cluster leader 35 , the shared storage database 100 accumulates notifications of lease expirations until a new cluster manager registers with the shared storage database 100 . When the new cluster manager registers, accumulated lease expiration notifications are forwarded to the new cluster manager. The new cluster manager acknowledges and processes the accumulated lease expiration notifications.
[0052] Lock ownership is defined by a state tuple comprising a network address of the client requesting the lock (e.g., the client 1 , 65 ) and a process ID of a process issuing a lock request. This information is readily available in typical lock requests and can be passed to the shared storage database 100 . Identifying locks with the state tuple ensures that conflicting lock requests passed to the shared storage database 100 through the clustered servers 45 are detected and only a single lock request is granted at any time. Further, conflicting lock requests received through different protocols can be detected by the shared storage database 100 . Lock requests generated by local access to the file system exported by the clustered servers 45 can also be enforced against network-file-system-protocol-originated locks at the level of the underlying file system.
[0053] Single server lock acquisition and recovery performs as follows, wherein the client 1 , 65 , represents any one of clients 80 and the server 1 , 30 , represents any one of the clustered servers 45 . When the client 1 , 65 , acquires a lock through the server 1 , 30 , the network status monitor 215 at the server 1 , 30 , starts monitoring changes of status at the client 1 , 65 , while the client network status manager 315 at the client 1 , 65 , starts monitoring changes of status at the server 1 , 30 . Changes of status in this context represent reboots or restarts of the process of the network status monitor 315 or the client network status monitor 415 .
[0054] In existing single-server configuration, lock recovery works as described next. If the server 1 , 30 , reboots or restarts the process of the network status monitor 215 on the server 1 , 30 , the state of the lock acquired by any of clients 80 through the server 1 , 30 , is lost. For proper operation, system 10 relies on each of the clients 80 reclaiming locks during the grace period after, for example, the server 1 , 30 , reboots or restarts.
[0055] When the server 1 , 30 , is restarted, the network status monitor 315 on the server 1 , 30 , checks the persistent database of clients 80 that are monitored and notifies those clients 80 about the reboot or restart of the server 1 , 30 . At that time, the server 1 , 30 , enters the grace period in which all new lock requests are rejected or delayed; only reclaim lock requests are honored during the grace period. Clients 80 that are holding locks at the reboot server are notified through the protocol of the network status monitor 315 and urged to reclaim their previous locks during the grace period of the server 1 , 30 , before any of the other clients 80 are given an opportunity to appropriate locks previously held by the server 1 , 30 . The lock recovery procedure just described does not directly extend to the architectures of the clustered servers 45 ; consequently, system 10 describes a lock recovery scheme that can be used in environments such as the clustered file system 100 .
[0056] System 10 maintains a copy of the lock state for each of the clustered servers 45 in cache 320 of the server that is holding the lock. For example, a copy of the lock state for all the locks held by the server 1 , 30 , is held in the cache 320 of the server 1 , 30 . Furthermore, system 10 maintains a copy of the states in the server state and metadata module 25 . Maintaining a copy of the states in the server state and metadata module 25 improves performance when additional lock requests are routed through the same server in the clustered servers 45 . For example, a record of a lock that has been granted is kept in one of the clustered servers 45 such as, for example, the server 1 , 30 . Subsequent, conflicting lock requests routed through the server 1 , 30 , may be blocked or refused without being passed to the shared storage database 100 and potentially generating extra network messages in the storage area network 50 .
[0057] When a lock request arrives at the exemplary server 1 , 30 , the cache 320 of the server 1 , 30 , is checked for conflicting locks. If such check fails to produce a conflicting lock, the lock request is then handed to the shared storage database 100 where the lock is granted or rejected based on whether the state is present at the server state and metadata module 25 . The server 1 , 30 , caches granted locks. Lock state maintained in clustered servers 45 is volatile and can be reconstructed in any of the other clustered servers 45 using the state maintained in the server state and metadata 25 .
[0058] When using the load balancer 205 in the cluster file system 200 , lock caching at the clustered servers 45 is disabled to prevent state consistency issues.
[0059] System 10 comprises the cluster manager 305 that controls the network lock manager 310 and the network status monitor. System 10 comprises a level of support from the shared storage database 100 such that lease expiration events in the shared storage database 100 can be communicated to the cluster manager 305 . The shared storage database 100 supports file locks whose enforcement is based on client-based leases: clustered servers 45 obtain and renew leases that enforce locks acquired on various files. The shared storage database 100 has an interface to notify external users of lease expiration events and synchronize the lease expiration events with external software.
[0060] When one of the clustered servers 45 such as, for example, the server 1 , 30 , fails while holding a lock on behalf of one of clients 80 such as the client 1 , 65 , the client 1 , 65 is notified of the failure of the server 1 , 30 . Upon receiving this notification, the client 1 , 65 , proceeds to reclaim locks acquired through server 1 , 30 . Notifications of failure by one of the clustered servers 45 (further referenced herein as a lease expiration notification) may be originated by the shared storage database 100 or by system 10 .
[0061] The shared storage database 100 notifies the cluster leader 35 about a lease expiration event of one of servers 45 via a notification interface of system 10 . The shared storage database 100 requests the removal of the failed server (the server 1 , 30 ) from membership in the clustered servers 45 and waits until the removal has been completed. The shared storage database 100 sets the network lock manager 310 in each of the clustered servers 45 that remain to the grace period state to prevent any new lock requests from reaching the failed server (the server 1 , 30 ). The shared storage database 100 issues a lease expiration notification acknowledgment to the cluster leader 35 so that the lock state for the server whose lease has expired (the server 1 , 30 ) can be released. The shared storage database 100 notifies each of clients 80 through the network status monitor 315 on each of clients 80 that locks held through the failed server (i.e., the server 1 , 30 ) are required to be reclaimed.
[0062] Each of clients 80 whose lock state in the server 1 , 30 , has been lost attempt to reclaim locks through any of the servers 45 that remain. The reclaim requests of the network lock manager 310 are mapped to reclaim requests of the shared storage database 100 . The network lock manager 310 performs this mapping. Locks being reclaimed are most likely available and are granted to each of the clients 80 requesting the lock. These locks may be in the unlocked state or in the lease-expired state where reclaims can be accepted. The network lock manager 310 on each of the cluster servers 45 is in the grace period state as the reclaims occur; consequently, locks that can be reclaimed are not granted to any of clients 80 requesting those locks with non-reclaim lock operations.
[0063] However, after the cluster system has acknowledged a lease expiration notification and before clients 80 reclaim previously held locks, the locks become available for other file access protocols or local cluster file system requests. Consequently, a lock may be lost to another file access protocol during the grace period for one file access protocol. If any of clients 80 affected by the failure of the server 1 , 30 , held locks through additional servers in the clustered servers 45 , the clients 80 , may end up reclaiming locks that are still active. In this case, the reclaim may or may not be routed through the server 1 , 30 , that currently holds the lock. In either case, each of the cluster servers 45 accept reclaims based on ownership of the lock by any of clients 80 . In this scenario, the shared storage database 100 updates ownership of the lease on the locks.
[0064] If a failure of any of the clustered servers 45 is originally detected by the cluster system, processing of the locks is similar to the process of detecting failures through the lease expiration notifications previously described. When the cluster manager 305 on the cluster leader 35 detects a server failure, the cluster manager 305 ejects the failed server from the cluster membership. The cluster manager 305 sets the network lock manager 310 on each of the clustered servers 45 to the grace period state. The cluster manager 305 issues a notification to the network status monitor 315 of clients 80 that held locks through the failed server.
[0065] System 10 may issue a “lease expired” message to the cluster manager 305 while the steps described above are in progress; in this case this message may be acknowledged and otherwise ignored. If the lease expiration notification arrives when another instance of the server has been accepted to the clustered servers 45 , the server may be dropped and reintroduced at a later time without significant side effects other than delays in the reintegration of the server to the clustered servers 45 .
[0066] If the lease expiration message arrives once the server has been dropped from the clustered servers 45 , the message is acknowledged and otherwise ignored. When the recovery is initiated by the cluster system, it is possible that reclaims arrive for locks that are being leased by the server that was just dropped. It may take some time for the shared storage database 100 to detect a server drop event. In this scenario, the reclaim request is routed through one of the other clustered servers 45 ; the metadata server 60 honors the lock request by swapping the lease ownership of the lock to the server that received the reclaim.
[0067] When access to a file is migrated from one of the clustered servers 45 to another of the clustered servers 45 for load balancing purposes, no special action is necessary by system 10 . Lock requests are percolated to the cluster file system 10 with the state tuple (process ID, client ID) passed by a client such as the client 1 , 65 . As a requirement, all lock requests may be honored by the shared storage database 100 no matter which of the clients 80 originates the lock request provided that a lock range involved is free or the owner of the lock matches any preexisting owner. This enables system 10 to acquire locks on behalf of any of clients 80 through one of the cluster servers 45 and later release the lock through a different one of the clustered servers 45 when access to the underlying file is migrated. Lock state does not need to be migrated along with access to a file; consequently locks are not exposed to being lost during file migration.
[0068] The cluster manager 305 drives lock recovery by invoking programs that handle the various phases of lock recovery. When a server leaves the clustered servers 45 (Server Remove), the cluster manager 305 drives the lock recovery through recovery phases that are separated by barrier synchronization between all of the clustered servers 45 . In an initial phase of recovery, the cluster manager 305 sets the network status monitor 315 for each of the clustered servers 45 to a grace-period state. The cluster manager 305 issues acknowledgments (via an acknowledgement protocol) for all outstanding lease expiration notifications issued related to the server that is leaving the clustered servers 45 , and sends notification messages to all affected clients. Only the cluster manager 305 of the cluster leader 35 makes this call.
[0069] The cluster manager 305 of the cluster leader 35 monitors in persistent state the servers that are being removed from the clustered servers 45 so it can send a notification for each of the removed servers once all the remaining servers in the clustered servers are in the grace period state. In a next phase of the recovery, the cluster manager 305 further notifies all clients 80 affected by the removal of servers from the clustered servers 45 via a status monitor protocol. Only the cluster manager 305 on the cluster leader 35 performs this action. Such notification is issued for every server removed from the clustered servers 45 .
[0070] Any additions of servers to the clustered servers 45 are delayed until the lock recovery phases described above are completed. Server removals, including removal of the cluster leader 35 , are dealt with during the recovery process phases described above. If system 10 is setting the grace period and another server is removed from the clustered servers 45 , system 10 sets the grace period in all remaining servers once again. If a server is removed from the clustered servers 45 after the grace period is set, system 10 restarts recovery from the initial phase but sends notification only for the server just removed.
[0071] The network status monitor 315 tracks each of clients 80 that hold locks through the specific server in the clustered servers 45 that owns the lease of the lock. This state is kept because clients 80 may need to reassert their locks upon failure of one of the clustered servers 45 . To enable lock recovery, this state may be preserved across reboot and failures of a server. To ensure such state is preserved across failure events, the state is stored in the server state and metadata module 25 .
[0072] The network status monitor 315 on each of the clustered servers 45 maintains a list of clients 80 that own locks on their respective server in different directories of the shared storage database 100 . As an example, the shared storage database 100 comprises two servers, a server N 0 and a server N 1 , each with a network status monitor 315 . A state of the network status monitor 315 for each of the two servers is stored in the shared file system in different paths: /Shared_FS/N 0 /statd and /Shared_FS/N 1 /statd. If server N 0 fails, system 10 notifies clients 80 that held locks acquired through server N 0 as recorded in the /Shared_FS/N 0 /statd/ directory. System 10 further removes the state corresponding to the failed server, server N 0 , from a directory of the shared storage database 100 . The cluster manager 305 of the cluster leader 35 is in charge of generating the notification messages sent to clients 80 .
[0073] A mount protocol for the clustered file system 100 relies on information that is made persistent through all the clustered servers 45 for proper operation of clustered implementations. An initial piece of information that is shared by all the clustered servers 45 is the export list; i.e., which directories are available to clients 80 and related permissions for those directories. The mount protocol verifies each mount request against an export list defined for the clustered servers 45 . The export list is distributed to each of the clustered servers 45 because the routing of the mount requests is not known in advance. Given the above requirements, the export list can be kept in the shared storage database 100 where it is available to all of the clustered servers 45 concurrently and where the export list can be consistently modified using a configuration utility.
[0074] The mount protocol comprises a mount list maintained in a persistent state to monitor which file systems are mounted by each of clients 80 . The mount list is maintained in the server state and metadata module 25 and on each of the clustered servers 45 . System 10 uses the mount list when recovering from a failure by one of the clustered servers 45 . After one of the clustered servers 45 crashes and reboots, the mount list enables the failed server to remember file systems mounted by each of clients 80 previously. Consequently, each of clients 80 is provided uninterrupted access to their respective file systems without requiring each of clients 80 to remount their respective file system.
[0075] The information in the mount list is further shared with the shared storage database 100 . The shared storage database 100 keeps a memory image of the mount list to restrict client access to those file systems that have been successfully mounted with the correct permissions. System 10 further manages a situation where one of the clustered servers 45 receives the mount request and another of the clustered servers 45 receives file operations on the mounted file system. Furthermore, when one of clients 80 issues a mount request, any of the clustered servers 45 is able to process the request regardless of which of the clustered servers 45 received the request.
[0076] One or more of the clustered servers 45 may update the mount list at a given time. Consequently, the mount list is locked when access to a mount state file is required. The shared storage database 100 maintains a memory copy in cache 320 of the mount list to check for client permission to access various file systems. System 10 requires each of the clustered servers 45 to update their cache copy of their mount state with every modification that occurs at any of the clustered servers 45 . In one embodiment, a shared file comprising the mount list is read by the cluster system after each update to the mount list. In another embodiment, the clustered servers 45 memory maps the file comprising the mount list so that updates to the mount list are reflected into memory. In a further embodiment, the cluster system can read the shared file comprising the mount list each time the cluster system fails to verify client permissions with the information held in memory.
[0077] System 10 comprises support for asynchronous writes in which clients 80 can write data to the clustered servers 45 without requiring the clustered servers 45 to commit data to stable storage before replying to the write request. Once one of clients 80 (i.e., the client 1 , 65 ) completes the asynchronous write operations, it issues a commit request to direct the server (i.e., the server 1 , 30 ) to flush data to stable storage. Upon receiving a write or commit request, the server 1 , 30 , provides the client 1 , 65 , with a number, called the verifier, which the client 1 , 65 , may present to the server 1 , 30 , upon subsequent write or commit operations. The verifier is a cookie, included in write and commit responses sent to the client 1 , 65 , that the client 1 , 65 , can use to determine if the server 1 , 30 , has changed state (i.e., failed) between a call to write and a subsequent call to write or commit.
[0078] There are scenarios in which a client such as the client 1 , 65 , may be misguided into believing that an asynchronous write was actually committed to persistent store, even when the asynchronous write may have not have been flushed to persistent storage. For example, consider the scenario where the client 1 , 65 , sends an asynchronous write to one of the clustered servers 45 such as the server 1 , 30 . The server 1 , 30 , fails before committing the write to persistent store. Now consider that the client 1 , 65 , is failed over to another of the clustered servers 45 that happens to have the same verifier as the failed server, the server 1 , 30 . In this situation, the client 1 , 65 , may issue a commit to the new server and receive a successful response even when the data written to the server 1 , 30 , was actually lost.
[0079] System 10 prevents this scenario by ensuring that each of the clustered servers 45 use different write verifiers at all times. This requirement is coordinated via cluster system when each of the clustered servers boots up. In one embodiment, the start time of each of the clustered servers 45 is used as the verifier. Clocks among the clustered servers 45 are kept synchronized and are always started sequentially to ensure that all of the clustered servers 45 maintain a different verifier at all times.
[0080] System 10 requires each of the clustered servers 45 to enter the grace period during failover and fail-back operations, potentially preventing all new lock operations during that period. However, the server state and metadata module 25 on the storage device 50 keeps track of the servers in the clustered servers 45 that have failed or are in the process of failing back. Further, the server state and metadata module 25 monitors the locks acquired through that failed server. Consequently, the server state and metadata module 25 could implement selective responses indicating whether a set of locks is in the grace period or not; furthermore, lock requests that occur during the grace period but that do not refer to locks that are going through grace period could be granted.
[0081] In one embodiment, system 10 comprises a selective grace period in which locks that have no relationship to servers in transition states are available if they are not locked. For example, a file lock, lock L 1 , is held through the server 1 , 30 , and the server 1 , 30 fails. The server state and metadata module 25 has a record of the fact that the server 1 , 30 , is holding lock L 1 . Any lock request coming in for a lock that does not conflict with lock L 1 receives a normal response from the server state and metadata module. If the requested lock conflicts with any outstanding lock, the requested lock is rejected. If the lock does not conflict with any outstanding lock, the requested lock is accepted. If the incoming lock conflicts with lock L 1 , the server state and metadata module 25 responds with a message that access to lock L 1 is in a grace period. In this manner, system 10 avoids the need to place all of the clustered servers 45 in a grace period during failover and fail-back events with respect to all locks.
[0082] System 10 supports exporting single or additional network addresses to the clients 85 . Consequently, subtle differences exist regarding the type of the notification sent by the network status monitor 315 to clients 80 during server failure or reboot in each scenario. If a single IP address is exported to clients 80 (as in cluster file system 200 ), the notifications issued by the network status monitor 315 comprise the single IP address. If more than one network address is exported to clients 80 , the clustered servers 45 issue the notifications of network status monitor 315 to clients 80 with the network address of the failing server. In the multi-IP address architecture of shared storage database 100 , a server may have been serving additional network addresses (of other previously failed servers) and it may need to send the notifications of the network status monitor 315 to clients 80 using those server addresses as well. Sending these extra notifications ensures that system 10 works even when a server network address is repeatedly taken over by remaining servers in the clustered servers 45 until no additional servers remain in the clustered servers 45 .
[0083] FIG. 5 ( FIGS. 5A, 5B ) represents a method ( 500 ) of system 10 . A server (one of the clustered servers 45 ) registers for lease expiration notifications with a metadata server 60 (step 505 ) The registration process for the server experiences a timed wait (step 525 ). If an acknowledgement is not received from the metadata server 60 (decision step 525 ), the server returns to step 505 . Otherwise, system 10 determines whether a lease for a lock has expired (decision step 535 ).
[0084] If a lease has not expired, system 10 determines whether a server has been removed (decision step 540 ). If not, system returns to step 535 . If the lease has expired (decision step 535 ), system 10 removes the failed server from the clustered servers 45 (step 545 ). The clustered servers 45 are placed in a timed wait (step 550 ). If system 10 does not receive an acknowledgement of the server removal (decision step 555 ), system 10 returns to step 545 .
[0085] If the server has been removed (decision step 555 ), system 10 asks all of the clustered servers 45 to go into a grace period (step 560 ). Likewise, if the server is found to be removed in decision step 540 , system 10 asks all the clustered servers 45 to go into a grace period (step 560 ).
[0086] System enforces a timed wait corresponding to the grace period (step 565 ). System 10 determines whether all the clustered servers 45 are in the grace period (decision step 570 ). If not, processing returns to step 560 until all the clustered servers 45 are in the grace period. System 10 notifies all the clients 80 that are holding locks through the failed server about the server failure (step 575 ). Processing then returns to step 535 .
[0087] It is to be understood that the specific embodiments of the invention that have been described are merely illustrative of certain applications of the principle of the present invention. Numerous modifications may be made to the system and method for preserving state for a cluster of file servers in a cluster file system, in the presence of load-balancing, failover, and fail-back events described herein without departing from the spirit and scope of the present invention. Moreover, while the present invention is described for illustration purpose only in relation to network addresses storage, it should be clear that the invention is applicable as well to, for example, any network file sharing protocol. Furthermore, while the present invention is described for illustration purpose only in relation to a lock, it should be clear that the invention is applicable as well to, for example, any state.
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A state management system preserves a state for a cluster of file servers in a cluster file system in the presence of load balancing, failover, and fail-back events. The system provides a file and record locking solution for a clustered network attached storage system running on top of a cluster file system. The system employs a lock ownership scheme in which ownership identifiers are guaranteed to be unique across clustered servers and across various protocols the clustered servers may be exporting. The system supports multi-protocol clustered NAS gateways, NAS gateway server failover and fail-back, and load-balancing architectures. The system further eliminates a need for a lock migration protocol, resulting in improved efficiency and simplicity.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of application Ser. No. 07/158,652, filed Feb. 22, 1988, which is a continuation of application Ser. No. 06/771,248, filed Aug. 30, 1985 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to cloned DNA sequences indistinguishable from genomic RNA and DNA of lymphadenopathy-associated virus (LAV), a process for their preparation and their uses. It relates more particularly to stable probes including a DNA sequence which can be used for the detection of the LAV virus or related viruses or DNA proviruses in any medium, particularly biological samples containing any of them. The invention also relates to polypepetides, whether glycosylated or not, encoded by said DNA sequences.
Lymphadenopathy-associated virus (LAV) is a human retrovirus first isolated from the lymph node of a homosexual patient with lymphadenopathy syndrome, frequently a prodrome or a benign form of acquired immune deficiency syndrome (AIDS). Subsequently, over LAV isolates were recovered from patients with AIDS or pre-AIDS. All available data are consistent with the virus being the causative agent of AIDS.
A method for cloning such DNA sequences has already been disclosed in British Patent Application Nr. 84 23659, filed on Sep. 19, 1984. Reference is hereafter made to that application as concerns subject matter in common with the further improvements to the invention disclosed herein.
SUMMARY OF THE INVENTION
The present invention aims at providing additional new means which are not only useful for the detection of LAV or related viruses, (hereafter more generally referred to as "LAV viruses"), or "Human Immunodeficiency Virus Type 1" or simply "HIV-1"), but also now means that have more versatility, particularly in detecting specific parts of the genomic RNA of said viruses whose expression products are not always directly detectable by immunological methods.
The present invention further aims at providing polypeptides containing sequences in common with polypeptides encoded by the LAV genomic RNA. It relates even more particularly to polypeptides comprising antigenic determinants included in the proteins encoded and expressed by the LAV genome occurring in nature. An additional object of the invention is to further provide means for the detection of proteins related to LAV virus, particularly for the diagnosis of AIDS or pre-AIDS or, to the contrary, for the detection of antibodies against the LAV virus or proteins related therewith, particularly in patients afflicted with AIDS or pre-AIDS or more generally in asymptomatic carriers and in blood-related products. Finally, the invention also aims at providing immunogenic polypeptides, and more particularly protective polypeptides for use in the preparation of vaccine compositions against AIDS or related syndrome.
The present invention relates to additional DNA fragments, hybridizable with the genomic RNA or LAV as they will be disclosed hereafter, as well as with additional cDNA variants corresponding to the whole genomes of LAV viruses. It further relates to DNA recombinants containing said DNAs or cDNA fragments.
The invention relates more particularly to a cDNA variant corresponding to the whole of LAV retroviral genomes, which is characterized by a series of restriction sites in the order hereafter (from the 5' end to the 3' end).
The coordinates of the successive sites of the whole LAV genome (restriction map) are indicated hereafter too, with respect to the Hind III site (selected as of coordinate 1) which is located in the R region. The coordinates are estimated with an accuracy of ±200 bp:
______________________________________ Hind III 0 Sac I 50 Hind III 20 Pst I 800 Hind III 1 100 Bgl II 1 500 Kpn I 3 500 Kpn I 3 900 Eco RI 4 100 Eco RI 5 300 Sal I 5 500 Kpn I 6 100 Bgl II 6 500 Bgl II 7 600 Hind III 7 850 Bam HI 8 150 Xho I 8 600 Kpn I 8 700 Bgl II 8 750 Bgl II 9 150 Sac I 9 200 Hind III 9 250______________________________________
Another DNA variant according to this invention optionally contains an additional Hind III approximately at the 5 550 coordinate.
Reference is further made to FIG. 1 which shows a more detailed restriction map of said whole DNA (λJ19).
An even more detailed nucleotide sequence of a preferred DNA according to the invention is shown in FIGS. 4-12 hereafter.
The invention further relates to other preferred DNA fragments which will be referred to hereafter.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional features of the invention will appear in the course of the non-limitative disclosure of additional features of preferred DNAs of the invention, as well as of preferred polypeptides according to the invention. Reference will further be had to the drawings in which:
FIG. 1 is the restriction map of a complete LAV genome (clone λJ19):
FIGS. 2 and 3 show diagrammatically parts of the three possible reading phases of LAV genomic RNA, including the open reading frames (ORF) apparent in each of said reading phases:
FIGS. 4-12 show the successive nucleotide sequences of a complete LAV genome. The possible peptide sequences in relation to the three possible reading phases related to the nucleotide sequences shown are also indicated:
FIGS. 13-18 reiterate the sequence of part of the LAV genome containing the genes coding for the envelope proteins, with particular boxed peptide sequences which corresponds to groups which normally carry glycosyl groups.
FIGS. 19-26 reiterate the whole DNA sequence of the LAV genome.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The sequencing and determination of sites of particular interest were carried out on a phage recombinant corresponding to λJ19 disclosed in the abovesaid British Patent application Nr. 84 23659. A method for preparing it is disclosed in that application.
The whole recombinant phage DNA or clone λJ19 (disclosed in the earlier application) was sonciated according to the protocol of DEININGER (1983). Analytical Biochem. 129, 216. The DNA was repaired by a Klenow reaction for 12 hours at 16° C. The DNA was electrophoresed through 0.8% agarose gel and DNA in the size range of 300-600 bp was cut out and electroeluted and precipitated. Resuspended DNA (in 10 mM Tris, pH 8:0.1 mM EDTA) was ligated into M13mp8 RF DNA (cut by the restriction enzyme SmaI and subsequently alkaline phosphated), using T4 DNA- and RNA-ligases (Maniatis et al (1982)--Molecular cloning--Cold Spring Harbor Laboratory). An E. coli strain designated as TG1 was used for further study. This strain has the following genotype:
Δlac pro, supE, thi.F traD36, proAB, lacI q , ZΔM15,r -
This E. coli TG1 strain has the peculiarity of enabling recombinants to be recognized easily. The blue colour of the cells transfected with plasmids which did not recombine with a fragment of LAV DNA is not modified. To the contrary cells transfected by a recombinant plasmid containing a LAV DNA fragment yield white colonies. The technique which was used is disclosed in Gene (1983), 26, 101.
This strain was transformed with the ligation mix using the Hanahan method (Hanahan, O. (1983) J. Mol. Biol. 166, 557). Cells were plated out on tryptone-agarose plate with IPTG and X-gal in soft agarose. White plaques were either picked and screened or screened directly in situ using nitrocellulose filters. Their DNAs were hybridized with nick-translated DNA inserts of pUC18 Hind III subclones of λJ19. This permitted the isolation of the plasmids or subclones of λ which are identified in the table hereafter. In relation to this table it should also be noted that the designation of each plasmid is followed by the deposition number of a cell culture of E. coli TGI containing the corresponding plasmid at the "Collection Nationale des Cultures de Micro-organismes" (C.N.C.M.) of the Pasteur Institute in Paris, France. A non-transformed TGI cell line was also deposited at the C.N.C.M. under Nr. I-364. All these deposits took place on Nov. 15, 1984. The sizes of the corresponding inserts derived from the LAV genome have also been indicated.
TABLE______________________________________Essential features of the recombinant plasmids______________________________________pJ19 - 1 plasmid (I-365) 0.5 kb Hind III - Sac I - Hind III pJ19 - 17 plasmid (I-367) 0.6 kb Hind III - Pst 1 - Hind III pJ19 - 6 plasmid (I-366) 1.5 kb Hind III (5') Bam HI Xho I Kpn I Bgl II Sac I (3') Hind III pJ19 - 13 plasmid (I-368) 6.7 kb Hind III (5') Bgl II Kpn I Kpn I Eco RI Eco RI Sal I Kpn I Bgl II Bgl II Hind III (3')______________________________________
Positively hybridizing M13 phage plates were grown up for 5 hours and the single-stranded DNAs were extracted.
M13mp8 subclones of λJ19 DNAs were sequenced according to the dideoxy method and technology devised by Sanger et al. Sanger et al (1977), Proc. Natl. Acad. Sci. USA. 74, 5463 and M13 cloning and sequencing handbook, AMERSHAM (1983). The 17-mer oligonucleotide primer α- 35 SdATP (400 Ci/mmol, AMERSHAM), and 0.5X-5X buffer gradient gels (Biggen, M. D. et al (1983.) Proc. Natl. Acad. Sci. USA, 50, 3963) were used. Gels were read and put into the computer under the programs of Staden (Staden R. (1982), Nucl. Acids Res. 10, 4731). All the appropriate references and methods can be found in the AMERSHAM M13 cloning and sequencing handbook.
The complete sequence of λJ19 was deduced from the experiments as further disclosed hereafter.
FIGS. 4-12 provide the DNA nucleotide sequence of the complete genome of LAV. The numbering of the nucleotides starts from a left most Hind III restriction site (5' AAG. . . ) of the restriction map. The numbering occurs in tens whereby the last zero number of each of the numbers occurring on the drawings is located just below the nucleotide corresponding to the nucleotides designated. That is the nucleotide at position 10 is T, the nucleotide at position 20 is C, etc.
Above each of the lines of the successive nucleotide sequences there are provided three lines of single letters corresponding to the amino acid sequence deduced from the DNA sequence (using the genetic code) for each of the three reading phases, whereby said single letters have the following meanings.
A: alanine
R: arginine
K: lysine
H: histidine
C: cysteine
M: methionine
W: tryptophan
F: phenylalanine
Y: tyrosine
L: leucine
V: valine
I: isoleucine
G: glycine
T: threonine
S: serine
E: glutamic acid
D: Aspartic acid
N: asparagine
Q: glutamine
P: proline.
The asterisk signs "*" correspond to stop codons (i.e. TAA, TAG and TGA).
Starting above the first line of the DNA nucleotide sequence of FIG. 4, the three reading phases are respectively marked "1", "2", "3", on the left handside of the drawing. The same relative presentation of the three theoretical, reading phases is then used over all the successive lines of the LAV nucleotide sequence.
FIGS. 2 and 3 provide a diagrammatized representation of the lengths of the successive open reading frames corresponding to the successive reading phases (also referred to by numbers "1", "2" and "3" appearing in the left handside part of FIG. 2. The relative positions of these open reading frames (ORF) with respect to the nucleotide structure of the LAV genome is referred to by the scale of numbers representative of the respective positions of the corresponding nucleotides in the DNA sequence. The vertical bars correspond to the positions of the corresponding stop codons.
(1) The "gag gene" (or ORF-gag)
The "gag gene" codes for core proteins. Particularly it appears that a genomic fragment (ORF-gag) thought to code for the core antigens including the p25, p18 and p13 proteins is located between nucleotide position 236 (starting with 5' CTA GCG GAG 3') and nucleotide position 1759 (ending by CTCG TCA CAA 3'). The structure of the peptides or proteins encoded by parts of said ORF is deemed to be that corresponding to phase 2.
The methionine amino acid "M" coded by the ATG at position 260-262 is the probable initiation methionine of the gag protein precursor. The end of ORF-gag and accordingly of gag protein appears to be located at position 1759.
The beginning of p25 protein, thought to start by a P-I-V-Q-N-I-Q-G-Q-M-V-H . . . amino acid sequence is thought to be coded for by the nucleotide sequence CCTATA . . . starting at position 656.
Hydrophilic peptides in the gag open reading frame are identified hereafter. They are defined starting from amino acid 1=Met (M) coded by the ATG starting from 260-2 in the LAV DNA sequence.
Those hydrophilic peptides are
______________________________________12-32 amino acids inclusive 37-46 " " 49-79 " " 88-153 " " 158-165 " " 178-188 " " 200-220 " " 226-234 " " 239-264 " " 288-331 " " 352-361 " " 377-390 " " 399-432 " " 437-484 " " 492-498 " "______________________________________
The invention also relates to any combination of these peptides.
2) The "pol gene" (or ORF-pol)
FIGS. 4-12 also show that the DNA fragments extending from nucleotide position 1555 (starting with 5'TTT TTT . . . 3' to nucleotide position 5086 is thought to correspond to the pol gene. The polypeptidic structure of the corresponding polypeptides is deemed to be that corresponding to phase 1. It stops at position 4563 (end by 5'G GAT GAG GAT 3').
These genes are thought to code for the virus polymerase or reverse transcriptase.
3) The envelope gene (or ORF-env)
The DNA sequence thought to code for envelope proteins is thought to extend from nucleotide position 5670 (starting with 5'AAA GAG GAG A . . . 3') up to nucleotide position 8132 (ending by . . . ACT AAA GAA 3'). Polypeptide structures of sequences of the envelope protein correspond to those read according to the "phase 3" reading phase.
The start of env transcription is though to be at the level of the ATG codon at positions 5691-5693.
Additional features of the envelope protein coded by the env genes appear on FIGS. 13-18. These are to be considered as paired FIGS. 13 and 14; 15 and 16; 17 and 18, respectively.
It is to be mentioned that because of format difficulties.
FIG. 14 overlaps to some extent with FIG. 13,
FIG. 16 overlaps to some extent with FIG. 15,
FIG. 18 overlaps to some extent with FIG. 17.
Thus, for instance, FIGS. 13 and 14 must be considered together. Particularly the sequence shown on the first line on the top of FIG. 13 overlaps with the sequence shown on the first line on the top of FIG. 14. In other words, the starting of the reading of the successive sequences of the env gene as represented in FIGS. 13-18 involves first reading the first line at the top of FIG. 13 then proceeding further with the first line of FIG. 14. One then returns to the beginning of the second line of FIG. 13, then again further proceed with the reading of the second line of page 14, etc. The same observations then apply to the reading of the paired FIGS. 15 and 16, and paired FIGS. 17 and 18, respectively.
The locations of neutralizing epitopes are further apparent in FIGS. 13-18. Reference is more particularly made to the boxed groups of three letters included in the amino acid sequences of the envelope proteins (reading phase 3) which can be designated generally by the formula N-X-S or N-X-T, wherein X is any other possible amino acid. Thus, the initial protein product of the env gene is a gly-coprotein of molecular weight in excess of 91,000. These groups are deemed to generally carry glycosylated groups. These N-X-S and N-X-T groups with attached glycosylated groups form together hydrophilic regions of the protein and are deemed to be located at the periphery of and to be exposed outwardly with respect to the normal conformation of the proteins. Consequently, they are considered as being epitopes which can efficiently be brought into play in vaccine compositions.
The invention thus concerns with more particularity peptide sequences included in the env proteins and excizable therefrom (or having the same amino acid structure), having sizes not exceeding 200 amino acids.
Preferred peptides of this invention (referred to hereafter as a, b, c, d, e, f are deemed to correspond to those encoded by the nucleotide sequences which extend, respectively, between the following positions:
______________________________________a) from about 6095 to about 6200 b) from about 6260 to about 6310 c) from about 6390 to about 6440 d) from about 6485 to about 6620 e) from about 6860 to about 6930 f) from about 7535 to about 7630______________________________________
Other hydrophilic peptides in the env open reading frame are identified hereafter. They are defined starting from amino acid 1=lysine (K) coded by the AAA at position 5670-2 in the LAV DNA sequence.
These hydrophilic peptides are
______________________________________ 8-23 amino acids inclusive 63-78 " " 82-90 " " 97-123 " " 127-183 " " 197-201 " " 239-294 " " 300-327 " " 334-381 " " 397-424 " " 466-500 " " 510-523 " " 551-577 " " 594-603 " " 621-630 " " 657-679 " " 719-758 " " 780-803 " "______________________________________
The invention also relates to any combination of these peptides.
4) The other ORF
The invention further concerns DNA sequences which provide open reading frames defined as ORF-Q, ORF-R and as "1", "2", "3", "4", "5", the relative position of which appears more particularly in FIGS. 2 and 3.
These ORFs have the following locations:
______________________________________ORF-Q phase 1 start 4478 stop 5086 ORF-R phase 2 start 8249 stop 8896 ORF-1 phase 1 start 5029 stop 5316 ORF-2 phase 2 start 5273 stop 5515 ORF-3 phase 1 start 5383 stop 5615 ORF-4 phase 2 start 5519 stop 5773 ORF-5 phase 1 start 7966 stop 8279______________________________________
The LTR (long terminal repeats) can be defined as lying between position 8560 and position 160 (end extending over position 9097/1). As a matter of fact the end of the genome is at 9097 and, because of the LTR structure of the retrovirus, links up with the beginning of the sequence: ##STR1##
The invention concerns more particularly all the DNA fragments which have been more specifically referred to hereabove and which correspond to open reading frames. It will be understood that the man skilled in the art will be able to obtain them all, for instance by cleaving an entire DNA corresponding to the complete genome of a LAV species, such as by cleavage by a partial or complete digestion thereof with a suitable restriction enzyme and by the subsequent recovery of the relevant fragments. The different DNAs disclosed in the earlier mentioned British Application can be restored to also as a source of suitable fragments. The techniques disclosed hereabove for the isolation of the fragments which were then included in the plasmids referred to hereabove and which were then used for the DNA sequencing can be used.
Of course other methods can be used. Some of them have been exemplified in the earlier British Application. Reference is, for instance, made to the following methods.
a) DNA can be transfected into mammalian cells with appropriate selection markers by a variety of techniques, such as calcium phosphate precipitation, polyethylene glycol, protoplast-fusion, etc.
b) DNA fragments corresponding to genes can be cloned into expression vectors for E. coli, yeast or mammalian cells and the resultant proteins purified.
c) The provival DNA can be "shot-gunned" (fragmented), into procaryotic expression vectors to generate fusion polypeptides. Recombinants producing antigenically competent fusion proteins can be identified by simply screening the recombinants with antibodies against LAV antigens.
The invention also relates more specifically to cloned probes which can be made starting from any DNA fragment according to this invention, thus to recombinant DNAs containing such fragments, particularly any plasmids amplifiable in procaryotic or eucaryotic cells and carrying said fragments.
Using the cloned DNA fragments as a molecular hybridization probe--either by marking with radionucleotides or with fluorescent reagents--LAV virion RNA may be detected directly in the blood, body fluids and blood products (e.g. of the antihemophilic factors such as Factor VIII concentrates) and vaccines, i.e. hepatitis B vaccine. It has already been shown that whole virus can be detected in culture supernatants of LAV producing cells. A suitable method for achieving that detection comprises immobilizing virus onto a support, e.g. nitrocellulose filters, etc., disrupting the virion, and hydribizing with labelled (radiolabelled or "cold" fluorescent- or enzyme-labelled) probes. Such as approach has already been developed for Hepatitis B virus in peripheral blood (according to SCOTTO, J. et al. Hepatology (1983), 3, 379-384).
Probes according to the invention can also be used for rapid screening of genomic DNA derived from the tissue of patients with LAV related symptoms to see if the proviral DNA or RNA is present in host tissue and other tissues.
A method which can be used for such screening comprises the following steps: extraction of DNA from tissue, restriction enzyme cleavage of said DNA, electrophoresis of the fragments and Southern blotting of genomic DNA from tissues, and subsequent hybridization with labelled cloned LAV provival DNA. Hybridization in situ can also be used.
Lymphatic fluids and tissues and other non-lymphatic tissues of humans, primates and other mammalian species can also be screened to see if other evolutionary related retrovirus exist. The methods referred to hereabove can be used, although hybridization and washings would be done under non-stringent conditions.
The DNA according to the invention can also be used for achieving the expression of LAV viral antigens for diagnostic purposes.
The invention also relates to the polypeptides themselves which can be expressed by the different DNAs of the inventions, particularly by the ORFs or fragments thereof, in appropriate hosts, particularly procaryotic or eucaryotic hosts, after transformation thereof with a suitable vector previously modified by the corresponding DNAs.
These polypeptides can be used as diagnostic tools, particularly for the detection of antibodies in biological media, particularly in sera or tissues of persons afflicted with pre-AIDS or AIDS, or simply carrying antibodies in the absence of any apparent disorders. Conversely, the different peptides according to this invention can be used themselves for the production of antibodies, preferably monoclonal antibodies specific of the different peptides respectively. For the production of hybridomas secreting said monoclonal antibodies, conventional production and screening methods are used. These monoclonal antibodies, which themselves are part of the invention, than provide very useful tools for the identification and even determination of relative proportions of the different polypeptides or proteins in biological samples, particularly human samples containing LAV or related viruses.
Thus, all of the above peptides can be used in diagnostics as sources of immunogens or antigens free of viral particles, produced using non-permissive systems, and thus of little or no biohazard risk.
The invention further relates to the hosts (procaryotic or eucaryotic cells) which are transformed by the above-mentioned recombinants and which are capable of expressing said DNA fragments.
Finally, it also relates to vaccine compositions whose active principle is to be constituted by any of the expressed antigens, i.e. whole antigens, fusion polypeptides or oligopeptides in association with a suitable pharmaceutically or physiologically acceptable carrier.
Preferably, the active principles to be considered in that field consist of the peptides containing less than 250 amino acid units, preferably less than 150 as deducible from the complete genomes of LAV, and even more preferably those peptides which contain one or more groups selected from N-X-S and N-X-T as defined above. Preferred peptides for use in the production of vaccinating principles are peptides (a) to (f) as defined above. By way of example having no limitative character, there may be mentioned that suitable dosages of the vaccine compositions are those which enable administration to the host, particularly human host, ranging from 10 to 500 micrograms per kg, for instance 50 to 100 micrograms per kg.
For the purpose of clarity, FIGS. 19 to 25 are added. Reference may be made thereto in case of difficulties of reading blurred parts of FIGS. 4 to 12.
Needless to say that FIGS. 19-26 are merely a reiteration of the whole DNA sequence of the LAV genome.
Finally, the invention also concerns vectors for the transformation of eucaryotic cells of human origin, particularly lymphocytes, the polymerases of which are capable of recognizing the LTRs of LAV. Particularly, said vectors are characterized by the presence of a LAV LTR therein, said LTR being then active as a promoter enabling the efficient transcription and translation in a suitable host of the above defined DNA insert coding for a determined protein placed under its controls.
Needless to say that the invention extends to all variants of genomes and corresponding DNA fragments (ORFs) having substantially equivalent properties, all of said genomes belonging to retroviruses which can be considered as equivalents of LAV.
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This invention is in the field of lymphadenopathy virus which has been desogmated Human Immunodeficiency Virus Type 1 (HIV-1) This invention relates to a diagnostic means and method to detect the presence of DNA, RNA or antibodies of the lymphadenopathy retrovirus associated with the acquired immune deficiency syndrome or of the lymphadenopathy syndrome by the use of DNA fragments or the peptides encoded by said DNA fragments. The invention further relates to the DNA fragments, vectors comprising them and the proteins expressed.
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This application is a continuation of application Ser. No. 067,251, filed June 26, 1987, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the manufacture of a magnetic recording medium which is typically used in the form of a magnetic recording tape, a floppy disc or the like, and more particularly to a method of smoothing magnetic films.
2. Description of the Prior Art
It is known that a web may be coated with a coating material while it is being moved, thereby forming a film over the surface of the web. In general, the thus-formed film is subjected to a smoothing process in order to make the surface of the film smooth and uniform. In the field of manufacture of magnetic recording media such as magnetic tapes and floppy discs, various processes for smoothing magnetic films are practiced in order to improve the performance of such media.
A method in which a coated film is smoothed by contacting a doctor bar or a doctor knife to the surface of the film and in direct contact therewith has heretofore been widely used as a typical smoothing process, as disclosed in Japanese Patent Examined Publication No. 11336/1973. However, such a prior-art process involves disadvantage in that scratches or other defects are easily formed due to air movement or foreign matter which might have an influence during the contacting movement between such doctor element and the film and in that, since a web vibrates with respect to the doctor bar or doctor knife which is disposed in a fixed manner, the film formed on the web is likely to vary in thickness.
A film-smoothing method employing an air doctor is known as a method which does not involve such disadvantages to any substantial extent. This method has heretofore been utilized in smoothing a film formed by a coating paint having relatively low viscosity. Such a method is carried out in the following manner. A magnetic paint is coated on a web and a film is thus formed thereon. Before the film dries and solidifies, the wet film is supported and moved on a supporting roll and at the same time air is blown onto the film by means of an air doctor. The film is smoothed by the pressure of the air.
In another conventional method, while the film is being moved, a flexible film sheet is brought into contact with the surface of the film so as to smooth the latter, as disclosed in Japanese Patent Unexamined Publication No. 53631/1974. This method enables various improvements in erasure of cyclic unevenness in thickness, twill-like patterns and longitudinal stripes in reverse roll coating, as well as erasure of plate cylinder patterns in gravure roll coating. This brings about a significant improvement in the coated state of the film. Typically, in such a method, a magnetic paint is coated on a web while the latter is being moved, and a film is formed over the web. Before the film dries and solidifies, the surface of a flexible sheet is brought into contact with the wet film, the flexible sheet being secured at its one end to a fixed bar. Thus, the film is made smooth and uniform by the shear stress produced between the surface and the web.
In such a prior-art method, the air doctor has a significant effect in smoothing films formed of low-viscosity magnetic paint. It is, however, inferior with respect to magnetic paint having relatively high viscosity; for example, mottled patterns may be formed on the film.
Also, the aforesaid smoothing method employing a flexible sheet has advantage in that, since the sheet the ability to move in correspondence with the vibration which might occur during movement of the web, it is possible to reduce variations in film thickness. In general, this smoothing process is effective with respect to low-viscosity magnetic paint. However, since a magnetic paint containing fine grain magnetic particulates is commonly used for a magnetic recording medium of the type suitable for high-density recording, the viscosity of the paint per se is increased. It is therefore difficult for any of the prior-art methods to meet the demand for high-precision smoothness of such a film.
Such difficulty is typically derived from the fact that a magnetic paint of the aforementioned type exhibits large thixotropic properties, that is, exhibits large variations in viscosity in response to shearing; for example, the viscosity is reduced by imparting shear stress to the paint and also, if the shear stress is eliminated, the paint recovers its viscosity relatively quickly. Therefore, the paint coated on a web may be reduced in viscosity at the time that shear stress is imparted to the web during a coating process. However, the paint recovers its viscosity by virtue of its thixotropic properties before the smoothing step is effected following the coating step. In addition, since, after the coating, a diluting solvent evaporates from the film extremely quickly, another layer having relatively high viscosity is formed on the surface of the film. Accordingly, in this state, when air is blown onto the film through the nozzle of the air doctor, the surface layer having relatively high viscosity is partially broken, thereby producing small clumps. This constitutes a cause of formation of mottled patterns on the film. In order to prevent this phenomenon, consideration has been given to increasing the level of the air pressure of the air doctor. However, this measure produces no significant effect upon the occurrence of this phenomenon; rather, the increased air pressure may cause scattering of the paint which forms the film. The scattered paint may stick to the film, and this could result in lowering of the quality of smoothness.
Also, in a state wherein the aforesaid layer with relatively high viscosity is formed, if the flexible sheet is brought into contact with the web, the layer is subjected to shear stress between the web and the flexible sheet and thus its viscosity starts to decrease. However, before the viscosity of the film is reduced to a relatively low level uniformly in the direction of its thickness, the film passes by an associated edge of the flexible sheet. It is therefore impossible to obtain a uniform smoothing effect, and this may also result in the occurrence of longitudinal stripes, uneven thickness or mottled patterns.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention o provide a method of smoothing a magnetic film which enables an improved smoothing process without unevenness in coating.
It is another object of the present invention to provide a method in which the surface of a film formed of a magnetic paint having high viscosity suitable for high-density recording can be effectively smoothed by means of a typical air doctor method.
It is still another object of the present invention to provide a method in which the surface of a film formed of a magnetic paint having high viscosity suitable for high-density recording can be effectively smoothed by means of a typical flexible sheet.
To these end, the present invention provides a method of smoothing a magnetic film comprising the steps of:
coating a magnetic paint over the surface of a web to form a film thereon; and
moving the web in an alternating current magnetic field before the film thereon is dried so that smoothing of the film may be effected.
In accordance with the present invention, the aforesaid process causes fluctuation of the magnetic particulates contained in the paint so as to uniformly reduce the viscosity of the film, thereby preventing the formation of a high-viscosity layer on the film surface. Accordingly, the surface of the film can be easily smoothed by means of either an air doctor or a flexible sheet.
More specifically, when an alternating current magnetic field is caused to act upon the magnetic paint, the magnetic particulates contained in the latter are fluctuated by the interaction between the magnetic field and the magnetic momentums of the individual magnetic particulates. In a magnetic field having nonuniform magnetic flux density, the magnetic particulates are generally moved toward a large magnetic flux density concurrently with its rotary motion. Accordingly, if a wet film which does neither dry nor solidify is moved transversely of an alternating current magnetic field showing the distribution of magnetic flux density in the direction of thickness of the film, a kind of spiral flow of magnetic paint is produced in a cross-sectional area of the film. This flow of the magnetic paint caused by the alternating current magnetic field imparts a shearing force to the wet film in the form of a kind of agitation. Thus, the viscosity of the film is uniformly reduced in the directions of its thickness and width and also the high-viscosity layer is prevented from being formed over the surface of the film. This enables the film surface to be uniformly smoothed by means of the air doctor or the flexible sheet.
It has heretofore been unknown that smoothing may be effected by the action of an alternating current magnetic field in the aforesaid manner. U.S. Pat. No. 4,547,393 discloses a surface treatment employing a smoothing sheet in which the smoothing sheet is subjected to a direct current magnetic field for a magnetic-field orientation treatment so that the orientation of planar magnetic particulates is improved. As previously described, the method of this invention is capable of achieving an improved smoothing effect by generating a spiral flow of magnetic paint in the direction of thickness of the film by means of an alternating current magnetic field. Accordingly, it will be appreciated that the objects, features and arrangement of the invention differ from those of the method described in the specification of U.S. Pat. No. 4,547,393.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a first preferred embodiment of the present invention and shows a method of smoothing a magnetic film by means of an air doctor;
FIG. 2 is a schematic view of a second preferred embodiment of the present invention and shows a method of smoothing a magnetic film by means of a flexible sheet; and
FIG. 3 is a graph showing the relationships between the frequency of an applied alternating current magnetic field, the intensity thereof and the squareloop ratio of obtained magnetic films, for a parameter of the intensity of the magnetic field.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention will be described below with reference to the accompanying drawings.
It is to be noted that an alternating-current magnetic field generator used in the invention need not necessarily include an electro-magnet having a special structure. It is therefore possible to employ any generator of the type in which a non-uniform magnetic field can be applied in the direction of thickness of the film formed on a web, but it is preferable to produce a magnetic field as uniformly as possible in the direction of the width of the web. It is also preferred that the frequency and intensity of the alternating current magnetic field employed are suitably selected in accordance with the characteristics of a magnetic paint employed and the state of a film.
EXAMPLE 1
As shown in FIG. 1, a web 1 composed of a polyester film having a width of 300 mm was moved in a running direction at a speed of 100 m/min, and a magnetic coating material having a viscosity of about 10 poise was coated over the moving web 1 by a reverse-roll method, thereby forming a film 2 having a thickness of 16 μm. The magnetic paint was obtained by uniformly dispersing γ-iron oxide powder and non-magnetic pigment in a mixed solution containing methyl ethyl ketone, xylole and a copolymer of vinyl chloride and vinyl acetate. A core 8 had a length of 400 mm, a width of 100 mm and a thickness of 70 mm as well as an E-shaped form in crosssection perpendicular to the length of the core 8, as shown in FIG. 1. A coil 9 was wrapped around such a core 8 to form an electro-magnet 6, and was disposed such that its length was arranged at right angles with the direction of movement of the web 1. An alternating current was made to flow in the electro-magnet 6 at a frequency of 60 Hz, and an alternating current magnetic field of about 1000 gauss was created with the pole face 10 separated from the web 1 by a distance of about 10 mm. In addition, an air doctor 4 having a nozzle width of 0.5 mm was disposed such that the distance between the tip of a nozzle 5 and the adjacent surface of the film 2 was 4 mm and the direction of air blowing was inclined at an angle of about 45 degrees with respect to the surface of the film 2. Before the film 2 dried and solidified, that is, while it was in a non-dry state, the web 1 was moved in an alternating current magnetic field 7 as the former was supported on a supporting roll 3. In this state, air was blown through the air nozzle at an air pressure of about 0.1 kg/cm 2 , thereby effecting smoothing. In this case, it is preferable that the supporting roll 3 is made of a non-magnetic material having high electrical resistance owing to the fact that such a material does not heat and that a magnetic field can be effectively adjusted. In addition, prior-art methods such as orientation treatment, drying, solidification, calendering and cutting were conducted, thereby preparing a video tape. No cyclical unevenness in thickness, mottled patterns and longitudinal stripes were found on the thus-obtained video tape, and a high degree of gloss of the tape was achieved. In addition, such video tape exhibited superior characteristics in relation to S/N ratio and the occurrence of dropouts.
EXAMPLE 2
Instead of the reverse roll coating method used in Example 1, coating was effected by a gravure coating method, and a smoothing treatment similar to that performed in Example 1 was carried out under the conditions that the intensity of the magnetic field was 1500 gauss with the air pressure of the air doctor being 0.15 kg/cm 2 . The thus-obtained film had no gravure cylindrical plate patterns, and no unevenness in coating, mottled patterns, longitudinal stripes were found thereon. In consequence, a high degree of gloss was achieved and it was therefore possible to obtain a video tape superior in characteristics relative to S/N ratio and the occurrence of dropouts.
EXAMPLE 3
As shown in FIG. 2, in the same manner as that of Example 1, the web 1 composed of a polyester film having a width of 300 mm was moved at a speed of 100 m/min, and a magnetic paint with a viscosity of about 10 poise was coated over the moving web 1 by a reverse-roll method, thereby forming the film 2 having a thickness of 16 μm in its wet state. The magnetic paint was obtained by uniformly dispersing γ-iron oxide powder and non-magnetic pigment in a mixed solution containing methyl ethyl ketone, xylole and a copolymer of vinyl chloride and vinyl acetate. The core 8 had a length of 400 mm, a width of 100 mm and a thickness of 70 mm as well as an E-shaped form in cross-section taken in the direction perpendicular to the length of the core 8, as shown in FIG. 2. The coil 9 was wrapped around the core 8 to form the electromagnet 6, and was disposed such that its longitudinal direction was arranged at right angles with the direction of movement of the web 1. An alternating current was made to flow in the electro-magnet 6 at a frequency of 60 Hz cycles per second, and an alternating current magnetic field of about 1000 gauss was created with the pole face 10 separated from the web 1 by a distance of about 10 mm. In addition, a flexible sheet 4 made of a polyester film having a width of 300 mm and a thickness of 25 μm was disposed such that the flexible sheet 4 was maintained in contact with the film through a length of 50 mm. The wet film 2 which did not dry nor solidify was moved in an alternating current magnetic field 7, and the flexible sheet 4 was brought into contact with the wet film 2, thereby effecting smoothing. In addition, various prior-art methods such as orientation treatment, drying, solidification, calendering and cutting were conducted, thereby preparing a video tape. No unevenness in coating, mottled patterns and longitudinal stripes were found on the thus-obtained video tape, and the tape had a uniform and smooth film surface. In addition, such tape had superior characteristics relative to S/N ratio and the occurrence of dropouts.
EXAMPLE 4
Instead of the reverse roll coating method used in Example 3, coating was effected by a gravure coating method, and a smoothing treatment similar to that performed in the aforesaid Example 3 was carried out under similar conditions. The thus-obtained film had no gravure cylindrical plate pattern, and no unevenness in coating, mottled patterns, longitudinal stripes was found thereon. In consequence, it was possible to obtain a video tape superior in characteristics relative to S/N ratio and the occurrence of dropouts.
The results of S/N ratios and dropouts obtained in the above-described Examples 1 to 4 are shown collectively in the following table. It is to be noted that the S/N ratio is the relative value with respect to "0" representative of a typical S/N ratio realized in the prior-art method.
TABLE______________________________________Example Example Example Example1 2 3 4 Prior Art______________________________________S/N (db) 0.5 to 1.0 0.5 to 1.0 0.5 to 1.0 0.5 to 1.0 0.00(Y signal)Number of 5 to 10 5 to 10 5 to 10 5 to 10 10 to 15Dropouts per minuteDepth: 16 dbWidth: 15 us______________________________________
FIG. 3 is a graph showing the influence of the frequency and intensity of an alternating current magnetic field and shows the square-loop ratios of the obtained magnetic film where the frequency is varied in the steps of 30, 60 and 90 Hz with the intensity of the magnetic field being changed in the steps of 500, 1000 and 1500 gauss. The distribution in each of Examples 1 to 4 is as shown in FIG. 3, and no difference is observed between the respective cases where the air doctor and the flexible sheet are employed. As can be seen from FIG. 3, no significant effect is produced when the intensity of magnetic field is approximately 500 gauss. However, when the intensity becomes 1000 or more gauss, a large effect can be obtained.
It is to be noted that, although the intensity of the magnetic field has no particular upper limit, an excessive intensity of magnetic field may lead to an increase in the overall size of the apparatus. In practice, therefore, about 1000 to 2000 gauss is preferable.
As described above, the present invention provides a method of smoothing a film comprising the steps of: coating a magnetic paint over the surface of a web to form a film thereon; and moving the web having the film thereon in a non-dry state in an alternating current magnetic field so that the viscosity of the wet film is reduced, thereby effecting smoothing of the film by means of an air doctor or a flexible sheet. Since this provides a film having a surface with a high accuracy of smoothness, the method of the invention is remarkably effective in improving the characteristics of various types of magnetic tape.
As a matter of course, the present invention is not confined solely to the arrangements used in the respective Examples 1 to 4. It will be appreciated that, even in a case where the speed of coating is changed or where another type of doctor blade is employed, it is possible to achieve an effect similar to that of the present Examples by suitably selecting the intensity and frequency of the alternating current magnetic field.
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This invention provides a method of smoothing a magnetic film comprising the steps of: coating a magnetic paint over the surface of a web to form a film thereon; and moving the web in an alternating current magnetic field before the film thereon being dried so that smoothing of the film may be effected. This method causes fluctuation of the magnetic particulates contained in the paint so as to uniformly reduce the viscosity of the film, thereby preventing the formation of a high-viscosity layer on the film surface. Accordingly, the surface of the film can be easily smoothed by means of either an air doctor or a flexible sheet.
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This is a continuation of application Ser. No. 557,333, filed Jul. 23, 1990, now abandoned, which, in turn, is a continuation-in-part of application U.S. Ser. No. 208,200, filed Jun. 17, 1988, now abandoned.
This invention relates to the separation of compounds having a molecular weight of less than 1000 daltons from bio-polymers. In particular, it relates to novel packing supports useful in liquid chromatography (LC) and solid phase extraction (SPE) techniques for separating drugs, metabolites, etc. from mixtures containing water soluble proteins.
BACKGROUND OF THE INVENTION
It is frequently necessary to confirm the presence of drug substances, their metabolites, etc., in serum or plasma and/or to measure the concentrations of these compounds. In other cases, it is necessary to separate bio-polymers from smaller substances as a step in purifying substances from biological or from biomass mixtures. Such analyses are carried out using liquid chromatographic systems as illustrated in FIG. 1 of the drawings. The invention is compatible with high performance liquid chromatographic systems but is not limited to them.
Most of the published data and methods in this area of research relate to the LC analysis of drugs, metabolites, etc., in serum or plasma. The ways the mixtures are sampled can be classified as indirect and direct sampling. Indirect sampling involves treatment of the sample to remove the proteins, e.g. by precipitation, followed by extraction of the compound(s) of interest into a protein-free solvent system. Although this method involves multi-step preparation before the sample can be analyzed by a particular LC method, it still attracts much of the practical attention. Direct sampling, or direct injection of the untreated sample on an LC analytical column, causes clogging of the column, resulting in increasing pressure drop, peak broadening, variation of retention times, etc., unless special precautions are taken. After each sample injection, or after a few injections, the column must be thoroughly washed to remove precipitated proteins, particularly when larger serum samples (≧10 μl) are needed to detect the analytes of interest at their therapeutic or biological levels.
A partial solution to the above problems was found in a combination of an analytical column and a precolumn and two delivery pumps in a column switching system. Usually, the serum sample is loaded onto a short precolumn under mobile phase conditions in which only the drug(s) elute onto the analytical column. When all the components of interest elute from the precolumn to the analytical column, a valve is switched so that one pump continues to deliver mobile phase for elution of the compounds of interest from the analytical column for separation, while the second pump delivers a washing solution to the precolumn for removal of the proteins. To avoid clogging, the precolumn is filled with relatively large particles, usually 20-40 μm, and is replaced frequently to avoid deterioration of the analytical column (W. Rothe, et al., J. Chromatog. 222 (1981) 13). Usually, both columns are filled with reversed phase packing, e.g. C 8 or C 18 bonded to a silica support.
To avoid protein accumulation in the precolumn and to speed up the washing step, a less hydrophobic packing has been used, butyl modified methacrylate, as manufactured by TosoH, Japan, and sold under the tradename TOYOPEARL™ BT-650M. In the loading cycle, 10-50% saturated ammonium sulfate (NH 4 ) 2 SO 4 aqueous mobile phase is used. Under such conditions, serum proteins are retained on the precolumn and the drugs elute to load the reversed phase analytical column. Then, by column switching, the analytical column is separately programmed, while the precolumn is cleaned of the retained proteins, using a buffer solution of lower ionic strength (G. Tamai, et al., Chromatographia 21 (1986) 519).
In another study, a polystyrene divinylbenzene resin, manufactured by Rohm and Haas, USA, and sold under the tradename Amberlite® XAD-2, was used as the packing in the precolumn to retain methaqualone (MTQ), while eluting the plasma proteins. After all the proteins are washed away (with a pH 9.3 buffer solution), the mobile phase is adjusted to elute MTQ (R. A. Hux, et al., Anal. Chem. 34 (1982) 113).
Another example of a two-modal HPLC system combines size exclusion chromatography (SEC) and reversed phase chromatography (RPLC) using two columns in a column switching system. Following exclusion of the biopolymers from the SEC column, the later eluting band of smaller molecular size compounds was backflushed to the RPLC analytical column (S. F. Chang, et al., J. Pharm. Sci. 72 (1983) 236).
All the above examples employ column switching which requires an elaborate chromatographic system, including a second solvent delivery system, a second column and a switching system. Moreover, the operation of the switching system itself requires labor or investment in additional control equipment.
A completely different approach was undertaken by Pinkerton, et al. (U.S. Pat. No. 4,544,485). They redesigned the packing of the analytical column in such a way that the proteins elute in the excluded volume (void volume) and the analytes are retained and separated on the same analytical column. This was accomplished by chemically modifying a hydrophilic diol phase with a hydrophobic oligopeptide, e.g. glycyl-(L-phenylalanine)n, where n=1,2, or 3. It is crucial to their invention that the diol phase is bonded to a porous silica gel having a pore diameter smaller than 80 angstroms. Following this modification, the phenylalanine moiety is enzymatically cleaved from the diol ligand with a protease. The cleavage is restricted to surface areas that are accessible to the protease, resulting in a support for which the diol ligands are only present on the external surface, while L-phenylalanine modified ligands are present in the internal surface, i.e., the pores of the packing material. The ligands that are not accessible to the enzyme are similarly not accessible to the serum proteins. Thus, these proteins are excluded from entering the pores and elute in the void volume, while the smaller molecules (e.g., drugs) can interact with the hydrophobic phenylalanine ligands (U.S. Pat. No. 4,544,485). This support, named internal surface reverse phase liquid chromatographic packing (IS-RP), can be used to analyze many serum sample without the damaging accumulation of proteinaceous precipitate seen on regular RPLC columns.
Conceptually, the study of Yoshida, et al., (Chromatographia 19 (1985) 466) is similar to that of Pinkerton. They adsorbed denatured plasma proteins on C 18 silica supports having small pore diameter. These supports no longer retained plasma proteins, but still showed reversed phase characteristics for smaller analytes. The phenomenon is depicted as similar to that of Pinkerton's model, or as having the proteinaceous precipitation limited to the externally exposed surface, thereby making the external surface hydrophilic, while keeping the non-exposed internal C 18 surface free of such precipitation and accessible for (hydrophobic) interaction with small compounds.
Thus an object of this invention is to provide a novel packing material for liquid chromatography which will allow the direct injection of biological fluids into the column.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a hydrophobic underlayer.
Still another object of this invention is to provide a chromatographic column which will shield and exclude large biopolymers but permit the partitioning of and hydrophobic interaction with small analytes.
Yet another object of this invention is to provide a novel shielded hydrophobic phase packing for chromatography adapted to bond to porous and non-porous silica supports.
Another object of this invention is to provide a chromatographic phase having a covalently bonded micellar surface.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and an anionic underlayer.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a cationic underlayer.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a chelating underlayer.
These and other objects of this invention may be seen by reference to the present specifications, claims, and drawings.
THE INVENTION
We have discovered shielded stationary-phase packing materials useful for liquid chromatography analysis and/or solid-phase extraction of mixtures containing proteinaceous compounds and small analytes, comprising:
a support;
an internal leash bonded to the support and bearing functionality that interacts with the small analytes; and
an external hydrophilic moiety bonded to the internal leash to form a hydrophilic external layer;
whereby the external hydrophilic external layer forms a water solvated interface which allows the small analytes to diffuse and interact with the internal leash but prevents interaction between the internal leash and the proteinaceous compounds.
In an alternative embodiment, we have discovered a shielded stationary-phase packing material for liquid chromatography analysis and/or solid-phase extraction of mixtures containing proteinaceous compounds and small analytes, comprising:
a support;
a hydrophilic polymeric network covalently bonded to the support; and
regions embedded within the network which contain functionality which interacts with the small analytes;
whereby small analytes will diffuse through the network and interact with the embedded regions and proteinaceous compounds will be excluded from such interaction.
We have further discovered a method of making these shielded stationary-phase packing materials, chromatography columns packed with these shielded stationary-phase packing materials, a method of liquid chromatographic separation which uses these chromatography columns, and a method of solid-phase extraction which uses these shielded stationary-phase packing materials.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a new concept providing novel LC or SPE packing materials which discriminate between water soluble proteins and smaller analytes on the bases of hydrophobic, ionic or other interactions. The novel LC or SPE packings of the present invention are (bonded) porous or non-porous supports in which an external, polar hydrophilic layer shields an underlayer which interacts with the small analytes, or in which pockets that interact with the small analytes are enclaved by a hydrophilic network. The underlayer or enclaved pockets may interact with the small analytes through hydrophobic, acidic, basic, ionic, chelating, or π--π bonding, or they may have other characteristics that cause them to interact and prevent or retard the elution of the small analytes. The present invention deals with supports having a bonded "micellar" layer, in which the micelles contain external polar and hydrophilic groups which are exposed to the mobile phase while shielding an underlayer that interacts with the small analytes. The present invention deals with a hydrophilic polymeric network that shields an underlayer that interacts with the small analytes, or such a network that contains enclaved regions that interact with the small analytes. Such hydrophilic shielding, when properly manipulated, can prevent water soluble proteins from interacting with the shielded part of the supports while allowing smaller substances to be retained or retarded by the interactive region, through hydrophobic, ionic, chelating or other interaction. These novel packings are termed shielded stationary phase (SSP).
The SSP packings of this invention are intended to eliminate the need for sample preparation procedures beyond the removal of particulate substances before the LC analysis. The packings are designed to elute the water soluble proteins, e.g. serum proteins, completely, or almost completely, in the void volume, and to retain drugs, metabolites, etc. Similarly, the packings of this invention can be used for separation of smaller analytes from water soluble proteins in the technique known as solid phase extraction, for small sample volumes to large scale industrial volumes. The SSP packing materials of the invention are conveniently produced from commercially available porous or non-porous silica supports, the surface of which is chemically modified with ligands or networks as described above. Similarly, the SSP packings can conveniently be produced from resins by modifying the surfaces of commercially available porous and nonporous materials, or by the direct preparation of such.
The use of micellar mobile phases in HPLC of proteins, e.g., nonionic surfactants, has been established in a number of studies, including use of direct plasma and serum injections (J. D. Dorsey, Chromatography 2 (1987) 13). Under these conditions, using for example a C 18 silica column, and a surfactant containing mobile phase, the surfactant saturates the stationary phase to form a double layer having a polar hydrophilic external interphase. The adsorption of many surfactants to such a reversed phase is strong enough to maintain the double layer even long after the additive has been removed from the mobile phase. Many water soluble proteins elute from such a column in the void volume, when the surfactant is selected from a groups of preferred detergents, e.g. the Tweens, bis-polyethyleneoxide derivatives of a fatty acid ester of sorbitol, as long as the double layer exists.
Albumins are known to associate with the Tweens and similar detergents below their critical micellar concentration (CMC) through hydrophobic patches located at the surface of these macromolecules, e.g. bovine serum albumin has four principal binding sites to adsorb deoxycholate, a biological "detergent" (A. Helenius, et al., Biochimica et Biophysica Acta 415 (1979) 29). A detergent-C 18 double layer can thus be drastically depleted of detergent molecules by injections of large serum samples due to the competitive adsorption of the serum albumin molecules to the surfactant.
Our invention attempts to mimic the chromatographic behavior of water soluble proteins on a "detergent modified" reversed phase by bonding appropriately designed ligands or polymeric phases to silica supports. Our invention is a new concept for chromatography in that it provides a covalently bonded micellar surface. The support consists of a non-polar spacer (R) which is interactive with small analytes and which is bonded to the support, and a hydrophilic end group (P). For a silica gel support (S) this can be represented by (S).tbd.Si--(R)--(P). The spacer R may be a hydrophobic moiety, in which case it will be a long chain aliphatic moiety, preferably containing 6-20 methylene groups, a crosslinked hydrocarbon, or a moiety that contains aryl groups. R may be a weak or strong anion-exchange group for ion pairing of acidic analytes, or a weak or strong cation-exchange group for ion pairing of basic analytes, or it may be a π--π donor to associate π--π acceptor analytes, or conversely a π--πacceptor to associate π--π donor analytes. It may bear chelating groups or other functional groups that will interact with the small analytes by complex formation. R may also be a combination of the groups and moieties described above. A preferred combination exists when R is a hydrophobic moiety which is substituted with weak or strong anion-exchange groups or weak or strong cation-exchange groups or π--π donor or acceptor groups or chelating groups, or combinations of these groups. P is the hydrophilic head containing one or more polar functional groups, and (S).tbd.Si is a siloxane bond (Si--O--Si) to the silica gel support. Alternatively, a hydrophilic polymeric network will shield an interactive, i.e. hydrophobic, cationic, anionic, chelating and the like, underlayer R or such a network containing interactive enclaved regions which provides a bonded phase with hydrophilic exterior, P, and interactive interior, R.
A particular advantage of the shielded stationary phase is the ability to select a phase from among the interactive underlayers or enclaved regions described above such that the retention times of particular analytes in chromatographic separations may be adjusted to resolve them from the large frontal peak of the proteins, or from other small analytes in a sample. One or more of the interactions described above may be employed to increase specific selectivity for particular analytes and make possible direct, quantitative analyses of complex mixtures such as biological matrix samples.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates a typical liquid chromatography system that consists of a solvent reservoir (10), sequentially connected to a pump (12), a mixer (14), an injector (16), a column (18), a detector (20), and a recorder or data collection unit (22). The column (18) is the device that contains the shielded stationary phase involved in the chromatographic separation.
FIG. 2 schematically shows the separation mechanism of a "micellar" shielded hydrophobic phase. The external polar heads form a hydrophilic layer (P) that is exposed to the protein and shields the hydrophobic underlayer (R). The proteins (G) come in contact with the noninteracting hydrophilic layer (P) while the small analytes (A) are partitioned and retained by the hydrophobic under layer (R).
FIG. 3 schematically shows the separation mechanism of a shielded hydrophobic phase consisting of hydrophobic pockets (R) enclaved by a hydrophilic network (P). Small analytes (A) can penetrate through the network and interact with the hydrophobic pockets, while larger proteins (G) are prevented from such an interaction.
FIG. 4 is a comparison of three chromatograms, A--human serum, B--propranolol (30), and C--propranolol (30) spiked human serum, as resolved upon Phase 1. N,N-bis(2'-methoxyethyl)-11-aminoundecylsilyl (see Example 1 and Table I).
Sample:
A) 20 μl injection of human serum
B) 1.0 μl injection containing 5 mg/ml propranolol in methanol
C) 2.0 μl injection containing 0.2 mg/ml of 30 in human serum
Column Dimensions: 15 cm×4.6 mm
Mobile Phase: 0.5M NH 4 OAc, adjusted to pH 6.0 with glacial acetic acid
Flow Rate: 2.0 ml/min.
Temperature: ambient
Detection: UV at 280 nm, 1.0 AUFS, ATTN 4
Chart Speed: 0.5 cm/min.
FIG. 5 is a comparison of two chromatograms, A--human serum spiked with trimethoprim (32), carbamazepine (34) and propranolol (30) and B--the same drugs in methanol, as resolved upon ω-(sulfonazide)alkylsilyl, Phase 3 (Example 3).
Sample:
A) 10 μl injection containing a 0.2 mg/ml or each drug in a 2:2:1:solution of human serum:mobile phase:methanol
B) 25 μl of 1 mg/ml of each drug in methanol
Column Dimensions: 5.0 cm×4.6 mm
Mobile Phase: 180 mM NH 4 OAc:ACN (90:10) (pH 7.0)
Flow Rate: 2.0 ml/min.
Chart Speed: 0.5 cm/min.
Temperature: ambient
Detection: UV at 280 nm, 0.5 AUFS, ATTN 2
FIG. 6 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon (10-carbomethoxydecyl)dimethylsilyl. Phase 4 (Example 4).
Sample: 10 μl injection of a 1:1 calf serum: 25 mg/ml trimethoprim (32) in 10% aqueous methanol. Chromatographic conditions as described in FIG. 5, except: 0.1 AUFS, ATTN 8.
FIG. 7 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon N,N'-bis(2-hydroxyethyl)ethylenediamino modified (10-carboxydecyl)dimethylsilyl, Phase 5. Chromatographic conditions as described in FIG. 6.
FIG. 8 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon 10 cyanodecylsilyl, Phase 6. Chromatographic conditions as described in FIG. 6.
FIG. 9 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon N-(3'-propylsulfonic acid)-11-undecylaminosilyl, Phase 7 (Example 7). Chromatographic conditions as described in FIG. 6.
FIG. 10 shows three chromatograms, A--theophylline (36), B--phenobarbital (38), and C--carbamazepine (34) of spiked calf serum at or below the therapeutic levels as resolved upon Phase 8 (Example 8).
Sample: 10 μl injection containing 10 μg/ml of each drug in calf serum
Column Dimensions: 15 cm×4.6 mm
Mobile Phase:
A--180 mM NH 4 OAc,
B and C--180 mM NH 4O Ac/ACN 95:5
Flow Rate: 2.0 cm/min.
Detection: UV at 254 nm, 0.001 AUFS, ATTN 8
Chart Speed: 5 mm/min.
FIG. 11 is a comparison of two chromatograms. A--ibuprofen (40) in human serum after Advil® ingestion and B--ibuprofen (40) standard, upon Phase 8 (Example 8).
Sample:
A--10 μl of human serum taken from a blood sample 90 minutes after ingestion of two Advil tablets
B--5 μl of ibuprofen standard (0.5 mg/ml in methanol)
Column Dimensions: 15 cm×4.6 mm
Mobile Phase: 180 mN NH 4 OAc/ACN/THF 95:5:1
Flow Rate: 2.0 ml/min.
Chart Speed: 5 mm/min.
Detection: UV at 273 nm, 0.001 AUFS, ATTN 4
FIG. 12 shows the purification of carbamazepine (34) form spiked calf serum upon Phase 8 (Example 8).
Sample:
250 μl injection of 5 μg/ml carbamazepine (34) in calf serum.
A--1.0 ml fraction was collected and 250 μl reinjected the protein containing fraction.
B--The carbamazepine (34) fraction was collected in a 2 ml fraction and 250 μl of the carbamazepine (34) fraction was reinjected (0.625 μg/ml)
Column Dimensions: 15 cm×4.6 mm
Mobile Phase:
A--180 mM NH 4 OAc
B--ACN
Gradient Profile:
______________________________________Time % A % B______________________________________0.0 100 05.0 100 05.1 85 1515.0 85 1515.1 100 020.0 100 0______________________________________
Flow rate: 2.0 ml/min.
Detection: UV at 285 nm, 0.032 AUFS
Chart Speed: 0.5 cm/min.
FIG. 13 represents, in schematic form, a cross-sectional view of a pore, 1, in the silica gel support, 2, with the hydrophilic shield, 3, and the shielded, interactive region, 4, which interacts with the small analytes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and in particular to FIG. 1, 10 represents a solvent reservoir connected to a mixer 12 which in turn is connected to a pump 14. Pump 14 is connected to a conventional injector 16, through which the sample to be analyzed is injected into the connected column 18 which contains the shielded hydrophobic phase, the subject of this invention. The column 18 is connected to a conventional chromatographic detector 20 which in turn is connected to a recorder 22. Recorder 22 graphs the chromatogram of the sample analysis. A continuous flow of solvent proceeds from the solvent reservoir 10 through the detector 20.
FIG. 2 schematically shows the interaction of a "micellar" shielded hydrophobic phase packed in the column 18. To the support (s) (usually silica gel) is bonded a hydrophobic spacer R.
The P groups form a hydrophilic and water solvated layer and the R groups a hydrophobic underlayer. The P layer prevents large bio-polymer molecules G from interacting with the underlayer R. Smaller analytes A may pass through and interact with the hydrophobic underlayer R.
FIG. 3 shows a hydrophilic network P bonding the silica support (s) to hydrophobic R group (such as alkyl, aryl, etc.).
Use of a properly designed polar hydrophilic head P excludes water soluble bio-polymers, by steric hindrance, from interacting with the underlying hydrophobic spacer R. On the other hand, small analytes are "solubilized" by the R-groups as they penetrate the hydrophilic polar layer. FIG. 2 schematically shows the chromatographic interactions of SSP with a sample consisting of bio-polymer and an analyte. The polar portion of the bonded phase will screen the bio-polymer from the hydrophobic regions of the bonded phase, resulting in its rapid elution. Under the same chromatographic conditions, the smaller analyte "solubilized" by the hydrophobic regions of the bonded phase is retained and thus separated from the larger macromolecules.
FIG. 3 describes a hydrophilic water solvated network containing enclaved hydrophobic moieties R. In a similar mechanism, the larger proteins G are screened by this network from interacting with the enclaved hydrophobic moieties R which are accessible to the smaller analytes A, resulting in fast elution of the former and retention of the latter compounds.
A large variety of high performance silica gel bonded phases have been synthesized and evaluated as SSP material for direct injection of serum, plasma, or body fluids containing drugs. These phases are set forth in the following listing as Phase 1 to Phase 8 and are illustrated by Examples and/or Figures in the drawings.
FIG. 13 represents a cross-sectional view of a pore, 1, in the silica gel support, 2, with an interactive phase, 4, bonded to the support, and a hydrophilic shield, 3, which shields the interactive phase from large, water-soluble biopolymers in the liquid being analyzed. This liquid fills the pores, 1, and carries the small, hydrophobic analytes, the large, water-soluble biopolymers, and other components. The large, water-soluble biopolymers are unable to penetrate the hydrophilic shield while the small analytes are small enough to penetrate it readily and interact with the interactive phase, producing the desired chromatographic separation.
In the drawings FIGS. 4-12 represent chromatograms. The following number designations represent peaks in the chromatogram indicating the presence of the following drugs:
(30) propranolol
(32) trimethoprim
(34) carbamazepine
(36) theophylline
(38) phenobarbital
(40) ibuprofen
SILICA GEL BONDED PHASES
Phase 1.tbd.Si(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2
Phase 2.tbd.Si(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2
Phase 3.tbd.Si(CH 2 ) n SO 2 N 3 where n=7-10
Phase 4--Si(CH 3 ) 2 (CH 3 ) 10 CO 2 CH 3
Phase 5--Si(CH 3 ) 2 (CH 2 ) 10 CON(CH 2 CH 2 OH)(CH 2 CH 2 NRCH 2 CH 2 OH) where (R)=--H and/or --CO(CH 2 ) 10 Si(CH 3 ) 2 --
Phase 6.tbd.Si(CH 2 ) 10 CN
Phase 7.tbd.Si(CH 2 ) 11 NHCH 2 CH 2 CH 2 SO 3 H
Phase 8 ##STR1## where 0≦k, l, m, n≦50, R 1 =--CONH(CH 2 ) 3 Si.tbd.(S), (S)=silica gel, Si--(S)=Si--O--Si, and R 2 , R 3 =R 1 and/or another network of the same connected through a --CO-- bond and/or H, and or alkyl, and/or carboxylate, and/or alkanamide.
Phase 9 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 N(CH 3 ) 2 in approximately equal surface concentration.
Phase 10 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 N+(CH 3 ) 3 in approximately equal surface concentration.
Phase 11 A mixed phase containing Phase 8 in which R 1 is (S).tbd.Si(CH 2 ) 3 NH(CH 2 ) 2 NHCO--, and (S).tbd.Si(CH 2 ) 3 N+(C 4 H 9 ) 3 in approximately equal surface concentration.
Phase 12 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 NHCO(CH 2 ) 2 CO 2 H in approximately equal surface concentration.
Phase 13 A mixed phase containing Phase 8 in which R 2 is ##STR2## in approximately equal surface concentration.
These phases demonstrate that the interactive region of the phase, R, may be selected from a wide variety of functionalities, including but not limited to, hydrophobic, weak-base anion exchange, strong-base anion exchange, weak-acid cation exchange and strong-acid cation exchange functionalities. Phases 1 through 8 have defined hydrophobic and hydrophilic regions and are covalently bonded to the chromatographic matrix. The bonded ligand of Phases 1-7 have a hydrophobic region R consisting of a hydrocarbon chain, --(CH 2 ) n -- where n=6 to 20, more preferably 7 to 11 and still more preferably 10 or 11, and a polar hydrophilic head P. The hydrophobic region, R, is also referred to herein as a "leash", as it both spaces the polar group from the support and tethers the polar group to the support. Phase 8 is a bonded hydrophilic polyether network enclaving hydrophobic phenyl groups bonded to the network through bis carbamate groups.
Phases 9 through 13 have regions R and P in which R is a hydrophobic group or a weak or strong cation-exchange group or a weak or strong anion-exchange group. The preferred phase contains as regions R both regions R a which are hydrophobic, and R b which are weak or strong cation-exchange groups or weak or strong anion-exchange groups or chelating groups or π--π accepting or donating groups. R a may be any of the hydrophobic groups described herein, and preferably one of the hydrophobic groups of Phases 1 through 8. The R b group may be attached to the R a group, as for example to the nitrogen in R 2 or R 3 of Phase 8, or to the silane silicon of Phase 8, in which case the R b group is shielded by the hydrophilic polymer network of the phase. Alternatively the R b group may be attached to the silica surface through an alkylsilyl, alkylaminosilyl or alkylamidosilyl group directly, and mixed-bonded with phases 1-7, in which case it will be shielded by the hydrophilic groups of neighboring hydrophobic leash-hydrophilic head micelles. The R b group in Phase 9 is --N(CH 3 ) 2 , a weakly basic anion exchanger; in Phase 10 it is --N + (CH 3 ) 3 , a strongly basic anion exchanger; in Phase 11 it is --N + (C 4 H 9 ) 3 , another strongly basic anion exchanger; in Phase 12 it is --CO 2 H, a weakly acidic cation exchanger; and in Phase 13 it is --SO 3 H, a strongly acidic cation exchanger.
These phases also demonstrate that the polar head P may be selected from a wide variety of functionalities including, but not limited to: amines, amides, esters, ethers, alcohols, azides, carboxylic acids, cyano groups, thiols, diols, amino acids, nitriles, sulfonic acids, ureas, and the like, or a combination of such. All of these phases have shown retention of small drug analytes while excluding serum proteins when tested with drug containing serum. FIGS. 4-12 illustrate various chromatographic separations as carried out with different SSP supports. In a typical chromatographic separation on an SSP, the bio-polymer will elute completely, or almost completely, in the void volume, while the analyte elutes later.
The SSP supports can be simply slurry packed into standard liquid chromatography columns and used with standard HPLC equipment. Such a combination allows for the direct, on-line resolution of small analytes from a complex bio-polymer matrix in a single and simple chromatographic step. The SSP supports solve, in a new and novel way, the problem of direct, on-line analysis of analytes in bio-matrices such as serum or plasma. An example for commercial applications of this invention is the direct analysis of drugs, metabolites, etc., from serum, plasma, saliva, urine, or other body fluids as is often performed in the pharmaceutical industry, clinical and drug testing laboratories, toxicology studies, etc.
The following examples are intended to illustrate the invention, and are not to limit it except as limited by the claims. All percentages herein are by weight unless otherwise indicated, and all reagents are of good commercial quality unless otherwise indicated.
EXAMPLE 1
N,N-bis(2'-methoxyethyl)-11-aminoundecylsilyl, Phase 1.tbd.Si(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2 N,N-bis(2'-Methoxyethyl)-11-(triethoxysilyl)undecylamine, (II)
To a solution of 16.8 g 10-undecenal in 25 ml methylene chloride, crystals of di-μ-chlorodichlorobis(ethylene)-diplatinum (II) were added and the solution heated to 40°-45° C. A solution of 16.4 g triethoxysilane in 25 ml methylene chloride was added dropwise over a period of 90 minutes. After reagent addition was completed, the rection mixture was heated for an additional 30 minutes. The mixture was fractionated and the product, 11-triethoxysilylundecanal (I) was obtained at 65° C. at 0.2 mm Hg at a 30% yield.
A solution of 6.0 g of I and 3.0 g of bis(2-methoxyethyl)amine in 100 ml absolute ethanol containing 0.25 g 10% Pd/C was hydrogenated in a Parr instrument for 90 minutes at room temperature. The mixture was filtered and the alcohol removed under reduced pressure. The residue was purified by column chromatography using 100 g dry silica gel, starting with toluene and increasing the polarity with ethyl acetate. The product, (II), eluted at 50% and 100% ethyl acetate fractions.
BONDING
A solution of (II) in 15 ml toluene was added to 4.0 g of silica gel (5-μm particle size, 100 m 2 /g surface area, 12.5 nm average pore diameter) placed in a 50 ml glass ampule. The mixture was slurried to homogeneity and the solvent was removed under vacuum while the slurry was continuously agitated. Ammonia (gaseous) was added to the evacuated mixture, then the ampule was sealed and heated at 100° C. overnight. The mixture was thoroughly washed with methylene chloride, then methanol, and then dried. From the elemental analysis: C--6.72% (silica blank C--0.41%), a ligand coverage of 3.13 μmol/m 2 was calculated for C 17 H 37 NO 3 Si, (═Si(OH)--(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2 ).
A 15 cm×4.6 mm column was slurry packed at pressure above 52 MegaPascals. Human serum spiked with the drugs listed in Table I was directly injected through injector 16 onto column 20 containing phase 1. The column resolved the drugs from the human serum components (see Table I). FIG. 4 shows the chromatographic resolution of propranolol and other drugs from spiked human serum using the procedures of Example 1.
TABLE I______________________________________RETENTION TIMES FOR DRUGS FROM SPIKEDHUMAN SERUM ON PHASE 1Drug Retention Time (min.) Mobile Phase______________________________________Theophylline 1.78 1Propranolol 5.00 1Propranolol 2.52 2Quinidine 1.97(a) 2Carbamazepine 33.58 1Carbamazepine 12.96 2Desipramine 4.25 2Column Dimensions: 15 cm × 4.6 mmFlow Rate: 2.0 ml/min.______________________________________ 1. 0.5M NH.sub.4 OAc aqueous solution adjusted to pH 6.0 with glacial acetic acid 2. 0.5M NH.sub.4 OAc pH 5.0 adjusted with H.sub.3 PO.sub.4 : 2propanol: THF 500:25:1 (a) Not completely resolved from minor serum components
EXAMPLE 2
N,N-bis(2'-methoxyethyl)-11-silylundecanamide, Phase 2 .tbd.Si(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2
The material was prepared from N-hydroxysuccinimido 11-(triethoxysilyl)undecanoate which was treated with an equivalent of bis-(2-methoxyethyl)amine in methylene chloride in the presence of an equivalent of triethylamine. The product, N,N-bis-(2'-methoxyethyl)-11-(triethoxysilyl)undecanamide (III), was purified by column chromatography on a ten-fold w/w silica gel column, starting with toluene and increasing polarity with ethyl acetate. The product, an oil, eluted at 20% ethylene acetate with approximately 80% yield.
Bonding as for (II) Example 1 using 6.0 g of the same silica and impregnating with 1.65 g of (III) in 20 ml hexane yielded the N,N-bis-(2'-methoxyethyl)-11-undecanamide, Phase 2.
Elemental analysis: C--3.64, H--1.13, and N--0.40%. From the carbon percentage a coverage of 3.14 μmol/m 2 was calculated for C 17 H 35 --NO 4 Si (Si(OH)--(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2 ) ligand. A 15 cm×4.6 mm column was slurry packed at pressures above 52 MegaPascals. Human serum spiked with the drugs listed in Table II was directly injected through injector 16 onto column 20 containing phase 2. The column retained the drugs as listed in Table II.
TABLE II______________________________________RETENTION TIMES FOR DRUGS ON PHASE 1Drug Retention Time (min.) Mobile Phase______________________________________Caffeine 1.11 1Acetaminophen 1.69 1Propranolol 18.01 1______________________________________ (1) 0.05M ammonium acetate, 0.1M potassium chloride (pH 3.0)/MeOH 80:20
EXAMPLE 3
ω-(sulfonazido)alkylsilyl, Phase 3 .tbd.Si(CH 2 ) n SO 2 N 3 n=7-10
To 10 g of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a 100 ml round bottom flask were added 10 ml of AZ-CUP MC Azidosilane reagent (Hercules, Inc., Wilmington, Del.), 25 ml of methylene chloride and 25 ml of toluene. The mixture was refluxed for eight hours, cooled, filtered, washed with 3×100 ml of methylene chloride, followed by 3×100 ml of methanol, and oven dried at 80° C. Elemental analysis: C--8.92, H--1.82, N--1.07, and S--0.58%. The resultant bonded phase was slurring packed at pressures above 34 MegaPascals into a 5 cm×4.6 mm column. Human serum spiked with the drugs listed in Table III were directly injected through injector 16, onto column 20, containing phase 3. FIG. 5 shows the chromatographic resolution of trimethoprim (32), carbamazepine (34), and propranolol (30) from the spiked human serum sample.
Table III indicates the retention time for other drugs using the procedure of Example 3.
TABLE III______________________________________RETENTION TIME FOR DRUGS AND TEST PROBESFROM SPIKED HUMAN SERUM ON THE SULFAZIDEPHASE 3Test Compound Retention Time (min.)______________________________________Uracil 0.37Theophylline 0.54Caffeine 0.71Acetaminophen 0.54Trimethoprim (32) 3.34Carbamazepine (34) 4.50Codeine 2.92Hydrochlorothiazide 1.16Procainamide 2.04Propranolol (30) 13.52______________________________________
Column Dimensions: 5 cm×4.6 mm
Mobile Phase: 180 nM NH 4 OAc:ACN (90:10) (pH 7.0)
Flow Rate: 2.0 ml/min.
EXAMPLE 4
(10-carbomethoxydecyl)dimethylsilyl, Phase 4 --Si(CH 3 ) 2 (CH 2 ) 10 CO 2 CH 3
To 5.0 g of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a round bottom flask was added 2.0 ml of (10-carboxymethoxydecyl)dimethylchlorosilane dissolved in 50 ml of dried toluene. The mixture was refluxed for 14 hours, cooled, filtered, washed with 3×100 ml of toluene followed by 3.×100 ml of methanol, and dried. Elemental analysis: C--5.66, and H--1.22%. A bonded phase coverage of 2.40 μmol/m 2 was calculated for C 14 H 29 O 2 Si ligand. A 5 cm×4.6 column was slurry packed with this material at pressures above 41 MegaPascals. The resultant column containing phase 4 was capable of baseline resolution of trimethoprim from calf serum (FIG. 6) directly injected through injector 16.
EXAMPLE 5
N,N'-bis(2-hydroxyethyl)ethylenediamino modified 11-dimethylsilylundecanoic acid (IV), Phase 5 --Si(CH 3 ) 2 (CH 2 ) 10 CON(CH 2 CH 2 OH(CH 2 CH 2 NRCH 2 OH) R=H and/or CO(CH 2 ) 10 Si(CH 3 ) 2 --
A 3.8 g sample of phase 4 was hydrolyzed with 50 ml 1:1 methanol:water mix adjusted to pH 2.85 using glacial acetic acid. The mixture was shaken overnight, filtered and washed with 3×50 ml of 1:1 methanol:water, followed by 3×50 ml of methanol, and dried to yield (IV). A 3.6 g of (IV) was placed in a flask with 1.0 g of N,N'-bis(2-hydroxyethyl)ethylene diamine and 1.1 g of EEDQ (1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline) dissolved in 40 ml of dry THF. The mixture was shaken for six hours at room temperature. The mixture was filtered, washed with 3×100 ml of dry THF, followed by 3×100 ml of methanol, and dried. Elemental analysis:C--9.13, H--1.71, and N--1.57%. From the carbon percentage a coverage of 3.07 μmol/m 2 or 2.06 μmol/m 2 was calculated for (R=H) C 19 H 41 N 2 O 3 Si or for (R=CO(CH 2 ) 10 Si(CH 3 ) 2 --) C 32 N 66 N 2 O 4 Si 2 , respectively. A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resulting column containing Phase 5 gave a baseline resolution of trimethoprim from calf serum (FIG. 7) when injected directly through injector 16.
EXAMPLE 6
10-cyanodecylsilyl, Phase 6 .tbd.Si(CH 2 ) 10 CN
To 10 g of oven dried SULPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a 250 ml round bottom flask was added 2.5 ml of 10-cyanodecyltrichlorosilane and 75 ml of toluene. The mixture was refluxed for five hours and then 1.5 ml of trimethylchlorosilane was added and the mixture was refluxed an additional hour. The mixture was cooled, filtered, and washed with 3×100 ml of toluene followed by 3×100 ml of methanol, and dried.
Elemental Analysis: C--8.38, H--1.56, and N--0.98%. A bonded phase coverage of 4.03 μmol/m 2 was calculated for a C 11 H 22 NOSi ligand, (.tbd.Si(OH)(CH 2 )CN).
A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resultant column containing Phase 6 gave a baseline resolution of trimethoprim from calf serum (FIG. 8) when injected directly through injector 16.
EXAMPLE 7
N-(3'-propylsulfonic acid)-11-undecylaminosilyl, Phase 7 .tbd.Si--(CH 2 ) 11 NHCH 2 CH 2 CH 2 SO 3 H
Preparation of 11-(undecylamine)trimethoxysilane
According to Freifelder (J. Am. Chem. Soc. 82 (1960) 2386) by hydrogenating 10-(trimethoxysilyl)cyanodecane in the presence of 5% Rh/alumina in 12% methanolic ammonia solution instead of ethanolic solution. The product was fractionated b.p. 145°-147° C. at 0.25 mm Hg, 50% yield.
11-Aminoundecylsilyl Phase:
5.3 g of (11-undecylamine)trimethoxysilane was dissolved in 75 ml toluene and added to 20.4 g. of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size). The mixture was refluxed for seven hours, cooled, filtered, washed with 3.0×50 ml of toluene, followed by 3×50 ml of methanol, and dried.
Elemental analysis: C--6.68, H--1.38, N--0.54%. From the carbon percentage, a coverage of 3.38 μmol/m 2 was calculated for a C 12 H 27 NOSi ligand.
Phase 7 Preparation: to 5.0 g of the 11-aminoundecylsilyl phase dried at 65° C. under high vacuum was added 1.2 g of 1,3-propane sultone dissolved in 35 ml of methylene chloride, followed by 75 ml of methylene chloride containing 250 μl of pyridine. The mixture was shaken at room temperature for several minutes and then refluxed for three hours. The mixture was filtered, washed with 3×100 ml of methylene chloride, followed by 3×100 ml of methanol, and dried. Elemental analysis: C--8.58, H--1.60, N--1.40, and S--0.83%. From the carbon percentage, a coverage of 3.41 μmol/m 2 was calculated for a C 15 H 33 O 3 SSi ligand. A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resultant column containing Phase 7 gave a baseline resolution of trimethoprim from calf serum (FIG. 9) when injected directly through injector 16.
EXAMPLE 8
Urethane-modified 3-propylamine, Phase 8
.tbd.SiCH.sub.2 CH.sub.2 CH.sub.2 NHCONHR
where R=branched polyethylene oxide with terminal hydroxyl groups substituted with tolydiisocyanate: ##STR3## where 0≦k, l, m, n≦50, R 1 =.tbd.SiCH 2 CH 2 CH 2 NHCONHR, (S)=silica gel, Si--(S)=Si--O--Si, and R 2 , R 3 =R 1 and/or another network of the same connected through a --CO-- bond and/or H, and or alkyl, and/or carboxylate, and/or alkanamide.
To 30 g of dry SUPELCOSIL silica (5-μm particle size, 10-nm pore size) 20 g of 3-aminopropyltrimethoxysilane and 300 ml of toluene were added. The suspension was heated to reflux for 16 hours, and the reaction mixture was filtered and washed with 300 ml of toluene followed by 300 ml of methanol and dried at 60° C. under nitrogen for 10 hours.
To 600 ml of toluene in a 1000 ml round bottom flask was added 5.0 g of Hypol FHP 2000 polymer (W. R. Grace, Co., Lexington, Mass.). The polymer was completely dissolved by shaking and sonicating. To the solution 12.5 g of the 3-aminopropyltrimethoxysilane-bonded silica from the step above was added. The suspension was refluxed for three hours. To the mixture was added 0.2 g of 1,4-diazabicyclo-(2,2,2)octane dissolved in 10 ml of toluene, and the mixture was refluxed for an additional three hours. The "hot" mixture was filtered, washed with toluene, methylene chloride and methanol, and oven dried. Elemental analysis: C--10.41, H--1.66, and N--1.30%.
A 15 cm×4.6 mm column was slurry packed at pressures above 52 MegaPascals. The column resolved various drugs from calf and human sera. FIG. 10 shows carbamazepine-, phenobarbital- and theophylline-spiked human serum samples as resolved on a column containing Phase 8 by directly injecting the spiked samples through injector 16. FIG. 11 shows the resolution of ingested ibuprofen from human serum. FIG. 12 shows the trace enrichment/purification by a step-wise elution of a carbamazepine-spiked calf serum and the chromatographic results of the collected protein and drug containing fractions. This evaluation demonstrates the application of the packing material for trace enrichment, which could be applied in solid phase extraction of small volumes up to large scale industrial levels.
EXAMPLE 9
R=--N(CH 3 ) 2 , Phase 9
To 7.12 g of SUPELCOSIL™DB silica (5μm particle size, 10 nm pore size) previously conditioned at 85% humidity (allowing to equilibrate over a saturated aqueous solution of lithium chloride) were added 5.6 mmole (1.16 g) of N,N-dimethyl-3-aminopropyltrimethoxysilane, 5.6 mmole (1.0 g) 3-aminopropyltrimethoxysilane and 100 ml toluene. The mixture was suspended and refluxed for 4 hours. The mixture was filtered, and the solid material was washed with 200 ml toluene, then 200 ml methylene chloride, and finally 200 ml methanol. The solid product was dried at 60° C. under nitrogen for four hours followed by two hours at high vacuum. To the dried solid product a solution of 2.8 g Hypol FHP 2000 polymer (W. R. Grace Company, Lexington, Mass. in 100 ml of dry toluene was added. The mixture was suspended and refluxed for one hour; 1.0 ml of hexylamine was added and suspended, and the mixture was refluxed for one additional hour. The solid product was filtered hot and washed with 200 ml each of toluene, methylene chloride and methanol. The solid product was dried at 60° C. under nitrogen for four hours. To the solid product 50 ml of dry pyridine and 4.0 ml of acetic anhydride were added. The mixture was agitated for 10 hours, then filtered and washed with 100 ml toluene, 200 ml methylene chloride and 300 ml methanol. The solid product was dried at 60° C. under nitrogen for four hours.
Elemental analysis: C--14.95%; H--2.33%; N--1.99%.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 9. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table IV, below.
EXAMPLE 10
R=--N + (CH 3 ) 3 , Phase 10
Phase 10 was prepared according to the procedure of Example 9, above, except that 3 μmole per square meter of silica surface of a 50% methanolic solution of N-(3-trimethoxysilylpropyl)trimethylammonium chloride was used in place of the N,N-dimethyl-3-aminopropyltrimethoxysilane, and 3 μmol per square meter of silica surface of the 3-aminopropyltrimethoxysilane was used.
Elemental analysis: C--15.83% and N--1.92%.
A 4.6-mm×15-column was slurry packed at 59 MegaPascals with Phase 10. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table IV, below.
EXAMPLE 11
R=--N + (C 4 H 9 ) 3 , Phase 11
Phase 11 was prepared according to the procedure of Example 9, except that 3 μmole per square meter of silica surface of a 50% methanolic solution of N-(3-trimethoxysilylpropyl)tributylammonium bromide and 3 μmole per square meter of silica surface of N-(2-aminoethyl)-3-aminopropyltrimethylsilane were substituted for the N,N-dimethyl-3-aminopropyltrimethoxysilane and 3-aminopropyltrimethoxysilane of Example 9.
Elemental analysis: C--15.85% and N--2.40%
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 11. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicyclic acid and benzoic acid are shown in Table IV, below.
TABLE IV______________________________________CAPACITY FACTOR RESULTS FORCHROMATOGRAPHIC SEPARATION WITHBASIC MODIFIED PHASE 8SeparatedComponent Phase 8 Phase 9 Phase 10 Phase 11______________________________________Chloramphenicol 2.54 4.04 5.61 5.20Salicylic Acid 2.05 5.20 10.20 23.19Benzoic Acid 1.16 2.19 3.66 4.44Total Serum 11.5 10.8 11.6 12.0Protein Area,(million counts)______________________________________
Chromatographic Conditions
Mobile Phase: 95% 180 mM NH4OAc (aq) pH=7.0/5% AcN
Flow: 2.0 ml/min
Injection Volume: 10 μl
Concentration and Detection:
Chloramphenicol, 10 μg/ml, 278 nm, 0.016 AUFS
Salicylic Acid, 25 μg/ml, 280 nm, 0.008 AUFS
Benzoic Acid, 10 μg/ml, 254 nm, 0.016 AUFS or 0.032 AUFS
Serum, neat, 254 nm, 0.016 AUFS
Temperature: Ambient.
NOTE--The Capacity factor, C i , is defined as ##EQU1## where V i is the elution volume of compound i and V o is the elution volume of an unretained compound (V o is also termed the void volume).
EXAMPLE 12
R=--CO 2 H, Phase 12
Phase 12 was prepared according to the procedure of Example 9, except that only 20 μmole per square meter of silica surface of the 3-aminopropyltrimethoxysilane and no other aminosilane was used; subsequent to the addition of the pyridine but prior to the addition of the acetic anhydride, 0.15 g/g of silica of succinic anhydride was added and the mixture was agitated for 22 hours; and in the final washing of the solid product the first rinse was with water, followed by 50% aqueous methanol and finally methanol.
Elemental analysis: C--16.69%, H--2.48%, and N--2.23%.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 12. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table V, below.
EXAMPLE 13
R=--SO 3 H, Phase 13
Phase 13 was prepared according to the procedure of Example 12, except that the reaction mixture was cooled to room temperature and instead of the hexylamine, a solution of 1.5 g hexamethylenediamine in 50 ml of toluene for each 10 g of silica gel was added and the mixture was agitated for three hours. In addition, prior to adding the acetic anhydride the solid product is dried under high vacuum at 60° C. for two hours; 4 μmole per square meter of silica surface of 3-fluorosulfonylbenzenesulfonyl chloride was substituted for the succinic anhydride; and following the final washing step the solid product was dried under high vacuum at 60° C. for two hours. A calculated amount of 3 μmole per gram of silica, based on the pretreatment weight of silica used in this example, of tetrabutylammonium hydroxide in a 40% aqueous solution was evaporated to dryness under vacuum for three hours at ambient temperature, dissolved in 4 ml/g of silica of dry pyridine, and added to the silica. The mixture was agitated at room temperature for 20 hours, filtered and washed thoroughly with 1:9 acetonitrile:water containing 180 mmole ammonium acetate, followed by washing with water and then methanol. The solid product was dried at 60° C. under nitrogen for four hours.
Elemental analysis:
Prior to final treatment step- C--16.14%, H--2.48%, N--2.35%, S--0.75% and F--0.20%
Final product- C--16.19%, H--2.48%, N--1.83%, S--0.55% and F--0.050%.
Despite the presence of fluoride in the final product, the material that was almost completely inactive to ion exchange prior to the tetrabutylammonium hydroxide treatment became an active ion-exchange material following this treatment.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 13. The operating conditions and results of chromatographically separating a mixture of chloramphenicol, salicylic acid and benzoic acid are shown in Table V, below.
TABLE V______________________________________CAPACITY FACTOR RESULTS FORCHROMATOGRAPHIC SEPARATION WITHACID-MODIFIED PHASE 8Separated Phase 8 Phase 12 Phase 13Component pH 7 pH 4 pH 7 pH 4 pH 7 pH 4______________________________________Chloramiphenicol 2.54 2.25 3.79 3.16 4.06 3.53Trimethoprim 2.56 0.30 4.83 0.25 4.02 2.21Propranolol 2.94 0.85 8.40 0.76 9.80 6.00Total Serum 11.5 11.1 11.7 12.0 11.4 10.0Protein Area(million counts)______________________________________
Chromatographic Conditions
Mobile Phase:
for pH 7--95% 180 mM NH 4 OAc (aq) pH=7.0/5% AcN
for pH 4--95% 90 mM NH 4 OAc (aq) pH=4.0/5% AcN
Flow: 2.0 ml/min
Injection Volume: 10 μl
Concentration and Detection:
Chloramphenicol, 10 μg/ml, 278 nm, 0.016 AUFS
Trimethoprim, 25 μg/ml, 254 nm, 0.016 AUFS
Propranolol, 25 μg/ml, 254 nm, 0.016 AUFS
Serum, neat, 254 nm, 0.016 AUFS
Temperature: Ambient.
NOTE--Chloramphenicol, trimethoprim and propranolol values were determined in a serum matrix.
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Novel packing materials are provided for liquid chromatography and/or solid phase extraction columns which will allow direct injection of biological fluids. These packing materials have a hydrophilic exterior layer and a hydrophobic, charged or otherwise selective portion that forms an underlayer or is embedded in the hydrophilic layer. During a chromatographic process large water soluble biopolymers will be in contact with the hydrophilic outer layer and be shielded from interacting with the underlayer or embedded portion and elute unretained. Small analytes, on the other hand, can be fully partitioned throughout the exterior and interior layers and are retained by hydrophobic or electrostatic interactions. Using such packings the direct analyses of plasma or serum for drug analysis is demonstrated.
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FIELD OF THE INVENTION
[0001] The invention concerns the area of materials that are initially soft and flexible for refractory use. More particularly, it concerns materials containing precursor elements of a ceramic to which they convert during their rise in temperature, acquiring their refractoriness.
PRIOR ART—PROBLEM RAISED
[0002] Soft refractory materials are used in numerous areas such as the steel or aluminium industries. They are used in the form of paper, cloth, rope.
[0003] The production of soft refractory materials involves the use of refractory fibres which are their chief constituent. Asbestos was used on industrial level up until its interdiction connected with its proven hazardousness. These fibres were then replaced by refractory ceramic fibres which are amorphous silicates generally obtained by the fusion of alumina and silica. The use of these fibres in soft refractory materials underwent a major increase on account of their insulating and refractory properties, providing substantial gains in terms of energy consumption in industrial processes requiring high temperatures. Nonetheless, some doubts remained as to their harmlessness vis-à-vis humans, in particular in the event of prolonged exposure. Data collected in Europe since 1991 and research on animals have shown that the risk of onset of illnesses induced by prolonged exposure to refractory fibres is a real risk. Consequently, on Nov. 10, 1997, the European Commission classified refractory ceramic fibres as a hazardous product under category II (substances which are to be considered potentially carcinogenic for man). Henceforth, skull labelling is required and full information on the risks for human health. This classification does not imply the prohibited use of refractory fibres in industrial environments but some restrictions and regulations have already been introduced into the legislation of member states.
[0004] The manufacturers of refractory ceramic fibres are working hard to find replacement solutions and some products are emerging such as bio-soluble fibres containing dolomite, but the temperature at which these materials can be used remains limited. Other materials such as high purity silica, cordierite, mullite-zirconium or high purity aluminas are being tested, but at the present time their form and cost prohibit their use for most applications.
[0005] The problem therefore remains, in respect of soft refractory materials, of finding materials which do not contain refractory ceramic fibres, have good insulating and refractory properties and whose cost is economically acceptable in an industrial environment.
DESCRIPTION OF THE INVENTION
[0006] The first subject of the invention is a soft paste able to fulfil the same functions as fibre-based products currently used as precursors for soft refractories. The paste of the invention is characterized in that it contains an elastomer polymer, a silylation agent (creator of Si—O bonds), a mixture of alumina and alumina hydrate and optionally a plasticizer. During its rise in temperature, the organic part is removed and leaves behind a refractory solid chiefly made up of alumina.
[0007] The second subject of the invention is a method for manufacturing the paste of the invention comprising the following steps:
[0008] a) Preheating a mixer to a temperature of between 40 and 60° C., preferably between 50° and 60° C.
[0009] b) Placing in the mixer the elastomer polymer, silylation agent, alumina and alumina hydrate.
[0010] c) Mixing the contents until a homogeneous paste is obtained.
[0011] The third subject of the invention is a soft, refractory precursor having various forms: granules, rods, rolls, sheets, strips.
[0012] The fourth subject of the invention is the use of the refractory precursor paste as an outer sheath or packing for an electric cable or as a fireproof seal or panel.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The first subject of the invention is a precursor paste for a refractory material characterised in that it contains an elastomer polymer containing firstly a mixture of alumina and alumina hydrate and secondly a silylation agent.
[0014] The silylation agent is an agent which sets up Si—O bonds; as an example the following may be cited: trialkoxysilanes, whether hydrolysed or not, silsesquioxanes, silazanes.
[0015] The alumina entering into the composition of the paste is a ground alumina. This alumina has a typical particle size of 05 to 10 microns, corresponding to a specific surface area of between 0.5 and 15 m 2 /g.
[0016] The alumina hydrate entering into the composition has a typical particle size of between 3 and 20 microns, preferably between 5 and 15 microns. Alumina hydrate is well known in the area of plastic materials in which it is used as a component on account of its fireproofing qualities; it is an indispensable component of the paste in order to prevent combustion of the polymer during the first temperature rise and to enable ceramisation. It may be replaced by magnesium hydroxide which is also used for fireproofing some polymers.
[0017] It is known that the silylation agent creates a set of Al—O—Si bonds. The applicant has found that these bonds rigidify the paste as soon as the polymer reaches temperatures at which it is likely to flow.
[0018] This rigidifying often occurs over time at storage temperatures, which must be avoided to solve the problem raised.
[0019] The applicant has found that this problem does not arise if a trialkoxy silane is used of epoxy type and more especially (3 glycidoxy propyl) trimethoxysilane previously hydrolysed in silanol, or else a silane of amino type and more particularly non-hydrolysed N-aminoethyl-3 amonopropyltrimethoxysilane. One possible alternative is the use of (poly)methylsilsesquioxane or polysilazane in the non hydrolysed state.
[0020] It is also found that some well known silylation agents are not suitable. (4-aminopropyl)triethoxysilane for example does not give a solid product at high temperature whereas (mercaptoethyl) trimethoxysilane and poly(phenyl-propylsilsesquioxane) causes early, rapid rigidifying of the soft product at room temperature.
[0021] Elastomer polymer belongs to the ethylene propylene diene family. The applicant achieved very good results with ethylene propylene diene monomer, better known under the initials EPDM.
[0022] To facilitate manufacture of the paste, it is advisable to add a plasticizer to proportions in the order of 0 to 10% of the total weight of the paste.
[0023] The proportions of the different components differ according to the subsequent use of the paste. A typical range for most usual applications of soft refractories is:
Alumina: 30 to 40% by weight Alumina hydrate or 30 to 40% by weight magnesium hydroxide Silylation agent 5 to 15% by weight Polymer 10 to 20% by weight Plasticizer 0 to 10% by weight
[0024] This paste can be reinforced with fibreglass.
[0025] The second subject of the invention is a process for manufacturing a precursor paste for a refractory material characterized in that it comprises the following steps:
[0026] a) Preparation of the Silylating Agent by Hydrolysis
[0027] This preparation of the silylating agent by hydrolysis may be an optional step in the process.
[0028] The preparation of the silylation agent (when necessary) is conducted in a separate, stirred container to which water is added whose pH is previously adjusted to the value specifically recommended for performing hydrolysis of the agent to be used. The proportions of the water must be greater than stoichiometric proportions. The ratio of the number of moles of water to the number of moles of silylation agent typically lies between 4 and 7. It is advisable for hydrolysis to be complete. The stirring time is a few minutes. The operation has been completed when the solution becomes clear.
[0029] b) Preheating of a Mixer
[0030] Preheating of the mixer is conducted up to a temperature of between 40 and 60° C., preferably between 40° C. and 50° C. If preheating is insufficient, the polymer will not reach sufficient viscosity. If the mixer temperature is too high, the silylation agent reacts too quickly and causes early rigidifying of the paste.
[0031] c) Placing the Polymer in the Mixer with the Silylation Agent, Alumina and the Alumina Hydrate or Magnesium Hydroxide
[0032] It is sometimes preferable to add a plasticizer to proportions in the order of 0 to 10% of the total weight of the paste. This additive also acts as lubricating agent.
[0033] d) Mixing the Mixer Contents Until a homogeneous Paste is Obtained
[0034] The stirring speed of the mixer may be adapted as the contents are added. Operating time depends upon the desired viscosity of the paste. This viscosity is permanently measured by the couple. The operation is halted when the couple reaches a set threshold.
[0035] Self-heating of the mixer contents does not generally exceed 85° C., but for security it is advisable to make provision for a mixer cooling system which is triggered when there is risk of exceeding 85° C.
[0036] The third subject of the invention concerns a soft material obtained from the refractory precursor paste according to the invention.
[0037] Under a first form, the paste can be extruded in the form of a yarn or roll of any section. Products obtained in this form have diameters or equivalent diameters generally varying between 4 and 25 mm. These products are conventionally used as seals for oven doors, static oven sealants, casting mould seals in metallurgy, etc.
[0038] Under a second form, the paste can be rolled or pressed into sheets or soft strips whose thickness generally varies from a few mm to a few cm. These sheets or strips may be used for inner linings and partitions of industrial furnaces. The application of these linings is facilitated by the flexibility of the material and the ease with which it can be precision cut using ordinary instruments.
[0039] Under a third form, the paste can be fragmented into granules. This form can be used to feed machines for subsequent processing of the paste, extruding machines for example.
[0040] The fourth subject of the invention concerns the end use of the precursor paste for refractories in various applications such as seals and heat insulators for high temperature use and more particularly:
[0041] outer sheath or packing for electric cables
[0042] fireproof seals or fireproof panels
[0043] As it can be extruded, this paste can be used as a component for insulated cables, either as packing or as an outer sheath.
[0044] In this application, the paste of the invention offers major advantages in the event of a substantial, untimely rise in temperature: its capacity to rigidify and become refractory and insulating while resisting ignition and with continued non-release of harmful gases (through the use of alumina hydrate as opposed to the use of halogen derivatives) it is possible for an electric cable to maintain its properties of use (transmission of electricity) under extreme conditions such as fire for example.
[0045] In the form of a fireproof seal or fireproof panel, the same mechanism of rigidifying and conversion into a refractory material means that the paste can advantageously replace soft materials made from refractory ceramic fibres conventionally used for these applications.
EXAMPLES OF EMBODIMENT
Example 1
[0046] A twin-rotor mixer of Banbury type was used fitted with couple follow-up and a heating system. The mixer was preheated to 60° C. and the stirring speed set at 80 rpm. First 40 g alumina powder, having a median diameter of 0.5 micron (quality P 172SB—PECHINEY), were mixed with 40 g of alumina hydrate powder, median diameter of 10 microns (quality SH 100). This first mixing step lasted 10 minutes. Subsequently, 8.8 g (N-aminoethyl-3)aminopropyltrimethoxysilane was added, not hydrolysed previously, and mixing was continued for ten minutes checking that the powder was impregnated in homogeneous manner corresponding to a stabilised mixing couple value. Finally, 16g EPDM in piece form were added (ethylene propylene diene monomer—Keltan 778 Z obtained from DSM), and 6.4 g plasticizer (Primsol oil 352—ESSO). Mixing was continued for 20 minutes until a threshold couple measurement was reached. The final temperature was 80° C.
[0047] The paste obtained was rolled directly and fragmented at room temperature so that it could be added to a twin-screw extruding machine. The temperature was set at between 80 and 90° C. The material was extruded in the form of soft rods 6 mm in diameter and 1.8 m long.
[0048] The product obtained was folded over without incurring any damage. A rise in temperature, under air, (300° C./hour) gave a rigid product, with no creep, with no substantial variation in size relative to the initial soft rod and with no flame generation. The product was then subjected to twenty consecutive heat cycles of between 800 and 12000C. The material remained stable in appearance. Its measured mechanical resistance (three-point bending) was greater than 1 MPa.
Example 2
[0049] Another example consists of using an open type roller mixer to prepare the paste, of the type typically used in elastomer industries.
[0050] In this case, the silylation agent is a trialkoxysilane previously hydrolysed in silanol.
[0051] 107 g of this silylation agent were laboratory prepared by mixing 70 g of (3-glycidoxypropol) trimethoxysilane and 37 g of water. Hydrolysis was performed at room temperature using water previously acidified to a pH of 3.5 using acetic acid. At the start of the operation, the solution was cloudy and then became clear, a sign that hydrolysis was completed.
[0052] The silanol obtained was immediately mixed with the mineral components made up of 500 g alumina powder, median diameter 0.5 micron (quality P 172 SB—PECHINEY) and 500 g alumina hydrate, median diameter 10 microns (quality SH 100—PECHINEY).
[0053] 200 g EPDM (Keltan 778 Z—DSM) were mixed in the roller mixer and the above described components were gradually added over a time of approximately 10 min. The rollers were adjusted to a temperature of 65° C. It was not necessary to add a plasticizer to obtain a soft, homogeneous paste. Part of this paste was placed in strip form in a mono-screw extruding machine with low compression force so as to produce a rod having a diameter of 12 mm over a length of 2.5 metres. The remainder of the paste was rolled in sheet form to a thickness of 5 mm. Similar heat treatment to the treatment described in example 1 was applied and gave similar results for both sample forms. The sample in sheet form was cut into 10×10 cm squares and left to rest on its corners: no warping was seen to occur.
Example 3
[0054] In this example, the silylation agent used belongs to the silsesquioxane family. As in example 1, a twin-rotor mixer of Banbury type was used, fitted with couple follow-up and a preheating system. The mixer was preheated to 60° C. and the stirring speed set at 80 rpm. First 40 g alumina power, median diameter 0.5 micron (quality P 172 SB—PECHINEY) were mixed with 40 g of alumina hydrate power, median diameter 10 microns (quality SH 100). This first mixing step lasted 10 minutes. Subsequently, 8 g polymethylsilsesquioxane were then added in the form of a 600 g/litre solution in toluene, mixed again for ten minutes and it was checked that the powder was impregnated in homogeneous manner, indicating a stabilised mixing couple value. Finally 16 g EPDM in piece form were added (ethylene propylene diene monomer—reference Keltan 778 Z from DSM).
[0055] The use of a plasticizing additive was not necessary. Mixing was continued for 10 minutes until a couple threshold level was reached. The final temperature was 78° C.
[0056] The paste obtained was directly rolled then, at room temperature was cut into fragments so that it could be placed in a twin-screw extruding machine. The temperature was set at between 80 and 90° C. The material was extruded in the form a soft rod 6 mm in diameter and 1.6 m in length. The results obtained with heat treatment compared with those given in example 1.
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The invention concerns fibre-free precursor pastes of refractory material characterised in that they contain an elastomeric polymer filled with alumina and alumina hydrate and a silylating agent, generating Si—O bonds. The invention also concerns the method for making said paste and the material and the use thereof.
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RELATED APPLICATION INFORMATION
This application claims benefit of U.S. Provisional Application No. 60/293,390, filed May 23, 2001, which is hereby incorporated by reference.
TECHNICAL FIELD
The generally invention relates to internal combustion engines and, more particularly, to a piston driven rotary-type internal combustion engine.
BACKGROUND OF THE INVENTION
Engine designers are constantly endeavoring to design engines that maximize fuel efficiency while minimizing polluting byproducts of the combustion process. Fuel consumption has both a direct effect on the output of pollutants and the expense for the fuel used. Moreover, increasing the fuel efficiency of machinery using non-renewable resources, such as gasoline derived from oil, is an important social value. Minimizing pollutants minimizes the injurious effects on the environment and benefits the health of society on a global scale.
There have been many attempts to attain efficiency increases while minimizing pollutants. The rotary engine is one example of such attempts. The principal characteristics of conventional rotary internal combustion engines are well known in the field of art. Generally, a rotary engine uses the pressure of combustion to move a triangular rotor within an epitrochoidal-shaped rotor housing. The four cycles of conventional combustion—intake, compression, combustion and exhaust—each take place in its own portion of the housing. These cycles cause the rotor to rotate an eccentric output shaft geared to the rotor. The rotary engine seemingly would have increased efficiency due to the decrease of moving parts, a combustion event of 270° of the output shaft rotation on every rotation, and better balance, since the rotor and shaft move in the same direction.
Despite these advantages, the conventional rotary engine has found little commercial success because the long and shallow shape of the combustion chamber hurts both emissions and fuel economy performance with respect to conventional piston engines. The relatively brief time period of the power stroke of the piston on the power portion of the rotary motion does not allow for complete combustion of the fuel. This leads to the exhaust of unburned hydrocarbons that must be cleaned up by a catalytic converter.
Known rotary engines, though capable of producing relatively high power output for their weight and size, have generally been too complex and, in operation, have exhibited excessively high wear, short useful life and relatively high fuel consumption. In operation, they generally produce undesirably high nitric oxide and unburned or partially burned hydrocarbon outputs. All of these add to problems of air pollution. Thus, the efficiency and emissions goals are not satisfied.
Another attempt to meet the efficiency and emissions goals is through the use of diesel cycle engines. The diesel cycle uses compression of a fuel and air mixture to ignite a combustion event, rather than a spark. This allows the diesel engine to utilize direct injection of the fuel and a higher compression ratio than ordinary gasoline. The higher compression ratio results in better efficiency than for ordinary gasoline engines. Moreover, diesel fuel has a higher energy density than gasoline. The combination of greater energy density and higher compression results in much-improved fuel efficiency.
However, diesel cycle engines perform poorly in emissions performance. The combustion in a diesel engine produces significant amounts of polluting nitrogen oxides NO X ). This is especially true in large-scale uses, such as ship engines, or as power sources for electric generation plants. These NO X have been addressed primarily through the use of selective catalytic reduction of the nitrogen oxides. Catalytic converter use at large-scale diesel engines, such as ships and power plants, is not always feasible due to costs and space concerns. Therefore, elimination of the formation of NO X in the combustion chamber has been a focus of technological development.
One measure to reduce NO X in diesel engines is through the injection of water into the combustion chamber to reduce the combustion temperature. The goal is to reduce the peak temperature arising at the flame, which results in a reduction in NO X formation. Forming fewer NO X equals fewer NO X emissions from the engine. Typically, the water is injected into the combustion chamber shortly before combustion, during combustion, or is mixed with the fuel before injection. A conventional four-stroke diesel engine usually injects the water towards the end of the compression stroke. The use of water injection on a piston-driven diesel engine addresses the emissions concerns to a certain degree. However, the use of a four-cycle reciprocating engine design still has the inherent efficiency drawbacks of producing only one 180° power stroke for every other cycle of the piston.
Attempts have been made to design a diesel-fueled rotary engine. U.S. Pat. No. 3,957,021, to Loyd, discloses a rotary diesel engine. Said patent discusses the prior unsatisfactory attempts to utilize diesel fuel in rotary engines. The prior attempts produced unsatisfactory results due to the inability to create sufficient compression in the combustion chamber portion of the rotary housing. The Loyd patent addresses the compression problem by providing a precombustion chamber adjacent to the rotor housing and in communication with the housing.
A fuel injector is disposed in the chamber for injecting fuel into the supplied combustion air. The combustion air is provided, in part, by a compressor, which ensures a sufficient pressure is maintained to combust the diesel fuel. The introduction of fuel into the precombustion chamber in the presence of high pressure and temperature causes the combustion of the fuel to flash into the working chamber of the housing via an outlet port. The burning continues in the working chamber to cause the rotor to rotate the output shaft.
U.S. Pat. No. 6,125,813, to Louthan et al., discloses an alternate method of providing a precombustion chamber to a diesel fueled rotary engine without the need for a separate compressor. However, Louthan and Loyd do not address the emissions issues associated with triangular rotors or with the use of diesel fuel, as discussed previously. Therefore, there is a continuing need to provide an internal combustion engine with improved fuel economy and reduced emissions.
SUMMARY OF THE INVENTION
The positive displacement turbine solves many of the above-indicated problems of rotary engines by providing a rotary engine, which produces an exhaust low in air pollutants while operating efficiently and requiring minimal cooling.
The positive displacement turbine generally comprises a separate compressor, combustion chamber and expansion chamber. The expansion chamber utilizes a crescent-shaped piston, a hub and a cam track in order to extract maximum energy from expanding combustion gases. The positive displacement turbine may also utilize an internal coolant injector system. The coolant injector system assists in cooling the positive displacement turbine, improves efficiency by water injection, and injects a chemical exhaust precipitator into the combustion chamber to react with and precipitate pollutants from the exhaust stream, leaving only carbon dioxide and a few inert gases to escape into the atmosphere.
The positive displacement turbine is adaptable for use with many different fuels, including diesel fuel, gasoline and gaseous fuels including hydrogen. It is adaptable and scaleable for various-sized applications. The invention is also well-adapted to be manufactured from non-traditional engine materials such as composites and ceramics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of the positive displacement turbine according to an embodiment of the present invention;
FIG. 2 is a front sectional view of a combustion chamber according to an embodiment of the present invention;
FIG. 3 is a sectional view of a pass gate sentry valve according to an embodiment of the present invention;
FIG. 4 is a top elevational view of the combustion chamber of FIG. 2 according to an embodiment of the present invention;
FIG. 5 is a side sectional end view through and expansion chamber according to an embodiment of the present invention;
FIG. 6 is a side elevational view of a crescent piston according to an embodiment of the present invention;
FIG. 7 is a front elevational view of the crescent piston of FIG. 6 according to an embodiment of the present invention;
FIG. 8 schematically depicts a sequence of operation showing the relative motions of the hub and a crescent piston according to an embodiment of the present invention;
FIG. 8A depicts the expansion chamber with the crescent piston at top dead center;
FIG. 8B depicts the expansion chamber with the crescent piston at 90° rotation;
FIG. 8C depicts the expansion chamber with the crescent piston at 180° rotation; and
FIG. 8D depicts the expansion chamber with the crescent piston at 270° rotation.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the positive displacement turbine (PDT) 10 generally includes housing 12 , combustion chamber 14 , compressor section 16 and expansion section 18 . The PDT 10 may be constructed from a variety of materials, including conventional steel, cast iron or aluminum, as well as ceramics and composites. Constructing the PDT 10 of aluminum, steel, cast iron or a combination of these materials offers the opportunity for the PDT 10 to be readily manufactured using presently available production facilities without the need for extensive retooling. However, non-metallic low thermal conductivity ceramics and carbon fiber composites may be preferable for construction of the PDT 10 . Ceramics and carbon composites offer the advantages of being strong, lightweight and recyclable, as well as facilitating simple and inexpensive manufacturing of the PDT 10 . A further advantage of the use of ceramics and carbon composites is that they will allow the manufacturing of a hermetically sealed engine unit. A hermetically sealed engine unit will prevent the end user from tampering with the tuning of the engine, thereby maintaining highly efficient operation.
Ceramics are commercially available for many providers, such as Dow-Corning and Champion Spark Plug, Ceramic Division. Carbon fiber composites and other composites are commercially available from DuPont.
Housing 12 generally includes compressor end 20 , center partition 22 , and expansion chamber end 24 . Shaft 26 passes through, and is indirectly supported by, compressor end 20 , center partition 22 and expansion chamber end 24 . Shaft 26 is preferably made of steel, iron or Kevlar carbon fiber composite. Shaft 26 is directly supported by appropriate bearings 28 and sealed by appropriate seals 30 at its passage through each of compressor end 20 , center partition 22 and expansion chamber end 24 . Shaft 26 may be splined or keyed to allow those structures mounted on it to slide longitudinally to accommodate assembly and thermal expansion. DuPont VESPEL® manufactures composite bearings and seals with adequate performance for this purpose.
Compressor section 16 encloses compressor 32 . Compressor 32 is driven by shaft 26 and may be any sort of compressor known to the compressor arts. Compressor 32 is preferably a radial compressor capable of providing sufficient pressure and gas volume to charge combustion chamber 14 . Compressor 32 is preferably an axial single-direction compressor.
Combustion chamber 14 generally includes combustion chamber enclosure 34 , compressor check valve 36 , fuel injector 38 , temperature sensor/glow plug 40 , coolant injector 42 and pass gate sentry valve (PGSV) 44 . Combustion chamber 14 may be designed in various shapes to meet the configuration needs of engines for different specific fuels. For example, combustion chamber 14 may be shaped differently for engines burning unleaded gasoline, propane, #2 fuel oil, natural gas or hydrogen. Hydrogen may be supplied by a Hydrogen on Demand™ system, available from Millennium Cell Inc.
The combustion chamber is constructed from a material tolerant to explosive shock and conductive of thermal energy. For example, combustion chamber 14 may be constructed of carbon-carbon fiber composites or ceramic as well as cast iron, steel, aluminum or other conventional materials. Information on carbon-carbon composites is available from the National Aeronautics and Space Administration. Combustion chamber 14 may be placed in a deliberate position relative to housing 12 , so as to salvage thermal energy from the exhaust as the hot gases pass around the combustion chamber 14 exterior.
Compressor reed valve 35 separates compressor 32 from compressor check valve 36 . Compressor check valve 36 includes valve body 46 , spring 48 , and washer 50 . Compressor check valve 36 allows fluid communication between compressor 32 and combustion chamber 14 when open. Compressor check valve 36 allows fluid flow from compressor 32 into combustion chamber 14 when open, while preventing backflow when closed.
Fuel injector 38 , temperature sensor/glow plug 40 , and, as required for a non-diesel fuel, spark plug 41 are well-known in the internal combustion engine arts and will not be described further.
Coolant injector 42 serves to inject a metered quantity of liquid coolant into combustion chamber 14 . The liquid coolant itself will be described later in this disclosure.
Pass gate sentry valve (PGSV) 44 includes combustion gas passages 52 , valve body 54 , valve piston 55 , valve seat 56 and spring 58 . PGSV 44 is enclosed in PGSV chamber 60 . Combustion gas passages 52 provide fluid communication between combustion chamber 14 and PGSV chamber 60 . Valve body 54 is held firmly against valve seat 56 by spring 58 . PGSV 44 , when open, provides fluid communication between combustion chamber 14 and expansion section 18 .
Expansion section 18 includes expansion chamber redirecting surface 62 , stator body 64 and exhaust port 68 . Stator body 64 along with center partition 22 and expansion chamber end 24 , define expansion chamber 70 . Center partition 22 and expansion chamber end 24 define cam tracks 72 therein. Cam tracks 72 are generally race track-shaped and eccentrically located about shaft 26 . Expansion chamber 70 is generally circular in shape, with a flattened portion at the upper edge thereof, as is readily apparent from FIG. 5 . Stator body 64 further defines rotor seal cavity 74 in which rotor seal 76 is seated.
Further referring to FIG. 5, oscillating piston assembly 78 is enclosed within expansion chamber 70 . Oscillating piston assembly 78 includes piston hub 80 and crescent piston 82 . Piston hub 80 is rotationally secured to shaft 26 while being free to slide longitudinally. Crescent piston 82 is seated in a saddle 84 on the outer diameter 86 of piston hub 80 .
Referring particularly to FIGS. 6 and 7, crescent piston 82 generally includes piston body 88 and piston actuator arm assembly 90 . Piston actuator arm assembly 90 includes actuator arms 92 , cam arms 94 and cam followers 96 . Cam followers 96 are sized to fit closely but to travel freely within cam tracks 72 .
Piston body 88 is generally crescent-shaped and defines an arcuate face 98 , leading edge 99 and a flat face 100 . Flat face 100 further defines a concave piston face contour 102 . Arcuate face 98 is sized and shaped to fit closely and movably into saddle 84 . Leading edge 99 is adapted to follow closely and scour the inner surface of stator body 64 .
Referring particularly to FIG. 8, as piston hub 80 and crescent piston 82 rotate about shaft 26 within expansion chamber 70 , crescent piston 82 defines a path of travel as illustrated in sequential sub FIGS. 8A, 8 B, 8 C and 8 D. As can be seen from FIG. 8, the interaction of cam follower 96 with cam tracks 72 , in combination with the interaction between piston body 88 and saddle 84 , define the motion of crescent piston 82 . This relationship maximizes surface area for gases with an expansion chamber 70 to push against.
Coolant injector 42 is used to inject an injection fluid coolant into combustion chamber 14 during the combustion process. Water injection is well known in the art and has been employed in reciprocating engines since the 1930s. The term “injection fluid coolant” is intended here to mean any non-fuel fluid introduced into the positive displacement turbine 10 internal combustion engine. The injection fluid coolant is made, preferably, of water and a small amount of a chemical alkali; for example, calcium hydroxide or calcium phosphate. The concentration of the alkali component preferably corresponds to the amount of acidic combustion by products produced by the engine during the combustion process. Thus, sufficient base, such as calcium hydroxide, is mixed with the injector fluid to react with and neutralize the resulting acids formed in the combustion process. As is well known, the acid-base reaction yields water and a salt. The case of calcium hydroxide with sulfuric acid is as follows:
C a (OH) 2 +H 2 SO 4 →C a SO 4 .2H 2 O
In operation, compressed air is taken in and compressed by compressor 32 . Compressed air is forced through compressor check valve 36 into combustion chamber 14 . When the pressure has equalized between the outside of compressor check valve 36 and the inside of combustion chamber 14 , compressor check valve 36 closes. After the closing of compressor check valve 36 , fuel injector 38 injects a metered quantity of fuel to mix with the compressed air already in combustion chamber 14 . Compression ignition then occurs to ignite the fuel-air mixture. Alternatively, a spark plug 41 may be provided to the combustion chamber to ignite the fuel-air, depending on the type of fuel used.
Simultaneously with combustion, coolant injector 42 injects a charge of coolant into combustion chamber 14 . Coolant may be injected at another point in time during the combustion cycle, such as prior to the introduction of the compressed air. Coolant is converted to steam with a consequent increase in combustion chamber pressure and reduction in temperature. The gas pressure created by the combustion process forces gas into and through combustion gas passages 52 and acts on valve piston 55 . This opens PGSV 44 . Hot expanding combustion gases then cause PGSV 44 to open, allowing the hot combustion gases, along with the gaseous coolant, to leave combustion chamber 14 and expand into expansion chamber 70 .
At this point in time, crescent piston 82 is located at the top dead-center position, as depicted in FIG. 8 A. The hot combustion gases pass over expansion chamber redirecting surface 62 and then apply force to piston face contour 102 . The force applied causes piston hub 80 to rotate in a clockwise direction, as depicted in FIGS. 8B, 8 C and 8 D.
It should be noted that crescent piston 82 absorbs energy from the hot combustion gases throughout substantially its entire rotation. The location of exhaust port 68 allows the piston to receive force from the hot combustion gases throughout an effective approximate 370° of rotation. The 370° includes a 330° primary exhausting plus a secondary 40° exhausting. Exhaust gas begins to leave expansion chamber 70 at about 330° of rotation and continues for about another 40°. The expanding combustion gases are still applying force to arcuate face 98 of crescent piston 82 , while the next charge of combustion gas is beginning to apply force to piston face contour 102 during the following cycle.
The crescent piston 82 employs the back pressures of the previous combustion cycle to create a sealing force between events. The action of crescent piston 82 and leading edge 99 , in addition to the aerodynamic shape of the piston, accomplishes this. The leading edge 99 of the crescent piston 82 pushes against the previous cycle of gases to exhaust them from the expansion chamber 70 . Sustained high operating temperatures within the positive displacement turbine 10 promote a complete combustion reaction leaving few particulates. Hydrocarbon fuels reacting with oxygen in the air produce large quantities of water vapor or live steam as a product of the reaction. Additional steam is generated from the coolant injected in the combustion chamber 14 .
Expansion chamber 70 has a perimeter shape to accommodate the movements of the crescent piston 82 . The perimeter of the expansion chamber 70 is a circle, flattened in one aspect. This shape may be referred to as a semi-oblate circle.
Expansion chamber redirecting surface 62 is shaped to direct combustion gases at piston face contour 102 and to create a turbulent, circular, centrifugal flow of combustion gases within expansion chamber 70 . Crescent piston 82 includes piston face contour 102 which tends to redirect hot exhaust gases upward and outward, creating a cyclonic gas movement along outer diameter 86 of piston hub 80 , and then in a reverse direction along the interior of expansion chamber 70 . This cyclonic movement of rotating hot gases creates an extremely turbulent gas circulation. This encourages complete oxidation of all components of the fuel. A fundamental principal of the expansion chamber 70 is that the more turbulent the gases in the expansion chamber 70 , the lower the exhaust gas temperature. The cyclonic movement of hot combustion gases also facilitates the chemical reactions between acidic components of the combustion process and the calcium hydroxide or other alkali in the injection cooling fluid, thus facilitating the pH neutralization of acid combustion products.
Further, the expansion of injection fluid coolant into expansion chamber 70 tends to recover thermal energy that would otherwise be wasted through a cooling or exhaust system. Regulating of engine operating temperature may be achieved by monitoring the exhaust gas temperature and by using this data to meter the amount of injection fluid coolant injected.
The PDT 10 engine is configured to take advantage of the high temperatures developed in the combustion chamber 14 to salvage excess thermal energy. Coolant introduced into combustion chamber 14 is converted into live steam, thereby transferring additional force to the drive shaft as useful work. This salvaging of excess thermal energy tends to reduce the need for external air-cooling fins or water jackets. The PDT 10 regulates its operating temperature through the use of injector fluid coolant. It is expected that, for every gallon of petroleum utilized in the PDT 10 , one to six gallons of injector fuel coolant will be used to absorb excess thermal energy. Actual usage will depend upon engine load and conditions.
The present invention may be embodied in other specific forms without departing from the spirit of any of the essential attributes thereof. Therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.
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A rotary engine utilizes an expansion chamber and an oscillating rotary piston to capture the energy of expanding combustion gases through out substantially all of each revolution of the piston. The movement of the oscillating rotary piston is guided by the combined action of a hub having a saddle supporting the rotary piston and a cam track. The invention bums fuel in a separate combustion chamber charged from a coaxially mounted compressor and controlled by a pass gate sentry valve. The rotary engine of the invention is cooled by an internal coolant injection system. The injection fluid coolant solution may contain a alkaline reagent to react with and neutralize acidic components of the combustion gases which would otherwise remain in the exhaust and contribute to air pollution. The rotary engine of the present invention is adaptable to compression ignition fuels and spark ignition fuels. The invention may be constructed of conventional metallic materials as well as composites and ceramics.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and is a divisional of U.S. patent application Ser. No. 11/652,963 filed on Jan. 12, 2007, published on Aug. 2, 2007 as U.S. Publication No. 2007/0178010 A1, now U.S. Pat. No. 7,794,660, which claims priority to and the benefit of U.S. Provisional Application Ser. No. 60/758,799, filed on Jan. 13, 2006, the disclosure of which applications are incorporated herein in their entireties by this reference.
FIELD OF THE DISCLOSURE
The present disclosure relates to a fluid content monitor that can be used, for example, to monitor the residual chlorine level in drinking water, irrigation water, wastewater, and the like.
BACKGROUND OF THE RELATED ART
Various feed, dosing and metering pumps are known for delivering chemical additives to a supply of water or other liquid. Such pumps are particularly useful in fluid content monitors for adding reagents to test drinking, wastewater, and industrial water supplies for the presence of residual chlorine and other constituents. Conventionally, such monitoring has been performed using colorimetric reagent technology wherein a chemical reagent, such as DPD (N,N-diethyl-p-phenylenediamine), is dispensed into a test sample of water contained in a cuvette. The sample turns a certain hue, which depends upon the concentration of the chlorine in the water. This concentration is then photometrically determined by analyzing the hue with an appropriate electronic tester.
In order to obtain accurate test results, precisely measured amounts of reagent must be added to the test sample. Preferably, the reagents include an indicator chemical, such as DPD, and a buffer for adjusting the PH of the test sample. If the amounts of these reagents are not accurately controlled, erroneous measurements are likely to be taken. A dirty or damaged cuvette can also cause erroneous measurements.
What is still desired is a new and improved fluid content monitor that reliably and automatically delivers precisely measured doses of reagents to a water sample so that the sample may be accurately tested for the presence of selected constituent elements such as chlorine.
SUMMARY OF THE DISCLOSURE
Exemplary embodiments of the present disclosure provide a fluid content monitor including a chemical metering pump assembly that reliably and automatically delivers precisely measured doses of reagents to a water sample so that the sample may be accurately tested for the presence of selected constituent elements such as chlorine. The present disclosure also provides a fluid content monitor including a cuvette that can be easily removed without tools for cleaning or replacement.
In one embodiment, the fluid content monitor includes a cuvette, a colorimeter adapted to generate a signal indicative of contents of a fluid sample contained in the cuvette, a container for holding a reagent, and a pump assembly for delivering reagent from the container to the cuvette. The pump assembly includes a tube extending from the container to the cuvette, check valves preventing reverse flow in the tube, and a hammer driven by a solenoid for repetitively compressing the tube to pump reagent to the cuvette.
In another embodiment, the fluid content monitor includes a light transparent cuvette adapted to receive a fluid sample, a colorimeter adapted to direct light through the cuvette, receive the light passing through the cuvette, and generate a signal indicative of contents of the fluid sample based upon the received light, a container for holding a reagent and a pump assembly. Preferably, the pump assemble includes a body having a side wall extending from an end wall to define a chamber, and openings in the side wall adjacent the end wall, a hammer mounted within the chamber of the body for reciprocating linear movement between a retracted position moved away from the end wall and an extended position moved against the end wall, an actuator operatively connected to the hammer, a reagent tube extends from the container for delivering reagent to the cuvette, wherein a resiliently flexible section of the tube passes through the openings in the side wall of the pump body and extends through the chamber between the hammer and the end wall such that the resiliently flexible section is open when the hammer is in the retracted position and substantially closed when the hammer is in the extended position. In a further aspect, an inlet check valve is carried by the reagent tube between the reagent container and the pump to prevent reverse flow to the reagent container, and an outlet check valve is carried by the reagent tube between the pump and the cuvette to prevent reverse flow to the pump.
In another embodiment, the fluid content monitor includes a light transparent cuvette adapted to receive a fluid sample, a container for holding a reagent, a pump adapted to pump reagent from the reagent container to the cuvette and a colorimeter adapted to direct light through the cuvette, receive the light passing through the cuvette, and generate a signal indicative of contents of the fluid sample based upon the received light. The colorimeter preferably includes a body defining a cuvette portal for removably receiving the cuvette, and a passageway extending through the cuvette portal, and a nozzle removably secured in the passageway, wherein the nozzle is adapted to lock the cuvette in the passageway.
In still another embodiment, the fluid content monitor includes a light transparent cuvette adapted to receive a fluid sample, a nozzle connected to the cuvette for introducing reagent into the cuvette, a colorimeter adapted to direct light through the cuvette, receive the light passing through the cuvette, and generate a signal indicative of contents of the fluid sample based upon the received light, a first container for holding a first reagent, a second container for holding a second reagent and a pump assembly. The pump assembly includes a body having a side wall extending from an end wall to define a chamber, and openings in the side wall adjacent the end wall, a hammer mounted within the chamber of the body for reciprocating linear movement between a retracted position moved away from the end wall and an extended position moved against the end wall, an actuator operatively connected to the hammer, a first reagent tube is in fluid communication with the first container for delivering reagent to the cuvette, wherein a resiliently flexible section of the first reagent tube passes through the openings in the side wall of the pump body such that the respective resiliently flexible section is open when the hammer is in the retracted position and substantially closed when the hammer is in the extended position, a second reagent tube is in fluid communication with the second container for delivering reagent to the cuvette, wherein a resiliently flexible section of the second reagent tube passes through the openings in the side wall of the pump body such that the respective resiliently flexible section is open when the hammer is in the retracted position and substantially closed when the hammer is in the extended position, and an inlet check valve carried by the each reagent tube between the respective reagent container and the pump to prevent reverse flow to the reagent containers.
Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only an exemplary embodiment of the present disclosure is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present disclosure. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is made to the attached drawings, wherein elements having the same reference character designations represent like elements throughout, and wherein:
FIG. 1 is a front elevation view of an exemplary embodiment of a fluid content monitor constructed in accordance with the present disclosure, and which can be used, for example, to monitor the residual chlorine level in water;
FIG. 2 is a front perspective view of the chlorine monitor of FIG. 1 shown with a cover removed to illustrate a pump assembly providing fluid connections between chemical reagent containers and a cuvette in a colorimeter;
FIG. 3 is a front elevation view of the chlorine monitor of FIG. 1 shown with the cover and chemical reagent supplies removed;
FIG. 4 is an front perspective view of the pump assembly and the colorimeter of the chlorine monitor of FIG. 1 ;
FIG. 5 is a rear perspective view of the pump assembly including a pump, a pump actuator, tubing, check valves, and a mounting bracket;
FIG. 6 is an exploded rear perspective view of the pump assembly minus the mounting bracket;
FIG. 7 is an enlarged cross-sectional view of the pump, the pump actuator, and the tubing, wherein a hammer of the pump is shown in a retracted position;
FIG. 8 is an enlarged cross-sectional view of the pump, the pump actuator, and the tubing, wherein the hammer is shown in an extended position compressing the tubing;
FIG. 9 is a front perspective view of the colorimeter, wherein the cuvette and a nozzle are shown removed from a body of the colorimeter;
FIG. 10 is an exploded front perspective view of the colorimeter; and
FIG. 11 is a sectional view of the colorimeter.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Referring first to FIGS. 1-3 , an exemplary embodiment of a fluid content monitor 10 constructed in accordance with the present disclosure is shown. The monitor 10 can be used, for example, to measure residual free or total chlorine levels in water. The monitor 10 is equally well-suited for other chemical or industrial processes but is described herein with respect to chlorine monitoring using colorimetric DPD (N, N-diethyl-p-phenylenediamine) chemistry.
The residual chlorine monitor 10 includes a strong, shatterproof case 12 with a removable front cover 14 . The case 12 is also small in size relative to prior art monitors and corrosion-resistant to provide simple installation in a wide array of locations. As shown in FIG. 1 , the front cover 14 defines a window 16 to allow operator monitoring and control. The window 16 provides access to a control panel 18 having touch pad controls 20 and a display panel 22 . The viewing window 16 also allows inspection of a test sample holder or cuvette 30 that contains the fluid being tested.
Referring to FIG. 2 , the residual chlorine monitor 10 is shown with the cover removed and removable first and second containers 40 a, 40 b for chemical reagents secured within the case 12 , while in FIG. 3 the monitor 10 is shown with the containers removed. As shown in FIGS. 2 and 3 , the monitor 10 includes a colorimeter 100 that receives the sample cuvette 30 , and a pump assembly 200 for transferring the reagents from the reagent containers 402 , 40 b to the cuvette 30 . As described in greater detail below, the cuvette 30 is removably mounted within the colorimeter 100 to allow for periodic cleaning or replacement. The colorimeter 100 measures the concentration of a known constituent, e.g., chlorine, of a solution by comparison with colors of standard solutions of that constituent.
Referring to FIGS. 2 and 3 , the chlorine monitor 10 includes an inlet line 60 for receiving a water sample to be tested, and a pressure regulator 62 and inlet valve 64 for controlling flow of the water sample to the cuvette 30 for testing. A drain valve 70 controls flow from the cuvette 30 to a drain line 72 after testing has been completed. According to one exemplary embodiment, both the inlet valve 64 and the drain valve 70 are solenoid-actuated valves.
Electrical power is provided to the chlorine monitor 10 and to the various electrical and electronic components thereof through a connector 80 that extends through the case 12 as shown in FIGS. 1-3 . In the exemplary embodiment shown, a second connector 82 allows the monitor 10 to be attached to one or more alarms (not shown), which are activated when the test results fall outside of predetermined parameters. A third connector 84 allows for on-line communication between the monitor 10 and a remote location.
Although not viewable in the drawings, the chlorine monitor 10 also includes an electronic controller (i.e., computer processor) that is operatively connected to the various components of the monitor 10 . The controller is programmed to control: delivery of the water sample to the cuvette 30 using the water inlet valve 64 ; delivery of the reagents to the cuvette 30 using the pump assembly 200 , testing of the sample using the colorimeter 100 ; and draining of the sample from the cuvette 30 after testing using a water drain valve 70 . Signals representing photometric measurements provided by the colorimeter 100 are processed by the electronic controller, which then displays the results on the display panel 22 . The control panel 18 allows the operator to program and run the residual chlorine monitor 10 according to parameters and operations programmed into the controller. Preferably, the electronic controller is a microprocessor located within the case 12 and is easily configured to exchange signals with other devices via a local area network and the like. In another embodiment, the electronic controller is remotely located from the chlorine monitor 10 .
Referring to FIGS. 4-6 , various detailed views of the pump assembly 200 are shown. The pump assembly 200 includes a pump 210 , a pump actuator 230 , first and second reagent tubes 250 a, 250 b, and check valves 260 a - d . The pump assembly 200 delivers precisely measured and timed dosages of indicator reagent and buffer reagent to the water in the cuvette 30 .
The pump 210 is mounted within the case 12 by a bracket 212 and includes a generally cup-shaped pump body 214 having a sidewall 216 extending from an end wall 218 to define an interior pump chamber 220 . The sidewall 216 includes two openings 222 adjacent the end wall 218 for the reagent tubes 250 a, 250 b as described below. A housing 232 of the pump actuator 230 is secured to an entrance of the pump chamber 220 (with screw threads and a setscrew 213 for example), as best shown in FIG. 6 . Referring to FIG. 6 , the pump 210 also includes a pump hammer 224 within the chamber 220 of the body 214 for reciprocating linear movement between a retracted position moved away from the end wall 218 of the body, as shown in FIG. 7 , and an extended position moved towards the end wall 218 , as shown in FIG. 8 .
Referring in particular to FIG. 6 , the pump actuator 230 is a solenoid. The solenoid includes electromagnet coils (not viewable) located in the housing 232 that are electrically activated through pump solenoid wires 233 connected to the electronic controller. A magnetic armature 234 is slidably mounted within a central opening 235 of the housing 232 , and the armature 234 is connected to the hammer 224 of the pump 210 (with set screws 225 for example) so that an electrical charge delivered to the solenoid 230 by the electronic controller causes linear movement of the armature 234 . The upper end of the armature 234 carries a circumferential retaining ring 236 , and a helical pump return spring 238 is disposed between the upper end of the housing 232 and the retaining ring 236 . The return spring 238 normally biases the retaining ring 236 and the attached armature 234 into the retracted position shown in FIG. 7 . The solenoid 230 is adapted to extend the hammer 224 of the pump 210 when energized and retract the hammer 224 when not energized.
With reference to FIGS. 3-6 , the first reagent tube 250 a connects the first reagent container 40 a with the cuvette 30 , and the second reagent tube 250 b connects the second reagent container 40 b with the cuvette 30 . Both tubes 250 a, 250 b extend from the bottoms of the reagent containers 40 a, 40 b, through covers 42 a, 42 b of the reagent containers, pass through the openings 222 in the pump body 216 , and continue to a nozzle 102 . The nozzle 102 of the colorimeter 100 extends into the cuvette 30 . Air vent tubes 44 a, 44 b also extend from the covers 42 a, 42 b. The openings 222 in the pump sidewall 216 are located so that the tubes 250 a, 250 b lay between the hammer 224 and the end wall 218 of the pump 210 . Both tubes 250 a, 250 b include an inlet check valve 260 a, 260 b, respectively, between the reagent containers 40 a, 40 b and the pump 210 , and an outlet check valve 260 c, 260 d, respectively, between the pump 210 and the colorimeter 100 . The check valves 260 a - d operate to limit the flow of reagent in a single direction from the reagent containers 40 a, 40 b to the cuvette 30 during the pumping cycle. The check valves 260 a - d also prevent air from entering the tubes 250 a, 250 b during the pumping cycle.
To perform testing, the chlorine monitor 10 is primed, i.e., the reagents are added in equal proportion to a test sample in the cuvette 30 . To prime the monitor 10 , the pump 210 operates so that the reagents are delivered from their respective containers to the cuvette 30 . Typically, the electronic controller is programmed to deliver signals to the pump actuator 230 so that the hammer 224 is repeatably driven between the retracted position shown in FIG. 7 and the extended position shown in FIG. 8 .
In the extended position shown in FIG. 8 , the hammer 224 squeezes the segments of the tubes 250 a, 250 b in the chamber 220 to a substantially closed position against the end wall 218 of the pump 210 to create pressure in the tubes 250 a, 250 b. Because the check valves 260 a - d only allow flow towards the cuvette 30 , the fluid in the tubes 250 a, 250 b is urged and moves toward the cuvette 30 . When the hammer 224 returns to the retracted position shown in FIG. 7 , the outlet check valves 260 c, 260 d prevent backflow and a vacuum is created in the tubes to draw the reagents in equal amounts from their respective containers 40 a, 40 b, through the inlet check valves 260 a, 260 b, and into the portions of the tubes 250 a, 250 b located between the inlet check valves 260 a, 260 b and the outlet check valves 260 c, 260 d.
Each tube 250 a, 250 b may comprise a single piece or may be formed by conically interconnected separate tube segments 1 - 3 , as shown for example in FIG. 6 (the tube segments positioned in the reagent containers 40 a, 40 b are not shown in FIG. 6 ). Preferably, the tube segments 250 a - 2 , 250 b - 2 located within the pump body 214 are resiliently flexible and are composed of silicone or similar material. The diameter may be selected to provide for a desired corresponding pumping pressure. The other tube segments 250 a - 1 , 250 a - 3 , 250 b - 1 , 250 b - 3 may comprise a plastic such as polypropylene or other relatively rigid material. The diameter of the tubes 250 a, 250 b is normally relatively small so that excess reagent does not remain within the tube while the pump 210 is not in use. A smaller diameter also helps to facilitate pumping of the reagents through the respective check valves 260 a - d.
In the exemplary embodiment shown, the tubes 250 a, 250 b have equal diameters and equal lengths such that equal amounts of buffer and indicator reagent are drawn through the pumping operation. The reagent containers 40 a, 40 b are thereby depleted together, which facilitates reagent replacement and maintenance of the chlorine monitor 10 . In another embodiment, the separate tubes are combined by a T-shaped fitting to allow a single tube to pass through the pump 210 or a single tube to pass into the cuvette 30 .
In another possible embodiment, the reagents are delivered in unequal amounts. One way to accomplish this is to provide duplicate metering pumps for each tube such that the electronic controller can direct compression of one or both tubes at a time. By independently compressing each tube the ratio of delivery can be modified as desired by the user. In other words, the reagents can be delivered in any ratio, which is determined by the ratio of respective hammer strikes. Further, using different size tubing for the tubes can more permanently vary the reagent ratio.
Referring now to FIGS. 9-11 , the colorimeter 100 is shown in detail. Photometric components of the colorimeter 100 , which are shown best in FIG. 10 , include at least one light source 104 and a light detector or photodiode 106 , for performing colorimetric testing of the sample within the cuvette 30 . The primary light source 104 for measuring the level or concentration of chlorine may comprise, for example, a green light emitting diode (LED) 104 providing a 515 nm light source. Typically, the photodiode 106 is positioned 180° from the primary light source 104 . In operation, the primary light source 104 directs light through the sample water mixed with reagents in the cuvette 30 to the photodiode 106 , which takes measurements representing the level or concentration of chlorine in the water and provides electronic signals representing these measurements. A secondary light source 108 , which is also positioned 180° from the photodiode 106 , is provided for sample level and flow measurement, and may comprise a red LED. The exemplary embodiment also provides a white LED 110 positioned behind the cuvette 30 to illuminate the cuvette 30 for viewing by an operator.
The colorimeter 100 includes a body 112 defining a cuvette portal 114 for removably receiving the cuvette 30 , and a passageway 116 extending through the cuvette portal 114 . The nozzle 102 is removably secured in the passageway 116 and is adapted to extend into the cuvette 30 when secured in the passageway 116 and lock the cuvette 30 in the passageway 116 . In the exemplary embodiment shown, the nozzle 102 is secured with screw threads and can be loosened and tightened by hand to release and secure the cuvette 30 during cleaning or replacement of the cuvette 30 . The cuvette 30 is substantially tubular and includes open ends 31 a, 31 b that align with the passageway 116 of the body 112 .
The discharge ends of the tubes 250 a, 250 b enter the nozzle 102 at intersecting angles to provide improved mixing of the reagents. According to one exemplary embodiment a 10° angle is formed between the tubes 250 a, 250 b at the top of the nozzle 102 . As shown best in FIG. 11 , the body 112 of the colorimeter 100 further includes a sample port 118 intersecting the passageway 116 . A tube 33 for the water sample is connected between the water inlet valve 64 (shown best in FIG. 3 ) and the sample port 118 of the colorimeter 100 . The sample port 118 is offset from a central axis of the passageway 116 of the colorimeter 100 to promote a swirling effect and a mixing of the water and reagents. The sample port 118 extends into the passageway 116 below the cuvette 30 .
As shown best in FIG. 11 , the body 112 of the colorimeter 100 also has an overflow port 120 intersecting the passageway 116 above the cuvette 30 . The nozzle 102 includes side openings 121 for overflow from the cuvette 30 to flow through the overflow port 120 to overflow tubes 74 , 76 connected to the drain 71 (an air vent tube 78 is connected to the overflow tubes and drain).
As shown best in FIGS. 9 and 11 , the colorimeter 100 includes a spring 122 for ejecting the cuvette 30 out of the cuvette portal 114 upon removal of the nozzle 102 from the cuvette 30 . A resiliently flexible retainer 124 is provided in front of the portal 114 for supporting the ejected cuvette 30 so that the cuvette 30 is not allowed to fall and be damaged.
The illustrated embodiments can be understood as providing exemplary features of certain embodiments, and therefore, components and/or aspects of the illustrations can be, without limitation, otherwise combined, interconnected, sequenced, separated, interchanged, positioned, and/or rearranged without materially departing from the disclosed systems or methods. For example, the nozzle and/or discharge tubes may or may not extend into the cuvette. In other embodiments, the discharge tubes may combine the reagent(s) with the fluid remotely from the cuvette and/or the nozzle would facilitate the mixing at another point. For another example, it is envisioned that the reagent(s) can be selected to interact with, and thus monitor, a plurality of compounds independently and collectively such as lead, fluoride and the like.
From the foregoing it may be seen that the present disclosure provides for a fluid content monitor 10 with a solenoid-operated pump assembly 200 and a colorimeter 100 including a removable cuvette 30 . While this disclosure has provided a detailed description of exemplary embodiments, numerous modifications and variations of the fluid content monitor 10 , pump assembly 200 , and colorimeter 100 , all within the scope of the disclosure, will readily occur to those skilled in the art. Accordingly, it is understood that this description is illustrative only of the principles of the disclosure and is not limitative thereof.
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A fluid content monitor including a cuvette, a colorimeter adapted to generate a signal indicative of contents of a fluid sample contained in the cuvette, a container for holding a reagent, and a pump assembly for delivering reagent from the container to the cuvette. The pump assembly includes a tube extending from the container to the cuvette, check valves preventing reverse flow in the tube, and a hammer driven by a solenoid for repetitively compressing the tube to pump reagent to the cuvette. The cuvette can be removed for cleaning and replacement.
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BACKGROUND OF THE INVENTION
Generally, in the automative field, especially with regard to trucks, indicator lamp assemblies are employed as to indicate, by their respective energization, that certain selected functions or vehicular operating parameters are in an unacceptable condition. For example, as in a truck, such indicator lamp assemblies may be operatively connected to related sender units which are, in turn, responsive to indicia of engine oil level, engine temperature, loss of engine coolant, generator or alternator output level, actuation or operation of anti-skid mechanism, air pressure in truck air tanks, headlamp selection (whether high or low beam), or parking brake engagement. Such indicator lamp assemblies often have a lens which emits a colored light upon energization of a bulb carried by the indicator lamp assembly and generally covered or contained by such lens.
There are other lighting requirements within, for example, the truck and especially along the instrument panel thereof. Often there is a need to have a continuous (or switchable) light source for illuminating a desired area as within the truck operator's compartment. This may be to illuminate certain controls which the operator may want to be able to quickly identify during night driving or to illuminate certain gauges or the like. The use of such a continuous illuminating light source as proposed by the prior art has presented problems in that often because of the light rays eminating therefrom in somewhat random direction the lenses of the related indicator assemblies would, in turn, be struck by such light rays and appear to indicate that the related indicator lamp assembly was energized when, in fact, it was not.
In an attempt to overcome this random light ray problem, hood-like structures were employed by the prior art in an attempt to control the path of the illuminating light rays. However, such prior-art hood-like structures, of necessity, were and are relatively large requiring the mounting thereof to, for example, the related lamp structure as by a collar like retainer and for threaded attachment means. Another problem of such prior art hoods is that once affixed to the related lamp assembly, the hood is fixed against further selective adjustment without employing, for example, tools and the like for first loosening the related attachment means. Further, the prior art illuminator hoods are not compatible with standard lamp body or socket structures. That is, they are usually limited to particular physical configurations of a lamp body and, more often than not, actually comprise a portion of a specially designed and built illuminator lamp assembly.
Accordingly, the invention as herein disclosed and claimed is primarily directed to the solution of the foregoing as well as other related and attendant problems.
SUMMARY OF THE INVENTION
According to the invention, an illuminator type lamp assembly comprises lamp body means, means formed on the lamp body means for enabling the lamp body means to be detachably secured to associated support structure, said lamp body means having a first open end for permitting the extension therethrough of an associated lamp bulb, a light shield generally covering said lamp bulb, said light shield having an opening formed in a wall portion thereof for the passage of light rays therethrough, and resilient detent means for operatively engaging said lamp body means for detachably holding the light shield in assembled relationship to said lamp body means and for enabling selective adjustable rotation of said light shield with respect to said lamp body means for achieving a selective direction of the light rays through said opening in said wall.
Various general and specific objects, advantages and aspects of the invention will become apparent when reference is made to the following detailed description considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings wherein for purposes of clarity certain details and/or elements may be omitted from one or more views:
FIG. 1 is a fragmentary perspective view of an interior of a truck cab having an instrument panel employing an illuminator lamp assembly constructed in accordance with teachings of the invention;
FIG. 2 is an enlarged view, partly in cross-section, taken generally on the plane of line 2--2 of FIG. 1 and looking in the direction of the arrows;
FIG. 3 is a cross-sectional view taken generally on the plane of line 3--3 of FIG. 2 and looking in the direction of the arrows;
FIG. 4 is an enlarged view of a fragmentary portion of structure shown in FIG. 2;
FIG. 5 is a cross-sectional view taken generally on the plane of line 5--5 of FIG. 4 and looking in the direction of the arrows;
FIG. 6 is a view similar to that of FIG. 2 but illustrating another form of the invention; and
FIG. 7 is a side elevational view of one form of a bulb socket housing, in somewhat relatively reduced scale, employable in the practice of the invention as depicted, for example, in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in greater detail to the drawings, FIG. 1 illustrates the interior of a truck cab 10 as being comprised of, for example, a driver's or operator's seat assembly 12, steering wheel and column assembly 14, windshield 16, operator's foot actuated levers and pedals 18, 20 and 22, and instrument panel assembly 24 comprising a panel-like support 25 and an array of gauges 26, 28, 30, 32 and 34, controls 36, 38, a plurality of indicator lamp assemblies 44, 46 and 48 and an illuminator lamp assembly 40.
Referring in greater detail to FIG. 2, the illuminator lamp assembly 40 is illustrated as comprising lamp or bulb housing means 50 which, in turn, may be comprised of separable housing sections or housing body portions 52 and 54. The housing portion may be generally tubular having a relatively large outer cylindrical surface 51 terminating at the right end in a transverse end abutment surface 53 and terminating at the left end in a flange-like or shoulder surface 55 formed as by a diametrically necked-down portion 58. The left end of the body portion 52 may have an externally threaded portion 60 which extends from the necked-down portion 58 and terminates at its left in a transverse second end abutment surface 62.
A first clearance type passageway 64 within body portion 52 is defined as by the intersection of oppositely inclined annular ramp surfaces 66 and 68. As is evident from the drawings, ramp means 66 and 68 are so formed as to increase in effective diameter as such ramp means extend away from clearance passageway 64.
The second or inner ramp means 68, as it generally radiates away from passageway 64, terminates and/or blends into a second clearance passageway 72 which, as illustrated, may terminate in a radially outwardly directed shoulder or wall portion 70 formed as by a third further enlarged clearance passageway 74.
As depicted, clearance passageway 74, at its right or rearward end, may terminate as in a third generally radially inwardly directed annular incline or ramp surface 76 which, at its radially innermost end terminates as in a fourth clearance passageway 78. Similar to ramp surface 66, a generally annular incline or ramp surface 80 extends from clearance passageway 78 generally radially outwardly until it terminates in transverse end abutment surface 53.
Body or housing portion 54 may actually comprise a socket assembly formed of electrically non-conductive plastic material with a suitable centrally located cylindrical recess formed therein, as is well known in the art, adapted to receive therein the male plug-in portion 84 of a bulb assembly 56. Also, as is well known in the art, the male plug-in portion 84 may be of the bayonet lock type wherein a tab or lug carried at the side of portion 84 becomes locked against an electrically conductive member within the bulb-receiving recess while a spring loaded contact at the end of the recess engages the end of the portion 84 to thereby complete a circuit through and with bulb 56. As is further well known in the art, the electrically conductive member within the bulb-receiving recess may be physically and electrically connected to a plurality of generally annularly positioned detent-like resilient latching arms, three of which are shown at 86, 88 and 90, each effectively secured to body or housing portion 54. The detent or latching arms may be electrically conductive so that the grounding circuit can be affected as through body portion 52 and panel 25. As generally illustrated, an elongated wire harness 92 (in the embodiment of FIG. 2 such harness comprises a single electrical conductor) is operatively electrically connected at its inner end to the spring loaded contact within body portion 54 while the other end of harness 92 is provided with a suitable terminal contact 94 engageable with related wiring of, for example, the truck cab 10.
In the lamp housing means 50 depicted in FIG. 2, when housing portion 54 is brought toward cooperating housing portion 52, the forward inclined portions of latching arms 86, 88 and 90 operatively engage ramp surface 80 and, upon continued applied force, latching arms 86, 88 and 90 will resiliently deflect radially inwardly as to thereby pass through clearance passageway 78. Once such arms 86, 88 and 90 pass through the clearance passageway, the said latching arms, under their own inherent resilient force, move radially outwardly thereby causing the rearward inclined portions of such latching arms to respectively engage the ramp or annular locking surface 76. The dimensions and configurations of the respective cooperating elements would preferably be such as to cause forward end surface 96 of housing portion 54 to be in abutting relationship with housing end surface 53 prior to latching arms 86, 88 and 90 dissipating all of the inherent resilient force thereby assuring a sound latched engagement as between housing body portions 52 and 54.
As should be apparent, the invention as herein disclosed is not restricted to lamp or bulb socket or body means comprised of two or more separable housing sections or portions. The invention may be practiced equally well where the related lamp or bulb socket or body means comprises a single unitary structure.
FIG. 2, as well as FIGS. 3, 4 and 5, illustrate a light or lamp shield structure 98. In the embodiment disclosed the shield 98 is of a generally cup-like configuration having a first outer cylindrical surface 100 which terminates at or blends into a generally transverse forward or outer end surface 102. Further, in the preferred embodiment, the interior of shield structure 98 is provided with a chamber 104 which may have generally cylindrical surface 106 and which, at its left (as viewed in FIG. 2) or outermost end terminates as in an inner generally transverse surface 108. As can be seen, preferably walls 110 and 112, which respectively define surfaces 100, 106 and 102, 108, are formed integrally with each other. Although not so limited, in the preferred embodiment of the invention shield structure 98 is formed of metal such as, for example, an aluminum alloy.
Still referring to FIG. 2, wall 110 has an annular generally radiating flange or abutment surface 114 which, at its radially inner end, terminates as in a second outer cylindrical surface 116 which, along with inner cylindrical surface 106, terminates at its inner or right end (as viewed in FIG. 2) in a generally transverse end surface 118. The wall 110 also has a slot-like opening 120 formed therein for permitting the passage of light therethrough. Further, in the preferred embodiment, a generally tubular light filter 122 is carried within chamber 104. In this regard it is preferred that the relative dimensions of light filter 122 and surface 106 be such as result in a slight interference fit therebetween as to have light filter 122, in effect, press-fitted into chamber 104. Such filter 122 may be made of any suitable material; however, in the preferred embodiment of such a filter, it was formed of a translucent white polycarbonate. As shown in FIGS. 2,4 and 5, a generally resilient retainer member 124 is carried by shield 98 as within an annular groove 126 formed into the body or wall 110 through surface 116.
Referring in greater detail to FIGS. 4 and 5, each of which is in a relatively substantially enlarged scale, the groove or annular recess 126 is preferably formed as to have opposed annular wall surfaces 128 and 130 which are preferably substantially parallel to each other and generally normal to the axis 132 of shield 98. The side walls 128 and 130 each terminate, as at their radially innermost portion, in a generally cylindrical wall surface 134.
As shown in FIGS. 4 and 5, in the preferred form, retainer 124 is generally circular in transverse cross-section (FIG. 4) and formed into a generally hexagonal configuration (FIG. 5). As can be seen in FIG. 5, the retainer 124, preferably formed of tempered spring steel, comprises a plurality of generally straight or chordal portions 136, 138, 140, 142 and 144 which, as depicted, are integrally joined to arcuate or lobe like portions 146, 148, 150, 152, 154 and 156. Further, as also illustrated lobe portions 146 and 148 have respective chordal portions 158 and 160 which, in turn, terminate as at ends 162 and 164 normally spaced from each other.
As can be seen, the generally inner mid-points or surfaces of chordal or leg-like portions 136, 138, 140, 142, 144, 160 and 158 limit the degree of translational movement which retainer 124 may freely experience relative to wall 110 by abuting engagement with groove or recess outer surface 134. In the preferred embodiment, the relative dimensions are such as to preclude translational movement of any chordal or leg portion beyond a distance where the entire axis thereof is radially outwardly of the radially outermost edge of wall 128 or wall 130. Accordingly, even though such retainer means 124 is generally confined within groove 126 and about surface 134 (which, in effect, functions as a pilot-like portion for retainer means 124) the lobe portions 146, 148, 150, 152, 154 and 156 normally project radially outwardly of the outer cylindrical surface 116.
Therefore, as the shield 98, assumed to be at this time separated from housing means 50, is brought toward housing portion 52 for assembly thereto, lobes or projections 146, 148, 150, 152, 154 and 156 will engage the outer-most ramp surface means 66 and, upon further applied force and movement of shield 98 towards housing section 52, ramp means 66 causes the respective lobes 146, 148, 150, 152, 154 and 156 to move generally radially inwardly toward axis 132. In so doing, of course, spaced ends 162 and 164 move generally toward each other. When thusly sufficiently radially compressed, retainer means 124 passes through clearance aperture 64 and then, because the inherent resilient force thereof, starts to expand radially outwardly and, in so doing, continually engaging the inner ramp or locking surface means 68. Preferably prior to retainer means 124 becoming fully expanded, abutment or shoulder surface 114 of shield 98 engages forward cooperating end surface 62. Accordingly, retainer means 124, simultaneously pressing against recess wall 130 and ramp surface 68, serves to tightly hold shield 98 in assembled relationship to housing means 50.
By having the radially outermost portion of the retainer 124 curved (as viewed in transverse cross-section) it becomes easier to cause radial inward deflection thereof by ramp means 66 during assembly thereof since, regardless of the degree of compression experienced by retainer 124, the outer engaging surface of such lobes is always tangential to the cooperating ramp surface 66.
The retaining arrangement herein disclosed is particularly suitable in those instances where the respective components are relatively quite small and do not permit a convential type of detent locking or latching means because of size limitations. For example, in one successful embodiment of the structure herein disclosed: the nominal diameter of surface 116 was 0.525 inch; the nominal diameter of cylindrical groove surface 134 was 0.485 inch; the width of groove or recess 126 (the distance between walls 128 and 130) was 0.017 inch; the nominal transverse cross-sectional diameter of retainer 124 was 0.015 inch; the nominal diametral distance or clearance between opposed chordal sections of retainer 124 (in its normal or free state) was 0.470 inch; and the nominal diameter of cooperating clearance passageway 64 was 0.530 inch. It should be apparent that with such working dimensions, especially where a clearance aperture is only 0.530 inch in diameter and one has to pass a tubular member therethrough and yet provide a means of detachably locking such tubular member within the clearance passageway, that the prior art means of flat stock C-clip type retainers or the like simply are not employable because of, among other things, the space required to achieve the necessary degree of deflection. In the arrangement disclosed, especially when viewing FIG. 5, it can be seen that as the retainer lobes are forced generally radially inwardly that the radially inner surface of the chordal portions may reach a point where they engage groove surface 134. Any further required radial inward movement such lobes is accomplished with an attendant bending moment experienced as by an adjoining chordal portion bending generally about surface 134. Accordingly, in the arrangement disclosed, it is apparent that the retainer means 124, while undergoing radially directed compression, continually seeks to equalize the forces being experienced by it throughout its entire structure rather than localize forces in any single area for deflection.
Once the shield structure is assembled, as hereinbefore described, the frictional engagement among the various cooperating elements serves to hold the shield structure 98 in any selected position relative to housing means 50. However, if it should be desired to reposition shield 98 as to re-direct the path of light rays, passing through opening 120, all that needs to be done is to firmly grasp the shield 98 and rotate it either clockwise or counter-clockwise, as viewed in FIG. 3, and thereby angularly reposition slot or cut-out 120 to, in turn, re-direct the path of light passing therethrough. Once thusly repositioned, the shield 98 will remain in such selected attitude because of the friction existing as among surfaces 62, 114 and cooperating elements 124, 68 and 130.
The entire illuminator assembly may be supported as on related support or panel means 25 and retained thereagainst as by a washer member 170 and nut 172 cooperating with threaded portion 60.
FIG. 6 illustrates another embodiment of a light shield assembly. All elements in FIG. 6 which are like or similar to those of preceding Figures are identified with like reference numbers provided with a suffix "a".
Referring in greater detail to FIG. 6, and by way of comparison referring also to FIG. 2, it can readily be seen that, in the main, shield structure 98a is comprised as of shield 98 and body portion 52 of FIG. 2. That is, in the embodiment of FIG. 6, the inner surface 106a now extends to and terminates in annular wall 70a and threaded portion 60a and enlarged outer surface 51a are now an integral portion of the wall portion 110a as are ramp surfaces 76a, 80a and enlarged inner surface 74a. In the preferred form of the embodiment of FIG. 6, the surfaces 76a and 80a are preferably circumferentially continuous and the entire shield structure 98a, although able to be formed of any suitable material, is formed of metal such as, for example, aluminum alloy.
As can be seen, the shield structure 98a of FIG. 6 is particularly suitable for those situations where, for any related reason, it is desirable to remove or otherwise service the bulb 56a from the rear of the support panel 25a. That is, the shield structure 98a is itself detachably secured to the support 25a as by the washer member 170a and nut 172a while, in turn, the bulb socket body portion 54a is detachably supported by the shield structure 98a.
FIG. 7, by way of example and not of limitation, illustrates one particular type of bulb socket body portion or means 54a. As thusly depicted, the socket body means 54a may be of plastic or other suitable electrically non-conductive material. The main difference from the body portion 54 of FIG. 2 is that body or housing means 54a has integrally formed electrically non-conductive annularly situated detent or latching members 180, 182, 184 and 186 (which function in the manner of latch means 86, 88 and 90) and a plurality of extending electrical conductors 188, 190, comprising the wiring harness 92a as to achieve, for example, a remote ground connection. There are also many other types of such bulb socket housing means, well known in the art, employable in the practice of the invention.
Although only a preferred embodiment and selected modification of the invention has been disclosed and described, it is apparent that other embodiments and modifications of the invention are possible within the scope of the appended claims.
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A lamp assembly, such as an indicator or illuminator type, has a main body structure detachably securable to an associated support as, for example, an instrument panel of a related vehicle, with such body structure enabling the easy connection thereto of an associated light shield; the light shield carries a separately formed resiliently deflectable detent member enabling easy assembly and disassembly of the shield with respect to the body structure as well as an infinite selection of angular adjustment of the shield relative to body structure.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates generally to the field of radar systems, and more particularly, but not exclusively, to a system and method for combining Displaced Phase Center Antenna (DPCA) and Space-Time Adaptive Processing (STAP) techniques in order to enhance clutter suppression and target detection in radar systems located on moving platforms.
[0003] 2. Description of Related Art
[0004] Moving Target Indication (MTI) radar systems are used to reject signals received from fixed objects (“clutter”), and enhance the detection of signals received from valid, moving targets. Typically, coherent MTI systems use the Doppler shift effect of moving targets to distinguish them from the fixed objects or clutter. Essentially, clutter is a collective term referring to those objects that are not valid targets and cause unwanted radar reflections to mix with target reflections. Examples of clutter are non-moving objects on land surfaces and/or sea surfaces, such as buildings, trees, ocean waves, clouds, rain, etc. As such, clutter is a form of radar interference that hinders the identification of valid, moving targets.
[0005] Numerous techniques exist for the suppression of clutter by stationary, ground-based radars, where the primary clutter return signals are reflections from fixed objects. However, with moving radar platforms (e.g., ship-based radar, airborne radar, space-based radar), the suppression of clutter is a relatively difficult problem, because the clutter also appears to be moving due to the movement of the radar platform. Consequently, the detection of valid, moving targets within a moving clutter environment is a significant technical problem that exists. Thus, it would be advantageous to have an improved radar system and method that can detect valid targets within a moving clutter environment. The present invention provides such an improved radar system and method.
SUMMARY OF THE INVENTION
[0006] The present invention provides a system and method for enhancing the suppression of clutter and target detection in a radar system located on a moving platform. In a preferred embodiment of the invention, a radar system including an MTI subsystem is located on a moving platform (e.g., ship-based, airborne or space-based radar system) with a DPCA processing unit located nearer to the front end of the radar receiver, and a STAP processing unit located nearer to the back end of the onboard processing subsystem. The DPCA processing unit provides gross cancellation and suppression of the received clutter signals, and the STAP processing unit provides fine tuning for the clutter suppression process. In other words, the front end DPCA processing unit removes most of the rapidly varying clutter, which gives the back end STAP processing unit a more benign clutter environment to process. As such, using a DPCA processing unit or stage on a space-based radar platform improves system performance, because the space-based platform is relatively stable and not subject to air turbulence or wave motion. Also, using a DPCA processing unit or stage provides independence from clutter statistics, which is important because relatively little empirical clutter data is available from space-based radar platforms. Using a STAP processing unit or stage for clutter suppression on the space-based radar platform provides fine tuning of the suppression process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0008] FIG. 1 depicts a pictorial representation of an example of a space-based radar system environment, which can be used to illustrate a preferred embodiment of the present invention;
[0009] FIG. 2 depicts a block diagram of a radar system that can be used to implement a preferred embodiment of the present invention;
[0010] FIG. 3 depicts a block diagram of an MTI processing system that can be used to implement a preferred embodiment of the present invention;
[0011] FIG. 4 depicts a pictorial representation of an example DPCA antenna structure that can be used to implement a preferred embodiment of the present invention;
[0012] FIG. 5 depicts a block diagram of an example ECCM/beam-forming processing function that can be used to implement beam-forming processing unit 306 shown in FIG. 3 ;
[0013] FIG. 6 depicts a block diagram of an example Doppler filtering processing unit that can be used to implement Doppler processing unit 308 shown in FIG. 3 ;
[0014] FIG. 7 depicts a block diagram of an example pulse compression processing unit that can be used to implement pulse compression processing unit 310 shown in FIG. 3 ;
[0015] FIG. 8 depicts a block diagram of an example STAP processing unit that can be used to implement STAP processing unit 312 shown in FIG. 3 ; and
[0016] FIGS. 9A and 9B depict related block diagrams of example CFAR processing units that can be used to implement CFAR processing unit 314 shown in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Referring now to the figures, FIG. 1 depicts a pictorial representation of an example of a space-based radar system environment 100 , which can be used to illustrate a preferred embodiment of the present invention. For this exemplary embodiment, an MTI radar system 102 is located on a satellite platform that is in orbit over a portion of the Earth 106 . The satellite platform for radar system 102 can be in a Highly Elliptical Orbit (HEO), a Medium Earth Orbit (MEO), or a Low Earth Orbit (LEO). Also, radar system 102 can be located on a space-based vehicle or station, such as, for example, a space shuttle or similar space vehicle, space-based laboratory, space station, etc. As such, radar system 102 can be located on any appropriate space-based platform. In any event, although a space-based radar system is described with respect to this embodiment, the present invention is not intended to be so limited, and can include radar systems located on other moving platforms as well, such as, for example, airborne or ship-based radar systems.
[0018] Preferably, for this embodiment, radar system 102 includes a phased-array antenna subsystem that can generate an electronically-shaped and electronically-steerable antenna radiation pattern 104 . As shown, radiation pattern 104 depicts a principal lobe of the antenna pattern, which is directed towards a moving target (e.g., aircraft) 112 . Also, certain secondary lobes of antenna pattern 104 are shown directed, for example, towards land-based clutter 108 and sea-based clutter 110 . For this embodiment, the electronically-steerable antenna subsystem can be a phased-array, but it can also include any appropriate antenna structure that can be divided into at least two antenna segments (e.g., typically sharing antenna elements) or one antenna with a plurality of phase centers, which can be used for DPCA processing.
[0019] FIG. 2 depicts a block diagram of a radar system 200 that can be used to implement a preferred embodiment of the present invention. For illustrative purposes only, radar system 200 is described herein for a space-based platform, such as, for example, the satellite platform for radar system 102 shown in FIG. 1 . However, the present invention is not intended to be so limited, and radar system 200 can also be located on any other suitable airborne, ship-based or space-based platform.
[0020] For this exemplary embodiment, radar system 200 includes an electronically steerable antenna subsystem 202 , with a plurality of antenna elements 204 a - 204 n . For example, antenna subsystem 202 can be a phased array antenna subsystem, or an adaptive array antenna subsystem. Preferably, antenna subsystem 202 is any appropriate antenna structure that can be divided into at least two antenna segments (e.g., typically sharing antenna elements) or one antenna with a plurality of phase centers, which can be used for DPCA processing.
[0021] A beam steering controller 206 is connected to electronically steerable antenna subsystem 202 for directing the radiation pattern of antenna elements 204 a - 204 n . An exciter/transmitter stage 210 is connected to a circulator 208 , which couples the transmission pulses generated by exciter/transmitter stage 210 to antenna subsystem 202 and antenna elements 204 a - 204 n . Circulator 208 is also connected to a receiver stage 212 and couples received signals from antenna elements 204 a - 204 n through antenna subsystem 202 to receiver stage 212 . Receiver stage 212 is connected to a programmable onboard processing subsystem 214 , so that the raw data in the receiver stage 212 is coupled to programmable onboard processing subsystem 214 .
[0022] Programmable onboard processing subsystem 214 is connected to an onboard processing configurator stage 220 and a communication subsystem 226 . System health and status data, and mode or context control data, are coupled from/to programmable onboard processing subsystem 214 to/from onboard processing configurator stage 220 , respectively. Processed data and target report data are coupled from programmable onboard processing subsystem 214 to communication subsystem 226 , which enables communications between programmable onboard processing subsystem 214 and a ground station (not shown) via an uplink/downlink antenna.
[0023] A real-time waveform designer stage 218 is connected to onboard processing configurator stage 220 , beam steering controller stage 206 , exciter/transmitter stage 210 , receiver stage 212 , and a spacecraft attitude determination and control stage 216 . As such, the real-time waveform designer stage couples waveform design parameters and synchronization signals between stages 220 , 206 , 210 , 212 and 216 . A radar event scheduler/time line generator stage 222 is connected to real-time waveform designer stage 218 , programmable onboard processing subsystem 214 , spacecraft attitude determination and control stage 216 , spacecraft guidance navigation and control stage 224 , and communication subsystem 226 . Thus, the data coupled from control stages 216 , 224 and subsystems 214 and 226 to real-time waveform designer stage 218 are used to generate timing and synchronization information for the radar system 200 and its space-based platform. Spacecraft attitude and position are coupled to the beam steering controller stage 206 to point the beam at the desired location on the earth. In this manner, the attitude, direction and velocity of the space-based platform can be considered and synchronized with the timing of the radar system's transmitter and receiver stages.
[0024] FIG. 3 depicts a block diagram of an MTI processing system 300 that can be used to implement a preferred embodiment of the present invention. For this exemplary embodiment, MTI processing system 300 is preferably a coherent MTI processing system, but the present invention is not intended to be so limited and can include a suitable non-coherent processing system as well. As an example, MTI processing system 300 can form part of radar receiver stage 212 shown in FIG. 2 .
[0025] MTI processing system 300 includes an Analog-to-Digital (A/D) converter unit 302 coupled to the back end of a suitable receiver stage. Thus, for this example, analog signals (e.g., targets, clutter, etc.) input from the receiver's front end (e.g., coupled from circulator 208 in FIG. 2 ) are converted to digital signals by A/D converter unit 302 . As such, A/D converter unit 302 quantizes continuous signals input from the receiver's front end into a series of discrete values for digital processing.
[0026] A/D converter 302 is connected to a DPCA processing unit 304 . Alternatively, for example, DPCA processing unit 304 could be implemented before the A/D converter 302 (e.g., in the antenna manifold). For this exemplary embodiment, the primary purpose of DPCA processing unit 304 is to provide gross cancellation and suppression of received clutter signals. For illustrative purposes, refer now to FIG. 4 for a description of an example DPCA antenna structure 400 that can be used to implement the present invention. For example, the concept of DPCA antenna structure 400 can be used for implementation of some or all of antenna elements 204 a - 204 n depicted in FIG. 2 .
[0027] DPCA antenna structure 400 can be located on a single platform and include a plurality of identical antennas (e.g., two identical antennas having shared antenna elements) 402 , 404 with separate forward and aft phase centers 406 , 408 , respectively. Alternatively, DPCA antenna structure 400 can include one antenna with a plurality of phase centers 406 , 408 . At an appropriate time (e.g., determined by the velocity of the platform for radar system 200 in FIG. 2 relative to the rotation of the Earth), a transmitter subsystem (e.g., exciter/transmitter 210 in FIG. 2 ) for radar system 200 transmits a signal from the first antenna 402 . A receiver (e.g., receiver stage 212 in FIG. 2 ) receives a return signal from antenna 402 . The transmitter subsystem and receiver respectively transmit and receive signals via the second antenna 404 , when the aft phase center 408 has moved into a position that substantially matches the location of the forward phase center 406 when the first transmission and reception occurred. Such movement of DPCA antenna structure 400 is indicated by the arrow 410 .
[0028] As such, in accordance with the present invention, a DPCA processing technique is used to subtract the radar return signals received in response to two transmissions, which cancels most of the rapidly-varying clutter signals received. This technique effectively cancels out the motion of the platform and, therefore, makes the onboard radar sensor appear to be stationary. In other words, subtracting the radar returns from the two transmissions cancels a large part of the stationary clutter (e.g., mountains, buildings, etc.) and ideally leaves only moving targets of interest for further processing. However, although this DPCA processing technique mitigates the clutter returns from stationary objects, some residual clutter can remain (e.g., return signals due to tree branches and leaves blowing in the wind, ocean wave motion, etc.). As a practical matter, performance of the DPCA technique is primarily a function of: (1) how well the two antenna segments are matched; (2) the preciseness of the timing of the transmission of the second pulse; and (3) the location of the aft phase center 408 relative to the location of the forward phase center 406 when the respective transmissions and receptions occur.
[0029] Returning to FIG. 3 , DPCA processing unit 304 is connected to beam-forming (or beam formation) processing unit 306 . For example, beam-forming processing unit 306 can be implemented using Electronic Counter-Countermeasures (ECCM) beam-forming processing function. As such, the inputs (e.g., coupled to DPCA processing unit 304 ) to beam-forming processing unit 306 can include, for example, 16 channels representing 12 sub-array antenna channels and 4 auxiliary antenna channels (e.g., with 3 time-taps per auxiliary channel). The inputs to beam-forming processing unit 306 can also include, for example, steering vectors for the output beams (e.g., 4 output beams), in a 24 by 4 matrix, with 24 weights per output beam. Thus, beam-forming processing unit 306 can perform processing for each sub-band (e.g., 36 sub-bands), each pulse (e.g., 256 pulses), and each range gate (e.g., 3333 range gates) in this exemplary embodiment.
[0030] FIG. 5 depicts a block diagram of an example ECCM/beam-forming processing function 500 that can be used to implement beam-forming processing unit 306 in FIG. 3 . For example, beam-forming processing unit 500 can include a 10 msec buffer 502 connected to an input of beam-forming processing unit 306 in FIG. 3 . A sample matrix 504 is coupled to buffer 502 and can be used for computing adaptive weights by creating a sample matrix (e.g., 24 by 256 matrix) based on pre-transmit collection of data. For example, the sample matrix can be formed by selecting 256 samples for each of the main channels involved (e.g., 12 main channels) and with 3 time-taps per auxiliary channel (e.g., 4 auxiliary channels). Then, a set of adaptive weights can be computed by an adaptive weight computation function or process 506 based on the sample matrix 504 created, and also a 4 by 24 matrix of the steering vectors involved. Thus, as a result, a 4 by 24 matrix of adapted weights can be applied to ECCM/beam-forming processing unit 508 to create (e.g., via a 16-element matrix multiplication) a 4 by 3333 matrix output (e.g., to be coupled from beam-forming processing unit 306 in FIG. 3 to Doppler processing unit 308 ). As such, beam-forming processing unit 306 can produce a 24-element matrix multiplication for each beam formed, and this process can be performed for each sub-band (e.g., 36), pulse (e.g., 256) and range gate (3333) involved.
[0031] Returning to FIG. 3 , for this exemplary embodiment, the output of beam-forming processing unit 306 is shown connected to an input of Doppler processing unit 308 , and an output of Doppler processing unit 308 is shown connected to an input of pulse compression processing unit 310 . However, for suitable back end processing, it should be understood that the order of the Doppler and pulse compression processing units can be interchanged. In other words, the output of beam-forming processing unit 306 can be connected to an input of pulse compression processing unit 310 , and an output of pulse compression processing unit 310 can be connected to an input of Doppler processing unit 308 . Essentially, for such an embodiment, Doppler processing unit 308 can perform a Fast-Fourier Transform (FFT) across the radar pulses to convert the input data to the frequency (or Doppler) domain. Pulse compression processing unit 310 can use a matched filter technique that allows a long-pulse radar with moderate output power to appear to be a higher power, short-pulse radar with greatly increased range resolution.
[0032] FIG. 6 depicts a block diagram of an example Doppler filtering processing unit 600 that can be used to implement Doppler processing unit 308 in FIG. 3 . For example, Doppler filtering processing unit 600 can include a side-lobe weighting vector multiplication processing unit 602 connected to an input of Doppler processing unit 308 in FIG. 3 . An FFT processing unit 604 is coupled to vector multiplication processing unit 602 and can be used for performing an FFT function on each weighted element received from side-lobe weighting vector multiplication processing unit 602 . For this exemplary embodiment, 256 pulses are coupled to the input of side-lobe weighting vector multiplication processing unit 602 , which performs a 256-element vector multiplication of the input pulses by a set of tapered weights, for example a cosine squared on a pedestal window. As such, a 1 by 256 element vector created by side-lobe weighting vector multiplication processing unit 602 is coupled to the input of FFT processing unit 604 , which performs, for this example, 256-point FFT's on the weighted samples from side-lobe weighting vector multiplication processing unit 602 . Processing unit 602 creates a 1 by 256 element vector including the 256-point weighted, FFT data. Thus, as a result, using the processing techniques shown in FIG. 6 , Doppler processing unit 308 in FIG. 3 can perform Doppler filtering in the pulse/Doppler dimension.
[0033] In this regard, processing units 602 and 604 can perform Doppler filtering and processing for 256 pulses, each range gate (e.g., 71,983 range gates), each beam (e.g., 4 beams), and each sub-band (e.g., 1 sub-band) involved. The output of processing unit 604 (e.g., and Doppler processing unit 308 ) can include, for example, 256 Dopplers for 71,993 range gates, 4 beams, and 1 sub-band. The Doppler processing and filtering can be performed twice on staggered sets of received pulses to generate an output with additional temporal degrees of freedom to support post-Doppler STAP processing. At this point, it should be understood that the present invention is not intended to be limited to the above-described staggered implementation and can also include other implementations such as, for example, beam-staggered STAP implementations and element-staggered implementations.
[0034] FIG. 7 depicts a block diagram of an example pulse compression processing unit 700 that can be used to implement pulse compression processing unit 310 in FIG. 3 . Notably, as mentioned earlier, pulse compression processing unit 310 may be interchanged with Doppler processing unit 308 in FIG. 3 . However, for the embodiment(s) shown in FIGS. 3 and 7 , pulse compression processing unit 700 can include an N-point FFT processing unit 702 connected to an input of pulse compression processing unit 310 in FIG. 3 , which, for this example, can perform a FFT on each of 89,991 range gates to create an M by N matrix of the FFT data. A vector multiplication processing unit 704 performs a vector multiplication of the M by N matrix of the FFT data with reference data from a 1 by N vector, and creates an M by N matrix including the resulting vector multiplied data.
[0035] Each 1 by N vector from vector multiplication processing unit 704 is applied to the input of an N-point Inverse FFT (IFFT) processing unit 706 , which performs an IFFT function on the data from the M by N matrix. In this manner, for this example, processing units 702 , 704 and 706 perform a frequency domain convolution on the input pulses (e.g., pulses from 89,991 range gates). For example, this processing can be performed as one large FFT, or more practically, with a number of smaller FFTs using overlap-add or overlap-save techniques. Preferably, the input pulses are uncompressed LFM Chirp waveform length TBD range gates. As such, a linear convolution may be performed on this data in the time domain or the frequency domain. For this example, processing units 702 , 704 and 706 perform frequency domain convolution (e.g., forward FFT performed by processing unit 702 , element-by-element vector multiplication performed by processing unit 704 , and inverse FFT performed by processing unit 706 ). The output of the overall convolution process is provided in an M by N matrix at the output of N-point IFFT processing unit 706 . As such, an “overlap save” function can be performed if the FFT size either cannot handle all ranges or is inefficient in a single execution. Preferably, for this embodiment, for frequency domain convolution, the uncompressed waveform matched-filter weights and/or the frequency domain representation (transformation) are pre-computed.
[0036] The M by N matrix created by processing unit 706 is applied to a select/truncate processing unit 708 , which performs a truncation. Thus, as a result, the output of select/truncate processing unit 708 can provide 71,993 ranges, and thus pulse compression processing is provided by processing units 702 , 704 , 706 and 708 (e.g., by pulse compression processing unit 310 in FIG. 3 ) for each pulse (e.g., 256 pulses), each beam (e.g., 4 beams), and each sub-band (e.g., 1 sub-band) involved.
[0037] Returning to FIG. 3 , for this exemplary embodiment, an output of pulse compression unit 310 is connected to an input of STAP processing unit 312 . Thus, in accordance with the present invention, the Doppler processed, pulse-compressed data from processing units 308 , 310 can be applied to STAP processing unit 312 for fine-tuning of the clutter cancellation process in the example MTI processing stage depicted in FIG. 3 (e.g., in addition to the gross cancellation process performed by DPCA processing unit 304 ).
[0038] Essentially, in spatial adaptive processing, energy arriving at the antenna elements at different times and phases is used to determine the direction from which unwanted or undesired signals are arriving. The environment is sampled. The sampled data are used to create a training matrix. The training matrix is inverted and solved against desired steering vectors to generate adaptive weights which, when applied to the incoming signals, maximize sensitivity to signals in the desired directions, while nulling out or canceling unwanted or undesired signals. This spatial adaptation technique can be extended to STAP processing by forming a covariance (training) matrix across the input antenna elements (spatial diversity) and the radar pulses (temporal diversity), and then solving for adaptive weights. Adding a temporal aspect allows the STAP technique to be used for clutter cancellation as well as jammer nulling. As such, DPCA processing may be considered a degenerate form of STAP with only two degrees of freedom.
[0039] FIG. 8 depicts a block diagram of an example STAP processing unit 800 that can be used to implement STAP processing unit 312 in FIG. 3 . For example, STAP processing unit 800 can include a sample matrix 802 (e.g., coupled to an input of STAP processing unit 312 in FIG. 3 ), which can be used for creating a sample matrix (e.g., a 4 by 500 matrix) from the input samples (e.g., 256 pulses). The input can include, for example, for each of 36 sub-bands, 4 Doppler-staggered beams, 71,993 ranges, and 256 pulses. The resulting sample matrix can be applied to an adaptive weight computation processing unit 804 , which can compute a set of adaptive weights based on the sample matrix 802 created, and also a 3 by 4 matrix of the steering vectors involved (e.g., steering vectors for 3 output beams in a 3 by 4 matrix for 4 weights per output beam formed). Thus, as a result, a 3 by 4 matrix of adapted weights can be applied to STAP beam-forming processing unit 806 to create (e.g., via a 4-element matrix multiplication per output beam) a 3 by 71,993 matrix output (e.g., to be coupled from STAP processing unit 312 in FIG. 3 to Constant False Alarm Rate (CFAR) processing unit 314 ).
[0040] As such, as a result of the processing performed by processing units 802 , 804 and 806 in FIG. 8 , STAP processing unit 312 can produce (e.g., for an input of 256 pulses for 4 input beams, and steering vectors for 3 output beams) an output of 256 Dopplers for 71,993 ranges, and 3 clutter-nulled beams. This STAP beam-forming process can be performed for each sub-band (e.g., 36), each Doppler (e.g., 256), and each range gate (e.g., 71,993) involved.
[0041] Thus, in accordance with the present invention, the STAP beam-forming processing unit 312 can compute the power for each beam, whereby the beam nearest the center of the clutter is used to select 500 samples to form the sample matrix and for computing the adaptive weights (e.g., the selection of the 500 samples can be performed by the Doppler processing unit 308 in FIG. 3 ). Then, the adaptive weights can be computed based on the sample matrix. The STAP beam-forming processing unit can then multiply a 4-element vector for each beam, sub-band, Doppler and range involved.
[0042] Returning to FIG. 3 , for this embodiment, an output of STAP processing unit 312 is connected to an input of CFAR processing unit 314 . FIG. 9A depicts a block diagram of an example CFAR processing unit 900 A that can be used to implement CFAR processing unit 314 in FIG. 3 . For example, CFAR processing unit 900 A can include a summing/averaging processing unit 902 A (e.g., coupled to an output of STAP processing unit 312 via a shift register). An output of summing/averaging processing unit 902 A is connected to an input of a local threshold establishment processing unit 904 A. An output of the local threshold establishment processing unit 904 A is connected to an input of a comparison processing unit 906 A.
[0043] In operation, for this exemplary embodiment, the input to the CFAR processing function 900 A is a real sequence formed from the magnitude of the returns for each range cell. For each range cell of interest, a window of N cells is formed around the cell of interest, and the average energy of the returns in the window (excluding the cell of interest and one or more “guard cells” on either side of the cell of interest is computed. This average is used to establish a local threshold which will be used to declare the presence or absence of a target when compared with the magnitude of the return in the cell of interest. The threshold is set to maximize the Probability of Detection (P D ) and minimize the Probability of False Alarm (P FA ), while attempting to avoid the making of a decisional error, such as, for example, declaring no target when a target is actually present, or declaring a target when none is present. The “window” can be slid from cell to cell, or through the entire sequence of range cells. However, care must be taken when dealing with range cells on the extremes, because the window from which the samples are taken is not symmetric.
[0044] As such, a number of techniques may be used to compute the average and use the threshold. For example, the average can be computed from scratch each time. Also, a more computationally efficient approach realizes that, for the next movement of the window, most of the “sum” already exists. Adding the contributions from the leading edge of the window and the left-most guard cell from the previous window, and subtracting the contributions from the trailing edge of the window and the right-most guard cell from the previous window, is all that is needed to create the new sum. It is also possible to perform this summation as a sliding matrix multiplication of the input cells with a . . . 111110000011111 . . . mask.
[0045] FIG. 9B depicts a block diagram of a second example CFAR processing unit 900 B that can be used to implement CFAR processing unit 314 in FIG. 3 . As such, CFAR processing unit 900 B is a 2-dimensional (range and Doppler) CFAR, while CFAR processing unit 900 A in FIG. 9A is a 1-dimensional (range) CFAR. For this example, CFAR processing unit 900 B can include an extraction processing unit 902 B for extracting a cell of interest from the input, and zeroing out the cell and guard cells. An output of extraction processing unit 902 B is connected to an input of a summing/averaging processing unit 904 B. An output of summing/averaging processing unit 904 B is connected to an input of a local threshold establishment processing unit 906 B. An output of the local threshold establishment processing unit 906 B is connected to an input of a comparison processing unit 908 B.
[0046] In accordance with the present invention, the output of CFAR processing unit 900 A in FIG. 9A or 900 B in FIG. 9B is detected video/target information with enhanced clutter suppression due to the use of DPCA and STAP processing techniques. This video/target information can be transferred to the ground via the communication subsystem unit 226 and coupled to a video/target display for use by an operator (e.g. from CFAR processing unit 314 in FIG. 3 at the back end of the programmable onboard processing subsystem 214 shown in FIG. 2 ).
[0047] In operation, CFAR processing unit 900 B can perform a 2-dimensional CFAR function. A sliding window cell-averaging algorithm can be used for sizing purposes. A primary difference between the 2-dimensional CFAR in FIG. 9B and the 1-dimensional CFAR in FIG. 9A is that the local averaging is accomplished in the 2-dimensional CFAR 900 B in FIG. 9B using the Doppler cell of interest and adjacent Doppler cells above and below the Doppler cell of interest. However, no guard banding is used in the Doppler dimension (i.e., all range gates in the adjacent Doppler cells are included in the average and subsequent threshold determinations).
[0048] It is important to note that while the present invention has been described in the context of a fully functioning radar processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such as a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communications links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The computer readable media may take the form of coded formats that are decoded for actual use in a particular radar processing system.
[0049] The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
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A system and method are disclosed for enhancing the suppression of clutter and target detection in a radar system located on a moving platform. For example, a radar system including an MTI subsystem is located on a moving platform (e.g., ship-borne, airborne or space-based radar system) with a DPCA processing unit located nearer to the front end of the radar receiver, and a STAP processing unit located nearer to the back end. The DPCA processing unit provides gross cancellation and suppression of the received clutter signals, and the STAP processing unit provides fine tuning for the clutter suppression process. In other words, the front end DPCA processing unit removes most of the rapidly varying clutter, which gives the back end STAP processing unit a more benign clutter environment to process. As such, using a DPCA processing unit on a space-based radar platform improves system performance, because the space-based platform is relatively stable and not subject to air turbulence or wave motion. Also, using a DPCA processing unit provides independence from clutter statistics, which is important because relatively little empirical clutter data is available from space-based radar platforms. Using a STAP processing unit for clutter suppression on the space-based radar platform provides fine tuning of the suppression process.
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GRANT REFERENCE
The invention described herein was made in the course of work under a grant or award from the Department of Health, Education and Walfare.
BACKGROUND OF THE INVENTION
Kalafungin, grantican B and the nanaomycins are members of a growing family of naturally occurring antibiotics containing quinones fused to a pyrano-gamma-lactone moiety. Clinical testing has shown kalafungin to be inhibitory in vitro against a variety of pathogenic fungi, yeasts, protozoa and gram positive and gram negative bacteria. To date, no synthetic approaches to this interesting class of natural products have appeared.
This invention has as its primary objective an overall synthesis route for this class of antibiotic compounds. In addition, a new and novel antibiotic compound, which is not naturally occurring, 9-deoxykalafungin, has been prepared. And tests show this compound to exhibit, in some instances, superiority in terms of inhibitory effect when compared to naturally occurring kalafungin.
Accordingly, one object of the invention is to prepare via synthetic approaches, an interesting class of natural products by construction of the basic ring system of the quinone pyrano-gamma-lactone antibiotics in a short, efficient synthesis route.
Yet another object of this invention is to prepare such compounds as mentioned above at yield levels which are economically feasible for mass production.
A still further object is to prepare 9-Deoxykalafungin.
The method and manner of accomplishing each of these stated objectives will become apparent from the detailed description of the invention which follows.
SUMMARY OF THE INVENTION
A method of preparing quinone pyrano-gamma-lactone antibiotics such as kalafungin and 9-deoxykalafungin, which comprises reacting, under anhydrous conditions, a two position functionally substituted 1,4 naphthoquinone with an alkoxy furan, to provide a first synthesis intermediate having the carbon skeleton structure of the antibiotic. Thereafter, an alkylating agent is added to the synthesis intermediate to protect the 1,4 position keto groups, the functional groups of the two position substituted moiety are reduced to alcoholic groups, and after the reduction which is preferably a hydride reduction, a deblocking agent and a cyclization agent are added to provide removal of the alkyl portion of the alkoxy group and to provide ring formation between the alcoholic group of said two position substituent and said furan ring, and finally oxidative dealkylating of the 1,4 positions occurs to provide a quinone pyrano-gamma-lactone antibiotic, such as kalafungin or 9-deoxykalafungin.
DETAILED DESCRIPTION OF THE INVENTION
As heretofore mentioned, kalafungin is a known antibiotic. It is an effective anti-fungal agent. Heretofore it has been prepared via a fermentation broth of the microorganism Streptomyces tananshunsis. Such fermentation processes are, of course, expensive, time consuming and provide poor overall yields. For further details with regard to such processing for kalafungin, see Johnson and Dietz, Appl., Microbiology, 16, 1815 (1968), which is incorporated herein by reference.
Kalafungin, grantican B, nanaomycins and deoxykalafungin all have in common a basic naphthoquinone pyrano ring, the official name of which is 1-H Naptho [2,3-c] pyran 5,10 dione. The basic discovery of this invention involves synthesis of this ring structure, with, of course, substituted moieties which may be added to the basic ring structure for synthesis of any particular quinone pyrano-gamma-lactone antibiotic. Heretofore, there has been no successful synthesis route for preparation of these type of compounds.
In the first step of the synthesis, a two position functionally substituted 1,4 naphthoquinone having the formula: ##STR1## is reacted with an alkoxy furan having the formula: ##STR2## With respect to the naphthoquinone, R* may be a lower alkyl group, hydrogen, an alkoxy group or hydroxyl as well as chloride. A precise moiety represented by R is not critical and is merely selected dependent upon the ultimate antibiotic compound being prepared. For example, when kalafungin is prepared, R represents OH, and when deoxykalafungin is prepared, R represents hydrogen. Similarly, if grantican B is being prepared, or the nanaomycins R represents a hydroxyl group.
"A" can be virtually any moiety which in subsequent processing steps can be reduced to an alcoholic functional group for use during the cyclization step. For example, it can be lower keto groups, ester groups, aldehyde groups or a nitrile group. In preparing kalafungin and deoxykalafungin, it is most preferred that "A" be a keto group. Specifically for these two mentioned compounds, it is most preferred that "A" be an acetyl group, that is --CH 3 C0. Generally, it is preferred that A be a keto group of C 1 to C 10 chain length.
Turning now to the alkoxy furan reaction ingredient, R' may be any moiety which is easily removable with dilute acid. That is, any acid labile group has been found satisfactory. For most purposes, and therefore preferred with respect to the process of this invention, R' can be tertiary butyl or tertiarybutyldimethylsiloxy moieties. Both of these are preferred because they are easily removable by dilute acid in subsequent processing steps. However, it should be understood that R' may also be other lower acid labile groups such as methoxymethyl.
The initial reaction between the naphthoquinone reactant and the alkoxy furan must be conducted under anhydrous conditions because water would react with the quinone structure. Similarly, the presence of other solvents which have hydroxyl groups must be avoided for the same reason. For these reasons, it is desirable to conduct the reaction in an inert atmosphere, preferably a nitrogen atmosphere, and in the presence of a solvent such as toluene, benzene, tetrahydrofuran, methylene chloride, chloroform, ether, or the like. These solvents can all be described as organic aprotic solvents. All of them have in common the fact that they will dissolve the alkylating agent which is subsequently added as hereinafter explained.
The reaction temperature does not appear to be a critical factor, and the reaction may be run at temperatures of from -78° C. to 0° C. and even up to room temperature. The reaction seems to go to completion rather quickly and so reaction time is not a factor. Generally, however, four to eight hours assures substantially complete reaction.
In every instance, unless hereinafter specified to the contrary, it is preferred for overall reaction synthesis efficiency that the amount of ingredients be reaction equivalent amounts. It should, however, be understood that more or less may be employed if desired, but for overall process efficiencies, since the reactions are generally addition reactions, equivalent amounts are most desirable.
The addition of the naphthoquinone and the alkoxy furan, provides the following addition structure which forms the basic carbon skeleton of the desired antibiotics. ##STR3##
Simultaneously with the formation of this first synthesis intermediate, the product is alkylated in the presence of a base to protect the 1,4 position keto groups of said naphthoquinone. This alkylation is a well known procedure and need not be described with great particularity herein. It can generally be described as a Williamson-ether synthesis. The purpose of the alkylating agent is to protect the quinone dione groups by adding protective blocking groups thereto, thus preserving the desired structure.
The alkylation must be conducted under basic conditions in order for it to go and generally this can be accomplished by conducting the reaction in the presence of sodium carbonate or potassium carbonate. The addition of base is important, as hereinafter explained, in order to make sure that the product is tautormerized to the hydroquinone derivative, synthesis intermediate.
The amount of base can be from 2 to 4 equivalents.
The Williamson-ether alkylation can be conveniently accomplished by solvent removal and then adding directly to the reaction vessel for the first step herein described, a suitable alkylating agent such as dimethyl sulfate, while refluxing with anhydrous acetone. The result is formation of a second synthesis intermediate with the methylating protective groups having the following formula: ##STR4## Summarizing for a moment, it can be seen that in the overall basic reaction step herein described as the "first step", in fact there are three separate reactions which occur. In the first instance, the 1,4 naphthoquinone reacts with the alkoxy furan, the product tautomerizes in the presence of a base to hereinbefore described first synthesis intermediate whose formula has been shown. And, when conventional Williamson-ether synthesis alkylating agents such as dimethyl sulfate in boiling acetone are added in the presence of base, methylation occurs at the phenolic positions to provide methyl protecting or blocking groups, and the second synthesis intermediate herein described.
In actual practice, the addition reaction, the tautomerization and the addition of the protecting alkylating groups such as methyl groups, all occur in the same reaction vessel, as will be apparent from the examples hereinbelow. It is for this reason that although three different chemical reaction steps occur, each of these have been described as forming a part of the first reaction step of the synthesis.
The product of this first reaction step, whose formula has previously been given, for purposes of succinctness, is described as the second synthesis intermediate. It is a bright red oil and may be easily separated by filtering from the solvent and other reactants of the first step.
This second synthesis intermediate is then hydride reduced to reduce the functional groups of the two position moiety, that is, "A" to alcoholic functional groups. It has heretofore been mentioned that "A" may be a keto group, an ester group, an aldehyde group, or a nitrile group. These are now hydride reduced so that whatever functional groups are represented by "A", are reduced to a hydroxyl containing moiety. This reduction is necessary so that cyclization may occur in a reaction step which is described hereinafter.
Hydride reduction is well known. Suitable reducing agents which may be employed are sodium borohydride and lithium aluminum hydride. If "A" represents an ester moiety, lithium aluminum hydride must be employed as the reducing agent. In fact, lithium aluminum hydride is the preferred reducing agent for all of the hydride reductions which occur.
In the hydride reduction step, the reducing agent, such as lithium aluminum hydride, in ether, again under anhydrous conditions, is added to the heretofore described bright red oil synthesis intermediate, in order to reduce the "A" substituent to an alcoholic moiety. Again, it is preferred that equal molar amounts be employed. As is well known, the reaction must be anhydrous to prevent reaction between the water and the hydride reducing agent. Pressure is not a factor. While it is preferred that ether be employed as the solvent, other solvents such as tetrahydrofuran or glyme may be employed. The reaction may be run at temperatures from -78° C. up to 0° C., or even higher to room temperature. The product of this reaction, assuming that "A" represents an acetyl group, may be represented by the following structural formula: ##STR5##
This second synthesis intermediate, with the reduced alcoholic group, is a pale yellow oil and filtration and evaporation of the solvent may be used for separation of the same.
After separation of this pale yellow oil intermediate, the next step of the process involves removal of the alkyl portion of the alkoxy furan with a deblocking agent and internal cyclization in order to provide ring formation between the two position alcoholic moiety of the naphthoquinone ring structure and the alkoxyfuran.
These functions are accomplished by use of a deblocking agent and an internal cyclization agent. The terms "deblocking agent" and "cyclization agent" are well known to organic synthesis chemists, and readily understood. They define the function of the chemical employed. For further details see Reagents for Organic Synthesis, Fieser and Fieser, Vols. 1-6, which is incorporated herein by reference. While the precise agents mentioned hereinafter are preferred, others performing the same function can also be employed.
The preferred deblocking agent is trifluoroacetic acid in methylene chloride but others such as paratolulene sulfonic acid or naphthalene sulfonic acid may be equally satisfactorily employed.
The preferred internal cyclization agent is diaza bicyclononane, however others such as triethylamine, diazabicycloundecane or diazabicyclooctane can be employed. The common factor being with these cyclization agents that they are all Lewis bases and might be termed non-nucleophilic bases.
With respect to this reaction wherein the ring formation by internal cyclization occurs as well as along with deblocking of the alkoxy group, anhydrous conditions must be employed and the reaction must be conducted in a solvent such as chloroform, toluene or ether. Temperature does not appear to be an important reaction factor.
The reaction product, again assuming that "A" represented an acetoxy group, can be represented by the following formula: ##STR6##
In the final step of the reaction process, oxidative dealkylation to remove the blocking CH 3 groups is employed. One oxidative dealkylation which can be employed is known as a Rapoport's procedure. For details of such a procedure, see C. D. Snyder and H. Rapoport, Journal American Chemical Society, Vol. 94, page 227 (1972) which is incorporated herein by reference. In this reaction, silver oxide in the presence of nitric acid may be employed for oxidative demethylation. However, a suitable alternative is nitric acid in acetic acid. Since the Rapoport oxidative demethylzation procedure is known and described in the incorporated by reference Journal article, details will not be given herein, except in the specific working examples.
In the final reaction step, the CH 3 O groups are reconverted to diones, and assuming that in the initial reaction step "R" equals hydrogen, "A" equals CH 3 CO, the product of the reaction would be deoxykalafungin, which has the following formula: ##STR7##
If the "R" hydrogen moiety as shown was replaced with an OH group, the product is kalafungin.
In repeating several different runs of the reaction, an overall reaction yield as measured from starting materials to the final deoxykalafungin product, has been as high as 17%. This yield for complex syntheses as shown herein is considered extremely good.
The following examples are shown to further illustrate, but not limit, the process of this invention.
EXAMPLES
The following general information should be noted. Diethyl ether and tetrahydrofuran were distilled from lithium aluminum hydride. All organic extracts were dried over Na 2 SO 4 . Melting points were determined on a Fisher-Johns melting point apparatus and are uncorrected. Infrared spectra were determined on a Beckman IR-4250 spectrometer. Nuclear magnetic resonance spectra were determined on a Varian EM-360 instrument in CDCl 3 with absorptions recorded in ppm downfield from internal Me 4 Si. Ultraviolet spectra were recorded using a Cary Model 14 spectrometer. High resolution mass spectra were recorded on an AEI MS-902 high-resolution mass spectrometer. Elemental ayalyses were performed by Galbraith Laboratories, Inc.
To a 1.0 M toluene solution of 2-acetyl-1,4-naphthoquinone (340 mg. 1.7 mmol) at -78° C. under nitrogen was added via syringe a 1.0 M toluene solution of 2-tertbutoxyfuran (250 mg. 1.8 mmol). The resoluting solution was allowed to warm slowly to room temperature. The solvent was removed under reduced pressure and replaced with 15 mL of anhydrous acetone. Potassium carbonate (730 mg, 5.3 mmol) and dimethyl sulfate (500 mg, 4.0 mmol) were added, and the solution was heated at reflux for 8 hours. The cooled solution was filtered and the filtrate was concentrated. Silica gel chromatology (10:1 hexane-ether) yielded 390 mg (62%) of a bright red oil: IR (film) 1610, 1387, 1145 cm; NMR (CDCl 3 ) 1.42 (s, 9H), 2.53 (x, 3H), 3.80 (s, 3H), 3.94 (s, 3 H), 5.63 (d, 1H, J=3 Hz), 6.85 (d, 1 H, J=3 Hz), 7.56 (m, 2H), 8.15 (m, 2 H). High-resolution mass spectrum for C 22 H 24 O 5 required m/e 368.16238; found m/e 368.16171.
To a stirred solution of lithium aluminum hydride (20 mg, 0.50 mmol) in ether (1.0 mL) at -10° C. under N 2 was added the red oil, 1,4-dimethoxy-2-acetyl-3-(5-tertbutoxy-2-furyl) naphthalene, (390 mg. 1.06 mmol) in (1.0 mL of ether. The solution was stirred for 30 minutes at -10° C. and then quenched by slow addition of 5 drops of water, 5 drops of 1 N NaOH, and then 1 mL of H 2 O. After stirring for a further five minutes, the solution was filtered, diluted with ether, and dried. Filtration and evaporation of the solvent yielded 350 mg (96%) of a pale yellow oil; IR (film) 3450, 2980, 2850, 775 cm; NMR (CDCl 3 ) 1.41 (s, 9 H), 1.56 (d, 3 H, J=7 Hz), 3.67 (s, 3 H), 4.06 (s, 3 H), 4.18 (br s, 1H) 4.35 (q, 1H, J=7 Hz), 5.64 (d, 1 H, J=3 Hz), 6.43 (d, 1H, J=3 Hz), 7.52 (m, 2H), 8.13 (m, 2H). High resolution mass spectrum for C 22 H 26 O 5 required m/e 370.17803; found m/e 370.17909.
To a 0.5 M methylene chloride solution of the pale yellow oil, 1,4-dimethoxy-2-(d-hydroxyethyl)-3-(5-tert-butoxy-2-furyl)-napthalene (310 mg, 0.84 mmol) at 0° C. under N 2 was added 1 equivalent of trifluoroacetic acid deblocking agent. The ice bath was removed and the solution stirred for 30 minutes. Benzene was added (5 mL), and the solvents were removed at reduced pressure (repeated three times). The material remaining was dissolved in 4 mL of dry benzene, and 1 equivalent of diazabicyclononane cyclization agent was added. After stirring for 30 minutes at room temperature, the solution was diluted with 20 mL of 1:1 benzene-ether and washed with 5 mL of 0.5 M HCl and then brine. The organic layer was dried and filtered, and the solvent was removed at reduced pressure. Silica gel chromatography (hexane-EtOAc) yielded 90 mg (35%) synthesis intermediate, as colorless crystals. NMR data showed this material to be a 3:1 mixture of epimers about C- 1:IR (major) 1780 cm; NMR (CDCl 3 ) (major) 1.50 (d, 3H, J=7 Hz), 2.57 (d, 1H, J=18 Hz), 3.02 (dd, 1 H, J=18.45 Hz), 3.93 (s, 3H), 4.08 (s, 3H), 4.72 (dt, 1H, J=4.5, 3.0 Hz), 5.37 (q, 1H, J=7 Hz), 5.58 (d, 1H, J=3 Hz), 7.54 (m, 2H), 8.05 (m, 2H), Anal. Calcd. for C 18 H 18 O 5 ; C, 68.78, H, 5.77. Found: C, 68.57; H, 5.79.
To the synthesis intermediate having the blocked methyl groups, whose formula is shown in the specification at page 10, (68 mg, 0.216 mmol) and argenic oxide (110 mg, 0.9 mmol) in 2.0 mL of THF was added 0.2 mL of 6 N HNO 3 . This is Rapoport's Procedure of oxidative demethylation. After this disappearance of the argenic oxide (approximately 5 minutes), the reaction was terminated by addition of 10 mL of 4:1 CHCl 3 --H 2 O The mixture was diluted with CHCl 3 and washed twice with water and once with brine. The organic layer was dried and filtered, and the solvent was removed in reduced pressure. Recrystallization from ether yielded 58 mg (95%) of orange crystals; mp 181°-183° C.; IR (Nujol) 1780, 1660 cm; NMR (CDCl 3 ) 1.56 (d, 3H, J=7 Hz), 2.65 (d, 1H, J=18 Hz), 3.10 (dd, 1 H, J=18, 4.5 Hz), 4.78 (dt, 1H, J=4.5,3 Hz), 5.13 (q, 1H, J=7 Hz), 5.39 (d, 1H, J=3 Hz), 7.87 (m, 2H), 8.22 (m, 2H); UV (CHCl 3 ), 241, 248, 255, 267 sh, 345 nm, Anal. Calcd for C 16 H 12 O 5 ; C, 67.40; H, 4.26, Found: C, 67.40; H, 4.34.
The overall yield of 9-deoxykalafungin was 17%.
Similar reactions have been conducted wherein R equals OCH 3 and the naturally occurring product kalafungin prepared. Additionally, similar product has been prepared for R is an acetoxy group.
Reaction has also been run where R' is tertiarybutyldimethylsiloxy.
As heretofore mentioned, the 9-deoxykalafungin prepared in accordance with the process of this invention is a novel compound. A comparison of its inhibitory effects on certain micro-organisms and fungi, with the known compound kalafungin is enclosed.
______________________________________ Minimum Inhibitory Concentration (ug/ml) Deoxy-Test Organisms Kalafungin kalafungin______________________________________Nocardia asteroides UC 2052 3.9 3.9Blastomyces dermatitidis UC 1466 ≦1.0 ≦1.0Geotrichum sp. UC 1207 3.9 3.9Hormodendrum compactum UC 1222 3.9 2.0Phialophora verrucosa UC 1807 ≦1.0 ≦0.5Cryptococcus neoformans UC 4869 2.0 2.0Cryptococcus neoformans UC 1139 ≧1.0 1.0Sporotrichum schenckii UC 1364 15.6 7.8Monosporium apiospermum UC 1248 ≦1.0 1.0Candida albicans UC 7163 7.8 7.8Candida albicans UC 7164 7.8 15.6Microsporum canis UC 1395 7.8 7.8Trichophyton rubrum UC 1458 ≦1.0 ≦0.5Trichophyton violaceum UC 1459 2.0 ≦0.5Trichophyton asteroides UC 4775 2.0 1.0Trichophyton mentagro- phytes UC 4797 3.9 2.0Trichophyton mentagro- phytes UC 4860 2.0 1.0______________________________________
It can therefore be seen that deoxykalafungin is a potent inhibitor of a wide variety of pathogenic fungi. Indeed, in many instances, it has greater minimum inhibitory concentrations than does kalafungin.
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An efficient synthesis of quinone pyrano-gamma-lactone antibiotics such as kalafungin and the new compound 9-deoxykalafungin in four basic steps from readily available starting materials. The key step in which all of the carbon atoms present in the target molecule are assembled is the addition of an alkoxy furan to a two position functionally substituted 1,4 naphthoquinone. This is followed by alkylating to provide protecting groups, hydride reduction, removal of the protecting groups, internal cyclization and by oxidative dealkylation to provide practical overall yields of the desired antibiotics.
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FIELD
[0001] This patent specification is in the field of x-ray imaging of the breast and, more specifically, obtaining and processing x-ray data for tomosynthesis.
BACKGROUND
[0002] Breast cancer remains an important threat to women's health. X-ray mammography currently is the most widely used breast imaging tool for early detection, and is the modality approved by the Food and Drug Administration to screen for breast cancer in women who do not show symptoms of breast disease. A typical mammography system takes a projection image of the compressed breast, using a collimated x-ray source at one side and a film/screen unit at the other side of the breast. In the United States, typically two views are taken of each breast, one from above (cranial-caudal, or CC) and one from the side (mediolateral-oblique, or MLO). The x-ray source is an x-ray tube typically operating at 25-40 kVp, using a molybdenum or rhodium rotating anode with a focal spot of about 0.3-0.4 mm and, in some cases, 0.1 mm or less. An anti-scatter grid between the breast and the film/screen unit reduces the effects of x-ray scatter. The screen converts x-ray energy to visible light to which the film is exposed to record the image. In each view, the breast is compressed to reduce patient motion and also for reasons such as reducing scatter, separating overlapping structures in the breast, making the thickness of the imaged breast more uniform, and providing more uniform x-ray exposure. Currently, flat panel array receptors are replacing the film/screen units in mammography systems. The Selenia™ digital mammography system with such a flat panel x-ray receptor is offered by Lorad, a subsidiary of the assignee Hologic, Inc. of Bedford, Mass. Digital mammography has significant advantages and in time may fully supplant film/screen systems. Additional information regarding digital mammography systems and processes offered by the common assignee can be found at <www.hologic.com>.
[0003] Mammograms, whether from film/screen units or from digital systems, are particularly difficult to read, and the rate of false negatives and false positives is significant. Many advances have been made in recent years in image acquisition and in image processing, but a need still remains to reduce the rates of false negatives and positives, at least in screening mammography. Additional information can be gained through modalities such as CT and MRI, but examination and interpretation time and cost and other factors have limited their use in screening for breast cancer. Ultrasound breast examination has been proposed as an adjunct to x-ray examination, with synthesized ultrasound images of thick slices of the breast as they would appear in the same projection view as an x-ray view displayed together with the x-ray view, and a unit taking both x-ray and ultrasound images has been proposed. See, e.g., Patent Application Publication No. U.S. 2003/0007598 A1 and U.S. Pat. No. 5,983,123. Digital tomosynthesis has been proposed for x-ray breast imaging, and a laboratory unit is believed to have been installed at the Massachusetts General Hospital (more than a year before the filing date hereof), as reported in Wu, Tao, 2002, Three - Dimensional Mammography Reconstruction Using Low Dose Projection Images , PhD thesis, Brandeis University, incorporated here by reference. See, also, Patent Application Publication No. 2001/0038681 A1 and PCT application International Publication No. WO 03/020114 A2 published Mar. 13, 2003, both incorporated herein by reference. Digital tomosynthesis in more general contexts also has been proposed. See, e.g., U.S. Pat. Nos. 6,289,235 and 5,051,904, commonly assigned U.S. Pat. No. 4,496,557, and Digital Clinical Reports, Tomosynthesis. GE Brochure 98-5493, 11/98, all incorporated herein by reference. Reference markers can be used in x-ray imaging for purposes such as checking the rotation angle and unwanted shift of center of rotation of an x-ray source and receptor, and fiducial phantoms can be used in 3D angiography to calibrate for irregular scan geometries. See, e.g., U.S. Pat. Nos. 5,051,904, 5,359,637, and 6,289,235, N. Navab, et al., Dynamic geometrical calibration for 3 D cerebral angiography, SPIE Vol. 2708, pp. 361-370, and said PCT published application WO 03/020114 A2, all incorporated by reference here.
[0004] It is believed that no breast tomosynthesis systems are commercially available currently for clinical use in breast imaging, and that improvements in x-ray imaging and tomosynthesis are a desired goal. Accordingly, it is believed that a need remains for improved and practical tomosynthesis mammography.
SUMMARY
[0005] In a typical x-ray imaging according to preferred embodiments disclosed in this patent specification, a patient's breast is immobilized, at the same or lower compression than in conventional mammography, between a breast platform and a compression paddle. The platform and paddle, and the breast between them, in turn are between an x-ray source and a digital imaging receptor. Unlike conventional x-ray mammography, in which typically a breast is imaged from only one angle at a given compression, here the immobilized breast is imaged with x-rays from the source that pass through the breast and impinge on the receptor, from a greater number of different positions of the source and receptor relative to the breast while maintaining the breast immobilized, to derive image data for the respective positions. To do this, the x-ray source moves around the immobilized breast, typically but not necessarily in an arc, and the receptor also moves relative to the breast, but in a motion that allows it to remain substantially parallel to the same plane. The x-ray data taken at each of a number of positions of the receptor relative to the breast is processed to form images where each of a number of the images is formed from image data acquired from two or more of the different positions, e.g., to form tomosynthetic images. The x-ray dose to the breast can be different for the different imaging positions. One or more of the imaging positions can use an x-ray dose comparable to that used for conventional mammography. These positions may be the same or similar to the source/receptor positions for the typical views used in conventional mammography, e.g., the CC view and the MLO view. Fiducial markers can be used to help assess the positions of the x-ray source and x-ray receptor relative to each other and/or the breast being imaged, and for other calibration purposes. The fiducial markers can be integrated with the compression paddle and/or the breast platform, or can be positioned otherwise to serve the intended purpose. The immobilized breast can be imaged at angular positions extending over a selected range around the immobilized breast, for example ±15°, although other ranges can be used in other examples. The motion can be continuous over some or all of the imaging positions, or can be intermittent such that the x-ray source and/or the x-ray receptor stop for taking and image and then move to the next position for the next image.
[0006] An antiscatter grid can be used, positioned between the breast platform and the x-ray receptor while x-ray image data are taken. One example is the grid available from Lorad under the tradename HTC® grid. Alternatively, the image data at some or all of the imaging positions can be taken without an antiscatter grid that is external to the x-ray receptor. Rather than using the currently conventional materials for the x-ray emitting target in an x-ray tube serving as the x-ray source, in one of the preferred embodiments the target is made essentially of Tungsten, to provide x-rays at energies that are believed more suitable for breast x-ray tomosynthesis. Geometries other than an x-ray source that rotates around the immobilized breast and an x-ray receptor that moves relative to the breast and the source but remains in substantially parallel to the same plane, can be used.
[0007] Image data taken at the different imaging positions can be processed to generate tomosynthetic images of selected slices of the breast. The images can be of thin slices, essentially planar sections through the breast, as in CT slices. Alternatively, they can be of thick slices of the breast, e.g., slices that are about 0.5 cm to about 1.0 cm thick, and simulate projection images of slices of that thickness, projected on one or more selected image planes. In one example, the image plane or planes of the thick slice images are the same as those of the typical conventional mammograms, and can be displayed for viewing in appropriate groupings. For example, projection-like tomosynthetic images of thick slices on a plane parallel to that of a conventional CC image can be displayed together with a conventional CC image of a breast, on the same screen or adjacent screens or other displays. Similarly, projection-like tomosynthetic images of thick slices on plane parallel to that of an MLO image can be displayed on the same display or on adjacent displays with a conventional MLO mammogram of the same breast. In the alternative, the image planes of the tomosynthetic images can be at one or more selected angles to the image planes of the typical images used in screening x-ray mammography.
[0008] Tomosynthetic images can be formed using a form of filtered backprojection modified by using a filter function that is significantly different from a conventional ramp filter used in CT technology backprojection. The novel filter function is believed to be uniquely suited to breast tomosynthesis. In particular, in the frequency domain the novel filter function at low spatial frequencies is much steeper than a CT technology ramp function, it is close to an all-pass filter at intermediate frequencies, and at higher frequencies it falls off to suppress fine detail noise.
BRIEF DESCRIPTION OF THE DRAWING
[0009] FIG. 1 illustrates schematically a front view of an x-ray source, a breast immobilized between a compression paddle and a breast platform, an antiscatter grid and an image receptor, where the x-ray source and the x-ray receptor move relative to the breast for imaging the breast at different angles according to a preferred embodiment.
[0010] FIG. 2 illustrates a side view of the system illustrated in FIG. 1 and additional components of a system according to a preferred embodiment.
[0011] FIG. 3 illustrates a display arrangement showing both images that are the same or similar to conventional mammograms and tomosynthetic images according to a preferred embodiment.
[0012] FIG. 4 illustrates in graph form a backprojection filter in the frequency domain used in a preferred embodiment, compared with a conventional ramp filter used in CT technology and an all-pass filter.
[0013] FIG. 5 illustrates coordinate values of a backprojection filter according to a preferred embodiment as control point values in the frequency domain in log scale.
[0014] FIG. 6 illustrates the use of fiducial markers.
[0015] FIGS. 7 and 8 are similar to FIGS. 1 and 2 , respectively, but illustrate another preferred embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] FIG. 1 schematically illustrates in front view an x-ray source 100 in three different positions 100 a , 100 b and 100 c , between which source 100 moves in an arc centered at the top center of a patient's breast 102 immobilized between a compression paddle 104 and a breast platform 106 . An antiscatter grid 108 is immediately below breast platform 106 , and an x-ray receptor 110 is below grid 108 , and is shown in three different positions, 110 a , 110 b , and 110 c , corresponding to the illustrated positions of source 100 . Receptor 110 moves relative to immobilized breast 102 along a path substantially parallel to breast platform 106 and maintains substantially the same distance from platform 106 , as indicated by the arrows in FIG. 1 . In operation, source 100 moves from one of its illustrated position to another, and so does receptor 110 . At each position of source 100 and receptor 110 , source 100 is energized to emit a collimated x-ray beam, of which only the center ray is illustrated. The beam irradiates breast 102 and some of the radiation that has passed through the breast also passes through grid 108 and is received by receptor 110 . As in known in the art, receptor 110 and associated electronics generate image data in digital form for each pixel of a rectangular grid of pixels at each of the illustrated angular position of source 100 and translation positions of receptor 110 relative to immobilized breast 102 . While only three positions are illustrated in FIG. 1 , in practice image data is taken at each of a much greater number of positions, for example, at every 1° of an arc of ±15° of source 100 around immobilized breast 102 . The taking of image data can be while source 100 and receptor 110 are stopped at their respective positions, after moving from one position to the next. In a different preferred embodiment, the motion of one or both of source 100 and receptor 110 can be continuous, with a respective set of image data being accumulated over a small increment of continuous motion, say a 0.1° to 0.5° arc of motion of source 100 . These parameters are only an example. Different preferred embodiments can use different ranges of motion of source 100 and receptor 110 , and can use a motion of source 100 that is arcuate and centered at a different point, such as in immobilized breast 102 or at breast platform 106 or at grid 108 or at receptor 110 , or a motion that is not arcuate but is translational or is a combination of different types of motions, such as partly translational and partly rotational. In the most preferred embodiment, the source 100 motion is arcuate and the receptor 110 motion is translational. As described further below, in practice source 100 can be integrated in a C-arm that is the same or similar to the C-arm used in the commercially available Selenia® or MIV mammography systems available from Lorad, and receptor 110 can be the same receptor as used in such commercially available systems but mounted differently so that it translates in a plane substantially parallel to breast platform 106 while maintaining a substantially constant distance from platform 106 rather that rotating as a unit with source 100 , as in Lorad commercially available systems.
[0017] FIG. 2 schematically illustrates a side view of a mammography system using the arrangement of FIG. 1 . In FIG. 2 , x-ray source 100 is at one end 200 a of a C-arm 200 that is supported for selective rotation about an axis 202 , independently of a support 204 for compression paddle 104 and breast platform 106 . Support 204 also selectively rotates about the same axis 202 . The other end 200 b of C-arm 200 interacts with x-ray receptor 110 through a motion translator schematically illustrated at 206 that translates the rotational motion of the end 200 b about axis 202 to a substantially translational motion of receptor 110 that substantially maintains the distance of receptor 110 from breast platform 106 while x-ray data is being taken. FIG. 2 is not to scale, and receptor 110 can be spaced further from member 200 b than illustrated, to allow more space for motion translator 206 , and also to allow for receptor 110 to be moved selectively further from or closer to breast platform 104 and thus allow for x-ray image magnification. In operation, C-arm 200 and support 204 are rotated to desired angular positions, either manually or by motor drives, patient breast 102 is positioned on platform 106 and is immobilized by bringing paddle 104 toward platform 106 and compressing breast 102 , with typically the same or less force than for a typical conventional mammogram, such as between one to one-third the conventional force. With breast 102 immobilized, and with C-arm at a selected angle relative to a normal to platform 106 and receptor 110 , such as +15°, imaging starts, and a projection image is taken for each of a number of selected angular positions of source 100 while C-arm 200 rotates, continuously or intermittently, through a selected angle, such as an angle of 30°, is from +15° to −15°. Of course, the motion can be in the opposite direction, from −15° to +15°, or can be over a different angular interval, such as over less than a total of 30°, e.g. 25°, 20°, etc., or more than 30°, such as 35°, 40°, etc. Currently, the preferred range is ±15°. A set of image data can be taken at selected angular positions, such as every degree, or every fraction of a degree, or every several degrees of angle. The angular increments between the different positions for sets of image data need not be the same. For example, the increments around 0° can be less than those at the extremes of the angular positions, or vice versa. Currently, the preferred angular increment is 3°. The sets of image data can be taken after an incremental motion from one angular position of source 100 to another, and from one translational position of receptor 110 to another, such that source 100 and receptor 110 are stationary while a set of image data is being taken. Alternatively, one or both of source 100 and receptor 110 can move continuously while sets of image data are being taken, one set for each increment of continuous motion. In the currently preferred embodiment, in the example of continuous motion while taking image data both source 100 and receptor 110 move while image data are being taken.
[0018] FIG. 2 also illustrates schematically an electrical/electronic system 208 that interacts with the components discussed above. System 208 includes a control 210 for selectively energizing and otherwise controlling x-ray source 100 , an arm rotation control 212 for selectively rotating C-arm 200 and support 204 , a breast compression control 214 for selectively moving compression paddle 104 toward and away from breast platform 106 , data readout electronics 216 coupled with x-ray receptor 110 to read out the sets of image data at the respective positions of source 100 and receptor 110 relative to immobilized breast 102 , and an image reconstruction and display unit 218 coupled with data readout electronics 216 to receive the sets of image data from electronics 216 and to process the image data for reconstruction and other purposes and display images.
[0019] For a given position of breast 102 , such as a position that is the same or similar to the CC position for a conventional mammogram, source 100 and receptor 110 can be positioned relative to immobilized breast 102 such that at the 0° position a center ray of the x-ray beam from source 100 would be substantially normal to receptor breast platform 106 and receptor 110 . For a first set of image data, source 100 is at + (or −) 15° in a preferred example, and is gradually moved, continuously or intermittently to − (or +) 15°, with a set of image data taken every 3°. The angular range and the increment over which data sets are taken can each be selectively set by the operator, depending of characteristics of the breast being imaged and the screening and diagnostic needs, and can be different for different patients or from one to the other breast of the same patient. For example the source can move through angles that range from a fraction to a degree to several degrees from one imaging position to the next. Each set of image data is supplied by image readout 216 for processing at image reconstruction and display unit 218 . Each set of image data can be taken at the same x-ray dose to the breast, and the dose at any one of the different imaging positions can be substantially less than that for a conventional mammogram. The x-ray dose can be substantially the same for each imaging position, but preferably the dose at one of the position, e.g., at or close to the 0° position, is the same or similar to dose for a conventional mammogram while the dose at the each of the other positions is less, preferably much less. Alternatively, the scan can begin with or end with an exposure close to the 0° position at a dose similar to a conventional mammogram, and the rest of the set of image data can be over the angular range with each exposure at an x-ray dose that is substantially less than that for a conventional mammogram. Thus, two types of images can be produced in accordance with the currently preferred embodiment while breast 102 is immobilized in the same position. One type is the same or is at least similar to a conventional mammogram, which can be read and interpreted in the manner familiar to health professionals. The other type is tomosynthetic images reconstructed from the image data and displayed either separately or as an adjunct to the display of the image that is the same or similar to a conventional mammogram. The process described above for one position of breast 102 can be repeated for another position. For example one process can be for a breast position in a manner that is the same or similar to positioning the breast for a conventional CC view, the breast can then be released, the support 204 and C-arm 200 rotated to other angular positions and the breast repositioned in a manner that is the same and similar to the position for an MLO view, and the procedure repeated.
[0020] FIG. 3 illustrates schematically a display according to a preferred embodiment, where 300 is a display that is the same or similar to a display for a conventional CC mammogram of two breasts and 302 is a similar display for a conventional MLO view. Another display 304 is close to display 300 and can display any one or more of several types of tomosynthetic images reconstructed from the image data taken at the different imaging positions. For example, if display 300 shows views of a right breast taken at or close to the 0° position in one imaging sequence of a total rotation of source 100 over the ±15° range, display 304 can show, at the option of the user, any one or more of the following views of the right breast: (1) one or more of the projection views taken at the different imaging positions; (2) one or more of several tomosynthetic views of thick slices of the right breast simulating projection views of the right breast taken at the same or similar angle as the view at display 300 , with the slices having effective thicknesses selected by the user, such as from several mm to something less than the thickness of the immobilized breast, typically from several mm to about 1 cm; (3) one or more tomosynthetic views of thin slices of the right breast, each simulating a slice through the breast in a respective plane parallel to that of the view at display 300 , where each thin slice has an effective thickness of about a mm or less; (4) thin and/or thick slices corresponding to planes that are not parallel to that of the view at display 300 ; (5) a scrolling image through any of the slices discussed above; and (6) a selected combination of the above displays. A similar display 306 can be associated with display 302 , and show a similar selected views related to the images at display 302 . FIG. 3 illustrates only one example according to preferred embodiments. Other arrangements also are contemplated, such as different windows on the same display for the different images, differently positioned displays, etc. The user can select the type of images for display, the thickness of a thick slice or a thin slice, the orientation of the slices for display, which slices to display where and in what order, whether to display thick or thin slices as static slides or to scroll through slice images as in movie, etc. Controls 306 can be coupled to each of the displays, and can include manual inputs such as a joystick and/or other known interface devices and a suitably programmed computer to allow a user to control the images that are displayed. For example, the controls can include: (1) selecting one or more areas or volumes of interest at one or more of the displayed images and further processing the image data to form and display additional images of the area or volume of interest (for example, if a lesion is identified that is between tomosynthetic thin slices 32 and 37 , the user can manually designate the corresponding area or volume and command the display of the thin slices in that area or volume, and other parameters such as the orientation of the thin slices); (2) identifying the position of an area or region of interest for use in additional procedures such as needle biopsy (for example, the user can designate with a cursor or in some other way a point in or an outline of a suspected lesion in the breast, and the xyz coordinates of the designated point, area, or volume); (3) the user can manually designate the desired thickness, arrangement, and other parameters of slices whose images are to be displayed, to thereby display images of slices that have user-selected thicknesses and other parameters, such as orientation, so that images of slices of different thicknesses and/or orientations can be displayed concurrently; and (4) the user can point to an area of interest in one of the displayed images and the system can automatically display one or more markers at corresponding or at least related locations in one or more of the other images that are being concurrently displayed.
[0021] At each imaging position, receptor 100 generates respective digital values for the pixels in a two-dimensional array. In one example, receptor 110 has a rectangular array of approximately 4096 by 3328 pixels, with a pixel size of approximately 70 micrometers in each of the column and row directions. The image data of a set (for a respective imaging position) can be processed either at the full spatial resolution of receptor 110 , or at a lower effective spatial resolution, e.g., by binning several original pixel value's into a single, combined pixel value. For example, each set of 2×2 adjacent pixels can be combined into a single respective pixel value, thus achieving an effective spatial resolution of 140 micrometers in each direction. The binning can be in some other combination of original pixels, such as 2×3, and can be done by data readout electronics 216 or image reconstruction and display unit 218 ( FIG. 2 ).
[0022] Image reconstruction is done using backprojection in the spatial domain or in the frequency domain as in CT technology but with a novel filter that differs from the ramp filter (in the frequency domain) used in CT reconstruction. See, e.g., G. Lauritsch, et al., A theoretical framework for filtered backprojection in tomosynthesis , SPIE Medical Imaging Conference, Vol. 3338, 1998, and U.S. Pat. No. 6,442,288, both incorporated here by reference. Referring to FIG. 4 , the novel filter is represented by graph 400 , while a graph 402 represents a conventional CT ramp filter, and a graph 404 represents an all-pass filter. As seen in FIG. 4 , the novel filter according to a preferred embodiment rises sharply in amplitude at lower frequencies, between points a and c (in the range indicated at b), as compared with the conventional ramp filter, then levels off at intermediate frequencies to become the same as or close to an all-pass filter between points c and d, and then gradually drops off at higher frequencies. Using the novel filter produces significantly better breast images compared to using a conventional CT technology ramp filter.
[0023] FIG. 5 gives a sense of the values of the low, intermediate and high frequencies discussed in connection with FIG. 5 . In FIG. 5 , the frequency axis is plotted on log scale, and typically is related to spatial resolution of a few mm or more, i.e., it affects mainly to overall impression and flatness of the reconstructed image. With suitable suppression of low frequency content through frequency dependent weights defined by the shape of the novel filter, and gradual suppression of high frequency noise, a tomographic image with good image contrast at all frequency scales can be reconstructed and presented in accordance with a preferred embodiment. Preferably, the filtered backprojection reconstruction of tomographic images is carried out in the frequency domain, using well known processes with the novel filter. However, comparable filtered backprojection can be carried out in the spatial domain, as in known in CT technology, using direct convolution of image data with the spatial domain representation of the filter represented in the frequency domain in FIGS. 4 and 5 . In either the frequency domain or in the spatial domain the novel filter can be applier to the image data to generate filtered data for backprojection, or backprojection can be carried out first, followed by a filtering operation. The reconstruction process preferably uses the direct fan-beam backprojection method known in CT technology, but with the novel filter, although it may be possible to use the image data to simulate sets of parallel beam paths for backprojection. The reconstructed thin slice images form a three-dimensional image of the breast, comprising voxel values for respective incremental volumes. These voxel values can then be combined as known in CT technology to synthesize any selected thin slice or thick slice in any selected orientation, and in any selected projection plane.
[0024] In a preferred embodiment, while each of all or most of the imaging positions uses lower x-ray dose than that of a conventional mammogram, higher KV can be used as compared with a conventional mammogram in order to boost signal levels from receptor 110 and improve signal-to-noise (SNR) ratios. In addition, preferable an x-ray tube with a Tungsten target is used to further exploit the advantage of higher kVp imaging of the breast, such as between 25 and 50 kVp with different x-ray beam filtration. A small focal spot, of the order of 1 mm or less, is preferred, although a larger focal spot of several mm can be used.
[0025] In other preferred embodiments, contrast enhanced breast tomosynthesis can be carried out, by obtaining tomosynthetic images as described above before injecting a contrast agent such as Iodine into the patient, then repeating the process after injection, and subtracting images of the pre-injection and post-injection sets. Another preferred embodiment involves time subtraction tomosynthesis, related to subtracting comparable images obtained at different times. Yet another is dual-energy breast tomosynthesis, whereby two tomosynthetic images at low and high energies are acquired and then subtracted, the two images being acquired through a process such as using successive scans at two different x-ray energy ranges or by alternating x-ray pulses of low and high energy to create the two images. Another other preferred embodiment involves obtaining and displaying both x-ray tomosynthetic images of a breast and ultrasound images of the same breast. Computer aided diagnosis, as known to those skilled in the art and as commercially used currently in the United States, can be applied to selected tomosynthetic images generated as described above.
[0026] Fiducial markers are used in preferred embodiments for off-line (without a breast) mechanical positioning and calibration and/or on-line (while imaging a breast with x-rays) image based positioning encoding of moving components. The fiducial markers can be made of a material such as lead or another metal, and can be in the form of points or lines or arrows or crosses, at locations that would be imaged by the x-ray beam at receptor 110 simultaneously with the imaging of a breast 102 but outside the area of the breast image. The fiducial markers are integrated with compression paddle 104 , or they can be at or near breast platform 106 , or they can be supported separately from paddle 104 , for example on a separate member that can be selectively brought into the path of the imaging x-ray beam or taken out of that path, e.g., to take an image that is the same or similar to a conventional mammogram. Different patterns or types of fiducial markers can be provided, for selection by the user. FIG. 6 illustrates an example of arranging fiducial markers 601 , 602 , 603 and 604 relative to an image of breast 102 a on receptor 110 , as seen in a top plan view when receptor 110 is horizontal and the fiducial markers are integrated in compression paddle 104 .
[0027] An alternative embodiment, illustrated schematically in a front view in FIG. 7 and in side view in FIG. 8 , is similar to the embodiment illustrated in FIGS. 1 and 2 except that receptor 110 is affixed to the end 200 b of C-arm 200 that is opposite x-ray source 100 . In this embodiment, receptor 110 moves relative to immobilized breast 102 along an arcuate path from one imaging position to another. Because the change in angle between receptor 110 and breast platform is small, it can be disregarded in processing the sets of x-ray image data. Alternatively, a geometric correction known to those skilled in the art can be applied to each set of image data to convert it to interpolated pixel values that would correspond to those that would have been obtained if receptor 110 had been parallel to and at the same distance from platform 106 at all imaging positions. The so corrected sets of image data can then be used in filtered back projections as described above.
[0028] In each of the embodiments of FIGS. 1-2 and FIGS. 7-8 , antiscatter grid 108 may be selectively retractable, so that the user may take any selected set of x-ray image data with or without using grid 108 . As in known in the art, grid 108 can be made to move relative to the x-ray beam during the taking of a set of image data. Similarly, the distance between breast platform 106 and receptor 110 can be selectively changed to effect magnification of the breast image recorded at receptor 110 .
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A method and system for producing tomosynthetic images of a patient's breast. An x-ray source that delivers x-rays through a breast immobilized and compressed between a compression paddle and a breast platform and form an image at a digital x-ray receptor panel. Multiple x-ray images are taken as the x-ray source and the receptor move relative to the immobilized breast. In one preferred embodiment, the x-ray source travels from −15° to +15°. The source can travel in an arc around the breast while the receptor travels linearly while remaining parallel and at the same distance from the breast platform. The sets of x-ray image data taken at different angles are combined to form tomosynthetic images that can be viewed in different formats, alone or as an adjunct to conventional mammograms.
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PRIORITY CLAIM
The present application claims priority to UK Patent Application No. 01 302 06.6, entitled “Method And Apparatus For Acquiring Digital Microscope Images”, which application was filed on Dec. 18, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for acquiring digital microscope images, and more particularly to a method and apparatus for acquiring a digital image of a specimen, or part thereof, on a microscope slide, which is larger than the field of view of the microscope.
2. Description of the Related Art
The use of digital images of microscope specimens, which are typically displayed on a display screen, is becoming increasingly important in the field of diagnostic pathology. For example, digital images of a microscope specimen may be captured using a microscopy imaging system and the acquired digital image data may be assembled together to form a composite image of the specimen, and transmitted to local or remote locations for diagnosis by a pathologist. Thus, the acquisition of digital images of pathology specimens advantageously enables specimens to be viewed by consultant pathologists at remote locations.
Conventional methods for acquiring a digital image of a microscope specimen which is larger than a single field of view image involves acquiring separate, adjacent field of view digital images or image “tiles” and subsequently mosaicing (also known as montaging or tiling) the adjacent images to obtain an overall composite image of the specimen or part thereof.
For example, WO-A-98/39728 discloses a method and apparatus for acquiring and reconstructing contiguous specimen image tiles. The adjacent image tiles are obtained by computer-controlled positioning of the microscope stage, on which the microscope slide is placed, beneath the imaging system comprising microscope and digital camera. The stage is driven by stepper motors, under control of a computer, in steps to precisely position the stage for acquiring each image tile, contiguous with the preceding image tile. Since the image tiles are contiguous, the image tiles can be readily seamlessly matched or abutted together to form a composite image.
Similarly, in EP-A-0 994 433, in the name of the present applicant, a method of acquiring digital microscope images is disclosed in which adjacent image tiles similarly are obtained by stepwise imaging of the specimen.
Whilst such conventional methods of acquiring digital microscope images result in a high quality composite image of the specimen, the imaging process is time consuming, particularly if imaging of a complete specimen is performed using a medium or high power objective lens in the microscope. This is because the time taken to image the complete specimen is proportional to the number of image tiles in the complete specimen. The higher the magnifying power of the objective lens, the smaller the area of the specimen contained in the field of view, and the greater the number of image tiles.
Moreover, the time taken to acquire an individual image tile is subject to physical constraints. In particular, for each image tile it is necessary to perform the sequential steps of: i) moving the microscope stage to the correct position; ii) pausing to allow the microscope stage to come to rest; iii) if necessary, focusing the microscope, and iv) operating the camera to acquire the image. To prevent excessive vibration or jitter of the stage during the stepwise movement, which would lead to poor quality images, the velocity of movement in step i) and the duration of the pause in step ii) are constrained by the physical limitations of the stage so that the time taken cannot be reduced below a certain amount.
In view of these limitations, imaging of a complete specimen of say 20 mm by 20 mm at 40× magnification may take over an hour and could take five to six hours. This time delay in the image of the specimen becoming available for diagnosis by a pathologist is problematic. In addition, the use of the valuable resource of the imaging system for such a lengthy period of time for only a single specimen may be difficult to justify.
One way of addressing this problem is to limit the area of the specimen to be imaged at high magnification to only selected portions. By restricting the area to be imaged at high magnification, it is possible to reduce the amount of time needed to acquire the specimen images. However, the selection of appropriate areas must be done by a skilled pathologist. In particular, it is necessary for an expert to identify the most significant regions of the specimen, to be viewed at high magnification, in order to make an accurate diagnosis.
If the pathologist is local to the imaging system, then the pathologist can select the relevant areas for scanning. However, this process represents a poor use of the pathologist's time. In addition, if a remote pathologist is then consulted for a second opinion, the remote pathologist will not be able to view, at high magnification, areas of the specimen other than those selected by the local pathologist. This compromises the ability of the remote pathologist to make an accurate diagnosis, since he or she is reliant on the local pathologist having selected all the important areas of the specimen. Many consultant pathologists will be reluctant to give a diagnostic opinion based on the limited images selected by another pathologist, particularly if that pathologist is not know to him or her.
One way of avoiding this problem, suggested in WO-A-98/44446, is to allow the remote pathologist to select the areas of the specimen for scanning at high magnification. However, this solution has the disadvantage that there will be a further delay between the time the remote pathologist makes the selection and the time when high magnification images become available due to the time taken for the specimen area to be imaged.
The method disclosed in EP-A-0 994 433 involves scanning the complete specimen only at high magnification. This overcomes the problem of only selected areas of the specimen being available for viewing by a pathologist at high magnification. However, as explained above, the process of acquiring adjacent high magnification images by stepwise movement of the stage is time consuming.
It would therefore be desirable to provide a method and apparatus for acquiring digital images of a microscope specimen at high magnification more quickly than conventional methods.
SUMMARY OF THE INVENTION
In accordance with a first aspect, the present invention provides a method for acquiring image data representing a digital image of at least part of microscope specimen using an imaging system, the method comprising moving the specimen relative to the imaging system in a predetermined path, whilst capturing a plurality of magnified images of the specimen.
By acquiring field of view images whilst the microscope stage (and thus the specimen) is moving relative to the imaging system, in accordance with the present invention, it is possible to significantly reduce the imaging time for a complete specimen. The imaging system resource can therefore be used to image a greater number of specimens per day than would be imaged using conventional imaging techniques.
The predetermined path may comprise a series of sub-paths or portions along which imaging takes place, interconnected by a series of sub-paths or portions along which imaging does not take place. For example, in a preferred embodiment, the imaging portions of the determined path comprise a series of parallel rows, each portion beginning at a first end of the row, so that each row is interconnected by a non-imaging portion of the path that extends diagonally back along the row.
Preferably, the plurality of images are captured at periodic intervals. In a preferred embodiment, the time interval between capturing an image, and the velocity of movement of the specimen within the imaging system are chosen such that overlapping images are acquired.
In a preferred embodiment, the microscopy imaging system comprises a microscope, particularly an optical microscope, and associated image capturing device, particularly a digital camera. A motorised microscope stage, holding the microscope slide containing the specimen, is driven beneath the stationary microscope.
The speed and direction of movement of the microscope stage is computer-controlled and the time interval between taking images using the digital camera is synchronised with the movement so that images with a desired amount of overlap are acquired.
Preferably, the method further comprises processing the image data for the acquired plurality of digital images to obtain data representing a composite image of the specimen. In particular the overlapping images can be assembled together, and the duplicated data at the area of overlap removed, to form a composite image by digital image processing techniques during and/or after the imaging of the complete specimen has finished.
Preferably the image processing is performed by cross-correlation of two adjacent images, and the amount of overlap of the images is sufficient to enable the accurate cross-correlation. Typically the overlap of adjacent images is between 10% and 15%, preferably about 10% of the image or up to 100 pixels of the camera.
In a preferred embodiment, the cross correlation is performed in an area of image overlap determined according to the velocity of the stage at the time the images were acquired. By restricting the area of overlap considered during cross-correlation, the image alignment processing time can be kept to a minimum.
In accordance with a second aspect, the present invention provides a computer readable medium having a computer program for controlling a microscopy imaging system to carry out a method in accordance with the first aspect of the present invention.
In accordance with a third aspect, the present invention provides a microscopy imaging system configured to carry out a method in accordance with the first aspect of the present invention.
Other preferred features and advantages of the present invention will be apparent from the following description and accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a microscopy imaging system in accordance with an embodiment the present invention;
FIG. 2 is a flow diagram illustrating the method of image acquisitioning in accordance with a preferred embodiment the present invention;
FIG. 3A is a graph illustrating the velocity of the microscope stage during the acquisition of a row of overlapping images, and
FIG. 3B illustrates a specimen area of a microscope slide and the rows of acquired images, in accordance with a preferred embodiment of the present invention; and
FIG. 4 illustrates the margin of overlap of images used to assist in constructing a composite image of the specimen from the separate acquired images in accordance with the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates the digital imaging apparatus suitable for use in accordance with a preferred embodiment of the present invention. The imaging apparatus 1 comprises a microscope 3 having a motorised microscope stage 5 for holding a microscope slide 7 , and an optical subsystem 9 including an objective lens 11 and eyepiece 15 . An example of a suitable microscope is the Axioplan 2 imaging microscope available from Carl Zeiss of Germany, using an Apochromat objective lens. The stage may be any suitable motorised stage having the necessary positioning accuracy, for example the Proscan stage available from Prior Scientific Instruments Limited of Cambridge, UK.
The motorised stage 5 is driven under the control of a stage controller 17 , which controls the stage in response to instructions from computer 19 . The motorised stage 5 is typically driven only in the x- and y- directions. In addition, focusing of the microscope is controlled by a piezo-electric controller 21 which controls a focussing device 21 a which moves the objective lens 11 towards and away from the slide 7 , along the axis of the optical system 9 , to focus the microscope 3 , under control of computer 19 . A suitable piezo-electric focusing controller 21 is available from Physik Instrumente of Germany.
The imaging apparatus 1 additionally includes a digital camera 25 , preferably a high resolution CCD camera. In the preferred embodiment, camera 25 includes a square array of CCD sensors, for example about 1024×1024 pixels and of 24-bit colour. The individual pixels of the camera are preferably square. Examples of suitable digital cameras are the X003P Firewire camera available from Sony Corporation and the Hamamatsu Orca C4742SC camera. The skilled person will appreciate that in other embodiments a single line camera comprising a single line of CCD sensors or a TDI (Time Delay Integration) camera comprising about ten lines of CCD sensors can be employed.
The camera 25 is arranged to acquire images from the microscope 3 under control of computer 19 and to provide the acquired images to computer 19 for processing, as described below.
As the skilled person will appreciate, prior to acquiring the images of the specimen, in accordance with the method of the present invention described below, the imaging system is calibrated using conventional techniques. The calibration information is input to computer 19 and used to determine the distance between and number of overlapping images to be acquired for a given specimen area, and thus the optimum parameters used for driving the stage 5 and controlling the camera 25 .
The method of acquiring a digital image of a microscope specimen, or more particularly, data representing a digital image of a significant part of a specimen on a microscope slide, using the apparatus of FIG. 1 is illustrated generally in FIG. 2 .
At step 10 , the microscope slide 7 containing the specimen in a specimen area 8 thereof is placed on the microscope stage 5 . The stage 5 , with the slide 7 thereon, is then moved, typically under manual control, so that the starting position of the specimen area 8 to be imaged is in the field of view of the microscope, and the stage coordinates of the starting position are input to the computer. Similarly, the stage is then positioned so that the finishing position of the specimen area 8 to be imaged is in the field of view and the coordinates of the finishing position input to the computer. Computer 19 is then able to determine the path along which the stage 5 will be driven, between the starting position and the finishing position, during imaging of the complete specimen area 8 , as well as the optimum control parameters for moving the stage and for controlling the camera.
It should be noted that although the path along which the stage will be driven is typically a continuous path, imaging may only take place along certain sub-paths or portions (referred to herein as “imaging portions” of the determined path). These imaging portions of the path are interlinked by portions of the path along which no images are captured. The camera 25 is controlled, by computer 19 , to capture images whilst the stage is moving along the imaging portions of the determined path so that the images are obtained in a sequence that can be most readily processed and stored for providing a composite image of the complete specimen, as described below.
At step 20 , under control of the computer 19 , the stage 5 is then automatically positioned to the starting position, for example corresponding to one of the corners of the specimen area of the slide 7 , so that the first image is in the field of view of the microscope 3 . Typically this is the top left hand corner of the specimen area 8 as shown labelled IA in FIG. 3B . In other embodiments, the starting position may be elsewhere e.g. on the left hand side in the centre of the specimen area.
At step 30 , under control of computer 19 and stage controller 17 , the microscope stage 5 is driven along a first portion of the determined path, which, in this example, is a straight line, preferably along the x-direction and parallel to the top edge of the slide (it is assumed that the slide is aligned carefully on the microscope stage), so that the stage travels a distance corresponding to the complete width of the specimen area 8 . The velocity of movement of the stage 5 along the first, and each subsequent, imaging portion (row) of the determined path is illustrated in FIG. 3A , and is described in more detail below. At the same time, the shutter of the camera 25 is operated at a fast shutter speed at periodic intervals to acquire digital images, each image corresponding to the field of view of the microscope. Movement of the stage 5 and operation of the camera 25 continues until the stage comes to rest at the opposite end of the specimen area 8 , from the starting position, typically the top right hand corner of the specimen area labelled IN in FIG. 3B .
The camera 25 thus captures a row of images (e.g. row I in FIG. 3B ) of the specimen area 8 of the slide 7 , the row of images underlying the microscope during the movement of the stage 5 along the first portion of the determined path.
At step 40 , the camera 25 passes the acquired data for the row of captured images to the computer 19 for further processing as described below.
At step 50 , the computer 19 considers whether the imaging process is complete, that is, whether the coordinates of the stage are at the finishing position, and thus the complete specimen area 8 has been imaged. If the scan is not complete, the method returns to step 20 by moving the stage 5 , without performing imaging, to the starting position of the next imaging portion of the determined path, which in a preferred embodiment is the beginning of the next row of images (e.g. row II, starting at position IIA of FIG. 3B ). Thus the microscope stage 5 is positioned so that the field of view contains an image that is adjacent to, and contiguous with or slightly overlapping, the image acquired at the first position (IA) of the previous row of images. The method then continues by capturing the next row of images.
Once the computer 19 determines that the scan is complete, that is, the stage has reached the finishing position, and image data has been acquired for the complete specimen area, the method continues with step 60 .
At step 60 , the computer 19 processes the data for the acquired overlapping digital images to obtain processed data representing a single composite image of the complete specimen or part thereof. This is achieved conventionally by mosaicing techniques, well known in the art. Since, in the present invention, the individual images are overlapping, a cross-correlation algorithm is used to calculate the best alignment of the images with respect to each other. Further details of the preferred method of alignment of the images are set out below.
Once the images have been aligned for the complete specimen, data representing the final composite image is output at step 70 for storage in memory, preferably as a single image file.
It will be appreciated that steps 20 to 70 of the above-described method are preferably implemented in the form of one or more computer programs running on computer 19 . The computer program(s) may be provided on a computer readable medium such as an optical or magnetic disk which can be loaded in a disk drive of computer 19 . Alternatively, the computer readable medium may be a computer system carrying the website or other form of file server from which the computer program(s) may be downloaded to computer 19 over the Internet or other network.
FIG. 3A is a graph representing the velocity of the stage during the acquisition of images of the specimen on the microscope slide 7 . Ideally, the velocity of the stage should be at a constant optimum velocity V o throughout the acquisition of a row of images, so that the amount of overlap of adjacent images is substantially constant. As the skilled person will appreciate, the optimum velocity is dependent upon the operating characteristics of the camera. However, in the preferred embodiment, it is necessary to accelerate the stage from stationary to the optimum velocity V o at the start of a row and decelerate the stage from the optimum velocity V o to stationary at the end of the row. It is important that the acceleration/deceleration of the stage at the beginning and end of a row should be such that the movement of the stage is smooth throughout image acquisition to achieve consistently clear images.
Accordingly, in the preferred embodiment as illustrated in FIG. 3A , the stage is moved under control of computer 19 to steadily increase the velocity of the stage up to the optimum velocity V o in the minimum time. The acceleration applied to the stage is determined and controlled by computer 19 and is dependent upon properties of the motorised stage 5 , and the determined optimum velocity V o . Typically, the time taken to ramp up to the optimum velocity represents only about 5% of the time for the imaging of the row, and similarly the time taken to ramp down from the optimum velocity represents only about 5% of the time for the imaging of the row.
Whilst in the preferred embodiment, images are acquired during the acceleration and deceleration stages respectively at the beginning and end of a row, in an alternative implementation, it would be possible to accelerate the stage to the optimum velocity before reaching the starting position and similarly decelerate the stage after the end of a row. This would require careful synchronisation of camera and stage to ensure that the operation of the camera is synchronised with the beginning and end of a row. In addition, the imaging time would be increased due to the extra distance travelled beyond the specimen area during the acceleration and deceleration of the stage for each row.
In the preferred embodiment it is desirable to monitor and control the velocity of the microscope stage in conjunction with the shutter speed of the camera 25 in order to assist in the subsequent image processing.
Furthermore, in order to reduce the imaging time to a minimum, it is desirable to acquire images with a minimum overlap (so that fewer images are acquired for each row) but having sufficient duplication in data to enable accurate cross-correlation to be performed. This is achieved by using the shortest possible exposure time (i.e. fastest possible shutter speed) for the camera 25 (typically the exposure time is of the order of μs), to avoid motion blurring (a well known phenomenon associated with photographing a moving object), and the fastest possible frame rate (number of frames per second) for the camera 25 (typically 9 to 15 frames per second), whilst moving the microscope stage at an optimum speed of to achieve a desired overlap, typically about 10% using current cross-correlation techniques.
Thus, the optimum velocity V o for the stage 5 is calculated such that i) the distance travelled by the stage in the time period that the shutter is open (shutter speed) is sufficiently small to avoid blurring of the image due to motion blur, whilst at the same time ii) the distance travelled by the stage in the time interval between the operation of the shutter (time interval=1/frame rate) must be sufficiently large that the next image includes a maximum amount of new image data (i.e. a minimum overlap or duplication of image data that is sufficient for accurate cross-correlation).
FIG. 3B illustrates the specimen area 8 of the microscope slide 7 from which the images are acquired. The starting and finishing positions at the beginning and end of a row are illustrated by a solid line, and the boundaries of the images acquired are illustrated by a dashed line.
Although not essential to the invention, in the preferred embodiment, the time interval between operation of the camera shutter is substantially constant. Thus, the images at the beginning and end of a row may overlap by a greater distance than the images in the middle of the scan. For the various positions in the row, the amount of overlap of the acquired images can be determined using the velocity information and the shutter interval, which can then be used during the reconstruction or mosaicing of the images to form the composite image of the entire specimen as described below.
FIG. 4 illustrates the areas of the acquired images, at the beginning, middle and end of a row, which are used during the cross-correlation processing to properly align the separate acquired images to form the composite image. As shown in FIG. 4 , since the approximate amount of overlap at these positions can be predicted based on the velocity of the stage, only a portion of each image, centred around the expected position of overlap, needs to be used in the cross correlation processing to create the optimum alignment of the images with each other. Thus, the cross-correlation technique compares the pixels of a vertical line in the area used for alignment of one image with the pixels of vertical lines in the region of overlap in the adjacent image. When a match or substantial match is achieved with respect to one or several adjacent lines of pixels, alignment is considered to be achieved.
As will be appreciated from the above description, the processing of the image data to align the acquired images can be performed simultaneously with or subsequent to the acquisition of the image data.
In an example, the inventors performed imaging of a specimen area of about 20 mm×20 mm using a 20× Apochromat objective lens in a Zeiss Axioplan 2 Imaging microscope having a Prior Scientific proscan motorised stage. A Hamamatsu Orca C4742SC camera was used to capture images with the exposure time set to “2” (believed to be 2 ms) and the frame rate was 9 frames s −1 .
The imaging process produced 4225 (65×65) individual images and was completed in a time of about 15 minutes. The overlap between adjacent images in a row was found to be in the region of 10% of the image area or about 100 pixels and between adjacent rows of less than 0.05% or about 5 pixels. The image data processing time for the complete specimen area was about 10 minutes. Good image alignment was achieved using currently available cross-correlation techniques and the composite overall image of 65000 by 65000 pixels representing the 20 mm by 20 mm specimen area provided good image resolution when reproduced on screen.
Thus, by continuous movement of the stage during the image acquisition process, it is possible to reduce the scanning time for a complete specimen at medium (e.g. 20×) and high (e.g. 40×) magnifications, to less than an hour for a standard specimen area of 20 mm×20 mm. Thus, the images are available more quickly for diagnosis by a pathologist.
Moreover, although the image processing time is increased in comparison to prior art techniques in which contiguous images are acquired, since the processing can be performed remote from the imaging system, the imaging system itself is made available more quickly for imaging further specimens. Moreover, through the use of multi-threading techniques and more powerful processors, theoretically, the processing time could be reduced below 10 minutes.
Various modifications and changes can be made to the described embodiments.
For example, it would be possible to acquire the images using a strobe light to periodically illuminate the specimen. By synchronising the illumination by the strobe with the shutter of the camera a slower shutter speed can be used.
Moreover, although in the described embodiment a constant frame rate (shutter interval) is used, the frame rate may be adjusted with changes in velocity of the stage to optimise the imaging process.
If the preferred embodiment, each row of images is captured starting at a first end of the specimen area, whereby the stage is driven in a zig-zag path so that the images are output in raster-scan order. It will be appreciated that in other embodiments, alternate rows of images may be captured starting at the second end of the specimen area, so that the imaging portions of the path are not interlinked by long-diagonal non-imaging return paths. In this case, the images would not be output in raster-scan order and the image data would therefore be processed differently.
Whilst the preferred embodiment uses a digital CCD camera, in an alternative embodiment an analog video camera may be used to capture the images.
It is intended to include all such variations, modifications and equivalents which fall within the spirit and scope of the present invention as defined in the accompanying claims.
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A method and apparatus for acquiring digital microscope images is disclosed, in which a plurality of magnified images of a specimen are captured for tiling together to provide an overall composite image of the specimen. In accordance with the described method, the specimen is moved relative to an imaging system comprising a microscope and camera in a predetermined path whilst the plurality of magnified images are captured. In a preferred embodiment, the specimen, contained on a slide, is mounted on a movable microscope stage, and is moved beneath the microscope in the predetermined path. The velocity of the movement of the stage and the shutter speed of the camera is computer controlled to capture overlapping, clear images.
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RELATED APPLICATION
The present application is a Continuation-in-Part of pending application Ser. No. 351,289, filed Feb. 22, 1982, now abandoned.
BACKGROUND OF THE INVENTION
This invention concerns Si-Al-O-N type materials and is more particularly concerned with the double phase Si-Al-O-N useful for the manufacture of cutting inserts used in metalworking.
There are numerous papers and patents describing the relatively new Si-Al-O-N materials which have been created by the addition of the aluminum and oxygen atoms to silicon nitride materials.
Most recently, these materials have found their way into the metalworking industry and have provided possibilities in the working of cast iron, nickel, based super alloys, and other similar substances.
More particularly, cutting inserts of a Si-Al-O-N type material made in accordance with U.S. Pat. No. 4,127,416, which is incorporated herein by reference, have proven to be useful in certain metal-working situations. The type of material made by the above-mentioned United States patent is manufactured as a predominantly single phase β-Si-Al-O-N material with approximately 10 to 20 percent of a glassy phase present.
The material is made essentially as described in the patent which involves forming a polytype material as an initial step in the process. The polytype material may then be reacted with a controlled amount of silicon nitride and an oxide of yttrium, lithium or calcium to form a ceramic of at least 80, and preferably 95, percent being of a single phase β-type Si-Al-O-N.
Such a material, when produced, has a transverse rupture strength in the range of 100,000 to 110,000 pounds per square inch using the procdure described in later examples and a knoop hardness in the range of 1450 to 1800 kilograms per square millimeter at 100 grams load.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, a double phase Si-Al-O-N material is produced, especially for use as a cutting insert material. The double phases are comprised of α and β phase Si-Al-O-Ns.
It was discovered that control of the amount of alumina in the mixture together with a neutral media for milling allows one to control the composition of the final material such that the α and β type Si-Al-O-N phases will appear. Less alumina produces a greater amount of α phase Si-Al-O-N. Control of the other starting components will also produce the same effect, such as less silica, more aluminum nitride, more polytype, increased yttria all produce more α Si-Al-O-N in the finished product. Preferably, the α phase Si-Al-O-N will range from 10 to 70 percent by weight, while the β phase Si-Al-O-N in the composition will range from 20 to 90 percent by weight. A glassy phase ranging from zero to 10 percent by weight will also be present.
Increasing the α-Si-Al-O-N in the composition causes the hardness to be increased without significantly affecting the transverse rupture strength of the material.
Compounds of yttrium are used as sintering aids in the manufacture of the above-mentioned product, but it is to be recognized that similar results could be obtained with oxides of scandium, cerium, lanthanum and the elements of the lanthanide series.
Use of the yttria as the preferred sintering aid gives rise to an intergranular component predominantly comprising a glassy phase but which may also comprise other phases which include YAG (yttrium aluminum garnet) which is a cubic phase having the formula Y 3 Al 5 O 12 ; Y-N-α-Wollastonite, which is a monoclinic phase of formula YSiO 2 N; YAM, which is a monoclinic phase of the formula Y 4 Al 2 O 9 ; N-YAM, which is a monoclinic phase of formula Y 4 Si 2 O 7 N 2 which is isostructural with YAM and forms a complete solid solution with it.
BRIEF DESCRIPTION OF THE DRAWINGS
The exact nature of the invention will become more clearly apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:
FIG. 1 shows the silicon nitride corner of the base plane of the Si-Al-O-N phase diagram as defined in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention concerns a dual phase Si-Al-O-N ceramic and glassy phase product and method of making said product which comprises the steps of forming a powder mixture consisting essentially of a first component consisting of compounds containing the elements silicon, aluminum, oxygen and nitrogen in proportions such that the ratio of the total number of silicon and aluminum atoms to the total number of oxygen and nitrogen atoms lies in the range 0.735 to 0.77 and such that said compounds react, together with the second component, during the subsequent sintering process to produce a double phase ceramic material with a first phase obeying the general formula Si 6-z Al z O z N 6-z where z is between 0.38 and 1.5, and a second phase being an hexagonal phase and obeying the general formula (Si, Al) 12 M x (O, N) 16 where M can be calcium, or yttrium, or any of the lanthanides, and x is between 0.1 and 2. The second component comprises between 0.1 and 10 percent based on the total weight of the first and second components, the second component being an oxide of at least one of the further elements yttrium, scandium, cerium, lanthanum, and the metals of the lanthanide series. Said mixture is then sintered in a protective (protective meaning non-reactive) environment with or without the application of pressure at a temperature between 1600 degrees Centigrade and 2000 degrees Centigrade and for a time, decreasing with increasing temperature, of at least ten minutes to at least five hours so as to produce a ceramic material containing at least 90 percent by volume of said double phase ceramic material with said second phase containing part of said second component.
In the method described in the preceding paragraph, the compounds of the first component are arranged so that the sum of all the silicon and aluminum atoms in the compounds divided by the sum of all the oxygen and nitrogen atoms present is between 0.735 and 0.77, or more preferably 0.745 to 0.76. The two component mixture is then sintered in a protective (protective meaning non-reactive) environment, preferably a non-oxidizing environment, or more preferably, a reducing environment, at 1600 degrees Centigrade to 2000 degrees Centigrade for a time sufficient to produce at least 90 percent by volume of the silicon aluminum oxynitride ceramic material defined by the above formulae. The sintering time required increases with decreasing temperature so that, although the minimum time is only ten minutes in the case of a 2000 degrees Centigrade sintering temperature, with a temperature of 1600 degrees Centigrade, a sintering time of at least five hours is required.
The components forming the first component of the original mixture are conveniently silicon nitride, aluminum nitride, alumina and silica, with at least part of the silica and alumina being present as inherent impurities on the silicon nitride and aluminum nitride, respectively.
Alternatively, the first component may be defined by silicon nitride and a ceramic intermediary containing a silicon aluminum oxynitride which does not obey the general formula Si 6-z Al z O z N 6-z . Such materials are referred to as polytypes and are described and defined in U.S. Pat. No. 4,127,416, which has already been incorporated herein by reference. Examples 7 through 17 utilize the 21R type polytype defined in said United States patent. Preferably, the silicon aluminum oxynitride of the ceramic intermediary has a rhombohedral structure and obeys the approximate formula SiAl 6 O 2 N 6 . Moreover, the ceramic intermediary is preferably formed by heating a powder mixture of alumina, aluminum and silicon to between 1200 degrees Centigrade and 1400 degrees Centigrade in a nitriding atmosphere, the heating rate being controlled to substantially prevent exotherming, and then sintering the nitrided mixture at a temperature between 1500 degrees Centigrade and 1900 degrees Centigrade.
Alternatively, the intermediary may be formed by heating a powder mixture of alumina, aluminum nitride and silicon nitride at a temperature between 1200 degrees Centigrade and 2000 degrees Centigrade in a protective environment, preferably a nonoxidizing environment, or more preferably, a reducing environment.
In the methods described above, the relative proportions of the compounds present in the mixture are arranged so as to produce the dual phase ceramic material with a first phase obeying the formula Si 6-z Al z O z N 6-z and a second phase obeying the formula (Si, Al) 12 M x (O, N) 16 where z is between 0.38 and 1.5 since having the z value within these limits is found to produce a coherent product having a high strength even when the sintering is performed in the absence of pressure. If, on the other hand, the z value is allowed to fall below 0.38, the material becomes difficult to sinter without the application of pressure, while the strength of the product deteriorates if the z value is allowed to increase above 1.5.
Moreover, the relative proportions of the compounds in the first component are arranged so as to provide the above defined atomic ratio of between 0.735 and 0.77 since, if the ratio falls below 0.735, it is found that the mixture becomes too oxygen-rich. This results in the production of an excessive amount of glass during sintering which not only has a deleterious effect on the high temperature strength properties of the product, but is also found to adversely affect the low temperature strength properties. Moreover, it is found that the glass cannot be removed by the subsequent heat treatment process discussed in detail below. By way of contrast, if said atomic ratio exceeds 0.77, it is found that there is insufficient oxygen present to form the glass required to effect consolidation of the product.
The permitted range of 0.1 to 10 percent by weight for the second component of the starting mixture is also chosen on the basis that it provides a satisfactory glass content in the sintered product. The elements selected for the second component are cerium, yttrium, scandium, lanthanum or one of the lanthanide series since these have highly refractory oxides which produce high melting point glasses with the silica and alumina present and hence allow the product to be used at higher temperature than would be possible with low melting point glasses. The second component is also necessary for the formation of the α-Si-Al-O-N phase of the first component since, by definition, the α-Si-Al-O-N contains yttrium or one of the lanthanides. Of the elements selected for the second component, yttrium is preferred, since the presence of yttria in the sintering mixture is found to result in products of high strength even without the application of pressure.
It will be seen that performing the methods described above results in the formation of a sintered ceramic product containing at least 90 percent by volume of a dual phase silicon aluminum oxynitride, together with an intergranular component predominantly comprising a glassy phase but also possibly containing other phases such as YAG, YAM, N-YAM and Y-N-α-Wollastonite. The presence of glass aids consolidation of the product during sintering, but tends to result in a lowering of the high temperature properties of the final component. It has, however, been found that the amount of the glass phase in the sintered product can be reduced by subjecting the product to a final heat treatment process which involves raising the temperature of the product to within 200 degrees Centigrade of the melting point of the glass (i.e., to about 1400 degrees Centigrade in the case of an yttrium glass), and then cooling the product to crystallize at least part of the glass into an intergranular component containing other phases such as YAG, YAM, N-YAM and Y-N-α-Wollastonite.
EXAMPLES
Starting materials used in this application are as listed below, but can be the same starting materials listed in the aforementioned Lucas U.S. Pat. No. 4,127,416, or any of the other known starting materials meeting the known conditions for the manufacture of Si-Al-O-N materials.
______________________________________Silicon (Elkem Metals) Fe <1.0% C 0.1-0.4% typical Ca <.07% typical Al <.53% -200 mesh particle sizeYttrium (Molycorp, a division of 99.99% pureUnion 76) -325 mesh particle sizeAluminum (Alcan Aluminum 99.3% pureCorporation 16 micron average particle sizeAlumina (Reynolds) RC-172DBM 99.7% Al.sub.2 O.sub.3 .04% Na.sub.2 O .07% SiO.sub.2 .03% Fe.sub.2 O.sub.3 particle size <1 micronAlumina (Alcoa) A-16SG 99.5% Al.sub.2 O.sub.3 .05-.09% Na.sub.2 O .02-.04% SiO.sub.2 .01-.02% Fe.sub.2 O.sub.3 particle size <1 micron______________________________________
In Table 2, the percent α-Si-Al-O-N and β-Si-Al-O-N was originally based on 100 percent, since no other crystalline phases were present and ignored the 10 percent glass which cannot be quantified by x-ray diffraction. The percentages were revised to include the 10 percent glass and, therefore, the percentages α-Si-Al-O-N and β-Si-Al-O-N will total 90 percent, making the percentages consistent with Table 2 (continued). Depending upon the convention one chooses, the percentages will be correct.
EXAMPLE 1
A composition consisting of 92 parts by weight silicon nitride powder (containing about 4 weight percent surface silica), 5 parts by weight of aluminum nitride (containing about 6 weight percent surface alumina), 5 parts by weight of alumina and 7 parts by weight of yttrium oxide was milled in isopropanol for 96 hours using Si-Al-O-N media to a mean particle size of 0.96 microns. Following drying, the powder was screened through a 50 mesh sieve and isostatically pressed at 30,000 psi. Pieces of green material were cut from the isostatically pressed slug and buried in a 50/50 by weight boron nitride and silicon nitride powder mixture inside a graphite pot. The pot was placed in a graphite element resistance-heated furnace and raised to 500 degrees Centigrade in vacuum and then to 1830 degrees Centigrade in one atmosphere pressure of nitrogen at which temperature it was held for 40 minutes. After cooling bars of the sintered material 0.2×0.2×0.8 inches were ground using a 600 grit abrasive wheel and, following die checking, they were broken in 3 point bend with an outer span of 0.56 inches. Broken pieces were used for density and hardness measurements and phase determination by x-raouter span of 0.56 inches. Broken pieces were used for density and hardness measurements and phase determination by x-ray diffraction. Properties of the material are given in Table 1.
EXAMPLE 2
As Example 1, but sintered at 1830 degrees Centigrade for 60 minutes
EXAMPLE 3
A composition consisting of 92 parts by weight silicon nitride powder (containing about 4 weight percent surface silica) 5 parts by weight of aluminum nitride (containing about 6 weight percent surface alumina) 3 parts by weight of alumina and 7 parts by weight of yttrium oxide was milled in isopropanol using alumina grinding media for 48 hours. Attrition from such media amounted to 1.9 parts by weight, which incorporated into the overall composition. The mean particle size of the milled powder was 1.49 microns. The powder was processed as in Example 1, except that sintering was carried out at 1780 degrees Centigrade for 40 minutes and 1830 degrees Centigrade for 15 minutes. Properties are given in Table 1.
EXAMPLE 4
A composition consisting of 92 parts by weight silicon nitride powder (containing about 4 weight percent surface silica), 8 parts by weight of aluminum nitride (containing about 6 weight percent surface alumina), and 7 parts by weight of yttrium oxide was milled in isopropanol for 168 hours using dense Si-Al-O-N media to a mean particle size of 0.63 microns. Then as in Example 1.
EXAMPLE 5
Material, as in Example 4, was given a heat-treatment of 1400 degrees Centigrade for five hours in a static nitrogen atmosphere. Results in Table 1.
EXAMPLE 6
A composition consisting of 92 parts by weight of silicon nitride powder (containing about 4 weight percent surface silica), 8 parts by weight of aluminum nitride (containing about 6 weight percent surface alumina), and 5 parts by weight of yttrium oxide was milled in isopropanol using alumina grinding media for 48 hours. Attrition from such media amounted to 2.0 parts by weight which was incorporated into the overall composition. The mean particle size of the milled powder was 1.47 microns. Then as in Example 1, but sintered at 1850 degrees Centigrade for 60 minutes. Results in Table 1.
POLYTYPE EXAMPLES
EXAMPLE 7
A powder mixture was made up comprising 86.9 W/O (weight percent) silicon nitride, 6.59 w/o 21R polytype and 6.54 w/o yttria. The powder mixture was then milled for two days utilizing Si-Al-O-N cycloids as the media until the resulting average particle diameter was 1.07 microns and 90 percent finer than 2.21 microns. The powder was then cold isostatically pressed at 30,000 psi, and the green slug was then sintered under the same conditions as the previous examples at 1830 degrees Centigrade for 50 minutes.
The sintered material was then analyzed and properties are given in Table 2.
EXAMPLE 8
The powder was processed as described in Example 7 except that the starting powder mixture consisted of 81.3 w/o silicon nitride, 12.1 w/o 21R polytype, 6.54 w/o yttria. Sintered material was analyzed and properties are given in Table 2.
EXAMPLE 9
The processing of this powder was the same as in Examples 7 and 8, except that the ball milling media was alumina cycloids. The original powder mixture was 86.9 w/o silicon nitride, 6.54 w/o 21R polytype, and 6.54 w/o yttria. The powder was milled at an average particle diameter of 0.91 microns and 90 percent finer than 1.72 microns. It was found that the powder mixture had an additional 3.55 w/o milled pick-up from the alumina cycloids.
The mix was then sintered at 1780 degrees Centigrade for forty minutes and 1830 degrees Centigrade for 25 minutes. The sintered material was analyzed and properties are given in Table 2.
EXAMPLE 10
The powder mixture was processed with 82.2 w/o silicon nitride, 11.2 w/o 21R polytype, 6.54 w/o yttria and an additional 3.57 w/o from wear of alumina cycloids during ball milling. The average particle diameter was 0.93 microns with 90 percent finer than 1.77 microns after milling. This composition was sintered on the same schedule as Example 9. The sintered material was then analyzed and properties are given in Table 2.
EXAMPLE 11
The powder mixture was processed with 85 w/o silicon nitride, 8.4 w/o 21R polytype, 6.54 w/o yttria, and a direct addition of 2.51 w/o alumina and 0.1 w/o of silica. The mix was milled with Si-Al-O-N media to an average diameter of 1.0 microns. The sintered material was then analyzed and properties are given in Table 2.
EXAMPLE 12
A composition consisting of 83 parts by weight Si 3 N 4 (with 1.0 w/o O as a surface layer), 17 parts by weight 21R polytype, 7 parts by weight yttria and 3 parts by weight alumina was milled in isopropanol for 72 hours using Si-Al-O-N media to a mean particle size of 0.71 microns. Following drying, the powder was screened through a 50 mesh sieve and isostatically pressed at 30,000 psi. Pieces of green material were cut from the isostatically pressed slug and buried in a 75/25 by weight silicon nitride and boron nitride powder mixture inside a graphite pot. The pot was placed in a graphite element resistance heated furnace and raised to 900 degrees Centigrade under vacuum and then to 1780 degrees Centigrade for 40 minutes in one atmosphere nitrogen followed by 25 minutes at 1830 degrees Centigrade and cooled in approximately 30 minutes to 1000 degrees Centigrade. Properties are given in Table 2.
EXAMPLE 13
A composition consisting of 77 parts by weight silicon nitride (with 1.09 w/o O as a surface layer) 23 parts by weight 21R polytype, 7 parts by weight yttria and 3 parts by weight alumina. Processing was identical to Example 12. The mean particle size of the milled powder was 0.84 microns. Properties are given in Table 2.
EXAMPLE 14
A composition consisting of 75 parts by weight silicon nitride (with 1.09 w/o O as a surface layer), 25 parts by weight 21R polytype, 7 parts by weight yttria and 3 parts by weight alumina. Processing was identical to Example 12. The mean particle size of the milled powder was 0.92 microns. Properties are given in Table 2.
EXAMPLE 15
A composition consisting of 75 parts by weight silicon nitride (with 0.77 w/o O as a surface layer), 25 parts by weight 21R polytype, 7 parts by weight yttria and 9 parts by weight aluminum oxide. Processing was identical to Example 12. The mean particle size of the milled power was 0.82 microns. Properties are given in Table 2.
EXAMPLE 16
A composition consisting of 85 parts by weight silicon nitride, 15 parts by weight 21R polytype, 7 parts by weight yttria and 1.0 parts by weight alumina. Processing was identical to Example 12. The mean particle size of the milled powder was 0.95 microns. Properties are given in Table 2.
EXAMPLE 17
A composition consisting of 85 parts by weight silicon nitride, 15 parts by weight polytype, 7 parts by weight yttria and 8 parts by weight alumina. Processing was identical to Example 12. The mean particle size of the milled powder was 1.09 microns. Properties are given in Table 2.
The composite material produced in the above examples showed superior metalcutting results when used as a cutting insert. Superior results were obtained when machining cast iron and nickel base alloys. Test results reported in the tables for the first eleven examples reported the transverse rupture strength of the material as determined by the method described in the Lucas Industries U.S. Pat. No. 4,127,416 and the dimensions specified in Example 1 of the specification.
Subsequently, it was decided that fracture toughness of the material was a much better indication of metal-cutting ability for the material than the transverse rupture values. For new Examples 12 through 17, these values are now reported instead of the transverse rupture values.
The fracture toughness tests used a Vickers diamond indentation with an 18 kilogram load. Fracture toughness was calculated from the dimensions of the indentation and associated cracks together with the load and a Youngs modulus value of 305 G Pa using the method described in A. G. Evans and E. A. Charles Journal of the American Ceramic Society, Volume 59 (1976), Page 371.
Examples 10, 12, 13 and 14 demonstrate the increase in percent α-Si-Al-O-N with increasing polytype. Examples 16 and 17, 14 and 15 demonstrate the decrease in α-Si-Al-O-N content and hardness with alumina content.
The present invention is further defined with reference to FIG. 1. Reference is had to Lucas Industries U.S. Pat. Nos. 4,127,416 and 4,113,503, in which the Si-Al-O-N phase diagram is shown.
The rectangular composition area claimed by Lucas is outlined in the attached drawing. The boundaries are set at z values of 0.38 and 1.5, where "z" is found in the formula for β-Si-Al-O-N of Si 6-z Al z O z N 8-z . The upper and lower boundaries are cation to anion ratios (c/a) of 0.735 and 0.770. Lucas defined the c/a ratio as moles silicon plus moles aluminum divided by the quantity moles oxygen plus moles nitrogen. The contribution of yttria was not included. Exceeding the upper c/a ratio, results in too much glass, which is deleterious to properties of the single phase β-Si-Al-O-N. Sintering the single phase β-Si-Al-O-N is difficult with ratios higher than 0.770.
The compositional area, which overlaps the Lucas area, was defined with distinct differences. The boundaries set at z=0.38 and z=1.5 are common with Lucas, but the upper and lower boundaries are based on the presence of a two-phase ceramic, α-Si-Al-O-N plus β-Si-Al-O-N. The c/a ratio is defined as moles silicon plus moles aluminum plus moles yttrium divided by the quantity moles oxygen plus moles nitrogen. Yttria is included in the c/a ratio, which is appropriate since yttrium is an integral part of α-Si-Al-O-N.
Second, the equivalents calculated by Lucas considers only Si, Al, O, N, excluding Y 2 O 3 . The present compositions have equivalent calculated with yttria, which result in a compositional point slightly above the base plane on the phase diagram. The compositional point is then projected onto the base plane resulting in an effective equivalent for silicon and aluminum. Oxygen and nitrogen will not be affected. The effective equivalents are plotted in FIG. 1. The table below shows the differences between Lucas and the present method for Example 9.
TABLE I______________________________________ Si Al O N Y c/a______________________________________Lucas .9299 .0701 .0553 .9447 -- .747EquivalentEquivalent .9102 .0687 .0753 .9247 .0211 .744(includingY.sub.2 O.sub.3)Effective .9208 .0793 .0753 .9247 -- --Equivalent______________________________________
In this manner, the compositional region is defined on the base plane, but is indirectly accounting for the influence of yttria, which is important since yttria enters the α-Si-Al-O-N structure.
The upper boundary segment with a constant c/a ratio of 0.739 represents the effective equivalent compositions of a final composition between 0-10% α-Si-Al-O-N. Examples 17 and 15 define a line O eff eq =0.1644(Al eff eq)+0.0865, which intersects the line of constant c/a of 0.739 at (0.1143, 0.1053) and the line of z=1.5 at (0.2084, 0.1208). The combination of the c/a ratio 0.739 line segment with the segment between the points of intersection described above represents the compositions with an effective equivalent percent that result in a final α-Si-Al-O-N content of 0-10%. The lower boundary represents a constant c/a ratio of 0.794. The ratio corresponds to the compositional range for α-Si-Al-O-N with the maximum practical yttrium substitution in the α-Si-Al-O-N structure. The general α-Si-Al-O-N formula, proposed by K. H. Jack, in "The Role of Additives in the Densification of Nitrogen Ceramics," (Oct. 1979), for European Research Office, United States Army Grant No. DAERO-78-G-012, is Y x Si 12- (m+n)Al m=n O n N 16-n where x= O-2 , m=1-4 and n=0-2.5.
DEFINITION OF PHASES
1. β' is an hexagonal phase having the general formula Si 6-z Al z O z N 8-z where O<z≦4.2 Detected by X-ray diffraction-characteristic patterns for z=O and z=4β'.
2. α' is an hexagonal phase having the general formula (Si, Al) 12 M x (O, N) 16 where M=Li, Ca, Y or other lanthanides. Theoretical maximum is x=2; this is approached in the case of Ca but, for Y, practical maximum is about 0.7. Detected by X-ray diffraction.
3. α-Si 3 N 4 is an unsubstituted allotrope of Si 3 N 4 .
4. N-YAM is an monoclinic phase of formula Y 4 Si 2 O 7 N 2 . Isostructural with YAM-Y 4 Al 2 O 9 and forms a complete solid solution with it.
5. Y-N-α-Wollastonite is a monoclinic phase of formula YSiO 2 N.
6. YAG is a cubic phase of formula Y 3 Al 5 O 12 . Some substitution of Al by Si and simultaneous replacement of O by N may occur.
TABLE 1__________________________________________________________________________TransverseRupture Rockwell "A" Knoop HardnessStrength Hardness (at (100 g load) Density Phases PresentExample(psi) 60 kg load) (kg mm.sup.-2) (g cm.sup.-3) % β' % α-Si.sub.3 N.sub.4 /α' 1 Other__________________________________________________________________________1 106,000 93.2 1940 3.266 81 9 Y-containing glassy phase, trace N--YAM (Y.sub.4 Si.sub.2 O.sub.7 N.sub.2)2 115,000 93.4 1890 3.271 84 6 Y-containing glassy phase, trace N--YAM (Y.sub.4 Si.sub.2 O.sub.7 N.sub.2)3 87,000 92.5 1730 3.203 80 10 Y-containing glassy phase, N--YAM (Y.sub.4 Si.sub.2 O.sub.7 N.sub.2) and Y--N--α-Wollastonite (YSiO.sub.2 N)4 100,000 94.6 2150 3.275 47 43 Y-containing glassy phase, N--YAM (Y.sub.4 Si.sub.2 O.sub.7 N.sub.2) and Y--N--α-Wollastonite (YSiO.sub.2 N)5 96,000 94.8 2310 3.280 49 41 N--YAM, Y--N--α-Wollasto nite, trace - YAG (Y.sub.3 Al.sub.5 O.sub.12)6 -- 93.0 1980 3.175 58 32 Y-containing glassy phase, N--YAM__________________________________________________________________________
TABLE 2__________________________________________________________________________TransverseRupture Rockwell "A" Knoop HardnessStrength Hardness (at (100 g load) Density Phases PresentExample(psi) 60 kg load) (kg mm.sup.-2) (g cm.sup.-3) % β' % α-Si.sub.3 N.sub.4 /α' Other__________________________________________________________________________ 7 83,485 92.9 -- 3.25 74.7 15.3 Y-containing glassy phase with no intergranular crystalline phases 8 106,785 94.7 1761 3.276 34.2 55.7 Y-containing glassy phase with no intergranular crystalline phases 9 111,990 92.9 1718 3.27 76.0 14.0 Y-containing glassy phase with no intergranular crystalline phases10 94,856 94.0 -- 3.26 54.0 36.0 Y-containing glassy phase with no intergranular crystalline phases11 111,596 93.3 1765 3.25 63.9 26.1 Y-containing glassy phase with no intergranular crystalline phases__________________________________________________________________________ Rockwell "A" Knoop HardnessFracture Hardness (at (100 g load) Density Phases PresentExampleToughness 60 kg load) (kg mm.sup.-2) (g cm.sup.-3) % β' % α-Si.sub.3 N.sub.4 /α' Other__________________________________________________________________________12 7.59 94.0 1632 3.28 51.3 38.7 No other phases present13 7.23 93.9 1611 3.30 44.3 45.7 No other phases present14 7.32 94.2 1598 3.30 44.5 45.5 No other phases present15 7.44 93.0 1546 3.30 80.4 9.6 No other phases present16 6.90 94.5 1680 3.27 31.5 58.5 No other phases present17 5.72 92.9 1503 3.26 90 -- No other phases__________________________________________________________________________ present
Modifications may be made within the scope of the appended claims.
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A dual phase silicon aluminum oxynitride material comprising a first phase Si-Al-O-N, commonly referred to as β-Si-Al-O-N, and a second phase Si-Al-O-N referred to as α-Si-Al-O-N. In addition to the double phase Si-Al-O-Ns, there is included a glassy type material which can formulate up to ten percent by weight of the total composition. The material may be manufactured by forming a polytype material made from reacted alumina, aluminum nitride and silicon nitride. The polytype material may be mixed with further powders of silicon nitride and an oxide of yttrium, lithium or calcium and finally reacted to a double phase Si-Al-O-N material where hardness is increased as the additional α-Si-Al-O-N is increased without significantly affecting its strength.
The material may be formed in situ by mixing aluminum nitride, alumina, silicon nitride, together with an oxide of yttrium, lithium or calcium. These materials can then be sintered to a final product containing a double phase Si-Al-O-N. Control of the alumina content in the polytype or in situ methods affects the percentage of α-Si-Al-O-N produced in the final product. The hardness of the material increases with the α-Si-Al-O-N content without significantly affecting its transverse rupture strength.
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The present application is a continuation of and claims priority to U.S. application Ser. No. 10/389,002, filed Mar. 14, 2003; now U.S. Pat. No. 7,335,344 the entire contents of the above-referenced application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to method and apparatus for synthesizing filamentary structures including nanotubes in the post-flame region of a non-sooting premixed or non-premixed flame using unsupported catalysts.
Since their discovery in 1991 (1), carbon nanotubes have sparked a surge of interest (2-5). Numbers in parentheses refer to the reference list included herein. The teachings in all of these references are incorporated by reference herein. The many unique properties of nanotubes gives appeal to a wide range of potential applications in areas such as mechanical actuators (6, 7), sensors (8-10), polymer composites (11), electronics (12-16), biosensors and biocompatibility (17, 18), gas storage (19-22), adsorption (23-25), and catalysis (26-28). Techniques that have been demonstrated to synthesize carbon nanotubes include laser ablation (29, 30), plasma arc (31), chemical vapor deposition (CVD) (32-34), fluidized bed reactors (35, 36), and combustion systems (37-51).
Flames offer potential as means of producing bulk quantities of carbon nanotubes in a continuous, economically favorable process. There are three key requirements for nanotube synthesis common to most of the synthesis techniques: 1) a source of carbon, 2) a source of heat, and 3) presence of metallic catalyst particles. A fuel-rich flame is a high-temperature, carbon-rich environment that can be suitable for nanotube formation if certain metals are introduced into the system.
There have been a number of reported observations in the combustion literature of nanotubes and filamental carbon structures within flame systems. Perhaps the earliest observation of intriguing tube-like structures in flames is reported by Singer (52) in the 1950s and within the last decade there have been occasional reports of nanotube structures (38, 49, 50, 53-57). These observations are typically reported as curiosities and are largely serendipitous in nature. In recent years Diener et al. (51), Saito et al. (49, 50), and Vander Wal et al (37-45) have independently made more detailed studies of nanotube formation in flames.
Diener et al. (51) report the synthesis of single-walled carbon nanotubes in sooting flames. A semi-premixed flame configuration is used with fuel gases (acetylene, ethylene or benzene) issued through numerous small diameter tubes distributed through a sintered metal plate through which oxygen flows, drafting past the fuel tubes. Iron and nickel bis(cyclopentadiene) compounds are vaporized and issued to the flame feed as a metal catalyst precursor. Single-walled carbon nanotubes are observed in acetylene and ethylene flames (within the equivalence ratio range of 1.7 to 3.8) while multi-walled nanotubes are observed in benzene flames (within the equivalence ratio range of 1.7 to 3.4). An equivalence ratio, φ, is defined as the actual fuel/oxygen ratio divided by the stoichiometric fuel/oxygen ratio corresponding to conversion of all carbon to CO 2 and all hydrogen to H 2 O. Diener et al. do not report the level of dilution with argon, the concentration of metal species added to the flame, or the inlet velocity for the feed gas mixture—all are parameters affecting nanotube formation in flames. The reported overall single-walled carbon nanotube yields are very low “certainly less than 1% of the carbon soot product” and this small population of single-walled walled carbon nanotubes is confirmed by inspection of the transmission electron microscope (TEM) micrographs in the article. The nanotube bearing soot material analyzed by Diener et al. is collected from a filter system far downstream from the burner and there is no information relating to the time, temperature or concentration history of the material, making it difficult to judge the extent to which nanotubes were in fact formed in the flame and how much growth occurred during extended exposure to flame exhaust while collecting in associated downstream systems. Prior to analysis, the material is prepared using a separation technique employing sonication of the soot in methanol to disperse the sample—it is unclear how this preparation technique might alter the composition of the material and if the material is representative of solid material present in the flame itself. Diener et al. place emphasis on the use of sooting flames for the synthesis of their materials which is in fact analogous to the approach reported by Howard et al. (46-48), Richter et al. (55), and Duan et al. (54). The reported range of equivalence ratios is stated as 1.7 to 3.8 which is very much focused on exploiting sooting conditions. Furthermore, the quantities of nanotubes observed in the condensed material is very small (<1%).
Saito et al. (49, 50) immersed metallic substrates in various hydrocarbon fueled diffusion flames and observed multi-walled carbon nanotubes that had formed on the substrate. It will be understood by those familiar with the combustion literature that a diffusion flame is one type of non-premixed flame. Vander Wal and coauthors have observed single walled nanotubes in a hydrocarbon (acetylene or ethylene)/air diffusion flame with nitrogen diluent and metallocene catalyst precursor compound added to the fuel stream (38).
Vander Wal and coworkers make extensive use of an annular burner configuration consisting of a 50 mm diameter sintered metal plate with a central tube of 11 mm diameter that is mounted flush with the surface of the burner plate. See FIG. 1 . For most experiments Vander Wal et al. established a fuel rich premixed flame supported on the outer annular section of a burner plate 10 while reactant gas mixtures, including metal catalyst species of interest were fed through a central tube 12 . This configuration is termed a ‘pyrolysis flame’ in the papers as the central gas flow does not undergo combustion due to the lack of oxygen in this flow, but reactions (and nanotube formation) do proceed in the flow by virtue of the heating influence of the surrounding annular flame. The central gas flow is in effect a reactive streamtube and not a flame. A stabilizing chimney 14 (7.5×2.5 cm diameter) immersed in the flame gases provides a stabilizing effect and nanotube (single-wall, multi-wall nanotubes and nanofiber) samples are collected at the exit of the chimney. There are some important distinctions to note regarding this configuration. First of all, the outer (annular) flame is primarily a source of heat and the central gas mixture flow is the primary source of carbon and metallic catalyst. Combustion is not supported in the central gas flow. Therefore, heating and material synthesis processes are substantially separated functions.
A flame system has been used extensively in combination with a wide variety of methods to introduce metallic catalyst species to the system. Vander Wal and Ticich performed comparative experiments, synthesizing nanotubes in both the ‘pyrolysis flame’ and tube reactor setups (39, 40). The premixed flame in the outer annulus used acetylene/air mixtures of equivalence ratios between 1.4 and 1.62. The reactant gas mixtures used in this instance used either carbon monoxide/hydrogen or acetylene/hydrogen mixtures, and iron or nickel nanoparticles entrained in the central feed gases. In a similar study, Vander Wal and Ticich used a carbon monoxide/hydrogen reactant feed mixture and used a nebulized solution of iron colloid (ferrofluid) and a spray drying technique as the source of catalyst particles. Nanotube samples were collected once again at the exit of the chimney section (39). Single-walled nanotubes were observed in a similar flame setup where Vander Wal and Hall introduced metallocene (ferrocene and nickelocene) vapor to the central reactive feed gases using a controlled sublimation technique (45). Vander Wal observed single-walled nanotubes in an identical flame arrangement using a nebulizer system to introduce iron nitrate salt solution to the flame as the catalyst particle precursor (37). Vander Wal also reports the formation of nanofibers (similar to multi-walled nanotubes except the walls tend to be irregular and non-graphitic) in an identical flame configuration with nickel nitrate solution nebulized into the flame (44).
Another variation of the catalyst feed technique with this burner configuration is reported by Vander Wal, where catalyst particles are generated by burning a piece of paper coated in metal particles and the resulting aerosol is entrained in a fuel-rich mixture of carbon monoxide, hydrogen and air. The resulting gas mixture is fed to the central section of an annular fuel-rich acetylene-air flame and single-walled nanotubes are collected at the exit of a cylindrical chimney surrounding the central streamtube. In this instance the central gas flow does in fact lead to a premixed flame (as opposed to a pyrolysis reaction streamtube in previous experiments) where the premixed flame composition is carbon monoxide, hydrogen and air with entrained iron nano-particles. Single-wall nanotubes were once again collected at the exhaust of the stabilizing chimney (43). In this configuration, the premixed gas feed did not contain a hydrocarbon (carbon monoxide and hydrogen are used in this case). Further, the nanotube material is collected quite late in the system at a point exclusively at the exhaust of a physical chimney insert.
Vander Wal, Hall, and Berger have synthesized multi-walled nanotubes and nanofibers on cobalt nanoparticles supported on a metal substrate immersed in premixed flames of various hydrocarbon fuels and equivalence ratios (41, 42). This configuration is truly a premixed flame and all three functions necessary for nanotube synthesis (heat source, carbon source, and metal catalyst) are present in the same flame environment. However, in this instance the catalyst particles are supported on an externally affixed substrate immersed in the flame gases.
An extensive amount of research related to the formation of fullerenes and fullerenic nanostructures in flames has been reported in the last decade (46-48, 56, 58, 59). In particular, there have been two studies by Howard et al. where carbon nanotubes have been observed in condensed material collected from flames (47, 48). Howard et al. employed a premixed flame configuration operated at low pressure (20 to 97 Torr), and burner gas velocity between 25 and 50 cm/s. A variety of fuels and fuel/oxygen compositions (C/O ratios) were explored including acetylene (C/O 1.06, φ=2.65), benzene (C/O 0.86 to 1.00, φ=2.15 to 2.65) and ethylene (C/O 1.07, φ=3.21). Diluent concentrations between 0 and 44 mol % were also explored. These flames are all considered ‘sooting’ flames as they spontaneously generate condensed carbon in the form of soot agglomerates suspended in the flame gases. Similarly, other studies that have reported nanotubes in flames such as Duan et al. (54) and Richter et al. (55) have each been under sooting conditions. Samples of condensed material were obtained directly from the flame using a water-cooled gas extraction probe (between 2 to 7 cm above burner), and also from the water-cooled surfaces of the burner chamber. Nanostructures were extracted from the collected soot material by sonication of soot material dispersed in toluene. High resolution electron microscopy of the extracted material allowed visual analysis of the fullerenic nanostructures. A range of nanostructures was observed, including spherical, spheroidal, tubular and trigonous structures, typically composed of multiple, graphitic carbon planes. Nanotubes are observed in these materials and tend to be multi-walled nanotubes typically with more than 5 walls. The nanotube material is generally observed predominantly in the material collected from the chamber surfaces. U.S. Pat. No. 5,985,232 has been awarded for ‘production of fullerenic nanostructures’ that draws heavily on the methods and observations reported in the papers described above (46). The patent discloses a method based on a flame burning unsaturated hydrocarbons, operated at sub-atmospheric pressure (up to 300 Torr), with diluent present in the flame feed gases, and also makes allowance for the addition of metal species (such as iron, cobalt, nickel, calcium, magnesium, potassium, rubidium and strontium) to promote the formation of single-walled nanostructures. Additional disclosure relates to the potential of adding oxidant species to the flame gases to selectively purify the nanostructures relative to the soot material and possibly open the end-caps of nanotube materials.
There have been a number of combustion studies that have employed some components of the system described in the present patent application, yet did not observe the formation of carbon nanotube material. Rumminger et al. (60, 61) introduced a vapor of iron pentacarbonyl into premixed flames of methane/air and also carbon monoxide/hydrogen/air. The focus of the studies was on flame inhibition due to the compound. No nanotube material is reported from this work and the likely reason is the low equivalence ratio employed in these studies. Feitelberg and coworkers also injected metal compounds into premixed flames in order to examine the effect upon soot formation in fuel rich flames. Nanotube-like material was not reported from these studies, most likely because the equivalence ratios employed were too high. Janzen and Roth (62) examined the formation of iron-oxide particles in a premixed hydrogen/oxygen/argon flame injected with iron pentacarbonyl and did not observe any nanotube formation. The reason is very simply that there was insufficient carbon in this flame system. Each of these flame studies employed some, but not all, of the components that have been found to favor nanotube formation in a premixed flame.
SUMMARY OF THE INVENTION
In one aspect, the invention is a method for producing filamentary structures such as nanotubes including combusting hydrocarbon fuel and oxygen so as to establish a non-sooting pre-mixed or non-premixed flame and providing an unsupported catalyst to synthesize the filamentary structure in a post-flame region of the flame. The equivalence ratio, catalyst type and catalyst concentration may be selected to establish the non-sooting flame. In a preferred embodiment, residence time of the structures in the post-flame region of the flame extends up to approximately 200 milliseconds. It is preferred that a diluent such as argon be provided along with the hydrocarbon fuel and oxygen. It is also preferred that the catalyst be a metal in the form of an aerosol produced in the flame either by chemical reactions of a precursor compound such as iron pentacarbonyl and coagulation of the reaction products or by physical dispersion and mixing of pre-prepared catalyst particles.
In preferred embodiments, the filamentary structures are nanotubes each having a small diameter with either a metallic or semiconductor chirality. The invention further contemplates adding modifying agents such as ammonia, thiophene, hydrogen and carbon monoxide. A secondary oxidant may also be injected into the post-flame region so as to preferentially oxidize carbon or metallic contamination, or open filament structure.
In yet another embodiment, an electric and/or magnetic field may be impressed upon the flame or the post-flame region of the flame to alter residence time profiles and/or particle trajectories to alter filamentary structure and/or morphology. In one embodiment, an electric field having a selected strength is impressed upon the flame wherein the field lines are substantially parallel to the flame gas flow to induce preferential growth of the structures having either metallic or semiconductor chirality.
In yet another embodiment, an electric and/or magnetic field may be impressed upon the flame or the post-flame region of the flame to alter residence time profiles and/or particle trajectories to induce a separation effect. In one embodiment, an electric field having a selected strength is impressed upon the flame wherein the field lines are substantially perpendicular to flame gas flow to induce preferential separation of the structures from the flame gases.
In yet another aspect, the invention includes an apparatus for synthesizing filamentary structures having a burner system and a source of hydrocarbon fuel and oxygen delivered to the burner system to establish a non-sooting premixed or non-premixed flame A source of unsupported catalyst is provided to deliver the unsupported catalyst into the burner system. In a preferred embodiment, the burner system is designed to provide a selected residence time in a post-flame region in the burner system.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective, schematic view of a prior art experimental annular burner configuration.
FIG. 2 is a schematic illustration of the apparatus of the present invention.
FIG. 3 is a series of transmission electron microscope (TEM) images showing a progression of nanotube morphologies with increasing height above the burner (corresponding to increasing residence time).
FIG. 4 includes TEM images of samples collected for various equivalence ratios.
FIG. 5 is a TEM image showing a bundle of single-wall nanotubes.
FIG. 6 is a TEM image collected from a water-cooled chamber wall of the burner of the invention.
FIG. 7 is a graph of raman spectra for flame generated nanotube material.
FIG. 8 is a graph comparing spectra for flame generated material and material derived from plasma-arc processes.
FIG. 9 are scanning transmission electron microscope (STEM) images of a particle associated with a bundle of single-wall carbon nanotubes.
FIG. 10 is a graph, including TEM insets, showing improved nanotube quality and yield for equivalence ratios less than the sooting limit.
FIG. 11 is a graph, including TEM pictorial insets, illustrating how the non-sooting region enhances nanotube yield.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Definitions
The term ‘catalyst’ refers to particles introduced to the flame gases to initiate filamentary structure growth and control the nature of the formed structures.
The term ‘unsupported catalyst’ refers to catalyst particles (or precursor reagents that decompose to form components that coalesce and consequently form catalyst particles) that are introduced to the flame environment independent of any physical support affixed to a point or surface outside of the post-flame domain.
The term ‘filamentary structures’ refers to materials where there exists a dominant linear dimension, giving the structure of the material a filament-like or filamentary appearance. See also the definition of aspect ratio below.
The term ‘filamentary nanostructures’ refers to filamentary structures that have one or more dimensions on the scale of nanometers. Filamentary nanostructures include nanotubes, nanowires, nanocones, peapods, and nanofibers.
The term ‘fullerenic’ refers most specifically to an allotropic form of carbon that exhibits a three-dimensional curved structure comprising one or more layers or shells each including five- and sometimes seven-membered rings within a network of otherwise six-membered rings.
The term ‘nanotube’ implies a tubular structure of nanoscale dimensions. Nanotubes may be fullerenic in nature, implying they have end caps that close the surface of the structure, or may be tubular yet with end regions affixed to features (such as metal particles) other than curved end-caps, or the nanotubes may be open at one or multiple ends of the structure. More formally, there are essentially four categories that define the structure of nanotubes.
1. Single or multiwalled: Nanotubes can be considered as a graphitic plane rolled to form a cylinder. There are two main classes of carbon nanotubes. A single-walled nanotube (SWNT) is a single graphitic layer in the form of a tube. Multi-walled nanotubes (MWNT) consist of multiple layers arranged concentrically about a common axis. Double-walled nanotubes (DWNT) (63) are occasionally described as a distinct class, however they can be considered as the smallest category of MWNT. 2. Diameter: Single wall nanotubes have diameters of order 1 nm. Typical range of diameters spans from 0.7 nm (the diameter of C 60 ) through to 10 nm. The smallest observed nanotube diameter is 0.4 nm (4 Å) (64, 65). The diameter of multi-walled nanotubes varies between around 1 nm up to 100 nm. 3. Aspect ratio: One of the most striking properties of nanotubes is the disparity in their dimensions. The length of nanotubes can extend to order of microns and more, giving an aspect ratio (length to diameter) of 1000 to 1. The longest nanotubes reported to date (66) are 20 cm, giving an aspect ratio of 200,000,000 to 1! As used herein, filamentary structures have an aspect ratio of at least 10 to 1. 4. Chirality: The chirality of a nanotube refers to the ‘twist’ in the graphitic layer that makes up the tube wall. Certain chiralities can give metallic conduction while others are semiconductive. The chirality of a nanotube can be described uniquely by two indices (m,n). By folding a graphene sheet into a cylinder so that the beginning and end of a (m,n) lattice vector in the graphene plane join together, one obtains an (m,n) nanotube (4). (m,m) nanotubes are said to be ‘arm-chair’, (m,0) and (0,m) nanotubes are ‘zig-zag’, and (m,n) nanotubes are chiral. All arm-chair nanotubes are metallic but only one third of possible zig-zag and chiral nanotubes are metallic, the other two thirds being semiconducting (67).
The term ‘nanowire’ implies a linearly contiguous and non-hollow length of metal based material with diameter on a scale of nanometers. Nanowires can be formed by filling the internal cavity of carbon nanotubes with metals and other elements.
The term ‘nanocone’ refers to a class of materials that have a dominant linear dimension with a non-constant diameter increasing or decreasing relative to the position along the length of the structure.
The term ‘peapod’ refers to carbon nanotubes that have one or more carbon fullerenes occupying the internal cavity of the nanotube.
The term ‘nanofiber’ refers to filamental structures that are similar in structure to multi-walled nanotubes as they possess multiple structural layers in the wall area. Nanofibers are much more disordered and irregular relative to nanotubes and the walls are non-graphitic. Carbon nanofibers may alternately be described as carbon fibrils, vapor grown carbon fibers (VGCF), filamental carbon, filamental coke or simply filaments.
The term ‘graphitic’ refers most specifically to an allotropic form of carbon that exhibits a flat, two-dimensional, planar structure. The term graphitic in the context of this document refers to the flat geometric structure and the high degree of order associated with a planar structure, and does not necessarily imply an elemental composition of carbon. A graphitic plane rolled into a cylinder can therefore describe the structure of a single-walled nanotube.
The term ‘post-flame region or zone’ is the part of the flame located downstream of, or farther from a burner than, the oxidation region or zone of the flame. The beginning of the post-flame region is marked by the approximate completion of the consumption of molecular oxygen and the conversion of the original fuel to intermediates and products including carbon monoxide, carbon dioxide, acetylene, other carbon containing species, hydrogen and water. The post-flame region includes the tail of the flame, extends to the transition between the flame and the exhaust, and consists of hot but usually cooling gases which are approximately well mixed within a given cross section of the flow perpendicular to the direction of flow at a given distance from the burner. The well-mixed condition is achieved by mixing the fuel and oxygen together before feeding them to the burner (premixed combustion) or by feeding the fuel and oxygen as separate streams which rapidly mix within the combustor over a downstream distance from the burner that is much smaller than the diameter or the equivalent diameter of the post flame region (non-premixed combustion). The residence time in the post-flame region is much larger than the residence time in the oxidation region of premixed flames or the mixing and oxidation region of non-premixed flames.
The term ‘sooting flame’ refers to a flame system including a fuel and oxygen undergoing combustion in such a way that carbon soot is generated in visibly significant quantities. Almost all non-premixed flames of hydrocarbon fuels exhibit soot formation. The sooting limit for premixed flames is defined as the lowest equivalence ratio (or carbon to oxygen ratio) at which soot is observed in the flame gases. A sooting flame has a distinctive, visibly luminous glow caused by emission from the soot particles. A non-sooting flame is established by a fuel equivalence ratio (or carbon to oxygen ratio) lower than the sooting limit.
Addition of metal bearing compounds to the flame may induce visible luminosity yet the flame is not sooting as in this instance the sooting limit is defined for the base-flame (fuel, oxygen only). For non-sooting flames the radiance is caused by emission from the metal particles rather than soot particles.
In flames containing nanotube formation catalysts, the critical equivalence ratio for soot formation depends not only on equivalence ratio, but also on the type and concentration of catalysts present. Metal catalysts may augment soot formation such that a non-sooting condition may become sooting upon catalysts addition if the flame were at an equivalence ratio near the sooting limit and the type and concentration of catalyst added were sufficient.
Burner System
A premixed acetylene/oxygen/argon flame formed the basis of the experiments disclosed in this patent application. An argon dilution of 15 molar percent, cold gas feed velocity of 30 cm/s, and burner pressure of 50 Torr were used throughout the experiments. A variety of fuel equivalence ratios ranging from 1.4 through 2.2 were considered. Iron pentacarbonyl (Fe(CO) 5 ) was used as the source of metallic catalyst necessary for nanotube synthesis.
With reference to FIG. 2 , a controlled flow of iron pentacarbonyl vapor was supplied through a temperature-controlled (4° C.) single-stage bubble saturator 20 unit using argon as the carrying gas. The argon gas flow could be accurately proportioned between the saturator 20 and a bypass line, allowing control of the catalyst feed rate. Typical iron pentacarbonyl feed concentrations were 6000 ppm (molar).
A burner 22 consisted of a 100 mm diameter copper plate 24 with 1500 uniformly spaced 1 mm diameter holes drilled through the surface. Only the inner 70 mm diameter burner section was utilized for this study with the outer annular section used during flame startup. The burner plate 24 is attached to a burner cavity filled with stainless steel wool to facilitate uniform flow distribution of premixed gases 25 entering from the base of the cavity. Suitable premixed gases include acetylene, oxygen and argon. It is also contemplated that modifying agents for altering the structure or morphology of the condensed material may be co-injected. In addition, a secondary oxidant may be injected in the post-flame region to oxidize carbon contamination. It is also contemplated to quench the filamentary structures by injecting an inert fluid that will quench by sensible energy, latent energy or chemical reaction. A flow of cooling water passes through copper tubing 26 coiled around the outside of the burner body. Burner plate temperatures were typically 70-80° C. The burner was mounted on a vertical translation stage 28 , which allows measurements to be taken at various heights-above-burner (HAB). The burner 22 and translation stage 28 are contained in a stainless-steel pressure chamber 30 . An upper chamber plate is water-cooled and exhaust gases are withdrawn through two ports 32 in the upper flange. A variety of ports in the sidewall of the chamber provide access to sampling and diagnostic instruments. A large (15 cm) window 34 is provided for visual observation of the flame (68). An electronic proportioning valve 36 and PID controller coupled to the exhaust extraction system allows accurate control of the chamber pressure.
Table 1 shows operational settings and parameters to obtain good quality nanotubes.
TABLE 1
Table 1: Operational settings to obtain good quality nanotubes
Parameter
Setting
Fuel
Acetylene
C 2 H 2
Oxidant
Oxygen
O 2
Diluent
Argon
Ar
Metal species
Iron pentacarbonyl
Fe(CO) 5
Equivalence ratio (φ)
1.6 (non-sooting)
(±0.02)
C/O ratio
0.65
(±0.02)
Chamber pressure
50 Torr (0.066 atm)
(±0.5)
Gas velocity at burner (@298 K)
30 cm/s
(±2)
Metal concentration in feed
6,000 ppm (mole)
(±1000)
Diluent concentration
18 mole %
(±3)
Sample location
Good quality material for heights
above burner (HAB) >50 mm
Temperature profile
1800 K at 10 mm
(±100)
1500 K at 80 mm
(±100)
With reference still to FIG. 2 , a preferred embodiment includes an electric field represented by the arrow 27 aligned with flame gas flow and having a selected field strength. Those skilled in the art will recognize that the electric field 27 could also be a magnetic field or the combination of an electric and magnetic field to alter the characteristics of the filamentary structures produced. For example, an electric and/or magnetic field may be used to alter residence time profiles and/or particle trajectories to alter the structure or morphology of the produced structures. The electric field 27 aligned with the flame gas flow will induce preferential growth of the structures with either metallic or semiconductor chirality.
Sampling System
A thermophoretic sampling technique (69) was used to collect condensed material in the flame gases at various HAB and the samples were then analyzed using transmission electron microscopy (TEM). A thermophoretic sampling system 38 included a pneumatic piston coupled with a timing mechanism to give precise control over immersion time within the flame. An insertion time of 250 ms was used throughout the experiments. TEM grids 40 (Ladd Research Industries, 3 mm Lacy film) were affixed to a thin metal stage attached via a 6 mm diameter rod and pressure seal feedthrough to a pneumatic plunger. After insertion into the flame gases, each TEM grid was removed and subsequently taken to the microscope for analysis. A JOEL 200CX was used for the bulk of the microscopy work to allow rapid screening and turnaround of samples to be examined. More detailed microscopy was performed on a 2010 and 2000FX for high resolution images.
Scanning Transmission Electron Microscopy (STEM)
The elemental composition of any condensed material is of particular interest in terms of the nanotube formation processes occurring in the flame. STEM combined with electron dispersive x-ray spectroscopy (EDXS) allows a high resolution transmission electron microscopy image to be correlated with an elemental map that gives insight into the distribution of specific elements (such as C, Fe, O) relative to the material structures imaged using TEM. A VG HB603 system was used for STEM analysis performed in this study.
Raman Spectroscopy
Raman spectroscopy can be used to obtain information relating to the diameter and also the chirality of single-walled carbon nanotubes (70, 71). When single-wall nanotubes are irradiated with 514.5 nm argon-ion laser light, at least two distinct resonant modes are observed in the resulting Raman spectrum. Modes around the 100 to 300 cm −1 frequency range correspond to the ‘radial breathing mode’ (RBM) of nanotubes where the cylindrical nanotube vibrates in a concentric expansion and contraction. The frequency of the RBM is inversely proportional to tube diameter and so the spectrum can be used to obtain tube diameter information. The second major feature in the spectrum is the ‘G-band’ at around 1590 cm −1 which corresponds to transverse vibrations along the plane of the nanotube wall. Shifts in the shape of the G-band peak can indicate the nature of the nanotube chirality (semiconducting or metallic). Raman spectroscopy on condensed samples collected from the burner chamber wall was performed using a Kaiser Hololab 5000R Raman spectrometer with Raman microprobe attachment. The spectrometer was operated at 514.5 nm at 0.85 mW power in stokes configuration.
Synthesis Dynamics Characterization
Thermophoretic samples were taken at regular height intervals above the burner 22 and images obtained using transmission electron microscopy. Each sampling height corresponds to a residence time away from the burner and so this technique enables characterization of the dynamics of the nanotube growth processes occurring in the flame. Flame characterization sampling was performed on flames with equivalence ratios (φ) between 1.4 and 2.2. For each flame, samples were obtained along the axis-line in the post-flame region between 10 and 75 mm above the burner. A typical progression of nanotube morphologies observed in a flame with equivalence ratio of 1.6 is shown in FIG. 3 .
The initial post-flame region (up to 40 mm) as shown in FIG. 3 is dominated by the presence of discrete particles. Particle formation and growth leads to larger particle sizes as height above burner increases. Iron pentacarbonyl decomposes rapidly upon exposure to the flame and the particles size growth most likely occurs through coagulation of the iron resulting from this decomposition (62). The composition of the particles is most likely metallic iron as observed in flames of higher equivalence ratio (72).
Nanotube growth is generally accepted to occur through a decomposition-diffusion-precipitation mechanism whereby carbon bearing species (primarily CO) catalytically decompose on the surface of a metal particle, followed by elemental carbon dissolving into the metal lattice and diffusing to the adjacent side of the particle, where the carbon precipitates in a curved tubular graphitic structure (73-75). Based on this mechanism it is likely that catalytic decomposition and ‘loading’ of carbon into the particles is also occurring concurrently with particle growth in this initial post-flame region.
Carbon nanotubes are observed after an inception time of approximately 30 milliseconds. A small number of discrete nanotube segments with length of the order of 100 nm are observed as early as 25 ms and longer tube lengths up to a micron in length are observed to form in the following 10 ms. It appears that the metallic particle population has reached a critical level after 25 ms and nanotube growth proceeds rapidly after this point for the next 10 to 20 ms. The critical condition may be sufficiently large particle size, carbon content, surface properties, internal lattice structure transition (41), or point of relative concentrations for CO and H 2 within the flame gases (42).
For times after 40 ms the dominant mechanism appears to be coalescence of the condensed material in the flame gases. Disordered networks of nanotube bundles form tangled webs decorated with metallic and soot-like particles. The complexity and size of the webs increases significantly in the upper region of the system, between 45 and 70 ms.
From the structures observed in the post-flame gases it is clear that, once initiated, nanotube growth occurs quite rapidly. An order of magnitude estimate for the nanotube growth rate is 100 μm/s based on the images and observed increase in length of 100 nm to 1 micron over a period of 10 ms (between 25 to 35 ms).
Nanotube Formation Window
The effect of different equivalence ratios upon nanotube formation was also investigated. Samples were extracted from 70 mm above burner (approx. 67 ms) for equivalence ratios between 1.4 and 2.0. Representative TEM images over the range of equivalence ratios are shown in FIG. 4 . Nanotubes are observed to form between equivalence ratios of 1.5 and 1.9. This range of equivalence ratios can be considered as a ‘formation window’ where conditions within the flame are suitable for nanotube synthesis. A particularly preferred equivalence ratio range is 1.5≦φ<1.7. For low equivalence ratios (1.4 and 1.5) the condensed material in the flame is dominated by discrete particles, although nanotubes may form at higher HAB than those described in the present system (See FIG. 11 ). The range of equivalence ratios that could support nanotube growth can therefore potentially extend from 1.7 to 1.0. Equivalence ratios of 1.9 and higher are dominated by soot-like structures displaying clustered networks of primary particles (of either metallic or carbon encapsulated metal centers) with the occasional nanotube within this matrix. It is interesting to note that within the formation window range, relatively ‘clean’ nanotubes are formed at the lower equivalence ratios while an increasing level of encrusting with disordered carbon is observed on the nanotubes as the equivalence ratio increases.
A continuum of morphologies is apparent ranging between clean nanotubes at low equivalence ratios through to an increasing proportion of soot-like material as the equivalence ratio increases. A competition between carbon precipitation pathways is likely, with one pathway leading to filamentary or tube structures and the other to disordered carbon clusters. This observation is consistent with the nanotube formation mechanism and how this would relate to a flame environment. As fuel equivalence ratio increases from unity, the level of excess carbon available in the flame gases increases, so one would also expect an increasing potential to form carbon nanotubes. This trend is tempered as the sooting equivalence ratio limit is reached and the availability of carbon exceeds the capacity of the nanotube formation pathway and disordered carbon is formed. Therefore the lower formation limit corresponds to insufficient availability of carbon, while the upper limit is due to dominance of soot formation pathways close to the sooting limit.
The observed change in morphology as equivalence ratio is changed is described quantitatively in FIG. 10 . A metric of nanotube quality, defined in this instance as the product of filament length and filaments counted in a TEM image divided by the image area covered by condensed material. High quality material by this metric would have many filaments of significant length within a matrix of minimal non-structured condensed material. A plot of this metric against equivalence ratio indicates quite clearly that nanotube quality improves dramatically as equivalence ratio moves from high (2.0+) to lower equivalence ratios. This trend reinforces the importance of using non-sooting flames to enhance the growth of filamental structures in the flame. Furthermore, the TEM insets and schematic plot give context to this phenomena relative to other flame parameters.
Material Characterization
Higher magnification TEM analysis shows that the condensed filamental material is predominantly bundles of single-wall nanotubes ( FIG. 5 ). The structures shown in FIG. 5 resulted from an equivalence ratio of 1.6 with a HAB of 70 mm. The inset shows detail of a nanotube bundle with an outer wall shown in dark contrast. The flame synthesis process preferentially forms single-wall as opposed to multi-wall nanotubes. This observation is in agreement with other flame studies (43) and indicates a high degree of selectivity in the material synthesis despite the ensemble of competing processes occurring in the flame system. A TEM image for material collected from the water-cooled chamber wall (used for Raman measurements also) is shown in FIG. 6 . Note the dominant features of nanotube bundles encrusted with agglomerates of carbon with internal metallic particles.
The Raman spectroscopy technique yielded a number of observations about the flame generated nanotube material. A typical Raman spectrum for flame generated material is shown in FIG. 7 . Spectra for flame generated material (bold line) are compared to materials obtained from plasma arc processes (light grey lines) in FIG. 8 . In FIG. 7 , features centered around 200 cm −1 are radial breathing modes corresponding to a range of single-walled nanotube diameters (approximately 0.9 to 1.3 nm). The shape of the large peak at 1590 cm −1 relates to chirality effects. The Raman spectrum for the flame generated material shows a wide distribution of peaks corresponding to radial breathing modes (RBM). The corresponding range of tube diameters that generate this spectrum are between approximately 0.9 and 1.3 nm. When compared to the RBM modes obtained from the spectra of material generated with a plasma-arc technique, a difference in diameter distribution is clear. The flame generated material has a broader distribution of diameters and the diameters extend to smaller sizes. Other differences are apparent based on the shape of the G-band. The flame generated material has a significant ‘hump’ profile on the side of the G-band, with a peak at about 1330 cm −1 and an apparent peak seen as a shoulder on the G-band, which is indicative of nanotube chirality (semiconducting or metallic). Compared to the plasma-arc generated material, the flame material appears to be more metallic in nature.
Scanning transmission electron microscopy (STEM) was performed on material sampled directly from the flame as per the previously described TEM measurements. The composition of the particles associated with the carbon nanotubes is of particular interest and electron dispersive x-ray spectroscopy (EDXS) was used in scanning mode to obtain spatial maps of elemental intensity which could be compared to the STEM image in order to correlate composition with position. Images for this measurement on flame generated material are shown in FIG. 9 . The STEM bright field image shows a bundle of single-wall carbon nanotubes with a dark particle agglomerate overlaying the bundle (apparently sitting next to rather than a part of the bundle). The elemental map for iron clearly shows a close correlation between the iron and the particle position, indicating the particle is composed largely of iron. The oxygen map also shows a correlation although at much lower intensity. The particle is most likely predominantly iron but may have a small oxide content. The carbon map shows rather poor contrast due to the bundle sitting on a carbon substrate yet an increased carbon intensity is observed in correlation with the nanotube bundle and around the particle. The particle associated with the nanotube bundle is likely composed of iron surrounded by non-structured carbon, as can also be observed in TEM images shown in FIGS. 5 and 6 .
Nanotube Yield & Purity
The yield of nanotube material from the flame was estimated by a probe sampling technique and gravimetric analysis. A quartz tube (OD 11 mm, ID 9 mm), surrounded by a water cooled jacket, was inserted into the post-flame region with the mouth opening of the probe positioned 70 mm above the burner surface. The quartz tube was attached directly to a sintered metal filter assembly (Swagelok) that had been modified by placing a custom made disc of filter fabric (Balston, grade CQ) in-line before the metal filter disc. A vacuum pump was coupled to the filter to allow extraction of flame gases and flame-born condensed material through the probe and filter unit. Sampled gases were vented from the sample pump exhaust directly to a water column (gas collection bell) to allow determination of the volumetric concentration in the flame. After sampling the flame for a measured period of time, the filter disc was removed from the filter unit and weighed to determine the mass of material collected.
The amount of condensed material collected on the filter, scaled to the cross-section area of the burner face, over the sampling time (90 sec), gave the following estimates for condensed material yield per component of burner feed (per C fed: 1.1%; per Fe fed 24.8%; per Fe(CO) 5 fed 9.8%). Based on inspection of representative TEM micrographs for the flame sampled material ( FIG. 6 ), it is estimated that roughly 50% of the image area covered by condensed material is associated with nanotubes (typically in the form of bundles) and this would equate roughly to a mass percentage of 10% or so. The yield of nanotubes relative to components fed to the burner can therefore be estimated as (per C fed 0.1%; per Fe fed 2.5%; per Fe(CO) 5 fed 1.0%). These estimated yields indicate that there are significant quantities of nanotubes generated in the flames described in this study, and would certainly amount to more than 1% of the condensed material.
The effect of using non-sooting flames is illustrated in FIG. 10 . Nanotube quality and yield as a proportion of condensed material clearly improves as equivalence ratios shift away from the sooting limit. Note that yield of the filamentary material peaks at an equivalence ratio of approximately 1.6. However, it is likely that higher yields may be obtained at lower equivalence ratios and higher HAB (or longer residence times) as is indicated in FIG. 11 .
Single-walled nanotubes have thus been observed in a premixed acetylene/oxygen/argon flame operated at 50 Torr with iron pentacarbonyl vapor used as a source of metallic catalyst necessary for nanotube growth. A thermophoretic sampling method and transmission electron microscopy were used to characterize the solid material present at various heights above burner (HAB), giving resolution of formation dynamics within the flame system. Catalyst particle formation and growth is observed in the immediate post-flame region, 10 to 40 mm HAB, with coagulation leading to typical particle sizes on the order of 5 to 10 nm. Nanotubes were observed to be present after 40 mm (˜34 ms) with nanotube inception occurring as early as 30 mm HAB (˜25 ms). Between 40 and 70 mm HAB (period of approx. 30 ms), nanotubes are observed to form and coalesce into clusters. Based on the rapid appearance of nanotubes in this region, it appears that once initiated, nanotube growth occurs quite rapidly, on the order of 100 μm per second. A nanotube formation ‘window’ is evident with formation limited to fuel equivalence ratios between a lower limit of 1.5 and an upper limit of 1.9, although this range may extend to lower equivalence ratios in samples withdrawn from higher (or after more time) in the post-flame region. A continuum of morphologies ranging from relatively clean clusters of nanotubes to disordered material is observed between the lower and upper limits. The yield of nanotubes in the condensed material increases at compositions lower than the sooting limit.
It is recognized that modifications and variations of the invention disclosed herein will occur to those skilled in the art and it is intended that all of such modifications and variations be included within the scope of the appended claims.
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Method and apparatus for producing filamentary structures. The structures include single-walled nanotubes. The method includes combusting hydrocarbon fuel and oxygen to establish a non-sooting flame and providing an unsupported catalyst to synthesize the filamentary structure in a post-flame region of the flame. Residence time is selected to favor filamentary structure growth.
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FIELD OF THE INVENTION
[0001] The invention relates to an improved releasing slip for use with a hold down tool/bridge plug/packer for lowering into a wellbore. In particular, the releasing slip of the invention has a low friction face to facilitate ease of release.
BACKGROUND OF THE INVENTION
[0002] A production packer is a standard component of completion hardware in oil and gas wells. Production packers are used to provide a seal between the outside of production tubing and the inside of a casing, liner, or wellbore wall. When recovering oil and gas from a well, in many geological formations it is necessary to isolate the zone containing the oil and gas producing formation from the remainder of the underground structure so as to prevent contamination of the oil and gas producing zone from salt water or other undesirable contaminants.
[0003] Packers may be lowered into the well and expanded to isolate the oil and gas producing zone. Packers may be placed above and below the producing zone, or, if the producing zone is near the bottom of the well, a single packer may be placed above the producing zone. Packers are typically provided with slips for providing gripping engagement with the wall of a wellbore. Once a packer is set, the packer may experience forces that could displace the packer in the casing. One example of such a force is pressure from the formation.
[0004] In some circumstances, it may be desirable to utilize a hold down tool or bridge plug in the well to assist in keeping a packer in position. A hold down tool/bridge plug typically includes a plurality of slips that may be selectively forced into tight engagement with a wall of the well bore.
[0005] One difficulty associated with the use of conventional slips or gripping members is that the slips that are engaged with the wellbore can be extremely difficult to release when it is desired to release the tool.
[0006] An innovative oil well hold down tool is taught in U.S. Pat. No. 3,356,141 to Albert K. Kline (the '141 patent). The system taught in the '141 patent provided for one or more slips to be released prior to release of all the loaded slips, depending on the circumference of the tool used. The early releasing slips have become known as “releasing slips”. When the releasing slip or slips are released, normally by pulling up against them or their mounting device, the tool as a whole is then free to move laterally in the well slightly. The lateral movement of the tool is enough to lessen or remove entirely the bite of the remaining slips. The tool can then be moved up the well, or relatched and then moved further down the well and reset, or removed entirely.
[0007] There are numerous uses of the releasing slip principle taught by the '141 patent. Applicant's company manufactures several tools utilizing the teachings of the '141 patent. For example, one tool addressed improvements to the invention of the '141 patent related to the releasing slips. The device was used to assist in the release of hold down tools that have mechanically, as opposed to hydraulically, loaded slips above the pack-off portion of the tool.
[0008] One drawback of hold down tools utilizing prior art designs is that, when engaged, the slips bite into the casing wall while the hold down tool is performing its functions. Therefore, during release, even the releasing slips provide resistance, which causes problems including that the biting surfaces of the releasing slips become worn fairly quickly, requiring their replacement. An additional difficulty is that during higher pressure operations, the releasing slips can provide sufficient resistance that release becomes difficult and may also cause other problems. These problems may include overstressing the pulling unit topside, parting of the tubing that is used to transfer the tension from the pulling unit to the tool, rupture or permanent deformation of the mounting device for the slips, and ultimately, an inability to remove the tool at all.
SUMMARY OF THE INVENTION
[0009] This present invention replaces the releasing slips with a part or parts that have no biting effect on the casing. In one embodiment, the surface of the releasing slip of the present invention is entirely smooth. When pulled upwards, the releasing slips of the present invention move up much more easily, allowing the tool to move laterally, thereby partially unloading the remaining slips, and thus allowing the remaining slips to more easily release. The releasing slips in this case are, in practice, used as a wedge, which allow the remaining slips to function normally. The releasing slips of the invention are not required to provide biting capability for the hold down tool to perform its function. The releasing slips of the invention allow the tool to release much more easily, especially in severe applications.
[0010] A second embodiment of the present invention utilizes one or more hardened carbide pieces or other suitable material on the contacting face of the releasing slip of the invention. The smooth surface of the hardened piece or pieces are preferably configured such that the piece or pieces lay flat against a wall, thereby providing greatly reduced resistance to release. The carbide pieces are harder than any standard grade of casing, which greatly reduces wear on the part.
[0011] In the case of larger diameter tools, more than one releasing slip may be used in the circumferential arrangement of the upper slips. Preferably, the releasing slips cover somewhat less than half the circumference of the tool so that the tool can move laterally in the wellbore when the releasing slips are released or disengaged from the wellbore wall. The biting slips preferably also encompass less than half the circumference. As an example, a hold down tool of the present invention may use two releasing slips and four biting slips, although other numbers of slips and ratios of releasing slips to biting slips may be functional. In a preferred embodiment, the releasing slips are wider than the biting slips and the biting slips encompass less than 180 degrees of tool circumference.
[0012] There are several advantages of the present invention. Most importantly, a tool utilizing the inventive slips significantly reduces the problems described above with respect to removal of the tool. The monetary benefit associated with the tool includes the relatively smaller benefits associated with improved service life of the releasing slips and also the substantially larger benefits associated with avoiding an inability to release the tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a partially sectioned elevation view of a packer being placed in a hole, attached to a hold down tool, in which the invention is embodied.
[0014] FIG. 2 is the structure of FIG. 1 attached at a desired position within a well bore.
[0015] FIG. 3 is an isometric view of a slip housing base of the hold down tool of FIG. 1 .
[0016] FIG. 4 is an isometric view of the slip housing of FIG. 3 shown with slips installed therein.
[0017] FIG. 5 is an isometric view of a biting slip for installation into the slip housing of FIG. 4 ,
[0018] FIG. 6 is an isometric view of a releasing slip for installation into the slip housing of FIG. 4 .
[0019] FIG. 7 is an isometric view of a releasing slip of FIG. 4 with carbide pieces on a wall engaging face of the releasing slip.
[0020] FIG. 8 is a partial cut-away view of a retrievable bridge plug in which the invention is embodied.
[0021] FIG. 9 is a partial cut-away view of a packer in which the invention is embodied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Referring first primarily to FIGS. 1 and 2 , shown is well bore 10 having a wall 12 . A packer 14 is shown lowered into well bore 10 . Packer 14 includes an expansible element such as packer slips 15 for selectively engaging wall 12 . A hold down tool 16 is connected to packer 14 . Hold down tool 16 includes a cone assembly 18 . Cone assembly 18 has an upwardly facing cone 20 and an outer casing 22 . Outer casing 22 defines a j-slot 24 having a long vertical section 26 and a short horizontal section 28 . Cone assembly 18 further defines an internal abutment 30 .
[0023] A coupling member 32 is attached to an upper end of hold down tool 16 . A tubing string 34 is connected to coupling member 32 for supporting hold down tool 16 and packer 14 within well bore 10 .
[0024] A spring 36 is located above hold down tool 16 . Spring 36 has an upper end in abutment with coupling member 32 . A cylindrical mandrel 38 extends downwardly inside cone assembly 18 . Mandrel 38 defines a protuberance 40 and has a lower end 42 . Mandrel 38 further has a pin 44 protruding from an outer surface. Pin 44 is provided for extending into j-slot 24 .
[0025] Mandrel 38 and cone assembly 18 are releasably connected together via pin 44 and j-slot 24 . When pin 44 is positioned in long vertical section 26 of j-slot 24 , mandrel 38 may be moved downwardly (as shown in FIG. 2 ) until lower end 42 of mandrel 38 seats on internal abutment 30 of cone assembly 18 .
[0026] Slip housing 46 is located above cone assembly 18 . Slip housing 46 is made up of a slip housing cover 48 ( FIGS. 1 , 2 , 4 ) and a slip housing base 50 ( FIGS. 3 , 4 ). Slip housing base 50 is slidably mounted on mandrel 38 . Slip housing cover 48 and slip housing base 50 define an annular space therebetween. Slip housing base 50 has an upper end in engagement with a lower end of spring 36 . Spring 36 urges slip housing base 50 against protuberance 40 on mandrel 38 . Slip housing base 50 has a lower end defining a flange portion 52 . Flange portion 52 defines a plurality of downwardly facing openings 54 ( FIG. 3 ).
[0027] A plurality of slips 56 are carried within slip housing 46 and are sized to be received within openings 54 of slip housing base 50 . Slips 56 each have an extension 58 ( FIGS. 4-7 ) on an upper end for locating in the annular space between the slip housing cover 48 and the slip housing base 50 . Slips also have a wall engaging face 60 ( FIGS. 4-7 ). Slips 56 further define a slip neck 61 ( FIGS. 5-7 ). Slips 56 are loosely received within openings 54 of slip housing base 50 wherein flange portions 52 of slip housing base 50 that are located between openings 54 provide supportive engagement with slip necks 61 .
[0028] Slips 56 are comprised of biting slips 62 ( FIGS. 4 , 5 ) and releasing slips 66 ( FIGS. 4 , 6 , 7 ). Faces 60 of biting slips 62 have a plurality of wickers or teeth 64 to facilitate gripping engagement with wall 12 of bore 10 . Faces 60 of releasing slips 66 have smooth surface 68 to facilitate ease of release. In an alternative embodiment, smooth surface 68 of releasing slip 66 may be impregnated with one or more hardened carbide pieces 70 to reduce wear on face 60 of releasing slips 66 .
[0029] Slip housing base 50 functions to selectively urge slips 56 downwardly when mandrel 38 is moved downwardly. Slips 56 are oriented vertically and are positioned circumferentially above upwardly facing cone 20 of hold down tool 16 . Therefore, when slips 56 are moved downwardly with mandrel 38 , slips 56 engage the upwardly facing cone 20 . Upwardly facing cone 20 then forces engagement faces 60 proximate the lower ends of slips 56 outwardly into engagement with wall 12 of well bore 10 .
[0030] When it is desired to release the slips 56 , mandrel 38 is moved upwards. The force of the mandrel moving upward is first transmitted through slip housing base 50 . Flange portion 52 of slip housing base 50 lifts slips 56 upwards. Slip necks 61 may be of different lengths, so that flange portion 52 does not engage slips simultaneously.
[0031] Referring now to FIG. 8 , a bridge plug 100 is shown utilizing the slips of the invention. Bridge plug 100 includes a tubular housing 102 . Tubular housing 102 is made up of lower mandrel 104 , connecting rod 106 that is threadably received on an upper rod of lower mandrel 104 , and an upper mandrel 108 that is threadably received on an upper end of connecting rod 106 . A pulling head cap 110 is threadably received on an upper end of upper mandrel 108 .
[0032] A control body 112 surrounds lower mandrel 104 . A plurality of drag blocks 114 are supported by control body 112 . Drag blocks 114 are biased outwardly by drag block springs 116 .
[0033] A lower cone member 118 surrounds lower mandrel 104 . Lower cone member 118 has a cone section 120 and a lower cylindrical section 122 . A plurality of lower slips 124 surround lower cylindrical section 122 of lower cone member 118 . Plurality of lower slips 124 are located below cone section 120 of lower cone member 118 .
[0034] An element retainer 126 is threadably received on an upper end of lower cone member 118 . Packing and seal sleeve 128 and attached packing element 130 are adjacent to connecting rod 106 in an abutment with element retainer 126 . An upper cone member 132 is threadably received on an upper end of packing and seal sleeve 128 .
[0035] A slip sleeve 134 is provided above upper cone member 132 . A plurality of upper slips 136 surrounds slip sleeve 134 . Upper slips 136 are made up of releasing slips 138 and biting slips 140 . A thrust spring 142 is provided having a lower end in engagement with slip sleeve 134 . A spring ring 144 is affixed to upper mandrel 108 . Spring ring 144 is in engagement with an upper end of thrust spring 142 .
[0036] In practice, when packing element 130 engages a wall of a wellbore, packing element 130 moves upwardly with regard to tubular housing 102 with attached upper cone member 132 . Upper cone member 132 contacts upper slips 136 and forces slips 136 into engagement with a wall of the wellbore.
[0037] Referring now to FIG. 9 , shown is a packer 200 utilizing the releasing slips of the invention. Packer 200 includes a mandrel 202 . A top sub 204 is threadably attached to an upper end of mandrel 202 . A control body 206 surrounds mandrel 202 . A plurality of drag blocks 208 are supported by control body 206 . Drag blocks 208 are biased outwardly by drag block springs 210 .
[0038] A lower slip sleeve 212 is threadably attached to an upper end of control body 206 . A lower cone member 214 surrounds lower slip sleeve 212 . A plurality of lower slips 216 surround lower slip sleeve 212 . The plurality of lower slips 216 are located below lower cone member 214 .
[0039] An element retainer 218 is threadably received on an upper end of lower cone member 214 . A packing and seal sleeve 220 as well as a packing element 222 are in threaded communication with element retainer 218 .
[0040] An upper cone member 224 is threadably received on an upper end of packing and seal sleeve 220 . An upper slip support 226 is located above upper cone member 224 . A plurality of upper slips 228 surround upper slip support 226 . Upper slips 228 are made up of releasing slips 230 and biting slips 232 . A slip spring 234 is provided for biasing each of upper slips 228 outwardly. An upper slip housing assembly 236 is located above upper slips 228 .
[0041] In practice, when packing element 222 engages a wall of the wellbore, packing element 222 moves upwardly with regard to mandrel 202 . Attached upper cone member 224 moves upwards as well. Upper cone member 224 contacts upper slips 228 and forces slips 228 into engagement with a wall of the wellbore.
[0042] When pulled against for release, as described above, releasing slips 66 ( FIGS. 4 , 6 , 7 ), 138 ( FIG. 8 ), 230 ( FIG. 9 ) are easily lifted and disengaged from wall 12 since releasing slips 66 , 138 , 230 have a low friction wall engaging face, as can best be seen in FIGS. 6 and 7 . Once releasing slips 66 , 138 , 230 are lifted, tool 16 , 100 , 200 is able to move laterally, thereby partially unloading the remaining biting slips 62 ( FIGS. 4 , 5 ), 140 (FIG, 8 ), 232 ( FIG. 9 ), which allows biting slips 62 , 140 , 232 to more easily release. Therefore, releasing slips 66 , 138 , 230 function as a wedge to force biting slips 62 , 140 , 232 to securely engage wall 12 . Releasing slips 66 , 138 , 230 are not required to provide biting capability for tool 16 , 100 , 200 to perform its function. Releasing slips 66 , 138 , 230 of the invention allow tool 16 ( FIGS. 1 , 2 ), 100 ( FIG. 8 ), 200 ( FIG. 9 ) to release much more easily, especially in severe applications.
[0043] In one embodiment, hardened pieces 70 ( FIG. 7 ), such as hardened carbide disks or pieces of other suitable material protrude from contacting face 60 of releasing slip 66 , or from a contact face of releasing slips 138 , 230 . Smooth surface 68 of a hardened piece 70 or pieces 70 are preferably configured such that the piece or pieces 70 lay flat against wall 12 , thereby providing greatly reduced resistance to release. The carbide pieces 70 are harder than any standard grade of casing, which greatly reduces wear on releasing slip or slips 66 , 138 , 230 .
[0044] In the case of larger diameter tools 16 , 100 , 200 , more than one releasing slip 66 , 138 , 230 may be used in the circumferential arrangement of the slips 56 . Preferably, releasing slips 66 , 138 , 230 cover somewhat less than half the circumference of tool 16 , 100 , 200 , so that tool 16 , 100 , 200 can move laterally in wellbore 10 when releasing slips 66 , 138 , 230 are released or disengaged from wall 12 . Consequently, biting slips 62 , 140 , 232 preferably encompass more than half the circumference of tool 16 , 100 , 200 .
[0045] Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.
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Releasing slips for use with a downhole tool, a tool for deploying downhole in a well utilizing the releasing slips and a well in which a downhole tool is deployed utilizing the releasing slips of the invention is described herein. The tool has a plurality of slips for selective engagement with a wall of a wellbore. The slips include releasing slips and biting slips. The releasing slips have a low friction surface, e.g., a substantially smooth surface for engaging the wall of the wellbore. The smooth wall engaging face of the releasing slips facilitate easy release of the slips, thereby facilitating easy removal of the downhole tool. The slips may include a plurality of hardened members that protrude from the wall engaging face of the releasing slips to reduce wear on the face of the releasing slip.
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This application is a continuation-in-part of U.S. Pat. Ser. No. 387,189, filed Aug. 9, 1973, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to electronic conductor elements and more particularly to electronic brushes for use in making electrical contact between stationary and moving surfaces.
2. Description of the Prior Art
Electronic brushes are used in a wide variety of electronic devices including computers, incoders, automatic control systems, alarm systems, trimmers, precision potentiometers and the like. In all of these devices, many of which embody several individual brush components, the brush performs the important function of making reliable electrical contact between the various stationary and moving surfaces of the devices.
With the great strides made in recent years in the development of solid state devices and printed circuitry and the concomitant miniaturization of electronic devices, the design and fabrication of electronic brushes, and particularly microminiature brushes, has taken on increased significance. This is true because in many types of electronic devices it is the brush more than any other single component which governs the over-all size and functional precision of the device. Where the surface over which the brush must make electrical contact is miniaturized, the brush itself must, of course, be correspondingly miniaturized. At the same time, however, the brush must meet rigid dimensional tolerances, must be capable of making effective electrical contact with the often irregular surfaces of the circuitry with which it cooperates, and, very importantly, must be constructed so as not to damage the surfaces with which it repeatedly comes in contact during the operation of the electronic apparatus. The ideal brush capable of satisfying these diverse requirements is one that has a great multiplicity of extremely fine contact segments, or fingers, each of which is very flexible yet rugged and each of which has a smooth or coined end contact portion. Experience has shown that the greater the number of small diameter, hair-like flexible fingers in any given brush width, the greater will be the likelihood of the brush making reliable electrical contact with the mating surface and the less will the chances be of undesirable arc erosion and circuit board wear.
In the past, electronic brushes were typically fabricated from a wide variety of metal alloys using generally standard tool and die techniques. The individual brush segments were generally formed by making several biforcations or slits in sheet metal material which had been cut to the desired dimensions. Because of size and mechanical limitations in the die forming apparatus, however, the number of segments or fingers which could be formed on miniaturized brushes was severely restricted.
In an attempt to overcome the limitations inherent in standard die fabrication techniques, the so-called "wire wound" method of brush construction was recently developed. This method basically consists of closely winding an appropriate metal alloy wire having a diameter of three- or four-thousandths of an inch onto a fiberglass drum approximately six inches in diameter and then electroforming a plurality of silver bars at right angles to the wires at spaced intervals around the drum. The matrix thus formed is then cut longitudinally of the drum, removed, and flattened into a planar sheet consisting of a plurality of wires interconnected at spaced intervals by the silver bars. The planar sheet is next cut into elongated strips each having a width equal to from 10 to 25 wires. Individual brushes are then formed by cutting the wires intermediate of the connecting silver bars. Where desired, the end portions of the brushes can then be formed in a forming die into the desired cross-sectional configuration.
Although the wire wound method has been demonstrated to be superior to prior art techniques for the fabrication of small multifid electronic brushes, several serious deficiencies have been found to exist in the brushes produced by this method. For example, because of silver creepage during the plating process, silver is deposited between the strands of wire. This causes excessive spreading of the fingers when the wires are cut to form the electronic brush and may result in a failure of the brush to meet critical dimensional tolerances on brush width. If close width tolerances are not met, the brush will improperly register with the electrical circuitry with which it cooperates and performance of the device will be degraded. Additionally, the silver plating on the individual fingers causes them to be less flexible and further contributes to poor brush performance. Also because of the stress formed in the wire during the coiling operation, after the wires are cut to form the brush the individual fingers tend to curl or otherwise deform beyond acceptable dimensional tolerances.
The unique design of the apparatus of the present invention permits the automatic production of precision microminiature electronic brushes comparable in size to the brushes formed by the wire wound method, at a fraction of the cost of the wire wound brushes. With the apparatus of the present invention, brushes are produced by a fully automatic process directly from a continuous strip of the metal alloy material. The time consuming and costly electroforming step of the wire wound method is completely eliminated, as is the silver creepage problem inherent in the wire wound process.
Additionally, because in the method of the present invention the brush segments or fingers are formed while the material is securely encapsulated within the apparatus in such a manner as to prevent any lateral deformation, undesirable built-in stresses in the material are eliminated and extremely close dimensional tolerances can consistently be maintained. The time consuming and costly hand operations of stripping the silver bar wire matrix from the plating drum and cutting it to size are also eliminated thereby contributing significantly to increased production rates and over-all cost reductions.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel method and apparatus for forming a multiplicity of precisely spaced apart slits or incisions in a thin planar material.
It is another object of the invention to provide a method and apparatus for expeditiously producing from a thin planar material a component part having a body portion and a multiplicity of precisely formed equally spaced outwardly extending finger-like projections.
It is another object of the present invention to provide a novel method and apparatus for the automatic cutting and forming of a strip of thin planar material in which a multiplicity of precisely spaced apart slits or incisions can be formed longitudinally of the strip of material without the material being deformed laterally as a result of the cutting operation.
It is a further object of the present invention to provide a method and apparatus for the automatic, continuous, large scale production of multifid electronic brush contacts from a continuous strip of thin planar material.
More particularly, it is an object of the present invention to provide a novel apparatus for automatically fabricating to extremely close dimensional tolerances micro-miniature brush contacts characterized by having a multiplicity of precisely formed, outwardly extending, flexible fingers or hair-like contact elements formed into a predetermined cross-sectional configuration.
It is still another object of the invention to provide a lancing mechanism in which a strip of this planar material is encapsulated between first and second sets of oppositely disposed cutting blades which are controllably movable into an interleaving relationship in a manner so as to form a multiplicity of precisely spaced apart slits in the strip of encapsulated material.
It is another object of the invention to provide a mechanism of the type described in the preceding paragraph in which movable spacer elements are interposed between the cutting blades to prevent deformation of the cutting blades during the lancing operation.
It is still another object of the invention to provide a novel method and apparatus for the fully automatic, high volume production of precision microminiature multifid brush contacts at a very rapid rate and low unit cost.
In summary, these and other objects of the invention can be realized by an apparatus for cutting and forming a planar material including a first assembly carrying a plurality of spaced apart cutting blades; a second assembly oppositely disposed from the first assembly for carrying a plurality of spaced apart second cutting blades in planes substantially parallel to, but in a staggered relationship with, the planes of the first cutting blades; guide members for positioning the material to be cut between the cutting blades in a manner so as to prevent lateral deformation of the material during the cutting operation; and a mechanism for exerting a force to move the first and second assemblies in a direction toward one another in a manner so as to move the cutting blades carried thereby into an interleaving relationship.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the cutting and forming apparatus of the invention.
FIG. 2 is a vertical cross-sectional view taken along line 2--2 of FIG. 1 showing the apparatus significantly enlarged over FIG. 1 and partly broken away to illustrate the internal construction of the lancing subassembly of the apparatus. This view shows the material to be cut in position within the material support or guide means of the apparatus and the cutting and spacer elements or blades of the apparatus as they appear at the beginning of the cutting cycle.
FIG. 3 is a view taken along line 3--3 of FIG. 2 and is a greatly enlarged cross-sectional view of the cutting and spacer blades of the lancing subassembly showing a side view appearance of the blades and illustrating the manner in which the blades are operatively interconnected with the movable top and bottom spanner members or blade holding means of the apparatus.
FIG. 4 is a generally schematic view of the lancing subassembly of the apparatus shown at a first position with the cutting blades in first contact with the material to be cut. This view is similar to that shown in FIG. 2, but is further enlarged and shows only a limited number of blades so that the relative movement among the blade holding means, the cutting blades and the spacer blades during the cutting operation can be more easily illustrated and described.
FIG. 5 is a generally schematic view similar to FIG. 4 showing the lancing subassembly in a second position in the cutting cycle.
FIG. 6 is still a further enlargement of the encircled portion of FIG. 3 showing the working curved edge portions of the cutting and spacer blades as they appear at a first position with the cutting blade in first contact with the material to be cut.
FIG. 7 is a view similar to FIG. 6 showing the blades in a second position in the cutting cycle.
FIG. 8 is a perspective view of a portion of the multifid brush which is the end product produced by this embodiment of the invention.
FIG. 9 is a front view of the multifid brush contact illustrated in FIG. 8 showing the manner in which the lower end portions of the brush contacts or fingers are coined by the apparatus.
FIG. 10 is a generally schematic plan view of the lower half of the apparatus taken along line 10--10 of FIG. 1 illustrating the various steps of the process for making a microminiature multifid brush contact and also illustrating the configuration of the material during the various process steps.
FIG. 11 is a side elevational view of another embodiment of the invention including a novel feeding mechanism. The cutting and forming portion of the apparatus shown in FIG. 11 is identical to that shown in FIG. 1. The unique feeding mechanism of this form of the invention is shown affixed at the forward or left end of the cutting and forming portion of the apparatus.
FIG. 12 is a plan view of the feeding mechanism taken along lines 12--12 of FIG. 11 and is partly broken away to show internal construction.
FIG. 13 is a view partly in cross-section taken along lines 13--13 of FIG. 12.
FIG. 14 is a cross-sectional view taken along lines 14--14 of FIG. 12.
15 is a view similar to FIG. 14 but illustrating the appearance of the mechanism after the actuating cam members have moved to the right to bring material gripping fingers into engagement with the material to be processed in the apparatus.
FIG. 16 is a view similar to FIG. 15 but showing the appearance of the mechanism after the shuttle and cam members have been moved forwardly or to the right to advance the material a fixed distance toward the cutting and forming apparatus.
FIG. 17 is a view similar to FIG. 16 but showing the appearance of the mechanism after the actuating means have been moved to the left to permit the gripping fingers to disengage the material so that the mechanism can be returned to the position illustrated in FIG. 14.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and particularly to FIGS. 1 and 10, the various steps in the process of the manufacture of microminiature multifingered or multifid electronic brushes using the apparatus of the invention, are generally indicated by the letters A through E. At A the thin strip of raw material to be cut and formed is continuously fed into the apparatus by a feed means comprising cooperating friction rollers or a similar type of automatic feeding mechanism suitable for the purpose (not shown). The material from which the brushes are manufactured may be chosen from a wide variety of electrically conductive metals and metal alloys including nickel, beryllium-copper, phospher-bronze and gold-silver-platinum-rhodium alloys.
As indicated in FIG. 10 the strip of raw starting material 18 moves forwardly of the apparatus through a longitudinally extending guide channel until it engages stop means indicated in FIG. 10 by the numeral 20. Stop means 20 positions the strip for the first cutting operation indicated by the letter B. During this step, the material is cut along a predetermined distance to a precise width by means of a first punch and die subassembly, the details of construction of which will presently be described. The portion of the strip thus cut moves forwardly or to the right as viewed in FIGS. 1 and 10, between spaced apart first guide means generally indicated in FIG. 10 by the numeral 22. Guide means 22 serves to position the strip laterally within the apparatus and also closely engages the marginal edges of the material so as to prevent any lateral deformation of the material during the second cutting or lancing operation indicated at C. At step C, a plurality of longitudinally extending precisely spaced apart cuts are made in the strip of material.
After the material is cut at steps B and C, the strip is moved forwardly of the apparatus within guide means 22 through several idling steps as identified in FIG. 10. When the first lanced out portion of the strip reaches the cutting and forming location generally indicated in FIG. 1 by the letter D, the strip is cut transversely of the lanced out or slitted portion so as to form a multiplicity of outwardly projecting spaced apart fingers. Next, the strip is moved forwardly until the following slitted portion reaches location D. Again the strip is cut transversely of the slitted portions and simultaneously is cut at a location rearwardly of the first or preceding lanced out portion, thereby forming the discrete brush segment indicated in FIG. 10 by the numeral 26. Finally, at step E, the forward end of the brush 26 is formed in a forming die to the desired cross-sectional configuration, the ends of the fingers are coined, and the brush having a configuration illustrated in FIGS. 8 and 9 is removed from the apparatus for packaging.
In the description of the apparatus of the invention which follows, it is important for the reader to keep in mind that because of the smallness of the apparatus, a departure from scale in the drawings has been necessary to clearly illustrate the cooperative interaction of the various subassemblies and component parts of the device. By way of example, the strip of material to be cut and formed by the apparatus of the embodiment of the invention shown in the drawings is on the order of 0.100 inches wide and 0.004 inches thick. Referring to FIG. 4, the total width of the apparatus illustrated in this figure is on the order of 21/2 inches and the cutting or lancing blades generally designated by the numerals 50 and 52 are on the order of one inch long and 0.004 inches in thickness. The electronic brush formed by the particular apparatus illustrated in the drawings is on the order of 0.100 inches wide and has twenty-five outwardly protruding uniformly spaced apart fingers each approximately 0.004 inches in width.
Referring now particularly to FIGS. 1 and 4, it can be seen that the various cutting and forming subassemblies of the apparatus are typically constructed of cooperating spaced apart upper and lower die sections which are held securely in position within upper and lower die enclosures 30 and 32 by means of bolts or other suitable fasteners. The first operating subassembly, or first cutting means, for cutting the strip of raw material to a predetermined width includes a die means comprising a lower die section 34 affixed within die enclosure 32, an elongated stripper block 36 disposed adjacent the lower die section and an upper die section 38 affixed within die enclosure 30 in a spaced apart relationship with the stripper block. Operatively received within the die means are a pair of spaced apart cut off punches 40 which are adapted to move downwardly through guide channels or slots provided in the stripper block and die sections and into cutting engagement with the marginal side portions of the strip of material 18.
Provided in operative association with the die means is a first guide means shown here in the form of a longitudinally extending guide channel formed in the lower surface 42 of the stripper block. The first guide means serves to guide the strip of raw material 18 into position between the upper and lower die sections and accurately positions it within the apparatus for the shearing operation at B which is accomplished by the cut off or notching punches 40. A suitable first force exerting means, as for example a pneumatic, electric, mechanical or hydraulic powered piston assembly (not shown), is operatively coupled with the cutting punches and is adapted to controllably move the punches within the guide channels of the die sections in a direction generally normal to the plane of the strip of material with a force sufficient to cut the marginal edges of the material.
During the cutting or shearing operation at B, the strip of material is held closely encapsulated between the stripper block and the lower die section with the center portion thereof rigidly supported so that as the notch punches move downwardly within the guide channels of the die sections the marginal edge portions of the material will be cleanly and accurately sheared along a distance equal to the width of the punches 40. As shown in FIG. 1, suitable openings are provided in the lower die enclosure 32 for removal of the portions of the material which are cut away. As previously noted, after shearing step B, the strip of material, which has been cut to the exact width W (indicated in FIG. 10 by the numeral 18a), is moved within guide means 22 a distance equal to the length L of the cut made by the notching punches. This positions the material for the important lancing step of the invention.
As illustrated in FIG. 1, the lancing subassembly or second cutting means of the invention is located forwardly of the first cutting means at location C. Referring now particularly to FIGS. 1, 2 and 3, the lancing subassembly can be seen to comprise a first movable means located on the first side of the strip of material 18a and adapted to carry a plurality of spaced apart first cutting blades 50; a second movable means oppositely disposed from the first means and located on the second side of the strip of material 18a for carrying a plurality of spaced apart second cutting blades 52 disposed in planes substantially parallel to, but in a staggered relationship with, the first cutting blades; and guide means for accurately positioning the strip of material between the cutting blades. This guide means, previously identified by the numeral 22, also serves the very important function of closely engaging the lateral margins of the strip of material in a manner to prevent lateral deformation of the material during the lancing or cutting operations.
In the embodiment of the invention shown in the drawings, the first and second means for carrying the cutting blades are provided in the form of upper and lower die sections 56 and 58 respectively (FIGS. 1 aand 3). These die sections are fixedly mounted within upper and lower die enclosures 30 and 32 and include first and second spanner members 60 and 62 respectively. These spanner members, shown here as transversely extending outwardly protruding bar-like projections formed integrally with the die sections, are adapted to engage interengaging means provided on the cutting blades depicted in the drawings as notches 64 which, in this embodiment, are formed in the edge portions of each of the cutting blades. As will be discussed in greater detail in the paragraphs which follow, as die sections 56 and 58 are moved toward each other, the cutting blades carried by the spanner members will correspondingly move toward one another into an interleaving relationship as illustrated in FIG. 5.
As best seen in FIG. 2, the upper and lower sets of cutting blades are held captive within the apparatus between pairs of upper and lower die sections 66 and 68 which die sections are also fixedly secured within upper and lower die enclosures 30 and 32 by means of bolts 70. Guide means 22 are shown in this form of the invention as upwardly extending projections provided at the inner margins of die sections 68.
Also forming a part of the lancing subassembly is a plurality of first and second spacer elements or blades 72 and 74 (FIG. 2) disposed in interleaving relationship with the first and second cutting blades 50 and 52. As clearly shown in FIG. 2, first spacer blades 72 are interconnected with a transversely extending spanner member 76 provided on an upper pressure pad member 78 which in this embodiment of the invention comprises a third movable means for moving the spacer blades in a direction away from cutting blades 52 as the cutting blades are moved into an interleaving relationship with cutting blades 50.
Similarly, second spacer blades 74 are interconnected with fourth movable means, provided in the form of a lower pressure pad 80 having a transversely extending spanner member 82 for moving the spacer blades in a direction away from cutting blades 50 as the cutting blades are moved into an interleaving relationship with cutting blades 52. As will be later discussed, the spacer blades perform the important function of preventing deformation of the cutting blades during the lancing operation.
By referring to FIGS. 1 and 3, it can be seen that the spacer blades 72 and 74 are provided with means in the form of notches 84 formed in the edges of the blades for interengaging the spanner members 76 and 82. It will also be observed that the spacer blades are provided with slightly wider notches 86 located closer to their inner curved ends to accomodate free movement of spanner members 60 and 62 of the die sections 56 and 58. Similarly, as shown in FIG. 3, the cutting blades 50 and 52 are also provided with slots 88 located near their outer ends to accomodate free movement of spanner members 76 and 82 of pressure pads 78 and 80. The purpose of these last described notches will become apparent from the description which follows.
Referring again to FIGS. 1 and 2, it can be seen that the upper and lower die sections 66 and 68 are provided with a plurality of generally vertically extending bores adapted to slideably accomodate upper and lower cylindrically shaped reaction means in the form of push rods 90 and 92 each of which have enlarged head portions 90a and 92a respectively. When the apparatus is at rest, as shown in FIG. 2, the head portions of the push rods are disposed in engagement with the inner surfaces of pressure pads 78 and 80, and the opposite or inner ends of the push rods are slightly spaced apart from the inner surfaces of the upper and lower die sections 66 and 68. As will be described in more detail in the section herein entitled Operation of the Lancing Subassembly, the reaction means or push rods 90 and 92 form a part of the operating means of the invention which serves to move the pressure pads and the interconnected spacer blades outwardly in response to inward movement of the upper and lower die members of the subassembly.
As illustrated in FIG. 2, pressure pads 78 and 80 are arranged to move outwardly against the urging of biasing means which is shown in this embodiment as comprising pairs of upper and lower coil springs 94 and 96. Springs 94 and 96 are located within cylindrical bores 97 provided in the base portions of the upper and lower die enclosures 30 and 32 and are held captive between the upper and lower pressure pads 78 and 80 and the upper and lower pressure plates designated by the numerals 98 and 100. These pressure plates engage the outer surfaces of the base portions of the upper and lower die enclosures and form a part of the second force exerting means of the invention. The second force exerting means also includes a mechanical, electrical, hydraulic or pneumatic force generating mechanism (not shown) of a type well known in the art which can be operatively coupled with the pressure plates 98 and 100 in a manner so as to move the upper and lower portions of the lancing subassembly uniformly toward one another in a controlled manner.
Operation of the Lancing Subassembly
The operation of the lancing step of the invention can perhaps best be understood by referring to FIGS. 2, 4 and 5 of the drawings. In FIG. 2, the various components of the subassembly are shown as they appear with the apparatus at rest. FIG. 4, which it must be recognized is generally schematic in nature and for purposes of illustration shows only a limited number of the cutting and spacer blades, illustrates the appearance of the apparatus after the upper and lower portions of the lancing subassembly have been moved by the second force exerting means uniformly toward one another a limited distance. Because of the fact that the upper and lower cutting blades 50 and 52 are operatively interconnected with the spanner members 60 and 62 of die sections 56 and 58 respectively, blades 50 have correspondingly moved downwardly to a position of engagement with the upper surface of the strip of material 18a. Similarly, cutting blades 52 have moved upwardly a corresponding distance into engagement with the lower surface of the material. Although only three upper and two lower cutting blades are shown in FIG. 4, it is to be understood that in actual practice, as illustrated in FIG. 2, there are provided within the apparatus thirteen upper and twelve lower cutting blades each approximately 0.004 inches in thickness.
As can be seen in FIG. 4, the relative movement of the upper and lower die sections toward one another also causes the inner ends of the push rods 90 and 92 to move into engagement with die sections 68 and 66 respectively. Because the push rods are slideably movable within the die sections and have their outer ends in engagement with the pressure pads 78 and 80, the relative movement of the upper and lower die sections causes the pressure pads to move outwardly against the urging of biasing means or springs 94 and 96. This movement of the pressure pads in turn causes the upper and lower spacer blades 72 and 74, which are operatively coupled to the spanner members 76 and 82 of the pressure pads, to move outwardly relative to the cutting blades with which they are interleaved.
It is to be observed that the notches provided in the cutting blades to accomodate the spanner member of the pressure pads are of such a width as to permit the spanner member to move outwardly without interference to the simultaneous downward movement of the cutting blades. Similarly, the notches provided in the spacer blades to accomodate the spanner members of the die sections 56 and 58 are configured to permit the spanner members to move inwardly toward the strip of material to be cut without interfering with the simultaneous outward movement of the spacer blades.
Referring now to FIG. 5, the relative position of the various elements of the lancing subassembly is illustrated subsequent to continued movement of the upper and lower sections of the subassembly toward one another. At this point in the operation, the lancing of the material 18a has been accomplished and the subassembly is ready to return to its rest position preparatory to commencement of the next lancing operation. In the orientation of the lancing subassembly illustrated in FIG. 5, the upper and lower die sections 66 and 68 have moved a maximum distance and the upper surfaces of guide member 22 are in engagement with the lower surfaces of die sections 66. Upper and lower cutting blades 50 and 52 have moved into an interleaving relationship and, against the urging of springs 94 and 96, the pressure pads 78 and 80 have been moved outwardly by push rods 90 and 92. This outward movement of the pressure pads has also moved the upper and lower spacer blades 72 and 74 outwardly a distance corresponding to the inward movement of the cutting blades.
By referring concurrently to FIGS. 5, 6 and 7, the cutting or lancing action of the cutting blades and the cooperative interaction of the spacer blades can perhaps best be understood. As shown in FIGS. 6 and 7, the curved leading or cutting edge of the cutting blades, identified in these figures by the number 50, are specially ground to present a roughened, sawtooth-like effect which prevents the material being cut from slipping or tearing during the lancing operation. The curved leading edges of the spacer blades (identified as 74), however, are ground to a smooth highly polished finish. This was found necessary because the spacer blades perform the dual function of eliminating deformation of the cutting blades, and also serve to assist in ejecting metal segments or particles from between the cutting blades as the subassembly returns to its starting position. By grinding the leading edge to a smooth finish, the washing or chip ejecting action of the spacer blades is significantly improved.
As the cutting blades move inwardly into an interleaving relationship, the portion of the material in contact with the curved surface of each of the blades is deformed in the direction of movement of the blades. As shown in FIG. 7, due to the novel construction of the subassembly, as previously described, this movement of the cutting blade is closely tracked by the opposing spacer blade so that the spacing between the curved edges of the two blades remains constant. With the construction thus described, the movement of adjacent cutting blades in opposite directions relative to the completely encapsulated material will cause the material to be cleanly and precisely lanced along locations intermediate the adjacent cutting blades in a manner as to form the material (identified as 18b) into the cross-sectional configuration illustrated in FIG. 5.
As a result of the precision construction of the lancing mechanism, the cooperative interaction of the cutting and spacer blades, the novel grinding of the blades and the fact that the material is closely encapsulated during the cutting operation, twenty-five precisely spaced apart cuts can be made longitudinally of a 0.100 inch wide strip of material at 0.004 inch intervals without lateral deformation of the material and without any tearing or structural damage resulting to the finger-like segments 18b thus formed.
Referring again to FIGS. 1 and 10, subsequent to the lancing operation the strip of material is moved through several idling steps which are necessary in order to accomodate the physical size and side-by-side orientation of the various subassemblies of the apparatus. As the first slitted portion of the material reaches point D, the third cutting operation is accomplished by a third cutting means which cuts the strip of material transversely of the slitted portion so as to form a multiplicity of spaced apart finger-like projections. The strip is then moved to the position shown by the brush 26 in FIG. 10. This locates the second slitted portion 102 at position D and the third cutting step is repeated, cutting the second slitted portion transversely to form spaced apart fingers 104. Simultaneously, a fourth cut is made transversely of the solid portion 106 of the strip located rearwardly of the first or forward slitted portion. As can be seen by referring to FIG. 10, as the strip moves sequentially forward the third cut (step No. 7) forms the fingers of one brush and the fourth cut shears the solid portion of the strip located forwardly thereof so as to form a discrete brush component the fingers of which had been trimmed during the previous cycle. At the same time the fourth cut is made the finger-like projections of the brush are formed at step E into a predetermined cross-sectional configuration. The third and fourth cutting operations and the brush forming operation just described is accomplished by a cutting and forming subassembly which, as best seen in FIG. 1, comprises a lower die section 110 and a cut off and form block 112 carried by lower die enclosure 32. Comprising the upper portion of the cutting and forming subassembly is an upper die section 114 carried by upper die enclosure 30, a movable pressure means 116 located adjacent die section 114 for holdably engaging the strip of material, a cut off punch 118 movably guided within guide channels provided in die section 114 and pressure means 116, a form punch 120 movably supported by upper die enclosure 32 and third force exerting means for movably operating cut off punch 118 and form punch 120. The third force exerting means may comprise one or more well known types of mechanical, hydraulic, pneumatic or electrically powered drive mechanisms operatively associated with the cut off and forming punch.
In operation when the slitted portion of the material reaches location D, the pressure means or member 116 moves downwardly into engagement with the material so as to securely position it relative to the cut off punch 118. Next, the cut off punch 118 simultaneously cuts the material transversely of the slitted portion positioned beneath the punch and transversely of the solid portion of the strip immediately forward of the slitted portion. While the material is held in position within the subassembly, form punch 120 moves downwardly toward form block 112 so as to form the brush fingers to the contour of the form block. For certain applications it is desirable as a part of the forming operation to coin the ends of the fingers as shown in FIG. 9.
After the cutting operation has been accomplished, the section of the strip of material which has been cut out is ejected from the apparatus through a passageway 122 provided for the purpose in the lower portion of the cutting and forming subassembly. Finally, the finished multifid brush having a configuration generally as illustrated in FIG. 8 is removed from the apparatus for packaging.
In FIGS. 11-17 there is illustrated another embodiment of the invention including a unique feeding mechanism for controllably feeding the material to be processed toward the cutting and forming subassemblies of the apparatus. As will be discussed in greater detail in the paragraphs which follow, this novel feeding mechanism completely encapsulates the material during the feeding process thereby eliminating any possibility of the material buckling or otherwise deforming as it is advanced toward the cutting and forming subassemblies. Such close confining of the material during feeding is not possible with conventional feeding systems such as conventional cooperating feeding rollers and the like. Although the drawings illustrate the feeding of a very thin elongated strip of material, the feeding mechanism of the invention is equally well suited for feeding material in other configurations such as, for example, fine wire.
Turning now to FIG. 11, the feeding mechanism of this embodiment of the invention, generally identified by the numeral 130, is shown affixed to the forward or left end of stripper block 36 by means of suitable fasteners 132. Since the various cutting and forming subassemblies of this embodiment of the invention operate in an identical manner as previously described, only the construction and operation of the feeding mechanism 130 of the invention will be considered in the paragraphs which follow.
Referring particularly to FIGS. 13 and 14, the feeding mechanism includes means 134 for encapsulating and guiding the material 18 during its advancement within the apparatus. Means 134 comprises a base plate 136 and a cover plate 138 which cooperate to define a longitudinally extending passageway or slot 140 for closely receiving the material 18. In the embodiment of the invention shown in the drawings, cover plate 138 is provided with the guide slot and the base plate is formed with a planar upper surface so that when the base plate and cover plate are interconnected in the manner shown, an elongated passageway 140 generally rectangular in cross-section will be formed. Carried by the means 134 are gripping means, generally designated by the numeral 142. In this form of the invention, the gripping means comprise first and second oppositely disposed material gripping fingers 144 and 146 respectively, each having material gripping inner extremities 145 receivable within elongated slots 147 formed in the base plate 136 and the cover plate 138 (FIG. 12). These gripping fingers are reciprocally movable relative to material 18 within bores 148 formed in first and second shuttle members 140 and 152, which members also form a part of the gripping means of the invention. As illustrated in FIGS. 14-17, shuttle members 150 and 152 are longitudinally slidable within guideways 154 defined by shoulders 155 formed in the base plate 136 and in the cover plate 138, and by guide plates 156 affixed to the base plate and cover plate by appropriate fasteners 157 (FIG. 13). Also forming a part of the gripping means of the invention are cam means generally designated as 158 (FIG. 14) for imparting reciprocal movement to said gripping fingers to move the inner extremities 145 thereof into close proximity and into gripping engagement with the material 18.
Cam means 158 comprises identically configured first and second cam members 159 and 160 respectively, each having a tapered gripping finger engaging cam face 162 forward on the upper right side thereof as viewed in FIG. 14. Each cam member is also provided with a cam driver pin 164 and a cam return pin 166 (FIG. 14), the purpose of which will presently be described. As best seen in FIG. 14, cam members 159 and 160 are longitudinally slidably carried by shuttles 150 and 152 respectively, with cam return pins 166 longitudinally movable a limited distance within slots 168 formed in shuttles 150 and 152.
Cooperatively associated with the gripping means of the invention are actuating means for operating the cam means and for moving the entire gripping means in a first or feeding direction when the fingers of the gripping means are in gripping engagement with the material and in the opposite direction when the fingers are in a released or outward position. Turning to FIGS. 11 and 12, the actuating means of this form of the invention can be seen to comprise a yoke-like activating lever 170 having spaced apart arms 171 which are pivotally interconnected near their extremities by suitable fasteners 172 to the base plate 136 and the cover plate 138. Intermediate the spaced apart arms of the yoke portion of the actuating lever are elongated slots 174 adapted to cooperatively receive cam driver pins 164 of the cam members 158 and 160.
Operation of Feeding Mechanism
Operation of the feeding mechanism of this embodiment of the invention can best be understood by referring to FIGS. 14-17. FIG. 14 shows the feeding mechanism in an at-rest starting position. Movement of actuating lever 170 to the right from the position shown in the solid lines in FIG. 12 toward the position shown in the phantom lines will, due to the urging of the yoke arms on the cam driver pins, cause cams 158 and 160 to move into the position shown in FIG. 15. During this movement the tapered cam faces 162 will cause movement of gripping fingers 144 and 146 toward each other within bores 148 formed in shuttles 150 and 152 against the urging of a biasing means. In this form of the invention, the biasing means is provided in the form of coil springs 176 surrounding fingers 144 and 146 and interposed between head portions 149 formed on the fingers and shuttles 150 and 152. This movement will continue until extremities 145 of the gripping fingers move into secure gripping engagement with the opposite surfaces of material 18.
An important feature of the invention is the provision of novel locking means adapted to resist sliding movement of shuttle members 150 and 152 until the gripping fingers are in secure engagement with the material. Referring to FIG. 13, the locking means of this embodiment of the invention can be seen to comprise first and second detent assemblies 178 and 180 carried by base plate 136 and cover plate 138 respectively. Each detent mechanism is of identical construction and comprises a threaded member 182 threadably received in the base plate and cover plate, a ball bearing 184, and a biasing means in the form of a coil spring 186 interposed between the ball bearing and the threaded member. As best seen in FIGS. 13 and 14, each of the shuttle members 150 and 152 is provided with forward and rear depressions 188a and 188b adapted to engage a portion of ball bearings 184. With this construction, coil springs 186 will continually urge ball bearings 184 toward the shuttles and at a particular point of the advance and return cycles into depressions 188 so as to releasably lock shuttles 150 and 152 against sliding movement. For example, with the mechanism in the position shown in FIG. 15, ball bearings 184 are releasably held in the forward depressions indicated by the numeral 188a and the detent mechanism will yieldably resist sliding movement of the shuttles. Continued pressure on actuating lever 170, however, will cause the gripping fingers to grip the material with sufficient force to overcome the resistance offered by the locking means against movement of the shuttles permitting them to be moved to the right into the position illustrated in FIG. 16. In this position, it is to be noted that the ball bearings 184 of the locking means have now moved into engagement with the rear depressions designated 188b in FIG. 16. It is also to be noted that this movement of shuttles 150 and 152 has resulted in concomitant movement to the right of gripping fingers 144 and 146 and in the advance of material 18 toward the cutting and forming apparatus. As illustrated in FIG. 16, the degree of longitudinal movement of shuttles 150 and 152 and the simultaneous advance of the material, is limited by shoulders 190 and 192 formed in base plate 136 and cover plate 138 respectively.
During the return cycle, movement of actuating lever 170 to the left will, in cooperation with driver pins 164, cause cams 158 and 160 to move into the position shown in FIG. 17. This movement of the cams will permit coil springs 176 to urge gripping fingers 144 and 146 outwardly or away from each other into a released position and out of engagement with the material 18. As illustrated in FIG. 17, this leftward movement of the cams has also moved cam return pins 166 into engagement with shoulders 194 formed on shuttles 150 and 152. In this position, continued movement of lever 170 to the left, however, will be resisted by the locking means, the ball bearings of which are now in depressions 188b in the shuttle members. Only when the exertion of forces on actuating lever 170 is sufficient to overcome the resistance offered by the locking means can longitudinal sliding movement of shuttles 150 and 152 occur. In this way, complete disengagement of the gripping fingers from the material is insured prior to returning the shuttles to the starting position illustrated in FIG. 14.
In summary, the locking means of the invention thus described insures that pivotal movement of the actuating lever will result first in forward movement of cams 159 and 160 so as to move the gripping members toward each other bringing their extremities 145 into firm engagement with the material being processed. After engagement is realized, continued forces exerted on the actuating lever will increase the forces exerted by the cams on the gripping fingers and at the same time impart forces tending to shift the cams and the shuttles forwardly. When these forces become large enough to overcome the resistance offered by the detents, the assemblies will move to the position shown in FIG. 16, thus advancing the material 18 toward the cutting and forming subassemblies. Conversely, on the return cycle the locking means releasably locks the shuttles against longitudinal movement until the cams have been moved to the left and the gripping members completely moved out of engagement with the material. It is important to note that in this regard the cam return pins 166 function only to engage shoulders 194 formed on the shuttles to effect the release of the locking means on the reverse cycle of the mechanism. As shown in FIG. 15, because of the configuration of slots 168 in the shuttles, these pins play no part in moving the shuttles forwardly or to the right. Only the pressure of the cams on the gripping fingers and the resulting pressure of the fingers on the material enables movement of the shuttles against the resistance of the locking means.
Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.
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A method and apparatus for cutting and forming planar strip material which is particularly useful in the fully automatic, high volume production of precision, microminiature multifid electronic brushes. With the apparatus of the invention, high quality electronic brushes are produced automatically from a continuous thin strip of metal or metal alloy. At predetermined locations along the length of the strip, the material is cut so as to form a multiplicity of precisely spaced apart longitudinally extending slits or incisions. The material is then automatically cut transversely of the slits so as to form a multiplicity of precisely spaced apart outwardly extending fingers. The fingers are then formed in a forming die to the cross-sectional configuration desired for end product use.
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This is a continuation application Ser. No. 07/959,881 filed Oct. 13, 1992 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the plating of aluminum and aluminum alloys, and, more particularly, to the plating of 390 aluminum alloys with iron.
2. Description of Related Art
In the use of aluminum internal combustion engines with aluminum pistons for vehicles, it is essential that either the piston or the cylinder bore be coated with another metal harder than aluminum to prevent piston skirt scuffing during cold starts. Commonly, an iron coating is plated onto the surface of the aluminum pistons, generally employing a copper undercoat.
In one process, copper cyanide and iron chloride baths are used in the plating. Copper cyanide is a highly toxic and tightly regulated material. The iron chloride bath is also a highly toxic and extremely corrosive bath that is very destructive to the equipment around it.
An alternative approach is to insert an iron sleeve into the cylinder bore. Still another approach is to coat the inside of the bore with a suitable metal alloy by thermal spray coating processes and then re-machining the bore. These approaches are estimated to be 8 to 14 times as expensive as piston plating.
It is desired to provide a method, preferably inexpensive, for plating aluminum pistons with an acceptable iron coating that will pass all the required adhesion, hardness, and abrasion tests without using highly toxic or hazardous substances.
SUMMARY OF THE INVENTION
In accordance with the invention, a substitute for cyanide is provided, namely, electroless nickel. The process for plating 390 aluminum alloy substrates with iron comprises:
(a) plating on the aluminum substrate a layer of zincate from a zincate bath;
(b) plating on the zincate layer a layer of nickel from an electroless nickel bath;
(c) plating on the nickel layer a layer of iron from an iron sulfate bath; and
(d) plating on the iron layer a layer of tin from an alkaline tin bath.
All of these baths are environmentally much safer than copper cyanide and ferric chloride. They are also cost effective and can be utilized in a totally closed loop plating system.
The resulting iron-plated aluminum alloy parts comprise a first layer of nickel on a surface of the part, a second layer of iron on the first layer of nickel and a third layer of tin on the second layer of iron. The coating evidences good adhesion and wear properties.
BRIEF DESCRIPTION OF THE DRAWINGS
The sole FIGURE is a schematic drawing of the structure of an aluminum piston coated in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the process of the invention, the aluminum alloy pistons are first cleaned to remove grease and oils, typically employing a non-etching, hot alkaline cleaner. Examples of such cleaners include commercially available products, such as dishwashing compositions, CHEMIZID 740, an aqueous solution of sodium hydroxide and sodium lauryl sylfate available from Allied-Kelite, and ALKANOX, an acid-based cleaner having a proprietary composition available from VWR Scientific. The immersion time typically ranges from about 15 seconds to 1 minute. If the part is very oily or greasy, a solvent degrease step may be inserted prior to the alkaline cleaning step.
The cleaned parts are then rinsed in cold running water, acid-etched for 10 seconds to remove aluminum oxides, and rinsed again with cold water. A well-known acid etch suitably employed in the practice of the invention for removing aluminum oxides comprises about 50% water, 25% sulfuric acid, 24% nitric acid, and 1% hydrofluoric acid. However, any of the acid etches known for removing aluminum oxides may be employed, such as a solution of ammonium bi-fluoride double salt, commercially available as ARP 28 from Allied Kelite.
The parts are now ready for plating. In the first plating step, the parts are immersed in a zincate bath, such as a proprietary immersion zincate solution comprising an aqueous solution of zinc oxide and sodium hydroxide available from Allied Kelite under the tradename ARP 302 Zincate. The bath is made up according to the manufacturer's directions and is operated at room temperature. Immersion time is typically 30 seconds.
The zincate layer is essentially transitory, and is used to prevent aluminum oxides from reforming after the acid etch step. This layer is lost during the subsequent electroless nickel plating, described in greater detail below.
The zincate-coated parts are rinsed with cold running water and then immersed in an electroless nickel bath, such as a proprietary electroless nickel solution comprising an aqueous solution of nickel sulfate, sodium hypophosphate, and additional proprietary salts available from Allied Kelite under the tradename Electroless Nickel 794. Any of the known electroless nickel solutions may be employed in the practice of the invention. The bath is made up according to the manufacturer's directions and is heated to 185° to 200° F. (85° to 93.3° C.), and preferably about 190° F. (87.8° C.). Immersion time is typically about 5 minutes and results in a thickness of about 0.00005 inch (0.00013 cm). An immersion time of about 1 minute results in a thickness of about 0.000003 inch (0.0000076 cm), which is also useful in the practice of the invention.
The thickness of the nickel coating may range from about 0.000002 to 0.0015 inch (0.000005 to 0.0038 cm) to provide a layer to which the subsequently-plated iron layer will adhere. A nickel thickness less than about 0.000002 inch may not provide sufficient adherence of the iron layer thereto, and a nickel thickness greater than about 0.0015 inch may be too brittle.
The nickel-plated parts are rinsed with cold running water and are next immersed in a novel iron plating bath, the composition of which comprises an aqueous solution of ferrous ammonium sulfate. The concentration of this plating bath ranges from a value of about 250 g/L to 400 g/L. Preferably, the concentration of ferrous ammonium sulfate is about 250 g/L.
The iron plating bath may also include appropriate addition agents, such as wetters, brighteners, and the like, to enhance the plating characteristics. A brightener permits use of higher current densities, which make it possible to plate the part faster. The composition and concentration of such addition agents are well-known in the art and hence do not form a part of this invention.
The anodes are cold rolled or electrolytic iron. A current of about 10 to 75 amps/ft 2 (107.6 to 807.3 amps/m 2 ) is impressed on the part, as cathode. Preferably, the current is about 40 to 50 amps/ft 2 (430.6 to 538.2 amps/m 2 ), which provides the best combination of fast plating time consistent with good visual appearance of the iron plate.
The iron is plated to a thickness of about 0.0002 to 0.0015 inch (0.00051 to 0.0038 cm). A thickness of less than about 0.0002 inch does not provide a sufficiently thick coating of iron for wear, while a thickness of greater than about 0.0015 inch results in an iron layer that is too brittle. The preferred thickness for aluminum alloy pistons is about 0.001 inch (0.0025 cm) of iron per side.
A typical dwell time of about 20 minutes at 40 amps/ft 2 (430.6 amps/m 2 ) is used to obtain the desired thickness, although shorter or longer times at lower or higher currents may be employed in the practice of the invention to obtain the desired thickness.
The iron-plated part is rinsed in cold running water and is finally immersed in a tin plating bath, such as a proprietary alkaline non-brightened tin bath available from M&T Harshaw under the tradename AT 221-B, to form a tin “strike”. The tin strike protects the underlying iron layer against rusting.
Tin is plated on to a thickness of about 0.000005 to 0.0001 inch (0.000012 to 0.00025 cm) following the manufacturer's directions. Preferably, a “strike”, ranging in thickness from about 0.000007 to 0.000015 inch (0.0000178 to 0.000038 cm) is employed.
The bath is operated at 20 amps/ft 2 (215.3 amps/m 2 ). A typical dwell time for the “strike” thickness is about 30 seconds.
The tin-plated part is rinsed in cold running water and, after drying, is ready for assembly into the aluminum engine.
The sole FIGURE is a schematic diagram of an iron-coated aluminum alloy piston 10 , comprising a 390 aluminum piston casting 12 onto which electroless-plated nickel layer 14 , e.g., about 1 μm in thickness, is formed. An iron layer 16 , e.g., about 25 μm in thickness, is plated on the nickel layer 14 , and a tin “strike” 18 , about 0.5 μm in thickness, is plated on the iron layer 16 .
While the invention has been described in terms of plating 390 aluminum alloy pistons, which is a silicon-aluminum alloy containing about 18% silicon, the teachings of the present invention are equally applicable to the iron plating of other aluminum alloys and of other aluminum alloy parts.
Often, a bake step is employed following electroplating of, for example, iron onto an aluminum alloy. Such a baking step is intended to remove hydrogen embrittlement and to improve adhesion of the plated coating. The bake step is typically carried out at an elevated temperature, such as about 350° to 400° F., typically about 375° F., for a period of time, such as about 1 to 3 hours, typically about 1 hour. While other aluminum alloys, such as 6061, may require baking following plating, 390 aluminum alloy does not appear to require such treatment.
It is very important for many applications, such as iron plating of aluminum alloy pistons, that the iron coating have an acceptable hardness. For pistons, this hardness should be equivalent to a Rockwell hardness of about 40 or higher on the C scale. The practice of this invention provides iron coatings of acceptable hardness for such applications.
390 aluminum alloy pistons plated as above have been tested for adhesion, morphology, hardness, and thickness and have passed all tests. Adhesion tests have been run on test coupons. All coupons passed the tape adhesion test. Microscopic examination of cross-sections have shown the morphology of the deposit to be tight and close-grained. The coupons also showed good adhesion in simple abrasion tests.
EXAMPLE
Aluminum alloy coupons were cleaned, prepared with a zincate immersion, and then electroless plated with nickel, employing conventional process parameters.
A series of ferrous ammonium sulfate plating baths were formulated using various concentrations of Fe(NH 4 ) 2 —(SO 4 ) 2 .6H 2 O as shown in the Table below. Each bath had a 0.1% concentration of Wetter 22 , a proprietary surfactant wetter from Udylite. Sodium chloride was added to some, but not all, of the baths as indicated in the Table, and the pH was recorded as also shown in the Table. Coupons of 6061 aluminum and/or 390 aluminum alloy were electroplated at 40 amps/ft 2 (430.6 amps/m 2 ) for 20 minutes using an electrolytic iron anode with a 2:1 ratio of anode area to cathode area. The plating bath temperatures are also shown in the Table. The thickness of the coatings was measured with a micrometer, and then nickel or tin was plated on top of the iron coating to prevent corrosion. The coupons were micro-sectioned, the thicknesses were verified with a scanning electron microscope, and the hardness of the iron layer was determined with a Knoop microhardness indenter with a 10 g load. The results are indicated in the Table. The hardness of the iron coatings was appropriate for plated piston applications when the concentration of Fe(NH 4 ) 2 (SO 4 ) 2 .6H 2 O was between 250 and 400 g/L and the pH was about 2.7 to 2.9.
Thus, there has been disclosed iron-plated aluminum alloy parts and a process for plating the same. It will be appreciated by those skilled in the art that various changes and modifications of an obvious nature may be made, and all such changes and modifications are considered to fall within the scope of the invention, as defined by the appended claims.
TABLE
Iron Plating Parameters and Results.
NaCl
Bath
Rockwell
Ferrous Salt
Conc'n,
Bath
Temp.,
Thickness,
Hardness,
Conc'n, g/L
g/L
pH
° C.
inches
C Scale
500
0
3.5
49
0.0005
21
450
0
3.2
49
0.0006
25
400
0
3.0
49
0.0008
37
350
0
2.9
49
0.0006
36
350
50
2.8
49
0.0008
37
300
50
2.7
49
0.0010
41
250
50
2.7
49
0.0010
37
250
50
2.7
29
0.0012
47
200
0
2.4
49
0.0004
27
150
0
2.0
49
0.0002
19
100
0
1.7
49
no deposit
—
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A process for plating aluminum alloy substrates ( 10 ), such as 390 aluminum alloy pistons ( 12 ), with iron comprises (a) plating on the aluminum substrate a layer of zincate from a zincate bath; (b) plating on the zincate layer a layer ( 14 ) of nickel from an electroless nickel bath; (c) plating on the nickel layer a layer ( 16 ) of iron from an iron ammonium sulfate bath; and (d) plating on the iron layer a layer ( 18 ) of tin from an alkaline tin bath. During the electroless plating, the zincate layer, which protects the underlying aluminum against oxidation, is sacrificed. All of these baths are environmentally much safer than cyanide and chloride. They are also cost effective and can be utilized in a totally closed loop plating system.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a division of U.S. application Ser. No. 10/521,160, which is the national stage of PCT/CH2003/000415, filed Jun. 25, 2003, which claims priority to CH 1150/02, filed on Jul. 2, 2002, all of which are herein incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method of manufacturing shaped and reinforced fabrics, and more particularly to a method of manufacturing shaped and reinforced fabrics continuously in alternation, the fabric being constituted by composite elements which are constituted by a membrane, impervious for example, which encases reinforcing elements, threads for example, the elements constituting the fabric being capable of being shaped in three dimensions so that the fabric has a desired shape in three dimensions.
[0003] Reinforced and shaped fabrics are used in all cases where a fabric has to be reinforced generally and in particular when a fabric has to be reinforced in particular directions which are determined by the forces that act on the fabric. By way of example, when a fabric acted on greatly by forces comprises fixing eyelets at the location of its corners or elsewhere, reinforcements may be necessary to distribute the forces, maintain the shape and avoid tears. Moreover, if large forces act between one or other of the eyelets, reinforcements may be necessary in the direction of the forces.
[0004] In many cases, it is necessary for the fabric to have particular shapes in three dimensions whether for reasons of performance or for aesthetic reasons.
[0005] The manufacture of high-performance reinforced and shaped fabrics is subject to several parameters including of course commercial criteria which require that a fabric must be high-performance, as light as possible and of course with a price as low as possible.
[0006] Many embodiments of reinforced and shaped fabrics and of reinforced and shaped fabric manufacture are known but they all have many drawbacks.
[0007] A basic drawback of all the known high-performance reinforced and shaped fabrics is that the structure of the fabric is constituted by an assembly of elements of the sandwich type, that is to say the fabric consists of at least three components, these being the reinforcing elements which are assembled by bonding in a sandwich between two polymerised plastic sheets, for example. This type of fabric construction is expensive and has a fairly heavy weight. The polymerised plastic sheets are semi-rigid and may not allow local deformations. The overall shape of the fabric must allow a desired shape to be obtained over the whole dimension of the fabric which consequently requires moulds with the total size of the sail which are very expensive. These manufacturing methods with total-size moulds have several drawbacks, one of the greatest of which is the cost which is inevitably carried over to the end product. Another drawback is the space requirement of these moulds which require very large production premises. Moreover, the large cost of the tools implies a lack of flexibility when changes in shape are necessary which slows down the development phases and makes them very expensive. As the reinforcing threads are generally each placed in one piece with these embodiments, the positioning is very tricky.
[0008] Other known embodiments are implemented by assembling several fabric panels from different cuts, the panels being assembled together by sewing or bonding. The location of the sewing is fragile and requires reinforcing panels themselves added on by sewing. The forces to which the fabric is subjected are therefore dependent on the strength of the sewing at these locations which, as said, has the drawback of requiring reinforcing panels which contribute towards increasing the overall weight of the fabric. Moreover, at the locations of the sewing and the reinforcing panels, the fabric is less flexible than the other panels of the fabric, which causes many creases and fatigue of the materials when the fabric takes the desired shape, which is unsightly and can reduce the performance of the fabric for certain forms of use.
SUMMARY OF THE INVENTION
[0009] The aims of the present invention therefore consist of remedying the aforementioned drawbacks of the known embodiments.
[0010] The aims are achieved according to the principles of the invention as described in claim 1 .
[0011] The method of manufacturing shaped and reinforced fabrics according to the principles of the invention consists of carrying out the manufacture of the fabric continuously. A press of small width compared with the length of the fabric successively presses the constituent elements of the fabric. Reinforcing elements, threads for example, are prepared on a belt which is disposed able to move on a preparation table and discontinuous reinforcing elements are disposed overlapping the waiting part of the fabric already pressed. The reinforcing elements can thus be disposed in all directions according to the direction and magnitude of the forces to which the fabric is subjected. The upper and lower chambers of the press comprise movable and adjustable devices which make it possible to obtain, during pressing, a desired shape in three dimensions at desired locations. By successive forward movements of the fabric and depending on the adjustments, the fabric can have flat portions or have portions in three dimensions, and the shape of the portions in three dimensions can be varied quickly according to the final shape provided for the fabric. The elements that constitute the fabric consist of threads which are encased by a membrane which is constituted by resin. Before pressing, these elements are in the form of strips which can be constituted by a prepreg of resin and threads, the preimpregnation having the advantage of holding the threads. Once pressed, the fabric is constituted by the membrane which is the resin which encases the threads or rather the filaments of the threads. In fact the threads are constituted by thousands of filaments which are distributed over the width of each strip. During preparation, part of each strip is placed on the juxtaposed strips and during pressing the filaments of the different strips intermix so as to constitute a homogeneous and impervious fabric for example.
[0012] The principles of the invention have many advantages. One of the major advantages is that the fabric once completed is constituted, in section, by two elements, these being the membrane and the reinforcing filaments, and consequently the manufacturing method allows the elements to be reduced in comparison with the known three-layer embodiments. This reduction in the number of elements makes it possible to obtain a reduction in the weight and cost.
[0013] The fact that the completed fabric is in the form of a membrane encasing thousands of intermixed filaments makes it possible to obtain a highly homogeneous sail, with no creases and with reinforcements which make it possible to withstand all the forces to which the fabric can be subjected. The membrane and the filaments also have the advantage of being practically indeformable in the direction of the forces whilst being highly flexible during folding of the fabric for example.
[0014] The press has a very small space requirement compared with the dimensions of fabrics to be manufactured which makes it possible to install it in premises of small dimensions.
[0015] The shaping device integrated with the press which makes it possible to obtain portions of fabric in three dimensions, which makes it possible to obtain a finished fabric in three dimensions, has many advantages. One of these advantages is that the shaping device makes it possible to eliminate the expensive tools such as the three-dimensional moulds or tools. This is because the shaping device can allow a multitude of different shapes to be obtained by simple and very quick adjustments. This advantage is very important during manufacture but is also very important during the development of new fabrics having new shapes, the adjustment device making it possible to obtain a new shape very quickly by simple and quick adjustments.
[0016] The principles of the invention make it possible to considerably reduce the manufacturing costs whilst making it possible to obtain higher performance fabrics.
[0017] The accompanying figures illustrate schematically and by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an overall side view of the press and the various elements attached to the press.
[0019] FIG. 2 is a front view of the press with the shaping device.
[0020] FIG. 3 is an overall side view of the press with the shaping device in the shaping position.
[0021] FIG. 4 is a front view of the press with the shaping device in the shaping position.
[0022] FIG. 5 is a view of the press with an infrared heating device.
[0023] FIG. 6 is a sectional view of a membrane encasing threads disposed unidirectionally.
[0024] FIG. 7 is a sectional view of a membrane encasing threads disposed multidirectionally.
[0025] FIG. 8 is a plan view of strips before pressing.
[0026] FIG. 9 is a plan view of a fabric with strips disposed in different directions.
[0027] FIG. 10 is a sectional view of portions of fabric shaped in three dimensions.
[0028] FIG. 11 is a sectional side view of a spread-out fabric.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] With reference first of all to FIG. 1 , a press is constituted by an upper chamber 1 and a lower chamber 14 . The lower chamber 14 comprises L-shaped angle irons 15 and 16 . The upper part of the lower chamber 14 comprises a flexible element 17 (a silicone membrane for example) which is mounted hermetically on the lower chamber 14 . The lower chamber 14 is filled with water 18 which is brought via a water inlet 24 . The water inlet is controlled by a valve 35 . The lower chamber comprises a water outlet 19 which is a balancing outlet. The water outlet 19 is connected by a duct to a tank 20 which contains water 21 . The tank comprises a water overflow 23 which determines the height of the water level 22 . The height of the water level 22 is provided to be at the level of the lower face of the flexible element 17 . The water level in the lower chamber is thus controlled by the communicating vessels principle. A valve 58 is mounted between the water outlet 19 and the tank 20 . Closing of the valve 58 makes it possible to block off the water circulation and annul the communicating vessels principle. A balancing tank 59 is placed under the overflow 23 . When water overflows via the overflow 23 into the balancing tank 59 , the surplus water in the balancing tank is constantly taken back into the tank 20 via a duct 61 which is connected to a pump 60 . The upper chamber 1 is closed off in its lower part by a flexible element 4 which is mounted hermetically with the upper chamber. The upper chamber contains air 5 which is brought via an air inlet 6 . The pressure of the air is controlled by a manometer 11 . The upper chamber 1 comprises reinforcing elements 2 . A metal girder 3 is mounted on the reinforcing elements, the whole being assembled by welding for example. The metal girder 3 is connected to an actuator or to any mechanical device whatsoever making it possible on the one hand to lift up the chamber during the preparation operations or to apply a pressure downwards during the pressing operation. A threaded rod 7 which comprises an activation nut 8 cooperates with a tapped element 9 which is mounted on the upper chamber. The lower end of the rod is connected with play to a shaping bar 10 . A preparation table 25 is mounted on feet 26 and a receiving table 27 is mounted on feet 28 . A conveyor belt 29 is mounted able to move on the tables and on the flexible element 17 of the lower chamber 14 . The conveyor belt is supported by two fixed rollers 30 and 31 and by a movable roller 32 which is subject to the action of a draw spring 33 which adjusts the tension of the conveyor belt 29 according to the deformations thereof. The reinforced strips 34 which constitute the fabric once the pressings have been performed are prepared on the conveyor belt, and then pass under the press and come out in the form of a fabric constituted by a membrane which encases filaments.
[0030] FIG. 2 shows in a front view the threaded rods 36 , 37 , 7 , 38 , 39 , which are connected in their lower part to the shaping bar 10 . The shaping bar is not fixed to the rods in its longitudinal direction, but is mounted able to move so that when the shaping bar is deformed the tensions on it can be absorbed. FIG. 2 shows the metal girder 3 , the upper chamber 1 in which the shaping bar is installed and the reinforcing elements 2 of the upper chamber, the flexible elements 4 and 17 , the water inlet 24 , the balancing water outlet 19 , the air inlet 6 , the lower chamber 14 , the conveyor belt 29 and the roller 30 and the reinforced strips 34 .
[0031] The position shown in FIGS. 1 and 2 is the flat pressing position in which the shaping bar is in the inactive position. In this position, the water in the lower chamber is kept at its level by the communicating vessels principle and then the valve 58 is closed, and the air contained in the upper chamber is put under pressure, at a pressure value which is determined by the kind of resin of the reinforced strips.
[0032] During the pressing, the resin must be heated to or activated at a temperature determined by the kind of resin. Several heating possibilities can be provided according to FIG. 1 . One possibility is heating of the air contained in the upper chamber. One possibility is heating of the water contained in the lower chamber. One possibility is heating of the preparation table just before the reinforced strips are moved under the press.
[0033] For the case where the heating is not obtained by the preparation table, this table is in any case heated to a certain temperature necessary for a slight adhesion of the reinforced strips in order to facilitate the putting down of these strips.
[0034] FIG. 1 shows an immobilising element 12 which is activated by an immobilising actuator 13 . In the position of movement of the conveyor belt, the immobilising element is inactive.
[0035] In practice, the first reinforced strips are disposed on the preparation table. Once the reinforced strips have been put down, the conveyor belt places these first reinforced strips under the press, the upper chamber is moved towards the base until contact with pressure is made on the lower chamber, by heating and the air pressure in the upper chamber the reinforced strips are converted into a membrane encasing filaments, the whole constituting an impervious or pervious fabric. One or both chambers are cooled, thus cooling the membrane. Movement of the reinforced strips by the conveyor belt leaves a portion of the strips on the preparation table for connection with the second series of reinforced strips. During the time of pressing the first reinforced strips, the second strips are disposed on the preparation table and when the operation of pressing the first reinforced strips is accomplished, the air pressure is reset to ambient pressure, the upper chamber is lifted up and the second reinforced strips are placed under the press. The manufacturing time for a fabric is determined by the time necessary for heating of the reinforced strips and cooling. By way of example, according to the resins used, the pressing time can be limited to a few minutes which are necessary in any case for disposition of the next reinforcing strips.
[0036] FIGS. 3 and 4 show the pressing of a portion of reinforced strips with shaping in three dimensions. In this case, when the reinforced strips 34 are installed under the press, the rods 36 , 37 , 7 , 38 , 39 , are activated, for example by means of nuts such as the nut 8 so as to give an arc shape to the bar 10 . The immobilising element 12 is activated by the immobilising actuator 13 and immobilises the portion of fabric already completed. In this way, the threads of the reinforced strips can take the shape provided for, and therefore the resulting difference in length of the third dimension. During the pressing with shaping, the flexible elements 4 and 17 and the conveyor belt 29 also take the chosen shape. The movable roller 32 moves upwards while maintaining the tension in the conveyor belt by the spring 33 . The shaping position, and therefore the movement of the shaping bar 10 downwards, reduces the volume of the lower chamber 14 and the excess water 18 can leave via the water outlet which goes into the tank 20 and overflows via the overflow 23 . The valve 58 is closed immobilising the quantity of water in the chamber 14 , and the air 5 is put under pressure.
[0037] When the pressing is complete, the shaping bar is replaced into the inactive position, the valve 58 is opened, the water is put back to its level by the pump 60 which takes the excess water contained in the balancing tank 59 back into the tank 20 via the duct 61 . The other pressing operations are identical to the flat pressing operations.
[0038] In practice and with the aim of obtaining the desired finished fabric shape in three dimensions, some portions of the fabric are pressed flat, and others with various shapes of the shaping bar.
[0039] FIG. 5 shows another heating possibility with infrared heating elements 40 and 41 which are disposed in the upper chamber.
[0040] FIG. 6 shows a portion of fabric with the membrane 42 which encases the threads 43 disposed unidirectionally. In practice and after pressing, the threads are in fact constituted by thousands of filaments.
[0041] FIG. 7 shows a portion of fabric with the membrane 46 encasing warp threads 44 and weft threads 45 multidirectionally.
[0042] FIG. 8 shows in plan view the reinforced strips 34 which are disposed on the conveyor belt 29 which is placed on the preparation table with passage under the press depicted in this figure by the upper chamber 1 . FIG. 8 shows different sorts of unidirectional 47 or bidirectional 48 reinforced strips which can be used by way of example.
[0043] FIG. 9 is a plan view of a fabric which shows a few example possibilities of disposition of reinforced strips, that is the reinforced strips 49 , 50 , 51 , 52 , which make it possible to obtain strength in an arc, the strip 53 which has a reinforcement at 90°, or strips 55 and 54 which can be disposed at the location of an eyelet 56 for example.
[0044] FIG. 10 shows a sectional view of a fabric with portions deformed in three dimensions according to FIG. 4 in the non-taut position.
[0045] FIG. 11 shows the three-dimensional shape taken by the fabric when it is taut.
[0046] The various activation elements, the threaded rods, the movements of the upper chamber, the forward movement of the conveyor belt, the immobilising element, opening and closing of the water supplies and outlets, switching on and off of the heating, and the air pressure, can be obtained by electric motors, step-by-step motors for example, actuators, valves or electrical controls. Each of these elements can be connected to a computer whose program manages the activation. It is also possible to dispose the reinforced strips by a transport and placing device which can also be managed by the computer program.
[0047] In this way, the manufacture of the fabric can be fully automatic.
[0048] There are numerous uses for fabrics in three dimensions, and these fabrics can be used in all cases requiring light, very strong and three-dimensional fabrics.
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The invention relates to a method of producing reinforced, formed fabrics, consisting in producing a continuous fabric alternated with a membrane ( 34 ) containing embedded reinforcing elements, which is prepared in overlapping portions on a conveyor belt ( 29 ) which passes over a preparation table ( 25 ). The membrane ( 34 ) and the reinforcing elements are then positioned under a press consisting of an upper air-filled chamber ( 1 ), the lower part thereof comprising a flexible element ( 4 ), and a lower water-filled chamber ( 14 ), the upper part thereof comprising a flexible element ( 17 ). According to the invention, a forming bar ( 10 ) is adjustably mounted in the upper chamber ( 1 ). When the aforementioned forming bar ( 10 ) is adjusted to adopt a particular shape, the different flexible elements can deform at the forming bar and the membrane and the reinforcing elements are hot pressed with a portion corresponding to the forming bar having a three dimensional shape, thereby defining the form of the fabric produced.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pad with shape adapting properties, and preferably a moisture or liquid absorbing pad.
2. Description of the Prior Art
There is a need for pads with shape adapting properties in various fields of use, e.g. breast shields, made from an absorbing material. Most pads which are currently available have been shaped into desired configuration when manufactured. The shape established when manufactured can thus not be changed by the user, and as a result, the shape can not be adapted to the requirements of each individual user. Furthermore such pre-shaped pads are also difficult to provide in pocket-size packages due to the manufactured configuration, and are also difficult to dispense from table or wall dispensers.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a pad with shape adapting properties, which prior to use extends in one plane only, and which does not exert pressure on a protruding object protected by the pad, and also protects said object from touching or contacting other objects applied in direction towards the pad. These features have been unobtainable with previously known techniques, and it is now possible to supply plane pads with shape adapting properties, which efficiently protect and adapt to the configuration of the object to be protected, and such an individual adaption has been impossible to achieve with pre-shaped pads.
The pad with shape adapting properties according to the present invention is mainly characterised in that it includes at least two adjacently located layers of a preferably absorbing material, each layer including a free tongue-shaped part arranged extending in in an overlapping relationship to each other, arranged to faciliate a sliding or gliding movement in relation to each other to an overlapping position, in which the line of extension corresponds to the configuration of an object surrounded by the tongue-shaped parts.
A number of embodiments of pads with shape adapting properties according to the present invention are more fully described below, reference being made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a first embodiment of a pad with shape adapting properties according to the present invention, intended to be applied against an ear-conch of a hearing-shield or similar.
FIG. 2 is a perspective view of an ear-conch with the pad shown in FIG. 1 applied, after that the ear-conch has been placed in a position to surround an ear, and thereafter been removed.
FIG. 3 is a plan view of a breast shield before it is applied against a human breast in a brassiere.
FIG. 4 is a cross-sectional view of a brassiere with the breast shield shown in FIG. 3 applied.
FIG. 5 is a plan view of an embodiment, suitably used as a head shield in conjunction with a protective helmet.
FIG. 6 is a plan view of an embodiment, preferably used as a protective dressing, viewed from the surface of application.
FIG. 7 is a cross-sectional view of the embodiment shown in FIG. 6 arranged at the surface of a wound together with a removable compress.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the embodiment shown in FIGS. 1 and 2, it comprises two adjacently located layers of a plane absorbing material, denominated 1A and 1B respectively. Said two layers 1A, 1B, in relation to each other as two reversed parts, both including a first cut 2 extending adjacent to an outer edge portion, and two edge cuts 3, 3' extending from said first cut at a distance from each other, said first cut 2 and the edge cuts 3, 3' forming a tongue-shaped part, 4 and 4', respectively. Two strips of a self-adhesive material, 5 and 5', are also shown in FIG. 1, located at the surface of the pad intended to contact an ear-conch 6. The self-adhesive strips 5, 5' are protected before application by means of a protective tape or similar.
The adjacently located layers 1A, 1B are joined together at the surrounding outer edge portions, whereby the tongue-shaped parts 4, 4' are arranged to permit a sliding or gliding movement in relation to each other, when a pressure is applied against same.
When used, the protective tape is removed from the self-adhesive strips 5, 5', whereafter the plane pad is applied against the outer free surface of an ear-conch 6. When said ear-conch is applied in a position surrounding an ear, the insertion of the ear into the ear-conch 6 causes the tongues 4, 4' to perform a sliding or gliding movement in relation to each other, in order to adapt to the shape of the ear. Since the edge cuts 3, 3' are arranged extending from the first cut 2 from two points located more adjacent to each other than the outer end points of the first cut 2, having the opposed end points located separated from each other at a distance mainly corresponding to the length of the first cut 2, two mainly triangular parts 7, 7' and 8, 8' respectively, are formed adjacent to each tongue-shaped part 4, 4'. When the ear is inserted into the ear-conch 6, said triangular parts 7, 7', 8, 8' are folded in direction inwardly into the ear-conch 6, thereby forming two opposed wall portions, which together with the tongue-shaped parts 4, 4' effectively shield and protect the inside of the ear-conch 6. An important advantage is, that the parts 4, 4', 7, 7', 8, 8', adapted to the shape of the ear, do not prevent or, to any larger extent, restrict sound waves from an ear-piece, surrounded by the ear-conch 6, whereby said embodiment is eminently suitable for use as a pad with shape adapting properties for ear-phones used in connection with radio or sound equipment.
With reference to the embodiment shown in FIGS. 3 and 4 of a breast shield, the reference numerals used with regard to the embodiment described with reference to FIGS. 1 and 2 have been used to denominate parts with a similar function. The breast shield shown comprises two adjacently located layers 1A, 1B of a plane and absorbing material, joined together at the surrounding outer edge portions. In order to faciliate adaption to the internal concave shape of a brassiere 9, said adjacently located layers 1A, 1B have a mainly circular outer configuration. As discussed with reference to the first embodiment, said layers 1A, 1B also include correspondingly cut out tongue-shaped parts 4, 4', located rotated 180° in relation to each other. The first cut 2 is arranged as a peripherally located curved cut, having a radius preferably exceeding the outer radius of the layers 1A, 1B. The edge cuts 3, 3' are also arranged curved, extending from two points at the first cut 2 located at a distance from the outer end portions of said cut 2, and extending to two points mainly corresponding to the end portions of a first cut in the adjacent layer, 1A or 1B. By arranging said cuts 2, 3, 3' curved as disclosed above, a breast shield is accomplished, which faciliates complete adaption to the shape of the body of each user, since the tongue-shaped parts 4, 4' when applied slide in relation to each other, whereby shape adaption for each application is achieved. A major advantage is, that the breast shield can be carried as a plane unit prior to use, and that it completely adapts to existing variations in shape and size of the bosom when applied.
A further embodiment is shown in FIG. 5, intended to be used as a head shield, e.g. together with a protective helmet. Previously used reference numerals have been used to denominate parts with a function basically similar to the embodiments already descussed. The head shield comprises two layers 1A, 1B, joined together at the surrounding outer edge portions. As disclosed with reference to the breast shield, the head shield has a mainly circular configuration, having correspondingly cut out parts, rotated 180° in relation to each other. In view of the fact that the head is inserted a rather long distance into the helmet, the first cut 2 is located rather adjacent to the outer peripheral portion of the joined layers 1A, 1B, and the peripheral portions located on each side of the edge cuts 3, 3' are well suited to extend downwardly from the helmet, thus acting as protective shields for the ears of the user.
FIG. 6 discloses a further embodiment, intended to be used as a protective dressing. Said embodiment includes also two adjacently located layers 1A, 1B of a preferably absorbing material, joined together at the outer edge portions, and having tongue-shaped parts 4, 4', rotated 180° in relation to each other. Each layer 1A, 1B is arranged with a first cut 2, located adjacent to one edge portion, defining a free edge portion of the tongue-shaped parts 4, 4', which are further defined by means of two curved edge cuts 3, 3', extending basically as discussed previously with reference to the embodiment of a breast shield. The protective dressing also includes a surrounding strip of self-adhesive material 5, preferably protected by means of a protective tape or film, which when removed facilitates application to a body member to cover the surface of a wound, intended to be protected by the dressing. Since the tongue-shaped parts 4, 4' can glide or slide in relation to each other, they do not inflict any pressure on the surface of the wound, but efficiently shield same.
The above disclosed embodiment may also be used together with an absorbing compress or pad 10, e.g. for skin burns. An example of this is shown in FIG. 7, in which the protective dressing shown in FIG. 6 it utilized to hold a compress or pad 10, applied against the surface of a wound. In order to completely secure the compress or pad 10, the tongue-shaped parts 4, 4' may be sealed to prevent an opening movement by means of a tape or similar. The compress can be easily replaced by folding the tongue-shaped parts 4, 4' in a direction opposite to each other to an open position, and after replacement they are folded back to the previous overlapping position, thereafter possibly sealed together as previously disclosed.
All the above described embodiments are based on the use of two correspondingly formed layers 1A, 1B, joined together at said layers 1A, 1B outer edge portions. However, for certain applications, the number of layers may exceed two, e.g. four corresponding layers in contact with each other, located rotated 90° in relation to each other. Such an embodiment makes it possible to shield the surface to be protected in a better fashion, while maintaining minimum contact pressure against the shielded surface. The number of layers 1A, 1B may be varied further, with adjacent layers 1A, 1B preferably rotated to each other at an angle corresponding to 360° divided by said number.
It should also be emphasized, that pads with shape adapting properties according to the present invention obviously can be used for numerous other applications than the applications shown and described as examples of field of use. As examples of further applications can be mentioned suspender shields, and also the possibility to accomplish sun protective head wear, as well as other articles for which shape adapting properties are desired or necessary.
The embodiments shown and described also include correspondingly cut layers 1A, 1B, but certain differences may be desired with regard to the shape of the tongue-shaped parts 4, 4' for certain applications. The angle by which adjacent layers 1A, 1B are rotated in relation to each other can also be varied within broad limits, while maintaining an overlapping relationship between the tongue-shaped parts 4, 4'.
The present invention is thus in no way restricted to the embodiments shown and described, which only serve as examples of embodiments within the scope of the inventive thought and the following claims.
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A pad with shape adapting properties, including at least two adjacently located layers of a preferably absorbing material which are joined together in the region of the outer peripheral edge portions of the layers the layers further including a free tongue-shaped portion extending in an overlapping relationship to corresponding parts in remaining layers, the overlapping tongue-shaped parts being arranged to glide or slide in relation to each other to an overlapping position with the line of extension adapted to the configuration of an object covered by the tongue-shaped parts. Opposed portions of the layers defined by cuts surrounding the tongue-shaped portions, are also preferably arranged to act as shape adaptable parts, co-acting with the tongue-shaped parts.
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TECHNICAL FIELD
[0001] The present invention relates to semiconductor processors, sensors, semiconductor processing systems, semiconductor workpiece processing methods, and turbidity monitoring methods.
BACKGROUND OF THE INVENTION
[0002] Numerous semiconductor processing tools are typically utilized during the fabrication of semiconductor devices. One such common semiconductor processor is a chemical-mechanical polishing (CMP) processor. A chemical-mechanical polishing processor is typically used to polish or planarize the front face or device side of a semiconductor wafer. Numerous polishing steps utilizing the chemical-mechanical polishing system can be implemented during the fabrication or processing of a single wafer.
[0003] In an exemplary chemical-mechanical polishing apparatus, a semiconductor wafer is rotated against a rotating polishing pad while an abrasive and chemically reactive solution, also referred to as a slurry, is supplied to the rotating pad. Further details of chemical-mechanical polishing are described in U.S. Pat. No. 5,755,614, incorporated herein by reference.
[0004] A number of polishing parameters affect the processing of a semiconductor wafer. Exemplary polishing parameters of a semiconductor wafer include downward pressure upon a semiconductor wafer, rotational speed of a carrier, speed of a polishing pad, flow rate of slurry, and pH of the slurry.
[0005] Slurries used for chemical-mechanical polishing may be divided into three categories including silicon polish slurries, oxide polish slurries and metals polish slurries. A silicon polish slurry is designed to polish and planarize bare silicon wafers. The silicon polish slurry can include a proportion of particles in a slurry typically with a range from 1-15 percent by weight.
[0006] An oxide polish slurry may be utilized for polishing and planarization of a dielectric layer formed upon a semiconductor wafer. Oxide polish slurries typically have a proportion of particles in the slurry within a range of 1-15 percent by weight. Conductive layers upon a semiconductor wafer may be polished and planarized using chemical-mechanical polishing and a metals polish slurry. A proportion of particles in a metals polish slurry may be within a range of 1-5 percent by weight.
[0007] It has been observed that slurries can undergo chemical changes during polishing processes. Such changes can include composition and pH, for example. Furthermore, polishing can produce stray particles from the semiconductor wafer, pad material or elsewhere. Polishing may be adversely affected once these by-products reach a sufficient concentration. Thereafter, the slurry is typically removed from the chemical-mechanical polishing processing tool.
[0008] It is important to know the status of a slurry being utilized to process semiconductor wafers inasmuch as the performance of a semiconductor processor is greatly impacted by the slurry. Such information can indicate proper times for flushing or draining the currently used slurry.
SUMMARY OF THE INVENTION
[0009] The present invention provides semiconductor processors, sensors, semiconductor processing systems, semiconductor workpiece processing methods, and turbidity monitoring methods.
[0010] According to one aspect of the invention, a semiconductor processor is provided. The semiconductor processor includes a process chamber and a supply connection configured to provide slurry to the process chamber. A sensor is provided to monitor turbidity of the slurry. One embodiment of the sensor is configured to emit electromagnetic energy towards the supply connection providing the slurry. The supply connection is one of transparent and translucent in one embodiment. The sensor includes a receiver in the described embodiment configured to receive at least some of the emitted electromagnetic energy and to generate a signal indicative of turbidity responsive to the received electromagnetic energy.
[0011] In another arrangement, plural sensors are provided to monitor the turbidity of a subject material, such as slurry, at different corresponding positions. In addition, one or more sensors can be provided to monitor turbidity of a subject material within a horizontally oriented supply connection or container, a vertically oriented supply connection or container, or supply connections or containers in other orientations.
[0012] One sensor configuration of the invention provides a source configured to emit electromagnetic energy towards the supply connection. The sensor additionally includes plural receivers. One receiver is positioned to receive electromagnetic energy passing through the subject material and configured to output a feedback signal indicative of the received electromagnetic energy. The source is configured to adjust the intensity of emitted electromagnetic energy to provide a substantially constant amount of electromagnetic energy at the receiver. Another receiver is provided to monitor the emission of electromagnetic energy from the source and provide a signal indicative of turbidity.
[0013] The invention also includes other aspects including methodical aspects and other structural aspects as described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Preferred embodiments of the invention are described below with reference to the following accompanying drawings.
[0015] [0015]FIG. 1 is an illustrative representation of a slurry distributor and semiconductor processor.
[0016] [0016]FIG. 2 is an illustrative representation of an exemplary arrangement for monitoring a static slurry.
[0017] [0017]FIG. 3 is an illustrative representation of an exemplary arrangement for monitoring a dynamic slurry.
[0018] [0018]FIG. 4 is an isometric view of one configuration of a turbidity sensor.
[0019] [0019]FIG. 5 is a cross-sectional view of another sensor configuration.
[0020] [0020]FIG. 6 is an illustrative representation of an exemplary arrangement of a source and receiver of a sensor.
[0021] [0021]FIG. 7 is a functional block diagram illustrating components of an exemplary sensor and associated circuitry.
[0022] [0022]FIG. 8 is a schematic diagram of an exemplary sensor configuration.
[0023] [0023]FIG. 9 is a schematic diagram illustrating circuitry of the sensor configuration shown in FIG. 6.
[0024] [0024]FIG. 10 is a schematic diagram of another exemplary sensor configuration.
[0025] [0025]FIG. 11 is an illustrative representation of a sensor implemented in a centrifuge application.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8).
[0027] Referring to FIG. 1, a semiconductor processing system 10 is illustrated. The depicted semiconductor processing system 10 includes a semiconductor processor 12 coupled with a distributor 14 . Semiconductor processor 12 includes a process chamber 16 configured to receive a semiconductor workpiece, such as a silicon wafer. In an exemplary configuration, semiconductor processor 12 is implemented as a chemical-mechanical polishing processing tool.
[0028] Distributor 14 is configured to supply a subject material for use in semiconductor workpiece processing operations. For example, distributor 14 can supply a subject material comprising a slurry to semiconductor processor 12 for chemical-mechanical polishing applications.
[0029] Exemplary conduits or piping of semiconductor processing system 10 are shown in FIG. 1. In the depicted configuration, a static route 18 and a dynamic route 20 are provided. Further details of static route 18 and dynamic route 20 are described below with reference to FIGS. 2 and 3, respectively. In general, static route 18 is utilized to provide monitoring of the subject material of distributor 14 in a substantially static state. Such provides real-time information regarding the subject material being utilized within semiconductor processing system 10 . Dynamic route 20 comprises a recirculation and distribution line in one configuration. In addition, subject material can be supplied to semiconductor processor 12 via dynamic route 20 .
[0030] Distributor 14 can include an internal recirculation pump (not shown) to periodically recirculate subject material through dynamic route 20 . Subject material having particulate matter, such as a slurry, experiences gravity separation over time. Separation of such particulate matter of the slurry is undesirable. For example, the particulate matter may settle in areas of piping, valves or other areas of a supply line which are difficult to reach and clean. Further, some particulate matter may be extremely difficult to resuspend once it has settled over a sufficient period of time. Accordingly, it is desirable to monitor turbidity (percent solids within a liquid) of the subject material to enable reduction or minimization of excessive settling.
[0031] Referring to FIG. 2, details of an exemplary static route 18 coupled with distributor 14 are illustrated. Static route 18 includes an elongated tube or pipe 19 for receiving subject material from distributor 14 . In a preferred embodiment, pipe 19 comprises a transparent or translucent material, such as a transparent or translucent plastic. Static route 18 is coupled with distributor 14 at an intake end 22 of pipe 19 . Piping hardware provided within the depicted static route 18 includes an intake valve 24 , sensors 26 and an exhaust valve 28 . Exhaust valve 28 is adjacent an exhaust end 30 of static route 18 .
[0032] Valves 24 , 28 can be selectively controlled to provide monitoring 2 of the subject material of distributor 14 in a substantially static state. For example, with exhaust valve 28 in a closed state, intake valve 24 may be selectively opened to permit the entry of subject material within an intermediate container 32 . Container 32 can be defined as the portion of static route 18 intermediate intake valve 24 and exhaust valve 28 in the described configuration. In typical operations, intake valve 24 is sealed or closed following entry of subject material into container 32 . In the depicted arrangement, static route 18 is provided in a substantially vertical orientation. Static route 18 using valves 24 , 28 and container 32 is configured to provide received subject material in a substantially static state (e.g., the subject material is not in a flowing state).
[0033] Plural sensors 26 are provided at predefined positions relative to container 32 as shown. Sensors 26 are configured to monitor the opaqueness or turbidity of subject material received within static route 18 . In one configuration, plural sensors 26 are provided at different vertical positions to provide monitoring of the turbidity of the subject material within container 32 at corresponding different desired vertical positions of container 32 . Such can be utilized to provide differential information between the sensors 26 to indicate small changes in slurry settling.
[0034] As described in further detail below, individual sensors include a source 40 and a receiver 42 . In one configuration, source 40 is configured to emit electromagnetic energy towards container 32 . Receiver 42 is configured and positioned to receive at least some of the electromagnetic energy. As described above, pipe 19 can comprise a transparent or translucent material permitting passage of electromagnetic energy. Sensors 26 can output signals indicative of the turbidity at the corresponding vertical positions of container 32 responsive to sensing operations.
[0035] It is desirable to provide plural sensors 26 in some configurations to monitor settling of particulate material (precipitation rates) over time within the subject material at plural vertical positions. Monitoring a substantially static subject material provides numerous benefits. Utilizing one or more sensors 26 , the rate of separation can be monitored providing information regarding the condition of the subject material or slurry (e.g., testing and quantifying characteristics of a CMP slurry).
[0036] Properties of the subject material can be derived from the monitoring including, for example, how well particulate matter is suspended, adequate mixing, amount of or effectiveness of surfactant additives, the approximate size of the particulate matter, agglomeration of particulate matter, slurry age or lifetime, and likelihood of slurry causing defects. Such monitoring of settling rates can indicate when to change or drain a slurry being applied to semiconductor processor 12 to avoid degradation in processing performance, such as polishing performance within a chemical-mechanical polishing processor.
[0037] Subject material within container 32 may be drained via exhaust valve 28 following monitoring of the subject material. Exhaust end 30 of static route 18 can be coupled with a recovery system for direction back to distributor 14 , or to a drain if the subject material will not be reused.
[0038] Referring to FIG. 3, details of dynamic route 20 are described. Dynamic route 20 comprises a recirculation pipe 50 coupled with a supply connection 52 . Recirculation pipe 50 and supply connection 52 preferably comprise transparent or translucent tubing or piping, such as transparent or translucent plastic pipe.
[0039] Recirculation pipe 50 includes an intake end 54 and a discharge end 56 . Subject material or slurry can be pumped into recirculation pipe 50 via intake end 54 . An intake valve 58 and an exhaust or 14 discharge valve 60 are coupled with recirculation pipe 50 for controlling the flow of subject material. Plural sensors 26 are provided within sections of recirculation pipe 50 as shown. One of sensors 26 is vertically arranged with respect to a vertical pipe section 62 . Another of sensors 26 is horizontally oriented with respect to a horizontal pipe section 64 . Sensors 26 are configured to monitor the turbidity of subject material or slurry within vertical pipe section 62 and horizontal pipe section 64 .
[0040] Individual sensors 26 configured to monitor horizontal pipe sections (e.g., pipe section 64 ) may be arranged to monitor a lower portion of the horizontal pipe for gravity settling of particulate matter. As described below, an optical axis of sensor 26 can be aimed to intersect a lower portion of horizontally arranged tubing or piping to provide the preferred monitoring. Such can assist with detection of precipitation of particulate matter which can form into large undesirable particles leading to defects. Accordingly, once a turbidity limit has been reached, the tubing or piping may be flushed.
[0041] Supply connection 52 is in fluid communication with horizontal pipe section 64 . In addition, supply connection 52 is in fluid communication with process chamber 16 of semiconductor processor 12 shown in FIG. 1. Supply connection 52 is configured to supply subject material such as slurry to process chamber 16 . A sensor 26 is provided adjacent supply connection 52 . Sensor 26 is configured to monitor the turbidity of subject material within supply connection 52 . Additionally, a supply valve 66 controls the flow of subject material within supply connection 52 .
[0042] Although only one supply connection 52 is illustrated, it is understood that additional supply connections can be provided to couple associated semiconductor processors (not shown) with recirculation pipe 50 and distributor 14 . The depicted supply connection 52 is arranged in a vertical orientation. Supply connection 52 with associated sensor 26 may also be provided in a horizontal or other orientation in other configurations.
[0043] Referring to FIG. 4, an exemplary configuration of sensor 26 is shown. The illustrated configuration of sensor 26 includes a housing 70 , cover 72 and associated circuit board 74 . The illustrated housing 70 is configured to couple with a conduit, such as supply connection 52 . For example, housing 70 is arranged to receive supply connection 52 with a longitudinal orifice 76 . Cover 72 is provided to substantially enclose supply connection 52 . In a preferred arrangement, housing 70 and cover 72 are formed of a substantially opaque material.
[0044] Housing 70 is configured to provide source 40 and receiver 42 adjacent supply connection 52 . More specifically, housing 70 is configured to align source 40 and receiver 42 with respect to supply connection 52 and any subject material such as slurry therein. In the depicted configuration, housing 70 aligns source 40 and receiver 42 to define an optical axis 45 which passes through supply connection 52 .
[0045] The illustrated housing 70 is configured to allow attachment of sensor 26 to supply connection 52 or detachment of sensor 26 from supply connection 52 without disruption of the flow of subject material within supply connection 52 . Housing 70 can be clipped onto supply connection 52 as illustrated or removed therefrom without disrupting the flow of subject material within supply connection 52 in the described embodiment.
[0046] Source 40 and receiver 42 may be coupled with circuit board 74 via internal connections (not shown). Further details regarding circuitry implemented within circuit board 74 are described below. The depicted sensor configuration provides sensor 26 capable of monitoring the turbidity of subject material within supply connection 52 without contacting and possibly contaminating the subject material or without disrupting the flow of subject material within supply connection 52 .
[0047] More specifically, sensor 26 is substantially insulated from the subject material within supply connection 52 in the described arrangement. Accordingly, sensor 26 provides a non-intrusive device for monitoring the turbidity of subject material 80 . Such is preferred in applications wherein contamination of subject material 80 is a concern. Utilization of sensor 26 does not impede or otherwise affect flow of the subject material.
[0048] In one configuration, source 40 comprises a light emitting diode (LED) configured to emit infrared electromagnetic energy. Source 40 is configured to emit electromagnetic energy of another wavelength in an alternative embodiment. Receiver 42 may be implemented as a photodiode in an exemplary embodiment. Receiver 42 is configured to receive electromagnetic energy emitted from source 40 . Receiver 42 of sensor 26 is configured to generate a signal indicative of the turbidity of the subject material and output the signal to associated circuitry for processing or data logging.
[0049] Referring to FIG. 5, source 40 and receiver 42 are coupled with electrical circuitry 78 . In the illustrated embodiment, source 40 and receiver 42 are aimed towards one another. Source 40 is operable to emit electromagnetic energy 79 towards subject material 80 . Particulate matter within subject material 80 operates to absorb some of the emitted electromagnetic energy 79 . Accordingly, only a portion, indicated by reference 82 , of the emitted electromagnetic energy 79 passes through subject material 80 and is received within receiver 42 .
[0050] Electrical circuitry 78 is configured to control the emission of electromagnetic energy 79 from source 40 in the described configuration. Receiver 42 is configured to output a signal indicative of the received electromagnetic energy 82 corresponding to the intensity of the received electromagnetic energy. Electrical circuitry 78 receives the outputted signal and, in one embodiment, conditions the signal for application to an associated computer 84 . In one embodiment, computer 84 is configured to compile a log of received information from receiver 42 of sensor 26 .
[0051] Referring to FIG. 6, an alternative sensor arrangement indicated by reference 26 a is shown. In the depicted embodiment, an alternative housing 70 a is implemented as a cross fitting 44 utilized to align the source and receiver of sensor 26 a with supply connection 52 . Supply connection 52 is aligned along one axis of cross fitting 44 .
[0052] In the depicted configuration, light-carrying cable or light pipe, such as fiberoptic cable, is utilized to couple a remotely located source and receiver with supply connection 52 . A first fiberoptic cable 46 provides electromagnetic energy emitted from source 42 to supply connection 52 . A lens 47 is provided flush against supply connection 52 and is configured to emit the electromagnetic light energy from cable 46 towards supply connection 52 along optical axis 45 perpendicular to the axis of supply connection 52 . Electromagnetic energy which is not absorbed by subject material 80 is received within a lens 49 coupled with a second fiberoptic cable 48 . Fiberoptic cable 48 transfers the received light energy to receiver 42 . Sensor arrangement 26 a can include appropriate seals, bushings, etc., although such is not shown in FIG. 6.
[0053] As previously mentioned, supply connection 52 is preferably transparent to pass as much electromagnetic light energy as possible. Supply connection 52 is translucent in an alternative arrangement. Lenses 47 , 49 are preferably associated with supply connection 52 to provide maximum transfer of electromagnetic energy. In other embodiments, lenses 47 , 49 are omitted. Further alternatively, the source and receiver of sensor 26 may be positioned within housing 70 a in place of lenses 47 , 49 . Fiberoptic cables 46 , 48 could be removed in such an embodiment.
[0054] Referring to FIG. 7, another implementation of sensor 26 is shown. Source 40 and receiver 42 are arranged at a substantially 90° angle in the depicted configuration. Source 40 operates to emit electromagnetic energy 79 into supply connection 52 and subject material 80 within supply connection 52 . As previously stated, subject material 80 can contain particulate matter which may operate to reflect light. Receiver 42 is positioned in the depicted arrangement to receive such reflected light 82 a . Associated electrical circuitry coupled with source 40 and receiver 42 can be calibrated to provide accurate turbidity information responsive to the reception of reflected light 82 a . Although source 40 and receiver 42 are illustrated at a 90° angle in the depicted arrangement, source 40 and receiver 42 may be arranged at any other angular relationship with respect to one another and supply connection 52 to provide emission of electromagnetic energy 79 and reception of reflected electromagnetic energy 82 a.
[0055] Referring to FIG. 8, one arrangement of sensor 26 for providing turbidity information of subject material 80 is shown. Source 40 is implemented as a light emitting diode (LED) configured to emit infrared electromagnetic energy 79 towards supply connection 52 having subject material 80 in the depicted arrangement. A positive voltage bias may be applied to a voltage regulator 86 configured to output a constant supply voltage. For example, the positive voltage bias can be a 12 Volt DC voltage bias and voltage regulator 86 can be configured to provide a 5 Volt DC reference voltage to light emitting diode source 40 .
[0056] Source 40 emits electromagnetic energy of a known intensity 7 responsive to an applied current from dropping resistor 87 . Receiver 42 comprises a photodiode in an exemplary embodiment configured to receive light electromagnetic energy 82 not absorbed within subject material 80 . Photodiode receiver 42 is coupled with an amplifier 88 in the depicted configuration. Amplifier 88 is configured to provide an amplified output signal indicating the turbidity of subject material 80 . Other configurations of source 40 and receiver 42 are possible.
[0057] Referring to FIG. 9, additional details of the arrangement shown in FIG. 8 are illustrated. Source 40 is implemented as a light emitting diode (LED). Receiver 42 comprises a photodiode. A potentiometer 90 is coupled with a pin 1 and a pin 8 of amplifier 88 and can be varied to provide adjustment of the gain of amplifier 88 . An exemplary variable base resistance of potentiometer 90 is 100 Ωk.
[0058] Another potentiometer 92 is coupled with a pin 5 of amplifier 88 and is configured to provide calibration of sensor 26 . Potentiometer 92 may be varied to provide an offset of the output reference of amplifier 88 . An exemplary variable base resistance of potentiometer 92 is 500 Ω.
[0059] A positive voltage reference bias is applied to a diode 94 . An exemplary positive voltage is approximately 12-24 Volts DC. Voltage regulator 86 receives the input voltage and provides a reference voltage of 5 Volts DC in the described embodiment.
[0060] Referring to FIG. 10, an alternative sensor configuration is illustrated as reference 26 b . The illustrated sensor configuration includes a driver 95 coupled with source 40 . Additionally, a beam splitter 96 is provided intermediate source 40 and supply connection 52 . Further, an additional receiver 43 and associated amplifier 97 are provided as illustrated.
[0061] A reference voltage is applied to driver 95 during operation. Source 40 is operable to emit electromagnetic energy 79 towards beam splitter 96 . Beam splitter 96 directs received electromagnetic energy into a beam 91 towards supply connection 52 and a beam 93 towards receiver 43 . Receiver 42 is positioned to receive non-absorbed electromagnetic energy 91 passing through supply connection 52 and subject material 80 . Receiver 42 is configured to generate and output a feedback signal to driver 95 . The feedback signal is indicative of the electromagnetic energy 91 received within receiver 42 .
[0062] The depicted sensor 26 b is configured to provide a substantially constant amount of light electromagnetic energy to receiver 42 . Driver 95 is configured to control the amount or intensity of emitted electromagnetic energy from source 40 . More specifically, driver 95 is configured in the described embodiment to increase or decrease the amount of electromagnetic energy 79 emitted from source 40 responsive to the feedback signal from receiver 42 .
[0063] Receiver 43 is positioned to receive the emitted electromagnetic energy directed from beam splitter 96 along beam 93 . Receiver 43 receives electromagnetic energy not passing through subject material 80 in the depicted embodiment. The output of receiver 43 is applied to amplifier 97 which provides a signal indicative of the turbidity of subject material 80 within supply connection 52 responsive to the intensity of electromagnetic energy of beam 93 .
[0064] Referring to FIG. 11, an exemplary alternative configuration for analyzing slurry in a substantially static state is shown. The illustrated static route 18 a comprises a centrifuge 100 . The depicted centrifuge 100 includes a container 102 configured to receive subject material 80 . Plural sensors 26 are provided at predefined positions along container 102 to monitor the turbidity of subject material 80 at different radial positions. Centrifuge 100 including container 102 is configured to rapidly rotate in the direction indicated by arrows 104 about axis 101 to assist with precipitation of particulate matter within subject material 80 . Such provides increased setting rates of the particulate matter. Sensors 26 can individually provide turbidity information of subject material 80 at the predefined positions of sensors 26 relative to container 102 . Such information can indicate the state or condition of the slurry as previously discussed. Centrifuge 100 can be configured to receive samples of slurry or other subject material during operation of semiconductor workpiece system 10 . Information from sensors 26 can be accessed via rotary couplings or wireless configurations during rotation of container 102 in exemplary embodiments.
[0065] From the foregoing, it is apparent the present invention provides a sensor which can be utilized to monitor turbidity of a nearly opaque fluid. Further, the disclosed sensor configurations have a wide dynamic range, are nonintrusive and have no wetted parts. In addition, the sensors of the present invention are cost effective when compared with other devices, such as densitometers.
[0066] In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.
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Semiconductor processors, sensors, semiconductor processing systems, semiconductor workpiece processing methods, and turbidity monitoring methods are provided. According to one aspect, a semiconductor processor includes a process chamber configured to receive a semiconductor workpiece for processing; a supply connection in fluid communication with the process chamber and configured to supply slurry to the process chamber; and a sensor configured to monitor the turbidity of the slurry. Another aspect provides a semiconductor workpiece processing method including providing a semiconductor process chamber; supplying slurry to the semiconductor process chamber; and monitoring the turbidity of the slurry using a sensor.
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This application is a 371 of PCT/GR94/00011 filed Jun. 3, 1994.
This application is a 371 of PCT/GR94/00011 filed Jun. 3, 1994.
FIELD OF INVENTION
The invention describes an original gasification method of low calorific value solid fuels e.g. lignites and peats with pyrolysis and oxygen or oxygen-steam gasification in two stages. Additionally it describes an original process by which the gases produced are utilised a Co-Gas advanced system for producing high amounts of electric energy in an operation running without environmental pollution.
BACKGROUND OF INVENTION
With the existing crisis in securing adequate amounts of energy and since petroleum supplies are not regular in availability and price, the national programs for producing electric energy rather prefer to develop local energy sources. In this preferred development, coal is the main source to consider which is the first fuel to be used in power production and is more abundant and more regularly distributed in the World than oil. The resources in coal are divided in low and high thermal value. They are also divided according to their sulfur content which by burning the solid fuels becomes sulfur dioxide creating toxic environmental pollution. With that problem, the utilization of solid fuels is restricted to those containing low sulfur and create as low as possible environmental damage.
In relation to coal and to its utilization in the production of electric energy it is observed that by its burning, the result in electric energy is low, it releases high amounts of sulfur dioxide, fly ash and nitric oxides and it creates high corrosion in the equipment.
Additionally, by burning solid fuels high amounts of carbon dioxide are produced which today are considered a major pollution factor, being the main source for the green-house conditions emerging in our Planet. And all these environmental and production problems appear more critical by the use of solid fuels of low calorific values such as lignites and peats.
To face these problems today there exist solutions leading to the reduction of the sulfur content in those low calorific fuels and to the neutralization of the combustion gases.
Those solutions, however, are costly and the corrections offered, because of cost, do not make them attractive. A better approach appears to be the gasification of those low calorific fuels as an action attractive today in spite of its leading to high losses of energy. With total gasification the gases can be washed to separate them from the toxic gases and the flying ash but with total gasification the thermal value is further reduced to 65-70% and expensive industrial installations are needed in the operation.
In the meantime, however, with the development of gas turbines in the production of power more economical solutions are available to utilize gases. Our original solution is such a method which utilizes the fuel gases produced in Co-Gas advanced systems by which the degree of produced electric energy with the use of air turbines and combined cycle is improved. For operating the gas turbines, however, we need fuel gases free of corrosives and free of tars and liquid byproducts, but also of the highest possible thermal value.
SUMMARY OF INVENTION
Considering those developments, the technological characteristics of lignites and peats of low calorific value have been studied and it has been discovered that those solid fuels either as they are received or after deashing (described in another invention) show high efficiency in running in such an advanced system for producing electric energy because those fuels are pyrolyzed at high extent (40-85%), highly exothermally without forming tars and liquid byproducts. The pyrolysis of those low calorific value fuels is optimized at 400°-600° C., and the pyrolytic treatment is highly exothermic in character. The pyrolysis residue is received in high carbon purity with thermal value of 4.000-6.000 Kcal/Kg without ash, or with 2.200-4000 Kcal/Kg with ash. It has been studied for the described invention the gasification of that carbon residue with oxygen and preferably with oxygen-steam and has been discovered that the fuel gases produced are of extremely high thermal value and received at high temperatures of 900°-1.000° C. and that the gasification achieves the complete utilization of carbon. According to this procedure it has been discovered for the said invention that the two-stage gasification of lignites and peats achieves a very high thermal efficiency, and the oxidative gasification does not lead to tars or liquid byproducts.
It has been discovered for the present invention that the pyrolytic treatment proceeds exothermally producing 350-600 Kcal/Kg at 600° C. and the exothermic output in energy is related to the degree of pyrolysis. To that quantity of energy is added the thermal content of the fuel gases and the thermal exchange of the bottom ash and the fuel gases produced in the oxidative gasification.
More heating needs can be adopted on the incoming solid fuels as shown in diagram 1. Thus, the conditions by which the thermal balance of the pyrolytic treatment is covered without using carbon thermal energy have been also studied. And this leads to high energy economy and to high energy utilization of the low calorific solid fuels.
The two stages of gasification, the pyrolysis treatment and the gasification proper (with oxygen or with oxygen-steam) have been discovered in the present invention beneficially to lead to products of different chemical character. Pyrolysis is a reductive treatment in which sulfur is gasified as hydrogen sulfide and the oxidative treatment is oxidative in chemical character in which sulfur is gasified as sulfur dioxide. The inventor has discovered a solution for neutralizing the respective sulfur gases by creating conditions to run the fuel gases to a Claus reactor. With mixing those fuel streams, after first utilization of their thermomechanical energy in a turbine system, with temperatures of 600° C. and at a pressure of 30 at, and feeding them to a Claus catalytic reactor the sulfur gases release product sulfur
2H.sub.2 S+SO.sub.2 →3S+2OH.sub.2
That possibility to neutralize the sulfur gases beneficially simply with production of valuable sulfur is a main advantage of the invention. It satisfies a goal for R & D activity: to develop a method of producing electric energy from low calorific value solid fuels which does not create toxic pollution problems from sulfur dioxide and from flying ash. The derived sulfur is collected in high purity and may in small amounts be taken with the gases flow from where it is washed with water and collected.
Another advantage of the invention is that the fuel gases are received to pressures of 30 at. developed during the pyrolytic treatment and form a working pressure in the two gasification treatments and in the Claus unit. The fuel gases are received at temperatures of 600° to 900° C. and at pressure 30 at., free of corrosive substances and sulfur gases.
Another basic advantage of the invention is the experimentally proved evidence that the low calorific value solid fuels (lignites and peats) are pyrolyzed exothermally because of the oxygen content of the organic materials, which resemble wood.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a diagrammatic representation of the gasification and utilization of lignites and peats according to a preferred embodiment of the claimed method.
DETAILED DESCRIPTION
Wood and woody biomass are known to pyrolyze exothermally at temperatures higher than 400° C. and that has been utilized beneficially in the past for the distillation treatment of wood and recently in the pyrolytic treatment of garbage biomass. The low calorific value solid fuels (lignites and peats) have the following woody consistency.
TABLE 1______________________________________The consistency of Lignites and PeatsConstituents Lignites Peats______________________________________pH 5.8-6.9 4.6-5.4Ash 15-35 6-20.5Waxy substances etc. 5.2-6.8 8.1-8.3Humic acids 20-33.8 18-34.1Humins 30-40 37-42.1Holocellulose 31-35 26.1-32.9d-cellulose 8-15 10.5-12.0______________________________________
With the above which determine the nature of the pyrolytic tendency and the result of the gasification with oxygen or with oxygen and steam a system is formed with profitable thermal balance in thermal exchanges and final results. The thermal operational parameters determine:
a. That the heating of the solid fuels to the pyrolytic treatment is affected by the rejected thermal energy, that is thermal energy from off-gases, bottom ash, etc.
b. That the pyrolytic gasification is exothermic, producing 250-600 Kcal/Kg thermal energy with formation of operational pressures up to 30 atm. and it is advanced without being influenced by moisture or ash presence and it is a reaction of reductive chemical character.
c. That the Claus reaction of neutralizing the sulfur gases is spontaneous at temperatures 600° C. and at pressures of 30 at. of the fuel gases and provided that the molar ratio of H2S/SO2 is 2:1, the reaction is quantitive.
d. That the installation for utilizing the procedure should operate under pressure 30 at. and at temperature of fuel gases up to 900° C.
The drying of the solid fuels e.g. lignites or peats as they are or after a deashing treatment with the fuels pulverized form, first with mechanical dewatering and then with heating to 180°-300° C. with exchange of the ash thermal energy received at 1.000° C. and of the thermal energy of the off-gases so that to be finally received as off gases at 180°-300° C.
The pyrolytic treatment starts with the solid fuel e.g lignite at temperature 180°-300°, while to be pyrolyzed, temperatures of 450° to 600° are needed. To form those temperatures the following thermal sources are used a) that of exchange on the gases of the oxidative gasification which are received at 1000° C. and can offer 200° C. to the pyrolysis mass (cooled down to 600° C.) and b) that of the thermal energy resulting from the exothermal pyrolytic reaction which will increase temperatures by 200° to 300° C.
With those thermal offers the pyrolytic treatment attains temperatures of 600° C. and higher. The energy coverage of the pyrolytic treatment is controlled by heating arrangements on the incoming lignite if needed, nevertheless, this is depending largely on the relative extent of the pyrolysis and of the oxidative gasification treatments.
The gasification of the carbon pyrolysis residue with oxygen or preferably with oxygen steam is added at 600° C. with high carbon purity and in porous stage proceeds very energetically with quantitative transformation of the contained carbon and rapid increase of the temperature to 900°-1000° C. The losses in thermal energy at the oxidative treatment are comparably low, lower than 12% and this refers to the 50% of total. The actual thermal energy loss is under 6% which is low for total gasification treatment and a high energy benefit.
The two streams of gasses the one from pyrolysis and the one from gasification with oxygen or with oxygen steam are mixed as they are received or after energy exchange utilization in a turbine. They are then directed to the Claus unit which operates under pressure. In the Claus unit the sulfur gases are neutralized and the fuel stream is received free of corrosive gases.
An analysis of gases produced in the two reactors that of pyrolysis and that of oxygen gasification for a number of greek lignites and peats are given in the following Table 2 as maxima and as minima of composition.
TABLE 2______________________________________The composition of the gas fuels from pyrolysis andoxygen gasification From OxygenFrom Pyrolysis, % Gasification, %______________________________________Methane 30-35% Carbon monoxideCarbon monoxide 30-50% 35-40%Carbon dioxide 2-6% Carbon dioxideHydrogen 16-22% 16-22%Hydrolgen Sulfide 1-3% Hydrogen 40-60% Sulfur dioxide 1-2%______________________________________
The procedure of the pyrolytic reaction on a number of solid fuels of low thermal value gave the results of Table
TABLE 3______________________________________The pyrolytic reaction of low caloric value lignitesand peats in % (free of ash and in dry form) Ptolemais Megalopolis Aliveri (North (Peloponessus, (Euboea,temperature Peat Greece) Greece) Greece)______________________________________400° 15.2% 17.3% 35.4% 16.8%450° 22.4 23.5 44.3 23.4500° 34.24 35.28 52.4 37.2550° 34.48 39.43 67.42 44.64600° 44.00 44.24 75.42 51.00650° 44.63 46.6 79.38 56.00Ash content 11.55% 10.8% 20.6% 11.5%Kcal/Kg of 4.400 5.100 4.400 5.400the solid fuelKcal/Kg of the 4.465 5.200 4.020 5.730coal residue______________________________________
In the drawing, the utilization of the gases produced for electricity production are easily recognized as are the energy benefits obtained according to the present invention.
The production sequence consists of two pressure reactors in series that of pyrolysis and that of gasification with oxygen. The pyrolysis reactor is designed to operate at a temperature of 700° and pressure of 50 atm and is of fluidized bed type with automated systems for carbon feeding, and for withdrawing the products obtained: the carbon residue and the fuel gases.
The gasification reactor is designed to operate at temperatures up to 1200° and at pressures up to 50 atm and it is of solid bed type with automated systems for feeding and introducing oxygen and for releasing ash and the gases produced.
Another possibility for applying the present invention is a combination of the pyrolytic treatment with burning the carboneous residue in the existing boiler producing pressure steam.
According to this solution the solid fuels e.g. lignites or peats are introduced to the pyrolysis reactor with moisture up to 60% or in dry or semidried form and the fuel gases produced are fed to a turbine for utilization of their thermomechanical energy then are washed and the hydrogen sulfide present is neutralized by known procedures such as in a combination with the Stratford process. The fuel gases after this are burned to produce high amounts of electric energy in a combined-circle advanced system. The carbonareous residue in this case is burned in the existing boiler to produce pressure steam to run existing steam turbine or newly installed. With that solution the electric energy output is about three times higher than the one obtained today and the desulfurization covers the 70% of sulfur total presence in the solid fuel.
In the present invention it has been shown that the pyrolytic treatment is not influenced by the moisture of ash presence and that this treatment makes an energetic transformation pattern because the energy use is taken by the products produced, the gases and the carbon residue, and the steam formed actually increases substantially the gas volume and their energy content. Apart from utilizing the solid fuel optimized by biorefining release, the exothermic reaction is a substantial contribution in energy quantity and as energy source.
The fuel gases from the reactors are mixed and directed to a turbine to release part of the thermomechanical energy as electrical energy and then are introduced to a Claus reaction unit. In the Claus unit the gases for optimization should have a temperature of 400-450 and a working pressure. The thermomechanical energy can be also used in steam generation by thermal exchange.
At the end the fuel gases contain thermal energy up to 95%+ of thermal energy of the initial solid fuel in biorefining utilization and in exothermic reaction energy addition.
The fuel gases are fed into an advanced combined circle utilization for electric energy output. This, according to this invention, can exceed the 65% in combination of the turbine for thermomechanical energy utilization.
The yield in electrical energy today is 1.1 Kg of 3.000 Kcal lignite per KWh or with lignites and peats of thermal content 800-1200 Kcal/Kg the yield is 1.8-4.1 Kg/KW of electric energy. With the described invention the yield in electricity is impressively high, 0.41-0.62 Kg of lignite or peat/KWh since the lignites and the peats of low calorific content are utilized according to their energy content in dry form and additionally by the contribution of a sizable exothermic reaction which adds 20-30% in energy increase. In view of the above, it can be appreciated that the present invention, in utilizing low caloric solid fuels with pyrolytic tendency of 30% to 80%, advances high yields in electricity production which is comparable to solid fuels of high thermal value and to oil, in an operation beneficially running entirely pollution free.
The present invention, therefore, introduces a procedure for electricity production of low cost from low calorific solid fuels which have a wide distribution in all the World in an operation which although it produces high amounts of electricity also introduces an operation running free of pollution from flying ash and from SO2 and can be arranged also to be free of nitric oxides, thus to be entirely pollution free. It also leads to a visable reduction of CO2 release of 75% per production unit.
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A process for producing fuel gases from a solid fuel including carbonaceous material and having a calorific value of between about 800 to 3,000 Kcal/Kg. The process includes a) pyrolyzing the solid fuel under reaction conditions and for a time sufficient to pyrolyze about 40-80% of the carbonaceous material whereby to form a first gas and a carbon residue without formation of tar, and b) gasifying carbon residue to form a second gas by heating the carbon residue in the presence of oxygen or oxygen-steam; or burning the carbon residue. In a preferred embodiment, the first and second gases are mixed under conditions to neutralize contained sulfur gases by a Claus reaction.
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FIELD OF THE INVENTION
The present application relates to truss systems used in the construction industry, and in particular, relates to a column hung truss system for forming of concrete floors.
BACKGROUND OF THE INVENTION
Flying form trusses are used to form concrete floors in multi-story structures. Some flying form truss systems transmit the poured concrete load directly to the floor slabs below and in fast construction cycles, the concrete floor below may not be fully cured. For this reason, reshoring of the lower concrete floor may be necessary to transmit the loads to a slab which is fully cured. Reshoring takes additional time and also limits the access to some lower levels which are effectively cured.
To overcome the above problems, it is known to use column mounted flying form truss systems designed to transfer the concrete load to the columns as opposed to the lower floors. Column mounted truss systems allow full access to the lower floors and the follow-up trades can be working on any floors which have been previously poured. With this arrangement, the construction cycle can be reduced.
Column mounted flying truss systems are most commonly used with flat slab construction but can accommodate shallow internal beams and spandrel beams. Any projection from the slab soffit increases the stripping distance the support jacks must lower the truss to allow removal.
Flying form systems typically use two large I-beams which run parallel to the building support columns with the I-beams being supported by shoring jacks secured to the columns. The shoring jacks are adjustable in height and typically have a roller associated therewith to allow lowering of the I-beams and sliding of the truss out of the formed bay. These I-beams have a series of transverse beams secured to and extending perpendicular to the I-beams. A series of runner beams which typically support a plywood deck are secured and extend perpendicular to the transverse beams.
The construction design of the building in combination with the expertise of the contractor typically determine whether a column hung truss system or a shoring frame truss system will be used. Column hung truss systems are often used for condominium and hotel construction, particularly when a short construction schedule is needed.
The transverse beams are of a length which is primarily determined by the width of the bays used in the building. The bay width is the distance between the columns. Surprisingly the bay width of different buildings varies substantially and thus different lengths of transverse beams are required. It is known to use composite transverse beams formed using U-shaped channel sections placed in back to back relationship and secured in an overlapping adjustable manner. Typically mechanical fasteners are used to secure the channels to form the appropriate length of transverse beams. It is desirable to produce relatively stiff transverse beams such that the spacing between the beams can be large, thereby reducing the number of transverse beams required and reduce the weight of the system. It is desirable that the overall weight of the flying truss be reduced to ease the movement thereof and to accommodate the crane capacity used for the building construction.
The present invention provides improvements to the transverse beams and improvements to truss systems used in concrete forming.
SUMMARY OF THE INVENTION
An extruded elongate metal component according to the present invention comprises in cross section, a hollow section having a top securing section first and second opposed side securing sections and a bottom securing section. The top securing section includes a recessed bolt slot extending the length of the structural component. The side sections have complimentary shapes with the first side securing section including a recess extending the length of the structural component, the second side securing section includes a projecting section sized for snug receipt in the recess of first side section. The bottom securing section includes at least one downwardly projecting securing flange extending the length of the structural component.
According to an aspect of the invention, the extruded elongate structural component is an extruded aluminum alloy component.
In a further aspect of the invention, the hollow section of the structural component is of a generally rectangular cross section.
In yet a further aspect of the invention, each side section has a series of holes extending therethrough and aligned with the holes through the other side section.
In yet a further aspect of the invention, the at least one downwardly projecting securing flange is two downwardly projecting securing flanges disposed in parallel relationship either side of the center line of the bottom section.
In yet a further aspect of the invention, the securing flanges include a series of securing holes passing therethrough and spaced in the length of the structural component.
In yet a further aspect of the invention, the recess in the first side section is a shallow U-shaped section which dominates the first side section and the projecting section of the side section includes opposed upper and lower shoulders for engaging sides of the shallow U-shaped section.
An assembled structural beam, according to the present invention, comprises a top chord and a bottom chord which are mechanically connected by a series of diagonal connecting members. The top chord includes on an upper surface, a longitudinally extending bolt slot. The bottom chord includes on a bottom surface, a longitudinally extending bolt slot. Each of the top chord and the bottom chord have two opposed side surfaces with a shallow channel recess in one side extending the length of the chord, and a complementary projection on the opposite side extending the length of the chord and sized for receipt in the shallow channel recess. Each of the top chord and the bottom chord are extruded components and include a securing flange which cooperates with the diagonal connecting members to secure the top chord to the bottom chord.
In an aspect of the structural beam, vertical connecting members are included.
In a preferred aspect of the invention, the top chord and the bottom chord of the assembled structural beam are of the same cross section.
In yet a further aspect of the invention, the top chord includes a hollow cavity extending the length thereof.
In yet a further aspect of the invention, the chords and the diagonal connecting members are extruded aluminum alloy components.
In yet a further aspect of the invention, the diagonal connecting members are secured to the chords using mechanical fasteners.
In yet a further aspect of the invention, the top chord includes on an upper surface a longitudinally extending bolt slot and the bottom chord includes on a bottom surface, a longitudinally extending bolt slot.
The present invention is also directed to a header beam which is adjustable in length. The header beam comprises two beam sections secured one to the other in an overlapping manner. Each beam section is an assembled structure having a cop chord, a bottom chord and a series of connecting members secured thereto between. The top chord and the bottom chord of the beams include interfitting surfaces which maintain longitudinal alignment of the beam sections relative to each other. The beam sections further include a series of holes in the top chord and bottom chords and a plurality of structural fasteners passing through aligned holes in the chords which in combination with the interfitting surfaces, mechanically secure the beam sections.
An adjustable in length header beam according to an aspect of the invention, as each of the beam sections being of the same cross section.
In yet a further aspect of the invention, the top chord and the bottom chord are of the same cross section.
In a further aspect of the invention, the chords are formed by extrusion and each chord has an extending member at one side and a corresponding receiving channel on the opposite side thereof.
In yet a further aspect of the invention, the header beam is stackable with like header beams with the interfitting surfaces engaging to partially maintain the stack of beams.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in the drawings, wherein:
FIG. 1 is a perspective view of the column hung flying truss;
FIG. 2 is a side view of the column hung truss;
FIG. 3 is a partial perspective view of the column mounted jack;
FIG. 4 is a perspective view of a beam section;
FIG. 5 is an exploded perspective view of part of a beam section;
FIG. 6 is a partial perspective view of a beam section supporting a runner beam;
FIG. 7 is a side view of two beam sections secured together;
FIG. 8 is a partial perspective view showing the securement of the beam sections;
FIG. 9 is a sectional view showing two secured beam sections;
FIG. 10 shows details of the column jack;
FIG. 11 shows details of a support bracket used to secure the beam sections;
FIG. 12 is a side view of a secured transverse beam;
FIG. 13 shows details of a secured beam section to the support bracket;
FIG. 14 shows two trusses at a support column;
FIG. 15 shows further details of the column hung jack.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically shows a bay of a building having the flying truss mounted to the columns in preparation for pouring of a concrete floor. The flying truss 2 has two main beams 4 which extend between columns 12 of the building and are supported by the columns by column mounted jacks 9 mechanically secured to the columns. The bay 11 of the building is generally the space between the columns 12 . The main beams 4 have connected to them, a series of transverse beams 6 which are of a composite structure. These transverse beams are generally perpendicular to the main beams 4 . A series of runner beams 8 are attached to the upper surface of the transverse beams 6 and support the plywood deck 14 . Once the reinforced concrete floor 10 has been poured and partially cured, such that it can support its own weight, the flying truss may be lowered on the column jacks 9 and moved out of the bay in preparation for locating between the columns for pouring of the next floor or an adjacent bay.
FIG. 2 shows the various elements of the flying truss 2 supported within the bay 11 of the building.
FIG. 3 shows various details of the column mounted jack 9 , the main beams 4 and the transverse beams 6 . As shown, the transverse beams 6 are of a composite design and are of a depth which extends below the main beams 4 . The increased depth provides greater stiffness and allows further separation of the transverse beams. The spacing between transverse beams 6 will depend on the concrete load, however, this spacing is typically 64 to 108 inches. This spacing is approximately double the spacing necessary if standard bar joist beams are used to carry the same load. The distance between the aluminum alloy runner beams 8 is 16 to 19 inches depending upon the plywood and the thickness of concrete to be poured.
As shown in FIG. 3 , the runner beams 8 are preferably of an I-beam section with a center channel for receiving a nailer strip. In this way, the plywood deck 14 may be secured by screws or nails to the nailer strip located in the runner beams.
FIG. 7 shows details of the composite transverse beam 6 . The composite transverse beam is made of two beam sections 44 and 46 which are mechanically secured by a series of bolt and nut combinations 48 , at the overlapping ends of the two beams. Both the bottom chord and the top chord are mechanically secured using a series of holes in the chord members as generally shown in FIG. 9 .
One beam section 44 is shown in FIG. 4 . This beam section includes a top chord 20 , a bottom chord 22 and a series of diagonal bracing members 24 and a series of vertical members 26 . Members 24 and 26 are mechanically secured to the top and bottom chords. Each of the chords is of the same structure and has a series of holes 22 extending in the length of the chords. These holes pass directly through the chords and are used to mechanically fasten two sections, one to the other.
A top chord 20 is shown in FIG. 6 , and has a generally rectangular shaped enclosure 30 , having a top portion 32 , opposed side portions 34 and 36 , and a bottom portion 38 . The top portion 32 includes a longitudinally extending bolt slot 50 used to mechanically fasten the runner beams 8 to the transverse beams 6 . The side portion 34 includes an outwardly extending elongate rail 52 which is sized for receipt in the U-shaped receiving channel 54 in the opposite side 36 . The bottom portion 38 includes downwardly projecting securing flanges 40 and 42 centered either side of the center line of the chord and uses to mechanically secure the diagonal and vertical connecting members 24 and 26 . As shown in FIG. 5 , the securing flanges 40 and 42 have a series of holes 43 at various points in the length of the chord and is used to fasten the connecting members by means of bolts 45 .
The flanges 40 and 42 are positioned inwardly of the sides 34 and 36 with the entire mechanical connection of the connecting members 24 and 26 located in a non interference position when two sections are secured, one to the other, as shown in FIGS. 7 , 8 and 9 . The side portions of the enclosure 30 are designed to mate and form a mechanical connection opposing racking of the sections when a load is carried by the transverse beam 6 . The projecting rail 52 of one beam section 44 is received in the adjacent receiving slot 54 of the other chord member. Bolts 48 pass through the holes and mechanically secure one beam section to the other beam section to form the transverse beam structure 6 . The length of the transverse beam 6 may be varied by releasing of the mechanical fasteners 48 and moving the sections one to the other until the desired length is achieved. In this way, the transverse beams 6 can be adjusted in length to accommodate different bay widths. This composite structure also allows for salvaging of components if certain portions of the transverse beam are damaged.
As can be seen, the top and bottom chords are of the identical section and merely reversed in orientation. If damage occurs to either the top chord or the bottom chord, a new chord member can be inserted. It can further be appreciated that damage may have occur to only part of the chord and a portion of the chord may be salvaged for another application.
FIG. 11 and FIG. 12 shows details of the bracket 100 used to secure the transverse beams 6 to the main beams 4 . The bracket 100 is mechanically secured to the web 3 of the main beam by a nut and bolt connection which passes through the web and passes through holes in the bracket. The transverse beams are mechanically secured to the brackets using the series of holes in the top chord and appropriate holes provided in the bracket 100 . A further brace can extend from the bracket to the bottom chord to increase the stability. Furthermore, the bottom chord members of the parallel spaced transverse beams 6 can be tied one to the other using the bolt slot provided in the bottom chord member to provide bracing. This increases the stiffness and stability of the system.
As shown in FIG. 12 , the transverse beams 6 are secured to the main beams 4 at a position below the top of the main beams 4 . The transverse beams 6 are designed to support the extruded aluminum runner beams 8 which have an overall height of approximately six and one half inches. The upper surface of each runner beam 8 is three and one half inches above the top of the main beams 4 . In this way, a series of wooden four-by-fours 110 can be positioned on the main beams 4 and across the main beams 4 to surround the column 12 and provide a support surface for the plywood deck 14 adjacent the column. In this way, the packing around the columns for supporting the concrete floor adjacent the column is relatively simple and straightforward. This aspect is clearly shown in FIG. 14 .
The transverse beams 6 are of a design such that the beam sections cooperate with one another along the top and bottom chords to oppose racking of the sections when the beams are loaded. The beam sections are mechanically secured one to the other and allow for ready adjustment in length of the transverse beams. As can be appreciated, for a given building structure, the bay width is essentially constant and therefore, the truss can be used for forming of the bay floor and then repositioned for forming of the floor thereabove. In many cases, the bay sizes will be somewhat standardized and there will be no requirement to vary the length of the transverse beams. In some cases due to the particular building design, the bay width may be somewhat unusual and thus, the transverse beams can be adjusted in length, to allow formation of the truss of appropriate width.
Details of the column hung jack assemblies are shown in FIG. 15. A U-shaped saddle member 120 includes a column engaging plate 122 having two outwardly extending arms 124 and 126 . The column engaging plate 122 is mechanically secured to the column using any of the series of holes 128 . These holes allow for aligned or offset bolts. The adjustable jack 130 is received between the arms 124 and 126 and has an overlapping top slide plate 132 . The jack has a securing flange 134 which cooperates with releasable pins 136 to locate the jack at one of three positions shown in FIG. 15 . Each position is shown by one of the pair of vertically aligned locking pin ports 138 . The jack assembly includes a screw member 140 which can be adjusted by means of the bolt adjustment 142 for raising and lowering of the support plate 144 . The support plate 144 engages the lower flange of one of the main beams 4 . To allow movement of the truss out of the bay, the jack is adjusted to drop the main beams onto the support rollers 146 and thereafter, the truss may be moved out of the bay and raised to the next level. The column hung jack assembly of FIG. 15 allows for minor variation in the spacing of the columns and allows for effective transfer of the loads through the jack to the columns 12 .
It is preferred that the composite structural beams 44 and 46 be made of an extruded aluminum alloy components or similar lightweight high strength component. The top chord and the bottom chord are of the identical structure and the diagonal connecting members and the vertical members are tube members with relatively thick sidewalls which have the holes for connecting of the member to the chords and thinner end walls.
The transverse beams 6 can be spaced along the main beams 4 anywhere from 64 inches to 108 inches apart. The actual separation of the transverse beams 6 will be determined by the thickness and weight of the slab being poured.
The flying form truss, due to the large size thereof, is assembled onsite and is dismantled once the building is complete. The individual components are transported to and from the site and between jobs are stored in a construction yard. The transverse composite beams can be stacked sideways, one on top of the other, and interfit to maintain the stack. This stacking is particularly convenient with the individual beam sections. The projecting, elongate rail 52 is received in a U-shaped receiving channel of an adjacent beam section. This stabilizes the stack and is helpful in transportation and storage.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
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An extruded metal structural component has a hollow generally rectangular section with the sides of the rectangular section adapted to interlock and engage with other structural components of the same cross section. The generally rectangular section includes on one side a shallow “U” shaped channel and the opposite side includes a projecting portion for mating receipt in the “U” shaped channel of a second structural component. The structural component includes a downwardly extending securing flange for engaging and securing connecting members when two such structural components form the top and bottom chord of a structural beam.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a toilet flushing device with water saving features, and, in particular, to a toilet flushing device with a dual flush mechanism which uses a single handle and a single flush valve to effect both a short flush and a long flush. In addition, the present invention relates generally to a toilet trapway reseal device which selectively directs water from the reseal water hose into the tank overflow tube.
Various dual flush toilet mechanisms have been developed over the years for the purpose of providing the option of a full or long flush cycle for solid waste, or a short or partial flush cycle for liquid waste to save water during flushes that do not require the use of a full flush cycle. Conservation of natural resources such as water is important. Toilets which use less water to flush waste are most desirable.
Prior art dual flush mechanisms characteristically fall into two general categories. The first type of device includes dual flush mechanisms that utilize two separate flush valves. The flush valve used for the full flush is located at a lower level in the tank than the flush valve used for the short flush cycle. An example of this type of dual flush mechanism construction is found in Brown U.S. Pat. No. 1,960,864. Brown describes a dual flush valve operating device for a flush toilet wherein two trip lever arms of different lengths have a common fulcrum and are independently pivoted as the handle is rotated clockwise or counterclockwise.
The second type of dual flush mechanism characteristically includes two separate handles, one to effectuate the long flush and the other to effectuate the short flush. Activation of either handle causes a single flush valve in the tank to be raised to different heights. For example, Harney U.S. Pat. No. 4,881,279 describes a two-handle system wherein turning of the first handle results in a regular, full flush, and turning of the second handle results in a partial raising of the flush valve to actuate a short or partial flush. Harney uses a complicated system to effect the short flush cycle.
Lester U.S. Pat. No. 2,001,390 uses a clutch device on the rod of the flush valve to hold the flush valve in a partial raised position during the short flush cycle.
Most users are accustomed to a toilet with a single handle, and most toilets use a single flush valve as part of the toilet tank construction. Accordingly, an improved dual flush device for a toilet tank having a single flush valve actuated by a single handle for effecting either a short flush cycle or a long flush cycle is desired. It would also be desirable to provide such a dual flush device that can be retrofitted to a conventional toilet tank.
Another source of wasted water in a toilet tank occurs through the reseal water hose. After a toilet is flushed, the tank must be refilled with fresh water. In addition, some water must be supplied to the bowl or the trapway during refilling of the tank to insure that the trapway is resealed. In conventional toilets, the reseal water hose extends from the tank inlet water control and directs water into the tank overflow tube (which leads to the bowl or trapway) the entire time that the tank is refilling. This causes a waste of water since once the trapway is resealed, excess water will flow into the drain.
Furthermore, a dual flush device in the toilet tank complicates the water flow operation since two different refill patterns are required. Because the refill cycle after the long flush duration is greater than the short flush duration in a dual flush application, the volume of reseal water dedicated to insuring that the trapway in the toilet bowl is resealed after the long flush is typically greater than the volume of water dedicated to resealing the trapway during the short cycle. This may result in an underfilled trapway seal for the short flush which can create a health hazard. Yet, on the other hand, during the long flush, there is an overfilled trapway seal which wastes water that could have been better utilized, for example, for flushing solid waste and refilling the tank.
Prior art water reseal constructions have identified this problem of wasted water from the reseal hose and have attempted, in a less than completely satisfactory way, to provide a solution. For example, Lazar U.S. Pat. No. 5,341,520 describes a dual capacity toilet flusher where the end of the reseal hose is supported on a movable platform construction which selectively moves the refill hose horizontally away from the overflow tube when the bowl is refilling. Comparetti U.S. Pat. No. 4,910,812 describes a complicated toilet system wherein the overflow tube pivots out of the path of the reseal hose water during part of the flush cycle.
However, heretofore, an acceptable, reliable and simple reseal water hose assembly has not been provided which can permit the reseal water hose to direct water into the tank during part of the flushing cycle and thereafter permit the reseal water hose to direct water into the overflow tube to reseal the trapway, while providing the same amount of water during the long and short flush cycles.
Accordingly, an improved reseal water hose assembly that reduces unnecessary water consumption and assists in the filling of the toilet tank in order to effectuate a more efficient refill cycle is desired. In addition, a trapway reseal assembly that delivers an appropriate volume of reseal water to the trapway regardless of the flush cycle, and which can utilize the excess water flowing from the reseal hose by redirecting this water directly into the tank, is desired.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the present invention, a dual flush device for a toilet tank having a flush valve actuated by a pivotable actuation arm for effecting both a short flush cycle and a long flush cycle, is provided. The dual flush device includes a cam rotatably supported on the toilet tank adjacent the actuation arm. The cam, when rotated in a first direction, acts to press against and pivot the actuation arm to effect the long flush. When the cam is rotated in a second direction, the cam presses against and pivots the actuation arm to effect the short flush. The dual flush device also includes a lever pivotably supported with respect to the actuation arm between a first position out of blocking contact with the actuation arm and a second position where the lever blocks the actuation arm for a predetermined period of time when the cam is rotated in the second direction to hold the actuation arm in a partially raised position. A float is coupled to the lever for determining the predetermined period of time. The float acts to pivot the lever into the second position when the cam is rotated in the second direction.
In a preferred embodiment, the dual flush device includes a single handle for selectively rotating the cam in the first direction and the second direction.
According to another aspect of the present invention, a trapway reseal assembly is provided. A doughnut-shaped float rides along the overflow tube in the toilet tank with the changing water level in the tank. The end of a reseal water hose is supported on the float and selectively directs water into the overflow tube or the tank depending on the height of the float.
Accordingly, it is an object of the present invention to provide an improved toilet flushing device with water saving capabilities.
Another object of the present invention is to provide an improved dual flush device for use in a toilet tank that requires only a single flush valve actuated by a single handle for effecting both a short flush cycle and a long flush cycle.
Yet another object of the present invention is to provide an improved toilet construction that reduces unnecessary water consumption.
Still another object of the present invention is to provide an improved trapway resealing assembly.
Another object of the present invention is to provide an improved trapway resealing assembly for use in toilets with both a long flush cycle and a short flush cycle.
Yet another object of the present invention is to provide an improved trapway resealing assembly that reduces unnecessary water consumption and assists in the filling of the toilet tank in order to effectuate a more efficient refill cycle.
Still another object of the present invention is to provide an improved trapway resealing assembly that delivers an equal quantity of reseal water to the trapway regardless of the flush cycle and utilizes the unnecessary water flowing from the reseal tube by redirecting this water directly into the tank.
A still further object of the present invention is to provide a toilet flushing device with water saving features that can be retrofitted into a conventional toilet tank.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a front elevational view of a toilet with a toilet tank shown partially cut away having a dual flush mechanism and reseal water hose assembly constructed in accordance with a preferred embodiment of the present invention;
FIG. 2 is a top plan view of the toilet and tank of FIG. 1, with the tank cover removed;
FIG. 3 is a rear perspective view of the dual flush mechanism constructed in accordance with a preferred embodiment of the present invention;
FIG. 4 is an exploded perspective view of the dual flush mechanism depicted in FIG. 3;
FIG. 5 is a rear elevational view of the dual flush mechanism in accordance with the present invention, shown prior to the commencement of a flush cycle;
FIG. 6 is a rear elevational view of the dual flush mechanism in accordance with the present invention after the handle has been rotated to commence the long flush cycle;
FIG. 7 is a cross-sectional view taken along lines 7--7 of FIG. 6;
FIG. 8 is a rear elevational view of the dual flush mechanism in accordance with the present invention after the handle has been rotated to commence the short flush cycle;
FIG. 9 is a partial top plan view of the dual flush mechanism of FIG. 8;
FIG. 10 is a top plan view of the reseal water hose assembly constructed in accordance with a preferred embodiment of the present invention; and
FIGS. 11 through 14 depict the reseal water hose operation during the long and short flush cycles in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is first made to FIGS. 1 and 2 of the drawings which depict a toilet, generally indicated at 20, having a toilet bowl 21 and a toilet tank 22. Toilet tank 22 includes a removable tank cover 23. Toilet tank 22 also includes a dual flush mechanism, generally indicated at 30, and a trapway reseal assembly, generally indicated at 50, both constructed in accordance with the present invention.
A water inlet control assembly 70 is provided in the tank for controlling the refilling of toilet tank 22 with fresh water after flushing has occurred. Some fresh water is supplied to a water reseal hose 52 during refilling of the tank. Tank 22 includes an overflow tube 24 which leads to bowl 21 or directly to the toilet trapway below the toilet. Tank 22 also includes a flush valve, generally indicated at 60, which provides a conduit for water to flow from tank 22 to bowl 21 when the toilet is flushed. Flush valve 60 includes a valve seat 62 and a pivotable flush valve flapper 64 which opens and closes the valve.
Reference is now made additionally to FIGS. 3 and 4 to describe the construction of dual flush mechanism 30. Dual flush mechanism 30, as described below in detail, is activated by a handle 32 on the outside of tank 22 which can be rotated in a counterclockwise direction in the direction of arrow A to effectuate a long or full flush cycle and in a clockwise direction in the direction of arrow B to effectuate a short or partial flush cycle.
Dual flush mechanism 30 includes an L-shaped pivotable actuation lever or arm 34 having a first arm 35 and a second arm 36. In a preferred embodiment, first arm 35 is longer than second arm 36. Free end 35a of first arm 35 of actuation lever 34 is coupled to flapper 64 of flush valve 60 through a chain or other flexible linkage 66. Free end 35a of first arm 35 may include several openings 33 spaced therealong to permit fastening of chain 66 thereto at a desired position. A separate flush valve float 67 is attached along chain 66 to hold flapper 64 open during the long flush cycle as described below in detail.
Dual flush mechanism 30 also includes a short flush lever 80 in the form of a pivotable L-shaped bellcrank. A partial flush float 84 is removably coupled to short flush lever 80 through a float rod 86, preferably using a threaded thumb nut 87, although other fastening devices can be used.
As can be seen, dual flush mechanism 30 may be mounted to toilet tank 22, preferably on a front wall thereof. Moreover, the exact position of the mounting can vary within reason, keeping in mind the importance of access to handle 32 and that dual flush mechanism 30 must not be mounted so as to cause interference with pre-existing structure in the conventional tank. In an exemplary embodiment, and as shown in FIG. 3, an opening is formed in the front wall of toilet tank 22 thereby permitting dual flush mechanism 30 to be mounted thereon by positioning the tank wall between a backing plate 38 and a threaded nut or other escutcheon 40. Backing plate 38 includes an opening 38a through which a shaft 31 which rotates with handle 32 extends. However, it is also contemplated that backing plate 38 may be formed as part of the inside wall of the toilet tank itself.
Handle 32 is coupled to dual flush mechanism 30 through shaft 31. A cam 42 in the form of an asymmetrical shoe having a first toe 43 and a second toe 44 is secured to shaft 31 using a screw or the like so as to be rotatable therewith. Cam 42 may be configured in alternate shapes such as a kidney bean shape, so long as cam 42 can operate to contact and lift actuation lever 34 when rotated clockwise and counterclockwise. However, it is noted that other forms of single handle actuation, such as different amounts of rotation, can be used to effectuate the different flush cycles.
In an exemplary embodiment, actuation lever 34 is pivotably supported by a pin 38b extending from backing plate 38. This mounting construction permits actuation lever 34 to be rotatable in a plane essentially parallel to backing plate 38. Arms 35 and 36 of actuation lever 34 may be constructed so as to be rigidly fixed together, or actuation lever 34 may be a unitary member. In addition, arm 35 may also be of a unitary member or may include a joint 78 which permits first arm 35 to be moveable horizontally with respect to second arm 36 to allow for different configurations. A pin 79, screw or the like is mounted as part of joint 78 to secure the sections of actuation lever 34 together.
It is noted that the dual flush mechanism of the present invention works best when free end 35a of arm 35 is positioned at least substantially over flush valve flapper 64. As described in greater detail below, when actuation lever 34 is raised, flush valve flapper 64 is pulled off of flush valve seat 62. Therefore, if free end 35a of arm 35 is positioned above flush valve flapper 64, flushing can be effectuated in a most efficient manner. By providing joint 78, first arm 35 can be rotated about joint 78 to position the free end of arm 35 as desired to avoid interference with other components in the tank.
Short flush lever 80 is pivotably coupled to backing plate 38 through a joint 81 using a dowel, screw or pin 85 or the like. Short flush lever 80 is pivotally coupled to backing plate 38 in a direction transverse to actuation lever 34. Short flush lever 80 includes two legs 82 and 83. Leg 83 is coupled to float rod 86. A partial flush float 84 may be slidably coupled to float rod 86 to permit accommodation in a pre-existing conventional toilet tank and to control the length of the short flush cycle. By permitting partial flush float 84 to be manually repositioned along float rod 86, the dual flush mechanism can be configured to operate in conventional toilets.
In addition, and as particularly shown in FIGS. 4 and 9, float rod 86 can be mounted to leg 83 in various orientations. In this regard, leg 83 has a star-shaped opening 87 to permit an end 86a of float rod 86 to be inserted therein in various positions. End 86a of float rod 86 may include wings 86b and 86c which are accommodated by hole 87. Once positioned, a thumb nut 87a can be used to hold the float rod in place.
A wall stop 90 is provided to prevent the over-rotation of cam 75 as discussed below.
As shown in FIGS. 3 and 5, which depict a pre-flush configuration when the tank is full, leg 82 of short flush lever 80 rests against second arm 36 of actuation lever 34 as float 84 tends to be lifted by the water level in the tank.
Reference is now made to FIGS. 5-7 to describe the operation of the dual flushing mechanism in accordance with the present invention to provide a long or full flush.
Such long or full flush is initiated by rotating handle 32 counterclockwise from the front in the direction of arrow A. This rotation of handle 32 causes shaft 31 to also rotate which in turn causes cam 42 to rotate in the same direction. This rotation causes the long toe 43 of cam 42 to contact an upper portion of second arm 36 of actuation lever 34 thereby raising first arm 35 which in turn pulls on chain 66 to raise flapper 64. Float 67 is accordingly pulled up to the lowering surface of the water W (FIG. 6). The angle through which actuation lever 34 can be rotated and the maximum height reached by arm 35 is limited by wall stop 90. Wall stop 90, shown in an arcuate shape by way of example only and not in a limiting sense, may be mounted to backing plate 38 or be formed integral therewith.
When handle 32 is rotated in the counterclockwise direction of arrow A (when viewed in FIG. 1), short toe 44 of cam 42 contacts the lower edge of wall stop 90 thereby preventing cam 42 and hence handle 32 from rotating any further. In this long or full flush condition, flush valve flapper 64 is shifted to its fully open or buoyant position thereby allowing the water in the tank to empty into the bowl to flush the bowl. As the water level in the tank drops, float 67 also lowers (but remains on the water surface). Actuation lever 34 also lowers to its original position. When the water level drops to a predetermined level, flush valve flapper 64 closes and reseals flush valve seat 62 in the conventional manner, thus terminating the full flush cycle. The tank then begins to refill.
As depicted in FIG. 3, in the pre-flush condition when the tank is full, leg 82 presses against the side of arm 36 of actuation lever 34 due to the buoyancy of flush float 84. As depicted in FIG. 7, when the long flush cycle begins, short flush lever 80 initially rotates towards handle 32 in the direction of arrow C and would appear to prevent actuation lever 34 from returning to its original position after the tank empties. However, it is to be understood that after the long flush cycle begins, the water level in the tank begins to fall as water in the tank is delivered through the flush valve to the bowl. The lowering of the water causes partial flush float 84 to also fall, thereby rotating short flush lever 80 away from handle 32 out of the path of arm 36 of actuation lever 34 before flush valve flapper 64 covers and seals flush valve seat 62. Therefore, it can be seen that the presence of the short flush lever 80 does not affect the long or full flush cycle.
Reference is now made to FIGS. 8-9 which illustrate the operation of the dual flushing mechanism of the present invention during the short flush cycle. A partial or short flush is initiated by rotating handle 32 in the clockwise direction of arrow B (as viewed in FIG. 1). The rotation of handle 32 rotates shaft 31 which causes short toe 44 of cam 42 to contact a lower portion of second arm 36 of actuation lever 34 thereby raising first arm 35 of actuation lever 34 to a second predetermined height, which is less than the predetermined height in the long flush.
The amount of rotation and height is also limited by wall stop 90. In the clockwise direction, toe 43 contacts the top of wall stop 90 to prevent the over-rotation of actuation lever 34. Accordingly, flush valve flapper 64 is not raised off of flush valve seat 62 as high as it is raised during the long full flush cycle operation. Moreover, since float 67 is not raised sufficiently to rise to the water surface, flush valve flapper 64 is held open only due to the tension of chain 66, rather than by the float buoyancy as in the full flush.
As soon as actuation lever 34 is raised, the buoyancy of partial flush float 84 causes leg 82 of short flush lever 80 to rotate towards handle 32 and press against the face of cam 42 as depicted in FIG. 9. When handle 32 is released, leg 82 of short flush lever 80 will contact the inner surface 36a of second arm 36 of actuation lever 34 so as to block further downward movement and maintain first arm 35 of actuation lever 34 in an elevated position allowing flush valve flapper 64 to be held in a partially open position permitting water to flow from the tank to the bowl.
However, after the commencement of the short flush cycle, the water level begins to fall. As the water level falls, partial flush float 84 lowers with the corresponding water level in the tank. At a predetermined water level, the partial flush float 84 will have fallen a sufficient distance to cause short flush lever 80 to rotate back, thus disengaging leg 82 from arm 36 of actuation lever 34, thereby permitting actuation lever 34 to rotate and lower which in turn permits flush valve flapper 64 to close and reseal, thereby terminating the partial or short flush cycle.
As water refills in the tank in the conventional manner, flush float 84 rises in the tank and leg 82 of short flush lever 80 rotates about its pivotal axis to reset itself for the next flush action.
By providing a dual flush mechanism which allows the user to select either a full or partial flush by selected rotation of a single handle to selectively activate a single flush valve, an improved dual flush mechanism that conserves water is provided. A full flush is obtained by the rotation of a single handle in the counterclockwise direction. This rotation causes the cam or shoe to contact an actuation arm, thereby lifting the flush valve from its seat. Upward movement of the actuation arm is limited by a stop.
For a partial flush, the handle is rotated in the clockwise direction. This rotation causes the cam to contact the actuation lever, but raises the actuation lever a lesser amount. Similarly, upward movement of the actuation arm is limited by the stop. Release of the handle allows the short flush lever to temporarily hold the actuation in a partial raised condition, thereby keeping the flush valve in an unseated position allowing water to flow from the tank to the bowl. As the water level in the tank drops, the partial flush float also drops disengaging the short flush lever from the actuation lever. This permits the actuation arm to return to its pre-flush position and reseat the flapper onto the flush valve seat. With the refilling of the tank, the partial flush float rises, rotating the short flush lever to contact the actuation lever in preparation for the next flush cycle.
Reference is now made particularly to FIGS. 10 through 14, which depicts trapway reseal assembly 50. Assembly 50 includes a reseal water hose 52 having a free end 52a which is coupled directly to a reseal float 54. In the preferred embodiment, reseal hose 52 is coupled to reseal float 54 by means of a clip 53 or the like. Reseal float 54 is preferably in the shape of a doughnut and slidably supported to ride along overflow tube 24. Overflow tube 24 may also include a retaining pin 55 (FIG. 10) which prevents reseal float 54 from disengaging from overflow tube 24. In addition, overflow tube 24 may include a splash guard 56 (FIG. 10) to assist in directing water flow from hose 52.
Reference is now made specifically to FIGS. 11 through 14 which illustrate the operation of trapway reseal assembly 50 in accordance with the present invention. In a pre-flush configuration when the tank is full, float 54 is in its uppermost position as shown in FIG. 11. At this position, free end 52a is positioned to direct water in overflow tube 24. However, no water is flowing in the pre-flush condition since the inlet valve of the water control is closed.
After a long or short flush cycle is commenced, as water in the tank empties into the toilet bowl, the reseal float begins to lower with the tank water level. Distance X shown in FIG. 11 shows the distance that the reseal float 54 drops during a short flush cycle, while distance Y show the drop distance for a long flush. Once float 54 drops to the level shown in FIG. 12, reseal hose 52 is below the rim of overflow tube 24 and water from the reseal hose will be directed into the tank.
As the tank refills after the flapper has closed, the reseal float will begin to rise. Water from hose 52 will continue to be directed into the tank until the float hits the level of FIG. 13 where water begins to be directed into the overflow tube. It is specifically noted that the point at which reseal water is first redirected into the overflow tube is the same after either flush cycle, thus ensuring the same quantity of reseal water dedicated to sealing the trapway. As the water continues to rise, reseal hose 52 is again directly over overflow tube 24 so as to cause water to flow directly into overflow tube 24 as shown in FIG. 14. Water will be directed into the overflow tube until the tank is full.
The trapway reseal assembly of the present invention provides for excess water from the reseal hose to be used for refilling the tank. In addition, essentially the same amount of water will be delivered through the overflow tube to the trapway regardless of the length of the flush.
By providing a trapway reseal assembly where the reseal hose is mounted on a float which rides along the overflow tube, an improved dual flushing toilet system that channels an equal volume of reseal water dedicated to sealing the trapway of the toilet is provided. Regardless of the flush cycle, by providing a trapway reseal assembly where water is directed by the position of a reseal float, which itself is positioned by the water level within the tank, an improved reseal assembly is provided.
It will thus be seen that the objects set forth above, and those made apparent from the preceding description are efficiently obtained and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
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A trapway reseal device for a toilet tank where the toilet tank includes an overflow tube and a water control. The trapway reseal device includes a float slidably supported along the overflow tube to move with the changing level of water in the tank as the tank is flushed and refilled. A reseal hose receives water from the water control and includes a free end coupled to the float. The reseal hose selectively directs water into at least one of the tank in the overflow tube dependent upon the position of the float as determined by the level of water in the tank.
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FIELD OF THE INVENTION
[0001] The present invention relates to hydrogel composites and their manufacture, more particularly to composites of hydrogels and fibrous materials having high strength on absorption of water, saline or biological fluids. The invention also relates to such hydrogel composites suitable for use in a variety of applications, such as wound and burns dressings, ostomy devices, biomedical electrodes and other devices where contact with mammalian skin is required.
[0002] The expression “hydrogel” and like expressions, used herein, are not to be considered as limited to gels which contain water, but extend generally to all hydrophilic gels and gel compositions, including those containing organic non-polymeric components in the absence of water.
BACKGROUND OF THE INVENTION
[0003] Hydrogels are macromolecular networks swollen partially or to equilibrium with a suitable fluid, normally an aqueous fluid. It is known that hydrogels are useful in a number of biomedical applications, including but not limited to wound and burns dressings, biomedical electrodes and skin adhesives, particularly because of their ability to donate and absorb fluid and hence maintain a moist but not wet environment.
[0004] There are, however, disadvantages with prior art hydrogel compositions and materials in that they can be weak and difficult to handle particularly when they have absorbed fluid, e.g. the exudate arising from a wound.
[0005] EP-B-0901382, the contents of which are incorporated herein by reference, describes improved reinforced hydrogel compositions based on alginate fibres impregnated with pre-made hydrophilic polymers that are crosslinked by ions released from the fibres. These hydrogels are in a hydrated form and donate moisture to a wound. These materials require the release of cations from the fibre to crosslink the hydrophilic polymer. Hence, the range and scope of materials that may be used for manufacturing these reinforced hydrogels is limited to polymers having pendant carboxylic acid groups.
[0006] It is an object of the present invention to obviate or mitigate the above disadvantages, or at least to provide an acceptable alternative to the prior art systems.
BRIEF DESCRIPTION OF THE INVENTION
[0007] According to a first aspect of the present invention, there is provided a method for producing a hydrogel/fibre composite comprising: impregnating fibres of a fibrous material with a precursor solution comprising at least one polymerisable, and optionally also crosslinkable, monomer such that at least partial swelling of the fibres takes place, and polymerising, and optionally also crosslinking, the at least one monomer after impregnation and a least partial swelling of the fibres such that the integrity of the fibrous material is at least partially preserved in the resulting hydrogel/fibre composite, provided that the crosslinking is not initiated solely by cation release from the fibres of the fibrous material.
[0008] Generally speaking, when crosslinking does not take place, polymeric entanglement will normally take place to provide the necessary properties of the hydrogel/fibre composite.
[0009] According to a second aspect of the present invention, there is provided a hydrogel/fibre composite prepared or preparable by the method of the first aspect of the invention.
[0010] According to a further aspect of the present invention, there is provided a biomedical product comprising the hydrogel/fibre composite of the second aspect of the invention.
[0011] Preferably, the crosslinking, when present, is achieved totally by means other than cation release from fibres of the fibrous material.
[0012] We have found that the present invention can provide hydrogel/fibre composites in which a surprising enhancement of the structural integrity and strength is achieved, particularly when wet (hydrated), in comparison with the hydrogel alone and the fibrous material alone. For example, technical data from the suppliers of the Oasis™ fibrous material used in the Examples described below indicates that this material is not a strong material in comparison with textile fibres. However, when it is used in the hydrogel/fibre composites according to the present invention, a very acceptable strength is achieved. Moreover, the hydrogel/fibre composites in accordance with the invention have been found to be capable of undergoing at least one hydration/dehydration cycle while maintaining very acceptable structural integrity and strength throughout, the main change across the cycle being the dimensions as the swelling and shrinking takes place, with substantial retention of general form and self-supportability of the structure.
[0013] These properties provide the basis for valuable uses of the hydrogel/fibre composites, for example in the manner described below, as a substantial disadvantage of prior art hydrogels has been a loss of structural integrity on hydration or across a hydration/dehydration cycle, leading to disintegration during manufacture, storage, transportation and/or use.
DETAILED DESCRIPTION OF THE INVENTION
[0000] The Fibrous Material
[0014] The fibrous material is preferably a coherent structure comprised of fibres, capable of being swollen by aqueous fluid, that are held together (e.g. by interweaving, entangling, adhesion, compaction, partial melting together or a combination thereof) to maintain overall coherency of the structure. The expression “fibres” includes all elongate forms such as strips, strands and threads. The fibres may be of unitary construction (e.g. by extrusion) or may be composed of a plurality of smaller filaments, which themselves may be secured together in the fibre by any appropriate means, e.g. by intertwining, entangling, spinning, adhesion, partial melting together or a combination thereof. Examples of such structures are knitted, woven and non-woven materials such as felts, mats and the like.
[0015] The fibres may, for example, be biodegradable or bioresorbable, so that they will degrade or be absorbed, over time, in the human or animal body.
[0016] The fibres and/or filaments can be of constant transverse cross-sectional configuration along their length or a portion thereof, or the transverse cross-sectional configuration of the fibres and/or filaments can vary along their length randomly or regularly. The transverse cross-sectional configuration at any particular point along the length of a particular fibre or filament can be any appropriate shape, including square, rectangular, triangular, polygonal, circular, oval, ellipsoidal, irregular, any of the above with indentations, any of the above with projections, or an approximation to any of the above.
[0017] The fibres of the fibrous material are absorbent, so that swelling of the fibrous material includes swelling of individual fibres through uptake of the precursor solution into the fibres.
[0018] Particularly preferred fibrous material structures comprise polymeric fibres capable of swelling in aqueous fluid and have a basis weight of 20 to 300 grams per square metre (gsm), more preferably 20 to 200 gsm and, for wound dressings, more preferably 35 to 180 gsm. The non-impregnated fibrous structure should be capable of absorbing at least 1 g of saline per 1 g of fibre preferably greater than 2 g/g more preferably greater than 5 g/g and even more preferably greater than 10 g/g.
[0019] The polymeric fibres may be natural, synthetic or any combination thereof. Particularly preferred types of fibre comprise calcium alginate (available from, for example, Acordis Speciality Fibres), carboxymethyl cellulose fibres (available from, for example, Acordis Speciality Fibres), Sodium Polyacrylate (available, for example, under the tradename Oasis™ from Acordis, Technical Absorbents Limited).
[0020] The fibrous material structure may be in the form of a continuous sheet or perforated. The perforations may be of any shape, for example—but not limited to, circular, square, rectangular, triangular, polygonal, circular, oval, ellipsoidal, irregular, any of the above with indentations, any of the above with projections, or an approximation to any of the above. The side walls of the perforations may be tapered in a straight way, tapered in a curved way, untapered, or any combination thereof at different points along their length. The perforations may include regions along their lengths which define enlarged cavities within the fibrous material structure. The perforations may be interconnected within the fibrous material structure, and such interconnections may comprise passages which may, for example, have tapering side walls which taper in a straight way, tapering side walls which taper in a curved way, untapered side walls, side walls which define enlarged cavities within the fibrous material structure, or any combination thereof at different points along their length.
[0021] The size and frequency of the perforations maybe varied according to requirements, aesthetic and functional. The transverse cross-sectional area of each perforation as appearing at the surface of the fibrous material may suitably be less than about 9 cm 2 , for example less than about 7 cm 2 , for example less than about 4 cm 2 , for example less than about 1 cm 2 .
[0022] The perforations may be provided in a regular array across the fibrous material, or may be irregularly provided, or at least one region of perforations may be regular and at least one other region may be irregular. The perforations may define indicia, for example letters, numbers, shapes, logos
[0000] The Precursor Solution and Polymerisation Method
[0023] Preferably, the precursor solution is aqueous. The precursor solution may comprise aqueous solutions of one or more monomers that are ionic, non ionic, amphoteric, zwitterionic or combinations thereof.
[0024] The precursor solution preferably contains one or more monomers capable on polymerisation of forming a three-dimensional matrix of cross-linked polymer molecules.
[0025] The expressions “polymer”, “polymerisation” and like expressions, used herein, includes within its scope homopolymerisation and copolymerisation and the products thereof.
[0026] Examples of suitable monomers for use in the present invention include: 2-acrylamido-2-methylpropane sulphonic acid or a substituted derivative thereof or a salt thereof (e.g. an ammonium or alkali metal salt such as sodium, potassium or lithium salts); acrylic acid or a substituted derivative thereof or a salt thereof (e.g. an alkali metal salt such as sodium, potassium or lithium salt); a polyalkylene glycol acrylate or a substituted derivative thereof; a polyalkylene glycol methacrylate or a substituted derivative thereof; acrylic acid (3-sulphopropyl) ester or a substituted derivative thereof or a salt thereof (e.g. an alkali metal salt such as sodium, potassium or lithium salt); diacetone acrylamide (N-1,1-dimethyl-3-oxobutyl-acrylamide); a vinyl lactam (e.g. N-vinyl pyrrolidone or a substituted derivative thereof); an optionally substituted N-alkylated acrylamide such as hydroxyethyl acrylamide; and an optionally substituted N,N-dialkylated acrylamide; and/or N-acryloyl morpholine or a substituted derivative thereof.
[0027] The hydrogel used in the present invention preferably comprises a plasticised three-dimensional matrix of cross-linked polymer molecules, and has sufficient structural integrity to be self-supporting even at very high levels of internal water content, with sufficient flexibility to conform to the surface contours of mammalian skin or other surface with which it is in contact.
[0028] The hydrogel generally comprises, in addition to the cross-linked polymeric network, an aqueous or non-aqueous plasticising medium including an organic plasticiser. This plasticising medium is preferably present in the same precursor solution as the monomer(s), although if desired it may be applied to the fibrous material separately from the monomer(s) but before polymerisation.
[0029] The fibrous material in contact with the precursor solution may suitably be in the form of a layer. This layer may suitably be provided for the polymerisation on a surface, most preferably itself provided with a release layer such as siliconised paper of plastic. After polymerisation of such an arrangement, the resultant hydrogel/fibrous composite will be in the form of a sheet having its underside protected by the release layer.
[0030] In the material to be polymerised, the precursor solution preferably comprises the monomer(s), cross-linking agent, plasticiser, and optionally water and other ingredients as desired. The polymerisation reaction is preferably a free-radical polymerisation with cross-linking, which may for example be induced by light, heat, radiation (e.g. ionising radiation), or redox catalysts, as is well known.
[0031] For example, the free radical polymerisation may be initiated in known manner by light (photoinitiation), particularly ultraviolet light (UV photoinitiation); heat (thermal initiation); electron beam (e-beam initiation); ionising radiation, particularly gamma radiation (gamma initiation); non-ionising radiation, particularly microwave radiation (microwave initiation); or any combination thereof. The precursor solution may include appropriate substances (initiators), at appropriate levels, e.g. up to about 5% by weight, more particularly between about 0.002% and about 2% by weight, which serve to assist the polymerisation and its initiation, in generally known manner.
[0032] Preferred photoinitiators include any of the following either alone or in combination:
[0033] Type I-α-hydroxy-ketones and benzilidimethyl-ketals e.g. Irgacure 651. These are believed on irradiation to form benzoyl radicals that initiate polymerisation. Photoinitiators of this type that are preferred are those that do not carry substituents in the para position of the aromatic ring. Examples include Irgacure184 and Daracur 1173 (alternatively: Darocur 1173 or Daracure 1173) as marketed by Ciba Chemicals, as well as combinations thereof.
[0034] A particularly preferred photoinitiator is 1-hydroxycyclohexyl phenyl ketone; for example, as marketed under the trade name Irgacure 184 by Ciba Speciality Chemicals. Also preferred are Daracur 1173 (2-hydroxy-2-propyl phenyl ketone) and mixtures of Irgacure 184 and Daracur 1173.
[0035] Photo-polymerisation is particularly suitable, and may be achieved using light, optionally together with other initiators, such as heat and/or ionizing radiation. Photoinitiation will usually be applied by subjecting the pre-gel reaction mixture containing an appropriate photoinitiation agent to ultraviolet (UV) light. The incident UV intensity, at a wavelength in the range from 240 to 420 nm, is typically greater than about 10 mW/cm 2 . The processing will generally be carried out in a controlled manner involving a precise predetermined sequence of mixing and thermal treatment or history.
[0036] The UV irradiation time scale should ideally be less than 60 seconds, and preferably less than 10 seconds to form a gel with better than 95% conversion of the monomers. Those skilled in the art will appreciate that the extent of irradiation will be dependent on a number of factors, including the UV intensity, the type of UV source used, the photoinitiator quantum yield, the amount of monomer(s) present, the nature of the monomer(s) present and the presence of polymerisation inhibitor.
[0037] In one preferred embodiment, (on the one hand) the precursor solution in contact with the fibrous material and (on the other hand) the source of the polymerisation initiator (e.g. the radiation source) may move relative to one another for the polymerisation step. In this way, a relatively large amount of polymerisable material can be polymerised in one procedure, more than could be handled in a static system. This moving, or continuous, production system is preferred.
[0038] After completion of the polymerisation, the hydrogel/fibrous composite is preferably sterilised in conventional manner. The sterile composite may be used immediately, e.g. to provide a skin-adhesive layer in an article, or a top release layer may be applied to the composite for storage and transportation of the composite.
[0039] If desired, certain ingredients of the hydrogel may be added after the polymerisation and optional cross-linking reaction. However, it is generally preferred that substantially all of the final ingredients of the hydrogel are present in the precursor solution, and that—apart from minor conventional conditioning or, in some cases, subsequent modifications caused by the sterilisation procedure—substantially no chemical modification of the hydrogel takes place after completion of the polymerisation reaction.
[0040] Monomers
[0041] Optional substituents of the monomers used to prepare the hydrogels used in the present invention may preferably to selected from substituents which are known in the art or are reasonably expected to provide polymerisable monomers which form hydrogel polymers having the properties necessary for the present invention. Suitable substituents include, for example, lower alkyl, hydroxy, halo and amino groups.
[0042] Particularly preferred monomers include: the sodium salt of 2-acrylamido-2-methylpropane sulphonic acid, commonly known as NaAMPS, which is available commercially at present from Lubrizol as either a 50% aqueous solution (reference code LZ2405) or a 58% aqueous solution (reference code LZ2405A); acrylic acid (3-sulphopropyl) ester potassium salt, commonly known as SPA or SPAK (SPA or SPAK is available commercially in the form of a pure solid from Raschig); N-acryloyl morpholine; and hydroxyethyl acrylamide.
[0043] Cross-Linking Agents
[0044] Conventional cross-linking agents are suitably used to provide the necessary mechanical stability and to control the adhesive properties of the hydrogel. The amount of cross-linking agent required will be readily apparent to those skilled in the art such as from about 0.01% to about 0.5%, particularly from about 0.05% to about 0.4%, most particularly from about 0.08% to about 0.3%, by weight of the total polymerisation reaction mixture. Typical cross-linkers include tripropylene glycol diacrylate, ethylene glycol dimethacrylate, triacrylate, polyethylene glycol diacrylate (polyethylene glycol (PEG) molecular weight between about 100 and about 4000, for example PEG400 or PEG600), and methylene bis acrylamide.
[0045] Organic Plasticisers
[0046] The one or more organic plasticiser, when present, may suitably comprise any of the following either alone or in combination: at least one polyhydric alcohol (such as glycerol, polyethylene glycol, or sorbitol), at least one ester derived therefrom, at least one polymeric alcohol (such as polyethylene oxide) and/or at least one mono- or poly-alkylated derivative of a polyhydric or polymeric alcohol (such as alkylated polyethylene glycol). Glycerol is the preferred plasticiser. An alternative preferred plasticiser is the ester derived from boric acid and glycerol. When present, the organic plasticiser may comprise up to about 45% by weight of the hydrogel composition.
[0047] Surfactants
[0048] Any compatible surfactant may optionally be used as an additional ingredient of the hydrogel composition. Surfactants can lower the surface tension of the mixture before polymerisation and thus aid processing. The surfactant or surfactants may be non-ionic, anionic, zwitterionic or cationic, alone or in any mixture or combination. The surfactant may itself be reactive, i.e. capable of participating in the hydrogel-forming reaction. The total amount of surfactant, if present, is suitably up to about 10% by weight of the hydrogel composition, preferably from about 0.05% to about 4% by weight.
[0049] In a preferred embodiment of the invention the surfactant comprises at least one propylene oxide/ethylene oxide block copolymer, for example such as that supplied by BASF Plc under the trade name Pluronic P65 or L64.
[0050] Other Additives
[0051] The hydrogel in the composite of the present invention may include one or more additional ingredients, which may be added to the pre-polymerisation mixture or the polymerised product, at the choice of the skilled worker. Such additional ingredients are selected from additives known in the art, including, for example, water, organic plasticisers, surfactants, polymeric material (hydrophobic or hydrophilic in nature, including proteins, enzymes, naturally occurring polymers and gums), synthetic polymers with and without pendant carboxylic acids, electrolytes, pH regulators, colorants, chloride sources, bioactive compounds and mixtures thereof. The polymers can be natural polymers (e.g. xanthan gum), synthetic polymers (e.g. polyoxypropylene-polyoxyethylene block copolymer or poly-(methyl vinyl ether alt maleic anhydride)), or any combination thereof. By “bioactive compounds” we mean any compound or mixture included within the hydrogel for some effect it has on living systems, whether the living system be bacteria or other microorganisms or higher animals such as the patient. Bioactive compounds that may be mentioned include, for example, pharmaceutically active compounds, antimicrobial agents, antiseptic agents, antibiotics and any combination thereof. Antimicrobial agents may, for example, include: sources of oxygen and/or iodine (e.g. hydrogen peroxide or a source thereof and/or an iodide salt such as potassium iodide) (see, for example Bioxzyme™ technology, for example in The Sunday Telegraph (UK) 26 Jan. 2003 or the discussion of the Oxyzyme™ system at www.wounds-uk.com/posterabstracts2003.pdf); honey (e.g. active Manuka honey); antimicrobial metals, metal ions and salts, such as, for example, silver-containing antimicrobial agents (e.g. colloidal silver, silver oxide, silver nitrate, silver thiosulphate, silver sulphadiazine, or any combination thereof); or any combination thereof.
[0052] In the Bioxzyme system, a dressing comprises two hydrogels. One contains glucose based antibacterial compounds and the other contains enzymes that convert the glucose into hydrogen peroxide. When these are exposed to air and contacted together at a wound site, the enzyme-containing gel adjacent the skin and the glucose-containing gel overlying the enzyme-containing gel, a low level steady flow of hydrogen peroxide is produced, which inhibits anaerobic bacteria. This antibacterial effect can be enhanced by the inclusion of a very low level of iodide (less than about 0.04%) in the hydrogel. The hydrogen peroxide and the iodide react to produce iodine, a potent antimicrobial agent.
[0053] Hydrogels incorporating antimicrobial agents may, for example, be active against such organisms as Staphylococcus aureus and Pseudomonas aeruginosa.
[0054] Agents for stimulating the healing of wounds and/or for restricting or preventing scarring may be incorporated into the hydrogel. Examples of such agents include growth factors e.g. from GroPep Ltd, Australia or Procyte, USA (see, e.g. WO-A-96/02270, the contents of which are incorporated herein by reference); cell nutrients (see, e.g., WO-A-93/04691, the contents of which are incorporated herein by reference); glucose (see, e.g., WO-A-93/10795, the contents of which are incorporated herein by reference); an anabolic hormone or hormone mixture such as insulin, triiodothyronine, thyroxine or any combination thereof (see, e.g., WO-A-93/04691, the contents of which are incorporated herein by reference); or any combination thereof.
[0055] Additional polymer(s), typically rheology modifying polymer(s), may be incorporated into the polymerisation reaction mixture at levels typically up to about 10% by weight of total polymerisation reaction mixture, e.g. from about 0.2% to about 10% by weight. Such polymer(s) may include polyacrylamide, poly-NaAMPS, polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) or carboxymethyl cellulose.
[0056] The hydrogel in the composite of the present invention preferably consists essentially of a cross-linked hydrophilic polymer of a hydrophilic monomer and optionally one or more comonomer, together with water and/or one or more organic plasticiser, and optionally together with one or more additives selected from surfactants, polymers, pH regulators, electrolytes, chloride sources, bioactive compounds and mixtures thereof, with less than about 10% by weight of other additives.
[0057] For further details of the hydrogel material for use in the present invention, and its preparation, please refer to the following publications: PCT Patent Applications Nos. WO-97/24149, WO-97/34947, WO-00/06214, WO-00/06215, WO-00/07638, WO-00/46319, WO-00/65143 and WO-01/96422, the disclosures of which are incorporated herein by reference.
[0058] The water activity, which is related to the osmolarity and the ionic strength of the precursor solution (as measured, for example, by a chilled mirror dewpoint meter, Aqualab T3) is preferably between 0.05 and 0.99, more preferably between, 0.2 and 0.99, and even more preferably between 0.3 and 0.98. The higher the ionic strength, reflected in a lower water activity, the lesser the swelling of the fibre structure. The ionic strength of the precursor solution can therefore be used to optimise the hydrogel composite properties.
[0000] Impregnation of the Fibrous Material
[0059] Preferably, the polymerising and crosslinking of the at least one monomer takes place after completion of the at least partial swelling of the fibrous material.
[0060] The impregnation of the fibre structure may be achieved for example by dipping the fibre structure into a bath of solution or by dispensing the solution from, for example, a slot die onto the fibre structure.
[0061] Alternatively, the precursor solution may be dispensed onto a substrate and the fibre structure placed on top, using the absorbency characteristics of the fibre to take up the precursor solution.
[0062] The length of time between impregnating the fibre and curing (polymerising and optionally crosslinking) the composite may be varied to allow control over the extent of fibre swelling and resultant properties for example fluid uptake and strength of the swollen composite. Preferably, the length of time the precursor solution is in contact with the fibre before curing is between 0.5 and 45 seconds, more preferably between 1 and 20 seconds.
[0063] The ratio of fibre to precursor solution is from 1:1 to 1:30, preferably 1:2 to 1:20, more preferably 1:3 to 1:18 and even more preferably from 1:4 to 1:14 as determined by the weight of fibre per square meter and the amount (weight) of precursor solution incorporated per square meter.
[0064] The nature and extent of impregnation of the fibrous material by the precursor solution can thus be varied extensively according to the desired characteristics of the final composite material. For example, there can be a gradient, which can be linear or non-linear or part-linear-part-non-linear, of the amount (e.g. by weight) of the precursor solution taken up per unit volume of fibrous material, according to the distance into the bulk of the fibrous material. That gradient will be such that, at any particular region or regions within the fibrous material, the amount of precursor solution per unit volume of fibrous material increases or decreases with distance into the bulk of the fibrous material. Alternatively, regions or the whole of the bulk of the fibrous material may be impregnated in such a way that there is a uniform or substantially uniform distribution of the precursor solution through the relevant portion or whole of the bulk of the fibrous material.
[0000] Articles and Applications
[0065] The hydrogels present in the composites described herein may be adhesive or non-adhesive. When they are adhesive, they are typically tacky to the touch, and therefore lend themselves to applications where a certain degree of adhesion to mammalian (particularly human) skin is required. When the hydrogel composites described herein are non-adhesive, they typically have no or negligible tackiness to the touch.
[0066] Adhesive hydrogel composites according to the present invention may preferably be capable of being removed from the skin without undue pain, discomfort or irritation, and without leaving a substantial mark or residue on the skin.
[0067] The composites may thus suitably be used in a range of skin contact or covering articles and applications where the composite is brought into contact either with skin or with an intermediary member which interfaces between the composite and the skin. The composite may be unsupported or may be supported on a part of a larger article for some specific use, e.g. a backing structure. The composites may suitably be in the form of sheets, coatings, membranes or laminates.
[0068] Articles and applications include patches, tapes, bandages, devices and dressings of general utility or for specific uses, including without limitation biomedical, skin care, personal and body care, palliative and veterinary uses such as, for example, skin electrodes for diagnostic (e.g. ECG), stimulation (e.g. TENS), therapeutic (e.g. defibrillation) or electrosurgical (e.g. electrocauterisation) use; dressings and reservoirs for assisting wound and burn healing, wound and burn management, skin cooling, skin moisturizing, skin warming, aroma release or delivery, decongestant release or delivery, pharmaceutical and drug release or delivery, perfume release or delivery, fragrance release or delivery, scent release or delivery, and other skin contacting devices such as absorbent pads or patches for absorbing body fluids (e.g. lactation pads for nursing mothers), cosmetic device adhesives, hairpiece adhesives and clothing adhesives; and adhesive flanges and tabs for fecal collection receptacles, ostomy devices and other incontinence devices.
[0069] The articles incorporating the hydrogel composites according to the present invention may have any convenient shape or configuration. Particularly but not exclusively, the articles may be provided in any conventional shape or configuration for the category of articles concerned, or any approximation thereto. For example, articles in substantially sheet form may be square, rectangular, triangular, polygonal, circular, oval, ellipsoidal, irregular, any of the above with indentations, any of the above with projections, or an approximation to any of the above.
[0070] The articles incorporating the hydrogel composites according to the present invention may incorporate the said composite as an island surrounded by other portions of that or those face(s) of the article of which the hydrogel composite forms part, or the said composite may extend to one or more edge of such face(s). Where the hydrogel composite is an island surrounded by other portions of that or those face(s) of the article of which the hydrogel composite forms part, the surrounding portions may be provided with other adhesive materials such as conventional pressure sensitive adhesives, such as, for example, acrylate ester adhesives, e.g. to provide skin adhesion.
[0071] Articles such as, for example, patches, tapes, bandages, devices, dressings of general utility or for specific uses, including without limitation biomedical, skin care, personal and body care, palliative and veterinary uses such as, for example, skin electrodes for diagnostic (e.g. ECG), stimulation (e.g. TENS), therapeutic (e.g. defibrillation) or electrosurgical (e.g. electrocauterisation) use; dressings and reservoirs for assisting wound and burn healing, wound and burn management, skin cooling, skin moisturizing, skin warming, aroma release or delivery, decongestant release or delivery, pharmaceutical and drug release or delivery, perfume release or delivery, fragrance release or delivery, scent release or delivery, and other skin contacting devices such as absorbent pads or patches for absorbing body fluids (e.g. lactation pads for nursing mothers), cosmetic device adhesives, hairpiece adhesives and clothing adhesives; and adhesive flanges and tabs for fecal collection receptacles, ostomy devices and other incontinence devices may suitably comprise a support member, typically in sheet or substantially sheet form, which is suitably flexible, conformable to the skin, with which the hydrogel composite according to the present invention is associated. The support member may be perforated or non-perforated. The support member may be unitary in construction or constructed as a composite of multiple parts, e.g. a plurality of layers. The construction of the parts other than the hydrogel composite of the present invention may suitably be generally conventional. For example, the support member of a wound dressing or the like may suitably comprise a flexible water-permeable or water-impermeable backing layer or other structure, which may optionally incorporate other adhesives if desired, and/or an absorbent layer or other structure (e.g. a foam or other absorbent material). Such additional parts may suitably be formed in any suitable material conventionally used for such articles, including for example synthetic and natural materials, e.g. polymers such as polyurethane, polyolefins, hydrogels, or any combination thereof.
[0072] Articles comprising multiple parts—e.g. layers or sheets—may suitably include adhesives (e.g. acrylic adhesives) to bond the parts together, or the parts may be retained together in the article by partial melting together, by crimping, embossing or other mechanical retention method, or any combination thereof.
[0073] If desired, a part of an article or a complete article, such as a skin patch, wound or burn dressing, bandage or plaster can incorporate a system for generating an bioactive agent such as a pharmaceutically active agent or combination of agents (drug), an antimicrobial agent or combination of agents, an antiseptic agent or combination of agents, or an antibiotic agent or combination of agents. Such a system may, for example, be the Bioxzyme™ system mentioned above.
[0074] Parts of the articles which are adapted to contact a patient during use, and at least those portions of the article adjacent to the patient-contacting parts, may if desired be sterilised and may conveniently be stored in sterile packaging.
[0075] The hydrogel composites according to the present invention, and articles incorporating them, are suitably provided for storage, transportation and before use with a release sheet overlying any adhesive portions. The release sheet may take any conventional form, e.g. a paper or plastics sheet which may suitably be coated with a non-stick material such as silicone or polytetrafluoroethylene.
[0076] If desired, other portions of the articles may also suitably be provided for storage, transportation and before use with a release sheet overlying any other portions. The release sheet may take any conventional form, e.g. a paper or plastics sheet which may suitably be coated with a non-stick material such as silicone or polytetrafluoroethylene. For example, a surface of an article such as skin dressing which in use is directed away from the wearer's skin may if desired be provided with a surface or surface material that benefits from protection before use. In that case, for example, the said surface or surface material can be protected for storage and transportation before use by the release layer, which can then be removed and discarded after the article has been applied to the wearer's skin.
EXAMPLES
[0077] The following non-limiting examples are provided as further illustration of the present invention, but without limitation.
Example 1
[0078] A 10 cm 2 sample of Oasis™ 180 gsm polyacrylate fibre was immersed into a bath of precursor solution comprising 70 parts by weight of 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulphonic acid (Na AMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 secs. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The ratio of fibre to precursor solution by weight was 1:11. The resulting composite had a saline absorbency of ca. 6 g/g over 24 hours and had excellent strength.
Example 2
[0079] A 10 cm 2 sample of Oasis™ 70 gsm polyacrylate fibre was immersed into a bath of precursor solution comprising 70 parts by weight of 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulphonic acid (Na AMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 secs. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The ratio of fibre to precursor solution by weight was 1:5. The resulting composite had a saline absorbency of ca. 12 g/g over 24 hours and had good strength.
Example 3
[0080] A 10 cm 2 sample of Oasis™ 120 gsm polyacrylate fibre was immersed into a bath of precursor solution comprising 70 parts by weight of 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulphonic acid (Na AMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 secs. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The ratio of fibre to precursor solution by weight was 1:11. The resulting composite had a saline absorbency of ca. 6 g/g over 24 hours and had excellent strength.
Example 4
[0081] A 10 cm 2 sample of carboxymethyl cellulose, 100 gsm fibre (Acordis Speciality Fibres) was immersed into a bath of precursor solution comprising 70 parts by weight of 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulphonic acid (NaAMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 secs. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The resulting composite had a saline absorbency of ca. 8 g/g over 24 hours and had excellent strength.
Example 5
[0082] A 10 cm 2 sample of calcium alginate, 100 gsm fibre (Acordis Speciality Fibres) was immersed into a bath of precursor solution comprising 70 parts by weight of 58% aqueous solution of the Sodium salt of acrylamidomethylpropanesulphonic acid (NaAMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 secs. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The resulting composite had a saline absorbency of ca. 10 g/g over 24 hours and had excellent strength.
Example 6
[0083] A 10 cm 2 sample of Oasis™ 180 gsm fibre (Acordis Speciality Fibres) was perforated with a flat bed die such that the holes were ca. 7 mm in diameter and separated from edge to edge by 5 mm was immersed into a bath of precursor solution comprising 70 parts by weight of 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulphonic acid (Na AMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 secs. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The resulting composite had a saline absorbency of ca. 6 g/g over 24 hours and had excellent strength.
Example 7
[0084] A 10 cm 2 sample of calcium alginate, 100 gsm fibre (Acordis Speciality Fibres) was immersed into a bath of precursor solution comprising 52 parts by weight of 58% aqueous solution of the sodium salt of acrylamidomethyl-propanesulphonic acid (NaAMPS, LZ2405 Lubrizol), 48 parts water and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 secs. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The resulting composite had a saline absorbency of ca. 10 g/g over 24 hours and had excellent strength.
Example 8
[0085] A precursor solution comprising 70 parts by weight of 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulphonic acid (NaAMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals) was dispensed from a slot die 120 mm wide at a coat weight of 1.4 kg/sqm onto a moving web of siliconised polyester film. A 10 cm 2 sample of Oasis™ 180 gsm fibre (Acordis Speciality Fibres) was placed on top and remained in contact for 15 seconds before being cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The resulting composite had a saline absorbency of ca. 6 g/g over 24 hours and had excellent strength.
Example 9
[0086] A 10 cm 2 sample of Lantor 46.09.049, cellulose/polyolefin-based, alginate-containing non-woven was perforated with a flat bed die such that the holes were about 7 mm in diameter and separated from edge to edge by 5 mm was immersed into a bath of precursor solution comprising 70 parts by weight of a 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulphonic acid (Na AMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 seconds. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The resulting composite had good saline absorbency over 24 hours and had excellent strength.
Example 10
[0087] A 10 cm 2 sample of Lantor 71.01.6 Oasis™/polyester-based non-woven was perforated with a flat bed die such that the holes were about 7 mm in diameter and separated from edge to edge by 5 mm was immersed into a bath of precursor solution comprising 70 parts by weight of 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulphonic acid (Na AMPS, LZ2405 Lubrizol), 30 parts glycerol and 0.14 parts of a 1 to 10 (by weight) mixture of Daracure 1173 photoinitiator (Ciba Speciality Chemicals) and IRR280 cross-linker (PEG400 diacrylate, UCB Chemicals). The time of immersion was approximately 2 secs. The impregnated structure was then placed on a conveyor belt moving at 7 m/s and cured with a NUVA Solo 30 medium pressure mercury arc lamp (GEW). The resulting composite had good saline absorbency over 24 hours and had excellent strength.
[0088] The above broadly describes the present invention, without limitation. Variations and modifications as will be readily apparent to those of ordinary skill in this art are intended to be covered by this application and all subsequent patents.
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A method for producing a hydrogel/fibre composite comprises: impregnating fibres of a fibrous material with a precursor solution comprising at least one polymerisable, and optionally also crosslinkable, monomer such that at least partial swelling of the fibres takes place; and polymerising, and optionally also crosslinking, the at least one monomer after impregnation and at least partial swelling of the fibres such that the integrity of the fibrous material is at least partially preserved in the resulting hydrogel/fibre composite, provided that the crosslinking is not initiated solely by cation release from the fibres of the fibrous material. The invention provides a hydrogel/fibre composite prepared or preparable by the said method. The hydrogel/fibre composite may be adhesive to human skin with good properties of performance and subsequent painless removal. The composite is found to maintain acceptable strength and structural integrity on hydration or across one or more hydration/dehydration cycle, and thus finds use in, for example, biomedical products where this property is required.
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FIELD OF APPLICATION
The present invention relates to a single-wafer heat-treatment apparatus comprising a reactor vessel having a ceiling portion and a side portion, and a heater or heaters installed outside or inside the reactor vessel, whereby a single wafer is disposed at a predetermined position in the vessel for heat-treatment. The wafer processing may be an under-vacuum film-formation on a wafer, diffusion in a wafer, or chemical treatment such as CVD treatment of a wafer. Furthermore the invention relates to a method of manufacturing a reactor vessel for the apparatus.
PRIOR ART
Up to now, under-vacuum film-formation on a wafer, diffusion in a wafer, or chemical treatment such as CVD treatment of a wafer has been conducted in a so-called batchwise treatment mode with a plurality of wafers which are held in a boat and transferred into a reactor vessel.
In such a treatment mode, turbulence of a gas stream produced in the neighborhood of a contacting spot between a wafer and the boat and turbulence of a gas stream flowing in a space between adjacent wafers stacked one above the another both interfere with uniform treatment of all wafers in a batch.
In the recent trend of increase in the diameter of a wafer from 6 inches to 8 inches and further up to 12 inches, there arise difficulty manufacturing a boat and supporting details thereof compatible with increase in weight of a wafer, for processing is conducted in the batchwise treatment mode. In addition, enlargement of a reactor vessel corresponding to the increase in the diameter causes lack of uniformity of both temperature distribution in heating and of gas dispersion, which is accompanied by needless increase in power for heating.
In a process of fabrication of a semiconductor device with a higher packing density such as 64 M IC of the next generation, processing accuracy within a sub-micron scale is required. There is, however, unavoidable difficulty in attaining such a high accuracy in a conventional batchwise processing mode, since the upper side and lower side of a wafer stacked in a boat is not subject to uniform treatment conditions. It is also the case that between gas flowing-in and gas exhaust, adjacent wafers are influenced differently, and further particles are produced at a contacting spot between a wafer and the boat.
In order to eliminate such faults and to cope with the recent trends toward a larger diameter of a wafer, and a higher packed density and higher quality of a semiconductor device in the next generation, single-wafer heat-treatment apparatuses in which heat-treatment is conducted on a single wafer in each processing are drawing attention.
The single-wafer heat-treatment apparatuses are divided into the two categories, one of which is to install a heater or heaters within a reactor vessel and the other is to position the heater or heaters outside the reactor vessel.
FIG. 1 shows an example of the apparatus which has a heater inside, which is disclosed in a book entitled "Super LSI Fabrication Testing Apparatus Guide Book" published by Kogyo Chosakai, in Table 5 of page 58. The apparatus of the example comprises a stainless chamber 101 as a reactor vessel, a wafer 103 disposed in the spatial center thereof by means of a susceptor 102, a heater 104 above the wafer 103, a gas nozzle 105 under the wafer 103, a water-cooled shroud 106 surrounding the nozzle 105, and a vacuum pump 107.
On the other hand, as an external-heater type apparatus, some are disclosed in Table 3 of page 56 of the aforementioned Guide Book. FIG. 2 shows an apparatus for heating a wafer from above, in which a quartz glass window 112 is attached in a sealing condition to an upper opening of a stainless vessel 111 which accommodates a wafer 110, heater lamps 113 and a housing 114 therefor are installed above the quartz glass window 112. The wafer 110 is heated through the quartz glass window 112, where a gas inlet 115 feeds gas to a distributor plate 116 and a channel 117 for an exhaust gas communicates with a vacuum pump.
In the former internal-heater type apparatus, a water-cooled shroud is installed as a heat shield between the vessel and a heated region, and from that a problem arises in regard to uniform distribution of heating.
On the other hand, even in the latter external-heater type apparatus, in order to prevent heat deterioration of an O-ring lying between the quartz glass window 112 and a sealing portion 112a at the upper end of the stainless vessel 111, the portion in the vicinity of the sealing portion 112a is required to be water-cooled. The problems of uniform distribution of heating and complication of structure therefore remain.
In either technique, complication of the structures is unavoidable due to necessary water-cooling of a greater part of the apparatuses. A problem arises in holding a degree of air-tightness, since the junction between the heat-transparent material and the water-cooled material is unavoidably positioned close to the heat-receiving portion, and besides another problem is brought about in relation to adopting the stainless vessel as a reactor vessel.
In light of the above-mentioned circumstances, a study is conducted about a vessel all composed of transparent quartz glass similar to a conventional furnace tube as an alternative of the above-mentioned reactors. For example, a reactor vessel is proposed which comprises an end cover and a lower vessel in Table 3 of page 56 of the aforementioned Guide Book, which also has a problem that an O ring at a sealing portion is subject to deterioration, since the O-ring is required for sealing when the vessel is thus divided into two parts. Therefore, a single-wafer heat-treatment apparatus, too, is studied that has shapes approximating a dome or a cylinder at an end of which an end cover shaped as a flat plate or a hemisphere is welded, similarly to the shape of a conventional vertical furnace tube.
In the past, a wafer was generally smaller than 6 inches in diameter and a reactor tube was manufactured by a welding technique. For wafers 8 inches or 12 inches in diameter the reactor vessel has to be enlarged, but it is difficult to weld such a large reactor vessel having sufficient mechanical strength.
What is more, a quartz glass reactor vessel is manufactured with transparency in order to be able to receive heat from the outside. To manufacture it all with such transparency requires heating a wider portion in the reactor vessel than necessary for heating a wafer. As a result, unnecessary reactions in the vessel or unfavorable influences on facilities in the neighborhood around the vessel take place.
Using transparent quartz glass as a structure material means good heat conduction and therefore the sealing flange has to be remote from the heating region, so that the reactor vessel unavoidably becomes larger in diameter and thus also larger in height in order to have the sealing portion far enough from the heated region.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a heat-treatment apparatus which secures enough mechanical strength of its own and uniformly heats a wafer even when the reactor vessel is enlarged to accommodate a wafer with a diameter of 8 to 12 inches.
It is another object of the present invention to provide a heat-treatment apparatus that secures both a heat insulation effect and uniform heating effect of a heated region of a wafer, prevents any portion of the vessel for which heating is unnecessary from being heated, effectively stops unnecessary reactions, and prevents a sealing portion and neighboring facilities being unfavorably affected.
It is a further object of the present invention to improve efficiency in loading and unloading wafers.
What is featured by the present invention is that the reactor vessel is substantially a single body, at least a heated region of the reactor vessel includes no welded portion, and at least a part of the heated region is translucent or opaque by bubbles distributed almost throughout the bulk of the region.
In a first preferred embodiment of the invention, which is applicable to both external-heater type or internal-heater type wafer heat-treatment apparatus, the former of which has a heater or heaters outside the reactor vessel and the latter of which has the heater or the heaters inside the reactor vessel, almost all of the heated region or heated regions contain enough bubbles therein as to be translucent or opaque.
The reactor vessel is generally shaped as approximation of a hemisphere, a dome, or a cylinder and preferably it all is composed as a single body except a flange portion.
It is necessary that the circular opening of the lower end of the reactor vessel later may join a flange by welding along the outer periphery, but the heated region and the ceiling of the vessel is composed substantially as a single body with no welded portion therein.
The translucent or opaque portion is not necessarily limited to the heated region and all the vessel may be translucent or opaque. A transparent window for observing a state of heat-treatment of a wafer may be arranged in a position where the window does not affect heat-treatment of a wafer in the heated region of the vessel. In other words, in the first embodiment the vessel can all be distributed with bubbles throughout the bulk, except a portion of the transparent window.
The definition of being translucent or opaque should preferably be is based on infrared radiation, for example transmittance of light at a wavelength of 2 μm, because the present invention intends improvement on uniformity of heating and to achieve it, heat is required to radiate through the ceiling portion to the surface of a wafer. A degree of being translucent or opaque is preferably set in the range of 30% to 1% in transmittance of light at a wavelength of 2 μm in order to exert a function as described later.
In order to maintain uniform heating and heat insulation over a long time of operation, according to the present invention, bubbles are included in the bulk of the wall to thereby prevent heat conduction through the thickness. The density of bubbles in the bulk of a heated region in the range of 20,000 bubbles/cm 3 to 100,000 bubbles/cm 3 with diameters of the included bubbles being in the range of 10 μm to 250 μm.
In an internal-heater type apparatus, however, a reactor vessel is constructed in a larger scale, since the heater is contained in the vessel. A water-cooled shroud is installed as a heat shield between the vessel and a heating region and thereby a problem is apt to arise in an aspect of uniformity of heating. Another problem is that pollutants from the heater attach on a wafer and thereby the surface of the wafer is polluted, since the heater is face to face with the wafer.
In a second embodiment of the invention, in which a heater or heaters are installed above the reactor vessel in the region of the ceiling portion, the ceiling portion is composed of substantially transparent quartz glass and almost all the side portion of the vessel covering from the heat-receiving portion to a sealing portion at the lower end of the vessel is composed of translucent or opaque quartz glass with inclusion of bubbles therein. It is preferable that the ceiling portion of the vessel is transparent at a transmittance of 85% or more at a wavelength of light of 2 μm and the side portion of the vessel between the heated portion and the ceiling portion has a transmittance of 30% or less at a wavelength of 2 μm, with a bubble density as described for the first embodiment.
If there exist a clear boundary like that caused by welding between the ceiling portion of the vessel and the side portion, a risk may arise that the boundary portion is locally heated or heat is scattered or reflected there in a poor uniformity and as a result a heated object is heated in a poor uniformity. According to the present invention, no clear boundary of inclusion of bubbles is present between the ceiling portion of the vessel and the side portion. The interface therebetween is composed in such a manner that densities of bubbles change gradually and the gradual change in bubble density preferably occurs substantially in the heated area surrounding the ceiling portion of the vessel.
The position where the wafer is located is preferably in the internal space of the vessel downward of the transparent portion of the ceiling portion.
The second embodiment of the invention secures both a heat insulation effect and uniform heating in a wafer heating region, prevents a portion of the vessel for which heating is unnecessary from being heated, and further effectively stops not only unnecessary reactions, but also both a sealing portion and neighboring parts from being unfavorably affected.
Since transmission of heat is in a lower level in the side portion of the vessel which is translucent or opaque, in other words, since a temperature in the area in the vicinity of the lower-end opening does not rise to an undesirable level, an O-ring is used for sealing by a flange even with no special precaution.
The reactor vessel is placed on a support table above which a wafer is disposed in a predetermined position with a sealing portion lying therebetween and the reactor vessel is preferably separable from the support table in a direction of moving away from each other. A channel for gas feed and an exhaust port are both preferably located on the side of the support table only, but not on the side of the vessel.
Since a reactor vessel and a support table above which a wafer is disposed in a predetermined position are relatively separable from each other in a direction of moving away from each other, loading and unloading of wafers becomes easier. With channels for a fluid attached on the side of the support table only, the reactor vessel and a heater above the vessel combined can be a movable portion, which is shiftable vertically. In other words, simplification of an apparatus comprising the vessel, support table and the like can be realized, because it is not necessary to move the channels for the fluid upward or downward.
Such a quartz glass reactor vessel is manufactured in the following manner in which: first, quartz powders are provisionally shaped in a rotating mold which has an upper opening and the inner shape is similar to the outer shape of the reactor vessel with the dimensions being equal to or slightly larger than those of the outer shape of the vessel. Second, the quartz powder shaped body is molten by directly heating so as to be processed in shapes approximating a hemisphere, a dome, or a cylinder and further to have in the heated region substantially a translucent or opaque portion due to bubbles included in the wall.
With such a technical means, effects of heat insulation and uniform heating of the heated region for a wafer are much improved, because the region itself is composed of quartz glass material, translucent or opaque, with poor heat conductance, in particular, a quartz glass having bubbles included therein with a light transmittance of 30% to 1% at a wavelength of 2 μm. The effect of uniform heating is decreased when light transmittance is 30% or more, and not meaningfully increased when light transmittance is 1% or less.
The transmittance of a light of a wavelength of 2 μm is preferably set so as to be different not only between the internal-heater type and the external-heater type, but also in dependence on a temperature of heat-treatment. For example, in the internal-heater type, the transmittance is preferably set in the range of 1% to 20% under a stress put on the effect of heat insulation and on the other hand, in the external-heater type, the transmittance is preferably set in the range of 5% to 30%, more preferably, in the range of 10% to 30% due to a necessity of a proper extent of transmittance. As to a bubble density, too, the density in the heated region, where bubbles are distributed in a uniform density, is preferably set so as to be different between both types. That is, in the internal-heater type, where the effect of heat insulation is stressed, various bubbles dispersed in the range of 10 μm to 250 μm are preferably included at a density selected from the range of 40,000 bubbles/cm 3 and on the other hand, in the external-heater type, at a density selected from the range of 20,000 bubbles/cm 3 to 80,000 bubbles/cm 3 .
Under conditions of inclusion of bubbles at such a high density and the bulk internally being translucent or opaque, undesirable escape of heat into a region where heating is unnecessary is effectively prevented. This prevention of undesired heating invites increase in uniform heating in the heated region, also realizes thereby a stable level of productivity with a higher quality of product, and in addition allows the use of an O-ring for sealing without a special precaution, since the temperature at the flange portion attached along the outer periphery of the lower-end opening of the vessel does not go up to a high level.
In order to attain a state of being translucent or opaque, a sand-blasting treatment may be used, but this roughens only the surface of a transparent quartz glass body. Consequently, because an effect obtained by the sand-blasting treatment on a surface is restricted to the surface region with respect to being translucent or opaque, when an etching-treatment or heat-treatment is applied to the surface, the surface region becomes transparent. And what's worse, heat is conductible toward the flange side through the bulk of the wall. As a result, the apparatus does not function in a smooth manner.
According to the present invention, since heating is not conducted beyond a necessary region for heating a wafer, undesirable reactions or undesired influences on surrounding facilities do not arise, and heat-conduction outwardly from a heated region is prevented. The heated region and a sealing portion can be close to each other without a water-cooled shroud or water-cooled jacket, so that an apparatus for the use can be constructed in a smaller scale and in a simpler manner.
In a reactor vessel of the present invention, since at least a heated region is composed as a unit not having a welded portion, cracking or breakage due to thermal residual-strain is avoided at the interface.
Being composed substantially as a single body means that no local strain or biased loading in the heated region arises. Under conditions of vacuum and heating at about 1000° C., the region does not lose mechanical strength. With the increase in the mechanical strength, a higher-speed heating-up and higher-speed cooling-down of a wafer in a wafer treatment process is made possible, so that the productivity can be improved.
With a vessel according to the present invention, heating of the wafer is carried out without heating a wider portion than necessary, thereby preventing not only unwelcome reactions, but also undesired influence on the surrounding parts. The heated area and the sealing portion of the side portion can effectively be shielded by the side portion of the vessel therebetween, whereby the heated area can be located close to the sealing portion without a water jacket, so that the vessel is constructed in a small scale and a flat form and the apparatus can be simplified.
The vessel according to the present invention has no clear boundary by inclusion of bubbles between the ceiling portion and side portion thereof and to the contrary bubble densities are gradually changed in magnitude therebetween so as to include no bubble boundary. Thermal mechanical-strength is thus further increased and at the same time gradual descending of temperature along the distance from the ceiling portion of the vessel to the lower-end opening is made possible, so that a heating atmosphere with good balance which makes possible heat-treatment of a wafer with a higher quality is obtainable. Higher speed heating and a higher speed cooling are possible, so that productivity is improved. A transparent window portion is located in the side portion of the vessel with no welded portion so that the vessel is better in regard to airtightness and production.
Since the location of the wafer is in the internal space corresponding to a portion, translucent or opaque, downward of the transparent portion of the ceiling portion, the location is better not only in regard to observation by the naked eye, but also in regard to heat insulation. Exchange of wafers is easier, since the reactor vessel and the support table are separable. In addition, the pipe for introducing a gas and the exhaust port are located on the side of the support table, so that the reactor vessel and the heater portion can be constructed as a single vertically movable part.
Since the reactor vessel is quartz glass and a metal jacket is not used, a built-in window portion and confirmation of the internal state of the vessel are easier to achieve.
A heat transmittance of 85% or more to the wafer can be achieved even in an external-heater type heat-treatment apparatus.
Most of the side portion of the vessel from the ceiling portion to the lower-end opening is composed of bubbled quartz glass with heat transmittance of 30% or less, whereby insulation of the wafer-heating region is improved. Uniform heating throughout the vessel is improved by effective prevention of the escape of the heat to an area where heating is not necessary, so that production with a stable and higher quality becomes possible.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic view illustrating the internal construction of a prior art single-wafer heat-treatment apparatus.
FIG. 2 is a schematic view illustrating the internal construction of another prior art single-wafer heat-treatment apparatus.
FIG. 3 is a schematic view illustrating the internal construction of an external-heater single-wafer heat-treatment apparatus according to the present invention where a reactor vessel as shown in FIG. 4 is used.
FIG. 4 is a sectional view of a reactor vessel used in an apparatus as shown in FIG. 3.
FIG. 5 is a schematic view illustrating the operational principle of an apparatus for manufacturing a reactor vessel as shown in FIG. 4.
FIG. 6 is a schematic view illustrating the internal construction of an internal-heater single-wafer heat-treatment apparatus according to the present invention where a reactor vessel as shown in FIG. 7 is used.
FIG. 7 is a sectional view of a reactor vessel used in an apparatus as shown in FIG. 6.
FIG. 8 is a schematic view illustrating the operational principle of an apparatus for manufacturing a reactor vessel as shown in FIG. 7.
FIG. 9 is a schematic view illustrating the internal construction of a single-wafer heat-treatment apparatus according to the present invention where a reactor vessel as shown in FIG. 11 is used.
FIG. 10 is a schematic view illustrating the internal construction of a single-wafer heat-treatment apparatus according to the present invention where a reactor vessel as shown in FIG. 15 is used.
FIG. 11 is a sectional view of a reactor vessel used in an apparatus as shown in FIG. 9.
FIG. 12 is a schematic view illustrating the operational principle of an apparatus for manufacturing a reactor vessel as shown in FIG. 11.
FIG. 13 is a sectional view of a reactor vessel used in an apparatus as shown in FIG. 9.
FIG. 14 is a schematic view illustrating the operational principle of an apparatus for manufacturing a reactor vessel as shown in FIG. 13.
FIG. 15 is a sectional view of a reactor vessel used in an apparatus as shown in FIG. 10.
FIG. 16 is a schematic view illustrating the operational principle of an apparatus for manufacturing a reactor vessel as shown in FIG. 15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 5 shows an apparatus for manufacturing a reactor vessel in the shape of a cylinder with a dome at the top for use in an external-heater type heat-treatment apparatus as shown in FIG. 3. A mold is attached to a mold holder 11 which is rotatable about a heat source 17.
First, the mold 10 gets rotated together with the holder 11 and then crystalline or amorphous quartz powder is fed into the mold 10 to form a quartz powder layer-like body 18 with a thickness of 20 mm along the inner surface of the mold 10 by means of centrifugal force. In sequence, a heat source 17 is disposed in a middle position inside the mold 10 and melting by heating is then conducted to manufacture a reactor vessel having a predetermined shape.
The thus manufactured vessel 1 (FIG. 4) is processed on the outer surface by grinding and polishing, further the side of the end opening is ground so that the end surface is aligned in a plane perpendicular to the axis of the vessel over the periphery, and if necessary, a flange 2 is joined, so that a reactor vessel 1 can be completed.
A reactor vessel 1 as manufactured in the same way as above was evaluated in regard to a bubble density. In the heated region 1a various bubbles of diameters dispersed in the range of 10 μm to 250 μm were measured at densities in the range of 20,000 bubbles/cm 3 to 40,000 bubbles/cm 3 and the transmittances were less than 30% and in the range of 10% to 20% at the passage of light having a wavelength of 2 μm.
On the other hand, in the non-heated region 1b, various bubbles of the same range of diameters were measured at densities larger than those of the heated region 1a, that is, ranging from 40,000 bubbles/cm 3 to 50,000 bubbles/cm 3 and transmittances were 10% or less at a wavelength of light of 2 μm.
FIG. 8 is an illustration of a method of manufacturing a reactor vessel with an observation-window as shown in FIG. 7. In the method of manufacturing as described above, when a quartz powder layer is formed a piece of transparent quartz glass is located in a desired position in the mold and the quartz powder layer-like body is formed with the piece being inserted within the body built-up and the quartz powder layer-like body is molten by heating from a heat source 17 to manufacture a reactor vessel with an observation-window of a predetermined shape.
A bubble content in each portion of the thus manufactured reactor vessel 20 which is not translucent or opaque was at densities ranging from 40,000 bubbles/cm 3 to 50,000 bubbles/cm 3 for the diameters of counted bubbles in the range of 10 μm to 250 μm.
Transmittances in portions except the observation window 20a at a wavelength of light of 2 μm were measured and the results were transmittances of much less than 30%, that is, in the range of 10% to 5%.
FIG. 3 is a view showing a single-wafer CVD apparatus in which a reactor vessel 1 as shown in FIG. 4 is used, where the quartz glass reactor vessel 1 having a shape like a dome is installed on a support table 3. A flange 2 joins the lower-end opening of the reactor vessel 1 along the outer periphery thereof and an O-ring 4 is embedded in the portion of the flange 2 facing the support table 3 to seal air-tight the interface between the reactor vessel 1 and the support table 3.
The flange 2 is laterally outwardly extended beyond the periphery of the support table 3 and the reactor vessel 1 is lifted by being engaged with a lift 5 at the outwardly extended portion of the flange 2a together with heater 30.
An external heater 30 surrounds the reactor vessel, so that the wafer is uniformly heated. A susceptor 7 of graphite or quartz glass is supported on support table 3, which is equipped with a gas inlet pipe 8 and an exhaust port 9. The susceptor 7 includes an internal heater 30a for heating the wafer 6 from the back thereof and thus the wafer 6 is heated not only on the front by the external heater from outside the reactor vessel 1, but also from the back by the internal heater 30a, so that the time required to reach a temperature at which film formation is carried out is shortened. Since the internal heater 30a is located under the wafer 6 and enveloped by the susceptor 7, there is no danger that particles from the internal heater 30a will pollute the surface of the wafer 6, even though the internal heater is present in the inside of the reactor vessel.
The gas inlet pipe 8 is configured in such a manner that a nozzle 8a attached at the fore-end is aimed in a direction at such a downward angle that the gas may be distributed all over the wafer 6. An inclination angle of the nozzle 8a is in the range of 0 to 45 degrees, preferably in the range of 15 to 30 degrees.
When a CVD film is formed on a wafer 6 by such an apparatus, first, the wafer 6 is heated, in such a state as shown in FIG. 3, to a predetermined temperature by both of the external heater 30 and the internal heater 30a, and then a CVD treatment is conducted while admitting a reaction gas from the nozzle 8a of the gas inlet pipe 8 in the vessel 1, so that a reaction for film formation is performed.
After completion of the film formation reaction, the lifter 5 is shifted upward to lift the reactor vessel 1, so that the wafer 6 is exposed to the air outside the vessel 1 and exchangeable with an untreated wafer 6 with ease.
The aforementioned operations of the treatment are repeatable with simplicity and ease.
FIG. 6 is a view showing a single-wafer CVD apparatus which comprises a quartz glass reactor vessel 20 as shown in FIG. 7, formed as a single body with no welded portion. A susceptor 7 and a heater 30a are disposed in the center region of a support table 3 and rotated by motor 3a and heated by an electrical power source 30b both disposed under the support table 3. An inlet pipe 8 and exhaust port 9 for a reaction gas are provided in the support table 3 and the pressure inside the vessel 20 is kept constant. The reactor vessel 20 is placed on the support table 3 with an O-ring 4 lying therebetween and when occasion demands, a chamber 40 for heat insulation or shading of light may be installed outside of the vessel 20. The reactor vessel 20 is engaged with a lifter 5 by way of flange 2 and moved away from the support table 3 by the lifter 5 in order to remove wafer 6. A transparent portion 20a for observation of the inside from above the vessel 20 is formed in a position on the vessel 20.
In such a manner as described above, in an inner-heater type apparatus, a shorter interval between the wafer 6 and the heater 30a can be realized and a time required for heating-up the wafer 6 from a preheating temperature to a reaction temperature, for example, 1100° C. can also be shortened and thereby productivity is improved.
In both examples, because all piping is attached to the lower surface of the support table 3, in other words, because no part of handling a liquid is attached on the side of the reactor vessel 1, the reactor vessel 1 is shiftable vertically upwardly together with the heater 31 and thereby exchange of wafers 6 and maintenance of all the apparatus are performed more easily. These features make it possible to improve working efficiency and also realize simplification of facilities including the apparatus.
FIG. 12 is a schematic view illustrating the operational principle of an apparatus for manufacturing a reactor vessel of a shape of approximation of a dome according to the second embodiment of the present invention as shown in FIG. 11. The apparatus of manufacturing the reactor vessel comprises a mold 10 which is freely rotatable, a mold holder 11 which detachably holds the mold 10, a motor 12 for rotating the mold 10 together with the holder 11, a coolant channel 13 for cooling the holder 11, a vacuum pipe 14 connected to the bottom 10a of the mold 10 and suction through-holes 10c formed in the side wall 10b of the mold 10, and a vacuum pump 15 and a pressure gauge 16 connected to the vacuum pipe 14. The mold 10 has an internal wall of similar form to the outer form of the reactor vessel. The internal size of the wall is slightly larger than the outer size of the reactor vessel by an amount which is ground off of the vessel 1 after the molding operation. Further, the bottom 10a of the mold 10 corresponding to the ceiling portion 1a of the reactor vessel 1 is composed of gas-permeable carbon and the side wall 10b is composed of gas-tight carbon, where nine through-holes 10c each 0.9 mm in diameter are formed within an area corresponding to the window portion 1c of the vessel 1 in the side portion 10b, in concrete terms, within the square area of a side of 3 cm in the side portion 10b. Upward of the mold 10, a heat source 17 is equipped for melting by heating that is freely shiftable vertically, upward or downward. The vacuum-suction pump 15 is best chosen with an exhaust capacity of 2.5 m 3 /min or more, preferably, of 5 m 3 /min or more. In the example, the exhaust pump 15 having an exhaust capacity of 4 m 3 /min is used.
In the following a method of manufacturing a reactor vessel 1 using the apparatus of FIG. 12 is described. The method comprises the following steps: first, the mold 10 is rotated together with the holder 11; then, crystalline or amorphous quartz powder is fed into the mold 10 to form a shaped quartz powder layer 18 having a thickness of 20 mm along the inner side surface of the mold 10 by centrifugal force. In succession, the heat source 17 is positioned in the middle of the space of the interior of the mold 10; then, the vacuum suction pump 15 is activated to reduce a pressure in the quartz powder shaped layer 18 to as low as a gauge pressure of -600 mm Hg or less, preferably -700 mm Hg or less. Soon after reaching a desired gauge pressure, the shaped quartz powder layer 18 is heated until a thin molten layer is formed on the inner side surface of the layer 18 and further until the molten layer grows to a proper thickness, while the vacuum suction is kept on. When the thin molten layer is formed on the layer 18, a gauge pressure in the layer 18 is lowered to -700 mm Hg or less. Rotation of the mold 10 and melting by heating are continued at this gauge pressure, so that the portion la corresponding to the bottom portion 10a of the mold 10, the window portion 1c becomes transparent, the side portion 1b becomes translucent or opaque, and a reactor vessel 1 having a predetermined form is obtained.
If the reducing of pressure is started after a thin molten layer is formed on the inner side surface of the shaped quartz powder layer 18, minute bubbles unfavorably remain in the molten layer. The reducing of pressure should be started before the thin molten layer is formed, and it is preferably started immediately before starting of the melting by heating or at latest at the same time when starting of the melting by heating. The thus obtained vessel 1 as an intermediate product is ground and mirror-polished both on the outer surface and the inside surface, the end of the opening is ground so as to align all the end surface in a plane, and if necessary the flange 2 is joined with the thus finished end, so that a reactor vessel 1, as shown in FIG. 11, both the ceiling portion la and the window portion 1c of which are transparent and the side portion 1b of which is translucent or opaque is finally manufactured. The bubbles have a diameter in the range of 10 μm and a density of 40,000 bubbles/cm 3 or more, no clear boundary is present between the transparent portion 1a and 1c, and the translucent or opaque portion 1b. The transmittance of the ceiling portion 1a of the vessel 1 was by far more than 85% and more 90% or more in some measured points, the transmittance of the side portion 1b was on the contrary much lower than 40% and in some points 10% or less.
FIG. 14 is a schematic view illustrating the operational principle of an apparatus for manufacturing a reactor vessel 1 as shown in FIG. 13 having area 1d which is halfway in transmittance between the transparent ceiling portion la and the translucent or opaque side portion 1b. Special suction holes 10d in which gas-permeable carbon is filled are formed along the lower end of the side portion 10b adjacent to the bottom portion 10a to realize a gradual change in bubble densities. Bubble content in the half level region were 20,000 bubbles/cm 3 or more when bubbles having diameters dispersed in the range of 10 μm to 250 μm were counted and the transmittance of heat was measured at values of 30% or less, which satisfies a condition of the present invention.
FIG. 9 is a schematic view illustrating the internal construction of a single-wafer CVD apparatus formed by using a reactor vessel 1 shown in FIG. 13 having a shape like a cylinder with a dome at the top placed on a support table 3 composed of quartz glass. An O-ring 4 is inserted between the vessel and the support table 3 to assure airtight sealing between the reactor vessel 1 and the support table 3. The flange 2 extends outwardly of the outer periphery of the support table 3, the reactor vessel 1 is lifted together with a heater lamp by a lifter 5 which engages with the overlapping part 2a. By the lifting, a wafer 6 is relieved to the open air outside the reactor vessel 1, which makes it easy to exchange wafers.
A susceptor 7 of graphite or quartz glass is supported on support table 3, which is equipped with a gas inlet pipe 8 and an exhaust port 9. A heat source 7a is contained in the susceptor 7 for heating the wafer 6 from the back. The wafer 6 is consequently heated by the heat source 7a on the back side thereof as well as by a lamp 30 installed above the transparent ceiling portion la of the vessel 1, so that the wafer 6 is heated up to a temperature of film formation in a shorter time due to both sided heating. Since the heat source 7a is located under the wafer 6 and beside is contained in the susceptor 7, though the heat source 7a is present in the vessel 1, particles produced from the heat source 7a has no risk to attach on the surface of the wafer 6.
The wafer 6 is preferably located in the internal space of the vessel corresponding to the translucent or opaque portion 1b extending downwardly of the ceiling portion 1a of the vessel 1, thereby guaranteeing insulation and uniformity in heating in the wafer heating region. The position of the wafer is also preferably selected so that the height of the wafer 6 is equal to or slightly lower than that of the window portion 1c and thereby a state of film formation on the wafer 6 is observable through the window portion 1c from outside the vessel 1.
The inlet pipe 8 extends vertically to above the wafer 6 and a nozzle 8a attached at the fore end of the pipe 8 is downwardly directed in order that the gas is distributed all over the wafer 6. An angle of inclination of the gas nozzle 8a is preferably set in the range of 0 degree to 45 degrees, more preferably in the range of 15 degrees to 30 degrees. The heating lamp 30 is located above the transparent ceiling portion 1a of the vessel 1.
When a CVD film is formed with the apparatus of FIG. 9, the operation proceeds as follows: first, a wafer 6 is heated from both sides by the heating lamp 30 and the heat source 7a to heat up to a predetermined temperature. Second, a reaction gas is fed from the nozzle 8a of the pipe 8 introducing the gas and the reaction of film formation is carried out. Third, after completion of the reaction of film formation, the reactor vessel is lifted by shifting the lifter 5 vertically upwardly, and finally, as a result, the wafer 6 is exposed to the open air outside the vessel 1 and wafers 6 are exchanged with ease. All the aforementioned steps can be repeated for subsequent film formation on wafers with ease and simplicity.
FIG. 16 is a schematic view illustrating the operational principle of an apparatus for manufacturing a reactor vessel 20 of a shape like a hemisphere having a transparent ceiling portion 20a and a translucent or opaque portion extending to the flange 2 of the lower end opening of the vessel 20 as shown in FIG. 15. This is manufactured in a similar method to that of the aforementioned examples.
FIG. 10 is a schematic view illustrating the internal construction of a single-wafer CVD apparatus formed by using a reactor vessel 1 shown in FIG. 15. A rotary shaft 3b is vertically installed by means of a bearing 3a in the center of a support table 3 and a susceptor 7 is fixedly mounted on the top of the rotary shaft 3b. The susceptor 7 does not include a heat source therein so as not to exert a bad influence on the bearing 3a. The shape of the reactor vessel 1 is however constructed in the shape of a hemisphere, the distance between a heating lamp 30 which is located above the vessel 20 and the wafer 6 is minimized as much as possible, so that the wafer 6 can be heated up to a predetermined temperature in a shorter time.
With the vessel 20 of FIGS. 10 and 15, the distance between the sealing portion 20d of the lower end of the reactor vessel 20 and a ceiling portion 20a thereof is shortened. Since a translucent or opaque portion 20b is formed between the sealing portion 20d and ceiling portion 20a, undesirable conduction of heat and heat deterioration of the sealing portion 20d does not occur.
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A reactor vessel includes a quartz glass body having sidewalls and a ceiling formed as a single unit without welds. Translucent or opaque portions are formed by bubbles in the glass where heat insulation is desired and transparent portions are formed by absence of bubbles where heat transmission and visibility are desired. The body is formed by adding quartz glass powder to a mold which is rotated about a central axis so that centrifugal force causes a layer of powder to form on the inside of the mold. The layer is then heated until it melts.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Continuation application and claims priority under 35 U.S.C. 120 to U.S. patent application Ser. No. 10/866,065, filed Jun. 11, 2004, which claims priority to U.S. Provisional Application No. 60/478,401, filed Jun. 13, 2003, the entire contents of both of which are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention is generally directed to messaging, and more particularly, to managing data collection for alerts over a network.
BACKGROUND OF THE INVENTION
Some services have provided users with alerts of specialized content such as stock quotes. These alert services generally provide content on a single topic to users registered with a specific service. To obtain alerts on multiple topics, a user typically registers with multiple services.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary alert architecture in accordance with the present invention;
FIG. 2 is a functional block diagram illustrating relationships and data flows among functional elements corresponding to the architecture described with regard to FIG. 1 ;
FIG. 3 is a flow diagram illustrating exemplary logic for processing collected content;
FIG. 4 illustrates a poller architecture for managing polled content to produce scheduled alerts;
FIG. 5 is a flow diagram illustrating logic for preparing a time based alert;
FIG. 6 is a flow diagram illustrating exemplary logic for delivering an alert to one or more users; and
FIG. 7 shows a functional block diagram of an exemplary server according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter “with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific exemplary embodiments by which the invention may be practiced. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Among other things, the present invention may be embodied as methods or devices. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. The following detailed description is, therefore, not to be taken in a limiting sense.
Throughout the specification, the term “connected” means a direct connection between the things that are connected, without any intermediary devices or components. The term “coupled,” means a direct connection between the things that are connected, or an indirect connection through one or more either passive or active intermediary devices or components. The meaning of “a,” “an,” and “the” include plural references. The meaning of “in” includes “in” and “on.”
Briefly stated, the invention is direct to a system and method for enabling a user to register an interest and subsequently provide a notification (an alert) to the user when new information becomes available regarding the registered interest. There are several types of content that could be of interest to a user, including, but not limited to, stock feeds, news articles, personal advertisements, shopping list prices, images, search results, and the like. Also, alerts can be provided to the user with any, or all, of a variety of delivery methods, including, but not limited to, instant messaging (IM), email, Short Message Service (SMS), Multimedia Message Service (MMS), voice messages, and the like.
In some cases, a user could select alerts for certain registered interests to be provided by all available methods and other alerts for other registered interests to be provided by only one method. Additionally, some alerts may be provided with a push method to provide relatively immediate notification. In this case, the invention would employ stored contact information to deliver the alert to the user with all selected delivery methods. In contrast, other alerts can be provided with a pull method that replies with the alerts in response to requests from a user regarding other registered interests. The requests can also be scheduled predefined times to provide periodic alerts.
For users that communicate with the invention from behind some Network Address Translation (NAT) device on a network, the pull method employs the connection established by the user's pull request to send the alert to the user. How often the pull alerts are provided is determined by the frequency with which a user makes a pull request of the invention. However, for other users that are not communicating with the invention through a NAT, the push method can be employed at selected time intervals to provide less than urgent alerts.
History of alerts can be provided on a web page for a user. Also, queries for processing alerts for substantially the same registered interests can be combined to enable scaling of the invention to relatively large numbers of users. To further enable scalability, boolean pre-processing and pre-indexing of queries can be applied to new content information for registered interests as the new content information becomes available, such as through an extensible markup language (XML) feed. User profiles can also be provided that include various information, including, but not limited to, Boolean queries for registered interests, delivery methods, time schedules, and the like.
FIG. 1 illustrates an exemplary alert architecture in accordance with the present invention. The alert architecture can be implemented with one or more software modules and/or one or more computing devices such as servers, client devices, and the like. The computing devices generally include a processor, a memory, a communication interface, and input/output interface, a storage device, and/or other conventional computing components. An alert processing system 100 a accesses source content 101 , partner alerts 102 , pull content 122 , and/or other content information for distribution as alerts to client devices. Source content 101 can comprise a variety of content such as personal advertisements, shopping prices, news articles, and the like. Partner alerts 102 further comprise content such as stock quotes, auction bids, and the like that may already be provided as an alert from a topical service. Source content 101 and/or partner alerts 102 can be pushed and/or pulled content. In other words, source content 101 and/or partner alerts 102 can be event based feeds of content and/or scheduled time based feeds of content. One or more feed collection servers 103 receive content and perform input processing as described in further detail with regard to FIGS. 2 and 3 . For content that is not immediate processed, collection servers 103 send the content to storage servers 104 .
One or more matching servers 110 associate content with users who have indicated an interest in receiving alerts about selected content. Generally, matching servers 110 are employed when a content source pushes in content, which is not already associated with a user request. An interest in receiving one or more types of alerts is indicated in user profiles, which are stored in a user database 115 . The user profiles include user identifiers, desired alert types, desired delivery method, and other information. A poller 120 manages requests for content on behalf of users. Generally, poller 120 initiates access to content from content sources. Poller 120 can access some independent pull content 122 from content sources that do not push content to collection servers 103 .
One or more delivery servers 130 are in communication with matching servers 110 and poller 120 . Delivery servers 130 access pull content 122 from poller 120 , pushed content from matching servers 110 , and user information from user database 115 . Delivery servers 130 prioritize and manage distribution of alerts for immediate and pre-scheduled delivery. Pre-scheduled alerts are stored on one or more storage server sets 132 a - 132 n . Each set can correspond to a type of alert, a delivery method, and/or other characteristics. As alerts are prepared and delivered, a user monitor 140 watches the flow of alerts for patterns and/or other insights. Monitor 140 can also track and/or access information about user behaviors, such as navigating to Web sites, making online purchases, and the like. The tracked behaviors also indicate user interests which are stored in user profiles in user database 115 . A logger 142 tracks data associated with individual users, alert types, and other parameters. A debugger 144 is used to trouble shoot problems with processing alerts. When an alert is to be delivered, it is routed to one or more appropriate servers for delivery by the user's preferred method(s). For example, email alerts can be delivered via bulk servers 152 . Alerts to wireless mobile devices can be delivered via wireless servers 154 . Instant message alerts can be delivered via instant message servers 156 . Each alert is generally communicated over a network 160 to a client device identified in the user profile. The user can indicates that the alert be delivered to one or more of a personal computer (PC) 162 , a mobile terminal 164 , a hand-held computer 166 , and/or the like.
A mirror interface 158 can also be used to communicate with one or more mirrored alert processing systems 100 b . All, or portions of the data and processing operations introduced above can be reproduced for parallel processing in the same and/or different locations. Mirror interface 158 can comprise a central communication interface and/or be distributed within each of the servers discussed above, so that each server type can communicate with mirrored server types. At each mirrored alert processing system, the operations of each server type can be customized for locally unique factors.
FIG. 2 is a functional block diagram illustrating relationships and data flows among functional elements corresponding to the architecture described with regard to FIG. 1 . Pushed or pulled source content 170 is receive in one or more forms, including as a hypertext markup language (HTML) document, as an XML document, as a text file, as an email message, as an instant message, and the like. As needed, a collection processing module 172 performs one or more pre-processing operations on the received content to normalize the various forms of content that are received. Normalized content documents are generally indexed by source, time-stamp, content type, and/or other characteristics for easy storage and retrieval in a feed storage 104 a , which also assigns a universal resource locator (URL) based on the storage directory path. The URL is made available to collection processing module 172 for later retrieval. Collection processing is described in further detail with regard to FIG. 3 .
An administration interface 174 is available to access the received data for review and/or administrative functions such as obtaining a status, searching, manually inputting content, and the like. Administrative interface 174 can also be used to set up heartbeat feeds of test content that are tracked to ensure the system is operating properly.
If the content was pushed in from an event based feed, such as a stock price source, the content is relayed to a matching engine 110 a . This relay and/or other communications, such as a time based feed, can be performed via a replicate feed that enables data to be copied from one server to another server. Alternatively, the relay and/or other communications can be performed via a databus feed that enables data to be broadcast until received by all intended recipients. The matching engine determines the users to which an alert should be sent about the received content. The matching engine accesses user profile data 115 a from the user database to associate the content with users who have indicated a desire, or otherwise selected to receive an alert about the content. In particular, a user profile indicates one or more content types for which the user desires an alert, such as traffic incidents, stock quotes, and the like. The user's profile also indicates one or more Boolean queries comprising one or more logical operators, such as AND, OR, NOT, and the like. A sample Boolean query in a user profile is illustrated as:
STOCK AND (COMPANY AND PRICE>$100)
If incoming content type comprises a stock quote, matching engine 110 a applies the Boolean query to determine whether the stock quote content includes information about the selected company and a price greater than $100. If the stock quote does include matching content, matching engine 110 a adds the user to a list of users who desire an alert about the matching content.
Many other users can have a similar query, and/or match the incoming content with different queries. To improve performance for scalability, matching engine 110 a maintains an index of queries and associates each query to those users who desire the same, or very similar, query results. The index of queries reduces duplication of query operations. Future incoming content can be resolved against these pre-indexed queries. For any queries that result in a match, the corresponding user identifier is added to the list. Also taken from the user's profile and included in the list is the user's desired method of delivery such as by email, by instant message, by cellular phone, and the like. Similarly, a desired time for delivery can be specified in the user profile. A message limit can also be provided in the user profile to limit the number of alerts and/or other messages that are sent to the user. The queries can be distributed among computing devices based on the type of content, the current load on the computing devices, and/or other properties. When all queries have been performed for the content, matching engine 110 a prepares to relay the content and list to a delivery interface 130 a.
Prior to relay, matching engine 110 a can also determine priorities based on the user profile data, the type of content, the type(s) of alerts to be sent, and the like. A priority is sometimes referred to as a quality of service (QOS) level. For example, stock price content is typically very time sensitive, so the matching engine can apply a higher priority (e.g., high QOS level) on matching stock price content to users. As another example, the matching engine can use user profile data 115 a to prioritize outgoing alerts to users according to paid service plans and/or other characteristics.
For pulled content using a scheduled time based feed, a poller 120 a requests content for one or more users who desire an alert on an indicated content type. Poller 120 a can pull content from collection processing module 172 or directly from external sources that may not be pre-arranged to feed content to collection processing module 172 . External content is normalized and otherwise pre-processed in the manner described above, unless the requested content is pre-processed by the content sourced prior to be sent to poller 120 a . Further detail regarding the poller processes is described below with regard to FIGS. 4 and 5 .
In any case, when content is to be delivered to an end user, a delivery interface 130 a shown in FIG. 2 generates alerts in one or more methods desired by users. For example, some users may desire alerts delivered as short message service (SMS) messages to a cellular phone number. Delivery interface 130 a generally uses a template corresponding to the delivery method. The template is applied to a content document or a URL to the content document to generate the final alert. Delivery interface 130 a also manages the timing and/or other QOS aspects of alert delivery for each user. For example, some alerts are delivered immediately, while other alerts can be scheduled for later delivery. Other examples include arranging for routing based on geographic location, business partners, content sources, and/or other parameters. Delivery interface 130 a also manages undeliverable alerts, and/or other maintenance issues. Further detail regarding delivery is discussed below with regard to FIG. 6 .
Content Data Collection Processing
Further detail is not described regarding content collection processing. FIG. 3 is a flow diagram illustrating exemplary logic for processing collected content. When content is received, the source is authenticated at an operation 180 . Authentication and/or other security measures can be implemented in one or more ways, including via digital certificates, digital signatures, encryption, virtual private network tunnels, and the like. The source for the content can also be authenticated with domain security mechanisms, including, but not limited to, a domain key application such as provided by Yahoo!, Inc.
At an operation 182 , the received content is converted to a normalize content format, such as an XML format. Table 1 illustrates a sample XML data structure to which received content is normalized for further processing and eventual delivery as an alert.
TABLE 1 Sample XML Data Structure Contact An email address where parse error and data inconsistency can be reported Country The country code of the feed Date The date of the document ExpirationDate The expiration date of the content Url The url ArchiveUrl The url for the alerts feed archive FeedProvider The name of the feed provider (Reuters, AP) The feed providers need to be verified from a config file. Type The type of feed. This field works in con- junction with the edit pages. The edit page saves each alert with a specific type. Each alert type is a string, for example finance/ quotes/real-time/personals. Title The title of the document. Alert_Data The children of this tag can contain any additional data and tags that is needed for the email formatting. Each child tag will be available to the email formatting system as key-value pair.
The following code illustrates a sample normalized XML content document regarding a traffic incident that can be used to generate an alert.
<?xml version=“1.0” encoding=“UTF-8”?>
<AlertsDocument>
<Contact>shi@yahoo-inc.com</Contact>
<Country>US</Country>
<Date>1048495620000</Date>
<ExpirationDate>1048497420000</ExpirationDate>
<Url>http://alerts.yahoo.com/</Url>
<Feed>us_traffic</Feed>
<Type>traffic</Type>
<Title matching=1>
Disabled vehicle
</Title>
<Abstract matching=1>
Disabled Vehicle
</Abstract>
<Body>
Some more descriptive about the incident.
</Body>
<Alert Data>
< DESC>Disabled Vehicle</ DESC>
< LATITUDE>38.554289</ LATITUDE>
< LONGITUDE>−121.406181</ LONGITUDE>
< SEVERITY>2</ SEVERITY>
< STATE>CA</ STATE>
< MARKETCODE>SAC</ MARKETCODE>
< ENDTIME>Mon Mar 24 09:17:00 2003</ ENDTIME>
< ITISCODE>211</ ITISCODE>
<ITISMESSAGE> Some more descriptive about the
incident.</ITISMESSAGE>
...
</AlertData>
</AlertsDocument>
At an operation 184 , the collection processing module validates the content to verify that necessary data was included from the source. Validation can also include updating and/or removing duplicate content that was previously received, and/or ensuring other data integrity aspects. Additionally, validation can include verifying the content as received correctly from the authenticated source. The verification can include validation of encryption/decryption, digital signatures, digital certificates, passwords, symmetric key pairs, asymmetric key pairs, and the like.
Typically, a normalized XML content document can be processed without further modification. However, some modifications can be applied to during a feed transformation operation 185 . In many cases, content feed transformation would comprise minor formatting conversions or simple string substitutions to address validation problems. Nevertheless, more complex logical operations can be performed. For example, an incoming stock quote can be compared to a previous stock quote to determine whether a predefined percentage change has occurred in the stock price. There may be a large number of users who requested an alert when the price of a certain stock changed by a certain percentage since a day's market opening. The collection processing module can pre-calculate a current percentage change prior to associating the stock quote data with users, so that processing resources need not be used or duplicated in determining whether an alert should be sent to the large number of users.
At an operation 186 , the collection processing module also indexes the content to store, search, retrieve, track, and/or organize the content based on a number of metrics. Some of the metrics are inherent in the normalized data structure of the normalized content document, however, the metrics can also be stored in an index document for status information and reports. Example metrics can include the time at which the content was received, an identifier of the sender, a country from which the content was sent, a type of the content, whether the content is associated with a poll request, whether the content is associated with previously received content, and the like. In addition to easing access to a large amount of incoming content, the collection processing module can use the metrics to perform housekeeping and optimization, such as deleting duplicate content, filtering the content to identify minor revisions, and the like, at an operation 188 . For instance, a spelling error may be corrected in a news article, and resent from a content source. A user is unlikely to want two alerts of the same news article with only the spelling correction. If the first news article was already sent, then the second version can be deleted unless difference threshold is exceeded. Alternatively, if the news article was not already sent as an alert, the first version of the news article can be replaced with the corrected version, and queued up so that only one alert is sent to users at a scheduled time. The index document of metrics and/or the content document are generally stored in the feed storage. Each stored index document is identified by an index universal resource locator (URL) for easy access to the index information.
Throughout the above operations, the collection processing module can insert tags and/or other code to assist the matching engine. For example, with regard to the sample XML document described above, the collection processing module can apply an optional ‘matching’ attribute to each immediate CDATA child of the <AlertsDocument> tag. The matching engine can scan the document for ‘matching’ tags and apply the query expression(s) to the text element to determine the user identifiers that match the document.
Poller Subsystem
FIG. 4 illustrates a poller architecture for managing polled content to produce scheduled alerts. There are N numbers of poller servers 190 a through 190 n , and at least two poller manager servers (PMSs), including a primary PMS 192 and a secondary PMS 194 , which generally acts as a backup. Each poller server runs a number of processes that uses non-blocking F/O to handle a number of polls from one or more desired content sources 122 a based on the alert type, such as a personal advertisement, a weather notice, and the like. The desired content could be communicated to poller 120 from the collection processing module and/or accessed independently, such as through an HTTP interface. Each poller server stores identical alerts information per user identifier in database files such as 96 Berkeley DB files. Each file represents a time slot such as 15 minutes—24×4. When an alert request is inserted into the user's profile in user database 115 , a QOS value is calculated based on a provider code, alert type, premium flag, and/or the like. A scheduled alert is communicated to delivery server(s) 130 for distribution at a corresponding period.
FIG. 5 is a flow diagram illustrating logic for preparing a time based alert. At an operation 200 , a poller server wakes up after a predefined period elapses and sends a wakeup signal to the primary PMS. If the primary PMS is down, the wakeup signal is routed to the secondary PMS. The wakeup signal indicates that the poller server is available to poll for content corresponding to one or more predefined alert types. Wakeup signals can be throttled so that the PMS is not overrun with wakeup signals all at once. When the PMS receives a wakeup signal, the PMS adds the currently available poller server to a poller server list in the PMS′ memory at an operation 202 . At an operation 204 , the PMS sends a fetch_alerts_list request to have the first poller server on the PMS's list access one or more content items, such as personal advertisements, traffic reports, and the like. At an operation 206 , the poller server receives the fetch request, accesses the desired content item(s), and sends the content item(s) back to the PMS. To access the content item(s), the poller server performs a query defined by stored user preferences and/or a consolidated query that is desired by numerous users. If no results are found from a query, the poller server can optionally broaden the query and try again. The content item(s) correspond the current predefined period, such as a 15 minute slot. The poller server can prioritize the content item(s) according to QOS levels before returning them to the PMS.
The PMS filters the returned content items from the number of poller servers into tables at an operation 208 . The tables are based on QOS levels of alert types, user service plans, and the like. For example, the content items can be sorted into QOS table 3, QOS table 2, QOS table 1 and QOS table 0 corresponding to priority levels. Each content item would also have a timestamp assigned when the content item is added into one of the tables. The timestamp enables the PMS to track the length of time that the content item has been in a table without being processed into an alert. In general, a content item that stays in a table beyond a threshold length time, indicates that there are not enough poller servers for the load.
In addition to polling for content items at predefined intervals, the polling servers perform operations to prepare corresponding alerts to be delivered. Thus, at an operation 210 , the poller servers send requests to the PMS to ask for work. The PMS generally sends content items from the tables to the poller servers based on the order of QOS levels. The poller servers can perform logical operations such as comparing old query results to the current content item(s). For example, if a current content item is different from an old query result, the poller server can replace the old query result with the current content item. Since scheduled alerts may not be delivered for a long period, the content may be updated a number of times before a corresponding alert is ultimately delivered. Once a poller server finishes its work, the poller server sends an acknowledgment to the PMS, indicating that the content item has been processed and an alert has been created. The poller server also sends a request to the delivery server to deliver an alert with the content item, and the poller server asks for more work. Upon receiving the acknowledgement, the PMS removes the content item from its corresponding table, at an operation 212 , indicating that the corresponding alert task is complete.
At a decision operation 214 , the PMS determines whether all content items from each table were removed, indicating that all tasks for each QOS level were completed. If each table is empty, processing returns directly to operation 200 to await another wakeup signal. If each table is not empty, the PMS was not able to complete all of its tasks, and the PMS may log an error. Any remaining unprocessed content items are merged, at an operation 216 , with any new content items that are obtained during the next period.
Delivery Subsystem
FIG. 6 is a flow diagram illustrating exemplary logic for delivering an alert to one or more users. As briefly discussed above, the delivery servers and storage servers generally comprise a delivery subsystem for interfacing with transmission servers to deliver alerts in a variety of methods. All components of the delivery subsystem can comprise any combination of hardware and/or software configurations. This flexibility enables deployment of alerts in varying circumstances, such as on international sites with limited hardware resources.
At an initialization operation 220 , such as when a delivery server is newly installed or returned to service after being offline for some time, and/or at a certain predefined periods, the delivery servers receive updated templates from another live delivery server and/or from another source such as the administrative interface. All delivery servers should have the same set of templates automatically propagated throughout the delivery servers set.
At an operation 221 , the delivery server(s) receive one or more requests from the matching engine and/or the poller to deliver one or more messages to one or more users. The requests generally include a set of keys and values associated with each key. The keys correspond to placeholders in delivery templates that correspond to delivery method, such as email, instant messenger, SMS, Web server, file transfer protocol (FTP) delivery, and the like. For example, a key-value pair of <fullname, John Smith> in a request will be used to replace a ‘fullname’ placeholder in a selected delivery template. The delivery templates can be written in well known template languages such as personal home page hypertext processing (PHP), JAVA™ server pages (JSP), HTML Force 2000 (HF2K), and/or a proprietary template language. The content type, such as stock quotes, news, classifieds, and the like, can be used by the delivery server to determine which set of delivery templates to use. For each content type, a set of delivery templates can be created for the different available delivery mechanisms such as HTML page server, text file transfer, Instant Messenger, SMS, and the like. However, the delivery servers generally do not have any knowledge of a specific alert document to be processed. Instead, the delivery servers simply see a document comprising the content and the user ID list. This combination of content document and user ID list is sometimes referred to as a ProcessMatchList. As described above, the user ID list comprises those user IDs that matched a specific content feed. The content document comprises a set of key-value pairs that represent the actual content of the alert to be sent. There can be a set of key-value pairs for each delivery method, including, but not limited to, one pair for email delivery, one pair for wireless delivery, one pair for IM, and one pair for web history, which is explained below. In addition to the key-value pairs identified in Table 1 above, the ProcessMatchList also generally includes the following information from a user's profile for delivery purposes:
User ID code from user database; Country code for delivery; Partner ID associated with the alert content and/or delivery method; A User category; QOS level; Scheduled versus immediate delivery flag; Premium service package information; Pass through billing information that may be need such as for mobile delivery.
The information above can also be used for logging/statistical purposes, to determine the actual template used to format the alert content, for any billing activity on the last leg of the delivery path through mobile service providers, email providers, and the like.
Upon receipt of a ProcessMatchList, the delivery servers determine, at an operation 222 , the QOS level associated with each user and/or delivery method identified in the ProcessMatchList. The delivery server will process requests in accordance with QOS levels in both inbound and outbound queues. A message from the match servers generally ends up in the appropriate inbound queue according to the priority level of the users that the queue contains. An alert generated from the delivery server generally ends up in the appropriate outbound queue according to whether the alert is to be send via email, wireless SMS, IM, and/or the like. In addition, or alternatively, the delivery servers can ensure that premium users will have special delivery options if, for example, the user database is down. The storage servers store a last known email address, wireless device number, and/or the like, that is known about each user. The delivery server retrieves that information from the storage server in case the delivery server cannot get the information from the user database. The delivery server can also enforce a message limit per alert, per wireless device, per user, and/or the like. The delivery server will interface with the storage server to store/retrieve message limit information.
At an operation 224 , the delivery server determines whether any kind of block or rerouting has been placed on delivery of alerts to certain users and/or through certain delivery methods. For example, a user may have indicated quiet time during which the user does not wish to receive any alerts, such as during evening hours. Similarly, a user may be on vacation, and has requested that no alerts be delivered until the user returns. The delivery server can also determine whether alerts should be forwarded through any number of delivery methods beyond the user's primarily preferred method.
At a decision operation 226 , the delivery server determines which alerts are to be sent immediately and which are to be sent at a scheduled time. Those alerts that are scheduled for later delivery will be stored on the delivery storage servers. There are at least two ways to implement the delivery storage servers, referred to herein as option A and option B.
Option A:
For scheduled alerts, a resource manager server (RMS) determines, at an operation 228 , which users' alerts get stored on which storage servers. Any delivery server that needs to store an alert for a user, will first lookup the user's corresponding alert settings in the user database to locate a StorageId where alerts are to be stored. If no such StorageId exists, then the delivery server contacts the RMS to get a StorageId. The RMS will decide which storage server on which the user's alerts will be stored, depending on the current load/usage of each of the registered storage servers. A serverId will be returned to the delivery server which will then store the StorageId in the alerts settings in the user database. For failover purposes, or if the RMS is down or non-responding, an RMS API will ensure that the last issued StorageId is passed as a result on any subsequent queries to the RMS, until it comes back up.
Once the appropriate storage server is identified, the delivery server stores the user's alert(s), and (optionally) their delivery options, to that storage server, at an operation 230 . In addition to simply waiting for later delivery, stored alerts may be compared to newer alerts to ensure the most recent content. For example, a user should receive only one single alert for a news story that was updated multiple times in a day, although multiple matches may be generated from the updates over a period of time before the scheduled delivery time.
As with the delivery servers, the storage servers generally will have no knowledge of any alert-specific information. The storage servers will make every attempt to store information in a share memory (e.g., shm) for fast retrieval, and use disk storage as little as possible. For efficiency, any information common to a large number of users, such as content feed information, can be stored once and indexed to the users. In one embodiment, there can be at least four storage areas in each server, which can be implemented via a combination of shared memory and disk write back:
Feed storage: each collection of key-value pairs would be stored once for the whole set of users matched to the type of content feed. User Storage: an entry for each user interested in receiving a scheduled alert. This area is needed for fast access to a user's record in case they decide to delete/edit the alert. Time storage: each user interested in receiving a scheduled alert will have a record stored under the appropriate time slot and the appropriate service queue. Web Storage: Every delivered alert will have a permanent record with a pointer to the feed that created it, for usage on a web front end.
For failover and faster retrieval of scheduled alerts, any of the servers can be mirrored. Each server can act on a subset of alerts, such as via a modulo algorithm. For each action, such as delivering a scheduled alert, a server will replicate the action to one or more peer mirrors. A heartbeat mechanism is generally established between processes that perform scheduled deliveries, so that if a server goes down or the process fails for some reason, the remaining processes on the mirror servers will continue doing the work. This takes advantage of the mirror servers, not only for failover, but also to multiply (e.g., double, triple, etc.) the available processing power.
Option B:
In an alternate embodiment of the delivery storage server, a relational database stores feed content relative to alert matching results. Conceptually, three types of tables are used to associate feed content, user alert matches, and delivery schedule times. Accordingly, the three types of tables are called Feed table, AlertMatches table, and TimeSlot table. The Feed table contains each content feed that is received by the storage server. Each content feed is uniquely identified by a FeedId. A sample Feed table data structure is shown in Table 2.
TABLE 2
Sample Feed Table Data Structure
Data Field
Data Type
FeedId
Text
FeedContent
Text
ExpirationDate
Timestamp
CreationTime
Timestamp
The AlertMatches table stores the user matches for every alert. A user's alert is referenced by a unique AlertId. For each AlertId there may be 0 or more content feeds. Several matches for one AlertId will be represented by multiple rows in the AlertMatches table, each row having a different FeedId. Each tupel <AlertId, FeedId> is unique in the AlertMatches table and ties a user's alert to the corresponding content feed. A sample AlertMatches table data structure is shown in Table 3.
TABLE 3
Sample AlertMatches Table Data Structure
Data Field
Data Type
AlertId
Text
FeedId
Text
CreationTime
Timestamp
Timeslot tables store the alert ids of all users associated with a delivery time slot. Each 15 minute delivery time slot during the day corresponds to one Timeslot table. For example, a table TimeSlot — 9 — 45 includes all alert ids that have delivery preferences set to 9:45 am. At the start of each delivery slot, a number of processes begin processing the alert ids in a TimeSlot table. To coordinate these processes, a ‘ClaimedBy’ field in the TimeSlot table allows each process to check whether another process is already working on a specific alert id. If the ClaimedBy field is empty, this alert id is available to be processed by the next available process. A sample TimeSlot table data structure is shown in Table 4.
TABLE 4
Sample TimeSlot Table Data Structure
Data Field
Data Type
AlertId
Text
QosLevel
Int
Dst
Int
ClaimedBy
Int
While alerts are in storage, the delivery storage server will also get updates from the user database, at an operation 232 . One reason for this is to remove user entries whenever a user deletes an alert or whenever a user decides to change the delivery time of a scheduled alert. At predefined delivery periods, such as every hour, the storage servers access those stored alerts that are to be delivered at that period, and mark those stored alerts for immediate delivery. The storage servers then send those marked alerts to the delivery servers at an operation 234 . At an operation 236 , the delivery servers apply a template to format the outgoing alerts according to the pre-selected delivery method if the template was not previously applied. The delivery servers then communicate the immediate delivery alerts to the transmission servers for delivery via email, instant message, SMS, and/or whichever delivery method(s) are associated with each alert.
Once an alert has been sent out by a delivery server, an “addToHistory” request is sent to the storage servers, at an operation 238 , to update the user's history with the fact that an alert has been sent out. The “addToHistory” request also comprises a set of key-value pairs, so that different alert types can store different sets of information. Once again, the delivery server generally has no knowledge of the specific alert for which it is sending the “addToHistory” request. The set of key-value pairs that need to be stored are defined by the matching side. Every request to the delivery server should also be accompanied by any set of key names that need to be stored for the specific alert.
The history information can also be broadcast from the storage servers to other services. For example, history results can be served to front end Web pages and/or other Web Portal pages, either directly from a mirrored set of storage servers, or from a separate set of storage servers that serve history results. A shared memory can hold as many users' history results as possible (updated live as “addToHistory” requests come in from the delivery servers), and at the same time history results can be written to disk for permanent storage. If a user's top N history results are not in shared memory, the history results can be accessed from the user's permanent storage file. As indicate above, the results will be returned in key-value pairs, and it will be up to the receiving side to format the results in manner that is appropriate to the receiving side. For example, an actual news alert might have been sent to a user with a URL and an abstract of the last 3 news alerts that the user has received, whereas a history page might only need to present the URL. Independent formatting enables new alert types to be added without altering what is stored in the history files, thereby accommodating a new alert type with new requirements for history reporting. In general, the key-value approach will fit future needs.
A number of measures are employed to ensure that information is not lost in an event of a catastrophic failure, a corruption problem, or even a need to upgrade the servers. As indicated above, each storage server is mirrored at least by one other server, so that a server can be taken down while its mirror(s) handle the traffic. Backups of the shared memory and replication files can be employed. For example, at least twice daily backups of the shared memory can be employed, as well as at least 24 hours worth of incoming replication volume files, enable recreation of the shared memory as fast as possible to bring a server back online.
Other recovery capabilities ensure complete processing of delivery requests. For instance, a deliver server marks an alert as “done” only when all user IDs associated with the corresponding content document have been processed. The monitor and/or other utilities can monitor the state of unsent alerts and have alert processing repeated if necessary. This recovery capability can also be applied to the transmission servers.
In addition to ensuring recovery, mirror sets can be used for scalability. To handle increased traffic from the match servers, any number of additional delivery servers can be added at any time. Conversely, any delivery server can be taken offline at any time for any maintenance reason. The remaining live servers will handle the incoming traffic from the match servers.
To handle increased user registration, any number of storage servers can be added horizontally, wherein more total mirror sets are added. To handle increased scheduled alert activity, storage servers can also be added vertically, wherein more mirror servers are added per set.
Illustrative Server Environment
FIG. 7 shows a functional block diagram of an exemplary server 300 , according to one embodiment of the invention. Server 300 can comprise any one or more of the servers discussed above, such as the matching servers, the feed storage servers, the poller, the delivery servers, the storage servers, the transmission servers, and the like. Client devices can be similarly configured. Server 300 may include many more components than those shown. The components shown, however, are sufficient to disclose an illustrative embodiment for practicing the invention.
Server 300 includes a processing unit 312 , a video display adapter 314 , and a mass memory, all in communication with each other via a bus 322 . The mass memory generally includes RAM 316 , ROM 332 , and one or more permanent mass storage devices, such as an optical drive 326 , a hard disk drive 328 , a tape drive, and/or a floppy disk drive. The mass memory stores an operating system 320 for controlling the operation of server 300 . Any general-purpose operating system may be employed. A basic input/output system (“BIOS”) 318 is also provided for controlling low-level operation of server 300 . As illustrated in FIG. 6 , server 300 can communicate with the Internet, or some other communications network, such as network 160 of FIG. 1 , via a network interface unit 310 , which is constructed for use with various communication protocols including transmission control protocol/Internet protocol (TCP/IP). Network interface unit 310 is sometimes known as a transceiver, transceiving device, network interface card (NIC), and the like. Server 300 also includes input/output interface 324 for communicating with external devices, such as a mouse, keyboard, scanner, or other input devices not shown in FIG. 1 .
The mass memory as described above illustrates another type of computer-readable media, namely computer storage media. Computer storage media may include volatile, nonvolatile, removable, and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. Examples of computer storage media include RAM, ROM, EEPROM, flash memory, or other memory technology, CD-ROM, digital versatile disks (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage, or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computing device.
The mass memory also stores program code and data. One or more applications 350 are loaded into mass memory and run on operating system 320 . Examples of application programs include database programs, schedulers, transcoders, email programs, calendars, web services, word processing programs, spreadsheet programs, and so forth. Mass storage may further include applications such as collection processing module 172 , admin interface 174 , matching engine 110 a , poller 120 a , delivery interface 130 a , and the like.
The above specification, examples, and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
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Managing data collection for one or more scheduled alert messages. A primary or backup poller manager coordinates any number of poller services to access content and generate the alert messages. At a predefined period the poller manager is informed that an existing or new poller service is available for work. The poller manager provides a query to the poller service to access content in which one or more users have expressed an interest. Querying for a large number of users can be subdivided among the poller services. The poller service can also automatically expand the query if it yields insufficient content. The poller service generates the alert messages for the interested users and informs the poller manager when done. A change in content can be used to generate or update alert messages before their scheduled delivery. The poller manager prioritizes processing with a quality of service level.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of application entitled "BROADBAND SWITCH USING DEACTIVATED CROSSPOINTS FOR ESTABLISHING SWITCHING PATHS" filed Dec. 11, 1991 as Ser. No. 07/808,032 and issuing as U.S. Pat. No. 5,285,202 on Feb. 8, 1994, which is a continuation of Ser. No. 07/347,370, now abandoned, filed May 4, 1989 by the same inventors and assigned to the same assignee as the present application. The application is hereby incorporated by reference. This application is further related to U.S. Pat. No. 5,049,877, herein incorporated by reference.
FIELD OF THE INVENTION
This invention relates to telecommunications facilities and, more particularly, to a broadband switch.
BACKGROUND OF THE INVENTION
The source of speed limitations in conventional space switch arrays is illustrated by considering a K×J matrix including K inputs each of which can be connected to the J outputs by closing the switch at the intersection of an input/output line. The switches have associated stray capacitances that cause speed degradation. Therefore, the speed decreases as the size of the array is increased. For example, by closing a switch S11 at the intersection of row 1 and column 1, input 1 is connected to output 1. Even though inputs 2 to K are not connected, they contribute to the stray capacitance of column 1. Similarly, even though columns 2 to J are not connected, they contribute to the stray capacitance of row 1. It can be seen that input line 1 must charge (J-1)+(K-1) capacitors. The finite resistance in series with line 1 and column 1 forms an RC time constant that limits the speed of operation. As the array size is increased, this stray capacitance also increases and the speed continues to decrease.
The stray capacitance of the horizontal rows can be overcome by providing sufficient drive to the input lines. The most detrimental effect is caused by connections to the vertical lines. This is due to the fact that each of the switches at the crosspoints is implemented with an active circuit that must drive the vertical line and its associated capacitive loading. It does not help to make the active switch element larger so it can drive more capacitance because the stray capacitance increases in almost direct proportion to the size of the active switch.
SUMMARY OF THE INVENTION
The present invention relates to a switch comprising a plurality of switching means configured as a multistage tree-multiplexer wherein a first stage of said tree-multiplexer receives input signals, and a last stage includes a single switching means coupled to an output port; each of said switching means having a plurality of signal inputs, an output, and a control input means; each switching means in said first stage further comprises a pass-transistor selection means having a control input coupled to the respective control input means of said switching means, a plurality of signal inputs each coupled to receive a respective input signal, and an output; each of said selection means being responsive to said respective control input for selectively switching a signal from a selected one of said signal inputs to the output of said selection means; wherein the output of each switching means before the last stage drives a respective input of a switching means in the immediately following stage, and the output of the single switching means in said last stage is coupled to said output port; each of said switching means after the first stage being operable in a blocking state to force the output of said switching means to a predetermined steady-state logic value in response to a first control signal at the respective control input means; and each of said switching means after the first stage being operable in an unblocking state to selectably switch a signal from a selected input of said switching means to the output of said switching means in response to a second control signal at the respective control input means, and in response to output signals from switching means in the preceding stage which are in said blocking state.
In accordance with one aspect of the present invetion, each of said switching means after the first stage includes a NAND gate; said first control signal is a logical LOW state signal; said second control signal is a logical HIGH state signal; and said predetermined steady-state logic value is a HIGH state signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit representation of a conventional space switch matrix;
FIG. 2 is a circuit diagram of a switch module in accordance with a preferred embodiment of the present invention;
FIG. 3 is a circuit schematic of a selector circuit employed in the FIG. 2 switch in accordance with a preferred embodiment of the present invention;
FIG. 4 is a circuit schematic of a NAND gate configuration employed by the present invention;
FIG. 5 is a circuit schematic of an inverter configuration employed by the present invention;
FIG. 6 is a circuit diagram of a distributed switching control assembly in accordance with a preferred embodiment of the present invention; and
FIG. 7 is a circuit layout of a broadband switch architecture in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a circuit representation of the conventional space switch matrix discussed supra in the Background of the Invention section. As indicated, each switch crosspoint at the intersection of a vertical and horizontal line contributes capacitance that limits the speed and size of the array.
FIG. 2 is a circuit diagram of a 64×1 switch module in accordance with a preferred embodiment of the present invention. The 64×1 switch module is for illustrative purposes only and should not be construed as a limitation of the present invention, as it should be apparent to those skilled in the art that switch modules of varying dimensions may be designed according to the present invention following the principles discussed herein.
The switch module includes six (6) cascaded stages each performing controllable switching of signals from an input end to an output end which is then connected to an input end of a next stage. The circuit elements of the array each enclose a numeral identifying the relevant stage. The array comprises a stage no. 1 including pass-transistor selector elements 21, stages no. 2-6 each including NAND gate elements 22, and inverter elements coupled to certain NAND gate outputs.
The array is designed so that the output of each circuit element drives only one input of a circuit element in the next stage. For example, the output of each selector 21 in stage no. 1 drives a single input of NAND gate 22 in stage no. 2. Likewise, the output of NAND gate 22 drives a single input of a respective NAND gate 23 in stage no. 3. The selector element inputs are each coupled to receive a respective input signal from a corresponding input port. The array is operable in response to control signals C0 to C5 and their complementary values for switching a selected input signal through the array to the output port.
The true and complementary values of control signals C0-C1 serve as the control inputs for stage no. 1. The circuit elements (e.g., NAND gates) in the remaining stages no. 2-5 are each controlled by the true and complementary values of a single one of the control signals C2-C5. For example, the true and complementary values of control signal C2 control the switching in stage no. 2. The control is established within stages no. 2-5 such that for those gates in a stage whose outputs are coupled to respective inputs of the same NAND gate in the next stage, one of the NAND gates receives a true value of the control signal while the other NAND gate receives the complementary value. For example, since the outputs of NAND gates 22 and 26 are coupled to gate 23 in the next stage no. 3, gate 22 receives the true value of C2 while gate 26 receives the complementary value.
In stage no. 1, the switching occurs in the following manner. Each selector element 21 includes as control inputs the true and complementary value of control signal C0, and either the true or complementary value of control signal C1. As indicated, the output of each selector element is paired with the output of another selector element for supplying the input signals to the dual-input NAND gates in the next stage. For example, the outputs from selector elements 21 and 28 are coupled to respective inputs of NAND gate 22 in stage no. 2. However, these paired selector elements must be operable such that only one of the selector elements furnishes a data signal to the next stage no. 2.
The selector elements exhibit two levels of switching. For illustrative purposes only, assume that input signal 1 at input 20 of selector 21 is to be switched to the output of stage no. 6. First, the selector elements in stage no. 1 are responsive to the control signal C0 and its complementary value for initally selecting either the upper input 20 or lower input 19 for further switching. In particular, when C0=+5 V, all upper inputs are selected. The next level of switching is performed by control signal C1 such that when C1=+5 V and its complementary value equals OV, all stage no. 1 selector elements allow the selected input to propagate to a corresponding NAND gate in stage no. 2, while the stage no. 1 selector elements connected to the complementary value of C1 are forced to a +5 V output value. The C1 control input connections in stage no. 1 are designed such that for paired selector elements, one of the selector elements receives the true value of C1 while the other receives the complementary value of C1. For example, selector 21 receives the true value of C1 while selector 28 receives the complementary value of C1.
For the stages no. 2-5, a +5 V signal level for the true values of control signals C2-C5 establishes a switching path along the bolded route through NAND gates 22, 23, 24, 25, and 26.
As illustrated in FIG. 2, each input port is connected to the output port via a cascade of selectors, NAND gates, and inverters. The high operational speed demonstrated by the switch module is based upon the particular interconnectivity between stages wherein each output drives only one corresponding input of a circuit element in a next stage.
The two inverters between stages 5 and 6 are used to prevent the connection between these two stages from becoming excessively long. The connection between stages is preferably limited to less than 200 μm, which is 0.015 pF in 3-μm technology. A direct connection between stages 5 and 6 would result in an 800 μm (0.06 pF) interconnection and reduce the speed.
The following discussion relating to FIGS. 3-5 concerns a description of the various circuits employed in the switch module of FIG. 2. In the legend of FIGS. 3-5 is a chart of the width versus length (W/L) ratios of the transistors used in the relevant circuit element.
FIG. 3 represents a circuit schematic of each selector element in stage no. 1. The selector element employs a pass-transistor 33 for input selection, followed by a NAND gate 30 with an override control input. The selector element configuration includes a first switch 31 of a complementary pair of a P-type and an N-type MOS field effect transistor TP2 and TN5, respectively, connected in parallel between input connection 2 and a common juncture 27. A second switch 32 of a complementary pair of a P-type and an N-type MOS field effect transistor TP1 and TN6, respectively, are connected in parallel between input connection 1 and the common juncture 27. The gate of the P-type transistor TP2 of the first switch 31 and the gate of the N-type transistor TN6 of the second switch 32 are connected together and to a first control input connection C0. The gate of the N-type transistor TN5 of the first switch 31 and the gate of the P-type transistor TP1 of the second switch 32 are connected in common to a second control input connection corresponding to the complementary value of C0.
The first level of switching action in the selector element is effected by placing a relatively high control voltage at the first control input connection C0 and a relatively low control voltage at the second control input connection receiving the complementary value of C0. These voltages applied to the respective gates cause the transistors TP2 and TN5 of the first switch 31 to be biased to the nonconducting or OFF condition, thus presenting an open switch between the input connection 2 and the juncture 27. These control voltages bias the transistors TP1 and TN6 of the second switch 32 to the conducting or ON condition, thus providing a closed switch between the input connection 1 and the juncture 27.
Alternatively, when the control voltage at the first control input connection C0 is low and the control voltage at the second control input connection receiving the complementary value of C0 is high, transistors TP1 and TN6 of the second switch 32 are biased to provide an open condition between input connection 1 and juncture 27, while transistors TP2 and TN5 of the first switch 31 are biased to provide a closed condition between input connection 2 and juncture 27. In summary, when C0 is +5 V (complementary value of C0 is 0 V), the switch having transistors TN6 and TP1 is turned ON, and the switch having transistors TN5 and TP2 is turned OFF, thus connecting input 1 to node 27. The opposite transistor conditions result when the true value of C0 is OV and the complementary value is +5 V.
The second level of switching action in the selector element of FIG. 3 is performed by NAND circuit 30, wherein transistors TP3, TP4, TN7, and TN8 form a 2-input NAND gate. When the C1 input at node 8 is +5 V (whether as the true or complementary value), input 1 or input 2 appears at the output (depending upon which input was selected by pass-transistor element 33). When the C1 input is 0 V, the output is forced to +5 V regardless of the input selected by element 33. The sizes of transistors TP4 and TN8 were designed to optimize the speed from node 3 to the output.
As shown in FIG. 2, the configuration for stages no. 2-5 is basically a 3-input NAND gate with one of the inputs used for control. Although the switch implementation disclosed herein includes NAND gates, this should not be construed as a limitation of the present invention since other switch configurations may be developed which employ circuit elements other than NAND gates. A circuit schematic of a representative NAND gate is shown in FIG. 4. Transistors TP6 and TN5 are preferably designed to optimize speed for inputs 1 and 2. When the control signal is at a HIGH value (+5 V), the circuit functions as a NAND gate for inputs 1 and 2. Alternatively, when the control signal is at a LOW value (0 V), the output is forced to +5 V regardless of the input states.
The NAND stages are used because they provide the optimum speed in CMOS technology. The first stage is an exception, where pass-transistors are used for input selection. Although this pass-transistor configuration for stage no. 1 is slower than would be for a NAND gate implementation, it was used to simplify interconnection within the 64×1 module. By doing this, two levels of selection are performed by one stage. Since stage-1 contributes the largest number of gates, this approach resulted in minimum area.
FIG. 5 is a circuit schematic of an output buffer or driver circuit 35 corresponding to an inverter element which includes a P-type MOS field effect transistor TP1 connected between a voltage source of +5 volts and the output connection 36 and an N-type MOS field effect transistor TN2 connected between the output connection 36 and ground. The gates of the two transistors TP1 and TN2 are connected in common to the juncture 37.
In the block diagram of FIG. 2, stages no. 1-5 preferably utilize minimum size transistors for reducing chip area and power dissipation. The minimum size transistor stages are capable of driving similar stages having input capacitances on the order of 0.05 pF. In order to drive off-chip, where the capacitance is on the order of 5 pF, an output buffer is required. Such a buffer is formed by cascading inverters that utilize progressively larger transistors (formed by connecting smaller transistors in parallel). This was done to prevent the speed deterioration due to the distributed RC in the gates of large transistors.
In order to maximize the data rate, the transistor sizes are preferably increased gradually. The increase in transistor size is started by doubling the sizes of the transistors in the second inverter at the output of stage-5. The transistor increase factor is indicated by 2X on the circuit diagram of FIG. 2. Stage-6 is made 4X. The first stage of the six stage buffer (shown to the right of FIG. 2) is 6X and is physically located next to stage-6 of the switch. The second stage of the buffer is also 6X. The same transistor size was maintained to compensate for the relatively long physical separation between stage-1 and stage-2 of the buffer. The remaining buffer stages keep increasing by a factor of two until the last stage reaches 64X. Computer simulation indicated that this buffer design is capable of 200 Mb operation with a 10 pF load.
The 64×1 module has many levels of symmetry and modularity, as shown in FIG. 2. The smallest module is two stage-1s driving a stage-2. The next higher level of modularity is two stage-2s driving a stage-3. The outputs of stage-3s are combined in a stage-4 by making the right side a mirror image of the left side, which forms a 16×1 and feeds the left input of stage-5 (NAND gate 25). A mirror image of the 16×1 feeds the right input of stage-5, whose output is the upper input of stage-6 via two inverters. The lower input of stage-6 is supplied from a 32×1, which is a mirror image of the upper 32×1. This technique of modularity and symmetry immensely simplified the design, simulation, and layout. It also equalizes the delays from each input to the output to a fraction of a nanosecond.
FIG. 6 illustrates a preferred implementation of the control unit for the 64×1 switch module in FIG. 2 supplying control signals C0×C5. The control unit includes a 6-bit shift register with serial-to-parallel conversion. The six parallel bits are loaded into six latches when the strobe pulse ST is applied. The latches provide the 12 true and complementary control lines and the capacitive drive. In the expanded space array configuration discussed infra in connection with FIG. 7 wherein sixteen of the FIG. 2 switch modules are connected in parallel to provide a 64×16 matrix, the serial shift register output from module N is directly applied to serial input of module N+1.
FIG. 7 shows a circuit layout of a 64×16 space switch matrix in accordance with a preferred embodiment of the present invention. The matrix chip includes sixteen of the 64×1 switch modules from FIG. 2 connected in parallel. Accordingly, the chip is organized into 64×1 modules, each of which contains an output driver and its own control storage. The 64 inputs are supplied from both sides, (i.e., 32 inputs from the right and 32 inputs from the left). These 64 common input lines run horizontally across the chip using metal layer #2. Also, the +5 supply voltage and ground are supplied from the right and left sides of the chip. The output from each 64×1 connects to a driver located at the bottom of the 64×1 module.
Various considerations dictated that the 64×16 space matrix should be formed by tall and slim 64×1 modules. One of the most important considerations was allowing room for connecting 64 inputs. The other consideration was simplifying and reducing design effort. This symmetry also simplified design, simulation, and layout at the global level since a 64×1 layout can easily be made into a 64×1 or any other number of outputs allowed by chip area and package pins. In order to maintain this design philosophy, the control shift register, control store and output driver was designed into each 64×1 module.
Each 64×1 module is controlled by six bits, which produce 2 6 =64 combinations. Both true and complementary controls are required, resulting in 12 control lines. The complementary control lines are generated on chip, therefore only six control bits need to be supplied externally to control each 64×1 module. For 16 modules, 16×6=96 control bits are required. In order to conserve package pins, the 96 control bits are supplied serially to the shift register, which converts the control to a parallel format and stores the code in 96 latches. The latches provide buffering and create the complementary control lines. The 12 control lines to each 64×1 module are connected vertically using metal 1. The shift register uses two externally supplied clock phases for clocking in the 96 control bits. A control bit can be read in every 100 ns, thus 100 ns×96=9.6 μs is required to read in a control word. As a new control word is read in, the latches hold the old control information so that the switching is not disrupted.
The control shift register and control store for the 64×16 is distributed among the 16 modules so that each module has its own independent control. When modules are assembled, the control shift and control store are automatically interconnected.
The shift register and the control latches are implemented with static logic so that the old control and the new control information can be stored indefinitely. At any time after the new control information is in the shift register, the shift register contents can be transferred in parallel to the 96 latches with a strobe pulse (ST). This operation requires 30 ns. Thus, the entire 64×16 switch is reconfigured 30 ns after the ST pulse is applied, and the newly reconfigured outputs become valid at the 16 output pins. The serial shift register output is made available off chip. This was done to verify that the correct control information is in the shift register. This verification can be done in several ways.
1. After the control information is written into the shift register, it can be recirculated and verified for correctness.
2. The control information can be written twice and the shift register output compared to the second write operation.
3. The shift register can be read out after it is transferred to the latches. This erases the shift register contents, but it has the advantage of not requiring a second write operation when reconfiguration speed is critical.
It is important to note two reconfiguration delays:
1. The delay from supplying the new control word to the appearance of new outputs is about 10 μs.
2. The delay from supplying the strobe (ST) to the appearance of new outputs is 30 ns.
The first situation is encountered when the 64×16 is employed in circuit switching, where 10 μs will be added to the call setup time. The second situation is applicable when the 64×16 switch is used in packet switching of packets longer than 10 microseconds. Here the control information can be pipelined. That is, while one packet is switched, a second packet header can be decoded and read in serially. Under these conditions, only 30 ns is needed to reconfigure for a new packet. A similar situation would be applicable in time switching.
The chip has been designed in 3-μm CMOS and operates in excess of 150 Mb/s. The chip is made up of 16 modules, each containing a 64×1 tree which is controlled with the parallel outputs of a 6-bit shift register located on top of the module. The 16 output drivers are at the bottom of the modules. The +5 V and ground lines are supplied from both sides with heavy on-chip busses to minimize voltage drops. These voltage drops produce crosstalk because they add to all outputs.
A summary of the technical features of the 64×16 space matrix is presented in the following specification table.
______________________________________Input Ports 64Output Ports 16No. Crosspoints 1024Bit Rate 150 Mb/sControl Serial-one input line, one output lineReconfiguration 1-10 μs to load control word 30 ns to executeDelay Input to Output 25 nsInput Levels(0 in.) 0 V(1 in.) +5 VOutput load 10 pFOutput Level(0 in.) 0 V(1 in.) +5 VPower Supply +5 VTechnology 3 μm CMOSPackage 108 pin grid arrayChip size 4.6 mm × 6.8 mmPackage Size 1.2" × 1.2"______________________________________
While there has been shown and described herein what are presently considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined by the appended claims.
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A broadband space switch matrix includes a parallel combination of individual switch modules each comprising a cascade of pass-transistor selectors, NAND gates, and inverters arranged into a multi-stage tree multiplexing configuration. The switching speed is increased by isolating each switching crosspoint from the stray capacitive loading in the matrix.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of semiconductor devices, and particularly to improved charge isolation techniques for image sensors.
BACKGROUND OF THE INVENTION
[0002] An image sensor generally includes an array of pixel cells. Each pixel cell includes a photo-conversion device for converting light incident on the array into electrical signals. An image sensor also typically includes peripheral circuitry for controlling devices of the array and for converting the electrical signals into a digital image.
[0003] FIG. 1 is a top plan view block diagram of a portion of a typical CMOS image sensor 10 . The image sensor 10 includes an array 11 of pixel cells arranged in columns and rows (not shown). The array 11 includes pixel cells 20 ( FIG. 2A ) in an active array region 12 and pixel cells 20 ′ ( FIG. 3 ) in a dark correction region 13 that are used for noise or dark correction. FIG. 2A is a schematic diagram of typical pixel cells 20 and FIG. 2B is a top plan view of a pixel cell 20 . The dark correction pixel cells 20 ′ have the same structure and operate in a similar manner to the active array pixel cells 20 . Accordingly, dark correction pixel cells 20 ′ can be configured as shown in FIG. 2A .
[0004] The dark correction region 13 is similar to the active array region 12 , except that light is prevented from reaching the photo-conversion devices of the dark correction pixel cells 20 ′ by, for example, a metal layer, a black color filter array, or any opaque material, depicted as 14 in FIG. 3 . Signals from dark correction pixel cells 20 ′ can be used to determine the dark correction level for the array 11 , which is used to adjust the resulting image produced by the image sensor 10 , by subtracting the signal generated by the dark correction pixel cells 20 ′ from the signal from the pixel cells 20 , which are used for image capture.
[0005] The pixel cells 20 illustrated in FIGS. 2A and 2B are typical CMOS four-transistor (4T) pixel cells. Typically, the pixel cells 20 are formed at a surface of a substrate, as generally shown in FIG. 3 . As is known in the art, a pixel cell 20 functions by receiving photons of light and converting those photons into electron charges. For this operation, each one of the pixel cells 20 includes a photo-conversion device 21 , which may be a pinned photodiode, but can be a photogate, photoconductor, or other photosensitive device. The photodiode photo-conversion device 21 typically includes an n-type photodiode charge accumulation region 22 and a p-type surface layer.
[0006] Each pixel cell 20 also includes a transfer transistor 27 , which receives a transfer control signal TX at its gate 27 a . The transfer transistor 27 is connected between the photodiode photo-conversion device 21 and a floating diffusion region 25 . During operation, the TX signal activates the transfer transistor 27 to transfer charge from the charge accumulation region 22 to the floating diffusion region 25 .
[0007] The pixel cell 20 further includes a reset transistor 28 , which receives a reset control signal RST at its gate 28 a . The reset transistor 28 is connected to the floating diffusion region 25 and includes a source/drain region 60 coupled to a voltage supply, V aa pix ) through a contact 23 . In response to the RST signal the reset transistor 28 is activated and resets the diffusion region 25 to a predetermined charge level through a supply voltage, e.g., V aa pix .
[0008] A source follower transistor 29 , having a gate 29 a coupled to the floating diffusion region 25 through a contact 23 , receives and amplifies a charge level from the diffusion region 25 . The source follower transistor 29 also includes a first source/drain region 60 coupled to the power supply voltage V aa pix , and a second source/drain region 60 connected to a row select transistor 26 . The row select transistor 26 receives a row select control signal ROW_SEL at its gate 26 a . In response to the ROW_SEL signal, the row select transistor 26 couples the pixel cell 20 to a column line 22 , which is coupled to a source/drain region 60 of the row select transistor 26 . When the row select gate 26 a is activated, an output voltage is output from the pixel cell 20 through the column line 22 .
[0009] Referring again to FIG. 1 , after pixel cells of array 11 generate charge in response to incident light, electrical signals indicating charge levels are read out and processed by circuitry 15 peripheral to array 11 . Peripheral circuitry 15 typically includes row select circuitry 16 and column select circuitry 17 for activating particular rows and columns of the array 11 ; and other peripheral circuitry 18 , which can include analog signal processing circuitry, analog-to-digital conversion circuitry, and digital logic processing circuitry. Peripheral circuitry 15 can be located adjacent to the array 11 , as shown in FIG. 1 .
[0010] In order to obtain a high quality image, it is important to obtain an accurate dark correction level for the array 11 . One problem encountered in the conventional image sensor 10 is interference to the signal produced by dark current pixel cells 20 ′ caused by photons entering the area 12 of the array containing active array pixel cells 20 , as shown in FIG. 3 , which is a cross-section taken across line X-X of FIG. 1 . Dark correction region 13 is shielded from incident light by a shield 14 . Longer wavelength light, such as near-infrared or infrared light at 800-1500 μm, may be reflected off the bottom 9 of the substrate 5 and generate carriers B that may also be absorbed by dark correction pixel cells 20 ′. In addition, when very bright light is incident on active array pixel cells 20 adjacent the dark correction region 13 , blooming can occur and excess charge from the active array pixel cells 20 , represented by carriers A, can travel to and be absorbed by dark correction pixel cells 20 ′ in the adjacent dark correction region 13 . In addition, excess charge from adjacent circuitry, e.g., peripheral circuitry 15 , can travel to and interfere with pixel cells 20 ′ in the adjacent dark correction region 13 .
[0011] These sources, and others, cause inaccurate dark correction levels. When enough carriers are absorbed by the dark correction pixel cells 20 ′, the signal generated by the dark correction pixel cells 20 ′ will be artificially high, such that the row in active array region 12 corresponding to each of these pixels 20 ′ will be over-corrected. The row in active array region 12 corresponding to each of the pixels 20 ′ will have a signal subtracted by a greater amount than actually needed for noise or dark correction. This causes inaccurate dark correction levels, resulting in row banding and distortion of the resultant image. Dark rows may appear in the image, even though they should appear bright in response to a bright subject.
[0012] Accordingly, it would be advantageous to have an improved image sensor with reduced interference on dark correction pixel cells.
BRIEF SUMMARY OF THE INVENTION
[0013] Exemplary embodiments of the invention provide a barrier for isolating the dark correction pixels of an image sensor. The barrier comprises a charge absorbing region in a substrate electrically connected to a voltage source terminal. The charge absorbing region is completely surrounds the dark correction region of a pixel array. The charge absorbing region absorbs carriers generated by lateral diffusion, near-infrared and infrared light reflected from the bottom of the silicon substrate, and charges from other sources that may diffuse into dark correction pixels. This absorbing region prevents carriers from being absorbed into the dark correction pixel cells and causing row banding and other image distorting effects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The foregoing and other advantages and features of the invention will become more apparent from the detailed description of exemplary embodiments provided below with reference to the accompanying drawings in which:
[0015] FIG. 1 is a top plan view block diagram of a conventional image sensor;
[0016] FIG. 2A is a schematic diagram of conventional CMOS pixel cells;
[0017] FIG. 2B is a top plan view of a pixel cell of FIG. 2A ;
[0018] FIG. 3 is a cross-section of the image sensor of FIG. 1 , taken across line X-X;
[0019] FIG. 4 is a top plan view block diagram of an image sensor according to an exemplary embodiment of the invention;
[0020] FIG. 5 is a cross-section of an embodiment of the image sensor of FIG. 4 , taken across line Y-Y;
[0021] FIG. 6 is a cross-section of another embodiment of the image sensor of FIG. 4 , taken across line Y-Y;
[0022] FIG. 7 is a cross-section of another embodiment of the image sensor of FIG. 4 , taken across line Y-Y;
[0023] FIG. 8 is a cross-section of another embodiment of the image sensor of FIG. 4 , taken across line Y-Y;
[0024] FIG. 9 is a cross-section of another embodiment of the image sensor of FIG. 4 , taken across line Y-Y;
[0025] FIG. 10 is a block diagram of a processor system according to an exemplary embodiment of the invention; and
[0026] FIG. 11 is a processor-based system according to an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof and illustrate specific embodiments in which the invention may be practiced. In the drawings, like reference numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized, and that structural, logical and electrical changes may be made without departing from the spirit and scope of the present invention.
[0028] The terms “wafer” and “substrate” are to be understood as including silicon, silicon-on-insulator (SOI), or silicon-on-sapphire (SOS) technology, doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. Furthermore, when reference is made to a “wafer” or “substrate” in the following description, previous process steps may have been utilized to form regions or junctions in the base semiconductor structure or foundation. In addition, the semiconductor need not be silicon-based, but could be based on silicon-germanium, germanium, or gallium-arsenide.
[0029] The term “pixel” or “pixel cell” refers to a picture element unit cell containing a photo-conversion device for converting electromagnetic radiation to an electrical signal.
[0030] Referring to the drawings, FIG. 4 depicts a top plan view of an image sensor 400 constructed according to an exemplary embodiment of the invention. The image sensor 400 includes an array 411 of pixel cells arranged in columns and rows. The array 411 includes pixel cells 420 ( FIG. 5 ) in an active array region 412 and pixel cells 420 ′ in a dark correction region 413 that are used for row-wise noise or dark correction while having additional protection against noise.
[0031] After pixel cells of array 411 generate charge in response to incident light, electrical signals indicating charge levels are read out and processed by circuitry 415 peripheral to array 411 . Peripheral circuitry 415 typically includes row select circuitry 416 and column select circuitry 417 for activating particular rows and columns of the array 411 ; and other peripheral circuitry 418 , which can include analog signal processing circuitry, analog-to-digital conversion circuitry, and digital logic processing circuitry. Peripheral circuitry 415 can be located adjacent to the array 411 . The configuration of image sensor 400 is exemplary only. Accordingly, image sensor 400 need not include peripheral circuitry 415 adjacent to the array 411 .
[0032] FIG. 5 is a cross-section of the array 411 taken across line Y-Y of FIG. 4 . The figure depicts a portion of the dark correction region 413 and a portion of the active array region 412 . Like dark correction region 13 ( FIGS. 1 and 3 ), the illustrated dark correction region 413 includes dark correction pixel cells 420 ′. Incident light is prevented from reaching the photo-conversion devices of the pixel cells 420 ′ in the dark correction region 413 by a shield 414 comprising, for example, a metal layer, a black color filter array, or any opaque material. While the dark correction region 413 is shown as having three dark correction pixels 420 ′ and active array region 412 is shown as having three pixels 420 , it should be noted that the illustration is a simplified cross-section and that the invention is not limited to having three pixels in each region. Both dark corrective region 413 and active array region 412 may have more or fewer pixels, as desired or suitable for the image sensor.
[0033] Protection against temporal noise caused by loose charge carriers described above is provided for the dark correction pixel cells 420 ′ by forming a structure or structures to absorb the carriers generated by lateral diffusion caused by blooming in active array pixel cells 420 or near-infrared or infrared light reflected off the bottom 409 of the silicon substrate 405 . In the embodiment depicted in FIG. 5 , there are two sets of structures for absorbing carriers. A first n-type implant 9 is formed under the dark correction pixels 420 ′ to provide an effective carrier absorbing region below the dark correction pixels 420 ′. The first n-type implant 9 will protect the dark correction pixels from being affected by the carriers that are generated by light that gets reflected off the silicon bottom 409 of the silicon substrate and by other sources. A second n-type implant 7 is formed on either side of (or around the perimeter of) the dark correction pixels 420 ′. An n-well 8 is also formed around the second n-type implant 7 so that the n-well 8 makes contact with the implant 7 . This configuration provides a continuous n-type region surrounding the dark correction pixels 420 ′ to provide an effective carrier absorbing region around the dark correction pixels 420 ′.
[0034] The second n-type implants 7 may be of higher doping concentration than the n-well 8 and the first n-type implant 9 and the n-well 8 may have higher doping concentration than the first n-type implant 9 . The first n-type implant 9 provides low-energy storage for carriers that are generated in the epitaxial layer beneath the dark correction pixels 420 ′. Since the second n-type implants 7 and n-wells 8 have a higher doping concentration than the first n-type implant 9 , the carriers will overflow from the first n-type implant 9 into the n-wells 8 , and into the second n-type implants 7 . From the second n-type implants 7 , the carriers are drawn out through a power source V cc that is connected to the second n-type implant 7 . The doping concentration of the first n-type implant 9 may be from about 1×10 15 atoms per cm 3 to about 1×10 17 atoms per cm 3 . The doping concentration of the n-well 8 may be from about 1×10 16 atoms per cm 3 to about 1×10 17 atoms per cm 3 . The doping concentration of the second n-type implant 7 may be from about 1×10 17 atoms per cm 3 to about 1×10 18 atoms per cm 3 . The doping concentrations may be modified and optimized to any concentration suitable for the configuration of the pixel array.
[0035] In one exemplary embodiment, the first n-type implant 9 is formed to a depth d of from about 0.8 μm to about 1.2 μm, more preferably 1.0 μm, and has a thickness t of about 0.5 μm. The n-well 8 may have a width w of about 0.5 μm. However, the first n-type implant 9 may have any depth and the n-well 8 may have any width suitable for the configuration of the pixel array.
[0036] In another embodiment of the invention, a first n-type implant 59 is formed under the dark correction pixel cells 520 ′ of image sensor 500 , as shown in FIG. 6 . As with FIG. 5 , it should be noted that the embodiment illustrated in FIG. 6 is not limited having three pixels in each region. Both dark corrective region 513 and active array region 512 may have more or fewer pixels, as desired or suitable for the image sensor. The first n-type implant 59 is formed under the dark correction pixels 520 ′. A second n-type implant 57 is formed on either side of (or around the perimeter of) the dark correction pixels 520 ′. An n-well 58 is formed under the second n-type implant 57 so that it makes contact with the second n-type implant 57 as well as the first n-type implant 59 . This provides a continuous n-type region surrounding the dark correction pixel cells 520 ′. The implants 57 , 58 , and 59 may be formed with a different doping concentrations as described above with respect to FIG. 6 , such that the second n-type implants 57 and n-wells 58 have a higher doping concentration than the first n-type implant 59 . Alternatively, they may be formed such that they have equal or lower doping concentrations. Because the implants 57 , 58 , and 59 are electrically connected, the carriers will flow from the first n-type implant 59 into the n-wells 58 , and into the second n-type implants 57 and from the second n-type implants 57 , since the carriers are drawn out through a power source V cc that is connected to the second n-type implant 57 .
[0037] Other exemplary embodiments are illustrated in FIGS. 7-9 . FIG. 7 illustrates an n-well region 68 being formed such that its bottom extends to the upper-most portion of a first n-type implant 69 . Unlike the embodiment of FIG. 6 , there is the n-well 68 does not have a surface that contacts a surface of the first n-type implant 69 .
[0038] FIG. 8 illustrates an n-well region 78 being formed such that its bottom extends to the lower-most portion of a first n-type implant 79 and the lower portion of n-well region 78 is in contact with the outer edge of n-type implant 79 . This forms a continuous n-type region around the dark correction pixel cells 720 ′ with an n-well 78 that has a surface that contacts a surface of the first n-type implant 79 .
[0039] FIG. 9 illustrates an n-well region 88 that intersects with a first n-type implant 89 in an intersecting n-type region 80 . This forms a continuous n-type region around the side and below the dark correction pixel cells 820 ′. The doping concentration of intersecting n-type region 80 may be the sum of the doping concentrations of n-well region 88 and first n-type implant 89 .
[0040] It is also possible to have spaced openings in the n-type region between the dark correction pixel cells and the bottom of the substrate. However, it should be noted that the dark correction pixel cells will be completely surrounded by a depletion region in spaces between n-type regions due to the power source V cc drawing carriers out through adjacent regions.
[0041] Because the dark correction pixels 420 ′, 520 ′, 620 ′, 720 ′, 820 ′ of FIGS. 5-9 , respectively, are completely surrounded by depletion regions and/or n-wells and n-type implant regions, they are isolated from any ground source since they are no longer in communication with the rest of the p-type substrate 405 , 505 , 605 , 705 , 805 . Therefore, a p+ contact 4 is provided to connect the dark correction regions 413 , 513 , 613 , 713 , 813 , to ground.
[0042] It should be noted that the configuration of the pixel cells 20 , 20 ′, 420 , 420 ′, 520 , 520 ′, 620 , 620 ′, 720 , 720 ′, 820 , 820 ′ is only exemplary and that various changes may be made as are known in the art and pixel cells of the image sensor may have other configurations. For example, although the invention is described in connection with four-transistor (4T) pixel cells 20 , 20 ′, the invention may also be incorporated into other pixel circuits having different numbers of transistors. Without being limiting, such a circuit may include five-transistor (5T) pixel cells, six-transistor (6T) pixel cells, and seven-transistor (7T) or more pixel cells. The 5T, 6T, and 7T pixel cells would differ from the 4T pixel cell by the addition of one, two, or three transistors, respectively, such as one or more of a shutter transistor, a conversion gain transistor, and an anti-blooming transistor. The circuit may also include three-transistor (3T) pixel cells.
[0043] Also, while the above embodiments are described in connection with p-n-p-type photodiodes as photosensors, the invention is not limited to these embodiments. The invention also has applicability to imagers employing other types of photo-conversion devices. In addition, while the above embodiments are described and illustrated has having p-type substrates and n-type implants, the invention is not limited to p-type substrates. The invention is applicable to n-type substrates having p-type implants as well.
[0044] FIG. 10 illustrates a block diagram for a CMOS imager 400 . The imager 400 includes a pixel array 411 , having an active array region 412 and dark correction region 413 . The pixels of each row in array 411 are all turned on at the same time by a row select line and the pixels of each column are selectively output by a column select line. A plurality of row and column lines are provided for the entire array 411 .
[0045] The row lines are selectively activated by the row driver 32 in response to row address decoder 30 and the column select lines are selectively activated by the column driver 36 in response to column address decoder 34 . Thus, a row and column address is provided for each pixel. The CMOS imager 400 is operated by the control circuit 40 , which controls address decoders 30 , 34 for selecting the appropriate row and column lines for pixel readout, and row and column driver circuitry 32 , 36 , which apply driving voltage to the drive transistors of the selected row and column lines.
[0046] Each column contains sampling capacitors and switches in a sample and hold (S/H) circuit 38 associated with the column driver 36 reads a pixel reset signal V rst and a pixel image signal V sig for each selected pixel. A differential signal (V rst −V sig ) is produced by differential amplifier 42 for each pixel. The signal is digitized by analog-to-digital converter 45 (ADC). The analog-to-digital converter 45 supplies the digitized pixel signals to an image processor 50 , which forms a digital image output.
[0047] FIG. 11 illustrates a processor-based system 1000 including an image sensor 400 of FIG. 4 having shielded dark correction pixel cells according to an embodiment of the invention. The processor-based system 1000 is exemplary of a system having digital circuits that could include image sensor devices. Without being limiting, such a system could include a computer system, camera system, scanner, machine vision, vehicle navigation, video phone, surveillance system, auto focus system, star tracker system, motion detection system, image stabilization system, and other system employing an imager.
[0048] The processor-based system 1000 , for example a camera system, generally comprises a central processing unit (CPU) 1060 , such as a microprocessor, that communicates with an input/output (I/O) device 1061 over a bus 1063 . Image sensor 400 also communicates with the CPU 1060 over bus 1063 . The processor-based system 1000 also includes random access memory (RAM) 1062 , and can include removable memory 1064 , such as flash memory, which also communicate with CPU 1060 over the bus 1063 . Image sensor 400 may be combined with a processor, such as a CPU, digital signal processor, or microprocessor, with or without memory storage on a single integrated circuit or on a different chip than the processor.
[0049] It is again noted that the above description and drawings are exemplary and illustrate preferred embodiments that achieve the objects, features and advantages of the present invention. It is not intended that the present invention be limited to the illustrated embodiments. Any modification of the present invention which comes within the spirit and scope of the following claims should be considered part of the present invention.
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A barrier for isolating the dark correction pixels from spurious charges within an image sensor. The barrier comprises a charge absorbing region in a substrate electrically connected to a voltage source terminal. The charge absorbing region completely surrounds the dark correction region of a pixel array. The charge absorbing region absorbs carriers generated by lateral diffusion, near-infrared and infrared light reflected from the bottom of the silicon substrate, and other sources. This absorbing region prevents carriers from being absorbed into the dark correction pixel cells and causing image correction distorting effects.
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BACKGROUND OF THE INVENTION
The present invention relates to a device for fastening footgear to a sports implement.
Fastenings associated with skis and suitable for temporarily associating footgear are currently known; in particular, fastenings which allow the rotation of the footgear at an axis which is transverse with respect to the tip in sports which require the rotation of the foot, are known.
Said sports may therefore be cross-country skiing, roller-skiing, Telemark skiing and mountain skiing.
Said known fastenings require rotation contrasting means, such as springs or elastically deformable parts made of plastics, accommodated inside the fastening or in adapted seats.
The disadvantage which can be observed in said known types of fastenings consists of the fact that in practice it is difficult to vary the rotation contrast.
It is in fact unthinkable, due both to operating difficulties and to difficulties in the assembly of the various components, to replace the springs; in those cases in which an adjusting of the springs is indeed provided, said adjusting can be achieved only by using specific tools or by using complicated systems which can increase the weight of the fastening.
The use of elastically deformable and replaceable parts forces the user to have a plurality of spares with different degrees of hardness; this solution is in any case extremely disadvantageous because the skier is forced to keep the parts, for example, in a pocket; the spare parts can thus be lost and will deteriorate in the course of time.
The known fastenings are furthermore not aerodynamically advantageous, and also not aesthetically pleasant.
SUMMARY OF THE INVENTION
The aim of the present invention is therefore to eliminate the disadvantages described above in known types by providing a device which allows to achieve an optimum and structurally simple elastic contrast and to vary, in a rapid and easy manner, the degree of contrast to the rotation of the footgear.
Within the scope of the above described aim, an important object is to provide a structurally simple device as well as easy and straightforward to use.
Another object is to provide a device which associates with the preceding characteristics that of being reliable and safe in use.
Still another important object is to provide a device which associates with the preceding characteristics that of increasing the aerodynamic characteristics of the assembly composed of the footgear and of the device for fastening said footgear to the sports implement.
Not least object is to provide a device which has low manufacturing costs.
The above described aim and objects, as well as others which will become apparent hereinafter, are achieved by a device for fastening footgear to a sports implement which can slide with respect to the ground, comprising means for achieving the oscillation between said footgear and said sports implement, characterized in that it comprises at least one distinct means for elastically contrasting the rotation of said footgear with respect to said sports implement, said at least one distinct means being actuatable by said footgear or by means of at least one interposed element which is associable therewith.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the invention will become apparent from the detailed description of a particular but not exclusive embodiment, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
FIG. 1 is a schematic side isometric view of the device applied to a ski;
FIG. 2 is a front isometric enlarged view of the device of FIG. 1;
FIG. 3 is a side sectional enlarged view of the device of FIGS. 1 and 2;
FIG. 4 is a side isometric view of an element for interposition between the footgear and the elastic contrast means of the device;
FIG. 5 is a side sectional view, taken along a longitudinal median plane, of the interposition element associated with the elastic contrast means and with footgear;
FIGS. 6 and 7 are side isometric views of the device applied to a roller-ski, showing respectively the roller-ski alone and the roller-ski engaged by an item of footgear;
FIGS. 8 and 9 are side isometric views of the device applied to a roller-skate, showing respectively the roller-skate alone and the roller-skate engaged by an item of footgear.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the above figures, in the particular embodiment, the reference numeral 1 indicates a ski for cross-country skiing, for mountain skiing or for Telemark skiing, to which a fastening device, not illustrated, is thus applied, said device being suitable for temporarily coupling the footgear 2 of the user at the tip 3 so as to allow its rotation during the practice of sports.
The fastening device comprises at least one means, generally indicated by the reference numeral 4, for elastically contrasting the rotation of the footgear 2 with respect to the ski 1.
Said means is constituted by a tip element 5 which embraces both the device for fastening the footgear to the ski and partially the tip 3 of the footgear.
Said tip element 5 can advantageously have, in the direction of the rear end 6 of the ski 1, a wing 7 for supporting the sole of the footgear 2, the width of said wing being approximately equal to that of said ski.
The tip element 5 furthermore has, along an axis which is transverse thereto, a slot 8, thus defining a band-like element which has a transverse perimetric edge, the band-like element being elastically connected at its ends to the tip element 5.
At least one slider 10 can be advantageously interposed at said slot 8.
Said slider is slidably associated, at the slot 8, so as to vary the contract offered during the forward flexing of the footgear, said flexing imposing a deformation to the tip element 5 and varying the interspace between the facing edges 11a and 11b of the slot 8. edges 11a and 11b of the slot 8.
Said slider 10 can thus have adapted pairs of tabs which slidably engage said edges 11a and 11b.
As an alternative, the slider 10 can have adapted projections which protrude from one of its sides and are selectively engageable at adapted holes 12 defined for example at the edge 11b.
It is furthermore advantageously possible to provide an element 13 for interposition between the footgear 2 and the means 4; said element 13 is constituted by a V-shaped monolithic part made of plastics which has an appropriately squared vertex 14 which can be arranged inside the tip element 5.
Means for engaging the sole 16 of the footgear 2 are provided at a first wing 15 which is arranged in contact with the wing 7 of the tip element 5 and is possibly articulated thereto; said means are constituted by an essentially L-shaped transverse lug 17, an end 18 whereof, directed toward the vertex 14, engages a complementarily shaped seat 19 defined on the sole 16 of the footgear 2.
A projection 21 is instead provided at the second wing 20 of the element 13 and abuttingly interacts with the transverse perimetric edge 9 of the tip element 5.
The device, according to the invention, therefore allows, by varying the position of the slider 10, to vary the elastic contrast of the tip element 5 to the rotation of the footgear 2 with respect to the ski 1.
It has thus been observed that the invention has achieved the intended aim and objects, and that it is possible to achieve in a simple manner an elastic contrast as well as a variation of the degree of rotation contrast, said variation being obtainable in a rapid and easy manner on the part of the skier.
The means 4 is furthermore structurally very simple and can act as fairing for the device for fastening the footgear to the sports implement, thus considerably increasing the aerodynamic characteristics thereof.
The means 4 may naturally be constituted by an element which is applied on the surface of the sports implement, said element being obtained by thermoforming or being screwed, glued or welded to the sports implement.
The means 4 can furthermore optionally be interposed between the region in which the fastening device is fixed to the sports implement, and an oscillating component which is articulated to said fastening device.
If the interposition element 13 is used, said element acts directly on the transverse perimetric edge 9 of the tip element 5.
The invention is naturally susceptible to numerous modifications and variations, all of which are within the scope of the same inventive concept.
The transverse perimetric edge 9, for example, can be a separate element applied on the tip element 5.
Likewise, the number and configuration and arrangement of the slots at the tip element may be any according to the specific requirements.
FIGS. 6, 7 show a device 104, according to the invention, applied to a roller-ski 101 and adapted to engage an item of footgear 102 as above described. the invention, applied to a roller-skate 201 and adapted to engage an item of footgear 202 as above described.
The materials and dimensions which constitute the individual components of the device may also naturally be the most pertinent according to the specific requirements.
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The device for fastening footgear to a sports implement, particularly to a cross-country ski or to a ski mounted on rollers or to a ski for Telemark skiing or to a ski for mountain skiing, has the peculiarity of including at least one means for adjustable elastic contrast to the rotation of the footgear with respect to the sports implement.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based on German Patent Application 10 2009 056 776.3 filed on Dec. 3, 2009.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention is based on a hydraulic system.
[0004] 2. Description of the Prior Art
[0005] Such hydraulic systems have a hydrostatic piston engine, whose volume flow is continuously variably adjustable via a valve controller. The hydrostatic piston engine is a plurality of pistons, movable back and forth periodically in cylinders, each piston defining one work chamber whose volume varies with the stroke of a piston and which can be made to communicate with a low-pressure connection via a low-pressure valve and with a high-pressure connection via a high-pressure valve. At least the low-pressure valves are actuated by means of an actuator, which in turn is triggered by a control unit. The valves must be capable of being switched highly dynamically, so that the work chamber can be very quickly blocked off or opened for a flow through it. To enable activating these valves as fast as possible, it is necessary upon actuation to have the largest possible attraction current flow through the actuator. The high actuation current produces a magnetic force in the actuator that is proportional to the current and that can mechanically actuate the valve. The high attraction current, however, leads to a corresponding power loss in the ohmic resistor of the actuator, which can heat the valve severely and impermissibly if triggering lasts a relatively long time. For maintaining the switching position of the valve, all that is needed in addition is a comparatively low maintenance current. Typically, the triggering of the valves is effected by means of a change in the voltage that is applied at the valve. A voltage change profile is specified in the control unit by software-based pilot control, and the pilot control in turn is based on experimentally ascertained data. Thus the voltage change profile includes an activation voltage profile for the attraction phase of the actuators as well as a reduced maintenance voltage profile for the maintenance phase.
[0006] The attraction current resulting from the activation voltage, and the maintenance current that varies with the temperature of the valve, can assume high values in an uncontrolled way. High current levels, or overswings in the current course, among other effects cause damage to electronic components or cable connections, for instance from overloading or thermal overheating. Moreover, imprecisions arise in the switching times of the valves, which depend strongly on the operating conditions at the time. That in turn is critical for the safety and sturdiness of the system
OBJECT AND SUMMARY OF THE INVENTION
[0007] It is the object of the invention to further develop a hydraulic system such that the valves switch with fast reactions and functionally safely, so that the expected functionality and safe operation of the hydrostatic piston engine is ensured under various operating conditions.
[0008] In the hydraulic system of the invention, the control unit includes a current regulating device, which triggers the actuators in current-regulated fashion.
[0009] By means of the apparatus according to the invention, the advantage is obtained that the actuator current is regulated, and thus from the detection of the actuator current course, the exact switching time is ascertained, and thus fast reaction times of the valve can be attained.
[0010] For perfect function of a valve-controlled hydrostatic piston engine, it is essential that errors such as short circuits, line interruptions, and overloading or overheating, be detectable reliably and quickly. Sources of error are quickly detected by read-out of the actuator current for a higher-order plausibility check with either the model value or the expected value, and permit fast counter-control for safe, sturdy operation.
[0011] By limiting the actuator current to a maximum value, it is unnecessary to design a control unit for higher currents, which leads to a cost saving. A regulated current also lead to correspondingly less lost heat, so that the components and possibly still other component groups combined in a housing are subject to less temperature stress.
[0012] Advantageously, the current-regulated triggering of the actuator is effected in the second time segment during the maintenance phase. In the actuated state of the valve, the maintenance current for maintaining the switching position is relatively slight. A relatively small regulated current also leads to correspondingly less thermal power loss. Reducing the power loss leads to structural compactness of the control unit. Regulating the actuator current can also be done during the first time segment or in both time segments. By precise monitoring of the current, both excessively high current levels and overswings in the current course are avoided. As a result of the regulation of the current course, the operation of the valve-controlled hydrostatic piston engine functions exactly as a result of the precise ascertainment of the switching points as a function of the current course, as well as safely, since overly high current levels and overswings in the current course are avoided.
[0013] In an especially preferred feature of the present invention, the current-regulated triggering of the actuator is effected by means of a clocked trigger voltage output by the control unit. This means that the attraction and/or maintenance voltage is varied in its effective voltage value by pulse width modulation. This has the advantage that the effective voltage value, based on a basic voltage such as the battery voltage, can be adjusted solely by pulse width modulation. Instead of the direct output of the clocked trigger voltage, the control unit can send an ON or OFF signal via a communications interface, and downstream electronic components convert these control commands into digital or PWM signals.
[0014] In an advantageous embodiment of the apparatus of the invention, for simple measurement of the actuator current, the current regulating device has a measuring resistor or shunt downstream of the actuator. The shunt is a low-impedance resistor, whose detected voltage drop furnishes the actual current value of the actuator.
[0015] Moreover, the current regulating device has a differential amplifier, which detects the voltage drop applied via the measuring resistor and furnishes a differential amplifier voltage which corresponds to the actual current value of the actuator.
[0016] Preferably, the current regulating device includes a current regulator, connected downstream of the differential amplifier, that compares the output signal of the differential amplifier, as an actual current value, with a set-point current value and controls the voltage supply to the actuator as a function of the differential current. An alternative to this purely electronic hardware version is a microprocessor with software stored in it for read-in of the actual current value, comparing it with the set-point value, and controlling or regulating the actuator current by evaluation of the differential current.
[0017] In an especially preferred feature of the present invention, the current regulating device has first switching elements and a pulse width modulator for triggering the switching elements. Current regulation can be attained economically, without software regulation, by means of minimum and maximum current regulation thresholds via a current regulator output signal, in that first switching elements are triggered via pulse counter modulation, as a function of the different current thresholds.
[0018] The PWM output signal of the current regulator can be carried to these switching elements, which for instance are field effect transistors.
[0019] If the current regulating device is implemented as an integrated circuit, further improvements are obtained with regard to diagnostic capabilities. In addition, the space required for the electronic components is reduced, and the thermal management is improved.
[0020] It may be advantageous to accomplish the communication within the overall control unit via a bus system. As a result, additional economies of space and error-free data transmission can be achieved.
[0021] Preferably, the control unit includes a voltage-increasing device, which generates a higher voltage from an operating voltage of the control unit, and that is supplied to the control unit. As a result, the attraction phase of the actuator can be shortened considerably.
[0022] In an advantageous feature of the apparatus of the invention, the voltage-increasing device has a boosting circuit, which particularly in response to a corresponding trigger signal charges a buffer memory to a higher voltage. The boosting circuit proves advantageous because in that case only one voltage source, the operating voltage, is required. Since the increased voltage is available only for at least the duration of the attraction phase, the energy consumption of the boosting circuit is quite low. Moreover, the buffer memory version is simple and favorable to implement.
[0023] Preferably, the buffer memory is switched to the actuator by second switching elements during the attraction phase. As a result, the increased voltage is switched to the actuator only for the duration of the attraction phase.
[0024] If the current regulating device, for regulating the current of the actuator, triggers the second switching elements during the attraction phase, then the actuator current can be regulated during the attraction phase as well.
[0025] Because the current regulating device, for regulating the current of the actuator, can trigger the first switching elements during the maintenance phase, the actuator current can be regulated during the maintenance phase as well.
[0026] The invention is not limited to a purely electronic hardware version. In general, the implementation or representation of the current regulation is dependent on the particular application. If inexpensive versions are of primary importance, if the demands from the outset are virtually static, and if hardware components without relatively expensive microprocessors and software are already available, then the purely hardware version is certainly to be preferred. However, if the demands are dynamic and have to be expandable, then implementation becomes more expensive, and possibly other or additional components (such as microprocessors and software) must be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings, in which:
[0028] FIG. 1 is a highly schematic illustration to explain the functional principle of a valve-controlled hydrostatic piston engine with a variable volume flow; and
[0029] FIG. 2 is a schematic circuit diagram of one embodiment of the current regulating device of the invention in a control unit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] First, the functional principle of a valve-controlled piston engine 1 , whose displacement/absorption volume is digitally adjustable (DDU), will be explained in conjunction with FIG. 1 . The piston engine described, in the exemplary embodiment shown, is embodied as an axial piston engine 1 of the swash plate type, and FIG. 1 shows a very highly simplified developed view of it. In the ensuing description, the piston engine 1 is described as a hydromotor; however, in principle the descriptions of the hydromotor pertain accordingly to a pump with an adjustable displacement volume.
[0031] In the schematic view in FIG. 1 , the piston engine 1 has a cylinder drum 2 , in which a plurality of cylinder bores 4 are embodied, in each of which one piston 6 is guided axially displaceably. Each of the pistons 6 , with the cylinder bore 4 , defines a work chamber 8 whose volume is independent of the stroke of the pistons 6 . These pistons are each braced via a respective piston shoe 10 on an obliquely positioned swash plate that is connected to a power takeoff shaft 12 . In the view in FIG. 1 , the control curve 14 formed because of the rotation of the swash plate is shown, which reflects the dependency of the piston stroke and thus of the volume of the particular work chamber on the angle of rotation. As shown on the right in FIG. 1 , each work chamber 8 communicates via an inlet valve 16 with an inlet line 18 common to all the work chambers 8 , and that line is subjected to system pressure or high pressure. This high pressure can be generated for instance via a pump 20 .
[0032] Each work chamber 8 furthermore communicates via an outlet valve 22 with an outlet line 24 , likewise common to all the work chambers 8 , which discharges into a tank 26 .
[0033] In the exemplary embodiment shown, the outlet valves 22 and the inlet valves 16 are each embodied as electrically openable and closable check valves. The inlet valve 16 , in its basic position shown, is prestressed into a closing position via a spring, not shown, and can be put into an open position by the supply of current to a magnet actuator 28 , so that the pressure medium can flow out of the inlet line 18 into the respective work chamber 8 . The outlet valve 22 , in its basic position shown, is prestressed in the open direction via a spring. By the supply of current to a magnet actuator 30 , this outlet valve 22 can be put into a closed position, in which the pressure fluid cannot flow out of the work chamber 8 . The triggering of the magnet actuators 28 , 30 is effected via a control unit 34 , by way of which various modes (full mode, partial mode, idle mode) can be set, so that the absorption volume of the piston engine 1 is continuously variably adjustable, and by suitable triggering of the valves 16 , 22 , the pulsation can be reduced to a minimum as well. In the exemplary embodiment shown, the triggering of the valves 16 , 22 is effected as a function of the rpm of the power takeoff shaft 12 , which is detected via an rpm pickup 36 and reported to the overall control unit 34 via a signal line. In principle, it is understood that still other characteristic data, such as the torque acting on the power takeoff shaft 12 , the absorption volume of the piston engine 1 , or the angle of rotation of the swash plate, can be taken into account in the triggering of the valves 16 , 22 .
[0034] FIG. 2 shows the basic construction of a control unit 40 . This control unit 40 includes, among other elements, a current regulating device 42 for regulating the current of a coil 44 of a solenoid valve, not shown in further detail.
[0035] The coil 44 is connected to ground 54 , on its end toward ground, via a measuring resistor 46 and a field effect transistor 48 , which transistor is switched on and off by means of an external trigger signal 50 , via a gate trigger circuit 52 . A differential amplifier 56 detects the voltage drop applied via the measuring resistor 46 and delivers the corresponding measured value, which is additionally conducted to the outside as a signal 58 , to a regulating amplifier 60 . This amplifier, taking into account an external set-point value signal 62 , triggers two field effect transistors 64 and 66 in such a way that the voltage, supplied via a diode 68 to the supply-voltage-side end of the coil 44 , corresponds to the desired set-point value.
[0036] The field effect transistors 64 and 66 are triggered in pulse width modulated fashion by the regulating amplifier 60 , so that the coil 44 either is connected via the field effect transistor 64 to the supply voltage or, via the field effect transistor 66 , contacts the ground terminal 54 .
[0037] FIG. 2 also shows a voltage-increasing device 80 . The voltage-increasing device 80 has a boosting circuit 82 , which on the input side receives an external set-point value signal 84 , and during that time generates a higher voltage U H =60 V, compared to the operating voltage U B =24 V. This higher voltage serves to charge a downstream capacitor 86 , which is connected to a ground terminal 88 . The voltage U H furnished by the capacitor 86 is dimensioned such that during the attraction phase, if a field effect transistor 90 , which is connected between the capacitor 86 and the coil and which is followed by a diode 92 connected in series with it, is made conducting as a function of a gate trigger circuit 94 . The gate trigger circuit 94 is triggered by an external set-point value signal 96 . The coil 44 is connected on the ground side to the voltage-carrying end of the capacitor 86 via a diode 98 . A freewheel diode 100 protects the field effect transistor 48 from voltage peaks upon being shut off.
[0038] In operation, the boosting circuit 82 , before the attraction phase of the valve, is supplied with an external set-point value signal 84 , so that the boosting circuit 82 , over a period of time predetermined by the duration of the signal 84 on the input side, charges the capacitor 86 with the higher voltage U H =60 V. During the attraction phase of the valve, the external set-point value signal 96 is applied to the gate trigger circuit 94 , which makes the field effect transistor 90 conducting, so that the coil 44 is subjected to the voltage U H applied to the capacitor 86 . During this attraction phase, the capacitor 86 discharges, with a time constant which is predetermined by its capacitance. The maintenance phase of the valve begins after the termination of the triggering of the gate trigger circuit 94 and the end of the resultant blocking of the field effect transistor 90 with the external set-point value signal 62 to the regulating amplifier 60 , so that during this maintenance phase, the coil is supplied with a regulated voltage via the field effect transistors 64 and 66 . The regulated voltage is a clocked voltage, which alternates between operating voltage and ground potential. It results from the pulse width modulated triggering of the field effect transistors 64 , 66 by the regulating amplifier 60 , whose trigger signals depend on the difference between the set-point current value and the actual current value of the coil 44 .
[0039] When the attraction current in the coil 44 is regulated, an output signal 63 of the regulating amplifier 60 leads to the gate trigger circuit 94 , so that the field effect transistor 90 is triggered, as a function of the actual current of the coil 44 and of the set-point value from set-point value signal 62 . As a result, excessively high currents are avoided during the attraction phase.
[0040] For the invention, a clocked trigger voltage is not compulsory for the current-regulated triggering of the actuators. To accomplish the fastest possible buildup of the magnetic field, the trigger voltage can be switched on or off in unclocked fashion accordingly in the attraction phase or at the end of the maintenance phase.
[0041] The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
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The invention relates to a hydraulic system, having a hydrostatic, valve-controlled piston engine with a plurality of valves actuatable by an actuator as a function of the motion of the pistons, and with a control unit for triggering the actuators, which is arranged for generating an electrical attraction current in a first time segment and a maintenance current in a second time segment. The object of the invention is for the valves to switch with quick reactions and function safely, so that the expected functionality and safe operation of the hydrostatic piston engine under various operating conditions is ensured. This is attained in that the control unit includes a current regulating device, which triggers the actuators in current-regulated fashion.
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BACKGROUND OF THE INVENTION
This invention relates to a hardware implemented system for inserting new instructions into a programmed set of instructions in memory in a functional sequencer. In a more specific aspect, the invention is related to a programmable logic controller having a keyboard module connected thereto in which there is provided a shift register for storage of new instructions and a counter in which the memory location at which the new instruction is to be placed is loaded and is counted down to zero beginning at the start of a memory cycle at which time the instruction in memory at the desired location is shifted into the shift register concomitantly with the shifting of the instruction from the shift register to memory followed by circulation through the shift register of all subsequent instructions stored in memory.
The present invention relates generally to devices known as programmable logic controllers. Controllers have heretofore been provided to control machines, processes, solenoids, motors, etc. Such controllers in general have a large number of output storage devices associated therewith, which devices are employed to connect power sources to machine elements or disconnect the same at times predicated upon conditions in the system and the relation of such conditions to a programmed set of instructions stored in a memory in the controller. Multiple relay installations have heretofore been employed to provide condition dependent control of machines or devices powered from alternating current sources. The installations have been made by guidance provided through electrical circuit diagrams in the form of ladder networks. Several attempts to solve problems encountered in simplifying installation procedures and operations are found in "Control Engineering", September 1972, page 45 et seq.
In the use of systems under direction of programmable logic controllers, it frequently becomes necessary to make physical changes in the system, adding more operative elements which must be controlled by the controller. In such controllers, or other functional computers, programmed sets of instructions ar stored within memory in response to which computations or sequences in the controller are directed. At times it, therefore, becomes necessary that the instruction set must be modified by adding an instruction somewhere in the programmed set.
In the computer art generally, the insertion of instructions in a programmed set has heretofore been carried out with software. The present invention provides a hardware insert function which allows more direct modification of the instruction set than with a separate software routine and in a manner uniquely and readily carried out without familiarity with conventional programming techniques.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a programming keyboard module connected to the controller for encoding instructions to be stored in a read/write memory in the controller. The keyboard module includes a shift register and a counter. A new instruction is manually loaded into the shift register. A memory location where it is to be placed is loaded into the counter. At the start of the memory cycle, the counter begins to count down. When the count reaches zero, the instruction that was already in memory at the designated location serially is shifted into one end of the shift register. At the same time, the new instruction is serially shifted out of the other end of the shift register into the designated memory location. Essentially the new and old instruction exchange places. The next instruction from memory then passes serially through the shift register while the word in shift register is shifted into the next memory location. The process is continued until all the instructions following the added instruction have been repositioned to the next memory location.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates a programmable timer installation;
FIGS. 1A and 1B illustrate the keyboard switching matrix of FIG. 1;
FIG. 2 illustrates a typical ladder network representing the system of FIG. 1;
FIGS. 3 and 4 illustrate the main section of the sequencer;
FIG. 5 illustrates the memory sections of the sequencer;
FIG. 6 illustrates certain of the control elements of the system of FIGS 3-5;
FIGS. 7-10 illustrate details of a programming unit employed herein;
FIGS. 11A-11E are timing diagrams;
FIG. 12 illustrates the relationships between FIGS. 3 and 4, between FIGS. 7-10, 11A-11C, and between FIGS. 13 and 14; and
FIGS. 13 and 14 illustrate the I/O units employed herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed specifically to a hardware implementation conveniently to modify an instruction set stored in memory in a sequencer. In a more specific aspect, it involves cooperation between the sequencer unit and the keyboard programming unit pursuant to which instructions stored in the sequencer memory may be serially read from memory through the programming unit and back to memory at addresses which are displaced by one address location from the address from which a given instruction was read.
FIG. 1
FIG. 1 illustrates a programmable logic controller 10 connected by way of a plug 398 and a multiconductor cable 399 to an I/O base unit 400 and thence by cable 399a to an I/O base unit 401 with a cable 399b extending in the direction of arrow 402 to additional I/O units that may be located at any desired points. The programmable controller 10 is a hard wired self-contained process sequencer and controller which is programmed from a plug-in input unit 600. Unit 600 is connected by way of cable 600a through a plug 600b to unit 10.
The I/O base 400 has a plurality of I/O connectors such as connector 409 to accommodate different circuit elements. I/O base 401 also has a plurality of I/O connectors such as connectors 411 and 414. The connectors are used, for example, in the control of an X/Y table 404. A motor 405 drives table 404 along one axis. A motor 406 drives table 404 along another axis. A limit switch 407 is positioned to be actuated when physically engaged by table 404. Motor 406 is connected by conductors 408 to output connector 409 and the I/O base 400. Switch 407 is connected by conductors 410 to input connector 411 on T/O base 401. A push-button switch 412 is connected by conductors 413 to input connector 414 on base 401.
Programmable controller 10 is used, for example, to energize motor 406 only when both switches 407 and 412 are closed. Such action would be in response to control states stored in a memory in unit 10. The memory in unit 10 may be loaded with the desired control states by way of the input unit 600.
I/O base 400 in this example provides eight input connectors 400a and eight output connectors 400b. Similarly, I/O base 401 provides eight input connectors 401a and eight output connectors 401b.
FIG. 2
The system operates in response to instruction voltage states loaded in the language of ladder networks normally employed in the wiring of power control systems. For example, FIG. 2 illustrates a typical ladder network wherein limit switch 407 and push-button switch 412 are connected in series with motor 406 between power conductors 415 and 416 which are included in power cable 397 leading to base 400, FIG. 1. In a similar manner, motor 405 is connected in series with like control elements between lines 415 and 416. A third circuit connected across lines 415 and 416 may comprise three switches in parallel leading to a timer 417 and a control relay 418 where the timer is operative when any one of the switches connected thereto is closed.
In the embodiment of the invention which is described herein, 256 output elements like element 409, and 256 input elements like elements 411 and 414, may be accommodated. The system illustrated in FIG. 1 provides for storing instructions for implementing many paths in a ladder diagram. The embodiment is exapandable to accommodate many more elements included in a system represented by a ladder diagram. This is accomplished by using in a unique manner a nonaddressed push down storage stack for temporary storage of intermediate results of programmed manipulations which will operate equally well with Boolean equations which may be broken into subgroups and each subgroup separately stored in a push down stack and thereafter combined to produce final results of the Boolean relationship. While only simple ladder elements are illustrated in FIG. 2, the system illustrated in FIG. 1 is versatile in that an almost unlimited number of rungs may be accommodated in the ladder network with unlimited number of elements in a given rung or line.
The construction employed for controller 10, the I/O bases 400 and 401 and the control module 600 will now be described. It will be understood that the unit 600 is to be employed only to program a controller. In operation, the plug 600b would be inserted only while the desired ladder network is being entered into controller 10. Thereafter, plug 600b would be removed and unit 600 would be available for use for programming additional controllers located elsewhere.
PROGRAMMABLE CONTROLLER 10 - FIGS. 3-6
Programmable controller 10 illustrated in FIGS. 3-6 has the following distinct functional sections.
Counter -- Data Register -- FIGS. 3 and 4
Units 12--15 serve as serial I/O counters when operating in a serial I/O mode and as memory instruction registers when operating in a run mode. They operate in conjunction with an image register 20 as will hereinafter be explained.
Bit and Instruction Counter -- FIGS. 3 and 4
Units 36-38 are interconnected to form a bit and instruction counter for synchronizing and controlling the sequencing operations in the unit.
Scan Cycle Counter -- FIG. 3
A counter 35 serves to count scan cycles that have been completed in order to assist timing operations as may be required when timing units such as unit 417, FIG. 2, are to be employed.
Processor -- FIG. 3
Units 61, 62 and 63 serve as primary processor elements. Element 61 is a main decoder and processor ROM. Unit 62 is a timer-counter processor ROM. Unit 63 is a timer-counter state storage unit.
Sync Latch -- FIG. 3
Through a sync latch 11, a start pulse is transmitted to initiate each cycle of the controller. Controller 10 works normally in conjunction with devices powered from 110 volt lines 415, 416, FIG. 2. Controller 10 operates through a complete cycle within the time limits of each half cycle of the power voltage. An input sync pulse applied to terminal 11e of sync latch 11 is caused to occur at the peak of each half wave of the power voltage.
Upon generation of each sync pulse, signals indicating the states of all of the control elements in the ladder network, such as switches 407, 412, etc., FIG. 2, are read into the controller and stored in the image register 20 by way of a data input AND gate 17. After reading data in, newly generated control states are fed out of controller 10 by way of cable 399, one circuit of which leads from data out NAND gate 18. Thereafter, all instructions in memory 25-28 or 30-33, FIG. 5, are reviewed and new output data is created. The cycle is thus completed and the controller waits for the next peak in the power voltage to initiate another controller cycle.
Output data from gate 18 is stored in shift register memories in units 400, 401, etc., FIG. 2. Such memories, in the form of dual output registers, store output data which establishes control conditions for a given time interval as will be explained in connection with FIGS. 13 and 14. During such interval, new output data is stored in the other part of the dual output register.
Control is shifted from data in one half of the output register to data in the other half of the output register upon each zero crossing of the power voltage waveform.
Push Down Stack - FIG. 3
Unit 80 is a one bit word width push-down stack. Results of logical calculations made by other parts of the controller are stored in this push-down stack. The results may be retrieved at will in the opposite order to which they were stored. The length of the push-down stack 80 in a practical sense may be unlimited, with adequate units connected in tandem to accommodate any reasonable number of results to be stored. The intermediate results in the sequencing operations can be retrieved from the push-down stack 80 for combination with other sequencing calculation results.
Memory Section - FIG. 5
The memory section includes a random access memory (RAM) comprising four RAM units 25-28 and a programmable read only memory (PROM) comprising PROM units 30-33. Each of the RAMs 25-28 has a storage capacity of 1,024 bits with ten input control lines so that one bit may be read out at a time. The PROMs 30-33 have eight input control lines for outputting four bits in parallel at any time. RAMs 25-28 thus provide for the storage of 256 sixteen bit instructions. The instructions may be stored in RAMs 25-28 by use of unit 600 when NAND gate 24 is enabled. The line 23 is the memory data input line and must be enabled for flow of data to RAMs 25-28. Alternatively, 256 instructions may be stored in PROM units 30-33.
It will be noted that in FIG. 5 both the RAM units 25-28 and the PROM units 30-33 are shown in place. The RAM 25 and PROM 30 are actually connected for parallel operation and thus occupy the same position in the system. One or the other but not both would be used. The same is true of RAM 26 and PROM 31, of RAM 27 and PROM 32, and of RAM 28 and PROM 33. Thus, while redundancy is actually shown in FIG. 5, only four memory units will be employed in the embodiment here described with any desired combination of RAMs and PROMs.
The instructions storedin RAMs 25-28 may be altered by use of unit 600 in the ordinary course of operation to insert new instructions or change an existing instruction. In contrast, PROMs 30-33 are fixed and cannot be altered through use of unit 600. In the case of both RAMs 25-28 and PROMs 30-33, instructions are read out in the form of 16 one-bit control states and are read out serially by way of a gate 34.
Before describing the system in any further detail, a gross description of the desired operation will be briefly presented.
The system is sequenced through three modes, (a) wait, (b) serial I/O and (c) run.
The wait mode: The system is quiescent awaiting the next occurrence of a peak in the a.c. 60 cycle power voltage. When a peak occurs, a sync pulse if generated which initiates operation, each cycle being completed prior to the occurrence of the next peak.
The serial I/O mode: This mode is initiated by the appearance of the sync pulse. Three separate stages are involved in the serial I/O mode. During the first stage, the state of all of the input units (407, 412) on units 400, 401, FIG. 1, are read in and stored in image register 20. In the particular embodiment here described, image register 20 has 1,024 bits of storage. The input section of the image register 20 is limited to 256 bits. Therefore, as many as 256 input units can be accommodated and the states thereof read into image register 20.
During the second stage, a serial out operation takes place wherein the 512 bits centrally stored in image register 20 are read out serially. The 512 central locations are used to store flags used internally in the system and made available to any external device that may require use of such flags. No specific use is described herein but storage of such flags is part of operation and read out thereof is part of the second stage function. They are included in the serial I/O mode as an intermediate series of steps.
During the third stage, the last 256 bits in the image register 20 are read out and transmitted over cable 399, FIG. 1, for storage in units 400, 401, etc.
The information stored in the last 256 bits of register 20 is information produced during the previous cycle of operation and more particularly during the run mode of the previous cycle.
The run mode: In the run mode, instructions stored in memories 25-28 and/or 30-33 are executed by the system on the input data stored in the first 256 bits of the image register 20.
At this point it will be helpful to understand that in each of the units 400, 401, etc. there is included a parallel input serial output shift register having one bit for each input connector (411) associated with a given base, such as base 401. There is also included a serial input parallel output shift register, each having one bit for each output connector (409) associated with a given base, such as base 400. The shift registers in bases 400, 401, etc. are interconnected in tandem so that during the serial-in portion of the serial I/O mode, the states of all of the input units (407, 412) are read in serially through cable 399 into the image register 20. Thus, the bits stored in the first 256 locations in image register 20 represent the states of control elements such as switches 407 and 412, FIG. 2, at the instant that the serial I/O portion of the scan cycle takes place. At the end of the serial I/O mode, the states to which the output units, such as motors 405 and 406, are to assume are read out into the serial-in, parallel-out registers and there stored for application through control means to be applied to the output units.
With the foregoing understanding, details of the construction of the system shown in FIGS. 3-6 will now be described, following which the operation will be set out.
Controller -- FIGS. 3 and 4
A NAND gate 11a in latch 11 is connected by way of line 81 to the clear input terminals of each of the units 13-15 and to the input of an RUN flip-flop 21. A pulse on line 81 is a cycle enable pulse initiating operation of the system at each peak of the power voltage.
The Q output of flip-flop 21 is connected by way of line 82 to the load input terminal of each of the units 12-15 and to the control terminal of AND gate 17. The Q output of unit 21 is connected by way of line 83 to the control terminal of an AND gate 17a. Gates 17 and 17a are connected to the inputs of a NOR gate 17b which leads by way of inverter 17c and AND gate 17d to the data input terminal of the image register 20. The data output terminal of register 20 is connected by way of line 84 to a data input terminal A of the main decoder and processor ROM 61 with the output on line 85 leading back through the data input terminal of AND gate 17a as well as to the D input terminal of a D flip-flop 86 which will be referred to herein as the active indicator or AI. The Q output terminal of AI flip-flop 86 is connected by line 87 to the data input terminal of push-down stack 80 as well as to the input terminal B or ROM 61.
Returning now to the RUN flip-flop 21, the Q output terminal is connected by way of line 83 to an enable input terminal and to a clear input terminal of each of counters 36, 37 and 38. The carry output terminal of counter 36 is connected by way of AND gate 88 to a second enable terminal of counter 37 whose carry output is connected by line 89 to a second enable terminal of counter 38. The carry ouput line of counter 39 is connected by way of line 52 to a second enable terminal of counter 36 and to a NAND gate 90. The carry output terminal of counter 36 is connected by way of an exclusive OR gate 91 to a second input of NAND gate 90. Exclusive OR gate 91 has a control line 92 leading from a flip-flop 93, FIG. 6, over which there is supplied a control voltage which is a time gate of length during which a word may be written into any one of the four RAMs 25-28. NAND gate 90 has a third input line 94 to which there is supplied a control voltage from a flip-flop 95, FIG. 6, to provide a SERIAL IN gate pulse. NAND gate 90 is connected to the load terminal of counter 39. The clear terminal of counter 39 and of flip-flop 21 are supplied from a NAND gate 21a.
The output lines K2, KQD, K3-K14 are lines which are included in a cable 40 leading to the sites of RAMs 25-28 and PROMs 30-33. Output line K14 from counter 38 is connected by way of inverter 96 to the clock input terminal of counter 35. The output of inverter 96 is connected by way of inverter 97 and by parallel conductor 98 to the two inputs to NAND gate 11d. The output of NAND gate 11d is a SCAN COMPLETE signal applied to NAND gate 11b to reset the latch 11 in ccondition for receipt of the next sync pulse applied to the input terminal 11e.
An oscillator 50 is connected by way of line 51 to the clock input terminal of counter 39. Oscillator 50 operates at approximately 8 mHz. It is shown in more detail in FIG. 6.
The output lines from the counter-register units 12-15 are identified as lines BO-B15, there being sixteen output bits. Lines BO-B7 are connected by way of exclusive OR gates 100-107, respectively, to the AO-A7 inputs of image register 20. The second inputs of exclusive OR gates 100-107 are connected to line 108 which, when high, inverts the adresses to register 20. The clock input terminals of each of the units 12-15 is supplied from a NAND gate 109.
States on lines B8-B11 from register 13 are employed as control-timing functions as will be described in connection with FIG. 11A.
Lines B12-B15 are connected to four input terminals E-H, respectively, of ROM 61 to apply the desired OP codes to processor 61. ROM 61 has two terminals XX which are enable terminals. The upper terminal X is connected to the output of a NAND gate 120 whose output is also connected to an enable terminal S/L (shift/load) of four bit counter 63 and, by line 121 to an inverter 122 which leads by way of a NAND gate 123 to the clock input terminal of push down stack 80. The second enable terminal X of ROM 61 is supplied from the bit 0 line 124.
Data input terminal A or ROM 61 is connected by way of line 84 to the output of the image register 20. Input line D is supplied by way of the carry (CRY) line 125 leading from counter 35. B input terminal is connected by way of line 87 leading from the Q terminal of the active indicator flip-flop 86. The C input terminal is connected by way of line 127 from the output terminal of push down stack 80.
Processor ROM 61 has four output terminals Y1-Y4: (i) Terminal Y1 is connected by way of line 85 to the D input terminal of the active indicator 86 and to AND gate 17a; (ii) Terminal Y2 is connected by way of line 128 to one input of each of NAND gates 123 and 129. The output of NAND gate 129 is connected by line 130 to the clock input terminal of active indicator 86. NAND gates 123 and 129 are each supplied by the output of a NAND gate 131 whose inputs are supplied by way of a write pulse line 132 and bit 0 line 124; (iii) Terminal Y3 is connected to AIQ(MCR or JUMP) line 133; and (iv) Terminal Y4 is connected by way of increment line 134 to the input pin 6 of the four bit counter 63.
ROM 62 has four output terminals Y1-Y4: (i) Terminal Y1 is connected to line 85 and thus parallels the Y1 output terminal of ROM 61; (ii) Terminal Y2 of ROM 62 is connected by way of line 135 to the data input terminal of register 12; (iii) Terminal Y3 of ROM 62 appears on memory write data line 23; and (iv) Terminal Y4 of ROM 62 is connected to the D input terminal of a flip-flop 137 which serves as a carry flip-flop for processor 62.
The Q output terminal of flip-flop 137 is connected to the D input terminal of ROM 62. The A input terminal of ROM 62 is supplied by a line 138. The B input terminal of ROM 62 is supplied by the B0 output of register 15 as above described. The C input terminal of ROM 62 is supplied by WAF line 139. The input terminals H, G and E of ROM 62 are connected from the A, B and C output terminals, respectively, of counter 63. The F input terminal of ROM 62 is supplied by the EF line 140 which results from NANDing counter outputs K4, K5 and K6 in NAND gate 136. The D output terminal of counter 63 appears on a D output line 141 which leads FIG. 5. The enable terminal P of counter 63 is supplied by way of a NAND gate 142, one terminal of which is supplied by way of ROM line 143. The other input to NAND gate 142 is supplied by external load line 144. The external load line 144 is also connected to the enable terminal CE of image register 20.
It will be noted that the gates clock line 110 is connected to the clock input terminals of each of the registers 12-15, to the clock input terminal of the carry register 137, and to the clock input terminals of counters 36-38.
A write pulse line 132 is connected to one of the three inputs of NAND gates 109 for controlling application of clock pulses to line 110.
Data read from memories 25-28 and/or 30-33 appear on memory read data line 146 which is connected to AND gate 147. The output of AND gate 147 is connected by way of NOR gate 148 and line 149 to the input of an AND gate 150. The second input of AND gate 150 is supplied from a NAND gate 151, one input of which is supplied from the B output terminal of counter 63. The other input of NAND gate 151 is supplied from the A output terminal of counter 63 by way of an inverter 152. The output of AND gate 150 is applied to NOR gate 153 whose output is connected by way of inverter 154 to the line 138 which leads to the A input terminal of ROM 62.
The output of NAND gate 151 is also connected by way of inverter 155 to one input of an AND 156. The second input of AND gate 156 is derived from the output line 127 leading from the push down stack 80. The output of AND gate 156 is then connected to the second input of NOR gate 153.
A bit zero delay line 157 is connected to terminal 2 of counter 63.
A battery low line 158 is connected to one input of NAND gate 18 which is in the flow path of data out of the image register 20. The third input to NAND gate 18 is supplied by way of the start up line 159.
Lines A8 and A9 are connected to inputs 9 and 10 of image register 20. An image register gated write pulse (IRGWP) line 160 is connected to the R/W input terminal of image register 20.
Serial data output line 165 extends by way of an inverter 166 from NAND gate 18.
Counter output lines K3-K14 lead to FIG. 5. Register output lines B0-B11 lead to FIG. 6 along with lines K2 and KQD. Lines K0 and K1 are not used.
A NAND gate 166 supplies an I/O clock signal on line 167. The inputs to NAND gate 166 comprise a Q output of flip-flop 21 and the gated clock signal on line 110 leading from NAND gate 109.
The Q output of flip-flop 21 is connected by way of inverter 168 to the run line 169 which leads to the program panel 600.
The output of NAND gate 11b is connected by way of inverter 170 to the cycle enable line 171.
It was previously noted that external load line 144 was connected to AND gate 147. Line 144 is also connected by way of inverter 172 to one input of an AND gate 173. The output of AND gate 173 is connected to NOR gate 148. The second input of AND gate 173 is supplied by the program panel data input line 174.
FIG. 5
FIG. 5 illustrates the main memory of the system. It includes the previously identified RAMs 25-28 and PROMs 30-33. Again it will be noted that in this embodiment four memory units are employed. The four may comprise any combination of units 25 and 30, units 26 and 31, units 27 and 32, and units 28 and 33. One set of four would consist of units 25-28. A different set would consist of units 25-27 and unit 33. Another would comprise units 25, 26, 32 and 33, etc.
Counter output lines K4-K14 are connected to address input terminals of the memory units 25-28 and 30-33. Lines K3-K12 are connected to the A0-A9 inputs of units 25-28. Lines K5-K12 are connected to the A0-A7 address inputs of units 30-33. Lines K13 and K14 are connected to the A and B inputs of a data selector 175. Selector 175 has output select lines 180-183 which enable PROMs 30-33, respectively. Data selector 177 has output enable lines 185-188 which enables units 25-28, respectively. Units 175 and 177 form a single unit known as a demultiplexer. A muliplexer unit 190 has inputs A and B connected to lines K3 and K4, respectively. Each of units 30-33 has four output lines Y1-Y4. Output lines Y1-Y4 are connected parallel to a four output line bus 191 leading to inputs IC0-IC3 of multiplexer 190. A single output line 192 then leads to a flip-flop 193, the clock input terminal of which is supplied by line K2. The output line 194 from flip-flop 193 is connected to output gate 34 whose output leads to the memory read data line 146 and by way of inverter 196 to the memory read data line 197. Data on line 146 is employed by sequencer 10. Data on line 197 is employed by program panel 600.
The data output line 198 leading from the data output terminals of all of the memory units 25-28 is connected to the second input of NAND gate 34.
FIG. 6
FIG. 6 illustrates logic elements employed to produce control states and timing states for operation of sequencer 10 as thus far described.
A master control relay and jump unit 210 includes two four bit counters 211 and 212. Lines B0-B3 from register 15, FIG. 4, are connected to counter 211. Lines B4-B7 are connected as inputs to counter 212.
Counters 211 and 212 are up/down counters. The output of counter 211 is connected to the down input terminal of counter 212. The output of counter 212 is connected to the clear input terminal of a flip-flop 213 and to the preset input terminal of a flip-flop 214. The Q output terminal of flip-flop 213 is connected to the clock input terminal of flip-flop 214 and to one input of a NAND gate 215 as well as to the load terminals of counters 211 and 212. The Q output terminal of flip-flop 213 is connected to one input of a NAND gate 216, the output of which is connected to the D input terminal of flip-flop 213. The Q output terminal of flip-flop 213 is also the counting output line 217. The line B14 is connected to the D input terminal of flip-flop 214. The cycle enable line 171 is connected to the clear terminals of counters 211 and 212. The sequencer output line 128 leading from the Y2 terminal of ROM 61 is connected to one input of NAND gate 215 and to one input of a NAND gate 218. The second input of NAND gate 218 is supplied from the Q output terminal of a flip-flop 95. The Q output terminal of flip-flop 95 supplies the signal on serial in line 94. The clear input terminal of flip-flop 95 is supplied by the END CYCLE signal on line 163 which is the output of NAND gate 21a, FIG. 3.
MCR + JUMP unit 210 serves to provide an output signal at the Q terminal of flip-flop 213 which controls whether or not the system is operating in a jump mode or a master control relay (MCR) mode. Flip-flop 213 indicates MCR or JMP mode whereas flip-flop 214 indicates JUMP only. If the Q terminal of flip-flop 214 is low, then the system is operating in a jump mode.
The Q output of flip-flop 214 is connected to one input of a NAND gate 220, the output of which appears on line 160. The clock input terminal of flip-flop 95 is supplied to the B8 line. The MCR + JUMP unit 210 thus is comprised of counters 211, 212, flip-flops 213, 214, flip-flop 95, and gate 220 as major components to generate the signals on lines 160 and 217.
Input line B8 is connected by way of an inverter 221 to one input of a NAND gate 222. The output of NAND gate 222 is connected to one input of NAND gate 223 which supplies the second input to exclusive OR gate 203. The second input to both of NAND gates 222 and 223 as well as exclusive OR gate 202 is supplied by way of the B11 line. The third input terminal to NAND gate 222 is supplied by way of the B10 line. The second input to the exclusive OR gate 203 is supplied by the B9 line.
A run line 82 is connected to one input of the NAND gate 200. The output of NAND gate 200 is connected by way of inverter 201 to the INVERT-ON-ONE line 108. The second input of NAND gate 200 is supplied by way of the B8 line which is connected through an exclusive OR gate 202 to NAND gate 200. The output of the exclusive OR gate 202 appears on the A8 line. The A9 line signal is produced at the output of an exclusive OR gate 203 which is also connected as the third input to NAND gate 200.
The circuit leading to WAF line 130 includes an AND/OR invert gate 224, an inverter 225, flip-flop 226 and inverter 227. This circuit serves the purpose of multiplexing the AIQ signal on line 87 and the signal on the B15 line. The B15 line is connected to the D input of flip-flop 226. The bit 0 pulse line 126 is connected to the clock terminal of flip-flop 226. The D line leading from counter 63 is connected to the input of inverter 227 and thence to preset terminal of flip-flop 226. The Q output terminal of flip-flop 226 is connected to one AND gate of unit 224. The B output terminal from counter 63 is connected to inverter 225 whose output is connected to the second AND gate of unit 224 and to the second terminal of the first AND gate of unit 224. The AIQ line 87 is connected to the second AND gate of unit 224.
A write pulse on line 145 is produced by use of flip-flop 230 which has the KQD line from counter 39 connected to the D input terminal and the K2 line from counter 39 connected to the clock terminal. The Q output terminal of flip-flop 230 is connected to the write pulse line 145.
The Q output terminal of flip-flop 230 is connected to a third input of NAND gate 220 and to one input of a NAND gate 231. The output of NAND gate 231 is the CPU3 line 232 which is employed in unit 600, FIG. 1. Line 233 leading from the carry output of counter 36 is connected to the D input terminal of a flip-flop 237. The clock input terminal of flip-flop 237 is supplied by the gated clock output line 110. The Q output of flip-flop 237 is connected to the second input terminal of NAND gate 231. The third input terminal of gate 231 is supplied by the KQD output of gate 39 by way of inverter 238.
The outputs A and B from unit 63, together with the external load line 144, are employed to generate a RITED signal on line 239 and a ROM LOAD signal on line 143. Lines A and B are connected by way of an exclusive OR gate 240 and an inverter 241 to line 143. The output of inverter 241 is also connected to one input terminal of a NAND gate 242, the second input of which is the external load line 144. The output of NAND gate 242 is connected to one input of the NAND gate 243, the output of which is the RITED line 239.
The output of NAND gate 243 is connected by way of line 239a to the D input terminal of flip-flop 93. The clock input terminal of flip-flop 93 is supplied from the Q output terminal of flip-flop 237. The Q output of flip-flop 93 is the RITEFF line 92 which is connected to the second input of NAND gate 243. The Q output terminal of flip-flop 93 is the complement of the signal on line 92a.
The Q output of flip-flop 237 also appears as the BIT 0 output line 124. The BIT 0 signal on line 124 is provided as a BIT 0 DELAY signal on line 157 by use of a flip-flop 244. The D input terminal of flip-flop 244 is connected to the Q output terminal of flip-flop 237. The clock input terminal of flip-flop 244 is supplied by the K2 line leading from counter 39. The Q output terminal of flip-flop 244 is then connected to the output line 157 and by way of line 157a to the clock input terminal of flip-flop 213.
Provision is made in this system for anticipated failure of the power supplying the system and the operative elements controlled by unit 10. The point of concern has to do with the battery 250 which supplies power to the RAM memory power circuit represented by block 251. The RAM memory circuits are those illustrated as units 25-28 of FIG. 5. In the circuit illustrated in FIG. 6, battery 250 is charged from a power supply deriving its energy from an a.c. power line. Charging current obtained, supplied at terminal 252 passes by way of a transistor 253 to the battery 250. The circuit operates such that if the alternating current power fails and the voltage of battery 250 is below a preset level, then gate 18 of FIG. 4 is inhibited from reading out any of the data to the units 400, 401, etc. and all of the output elements in units 400 and 401 would be forced to a safe condition pending reestablishment of the alternating current power.
The voltage of battery 250 is compared in an amplifier 254 against the reference voltage on line 255. When the power fails, the voltage on line 255 goes to zero. If the voltage across battery 250 is not above a preset level represented by the voltage on line 255, then the output on line 255a goes high which turns on a light emitting diode 256 to signal low battery voltage. Line 255 is connected to one input of a NAND gate 257 which with gate 258 forms a latch. The output line 259 from latch 257, 258 is connected by way of gate 260 which leads to batt low line 158.
A power on clear circuit 261 includes a Schmitt trigger NAND gate 262 which is connected by way of inverter 263 to a second input of NAND gate 258. The input to the Schmitt trigger 262 is supplied from the terminal 264. A capacitor 265 charges up slowly when the power having failed comes back on. The charging current flows through a resistor 266. The power on clear circuit 261 forces the output terminal of gate 258 high which turns the transistor 253 off and thus prevents battery 250 from being charged momentarily or at least long enough that the comparison can be made to determine whether or not battery 250 is dead. If the battery is dead, the system will not be permitted to be in operation automatically and unattended following restoration of the power to the system.
A start up switch 270 is adapted to connect the input of an inverter 271 to ground or the input of an inverter 272 to ground depending upon its position. When the input to inverter 271 is grounded, the START UP line 159 is also grounded. This prevents data from passing through gate 18. When switch 270 is in the other position, grounding the input to inverter 272, line 159 is high which serves to enable gate 18.
An output line 273 is provided for transmitting a gated clock signal PPGC to unit 600, FIG. 1. Clock signal PPGC is provided at the output of a NAND gate 274 having one input connected to the Q terminal of flip-flop 93, a second terminal connected to the gated clock line 110 which passes through an inverter 275. The third input to gate 274 is the RUN line 82.
In this embodiment, processor 61 has been described as a read only memory (ROM). The particular unit employed was of the type H PROM 1-1024-5B hereinafter more fully identified in Table VII. ROM 61 was programmed in accordance with the following table.
TABLE I______________________________________PROM 61Hex Outputs Hex OutputsAdd. Y.sub.4 Y.sub.3 Y.sub.2 Y.sub.1 Add. Y.sub.4 Y.sub.3 Y.sub.2 Y.sub.1______________________________________ 0 1 0 1 0 30 1 1 0 0 1 1 0 1 0 31 1 1 0 0 2 1 1 1 1 32 1 1 0 1 3 1 1 1 1 33 1 1 0 1 4 1 0 1 0 34 1 1 0 0 5 1 0 1 0 35 1 1 0 0 6 1 1 1 1 36 1 1 0 1 7 NOP 1 1 1 1 37 OUT 1 1 0 1 8 JMP 1 0 1 0 38 1 1 0 0 9 1 0 1 0 39 1 1 0 0 A 1 1 1 1 3A 1 1 0 1 B 1 1 1 1 3B 1 1 0 1 C 1 0 1 0 3C 1 1 0 0 D 1 0 1 0 3D 1 1 0 0 E 1 1 1 1 3E 1 1 0 1 F 1 1 1 1 3F 1 1 0 110 1 1 1 0 40 1 0 1 011 1 1 1 1 41 1 0 1 012 1 1 1 0 42 1 1 1 113 1 1 1 1 43 1 1 1 114 1 1 1 0 44 1 0 1 015 1 1 1 1 45 1 0 1 016 1 1 1 0 46 INV 1 1 1 117 LOAD 1 1 1 1 47 & 1 1 1 118 (ST) 1 1 1 0 48 MCR 1 0 1 019 1 1 1 1 49 1 0 1 01A 1 1 1 0 4A 1 1 1 11B 1 1 1 1 4B 1 1 1 11C 1 1 1 04C 1 0 1 01D 1 1 1 1 4D 1 0 1 01E 1 1 1 0 4E 1 1 1 11F 1 1 1 1 4F 1 1 1 120 1 1 1 0 50 1 1 1 121 1 1 1 0 51 1 1 1 022 1 1 1 1 52 1 1 1 123 1 1 1 1 53 1 1 1 024 1 1 1 0 54 1 1 1 125 1 1 1 0 55 1 1 1 026 0 1 1 1 56 1 1 1 127 0 1 1 1 57 1 1 1 028 CTR 1 1 1 0 58 LOAD 1 1 1 129 1 1 1 0 59 (ST) 1 1 1 02A 1 1 1 1 5A 1 1 1 12B 1 1 1 1 5B 1 1 1 02C 1 1 1 0 5C 1 1 1 12D 1 1 1 0 5D 1 1 1 02E 0 1 1 1 5E 1 1 1 12F 0 1 1 1 5F 1 1 1 060 1 1 1 0 90 1 1 1 061 1 1 1 0 91 1 1 1 062 1 1 1 1 92 1 1 1 063 1 1 1 1 93 1 1 1 064 1 1 1 0 94 1 1 1 065 1 1 1 0 95 1 1 1 066 1 1 1 1 96 1 1 1 167 1 1 1 1 97 1 1 1 168 TMR 1 1 1 0 98 AT 1 1 1 069 1 1 1 1 99 1 1 1 06A 1 1 1 1 9A 1 1 1 06B 1 1 1 1 9B 1 1 1 06C 1 1 1 0 9C 1 1 1 06D 1 1 1 0 9D 1 1 1 06E 0 1 1 1 9E 1 1 1 16F 0 1 1 1 9F 1 1 1 170 1 1 0 1 A0 1 1 1 071 1 1 0 1 A1 1 1 1 172 1 1 0 0 A2 1 1 1 173 1 1 0 0 A3 1 1 1 174 1 1 0 1 A4 1 1 1 075 1 1 0 1 A5 1 1 1 176 1 1 0 0 A6 1 1 1 177 1 1 0 0 A7 1 1 1 178 OUTC 1 1 0 1 A8 OB 1 1 1 079 1 1 0 1 A9 1 1 1 17A 1 1 0 0 AA 1 1 1 17B 1 1 0 0 AB 1 1 1 17C 1 1 0 1 AC 1 1 1 07D 1 1 0 1 AD 1 1 1 17E 1 1 0 0 AE 1 1 1 17F 1 1 0 0 AF 1 1 1 180 1 1 1 0 B0 1 1 1 081 1 1 1 0 B1 1 1 1 082 1 1 1 0 B2 1 1 1 183 1 1 1 1 B3 1 1 1 184 1 1 1 0 B4 1 1 1 185 1 1 1 0 B5 1 1 1 186 1 1 1 0 B6 1 1 1 187 1 1 1 1 B7 OT 1 1 1 188 AB 1 1 1 0 B8 1 1 1 089 1 1 1 0 B9 1 1 1 08A 1 1 1 0 BA 1 1 1 18B 1 1 1 1 BB 1 1 1 18C 1 1 1 0 BC 1 1 1 18D 1 1 1 0 BD 1 1 1 18E 1 1 1 0 BE 1 1 1 18F 1 1 1 1 BF 1 1 1 1C0 1 1 1 0 E0 1 1 1 1C1 1 1 1 0 E1 1 1 1 0C2 1 1 1 1 E2 1 1 1 1C3 1 1 1 0 E3 1 1 1 1C4 1 1 1 0 E4 1 1 1 1C5 1 1 1 0 E5 1 1 1 0C6 1 1 1 1 E6 1 1 1 1C7 1 1 1 0 E7 1 1 1 1C8 ABC 1 1 1 0 E8 OBC 1 1 1 1C9 1 1 1 0 E9 1 1 1 0CA 1 1 1 1 EA 1 1 1 1CB 1 1 1 0 EB 1 1 1 1CC 1 1 1 0 EC 1 1 1 1CD 1 1 1 0 ED 1 1 1 0CE 1 1 1 1 EE 1 1 1 1CF 1 1 1 0 EF 1 1 1 1D0 1 1 1 0 F0 1 1 1 1D1 1 1 1 0 F1 1 1 1 1D2 1 1 1 1 F2 1 1 1 1D3 1 1 1 1 F3 1 1 1 1D4 1 1 1 0 F4 1 1 1 0D5 1 1 1 0 F5 1 1 1 0D6 1 1 1 0 F6 1 1 1 1D7 1 1 1 0 F7 1 1 1 1D8 ATC 1 1 1 0 F8 OTC 1 1 1 1D9 1 1 1 0 F9 1 1 1 1DA 1 1 1 1 FA 1 1 1 1DB 1 1 1 1 FB 1 1 1 1DC 1 1 1 0 FC 1 1 1 0DD 1 1 1 0 FD 1 1 1 0DE 1 1 1 0 FE 1 1 1 1DF 1 1 1 0 FF 1 1 1 1______________________________________
Time control 62 also ia a ROM. It was of the type H PROM 1-1024-5B hereinafter more fully identified in Table VII. ROM 62 was programmed in accordance with Table II.
TABLE II______________________________________PROM 62Hex Outputs Hex OutputsAdd. Y.sub.4 Y.sub.3 Y.sub.2 Y.sub.1 Add. Y.sub.4 Y.sub.3 Y.sub.2 Y.sub.1______________________________________ 0 1 0 0 0 20 1 0 0 0 1 1 0 1 0 21 1 0 1 0 2 1 1 0 0 22 1 1 0 0 3 1 1 1 0 23 1 1 1 0 4 1 0 0 1 24 1 0 0 1 5 1 0 1 1 25 1 0 1 1 6 1 1 0 1 26 1 1 0 1 7 1 1 1 1 27 1 1 1 1 8 1 0 0 0 28 1 0 0 0 9 1 0 1 0 29 1 0 1 0 A 1 1 0 0 2A 1 1 0 0 B 1 1 1 0 2B 1 1 1 0 C 1 0 0 1 2C 1 0 0 1 D 1 0 1 1 2D 1 0 1 1 E 1 1 0 1 2E 1 1 0 1 F 1 1 1 1 2F 1 1 1 110 1 0 0 0 30 1 0 0 011 1 0 1 0 31 1 0 1 012 1 1 0 0 32 1 1 0 013 1 1 1 0 33 1 1 1 014 1 0 0 1 34 1 0 0 115 1 0 1 1 35 1 0 1 116 1 1 0 1 36 1 1 0 117 1 1 1 1 37 1 1 1 118 1 0 0 0 38 1 0 0 019 1 0 1 0 39 1 0 1 01A 1 1 0 0 3A 1 1 0 01B 1 1 1 0 3B 1 1 1 01C 1 0 0 1 3C 1 0 0 11D 1 0 1 1 3D 1 0 1 11E 1 1 0 1 3E 1 1 0 11F 1 1 1 1 3F 1 1 1 1State 040 0 0 0 0 60 0 0 0 041 0 0 0 0 61 0 0 0 042 0 1 0 0 62 0 1 0 043 0 1 0 0 63 0 1 0 044 0 0 0 1 64 0 0 0 145 0 0 1 1 65 1 0 1 146 0 1 0 1 66 0 1 0 147 0 1 1 1 67 0 1 1 148 1 0 0 0 68 0 0 0 049 1 0 0 0 69 0 0 0 04A 1 1 0 0 6A 0 1 0 04B 1 1 0 0 6B 0 1 0 04C 1 0 0 1 6C 1 0 0 14D 1 0 1 1 6D 1 0 1 14E 1 1 0 1 6E 0 1 0 14F 1 1 1 1 6F 1 1 1 150 0 0 0 0 70 0 0 0 051 0 0 0 0 71 0 0 0 052 0 1 1 0 72 0 1 1 053 0 1 1 0 73 0 1 1 054 0 0 0 1 74 0 0 0 155 0 0 1 1 75 0 0 1 156 0 1 0 1 76 0 1 0 157 0 1 1 1 77 0 1 1 158 1 0 0 0 78 0 0 0 059 1 0 0 0 79 0 0 0 05A 1 1 1 0 7A 0 1 1 05B 1 1 1 0 7B 0 1 1 05C 1 0 0 1 7C 1 0 0 15D 1 0 1 1 7D 0 0 1 15E 1 1 0 1 7E 1 1 0 15F 1 1 1 1 7F 0 1 1 1STATE 180 1 0 1 0 A0 1 0 1 081 1 1 1 0 A1 1 0 1 082 1 0 1 0 A2 1 1 1 083 1 1 1 0 A3 1 1 1 084 1 0 1 0 A4 1 1 1 085 1 1 1 0 A5 1 1 1 086 1 0 1 0 A6 0 0 1 087 1 1 1 0 A7 0 0 1 088 1 0 1 1 A8 1 0 1 189 1 1 1 1 A9 1 0 1 18A 1 0 1 1 AA 1 1 1 18B 1 1 1 1 AB 1 1 1 18C 1 0 1 1 AC 1 0 1 18D 1 1 1 1 AD 1 0 1 18E 1 0 1 1 AE 1 1 1 18F 1 1 1 1 AF 1 1 1 190 1 0 1 0 B0 1 0 1 091 1 0 1 0 B1 1 0 1 092 1 0 1 0 B2 1 1 1 093 1 0 1 0 B3 1 1 1 094 1 0 1 0 B4 0 1 1 095 1 0 1 0 B5 0 1 1 096 1 0 1 0 B6 1 0 1 097 1 0 1 0 B7 1 0 1 098 1 0 1 1 B8 1 0 1 199 1 0 1 1 B9 1 0 1 19A 1 0 1 1 BA 1 1 1 19B 1 0 1 1 BB 1 1 1 19C 1 0 1 1 BC 1 0 1 19D 1 0 1 1 BD 1 0 1 19E 1 0 1 1 BE 1 1 1 19F 1 0 1 1 BF 1 1 1 1STATE 2C0 1 0 0 1 E0 1 0 0 1C1 1 0 1 1 E1 1 0 1 1C2 1 1 0 1 E2 1 1 0 1C3 1 1 1 1 E3 1 1 1 1C4 1 0 0 1 E4 1 0 0 1C5 1 0 1 1 E5 1 0 1 1C6 1 1 0 1 E6 1 1 0 1C7 1 1 1 1 E7 1 1 1 1C8 1 0 0 1 E8 1 0 0 1C9 1 0 1 1 E9 1 0 1 1CA 1 1 0 1 EA 1 1 0 1CB 1 1 1 1 EB 1 1 1 1CC 1 0 0 1 EC 1 0 0 1CD 1 0 1 1 ED 1 0 1 1CE 1 1 0 1 EE 1 1 0 1CF 1 1 1 1 EF 1 1 1 1D0 1 0 0 1 F0 1 0 0 1D1 1 0 1 1 F1 1 0 1 1D2 1 1 0 1 F2 1 1 0 1D3 1 1 1 1 F3 1 1 1 1D4 1 0 0 1 F4 1 0 0 1D5 1 0 1 1 F5 1 0 1 1D6 1 1 0 1 F6 1 1 0 1D7 1 1 1 1 F7 1 1 1 1D8 1 0 0 1 F8 1 0 0 1D9 1 0 1 1 F9 1 0 1 1DA 1 1 0 1 FA 1 1 0 1DB 1 1 1 1 FB 1 1 1 1DC 1 0 0 1 FC 1 0 0 1DD 1 0 1 1 FD 1 0 1 1DE 1 1 0 1 FE 1 1 0 1DF 1 1 1 1 FF 1 1 1 1STATE 3______________________________________
In the foregoing description FIGS. 3-6 relate to the contents of the controller 10, FIG. 1. Controller 10 may be made to respond to input devices, such as switches 407 and 412, FIG. 1, to control output devices, such as motors 405 and 406. The unique requirements that are to be satisfied through the use of controller 10 are specified by conventional means such as the ladder diagram of FIG. 2. Suitable preset states are entered into memory in controller 10 from the unit 600 when connected as illustrated in FIG. 1.
PROGRAMMER -- FIGS. 1, 1A, 1B 7-10
Unit 600 FIG. 1 is a small portable keyboard input unit. Four sets of keys are included. The first set, 600c, is an 11 key set having the numerals 0-9 and a CLR (clear) button. The second set, 600d, is a four key set identified as INS (insert), WRT (write), INC (increment), and READ.
The third set, 600e, is a four key set, three of which are used, namely IN-X, OUT-Y and CR (control relay).
The fourth set, 600f, is an eight key set including ST (start of store term), CTR (counter), TMR (timer), MCR (master control relay), OUT (output), INV (invert or not), OR, and AND.
Associated with the keyboard is an array 600g of neon seven segment numerical displays, such as conventionally provided in hand calculators.
Light emitting diodes 600h are provided with one such indicator for each of the keys in the set 600f. Light emitting diodes 600j are provided, one for each of the keys X, Y, and CR and one for the none key location AI.
Programmer 600, as shown in FIG. 1, serves to provide for operation in any selected one of five different modes. A mode is selected by depressing any one of the four buttons in set 600d or the clear (CLR) button of set 600c. Depression of the clear button in set 600c serves to clear registers and storage units hereinafter identified preparatory to performing any one of the functions in set 600d.
In the read mode, any instruction in the memory of FIG. 5 may be read. This may be done by first entering through the keyboard 600c the address in memory of the instruction which is to be read, i.e., from 0 through 255. Depression of the read key thereafter causes the instruction to appear in the display 600g and further causes the appropriate LED elements in sets 600h and 600j to be illuminated.
In the increment mode, any address that has been entered into the unit 600 by way of its keyboard and has not been cleared will be incremented by a factor of one upon depression of the INC button and clears the left portion of the display and the OP code command. For example, if the button CLR in set 600c is depressed, followed by depressing the INC button of set 600d, the address then effective in the machine will be address No. 1, but if the address presented by display 600g is 250, it will be incremented to 251.
Memory addresses effective at a given time are displayed on the right hand four digits of display 600g.
In the write mode, any new instruction desired can be written into memory. If an instruction previously was placed in memory at the desired location, the write mode causes the new instruction to be written over the previous instruction.
In the insert function, a new instruction can be inserted at any point in memory with every subsequent instruction stored in memory being shifted one memory location higher upon depression of the INS button. For example, in terms of the ladder diagram of FIG. 2, if the ladder rung including motor 405 occupied memory locations 100, 101 and 102 and it is desired to insert into memory beginning at location 100 the rung including motor 406, then the following operations would be carried out, using programmer 600.
Step 1: depress clear button.
Step 2: enter the address, i.e., depress buttons 100.
Step 3: depress ST (start-store) and X (in) buttons.
Step 4: since switch 407 occupies the I/O address No. 9, depress numeral 9 of set 600c.
Step 5: depress INS button (insert) of set 600d.
This establishes in memory location 100 the switch 407.
Step 6: depress button INC.
Step 7: depress button AND of set 600f.
Step 8: depress key X of set 600e.
Step 9: since switch 412 occupies I/O address 16, depress keys 1 and 6 of set 600c.
Step 10: depress key INS of set 600d.
This completes insertion of element 412 into memory location 101 together with its relation to switch 407.
Step 11: depress button INC of set 600d.
Step 12: depress button OUT of set 600f.
Step 13: depress button Y of set 600e.
Step 14: since motor 406 occupies I/O address 8, depress numeral 8 of set 600c.
Step 15: depress button INS of set 600d.
This completes entry of the motor 406 into memory location 102 together with its relation to switches 407 and 412.
The elements of the second rung previously occupied memory addresses 100, 101 and 102. Entry of switch 407 into memory shifts all elements in memory up one memory address. The same is true upon insertion of the switch 412 and upon insertion of the motor 406. Thus, the elements of the rung involving motor 405 occupy new memory locations 103, 104 and 105. The push buttons illustrated in FIG. 1 actuate switches connected in the circuit arrangement illustrated in FIGS. 1A and 1B. In FIG. 1A, eight lines, M0-M7, lead to the keyboard. Four lines KBD2, KBD3, KBD6 and KBD7 lead from the keyboard. The push button switches are connected in the resulting matrix to provide coded outputs on the four lines leading from the keyboard. All of the switches in set 600c (except switch CLR), set 600e and set 600f are involved in the x-y matrix of FIG. 1A as indicated by the legends therein. Depression of the zero switch on keyboard 600c, FIG. 1, established continuity between line M0 and line KBD2 of FIG. 1A. It will be noted that the switches MCR and INV provide the same function, i.e., the closure of each causes continuity to be established between input line M4 and output line KBD7.
In FIG. 7, unit 600 has lines M0-M7 which lead to the keyboard in the manner illustrated in FIG. 1A. The lines KBD2 and KBD3, FIG. 6, and linens KBD6 and KBD7, FIG. 9, lead from the keyboard.
The circuit of FIGS. 7-10 includes two primary data loops responsive to commands entered by way of the keyboard. The two data loops will first be generally described before discussing further the utilization of the keyboard arrangement of FIGS. 1, 1A and 1B.
The first data loop leads from the sequencer 10, FIGS. 3 and 4, through a Schmitt trigger 601, FIG. 9, and includes shift registers 602-606, FIGS. 9 and 10. Operating with the shift registers 604-606 are binary up/down counters 607-609, respectively.
The output of the first data loop passes by way of inverter 610 to line 174 which leads back to sequencer 10. Any signals or data type information that is to be transmitted from unit 600 to sequencer 10 must pass through the shaft registers 604-606 and thence to line 174.
The second loop is a binary coded decimal (BCD) loop. It is a numeric data loop accommodating 32 bits. A first 16 bits are stored in shift registers 612 and 613, FIG. 7. The second 16 bits are stored in shift registers 614-617, FIG. 10. The loop through which the data flows includes the input line 618 connected to the A and B (NAND) input terminals of shift register 612. The data bits are clocked sequentially through register 612-617 and thence by way of the output line 619, NAND gate 620 and NAND gate 621 back to line 618.
Numeric data entered from the keyboard in unit 600 is placed into the loop 612-621 by way of a shift register 622. Four lines 623 lead to shift register 622. The states on line 623 are controlled by counters 624 and 625 as driven by a low speed clock (LSC) oscillator 626. Clock 626 is free running relative to clock 50 of sequencer 10. A second oscillator is provided along with oscillator 626. The second is a high speed clock (HSC) oscillator 626a. They operate at frequencies of about 180 kilohertz and 1.8 megahertz, respectively.
Oscillator (LSC) output line 627 leads to the clock input terminal of counter 624. The QD output terminal of counter 624 is connected by way of line 628 to the clock input terminal of counter 625. Counters 624 and 625 operate in conjunction with decoders 630 and 631 such that the outputs of decoders 630 scan the switches in the keyboard. Output states on lines 633 leading from decoder 631 strobe display 600g and strobe the outputs of the keyboard, i.e., output lines W2, W3, W6 and W7. Lines labeled M0-M7 of FIG. 1A correspond with lines 632 of FIG. 7.
Line KBD2 from the keyboard leads to a NOR gate 634, the second input of which is the line W2 from the set 633. Similarly, keyboard line KBD3 leads to a NOR gate 635, the second input of which is line W3. Line KBD6 leads to a NOR gate 636, the second input of which is line W6. The line KBD7 leads to NOR gate 637, the second input of which is line W7. Gates 634 and 635 supply the inputs to a NOR gate 638. Gates 636 and 637 supply the inputs to a NOR gate 639. The output of gate 638 is connected through a single pulse circuit 640 to produce on output line 641 a digit clock pulse which is applied to the clock input terminal of register 622 to load into register 622 the code on lines 623 representing the numeric key on the keyboard that had been depressed. Pulses from clock oscillator 626 as provided by counter 624 through decoder 630 provide a keyboard strobing sequence. Line MO goes low initially, followed by lines M1 . . . M7 following which the line MO goes low again and the cycle is repeated. Gating into register 622 of the code on lines 623 is controlled by depressing a key on the keyboard. The particular code on lines 623 is the one that happens to be present at the instant of time that a particular pulse occurs in response to pressing a given key. The keyboard operation thus far described is essentially the same as in calculators manufactured and sold by Texas Instruments Incorporated of Dallas, Texas and identified as TI2500 Pocket Calculator.
Thus, actuation of any of keys 0-9 in set 600c will cause to be loaded into register 622 a binary code representative of the selected numeral 0-9.
The selected numeral in register 622 may then be inserted into the BCD loop and ultimately transferred into registers 604-606. The data placed in registers 604-606, except in a few cases which will hereinafter be discussed, is the I/O address of a given connector element located along cable 399. It will be recalled that there are, in the embodiment described, 256 input addresses and 256 output addresses along cable 399. In unit 400 the first eight units 400a are input units, the second eight units 400b are output units. As above described, the I/O address designates the location of such a connector unit as is employed to connect to motor 406, to switch 407, to switch 412, etc.
The programming unit 600 also serves to encode selected OP codes which are entered by actuating switches in the set 600f. Unit 600 also permits identifying desired I/O address modifiers by actuating one of the keys in set 600e.
The circuit operates to store the OP codes in register 602 and to store the I/O address modifiers in register 603. The circuitry associated with registers 602 and 603 permits manual insertion of a desired OP code or multiple OP codes and removal of one or all of the OP codes that have been inserted in order to give an operator flexibility in entering a given set of data representing a ladder network or modifying a set of data that has previously been loaded in the system. More particularly, actuation of a key to energize either lines KBD6 or KBD7 will cause data on lines 650 to be decoded for loading into registers 602 and 603. The logic circuits within the dotted outline 651 serve to decode data from lines 650 into binary form for storage in registers 602 and 603. The code stored in such registers is representative of the OP codes designated in FIGS. 1, 1A and 1B and associated with lines KBD6 and KBD7.
The states appearing at the outputs of the gates in unit 651 are set out in Table III.
TABLE III______________________________________Key 651b 651c 651d 651e 651f 651g______________________________________X 0 0 0 0 0 1Y 0 0 0 0 1 0CR 0 0 0 0 1 1AND 1 0 0 0 0 0OR 1 0 1 0 0 0ST 0 0 0 1 0 0CTR 0 0 1 0 0 0OUT 0 0 1 1 0 0MCR 0 1 0 0 0 0INV 0 1 0 0 0 0TMR 0 1 1 0 0 0______________________________________
Output states of Table III are generated as follows. Line W7 from set 633 is connected to one input of NAND gate 651a and to one terminal of AND gate 651b. The line W6 from set 633 is connected to one input of AND gate 651c and to one input of AND gate 651e. The three least significant bit lines of line 623 are then connected to the circuit 651. More particularly, the QA output of counter 625 is connected through an inverter 651h to the second input of NAND gate 651a and to the second input of AND gate 651c. The QD output of counter 624 is connected to the second input of AND gate 651d and to one input of AND gate 651f. The output of NAND gate 651a is connected to a second input of AND gate 651d and by way of inverter 651j to inputs to each of AND gates 651f and 651g.
The QC output of counter 624 is connected to the second input of AND gate 651e and to the second input of AND gate 651g.
The outputs of AND gates 651b-651g are connected to one input of exclusive OR gates 651m-651s, respectively. The QA-QD outputs of shift register 602 supply the second inputs of exclusive OR gates 651m-651q, respectively. The QA and QB outputs of shift register 603 supply the second inputs of exclusive OR gates 651r and 651s, respectively.
The data stored in shift register 602 is the OP code. There are sixteen OP codes employed in the present example. Such OP codes are set out in Table IV.
TABLE IV______________________________________ OUTPUTOP CODE 651m 651n 651p 651q______________________________________JUMP 0 0 0 0ST (LOAD) 0 0 0 1CTR 0 0 1 0OUT 0 0 1 1MCR/INVERT 0 1 0 0ST INVERT (LOAD) 0 1 0 1TMR 0 1 1 0OUT INVERT 0 1 1 1AND 1 0 0 0AND ST 1 0 0 1OR 1 0 1 0OR ST 1 0 1 1AND INVERT 1 1 0 0AND ST INVERT 1 1 0 1OR INVERT 1 1 1 0OR ST INVERT 1 1 1 1______________________________________
The data stored in shift register 603 is the I/O address modifier. There are three modifiers employed herein, as set out in Table V.
TABLE V______________________________________Key 651r 651sX 0 1Y 1 0CR 1 1______________________________________
All of the Op codes set out in Table IV are selectable by actuation of keys in set 600f, FIG. 1. Some of the OP codes, it will be noted, involve entries made by depressing two of the keys in set 600f and some by depressing three of the keys.
From an inspection of the circuit involving the exclusive OR gates 651m-651q, it will be seen that any OP code which appears at the output of unit 651 will be entered into register 602 if register 602 is clear. However, if the same OP code button is depressed a second time, then the feedback by way of channel 602a will cause the OP codes previously entered into register 602 to be erased. The circuit thus provides for a selected bit-by-bit entry into register 602 and bit-by-bit erasure thereof without otherwise modifying the operation of the programming unit 600 in any way. For example, referring to FIG. 1, assume an operator attempted to insert switch 412 and erroneously depressed the OR button in step 7 of the sequence above described in the previously given example rather than the AND button. If the operator then recognized the error and desired to correct the same, the correction could merely be made by depressing the OR button again followed by depression of the AND button. The sequence of operations would change the code in register 602 from 1010 to 1000. Thus the selective insertion and removal of a single bit to change the code. Use of the exclusive OR gates 651m-651q provides this unique sequence of operation, i.e., alternately entering and erasing a given code from register 602 upon repeated insertions of the same input command.
The same is true of the three lines leading to gates 651f and 651g of unit 651. They operate through exclusive OR gates 651r and 651s to control the LED displays 600j. At the same time, lines 603a are fed back to exclusive OR gates 651r and 651s for the selected control of the data in register 603.
The outputs of the shift register 602, in addition to being connected back to the exclusive OR gates 651m-651q, are also employed for controlling a light emitting diode display 600h. From the circuit shown, it will be seen that when a given button in the set 600f is depressed, the corresponding light emitting diode in display 600h will be illuminated. The diodess in set 600h, FIG. 9, bear the same legends as do the associated keys in the set 600f, FIG. 1. In a similar manner, the light emitting diodes labeled X, Y and CR of display 600j, shown in FIG. 10, are controlled by the QA and QB outputs of shift register 603.
The logic circuit 652 operates the same as the circuit 640 for controlled loading of registers 602 and 603.
It will be noted that a DIGIT CLOCK line is one of the outputs from circuit 640. This signals the fact that a digit code has been stored in register 622 and is to be inserted into the data loop that is being clocked through registers 612-617. This action is initiated by application of the DIGIT CLOCK signal to the load terminal of a state counter 653 and, through AND gate 654, to the clock input terminal of counter 653. Counter 653 is prewired so that it is forced to the count of five. The output lines QA-QD of counter 653 are connected to terminals A, B, C and STRB of a data selector unit 655 and to input lines of a decoder 656. Since the output from counter 653 is preset to five, the data selector 655 selects the signal on line 657 leading from a NOR gate 658 by way of an inverter 659.
A 32 bit word circulates in the second loop including shift registers 612-617. It continuously is shifted by SCAN clock pulses. Scan clock pulses are applied to the clock inputs of shift registers 612 and 613, and by way of NOR gate 660 to the clock input terminals of shift registers 614-617.
When a four bit word is stored in shift register 622, the object is to insert that word into the appropriate location in the 32 bit word already circulating in shift registers 612-617. The operation of the bit counter 653 and the data selector 655 in connection with decoder 656 causes a delay until the appropriate time for insertion arrives. This is caused by a delay interval during state 5 of data selector 655. Upon the occurrence of state 6 of data selector 656, the NAND gate 661 is enabled so that the output line QD from register 622, leading to NAND gate 662, will cause the word stored in register 622 to be inserted into the input of storage register 612. Data on line 619 then passes through register 622 trailing the word inserted into the loop from register 622. Thus, register 622 is included within the second data loop for 16 bits. During the state 6 from decoder 656, a NOR gate 663 is enabled. This causes signal MOW4 to be present. This generates through NOR gate 664 a load state on line 665 which leads to the load input terminals of binary coded decimal up/down counters 666-669. Counters 666-669 are connected to the shift registers 617-614, respectively. Line 665 also extends to the CLEAR terminals of binary counters 607-609 by way of inverter 655a.
Thus, the 16 bit data word is loaded in shift registers 666-669 and is to be converted to a binary counterpart which will be generated in counters 609-607. On state 7 of decoder 656 a high speed clock HSC applied by NAND gate 670 in conjunction with state 7 from decoder 656 enables AND gate 671 which is operated in an OR function so that HSC pulses then appear on clock line 672. Line 672 is then connected to the down input terminal of counter 666 and to the up input terminal of counter 609. Counters 666-669 then counter down to zero. During the same interval, counters 609-607 count up. At the instant that the counter 669 reaches zero count, a borrow signal appears on line 673 and is applied to NOR gate 674 which effectively is ANDed with state 7, thereby to apply by way of line 675 a load pulse to each of the load terminals of registers 604-606. At the instant of the borrow pulse, the contents of counters 607-609 are immediately captured in storage registers 604-606 and are thus available for reading out over line 611 to the sequencer.
In operation, the sequencer shown in FIGS. 3-6 once set in operation will repeat the wait-serial I/O-run modes following each peak in the a.c. power.
When programmer 600 is connected to the system and is to be used, the operation of the sequencer normally will continue uninterrupted. However, when the programmer of FIGS. 7-10 is placed in the read mode, the memory address specified by the operator is placed in counters 666-669. The counters then count down to zero. Upon reaching zero, the channels from NAND gate 601 and specifically, the enable terminals on registers 602, 603, 604, 605 and 606 are energized so that the words stored in memory at the location at the address initially specified in counters 666-669 will be brought out and stored in shift registers 602-606. Immediately, the LED displays 600h and 600j will be energized to display the contents of registers 602 and 603. The contents of registers 604-606 comprise the I/O address stored in the main memory location specified by the user. The I/O address thus contained in registers 604-606 is then loaded into counters 607-609. Counters 607-609 then count down to zero as counters 666-669 count up. When counters 607-609 reach zero, counters 666-669 stop counting. The output of the counters is then applied to the shift registers 614-617. The outputs thereof are then displayed. More particularly, the I/O address comprises 16 bits of the 32 bits circulating in the BCD loop. Each set of four of the 16 bits is latched by latch 690 whose output is applied to a decoder 691. The decoder 691 then is connected selectively to energize the segment drivers. One such segement driver is represented by the circuit 692. The 16 bits are thus employed to light up the left hand four digits on display 600g. The right hand four digits are decoded to display on the right hand four digits the memory address.
In the insert mode, an operator enters the desired data as above indicated. The OP code is stored in register 602. The modifier data is stored in shift register 603. The I/O address is entered into the BCD loop. The data is then transferred to the shift registers 604-606. In the run mode when the selected address is reached, the data from memory begins to flow to register 602 as data from register 606 begins to flow to memory. The data in memory is then passed as a serial stream through registers 602-606 until all the memory addresses have been read and rewritten in memory displaced by one memory address.
Entry of the numeric data, the entry of the Op codes and the entry of the I/O address modifiers has been described. Now to be described are the operations involving the entry of the five programmer mode commands, CLEAR, READ, WRITE, INSERT AND INCREMENT. The CLEAR push button of FIG. 1, when depressed, connects the CLEAR PB line of FIG. 9 to ground. This line is connected to an AND gate 900, the output of which is CLEAR signal. The output is also connected to an AND gate 901 and to the CLEAR terminals of registers 612 and 613. The output of gate 901 is connected to the CLEAR terminals of registers 602-606 and to the CLEAR terminals of registers 614-617.
When the READ button is depressed, line 902 is connected to ground. Line 902 leads to a NAND gate 903, the output of which is connected to a multivibrator 904 which is employed to prevent multiple entries of a single intended entry. More particularly, depression of a push button may close its switch several times. The circuit involving flip-flop 904 is a debouncing circuit having the output as a NOR gate 905. A line 906 serves to delay the signal thereby causing it to pass through gate 905 not before the multivibrator 904 has completed its cycle. The output of gate 905 is then supplied to one input of a NAND gate 907, the output of which is connected to the input terminal 0 of multiplexer 655. Second input of gate 907 is supplied by AND gate 908 which has as its inputs the M1W0 line from FIG. 7 and the OEN signal.
The INSERT push button and the WRITE push button also are connected to gate 903 and thus lead by way of gate 907 to the input 0 of multiplexer 655. The WRITE push button in addition to being connected to gate 903 is connected to a gate 909 and to the CLEAR Input terminal of a D-type flip-flop 910 by way of line 911. The WRITE push button is connected to gate 903 and to gate 909.
Three lines, RUN, PPGC and CPU3, are connected to the programming panel 600 from the sequencer of FIGS. 3-6. The RUN line is connected by way of inverter 913 to the clock input terminal of the D flip-flop 910 and to a gate 914. The Q output of flip-flop 910 is connected by way of inverter 915 to the clock input terminal of a B flip-flop 916. The output of gate 909 is connected to a CLEAR terminal of flip-flop 916 and to one input of a NAND gate 917. The output of NAND gate 917 is connected to an external load line 918 that leads to the sequencer. It is also connected through NAND gates 919 and 920.
The PPGC line from sequencer 10 is connected by way of inverter 921 to one input of gate 920.
The CPU3 line, as previously described, is connected by way of line 232 through input 3 of multiplexer 655. It is also connected to NAND gate 922 and NOR gate 923. The Q output of the flip-flop 916 is connected as a second input to NAND gate 917. The Q output of the flip-flop 910 is connected as the third input to NAND gate 917.
The output of NAND gate 917 is a key signal in communication between the sequencer 10 and the programmer 600. More particularly, the state on line 918 controls whether or not the sequencer 10 will receive data from the programmer 600 which may appear on line 174. In the READ mode, line 918 stays high at all times.
In the WRITE mode, the state on line 918 is low only for that interval of time during which a single word of 16 bits is read from registers 602-606 over line 174 to sequencer 10.
In the INSERT mode, line 918 is high until counters 666-669 reach a count following a START signal corresponding to the address in memory at which it is desired to insert a new instruction. At that instant, the line 918 goes low and the data from registers 602-607 flows over line 174 to sequencer 10 until the end of the cycle is reached, i.e., until all of the remaining of the instructions from memory have been read through registers 602-606 and back into memory.
When the WRITE button is depressed, the CLEAR line to the flip-flop 910 is low and the CLEAR line to flip-flop 916 is high. Each time that the sequencer begins the RUN mode, the clock terminal of flip-flop 910 is actuated so that the Q output is clocked to the same as the D input, or is made to go low. Thus, when the WRITE button is depressed, the output of flip-flop 910 remains low until the 2Y3 output of the multiplexer 656 goes low. This resets the flip-flop 910, that is, it causes the Q output to go high. When the preset pulse is removed, the Q output again goes low. At this instant, the flip-flop 916 is clocked through inverter 915 so that the Q output is in a zero state. The output of gate 917 will go low only if all of the inputs are high. Thus, on the WRITE mode, the output of gate 917 is low only during the interval of time that the preset input to the flip-flop 910, i.e., the 2Y3 output of the multiplexers 656, is low.
The circuit involving flip-flops 910 and 916, NAND gate 909 and the demultiplexer 656 operates in the INSERT mode to keep line 918 low for the interval following which the output of 2Y3 of the demultiplexer 656 goes low and until the end of the RUN cycle. The line 918 is connected through a NOR gate 930 and a NOR gate 931 to the CLEAR terminal of counter 653. The second input of gate 930 is the 2Y3 output of multiplexer 656. The second input of NOR gate 931 is supplied by a NAND gate 932. One input of gate 932 is the 1Y3 output of demultiplexer 656. The other input is the 1YO output of demultiplexer 656. The circuit involving NAND gate 931 will reset counter 653 at the end of the 2Y3 state when in the INSERT mode and at the end of the 1Y0 state when in The READ or WRITE mode. It will reset counter 653 in response to the 1Y3 state at the end of the numeric entry mode.
When the INC button is depressed, the input to a Schmitt trigger 940 is connected to ground. This initiates the operation of incrementing any address that is then circulating in the BCD loop 612-617. The output of Schmitt trigger 940 is connected to a NAND gate 941 and to a second NAND gate 942 as well as to the CLEAR terminals of D flip-flops 943 and 944. The output of gate 941 is connected to the clock input terminal of flip-flop 943. The Q output of flip-flop 943 is connected by way of gate 945 to the clock input terminal of flip-flop 944. The output of gate 941 is connected by way of inverter 946 and NAND gate 947 to the input of an AND gate 948. The Q output of flip-flop 943 is connected to one input of OR gate 949 and to a second input of NAND gate 947. The Q output of gate 944 is connected to the second input of NOR gate 949. The Q output is connected to the second input of NAND gate 942. The output of NOR gate 949 is connected to one input of a NOR gate 940, the second input of which is supplied by way of NAND gate 951 which is driven from the 2Yo output of multiplexer 656 by way of inverter 952. The second input to gates 945 and 951 is the timing signal MOWO output line from FIG. 7.
In operation it will be remembered that a given address is circulating in the BCD loop 612-617. When it is desired to increment that address by a factor of one, then the INC button is depressed. This removes the CLEAR signal from flip-flops 943 and 944. Through gate 942 the OEN (zero enable) signal is disabled and thus is no longer effective on gate 908. Gate 941 also is enabled. Gate 941 is supplied by way of gate 955 which is supplied by the state 2Y0 multiplexer 656 and, by way of inverter 956 with the MOW4 state from FIG. 7.
If the operation involving multiplexer 655, counter 653 and the multiplexer 656 is in the Zero state and MOW4 state is created, then the output of gate 941 goes low and then high in response to and conforming with MZOW4. This clocks the flip-flop 943 causing the Q output to go high and the Q to go low. This enables gate 945 and disables gate 947. The output of gate 945 then clocks flip-flop 944 when the state MOWO from FIG. 7 is generated. On the first pulse out from gate 941, an output of gate 947 is pulsed low and is applied by way of AND gate 948 to the up count terminal of the counter 666 to increment at that instant the address that was then stored in the registers 666-669. At the same time, the signal is applied by way of AND gate 901 to clear the registers 614-617.
Before the INC button was depressed, the output of gate 942 was enabled so that through 908 the counter system could proceed through its cycle. Then the INC button is depressed, the output of gate 942 is disabled so that the counter system cannot proceed until after the increment operation has been completed. When the MOWO signal is applied to the flip-flop 944, the output of gate 942 is again enabled so that the counter 653 can then proceed with its operation.
TIMING -- FIGS. 11A-C
In FIG. 11A, certain timing functions employed in the system above described are illustrated. The functions illustrated in FIG. 11A will be given the same numeric labels as appear in FIGS. 2-6.
It will be remembered that sequencer 10 as above described operates through three modes, (a) wait, (b) serial I/O and (c) run. In FIG. 11A, waveform 800 illustrates the sync pulse supplied to line 11e, FIG. 3. The sync pulse waveform 800 is characterized by a step 800a at the peak of the a.c. voltage cycle.
Coincident with step 800a is the initiation of the serial I/O mode of sequencer 10. The cycle enable waveform 801 is generated at the output of NAND gate 11a and appears on line 81, FIG. 3.
Waveform K2 is one of the outputs of counter 39 and is a pulse train of one megacycle pulse rate. Oscillator 50, FIG. 4, in the embodiment here described had a frequency of 8 megacycles. The output KO of counter 39 had the frequency of 4 megacycles. The output K1 had the frequency of 2 megacycles while the output KO and K1 labeled on the drawings are not used in the operation of the system but are merely employed in counter 39. Thus, the waveform 802 is the one megacycle main control pulse K2.
Waveform 803 is the KQD signal appearing at the last output of counter 39. It runs at one-half the frequency of K2 or one-half megacycle pulse rate during the serial I/O mode of the sequencer. Thereafter it pulses one pulse every 16 of the K2 pulses having output pulses 803a, 803b, etc. Thus, the waveform 803 has a half megacycle rate during the I/O mode, a half megacycle rate divided by sixteen during the first part of the run mode and then reverts to the half megacycle pulse rate during the write-to-main-memory portion of the run mode.
In FIG. 11A, the serial I/O state begins when the waveform 801 goes high. The serial I/O state ends at the end of interval 804.
The run mode starts at the end of interval 804 and extends to the end of interval 805.
Waveform 806 is the image register write pulse that is applied to the R/W terminal of image register 20, FIG. 4.
Waveform 807 is the gate output signal appearing at the output NAND gate 109, FIG. 4. Thus, the data registers 13-15 count continuously during the I/O mode. During the time that waveform 806 is effective, the states of 256 input units on cable 399 are read into the image register 20 in the order 0, 1, 2 . . . 254, 255. At the end of the serial input portion of the I/O mode, 512 flag states are read out of image register 20. They are read out at the higher clock rate of the K2 waveform 802. They are read out in the order 0, 1, 2, . . . 510, 511.
Thereafter, the state on line 108, FIG. 3, reverses so that the order in which the output data stored in image register 20 is read out will be reversed. Thus, during the last portion of the serial I/O cycle, the states to be imposed upon the 256 output units on cable 399 are read out in reverse order. That is, the state of the most remote output unit on cable 399 is read out first. They are read out at the high clock rate K2 of waveform 802 and in the order 255, 254 . . . 1, 0.
At this point, the end of the I/O state is reached and the system then operates in the run mode. The first portion of the run mode, namely the interval 810, is employed for the reading instructions from memory into data registers 12-15 at the main clock rate K2 of waveform 802. At the same time, a corresponding train PPGC at the K2 rate, represented by waveform 811, is generated and is the program panel gated clock pulse train. Thus, the program panel of FIG. 1 is the only element of the system that employs waveform 811.
During the interval 810, a memory word comprising 16 digits is read from the main memory into the data register.
During the interval 812, the instruction is executed by the sequencer 10. The waveform 813 is the AIQ (MCR + JMP) which appears at terminal Y3 of processor 61.
The waveform 814 is the signal OUT + OUT C which appears at the Y2 terminal of processor 61. In the interval 815, a second word is read out of memory and during the interval 816 the second word is executed. Thus, words 0 and 1 from memory are read and executed. Normally the sequencer would proceed to read and execute all instructions in memory.
In the example given in FIG. 11, a break in the memory sequence is shown. More particularly, after the execution of word 2, a step waveform 820 is generated which causes the data registers 12-15 to be loaded from the external memory, i.e., from memory in the programming unit 600. Waveform 820 appears on line 144 of FIG. 3. When present, the next word read into the data registers 12-15 is derived from the programming panel and is read in during the interval 821. At the end of the interval 821, the RITE FF waveform 822 is driven low. This terminates or inhibits the PPGC waveform 811 from being effective on the programming terminal 600 and causes the sequencer then to write the contents of the data registers 12-15 into memory at the word 3 location in memory, i.e., at the same location that was read out of memory during the interval 821. Thus, the memory write interval 823 is employed for each purpose. At the end of the interval 823, the waveform 822 then goes high, initiating flow of the PPGC pulses, waveform 811, to the programming panel 600 and continuing by reading word 4 from memory as in interval 824.
The foregoing operations then continue until the last of the instruction words in memory have been read and executed as desired has been accomplished. At this point in time, the scan complete signal, waveform 825, is generated. This signal appears at the output of the NAND gate 11, FIG. 3. The scan complete waveform 825 causes the cycle enable waveform 801 to go low and beginning at the end of interval 805, sequencer 10 waits for the next peak of the power voltage to repeat the same cycle again. The end cycle waveform 826 brings operations to a halt. In this state sequencer 10 remains until the next peak occurs.
It will be noted that the scan complete waveform 825 is applied to the clear input terminal of flip-flop 93 and the end cycle waveform 826 is applied to the preset terminal flip-flop 93 to produce waveform 822a, a negative going pulse. Pulse 822a assures that the last of the words from memory will be read and completely executed before the run mode interval 805 terminates. In each of intervals 821, 823 and 824, instruction words are read to or from memory, i.e., at the beginning of each such interval a set 830 of control pulses are generated. They comprise:
a KQD negative going pulse one microsecond long which, when it returns true, marks the beginning of a memory cycle as in interval 821;
a gated ck pulse, i.e., a positive pedestal of one and one-half microseconds in length extending one microsecond longer than the KQD pulse;
an AID pulse, either AID = 1 or AID = 0. The active indicator is flip-flop 86, FIG. 3. The AID signal is the signal applied to the D input of flip-flop 86.
If the Q output of the active indicator 86 is to be true as a result of the preceding memory cycle, then the signal applied to the D input terminal will have the form AID = 1 which is a negative going pulse which becomes true one-half microsecond before the end of KQD. If the Q output of active indicator 86 is to be false, then the signal applied to the D input of flip-flop 86 will have the form AIQ = 0, a pulse two microseconds long, going true one-half microsecond after dotted line 831. Dotted line 831 coincides in time with the trailing edge of a negative pulse AICK and PDS CK, i.e., the clock pulses applied to flip-flop 86 and the clock pulses applied to push down stack shift register 80.
The active indicator 86 shifts state on dotted line 831. Active indicator 86 holds results of execution of instruction and serves as a one bit wide accumulator. All store terms load new data into the active indicator. The push down stack shifts data down on two OP codes, shifts up on four OP codes and does nothing on ten OP codes.
More particularly, the push down stack has the responses indicated in Table VI to the sixteen OP codes involved.
TABLE VI______________________________________OP CODE PUSH DOWN STACK______________________________________ST (STORE TERM) (LOAD) Shift down 0001ST-INV (STORE TERM, INVERT) (LOAD) Shift down 0101AND-ST (AND STORE TERM) Shift up 1001AND-INV-ST (AND, INVERT, STORE TERM) Shift up 1101OR-ST (OR, STORE TERM) Shift up 1011OR-INV ST (OR, INVERT, STORE TERM) Shift up 1111AND (AND) No shift 1000ANDC (AND COMPLEMENT) No shift 1100OR (OR) No shift 1010ORC (OR COMPLEMENT) No shift 1110OUT (OUTPUT) No shift 0011OUTC (OUTPUT COMPLEMENT) No shift 0111MCR (MASTER CONTROL RELAY) or INVERT No shift 0100JMP (JUMP) or NO OP No shift 0000TMR (TIMER) No shift 0110CTR (COUNTER) No shift 0010______________________________________
Table VI includes the OP codes as they appear on lines B15-B12 leading from register 12, FIG. 3. More particularly, for the OP code, ST lines B15-B12 apply the four bit word 0001 to processor 61.
TIMING -- FIG. 11D
Referring to FIG. 11D, waveforms 800, 841 and 842 have been shown. The cycle enable waveform is the waveform appearing on line 81 at the output of NAND gate 11a. The peak of each a.c. half cycle occurs at the point 800a on waveform 800.
The K14 output of counter 38 involves a positive going pulse which occurs once for each half cycle of the a.c. power voltage. The K14 signal represented by waveform 841 is applied by way of inverter 96 to the clock input terminal of the timer counter 35. The timer enable signal illustrated by waveform 842 thus is caused to have an output pulse for every twelve pulses in the waveform 841. This means that the pulses on the timer enable waveform 842 occur at one-tenth second intervals. The output of the timer counter 35 is the CRY output. It is applied by way of liine 125 to the D input terminal of processor 61 and is employed for timing operation in utilization of the sequencer 10. Such a timer is indicated by the unit 417 of FIG. 1. The timing instructions are loaded in main memory and may thus be read from memory to become effective in controlling the operation of the sequencer. The control for such timing operations is involved in the programming set out in Tables I and II for processors 61 and 63, respectively.
TIMING -- FIG. 11E
FIG. 11E illustrates the relationship between (1) the KQD waveform 803, (2) the AIQ (MCR+JMP), waveform 813 which appears at the output of processor 61, (3) the counting output of the flip-flop 213, FIG. 6, as represented by waveform 843, and (4) the OUT+OUTC 814.
The KQD waveform 803 represents negative going pulses of one microsecond duration occurring every seventeen microseconds. The flip-flops 211, 212, 213 and 214 respond to the signals B0-B7 and to the AIQ (MCR+JMP) to produce the counting output waveform 843. Three OUT+OUTC pulses are generated within the positive pedestal of the counting output waveform 843. Waveform 843 might extend for 256 OUT+OUTC pulses. The length of the counting waveform 843 depends upon the values of the inputs B0-B7, FIG. 6, at the instant that the AIQ(MCR+JMP) pulse occurs.
I/O UNITS -- FIGS. 13 and 14
In FIG. 1 the controller 10 is shown connected by way of cable 399 to I/O units mounted on bases 400 and 401. Output unit 409 is shown mounted on base 400. Input unit 411 is shown mounted on base 401. The bases 400 and 401 are interconnected by way of a cable 399a. Base 401 is connected by way of cable 399b to additional bases so that, as above described, a total of 256 output units such as unit 409 may be employed along with a total of 256 inputs units such as input unit 411.
FIGS. 13 and 14 illustrate the manner in which power conveyed to the bases 400 and 401 as by way of power cables 397 and 398 is utilized. In the case of motor 406, the output unit 409 is utilized to control the application of power from cable 397 through lines 408 to motor 406. The interface to accomplish this is illustrated in FIGS. 13 and 14.
Cable 397 has one conductor which is connected to one terminal of a triac 701. The other terminal of triac 701 is connected by way of line 408a to one terminal of motor 406. The other terminal of motor 406 is connected by way of common line 408b to the second conductor in cable 397. The circuit responsive to controller 10 operates to turn on triac 701 upon a given output state from the controller 10.
Control for the triac 701 includes an output logic line 702 which leads by way of a light emitting diode 703 in line 704 to a positive voltage source. When the state on line 702 is false, triac 701 is turned on. This is done by sensing light from diode 703 in a photosensor SCR 705. SCR 705 is connected to an RC filter circuit 706. It is also connected by way of a full wave rectifying diode bridge 707 to the triac 701. More particularly, the line 708 is connected to the gate of triac 701 and, through capacitor 709, to line 408a. The upper terminal of bridge 707 is connected by way of line 710 to the juncture between filter capacitor 711 and filter resistor 712. The upper terminal of resistor 712 is connected to the upper elecctrode of triac 701 and by way of line 713 to the power cable 397. The transient clipper unit 714 is connected in parallel to the filters 711 and 712.
In FIG. 14 the single output circuit is shown as utilized to drive or otherwise control motor 406. Identical circuits will then be provided for controlling the application of a.c. power to the additional seven output channels 720. Since the control circuits are identical to that described for channel 702, they will not be further described.
Referring again to FIG. 1, the switch 407 is opened or closed by the position of the XY table 404. The switch 407 leads by way of cable 410 to the input unit 411 on base 401. The state of the switch 407 is employed to utilize power from cable 398 in the base 401 to signal by way of cable 399a the switch state. FIG. 14 illustrates the input circuits in one base. In this circuit, the power source is connected to the system by way of cable 398. The switch 407 is connected by way of line 410a to one of the power conductors in cable 398. The other terminal of switch 407 is connected by way of line 410b through a voltage divider comprising resistors 730 and 731 back to the other terminal of the line 398. A capacitor 732 is connected in parallel to resistor 731 to provide a filter network.
Resistors 730 and 731 drop the voltage as it is applied to full wave rectifying diode bridge 733 to about 12 volts. The bridge is connected by way of line 734 to a trigger unit 735 and thence by way of resistor 736 to a light emitting diode 737. The second terminal of diode 737 is connected by way of line 738 back to the other terminal of the bridge 733. Light emitting diode 737 is on when switch 407 is closed. When diode 737 is turned on, light therefrom is sensed by a phototransistor 739. Transistor 739 when conducting causes the state on output line 740 to be false. The other line 741 from transistor 739 is connected to ground. Thus, the circuit described in FIG. 14 serves to control the state on line 740 as to be low when switch 407 is closed.
Seven additional input lines 750 are provided in the circuit of FIG. 14 with control circuits identical to those described to control the state of output line 740.
It will be now seen that the base 400 serves as a mounting for the output unit 409. The base 401 serves as a mounting for the input unit 411.
In the circuit illustrated in FIGS. 13 and 14, an arrangement is provided wherein the logic in a single base is available for accommodating both output units such as output unit 409 and input units such as input unit 411 on the same base. In the system of FIG. 13, multiterminal plug 399c connects cable 399 into the base 400. Plug 399d serves to terminate the cable 399a in base 400. A similar plug 399e is connected into base 401 and plug 399f connects cable 399d to base 401.
In FIG. 13, line 702 and its companion lines 721 are connected to the eight inputs of two four-bit parallel-in/parallel-out shift registers 760 and 761. Registers 760 and 761 are connected by way of lines 762 to the outputs of an eight bit serial-in parallel-out shift register 763. The output data line from controller 10 connected through plug 399c to the line 764 by way of an inverter 765 to the data input terminals of register 763. The Qh output line 766 is then connected by way of inverter 767 to the output data line leading to plug 399d. Thus, a train of output data issues from the controller 10 during each half cycle of the power voltage. It enters the unit 400 and passes through shift register 763 under control of a train of clock pulses, one new bit entering for each clock pulse. The I/O clock states on line 768 are applied by way of an inverter gate 769 to the clock input terminal of shift register 763. The I/O clock line 768 is also connected to an I/O clock terminal in plug 399d. Thus, it will be recalled that when the controller 10 reads data out onto the cable 399, 256 bits are read out during each half cycle of the power voltage. The first bit read out will be stored in a register such as register 763 in the last of a series of base units located on down the cable from section 399d. The last of the 256 output bits will be stored in the first bit location in register 763.
With the I/O clock signal inhibited, the output data is then latched into registers such as register 763. During the zero crossing of the a.c. voltage in controller 10, a state is applied by way of the I/O latch line 770 through inverter 771 and line 772 to the clock terminals of the shift registers 760 and 761. This shifts the data in register 763 into the shift registers 760 and 761, thus controlling the output states on lines 702 and 721 thereby either energizing or deenergizing, as the case may be, the lines 408a and the lines 720.
Input logic line 740 and its companion lines 750 are connected into an eight bit parallel-in, serial-out shift register 775. The I/O latch state on line 770 changes from the input mode to the output mode following each train of input data to controller 10. By way of inverter 780, the states of the voltages on line 740 and lines 750 are caused serially to be read onto the line 776 and thence through inverter 777 to the input data terminal on plug 399c.
It will be noted that the input data terminal of plug 399d is connected by way of inverter 778 and line 779 to the serial input terminal of register 775. By this means, when the system is in the input mode, all of the states on lines 740 and 750 plus the states on an additional 248 similar lines in companion bases, all capable of being handled by the system, are then funneled by way of line 779 through shift register 775.
The cable leading to plug 399c has an input data line, an I/O latch line, an I/O clock line, an output data line, a +7.5 volt line, an LED power line, a set of logic ground lines and a thermal fault line.
In the embodiment above described, various integrated components were employed in the manner indicated. Logic units are indicated by conventional symbols. Other elements employed are identified as set out in Tables VII-IX.
TABLE VII______________________________________Unit______________________________________R/W memories 20, 25, 26 1024 bit R/W memory manufactured27 and 28 and sold by M.I.L. of Canada, Ottawa, Canada, Catalog No. 2102Counters 12-15, 35-39 Counter manufactured and sold byand 63 Texas Instruments Incorporated, Dallas, Texas, Catalog No. SN 74163-NROMs 30-33, 61 and 62 Processor PROM manufactured and sold by Harris Semiconductor, Inc., Melbourne, Florida and identified by Cat. No. H. PROM 1-1024-5BShift register 80 Manufactured and sold by Texas Instruments Incorporated and identified as SN 74194 NFlip-flops 21, 86, 193 Manufactured and sold by Texas213, 214 Instruments Incorporated and identified by SN 7474 NCounters 93, 95, 211, Manufactured and sold by Texas212, 226, 230 and 237 Instruments Incorporated and identified by SN 74193 NDemultiplexers 175, 177 Dual two-four line demultiplex- er, manufactured and sold by Texas Instruments Incorporated and identified by SN 74155 NMultiplexer 190 One half of a dual four-one line multiplexer manufactured and sold by Texas Instruments Incorporated and identified by SN 74153 N______________________________________
TABLE VIII______________________________________Unit______________________________________Decoders 630, 631 and Three-eight line decoder, manu-656 factured and sold by Texas Instruments Incorporated, Dallas, Texas and identified by Sn 74155NShift registers 612 Eight bit shift register, manu-and 613 factured and sold by Texas Instruments Incorporated and identified by SN 74164NCounters 624, 625 Counter manufactured and sold by Texas Instruments Incorporated and identified by SN 74177NShift registers 602- Shift register manufactured and616, 614-617 and 622 sold by Texas Instruments Incorporated and identified by SN 74195NUp/down counters 607- Binary up/down counters manu-609 factured and sold by Texas Instruments Incorporated and identified by SN 74193NUp/down counters 666- Decode up/down counters manu-668 factured and sold by Texas Instruments Incorporated and identified by SN 74192NLatch 690 Four bit latch manufactured and sold by Texas Instruments Incor- porated and identified by SN 7475NDecoder 691 BCD to seven segment decoder manu- factured and sold by Texas Instruments Incorporated and identified by SN 7448NCounter 653 Binary four bit counter manu- factured and sold by Texas Instruments Incorporated and identified by SN 74163NCounter 655 Eight to one line demultiplexer manufactured and sold by Texas Instruments Incorporated and identified by SN 74151N______________________________________
TABLE IX______________________________________Unit______________________________________Shift register 775 Eight bit parallel-in, serial- out shift register manufactured and sold by Texas Instruments Incorporated and identified by SN 74165NShift register 763 Eight bit serial-in, parallel- out shift register manufactured and sold and Texas Instruments Incorporated and identified by SN 74164NShift registers 760, 761 Four bit parallel-in, parallel- out shift register (latch) manu- factured and sold by Texas Instruments Incorporated and identified by SN 74195NCouplers 737-739 Optical coupler manufactured and sold by Texas Instruments Incor- porated and identified by TIL111SCR 703-705 Opto-SCR units manufactured and sold by Monsanto Semiconductor, Inc., Cupertino, California and identified by No. MCS 240______________________________________
The programmable logic controller with flag storage described herein is described and claimed in copending application, Ser. No. 431,589, filed Jan. 7, 1974 by Bobby George Burkett and Raymond Wilson Henry.
Program logic control with push down stack described herein is described and claimed in copending application, Ser. No. 431,538, filed Jan. 7, 1974 by Bobby George Burkett and Raymond Wilson Henry.
Having described the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.
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A programmable logic controller includes a read/write memory for storing multi bit instructions which direct computations in the controller in response to a programming keyboard module connected to the controller for encoding instructions to be stored in controller memory. Keyboard commands transfer instructions from the module to said memory in an ordered array. Instructions are read from memory serially, cyclically and non destructively for operation of the controller. A keyboard insert command inserts a new instruction at a designated address in memory and sequentially shifts each serially accessed instruction in memory stored at an address beyond the designated address to a memory address once removed.
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BACKGROUND
The present invention relates to a cargo device that carries a number of submunitions whereby the cargo device is preferably equipped with guidance and/or target seeking functions and may constitute a missile or a missile or equivalent, launchable from a ramp or other weapon platform in the form of, for example, an aircraft. The triggering or actuation of the submunitions carried shall then be determinable by a programming function on the ground or on board the weapon platform in question, such as an aircraft, or via a fixed or wireless communication link from the ground or on board said weapon platform. The submunitions shall, moreover, be actuatable either individually or jointly by means of or via an impact function, proximity fuze, remote triggering, or by another admittedly known triggering device.
The designing of missiles and other ammunition or cargo-bearing devices so that they are specially suited to combating targets or situations of a certain given type is previously known. This means that the ammunition or warhead designed for a specific type of target is often completely unsuitable for combating a different type of target, and vice versa Such dedicated ammunition units are already well known and exist in a multitude of designs, among other things because of the above mentioned target type dedication. This can be referenced in the patent literature in the field.
There is a general need to be able to reduce the assortment of weapon borne ammunition units without losing the desired effectiveness against each type of target or combat situation. The measures and ammunition units proposed must also satisfy the stringent requirements pertaining to handling, service and storage, and the matter must be characterised by singularity of purpose while safety during handling and operation must not be neglected. The objective of the present invention is to resolve this problem completely or partially.
SUMMARY
The feature that can be considered to be the main characteristic for the initially mentioned cargo device is, among other things, that the programming function incorporated comprises or interacts with mode determining devices which, for example, dependent on at least one manual or automatic actuation enables the cargo device and its submunitions to act either jointly in a penetrator mode in which the submunitions are at least essentially conjoined in a joint triggering or actuation function, or in a separation mode in which the submunitions sequentially exit their cargo space in the device and subsequently function via an individual triggering or actuation function whereby the said triggering or actuation function in each submunition can be independent of or coordinated with the triggering or actuation function of the other submunitions. In principle the same submunitions can be utilised in either mode. Alternatively, the direction of the submunitions can be determined on the ground before the cargo device starts its journey to the target, whereby the submunitions are further matched to the target and are arranged to be either conjoined in the device or for dispersal from the device according to the mode employed.
The basic principle behind the present invention is thus—as the expressions ‘penetrator mode’ and ‘separation mode’ indicate—that if penetrator mode is selected all the submunitions shall be tightly conjoined to form a single body whose combined effect provides good penetration capability in hard targets such as bunkers and which, when the cargo device reaches the target and more or less itself disintegrates against the target the conjoined submunitions continue into the target where they detonate and blow up the target from inside, or blow up the target on impact. Implementation of the penetrator mode involving a pure penetration of the target and no detonation of the submunitions until inside the target presupposes that the conjoined submunitions have a reinforced nose section which, by means of its inherent hardness and the kinetic energy acquired from the cargo device, is able to penetrate the target.
Should the reinforced nose section of the submunitions not be capable of penetrating the target, all submunitions detonate on impact with the target.
In one design version of the invention concept the mode determining devices—dependent on an additional actuation—can even be arranged to enable the cargo device and its submunitions to operate with a distributed penetrator mode in which the submunitions achieve a minor sequential dispersal and are actuated as penetration of the target progresses.
In its other main variant—separation mode—the submunitions are dispersed on command over a pre-determined target zone, and each submunition is thus actuated by its own initiation device that can be time controlled, point detonating, or have its own elementary target seeker or proximity fuze. The separation mode can be a good alternative when engaging enemy forces attacking in light armour vehicles, for example. In this variant the cargo device can even continue its flight after releasing all its submunitions. In this case the dedicated, joint nose section for penetrator mode remains in the cargo device. Dispersal of the submunitions utilises already known techniques.
Additional design versions of the present invention are disclosed in the subsequent patent claims.
The above proposals enable major technical and financial benefits by enabling a substantial reduction in the diverse range of submunition cargo devices. Well proven technical methods are used in this respect for the realisation of the present invention which means that current handling and service functions can be utilised and safety requirements can be met. As claimed in the present invention the position of the submunitions in their space in the cargo device is controlled to enable the penetrator and separation modes to be implemented. This can, of course, be achieved by using already known techniques, which further contributes to the above mentioned technical and financial benefits.
Various aspects of this disclosure relate to a cargo device ( 1 ) for submunitions ( 2 ) that is preferably equipped with guidance and/or target seeking functions ( 8 , 9 ), such as a missile, where the triggering or actuation of the submunitions is determinable by means of a programming function on the ground or on board another weapon platform (aircraft) or via wireless link from the ground or said other platform. The submunitions moreover are actuatable by impact function and/or proximity fuze function or time function wherein the programming function ( 22 ) incorporates or interacts with mode determining devices ( 18 , 19 , 20 , 21 ) which, dependent on at least one manual or automatic actuation, cause the cargo device ( 1 ) and its submunitions ( 2 ) to operate either in a penetrator mode in which the submunitions are essentially conjoined in a common triggering or actuation function, or in a separation mode in which the submunitions sequentially leave the said cargo device and thereafter function by means of an individual triggering or actuation function, each of which is either independent from or coordinated with the triggering or actuation functions of the other submunitions.
As is conventionally known in ordnance design, and as described above, submunitions may be actuated by an impact function, e.g., an impact fuze, or using a time function, e.g., a time fuze.
BRIEF DESCRIPTION OF THE DRAWING
Some of the currently proposed design forms for a cargo device displaying characteristics that are significant for the present invention are described below with reference to the appended FIGS. 1–10 in which
FIG. 1 shows a general view from the side of a cargo device in the form of a missile flying towards a target whereby the missile is operating in a penetrator mode where, for example, a hole shall be effected in the target in question,
FIG. 2 is a general side view showing the missile or equivalent in a separation mode which the missile can assume as an alternative to the penetrator mode shown in FIG. 1 , whereby the missile in separation mode has started dispensing the submunitions in question over an actual target,
FIG. 3 shows a general view from above illustrating a distributed penetrator method in which the missile or equivalent in question penetrates a building or similar target, and during penetration distributes submunitions into the various rooms or confined spaces in the building as penetration occurs,
FIG. 4 is a general view from above showing the design of a cargo device in the form of a missile,
FIG. 5 is a general end view of the missile illustrated in FIG. 4 ,
FIG. 6 is a general horizontal view showing the location of submunitions in a missile or other cargo device,
FIG. 7 is a general horizontal view showing a missile in separation mode with a submunition leaving the missile during separation, and
FIG. 8 is a general block diagram showing the programming functions for triggering and separation of the submunitions illustrated in a general manner, while
FIG. 9 is a partially cut-away longitudinal section showing the conjoined arrangement of the submunitions necessary for the penetrator mode together with their reinforced nose section, and
FIG. 10 is a partially cut-away section showing one of the submunitions after it has left the cargo device and is on its way to the target.
DETAILED DESCRIPTION
Number 1 in FIG. 1 denotes a cargo device in the form of a missile, for example. The basic design of the missile or equivalent is already well known and will not be described herein. FIG. 1 illustrates the case where the missile operates in a penetrator mode, which means that it shall impact with a target M, in the form of a bridge pier for example, and effect a hole in the target. The missile or equivalent carries or contains a number of submunitions 2 of an already known type. The submunitions may comprise explosive charges with possible associated fragment and pellet elements, or submunitions with shaped charge effect, etc. In this case the relation of the submunitions 2 to each other is selected according to the type of target represented by M. In the version illustrated in FIG. 1 the submunitions are conjoined together in the manner characteristic of the penetrator mode. The position of the submunitions inside the cargo device is shown in FIG. 4 by the designation 10 ″ and their joint reinforced nose section 10 ′ is also visible, arranged in front of the submunitions where it is mainly responsible for penetrating the target before the various submunitions detonate inside the target or complete the penetration of the target. The cargo device, which has completed its task by transporting the submunitions to the target, and which does not have the strength or hardness of the said reinforced nose section, will in most cases be simultaneously completely destroyed against the outer wall of the target while the submunitions, preceded by their reinforced nose section 10 ′, thus continue into the target.
FIG. 2 represents in general the same cargo device described in FIG. 1 . In this case the missile or equivalent is designated 1 ′. In the case illustrated in FIG. 2 the missile or equivalent is operating in a separation mode whereby the cargo device when close to the target dispenses submunitions 2 , 2 ′, 2 ″, 2 ′″, etc above or adjacent to an actual target such as a military detachment or equivalent that is not illustrated in FIG. 2 . The submunitions thereby leave their cargo space inside the missile or equivalent sequentially to enable an effective dispersion over the target in question. The dispersion can be varied via different program modes controlling the release of the submunitions from the missile or equivalent. Such program modes can be achieved by employing an already known method such as time controlled circuits.
FIG. 3 illustrates the case when the cargo device operates with a distributed penetrator method in which the cargo device 1 ″ on an approach path 3 pierces and penetrates a building 4 that can have a number of internal confined spaces or rooms of which rooms 4 a , 4 b , and 4 c are designated on FIG. 3 . It can thus be expected that penetration in the target will be performed primarily by the conjoined submunitions preceded by their common reinforced nose section. The said confined spaces in the building are bounded in a known manner by walls etc 4 a ′, 4 a ″, 4 b ′, 4 b ″, 4 c ′, 4 c ″ and so on. When the cargo device penetrates the building, cargo device 1 ″—or at least the submunitions incorporated—penetrate the said walls etc, and by using other approach paths into building 4 different walls, floors and ceilings can be penetrated. In the distributed penetrator mode as claimed in the present invention the submunitions shall be dispensed into the various rooms or confined spaces 4 a , 4 b , 4 c as the penetration of the building and its various rooms progresses. In FIG. 3 submunitions have been dispensed from the missile into rooms 4 a , 4 b , and 4 c resulting in bursts or triggerings symbolised by 5 , 6 and 7 .
FIG. 4 shows a cargo device in the form of a missile 1 ′″ of an already well known type. The missile is equipped with target seeking and guidance system equipment 8 , 9 , a motor arrangement, control surfaces, etc. As all these components are well known they will not be described in any further detail herein. FIG. 5 shows a stowage compartment 10 for submunitions that can be arranged for external release 11 of submunitions. Control of the triggering or actuation and possible release of the submunitions in distribution or separation modes is described in outline below. The submunitions 10 ″ are located inside the stowage compartment 10 arranged conjoined behind each other and behind the common reinforced nose section 10 ′ located at the front of the said compartment in the direction of flight of the carrier. Thus in penetrator mode they function during penetration of the target as a collective body but which, in distribution mode, is divided into its constituent parts—i.e. the individual submunitions—after which they are dispensed in accordance with the desired dispersion pattern.
Conjoining of the submunitions in penetrator mode and dispersal in separation mode can be performed manually or electrically. Locking devices can thereby be actuated manually or automatically via electrical control so that either mode can be enabled in conjunction with the cargo device's or vehicle's path towards the target in question. Actuation of the locking devices for locking in penetrator mode or opening in separation mode can be carried out on the ground, by wireless link from the ground, or by the weapon platform carrying the cargo device such as an aircraft, etc. Alternatively, the locking devices can be set or actuated before the cargo device is launched. In an alternative design the cargo device can in principle be loaded with different submunitions whereby the first type of submunitions are so arranged in the cargo device's cargo space that they cannot be separated, or in such a way that they can be separated. Opening of the locking devices and dispersal of the submunitions in the distributed penetrator mode can be performed in a corresponding manner to that for the separation mode. The only difference is that the sequential release of the submunitions from the cargo device shall be with closer intervals. In FIG. 6 two submunitions 11 ′ and 11 ″ are arranged in cargo device 1 ″″. More submunitions are incorporated but are not illustrated in FIG. 6 . The submunitions as such can be constructed in an already known manner. In FIG. 6 the submunitions are conjoined by symbolically designated locking devices 12 . These locking devices can be replaced by a tubular shaped outer casing that is gradually consumed during the penetrator mode, and from which the submunitions are successively ejected rearwards during the distribution mode.
FIG. 7 shows a submunition 11 ′″ released from cargo device 1 ′″″. It has been ejected rearwards from the tubular shaped carrier fuselage. Symbolically designated locking devices 12 ′ are also shown in open or release position.
In FIG. 8 a number of submunitions 13 , 14 , 15 , 16 are arranged in a symbolically displayed unit 17 . FIG. 8 also includes symbolically illustrated locking devices 18 and 19 . Locking device 18 is controllable from a control unit 20 which, when in non-actuated mode, keeps the locking devices open thereby enabling the above mentioned separation mode. For closed mode an actuation signal is received that actuates locking device 18 which thereby prevents the submunitions from leaving the cargo device 17 , thus enabling penetrator mode. Locking device 19 operates in the same way as locking device 18 in the distributed penetrator mode. Locking device 19 is controllable from control unit 21 . A programming device is designated 22 , and there is a control unit designated 23 to control the programming device. The programming device in question is used to determine the triggering and actuation functions for the submunitions. The above mentioned control unit can be incorporated in a common unit 24 .
The four tightly conjoined identical submunitions 28 – 31 illustrated in FIG. 9 for effecting the penetrator mode constitute a body 26 with a strongly reinforced nose section 27 . In the version illustrated each of these submunitions has a strong tubular shaped outer casing generally designated 28 ′– 31 ′, where each outer casing has a somewhat thinner walled front section 28 ″– 31 ″ that is bevelled under the rear section of the rear casing wall of the preceding submunition. The submunitions are conjoined by modified ball catches 28 ′″– 31 ′″ and are further equipped with integral initiation functions 28 ″″– 31 ″″ that have the dual task of releasing the submunitions from each other in separation mode. Instead of the version illustrated in FIG. 9 with the tubular outer bodies of the submunitions divisible into several units 28 ′– 31 ′, all the submunitions incorporated can be housed in a separate uniform tubular outer casing from which they are ejected rearwards in separation mode via the rear end of the cargo device relative to its direction of flight. In addition, each submunition has a parachute pack herein designated 28 ′″″– 31 ′″″ (refer also to FIG. 10 in which the parachute has deployed after completion of the separation mode). As shown in FIG. 9 each submunition 28 – 31 is filled with explosive.
FIG. 10 shows submunition 28 suspended from its parachute after a completed separation mode, descending towards the target zone where it will be triggered either by impact or by another—admittedly known—initiation function.
The present invention is not limited to the design examples illustrated above, but can be subjected to modifications within the framework of the subsequent patent claims and the invention concept.
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A selectable mode multi-mode missile carrying submunitions and incorporating guidance and target seeking functions includes triggering or actuation of the submunitions by programming function on the ground or on board another weapon platform or via a link from the ground or said the weapon platform. The submunitions may also be actuated by an impact function. The programming function incorporates or interacts with mode determining or setting devices that cause the missile and its submunitions to selectively operate either in a penetrator mode, a distributed penetrator mode, or in a separation mode. The submunitions are actuated independently, in sequence, or in common with each other depending upon the operating mode selected.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is related to U.S. patent application Ser. No. 10/426,946, filed Apr. 30, 2003, published as US 2004/0030493 A1, which is assigned to the assignee of the present patent application and whose disclosure is incorporated herein by reference.
COPYRIGHT NOTICE
[0002] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
[0003] The present invention relates generally to methods and systems for electronic download and display of maps, and specifically to route corridor maps.
BACKGROUND OF THE INVENTION
[0004] A variety of systems are known in the art for providing drivers with in-vehicle electronic routing maps and navigation aids. These systems are commonly coupled to a location-finding device in the vehicle, such as a Global Positioning System (GPS) receiver. The GPS receiver automatically determines the current location of the vehicle, to be displayed on the map and used in determining routing instructions.
[0005] In-vehicle navigation systems fall into two general categories: “on-board” systems, in which the map data are stored electronically in the vehicle (typically on optical or magnetic media) ; and “off-board” systems, in which the map data are furnished by a remote map server. Off-board systems typically use a client program running on a smart cellular telephone or personal digital assistant (PDA) in the vehicle to retrieve information from the server over a wireless link, and to display maps and provide navigation instructions to the driver.
[0006] Various off-board navigation systems are described in the patent literature. For example, the above-mentioned Patent Application Publication US 2004/0030493 A1 describes a method for displaying a map on a mobile client device. Map data, including vector information delineating features in the map, are stored on a server. The server determines a route from a starting point to a destination within an area of the map. The route includes a sequence of route segments, each having a respective length and heading angle. The server then defines a corridor map comprising a sequence of map segments, each of which contains a respective route segment and has a respective zoom level and orientation determined by the length and heading angle of the route segment. The server downloads the vector information in the map segments to the client device, which renders a succession of images of the map segments as the user travels along the route. Typically, each map segment includes crossroads that intersect the route. If the user deviates from the route, the client device displays a return path to the route on one of the crossroads.
[0007] As another example, U.S. Pat. No. 6,381,535, whose disclosure is incorporated herein by reference, describes improvements required to convert a portable radiotelephone into a mobile terminal capable of functioning as a navigational aid system. Itinerary requests of the mobile terminal are transmitted to a centralized server by a radio relay link. The server calculates the itinerary requested, and transmits the itinerary to the mobile terminal in the form of data concerning straight lines and arc segments constituting the itinerary. The server also evaluates the possibility of the vehicle deviating from its course and transmits data concerning segments of possible deviation itineraries in an area of proximity to the main itinerary.
[0008] Other off-board navigation systems are described in PCT Publications WO 01/01370 and WO 01/27812; in U.S. Pat. Nos. 6,038,559, 6,107,944, 6,233,518, 6,282,489, 6,320,518, 6,347,278, 6,381,535, 6,462,676, 6,43,630 and 6,526,284; and in U.S. Patent Application Publication 2001/0045949. The disclosures of all these patents and publications are incorporated herein by reference.
SUMMARY OF THE INVENTION
[0009] In order to assist the user of a navigation system in recovering from a deviation from the original, planned route, it is desirable to present the user with a complete, accurate picture of all the roads in the vicinity of the route. Off-board navigation systems, however, are subject to bandwidth constraints, which limit the amount of map data that can be transmitted over the air from the server to the user's client device. Therefore, the amount of ancillary road data that can be downloaded along with the actual route is severely limited.
[0010] When a user who is driving along a given route deviates onto a high-speed road, such as a freeway, he or she may have to drive a long distance before being able to return to the desired route. On the other hand, slower roads tend to have more intersections and more opportunities for maneuvering, so that a deviation onto a slower road is less likely to take the driver far away from the original route. In either case (although particularly when the driver deviates onto a high-speed road), the optimal route for the driver to take after the deviation may not be simply to return to the original route, but rather to continue traveling on a new route. Narrow corridor maps, however, are generally not capable of supporting this sort of rerouting.
[0011] In response to these shortcomings of the prior art, some embodiments of the present invention provide corridors maps having variable effective widths. In these embodiments, a server determines a route from a starting point to a destination, and downloads a corridor map of the route to a client device. In addition to the segments of the route itself, the server includes in the corridor map other roads in the vicinity of the route segments. These other roads are typically of different types, from high-speed, limited-access roads, to small, local streets. The server decides which roads to include in the map depending on the distances of the roads from the route. The map includes the roads of each type that are within a respective maximum distance from the route that is determined for that particular type of road. Typically, the maximum distance for high-speed roads is much greater than that for low-speed, smaller roads, so that the map includes high-speed roads that may be relatively far from the route, but includes low-speed roads only within a narrow range of the route.
[0012] Corridor maps that are generated in this manner can make the most of the limited available server/client bandwidth, so as to present the user with the road detail that is likely to be most useful in the event of a deviation from the original route. Furthermore, in some embodiments, the server computes optimal routes to the destination from the roads in the corridor map onto which the user may deviate from the original route. Inclusion in the corridor map of high-speed roads that are relatively far from the original route makes it possible to find and display on the client device efficient alternate routes that do not require the user simply to return to the original route.
[0013] In some embodiments of the present invention, the maximum distances for inclusion of the various road types in the corridor map have different values along different parts of the route. For example, in the vicinity of junctions along the route at which the user is likely to make a wrong turn, the maximum distances may be increased. Typically, for this purpose, the server calculates a score based on the complexity of the junction and/or the complexity of the maneuver that the user must perform at the junction. The score is used, in turn, to determine the maximum distances for inclusion of other roads in the vicinity of the junction. Additionally or alternatively, the distances may be adjusted based on the available bandwidth, whereby roads are added to the corridor map at increasingly greater distances from the route until the data volume of the map reaches a predetermined limit.
[0014] There is therefore provided, in accordance with an embodiment of the present invention, a method for displaying a map on a mobile client device, the method including:
[0015] storing map data on a server, the map data including road data with respect to roads of multiple different road types;
[0016] determining a route from a starting point to a destination within an area covered by the map data, the route including one or more route segments;
[0017] defining a corridor map on the server, the corridor map including the route segments and the roads of the different road types that are within different, respective distances, determined by the road types, of the route segments;
[0018] downloading the road data with respect to the route segments and the roads of the different road types included in the corridor map from the server to the client device; and
[0019] rendering on the client device, using the downloaded road data, one or more images, each image including at least a respective portion of the corridor map.
[0020] Typically, determining the route includes determining the route along which a user of the client device is to travel, and rendering the images includes rendering the images in a succession as the user travels along the route. In some embodiments, rendering the images includes finding position coordinates of the user using a location providing device associated with the client device, and displaying the images together with a navigation aid based on the position coordinates. In an aspect of the invention, finding the position coordinates includes receiving an initial location reading from the location providing device, and matching the initial location reading to the downloaded road data in order to find the position coordinates with respect to the corridor map. Additionally or alternatively, downloading the road data includes streaming the road data to the client device as the user travels along the route.
[0021] In disclosed embodiments, downloading the portion of the map data includes downloading the map data over a wireless link. Typically, the client device includes at least one of a cellular telephone and a personal digital assistant (PDA), which communicates with the server over a cellular telephone network that includes the wireless link. In one embodiment, downloading the road data includes downloading, together with the road data, a prompt associated with at least one of the route segments, so as to cause the client device to request updated information from the server as a user of the client device travels over the route in a vicinity of the at least one of the route segments.
[0022] In one embodiment, a classification of the roads into the different road types corresponds to expected speeds of travel on the roads. Typically, the road types include at least first and second road types, the first road type having a higher expected speed of travel than the second road type, and defining the corridor map includes incorporating in the map segments the roads of the first and second road types that are within respective first and second distances of the route segments, such that the first distance is greater than the second distance.
[0023] Typically, the road types include highways and local streets, and defining the corridor map includes incorporating in the map segments the highways that are within a first distance of the route segments and the local streets that are within a second distance of the route, such that the first distance is greater than the second distance.
[0024] In some embodiments, determining the route includes identifying junctions along the route, and associating respective measures of complexity with the junctions, and defining the corridor map includes modifying the respective distances responsively to the measures of complexity. Typically, modifying the respective distances includes increasing the respective distances in a vicinity of the junctions that are characterized as complex junctions. In one aspect of the invention, associating the respective measures of complexity includes determining a junction complexity score for each junction responsively to a topology of the junction. In another aspect of the invention, determining the route includes defining maneuvers to be performed at the junctions along the route, and associating the respective measures of complexity includes determining a maneuver complexity score for each maneuver.
[0025] In a further embodiment, defining the corridor map includes identifying junctions at which the roads included in the one or more map segments intersect with further roads of the different road types that are not within the respective distances, and adding one or more of the further roads to the one or more map segments.
[0026] In an aspect of the invention, determining the route includes determining the route along which a user of the client device is to travel, and defining the corridor map includes determining a respective path to the destination from each of at least some of the roads included in each of the map segments, and the method includes downloading the respective path to the client device in order to guide the user to the destination in the event of a deviation from the route onto one of the at least some of the roads. Typically, downloading the respective path includes associating with each of the roads in the corridor map a pointer to a subsequent road along the respective path, and downloading the pointer to the client device.
[0027] In a disclosed embodiment, the corridor map has a width that is defined at each point along the route by an extent of the roads of the different road types that are included in the corridor map in a vicinity of the point, and the width of the corridor map varies along the route responsively to the extent of the roads.
[0028] In an aspect of the invention, downloading the road data includes sorting the roads according to a respective distance of each of the roads from a location of the client device, and downloading the road data with respect to the roads in an order responsive to the distance. In one embodiment, downloading the road data includes streaming the road data to the client device in the order responsive to the distance as a user of the client device travels along the route.
[0029] In another aspect of the invention, downloading the road data includes downloading data structures that represent the roads, each data structure indicating a directional link. Each data structure may include one or more data fields indicating characteristics of the directional link selected from a group of characteristics consisting of a next link along an optimal route to the destination, a distance to the destination, and a time required to travel to the destination.
[0030] There is also provided, in accordance with an embodiment of the present invention, a method for displaying a map on a mobile client device, the method including:
[0031] storing map data on a server;
[0032] determining a route at the server from a starting point to a destination within an area covered by the map data, the route including a sequence of the directional links, in which each directional link is represented by a data structure containing a pointer to a succeeding directional link along the route;
[0033] downloading the route from the server to the client device; and
[0034] rendering on the client device, using the downloaded route, a map indicative of the route.
[0035] Typically, the method includes generating navigation instructions for a user of the client device based on the pointer in one or more of the data structures. In a disclosed embodiment, rendering the map includes rendering a maneuver map responsively to the navigation instructions. Additionally or alternatively, the method includes defining a corridor map on the server, the corridor map including the route and further directional links corresponding to other roads included in the map data in a vicinity of the route, and generating the navigation instructions includes guiding the user to the destination, responsively to the pointer in one or more of the data structures corresponding to the other roads, in the event of a deviation from the route onto one of the other roads.
[0036] In a disclosed embodiment, rendering the map includes rendering a single road segment to represent two of the directional links corresponding to opposing directions of travel on the single road segment.
[0037] In some embodiments, the method includes defining a corridor map on the server, the corridor map including the route and other roads included in the map data in a vicinity of the route, wherein downloading the route includes sorting the other roads in the corridor map according to a respective distance of each of the roads from a location of the client device, and downloading the map data with respect to the other roads in an order responsive to the distance. In an aspect of the invention, downloading the map data includes streaming the map data to the client device in the order responsive to the distance as a user of the client device travels along the route. In a disclosed embodiment, downloading the map data includes performing a breadth-first search of the other roads connecting to the starting point of the route, and downloading the map data with respect to the roads found by the breadth-first search immediately after downloading the route.
[0038] There is additionally provided, in accordance with an embodiment of the present invention, a method for displaying a map on a mobile client device, the method including:
[0039] storing map data on a server;
[0040] determining a route at the server from a starting point to a destination within an area covered by the map data, the route including a sequence of route segments;
[0041] associating a prompt with at least one of the route segments, so as to cause a client device to request updated information with respect to the route as a user of the client device travels over the route at a location associated with the at least one of the route segments;
[0042] downloading the route segments from the server to the client device;
[0043] rendering on the client device, using the downloaded route segments, a map indicative of the route; and
[0044] responsively to the prompt, receiving a request from the client device for the updated information, and providing the updated information with respect to the route.
[0045] Typically, downloading the route segments includes downloading data to the client device over a wireless link, and receiving the request includes receiving a communication initiated by the client device over the wireless link. In a disclosed embodiment, receiving the communication includes receiving a Hypertext Transfer Protocol (HTTP) request, and providing the updated information includes sending a HTTP response.
[0046] Providing the updated information may include informing the client device of a change in the route.
[0047] There is further provided, in accordance with an embodiment of the present invention, apparatus for displaying a map on a mobile client device, the apparatus including:
[0048] a memory, which is arranged to store map data, including road data with respect to roads of multiple different road types; and
[0049] a server, which is adapted to determine a route from a starting point to a destination within an area covered by the map data, the route including one or more route segments, and which is adapted to define a corridor map including the route segments and the roads of the different road types that are within different, respective distances, determined by the road types, of the route segments, and to download the road data with respect to the route segments and the roads of the different road types included in the corridor map to the client device so as to enable the client device, using the downloaded road data, to render one or more images, each image including at least a respective portion of the corridor map.
[0050] There is moreover provided, in accordance with an embodiment of the present invention, apparatus for displaying a map on a mobile client device, the apparatus including:
[0051] a memory, which is arranged to store map data;
[0052] a server, which is adapted to determine a route from a starting point to a destination within an area covered by the map data, the route including a sequence of the directional links, in which each directional link is represented by a data structure containing a pointer to a succeeding directional link along the route, and to download the route to the client device, so as to enable the client device, using the downloaded route, to render a map indicative of the route.
[0053] There is furthermore provided, in accordance with an embodiment of the present invention, apparatus for displaying a map on a mobile client device, the apparatus including:
[0054] a memory, which is arranged to store map data;
[0055] a client device; and
[0056] a server, which is adapted to determine a route from a starting point to a destination within an area covered by the map data, the route including a sequence of route segments, and to associate a prompt with at least one of the route segments, so as to cause the client device to request updated information with respect to the route as a user of the client device travels over the route at a location associated with the at least one of the route segments, and which is coupled to download the route segments to the client device,
[0057] wherein the client device is adapted to render an image of a map indicative of the route, using the downloaded route segments, and is further adapted, responsively to the prompt, to submit a request to the server for the updated information, and wherein the server is adapted to provide the updated information with respect to the route in response to the request.
[0058] There is also provided, in accordance with an embodiment of the present invention, a computer software product for displaying a map on a mobile client device, the product including a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to read map data, including road data with respect to roads of multiple different road types, and to determine a route from a starting point to a destination within an area covered by the map data, the route including one or more route segments, the instructions further causing the computer to define a corridor map including the route segments and the roads of the different road types that are within different, respective distances, determined by the road types, of the route segments, and to download the road data with respect to the route segments and the roads of the different road types included in the corridor map to the client device so as to enable the client device, using the downloaded road data, to render one or more images, each image including at least a respective portion of the corridor map.
[0059] There is additionally provided, in accordance with an embodiment of the present invention, a computer software product for displaying a map on a mobile client device, the product including a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to read map data, and to determine a route from a starting point to a destination within an area covered by the map data, the route including a sequence of the directional links, in which each directional link is represented by a data structure containing a pointer to a succeeding directional link along the route, and to download the route to the client device, so as to enable the client device, using the downloaded route, to render a map indicative of the route.
[0060] There is further provided, in accordance with an embodiment of the present invention, a computer software product for displaying a map on a mobile client device, the product including a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to read map data and to determine a route from a starting point to a destination within an area covered by the map data, the route including a sequence of route segments, and to associate a prompt with at least one of the route segments, so as to cause the client device to request updated information with respect to the route as a user of the client device travels over the route at a location associated with the at least one of the route segments, and to download the route segments to the client device so as to enable the client device to render an image of a map indicative of the route, using the downloaded route segments, the instructions further causing the computer to receive, responsively to the prompt, a request from the client device for the updated information, and to provide the updated information with respect to the route in response to the request.
[0061] The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] FIG. 1 is a simplified pictorial illustration of a real-time map distribution and display system constructed and operative in accordance with an embodiment of the present invention;
[0063] FIG. 2 is a schematic representation of a screen displayed on a client device in a vehicle, showing a map and directions generated by the system of FIG. 1 , in accordance with an embodiment of the present invention;
[0064] FIG. 3 is a graph that schematically illustrates elements of a route corridor map generated by a mobile device based on map data furnished by a mapping server, in accordance with an embodiment of the present invention;
[0065] FIG. 4 is a schematic representation of a segment of a route corridor map, in accordance with an embodiment of the present invention;
[0066] FIG. 5 is a flow chart that schematically illustrates a method for generating a route corridor map in accordance with an embodiment of the present invention;
[0067] FIG. 6 is a flow chart that schematically illustrates a method for determining a distance within which roads are to be included in a route corridor map, in accordance with an embodiment of the present invention;
[0068] FIG. 7 is a schematic representation of a route corridor map, generated in accordance with an embodiment of the present invention; and
[0069] FIG. 8 is a flow chart that schematically illustrates a method for downloading map data to a client, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0070] FIG. 1 is a simplified pictorial illustration of a real-time map distribution and display system 20 , constructed and operative in accordance with an embodiment of the present invention. As seen in FIG. 1 , a driver of a vehicle 22 communicates with a map server 28 via a client device 24 , typically a wireless communicator, such as a personal digital assistant (PDA) 24 having cellular telephone functionality or a smart cellular telephone. Optionally, PDA 24 communicates with server 28 via an interactive voice response (IVR) processor and/or via the Internet. Server 28 typically comprises a general-purpose computer, comprising a memory in which map data are stored and processor, which carries out the methods described herein under the control of software. The software may be downloaded to the processor in electronic form, over a network, for example, or it may alternatively be provided on tangible media, such as CD-ROM, DVD, magnetic media or non-volatile memory.
[0071] A location data output is provided by a GPS receiver 26 or other locating device in the vehicle, and the location is transmitted automatically by client device 24 to server 28 . Alternatively, a cellular network with which client device 24 communicates may provide the location data output to server 28 , or the user may supply location data via the client device.
[0072] In the illustrated embodiment, the driver of vehicle 22 asks for current directions and a map showing a route from his current location to a given destination. Map server 28 computes the preferred route to the destination, and then generates a corridor map showing the route. The corridor map comprises map data, typically in the form of vector data, which delineates the route, along with other roads in the vicinity of the route. Based on the map data, a client program running on client device 24 renders a map showing the preferred route on a display 30 . Methods for generating a corridor map using vector data, and for rendering the map on a client device, are described further in the above-mentioned U.S. patent application Ser. No. 10/426,946. In system 20 , the roads to be included in the map data are chosen based on the road types and the distances of the roads from the route, wherein different maximum distances for road inclusion are applied to different road types. This aspect of the present invention is described further hereinbelow.
[0073] Typically, client device 24 outputs navigation instructions to the driver, based on the route calculated by server 28 . The navigation instructions are generally shown on display 30 along with the map, and they may also be enunciated by the client device using text-to-speech functionality. In addition, server 28 may calculate alternate routes to the destination, to be followed in case vehicle 22 deviates from the original route, and may download these alternate routes to client device 24 along with the map data. For example, assuming the original route to the destination to be Route 1, as shown in the figure, the user may mistakenly turn right off the route. In this case, based on the alternate route downloaded from server 28 , client device 24 may instruct the user to turn left onto Route 2, and to continue in this manner to the destination rather than attempting to return to Route 1. This alternate routing is made possible by the selective inclusion in the map data of the additional roads that are in the vicinity of the original route. Additionally or alternatively, client device 24 may use the map data in computing alternate routes in the event of a wrong turn.
[0074] FIG. 2 is a schematic representation of display 30 , showing a map displayed by the client program running on client device 24 in the course of a trip in vehicle 22 , in accordance with an embodiment of the present invention. This map is one of a sequence of maps displayed in succession in the course of the trip, each showing a successive part of the route corridor depending on the current location of the vehicle. An icon 32 shows the current position of vehicle 22 on a road 34 that is part of the route. Because of limitations in the accuracy of GPS receiver 26 , client device 24 may correct the position coordinates provided by the receiver to show the true location of vehicle 22 relative to the map shown on display 30 . The route provided by map server 28 is marked by highlighting. The display provides driving directions (“turn left”) with respect to a junction 36 that the vehicle is approaching, as well as other textual information. These display features are further described in the above-mentioned U.S. patent application Ser. No. 10/42.6,946.
[0075] FIG. 3 is a graph that schematically illustrates a route 40 generated by server 28 , in accordance with an embodiment of the present invention. This figure also shows aspects of a route corridor map for route 40 , as described below with reference to the figures that follow. Route 40 has the form of a directed polyline, comprising a sequence of links 44 , 46 , 48 , 50 , 52 that connect a route origin 42 to a destination 43 . The links correspond to roads, which run between junctions 54 , 56 , 58 , 60 and the origin and destination nodes. The junctions typically correspond to road intersections or interchanges. Route 40 may also comprise an identification of side roads that intersect the designated route at the junctions, represented in FIG. 3 by links 61 , 63 , 65 and 66 . Other road features and landmarks along the route may be identified, as well.
[0076] Construction of route 40 by server 28 is described generally in the above-mentioned U.S. patent application Ser. No. 10/426,946. To summarize briefly, client device 24 submits a route request that specifies various input data, such as the starting location (provided by manual input or automatically, by GPS 26 , for example) and destination, as well as any interim locations to be passed along the route. The user may also specify a choice of optimal route type (shortest, fastest or simplest), as well as the transport type (car, truck, bicycle, pedestrian), and any road types to avoid (for example, toll roads). The server then computes the route, using any suitable automatic routing algorithm known in the art, such as the A*, Floyd-Warshall or Dijkstra algorithm. Such algorithms are described, for example, by Cherkassky et al., in “Shortest Path Algorithms: Theory and Experimental Evaluation,” Technical Report 93-1480, Department of Computer Science, Stanford University (Stanford, Calif., 1993), which is incorporated herein by reference.
[0077] The methods of constructing and downloading route 40 provided by embodiments of the present invention differ from methods known in the art in a number of important particulars. In mapping systems known in the art, road data are represented in terms of road segments and nodes, wherever two or more segments meet. Route 40 , however, is build up from directed segments, referred to herein as links. In other words, as shown in FIG. 3 , a segment 64 of a two-way road comprises two links, such as links 46 and 63 shown in the figure. Each link corresponds to a data structure that includes, in addition to a respective origin and end point, other data fields computed by server 28 in the course of constructing the route and indicating characteristics of the link, for example:
Link index (or link ID). Note that the indices of opposing links belonging to the same two-way road segment are keyed so that client device 24 draws only a single road when rendering a map containing the links. A pointer to the next link along the optimal route to destination 43 (except for the final link, in which the pointer is null). Thus, link 46 will contain a reference to link 48 . Link 62 , on the other hand (where the driver may find himself in the event of a wrong turn at junction 54 ) will contain a pointer to link 65 . This aspect of the link structure facilitates instantaneous rerouting in the event that the driver leaves the original route, without the need for additional computations. Route change prompts 67 . These prompts comprise instructions to the mapping program on client device 24 to contact server 28 for possible changes to route 40 during the trip. Such changes may occur, for example, due to changing traffic conditions of which the server is informed. Prompts 67 may be placed anywhere along the route, but are most commonly located shortly before decision points (such as whether to take a given bridge or a tunnel to cross a river). Typically, each prompt 67 causes the client device to send a HTTP request to the server. Although it would also be possible for the server to push updates to the client, this sort of functionality is not supported by the HTTP client/server environment. Strategic placement of prompts 67 along the route ensures that the client device will receive timely information, without wasting bandwidth on unnecessary communications. Distance and time to destination, to be shown on display 30 (as in the lower right corner of FIG. 2 , for example). Other landmarks, buildings and features of interest along the route (not shown in the figures).
An exemplary listing of link and segment data structures, which include some of the data fields described above, is provided in Appendix A.
[0083] Based on the computed route, server 28 may build a list of maneuvers that will be required along the route. Each maneuver indicates an action to be taken by the user of client device 24 at one of the junctions along the route. The list of maneuvers is downloaded to the client device along with the route itself. The client program on client device 24 may use the information in the maneuver list to prepare suitable verbal instructions for the user (for example, “right turn in 300 m,” followed by “right turn in 50 m,” followed by “now turn right”) Alternatively, based on the next-link pointers provided as part of route 40 , the client device may generate the instructions itself.
[0084] To accompany the route itself, server 28 generates a corridor map containing the route. As shown in the figures that follow, the corridor map is actually made up the road segments corresponding to links 44 , 46 , 48 , 50 , 52 of route 40 , along with certain roads on either side of the route. The map contents are downloaded incrementally to client device 24 as vehicle 22 proceeds along route 40 , typically as described hereinbelow with reference to FIG. 8 , and are rendered by the client device to display 30 . The actual boundaries of the road data contained in the corridor map are variable, and the corridor may have different widths for different types of roads. This feature of the present invention is illustrated in FIG. 4 . In rendering a given segment of the corridor map to display 30 , client device 24 may show the entire width of the corridor, including all roads in the map, or it may show only a portion of the segment map depending on the zoom factor used in rendering the map at any given point. In the map shown in FIG. 2 , for example, a high zoom factor (high magnification) is used in order to present details of a junction at which a maneuver is to take place.
[0085] Thus, to summarize, the route and corridor map data downloaded by server 28 to client device 24 permit the client device to perform a number of different mapping and guidance functions, including:
Full map rendering. Rendering of maneuver maps (as shown in FIG. 2 ). Instruction building. Local rerouting in case of deviation from the route. Dynamic route updates. Map matching—correction of errors in reading of GPS receiver 26 so as to determine the precise location of vehicle 22 on one of the links in the route.
Methods of map matching are described further in the above-mentioned U.S. patent application Ser. No. 10/426,946. Thus, although the methods and data structures described above are particularly useful in relation to downloading and rendering of corridor maps, it will be understood that these methods and data structures are useful in other aspects of navigation and map rendering, as well.
[0092] FIG. 4 is a schematic, enlarged view of a segment 69 of the corridor map corresponding to route 40 , in accordance with an embodiment of the present invention. The segment map in this example contains roads of four types: high-speed, limited-access roads 70 (type 0), highways 72 (type 1), primary local roads 74 (type 2) and secondary local roads (type 3). These types of roads have been chosen solely by way of example, and server 28 may alternatively be configured to handle a larger number of road types. Link 50 of route 40 within segment map 69 follows a type 0 road between junctions 58 and 60 , as shown by arrows 78 .
[0093] Segment map 69 includes all roads of each type that are accessible from link 50 and are within a certain maximum distance of the route segment. The “distance” of a given road from link 50 is typically measured as the road distance from the link to the closest point on the given road. Alternatively, other distance measures may be used. The maximum distance that is used to determine which roads to include in the segment map depends on the type of road. Typically, the maximum distance varies inversely with the expected road speed, i.e., the lower the type number (in the typing scheme described above), the larger the distance. Thus, all type 0 roads that fall within a large distance 80 of link 50 are included in segment map 66 . Types 1, 2 and 3 roads are included only if they fall within successively smaller distances 82 , 84 , 86 of link 50 .
[0094] By virtue of including side roads in segment map 69 in this manner, it is possible for server 28 to compute alternate routes to destination 43 , for use in case vehicle 22 deviates from the original route. Such alternate routes are not limited to returning the vehicle to the route segment from which it deviated, but may rather direct the user along another, parallel route that has become the optimal route (over all the roads included in the corridor map) in view of the deviation from the original route. Thus, for example, the server may precompute an alternate route 88 , to be taken in case vehicle 22 takes a wrong turn at junction 58 . The results of the alternate route computation may be recorded in the next-link pointers of the links along route 88 , as described above. Client device 24 will then prompt the user to proceed along road 72 in order to rejoin the original route at the next link 52 .
[0095] FIG. 5 is a flow chart that schematically illustrates a method for generating a route corridor map, in accordance with an embodiment of the present invention. Server 28 receives a route request input from the client device, and computes an optimal route from origin 42 to destination 43 , at a route computation step 90 . This step may use any suitable routing algorithm known in the art, as described above. In the succeeding steps, for each link in the route, the server adds roads of each different type that are in the vicinity of the route. In the present example, the types are identified as type 0 (fastest) through type N Max (slowest). The server in this example begins from the slowest type.
[0096] For each road type, the server sets the corridor width equal to a maximum distance measure chosen for that road type, DIST N , at a width setting step 92 . This distance, as noted above, represents the road distance from the route to the nearest point on the road in question. For example, given road types 0 through 5, the widths may be set as follows:
DIST 5 =200 m DIST 4 =500 m DIST 3 =1000 m DIST 2 =2000 m DIST 1 =10 km DIST 0 =50 km
It will be understood that these values are shown here by way of example, and it is similarly possible to use a larger or smaller number of road types, and larger or smaller maximum distances. The distance values may be set separately for different segments of route 40 , depending on the density of side roads in the vicinity of each route segment and/or the type of road along which the route runs in each segment, for example. Furthermore, the maximum distances may be varied adaptively, as described below with reference to FIG. 6 .
[0103] For each road type N, server 28 collects all roads that are within DIST N of the route, at a road collection step 94 . For this purpose, the server typically searches its own database of map data. Either a breadth-first or a depth-first search may be used. Optionally, a maximum data size for each map segment may be set, and further roads may be added to the map segment if it has not reached this maximum size after collecting the roads of all types on a first pass through step 94 . In this case, for example, the maximum distances DIST N for some or all of the road types may be increased, and step 94 may then be repeated. Alternatively, step 94 may be repeated iteratively with respect to the roads added in the first pass through step 94 , so as to add further roads of some or all of the types that are within the respective maximum distances of the roads added in the first pass. Such iterations may continue until the data size of the map segment reaches the maximum data size, or until there are no more roads to add to the map segment.
[0104] After it has finished adding all appropriate roads to the corridor map, server 28 optionally computes alternate routes to destination 43 over these added roads, at an alternate routing step 96 . The same routing algorithms that were used at step 90 may be used at step 96 , as well. Each such route starts from one of the roads added at step 94 (represented as a link with a given direction heading), and finds an optimal path to destination 43 over any of the roads in the corridor map, not necessarily on the original route 40 . Route 88 ( FIG. 4 ) is one example of such an alternate route.
[0105] After the complete corridor map has been constructed, server 28 downloads the map data to client device 24 , at a download step 98 . Typically, the server downloads the map data gradually, in order not to overload the limited memory capacity of the client device and to use the available wireless bandwidth efficiently. Details of download step 98 are described hereinbelow with reference to FIG. 8 . The client device then displays the appropriate map segment, along with the applicable driving instructions, as the vehicle travels over the segment.
[0106] FIG. 6 is a flow chart that schematically illustrates a method for determining variable maximum distances, DIST N *, for use at steps 92 and 94 of the method of FIG. 5 , in accordance with an embodiment of the present invention. In general, users of system 20 are likely to deviate from the routes determined by server 28 only at junctions along the route, and most commonly in complex junctions and junctions at which the user must make a complex maneuver. Therefore, the method of FIG. 6 permits the route corridor to be widened adaptively in the vicinity of such junctions, by increasing DIST N * for some or all of the road types 0 through N Max .
[0107] Server 28 scans each link along route 40 that it has determined in order to determine where the junctions along the route are located, at a junction location step 100 . If a link contains so significant junction, server 28 simply uses the default DIST N , at a default step 102 .
[0108] Upon locating a junction, server 28 calculates a junction complexity score, at a junction scoring step 104 . This score reflects the topological complexity of the junction itself. Factors that affect the junction complexity score include, for example:
Size of the junction. The number of incoming and outgoing roads in the junction. The number of different lanes in the road. The angle difference between the destination road (on which the user is to exit the junction) and the roads neighboring the destination road. The angle of the destination road relative to the road on which the user enters the junction. (This element of the score depends on how well the angle of the destination road matches the user's intuitive perception of the maneuver instruction to be given at the junction. For example, if a turn onto the destination road is required, how close is the turn to 90°? If no turn is required, is the destination road straight relative to the entry road, or does it turn?) How major is the destination road compared to the other outgoing roads from the junction.
Other scoring factors will be apparent to those skilled in the art. The junction score is determined by an empirical formula, typically based on the points above.
[0115] Server 28 next calculates a maneuver complexity score for the junction, at a maneuver scoring step 106 . This score is defined by the type of action the user must perform at the junction, and the conditions under which the action is to be taken. For example, simple maneuvers such as “continue straight,” or “at the end of the road turn right/left,” may get the lowest complexity grade. Maneuvers such as “turn right/left” or “keep right/left” or simple entry to or exit from a traffic circle may get a higher complexity grade, while complex maneuvers such as “make a U-turn” or negotiating complicated traffic circles and interchanges may get a still higher grade.
[0116] Conditions that may affect the complexity score include, for example, the driving speed during the maneuver, whether the user is driving in daylight or at night, and the distances between the previous maneuver and the current maneuver, and between the current maneuver and the next one. Closely-spaced maneuvers become inherently more complex. For instance, “turn right and the immediately right again” is a highly-complex maneuver, although it is made up of two maneuvers that are themselves of only intermediate complexity. The maneuver complexity score is determined by the inherent complexity of the maneuver type, weighted by any conditions that make the maneuver more difficult.
[0117] Server 28 calculates the total junction score, at a distance determination step 108 . The total score is found by combining the junction complexity and maneuver complexity scores found at steps 104 and 106 , typically by taking a weighted sum or mean of the scores. The maximum distances, DIST N *, to be used in collecting different road types are determined by increasing the default distances, DIST N , by an amount that depends on the total junction score—the greater the score, the larger DIST N *. Construction of the corridor map then proceeds at step 94 using the increased distances.
[0118] FIG. 7 is a corridor map 110 constructed in accordance with an embodiment of the present invention, using the procedures described above. Route 40 is shown as a bold line, leading from origin 42 to destination 43 . The corridor surrounding the route contains side roads 112 , 114 , 116 of different types. Note the variation in corridor width along the length of the route.
[0119] FIG. 8 is a flow chart that schematically shows details of download step 98 ( FIG. 5 ), in accordance with an embodiment of the present invention. The method of FIG. 8 is designed to permit the driver of vehicle 22 to start out along route 40 within a short time of requesting the route—typically less than 10 sec, and to provide the required map data to client device 24 gradually as the vehicle proceeds along the route. In other words, the order of downloading the map data is chosen so that the “graphic horizon,” i.e., the level of available detail, advances along the route ahead of the vehicle, and the client device has detailed information available when needed. These objectives are met within the constraints of the narrow-bandwidth wireless link between the client device and the server.
[0120] After computing route 40 and the route corridor, server 28 performs a breadth-first search to collect all road segments that are connected to origin 42 of the route, at an origin searching step 122 . The server downloads the map data with respect to these nearby road segments so that the client device can provide the driver with a complete map of his initial surroundings before he starts traveling. As noted above, steps 120 and 122 are typically completed within about 10 sec or less of submission of the route request by the user. The detailed local map-provided following step 122 is useful in avoiding initial driver errors that are very common at the beginning of the route.
[0121] Server 28 then sorts the remaining road segments in the corridor map (which it has typically assembled in accordance with the method of FIG. 5 described above) according to the distance of the segments from the current location of vehicle 22 , at a distance sorting step 124 . Typically, the distance can be measured either in Cartesian terms or in terms of road distance to each segment. The sort may be updated from time to time as the vehicle travels along the route. The server then streams the map data to client device 24 according to the sort order, starting from the segments closest to the current vehicle location, at a data streaming step 126 . Typically, the server streams the data continuously until the entire corridor map has been downloaded to the client device. Alternatively, if the memory of the client device is insufficient to hold the entire corridor map, or if bandwidth constraints make continuous streaming impractical, the server may download the map data in pieces, in response to the location of the vehicle along the route.
[0122] It will be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
APPENDIX A LINK AND SEGMENT DATA STRUCTURES /** * <b>Title:</b> * Link<br> * <b>Description:</b> * Class describing all directional data of a segment. * Each <code>Link</code> object is tightly related to a * <code>Segment</code> object. <code>Link</code> object * holds road connectivity data. * <br> */ public class Link { /** * ID of the segment to which this link relates. */ public int m_segID; /** * ID of this link. If this link is in the related * segment's geometry direction, then *<code>m_linkID</code> equals <code>m_segID</code>. * Else, <code>m_linkID</code> equals <code>m_segID * −1</code>. */ public int m_linkID; /** * Number of successors. */ public int m_numSuccessors; /** * ID's for successors of this link. * ID's are of <code>Link</code> object. * <code>m_numSuccessors</code> should be considered * as the array's length. */ public int[ ] m_successors; /** * Determines if successor is physically connected * to this link (are the roads ‘touching’, or is it * a bridge or a tunnel) . * <code>m_numSuccessors</code> should be considered * as the array's length. */ public boolean[ ] m_isPhysicallyConnected; /** * Determines if successor is legally accessible * from this link. * <code>m_numSuccessors</code> should be considered * as the array's length. */ public boolean[ ] m_isAccessible; /** * ID of the next link on this route. */ public int m_nextLink; /** * Instruction code for the instruction from this * link to the link described by * <code>m_nextLink</code>. */ public byte m_instructions; /** * Distance to route's destination (in meters) from * the beginning of this segment; −1 if link doesn't * reach destination or no route available. */ public int m_distanceToDestination; /** * Estimated time to destination (in seconds) from * the beginning of this segment; −1 if link doesn't * reach destination or no route available. */ public int m_timeToDestination; /** * Indicates if link is part of the main route * calculated by the server around which corridor is * built. */ public boolean m_isMainRoute; /** * Indicates whether this link is a full link, * meaning its <code>m_nextLink</code>, * <code>m_instructions</code>, * <code>m_distanceToDestination</code>, and * <code>m_timeToDestination</code> are valid. */ public boolean m_isFullLink; /** * Indicates whether vehicle can navigate on this * link. */ public boolean m_isNavigable; /** * Indicates whether this link is at the border of * the corridor. */ public boolean m_isBorder; /** * Indicates whether this link has a physical * divider (e.g.: a fence)at its end. If a link has * a physical divider then all its left (in UK:) * right successors that are not accessible should * be considered blocked by the divider. */ public boolean m_hasPhysicalDivider; } /** * <b>Title:</b> * Segment<br> * <b>Description:</b> * Class describing a segment on the road grid. A segment * is defined as part of a road between two consecutive * intersections. Intersections can be physical or not * (bridges, tunnels). Segment may also start or end if * road's name is changed. This class holds all the * geographical & visual data of the segment, that is not * direction-dependant. * <br> */ public class Segment { public static final int INVALID_ID = 0; /** * Road types */ public static final byte RT_FIRST_VALUE = 1, * indicates value of first road type RT_MAJOR_HIGHWAY = 1, RT_HIGHWAY = 2, RT_SECONDARY_HIGHWAY = 3, RT_MAIN_ROAD = 4, RT_STREET = 5, RT_PEDESTRIAN = 6, RT_LAST_VALUE = 7 * indicates the value of last road type + 1 /** * Visual types */ public static final byte VT_NORMAL = 0, VT_TUNNEL = 1, VT_FERRY = 2, VT_BRIDGE1 = 3, VT_ROUNDABOUT = 4, VT_RAMP = 5, VT_CONNECTOR = 6, VT_BRIDGE2 = 7, VT_BRIDGE3 = 8, VT_UNDERPASS = 9; public static final int SEG_ID_MASK = 0x7FFFFFFF; /** * ID of this segment. * ID is unique in a route scope. */ public int m_segID; /** * Geometry of this segment. * Contains all the ‘X’ values of the polyline * points, in meters, relative to route's origin * point. Array is not necessarily full - there may * be some junk data at its end. Actual number of * relevant points is <code>m_nPoints</code>. */ public int[ ] m_xPoints; /** * Geometry of this segment. * Contains all the ‘Y’ values of the polyline * points, in meters,relative to route's origin * point. Array is not necessarily full - there may * be some junk data at its end. Actual number of * relevant points is <code>m_nPoints</code>. */ public int[ ] m_yPoints; /** * Actual number of points in <code>m_xPoints</code> * and <code>m_yPoints</code> (must be identical). */ public int m_nPoints; /** * Distance at segment-start (in meters) which is * actually part of the junction. */ public int m_startPointMargin; /** * Distance at segment-end (in meters) which is * actually part of the junction. */ public int m_endPointMargin; /** * Reference to labels char array. Segment's name is * in this array, from index * <code>m_labelStart</code> until the null * terminator. */ public byte[ ] m_label; /** * Starting position of label within * <code>m_label</code>. */ public int m_labelStart; /** * Indicates whether this segment is a ‘black- * segment’, meaning segment * with highly generalized geometry. */ public boolean m_isBlackSeg; /** * Link related to this segments, with the same * direction as this segment's geometry. May be * null if link in that direction doesn't exist. */ public Link m_forwardLink = null; /** * Link related to this segments, with a direction * opposite to this segment's geometry. May be * null if link in that direction doesn't exist. * */ public Link m_backwardLink = null; /** * Default constructor */ }
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A method for displaying a map on a mobile client device. The method includes storing map data on a server, the map data including road data with respect to roads of multiple different road types. The server determines a route from a starting point to a destination within an area covered by the map data, the route including one or more route segments. The server defines a corridor map including the route segments and the roads of the different road types that are within different, respective distances, determined by the road types, of the route segments. The server downloads the road data with respect to the route segments and the roads of the different road types included in the corridor map to the client device. The client device, using the downloaded road data, renders one or more images, each image comprising at least a respective portion of the corridor map.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. application Ser. No. 09/663,687, filed Sep. 19, 2000, which claim priority from Japanese Patent Application No. 11-305593, filed Oct. 27, 1999, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method and apparatus for printing electronic document data containing a large amount of image data such as graphic images on a sheet of paper, and restoring the original electronic document data based on the data printed on the sheet of paper.
[0003] There has been conventionally known an apparatus for reading data printed on a paper sheet through a scanner and creating electronic document data including characters and images, for example, in order to reuse the contents of the documents printed on the distributed sheet of paper.
[0004] Jpn. Pat. Appln. KOKAI Publication No. 10-224540 discloses a digital copier which creates electronic document data by recognizing code patterns which are easy to read for computers such as griff code (Xerox USA) and bar codes and printed on paper.
[0005] Such conventional systems however take a long time to recognize characters and still cannot recognize 100% of the letters. As a result, inaccurate electronic document data are created.
[0006] Moreover, if the print data to be converted to electronic data contain e.g. color images and thus the amounts of data are large, it may be difficult to print all the code patterns corresponding to the entire print data on e.g. the back of the sheet. In such a case, it is impossible to create electronic document data.
[0007] Thus, in a conventional arrangement, it is difficult to restore electronic document data if the print data containing e.g. color images and thus all the code patterns corresponding to the entire print data cannot be printed.
BRIEF SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide an image processing apparatus and a method which can restore electronic document data including image data such as color graphics and thus large in data size and thus makes it possible to raise the upper limit of the size of electronic document data as an original of paper document distributed.
[0009] According to the present invention, there is provided an image forming apparatus comprising: a controller for determining whether or not document data given have a capacity larger than a first predetermined value; a first code pattern creating portion for creating code patterns by encoding the document data if the controller determines that the document data have a greater capacity than the first predetermined value; a reducing portion for reducing the document data by a second predetermined value if the controller determines that the document data have a greater capacity than the first predetermined value; a second code pattern creating portion for encoding the document data reduced by the reducing portion to create code patterns; and a print function for forming images on a recording medium based on the code patterns created by at least one of the first code pattern creating portion and the second code pattern creating portion.
[0010] With this arrangement, even if document data including e.g. image data cannot be converted to printable code patterns because the document data are too large in size, the image data are deleted with only the document data retained. Thus, it is possible to print only the document data on the front side of the sheet, and print code patterns such as bar codes corresponding to the document data on the back of the sheet.
[0011] From another aspect of the invention, there is provided an image forming apparatus comprising: a scanner for reading code patterns on a recording medium; a creating portion for recognizing the code patterns read by the scanner and creating temporary document data based the code patterns; a controller for determining whether or not predetermined image data have been deleted based on the code patterns recognized by the creating portion; a controller for determining the temporary document data created by the creating portion as final document data if the controller determines that no data have been deleted from the code patterns; and a supplementing portion for restoring predetermined data from data other than the code patterns and incorporating the restored predetermined data into the temporary document data created by the creating portion to restore the final document data if the controller determines that the predetermined data have been deleted from the code patterns.
[0012] The present invention also provides an image processing apparatus for reading the code patterns printed on the back of the sheet of paper and judging whether or not data such as image data have been deleted when the code patterns are printed by the abovementioned image forming apparatus. If image data are determined to have been deleted, the images printed on the front side of the sheet are read and incorporated into the code patterns obtained from the code patterns. With this arrangement, it is possible to print or store even document data containing image data, which were heretofore been unhandlable, through code patterns such as bar codes.
[0013] The image forming apparatus and the image processing apparatus according to the present invention can be used for the image forming method and image processing method of the present invention.
[0014] Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0015] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
[0016] FIG. 1 is a block diagram schematically showing an image processing system according to an embodiment of the present invention;
[0017] FIGS. 2A and 2B show an example of a paper document printed and output by the image processing apparatus;
[0018] FIG. 3 shows an example of electronic document data;
[0019] FIG. 4 is a detailed block diagram of the image processing apparatus;
[0020] FIG. 5 is a flowchart showing the printing processing of electronic document data in the image processing apparatus;
[0021] FIG. 6 is shows electronic document data with the image data deleted; and
[0022] FIG. 7 is a flowchart showing the creating processing of electronic document data in the image processing apparatus.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The embodiment of the invention is now described with reference to the drawings.
[0024] FIG. 1 schematically shows a configuration of an image processing system according to an embodiment of the present invention. The system comprises e.g. a general-purpose computer (hereinafter simply referred to as “personal computer”) 1 , and an image processing device 2 . They are connected together by a network 3 .
[0025] The personal computer 1 creates electronic document data by activating a word processor based on built-in application software, and also activates a display and the image processing device 2 to print data. The word processor of the personal computer 1 is not described because it is already well-known in the art.
[0026] The image processing device 2 prints electronic document data created by the personal computer 1 on a printing medium, i.e. sheets of paper, and creates electronic document data based on a printed paper document 4 .
[0027] FIGS. 2A and 2B show an example of paper document 4 printed by the image processing device 2 . FIG. 2A shows the front side, on which are printed human-recognizable document data such as character data 5 and image data 6 , e.g. color graphics. FIG. 2B shows the back side of the sheet, on which are printed code patterns 7 which can be recognized by the image processing device 2 to create electronic document data. The code patterns 7 are e.g. one- or two-dimensional bar codes or griff code (trademark of Xerox USA).
[0028] While electronic document data are available in various formats, description is made here with reference to an example shown in FIG. 3 . In this example, the image portion (image data) consists of 20000×2000 pixels with each pixel representing one byte (256 colors). The data size of the image data portion is therefore 4 Mbytes. The data size of the other portions of the electronic document data is about 100 bytes. Thus, it will be appreciated that the image data portion (underlined portion of FIG. 3 ) of the image command practically represents the entire size of the electronic document data.
[0029] The code patterns used in the embodiment are ones that can store 64-Kbyte data on an A4 sheet.
[0030] FIG. 4 shows the detailed configuration of the image processing device 2 . It comprises an image developing portion 11 as image developing means adapted to be activated during printing of electronic document data; a code pattern creating portion 12 as code pattern creating portion for encoding the electronic document data; electronic document data reducing portion 13 as data reducing portion for reducing the size of the electronic document data; a printing engine 14 as printing means for printing electronic document data and code patterns by electrophotographic processing on a paper sheet; a scanner 15 as image scanner adapted to be activated when the electronic document data are created; an electronic document creating portion 16 as electronic document creating portion for creating electronic document data, a code pattern recognizing portion 17 as code pattern recognizing means for recognizing the code patterns; and an electronic document data supplementing portion 18 as electronic document data supplementing means for supplementing data that has been reduced during printing. And finally, a controller is provided in the image forming device 2 . The controller detects a status of this system and determines various actions in such a manner of the flowcharts shown in FIGS. 5 and 7 .
[0031] How the image processing device 2 prints electronic document data is described with reference to the flowchart of FIG. 5 . First, electronic document data 8 are developed into print images in the image developing portion 11 . Specifically, in the example of FIG. 3 , start of the page is recognized based on the page command; an image memory for developing print images corresponding to the sheet designated in the sheet command is retained; a font is selected based on the font command; character strings designated in the text command are drawn on the image memory retained; image data designated by the image command are developed in the image memory retained; and finally, the computer recognizes the completion of development of images based on the end command.
[0032] Then, the printing engine 14 prints images created in the image developing portion 11 on the sheet (S 2 ).
[0033] In the next step (S 3 ), the program compares the size of the electronic document data entered with a predetermined value (64 Kbytes in this embodiment) to check whether or not the code patterns corresponding to the electronic document data printed on the sheet can be entirely printed on the print area on the back of the sheet.
[0034] If the electronic document data size is 64 Kbytes or less, the corresponding code patterns are created in the code pattern creating portion 12 by encoding the electronic document data as it is (S 4 ) because the code patterns can be entirely printed on the print area. Then, the printing engine 14 prints the code pattern image thus created on the back of the sheet (S 5 ).
[0035] If the program determines that the size of the electronic document data exceeds 64 Kbytes in Step S 3 , the electronic document data reducing portion 13 reduces the size of the electronic document data to the predetermined value to create temporary electronic document data which can be entirely printed on the print area (S 6 ).
[0036] Specifically, in this embodiment, the reducing portion 13 deletes e.g. only the image data in the electronic document data to create temporary document data corresponding to the character data. In such a case, only the image data are deleted with the image command itself retained. That is, the position data (x, y, width and height) in the image command, which represent the position of the image data in the document data, are retained. In this embodiment, the size of the temporary document data is about 100 bytes, so that the code patterns corresponding to the temporary data can be printed in the print area. FIG. 6 shows such temporary electronic document data, which do not include image data.
[0037] The code pattern creating portion 12 encodes the thus created temporary electronic document data to create code pattern images (S 7 ). Finally, the print engine 14 prints the code pattern images on the back of the sheet (S 5 ).
[0038] The flowchart of FIG. 7 shows how the image processing device 2 creates electronic document image. First, the scanner 15 reads the code patterns 7 printed on the back of the paper sheet 4 (S 11 ), and transmits the data thus read to the electronic document image creating portion 16 . The latter then creates temporary electronic document data, that is, restore the original electronic document data by recognizing the code patterns read from the paper sheet 4 using the code pattern recognizing portion 12 .
[0039] The electronic document creating portion 16 then determines whether or not the image command in the restored temporary electronic document data contains image data (S 13 ). If there exist image data, which means that the electronic document data have been printed entirely with no image data deleted, the temporary electronic document data are regarded as the ultimate electronic document data 8 (S 14 ).
[0040] If the electronic document creating portion 16 determines in Step S 13 that there exist no image data, which means that the image data have been deleted, the electronic document data supplementing portion 18 acquires image data by scanning the front side of the paper sheet through the scanner 14 according to the position data (x, y, width and height) and parameters on the number of colors in the image command restored based on the code pattern read.
[0041] The image data thus acquired are incorporated into the temporary electronic document data to supplement the image data that have been deleted during printing, thereby creating the final electronic document data 8 (S 16 ).
[0042] The electronic document data 8 thus created (restored) can be repeatedly printed by inputting the data 8 into the image developing portion 11 without the possibility of deterioration of the image quality. The data 8 may also be stored in an image memory (such as a hard-disk device) (not shown) in the image processing device 2 for later used.
[0043] The code patterns may be printed on an empty space on the front side of the sheet instead of on the back thereof or on a separate sheet. Also, the code patterns may be printed with an invisible ink.
[0044] In the embodiment, when data are printed, image data are deleted to reduce the size of the electronic document data to be converted to code patterns, and the image data thus deleted are added by scanning the front side of the sheet based on the positional data of the image data in the code patterns read when the electronic document data are created.
[0045] But instead, the size of the electronic document data may be reduced in other ways, e.g. by reducing the resolution or the number of colors of the image data to be converted to code patterns or by downloading the image data from a server on a separate network.
[0046] The present invention thus makes it possible to restore electronic document containing image data such as color graphics and thus large in data size and to relax the upper limit of the size of the electronic, document data that can be printed on a sheet of paper.
[0047] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
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An image forming apparatus includes a creating portion for determining whether or not document data give have a capacity greater than a first predetermined value, and creating code patterns by encoding the document data as it is, if the controller determines that the document data have a capacity smaller than the first predetermined value, a creating portion for reducing the document data by a second predetermined value and creating code patterns by encoding the thus reduced document data, if the controller determines that the document data have a capacity greater than the first predetermined value, and an printing engine for forming the thus created code patterns and the document data on a sheet of paper. With this arrangement, it is possible to print even large-capacity document data on the back of the sheet of paper in the form of code patterns.
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This application incorporates by reference Taiwanese application Serial No. 90114487, filed Jun. 14, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a jet ink of magenta. More particularly, the invention relates to a jet ink of magenta with the properties of high light-fastness and high water-fastness.
2. Description of the Related Art
In a color ink-jet printer, the jet inks in the cartridges usually consist of cyan ink, magenta ink, and black ink. Recently, some jet inks of lighter color, such as light magenta, light cyan, and light yellow, are also used to make the printed material more colorful.
The colorants of the inks are mainly divided into the two groups of dye and pigment, wherein the former is more suitable for jet inks due to its property of being more hydrophilic to water. However, the dye's more hydrophilic property also results in a weaker water-fastness and a weaker light-fastness, which causes the color-fading phenomenon by photo-chemical reaction, such as photolysis, photo-synthesis, and photo-sensitization. Although the pigment has high water-fastness and light-fastness, it has poor property of color lightness, color hue, color chroma, and particle dispersing, which easily causes the pigment to condense, precipitate, and induce the clogging of the nozzle.
SUMMARY OF THE INVENTION
The object of the present invention therefore is to provide a jet ink of magenta comprising a reactive red 180, an acid red 52, and a reactive red, wherein the properties of light-fastness and water-fastness are improved greatly and thus, so is the printing quality. The contents of the reactive red 180, acid red 52, and reactive red all range from 0.1 wt % to 10 wt %.
The jet ink of magenta further comprises surfactant, humectant, buffer solution, dispersant, binder, chelating agent, biocide, UV-blocker and water, wherein the surfactant is selected from the group consisting of anionic type, nonionic type, cationic type, and amphoteric type, and its content is less than 20.0 wt %, preferably in the range from 0.1 wt % to 15.0 wt %. The content of humectant is less than 20.0 wt %, preferably in the range from 10 wt % to 20 wt %, and the humectant is a low volatile liquid, such as glycol, ethylene glycol and diethylene glycol. The content of water is about 50.0 wt % to 95.0 wt %.
The above objects and other advantages of the present invention will become more apparent from a detailed description of the preferred embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Colors can be indexed by a color appearance system and a color mixing system. The color appearance system, such as the Ostwald appearance system, Munsell appearance system, and German appearance system, arranges different colors formed on realistic objects. The Munsell appearance system, created by an American painter, defines colors by the three properties of hue, value, and chroma.
The color mixing system generalizes different colors formed by the three primary colors of light, wherein the Commission Internationale de L'Eclairage (CIE) system for measuring colors is the most important system and is used in the present invention. In the CIE system, the color gamut is defined by L*, a*, and b*, which represent the lightness, hue, and chroma of a color, respectively. The hue of a color represented by a* ranges from green of −a to red of +a, and the chroma of a color symbolized by b* ranges from blue of −b to yellow of +b.
Particularly, in the more specific CIELAB system, the square of the color difference represented by (ΔE)2 is the sum of (ΔL*)2, (Δa*)2, and (Δb*)2, wherein ΔL*, Δa*, and Δb* are the lightness difference, hue difference, and chroma difference of color, respectively. Therefore, the greater ΔE indicates a greater difference between the colors.
In the present invention, the jet ink of magenta comprises a reactive red 180, acid red 52, reactive red, surfactant, organic solvent, and water, wherein the contents of the reactive red 180, acid red 52, and reactive red range from 0.1 wt % to 10 wt %. The surfactant is selected from the group consisting of anionic type, nonionic type, cationic type, and amphoteric type, and its content is less than 20.0 wt %, preferably in the range from 0.1 wt % to 15.0 wt %. By adding the surfactant, the surface tension, the humectant property, and the dispersion characteristic are improved, such that the phenomenon of a clogged nozzle is prevented.
The jet ink of magenta further comprises a humectant, UV-blocker, chelating agent, buffer solution, dispersant, binder, biocide, preservative, and so forth, wherein the content of humectant is less than 20.0 wt %, preferably in the range from 10 wt % to 20 wt %. The humectant can prevent the clogging of the nozzle by reducing vaporization, and is a low volatile liquid, such as glycol, ethylene glycol, and diethylene glycol. The content of water is about 50.0 wt % to 95.0 wt %.
Preferred Embodiment
The constituents and the corresponding contents in a jet ink of magenta are shown in Table 1 according to a preferred embodiment of the present invention.
TABLE 1
Constituent
Content (wt %)
Reactive red 180
3.0
Acid red 52
0.5
Reactive red
0.5
Surfactant
5.0
solvent
5.0
others
5.0
Water
50.0 ˜ 85.0
The comparison experiments corresponding to the above preferred embodiment are the jet inks of magenta in the current market, for instance, the magenta cartridge C6578 of HP Corp., the magenta cartridge 1980 of Lexmark Corp., and the magenta cartridge 193 of Epson Corp. The four magenta cartridges including the preferred embodiment described above are respectively supplied to the general jet printer to test the light-fastness property and the water-fastness property.
For the light-fastness test, every magenta cartridge is printed in an ink-jet printing paper (for instance, a Mitsubishi coated paper), on which the effect of light fastness is more easily intensified than general paper. The printed Mitsubishi coated paper is first measured for its properties of color by a spectrophotometer, and then irradiated for 16 hours by a simple emitting machine of Microsol, wherein the irradiation quantity is equivalent to exposing to sunlight for 10 hours per day in three and half months. Next, the irradiated Mitsubishi coated paper is again measured for its properties of color by the spectrometer to obtain the color difference ΔE, as listed in Table 2, wherein the symbols of ⊚, ◯, and X correspond to the ΔE ranges of smaller than 3.0, 3.0 to 5.0, and larger than 6.0, respectively. The smaller color difference ΔE indicates the lesser color-fading phenomenon and the better light-fastness property.
TABLE 2
Experiment
ΔE
Jet ink of magenta from the present invention
⊚
Jet ink of magenta C6578 from HP Corp.
X
Jet ink of magenta 1980 from Lexmark Corp.
◯
Jet ink of magenta 193 from Epson Corp.
◯
For the water-fastness test, the entire paper provided with jet ink of magenta is first measured for its properties of color by the spectrophotometer. Next, the entire paper is dipped in deionized water for a half-hour and is dried naturally at room temperature. Then, the dried paper is again measured for its properties of color by the spectrometer to obtain the color difference ΔE, as listed in Table 3, wherein the symbols of ◯, Δ, and X represent the ΔE ranges of 40-50, 50-70, and larger than 70 Irespectively. The smaller color difference ΔE indicates the lesser color-fading phenomenon and the better water-fastness property.
TABLE 3
Experiment
ΔE
Jet ink of magenta from the present invention
◯
Jet ink of magenta C6578 from HP Corp.
Δ
Jet ink of magenta 1980 from Lexmark Corp.
X
Jet ink of magenta 193 from Epson Corp.
Δ
From the results in Table 2 and Table 3, the jet ink of the present invention has the advantage of reducing the color-fading phenomenon as tested by dipping in water and irradiating with light. Therefore, by combining the reactive red 180, acid red 52, and reactive red, the properties of light-fastness and water-fastness are improved greatly, and thus, so is the printing quality.
Once given the above disclosure, many other features, modifications, and improvements will become apparent to the skilled artisan. Such other features, modifications, and improvements are considered to be a part of this invention, and therefore the scope of the following claims should be accorded the broadest interpretation.
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A jet ink of magenta comprising reactive red 180, acid red 52, and reactive red is disclosed in the present invention, wherein the said jet ink of magenta has the advantages of decreasing the color-fading phenomenon due to water exposure and light irradiation. Therefore, the properties of light-fastness and water-fastness are improved greatly, and thus, so is the printing quality.
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FIELD OF THE INVENTION
This invention relates to devices for protecting single and multiphase high voltage apparatus to provide overvoltage protection and apparatus test, and more particularly relates to the means for testing single and multiphase high voltage apparatus equipped with surge arresters or surge protectors and/or test the surge arrester without the necessity of disassembling the apparatus. Even more specifically, this invention relates to an oil filled apparatus such as a transformer having a surge arrester of the metal oxide varistor (MOV) type designed for under oil mounting and an external isolator.
BACKGROUND
Very often, it is necessary to test for any one of a number of reasons both in the field and prior to being shipped the single phase and multiphase voltage apparatus, i.e., transformer and/or its surge arrester. For example, after a transformer is subjected to high voltage transients, which could damage or destroy it, it may be necessary to conduct tests in order to determine whether a part should be replaced. During manufacture there could be faulty connections or the like. Therefore, it may be necessary to test the transformer after manufacture and before shipment. It may also be desirable, and often necessary to conduct routine tests on the transformer in order to determine that it is in good working order.
Oil filled transformers and metal oxide varistor arresters are known. Generally, it is necessary to provide an arrester or a surge protector which protects the transformer against high voltage transients. For this reason, it is common practice to connect an arrester which will conduct transients from a power line to ground ahead of or at the transformer when high voltage occurs. The surge arrester may be mounted within the transformer tank.
High voltage surges actuate the arrester so that damaging electrical potentials are shunted to ground via the arrester before the transformer can be destroyed. Since the internally mounted arrester provides a path for shunting high voltage to ground, it also prevents a valid dielectric test of the transformer insulation system. Thus, it is not possible to test the transformer without disconnecting the internal arrester.
Therefore, the common practice is to disconnect the arrester, dielectrically test the transformer, and then reconnect the arrester or surge protector. In the case of an oil filled transformer which has an arrester mounted therein, it is both awkward and costly to test the transformer and/or arrester. The transformer tank must be opened to so disconnect and reconnect the surge protector. This therefore substantially eliminates field and/or installation evaluation of the transformer.
Still another condition which leads to cost problems and design restrictions is the need heretofore wherein an arrester failure should result in an open circuit fault. For example, most arresters are designed to melt open an isolating fuse link or to fracture and result in an open circuit condition when a transient persists for a period of time. Thereafter, it is necessary to disassemble the transformer and clean and remove all of the arrester parts from the transformer housing. This is especially difficult when the transformer housing is filled with oil. Further, when an under oil arrester mounted in an oil filled transformer fails there is no readily visible means to indicate the arrester failure.
SUMMARY OF THE INVENTION
According to the present invention, we provide a new and improved means for testing a single or multiphase high voltage apparatus having an arrester mounted therein without having to either open its housing or partially disassemble it.
Accordingly, an object of the invention is to provide oil filled high voltage apparatus with arresters or surge protectors which do not have to be disconnected in order to test the transformer either in the factory after manufacture and before shipment or in the field during operation. A further object is to provide the means for remotely separating or isolating the apparatus from the surge protector.
Another object of the invention is to provide a visual indication of the destruction of a surge arrester mounted within a transformer housing so that workers in the field can quickly tell if a transformer must be tested and repaired or replaced.
Yet another object of the invention is to provide means whereby an internally mounted arrester no longer has to fail in an open circuit condition. Here, an object is to enable a an arrester to fail in a short circuit mode and still to give ample "open circuit" isolation.
An oil filled transformer has suitably mounted in its transformer housing a surge arrester of the metal oxide varistor type. An isolator is externally mounted on the transformer housing and has an external visible link thereon. The visible ground wire connected to the isolator is connected to a ground point outside the housing. The other end of the isolator is connected to the arrester inside the housing. Thus, the arrester is connected from a ground point outside the transformer housing through the isolator. High voltage transients are conducted to ground via the arrester. As stated above, the arrester may be activated or destroyed by high voltage and high current transients. When the energy level of the transient is sufficient to damage the arrester it will also be sufficient to blow-off the visible ground lead and disconnect the external ground connection. Thus a man in the field can readily see when the arrester internally mounted in a transformer tank has been damaged.
Further, the externally mounted isolator enables the transformer to be readily tested. To test the transformer of the present invention, the ground connection outside the transformer is disconnected from the isolator. This leaves the arrester in an open circuit condition so that the transformer may be tested via its external wires without interference from the arrester. If required, an insulating cap can be placed over the isolator to provide greater insulation to ground during the dielectric tests.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in the attached drawings, wherein:
FIG. 1 schematically illustrates a two coil transformer in an oil filled housing with an under oil arrester in a vertical position between transformer coils;
FIG. 2 is a cross-section taken along line 2--2 of FIG. 1;
FIG. 3 is a cross-section which shows a wall or cover mounted feed-through bushing insulator and arrester disconnector;
FIG. 4 is a schematic illustration of a single coil transformer having a horizontal surge arrester;
FIG. 5 is a cross-section taken along line 5--5 of FIG. 4; and
FIG. 6 is a graph showing a typical arrester isolator disconnect characteristics that are used by the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show a transformer housing 20 coupled to a high voltage line 22 via a primary insulated bushing 24. The housing is substantially full of oil, up to level 26 or other insulating media. Oil is commonly used within the housing to provide the required dielectric strength.
Inside the housing, an oil insulated transformer is provided in any conventional design. We illustrate here two coils 28, on a core 29 in a conventional manner. The exact design of the transformer is not relevant to our invention.
The transformer has a primary wire 22 connected to an insulated bushing 24 on the exterior of tank 20. The external connections 22 and point G are available for conducting specified dielectric tests.
Enclosed within tank 20 is any suitable and known arrester or surge protector 30 which is designed to protect the transformer from high voltage. The preferred arrester is a metal oxide varistor type which provides a non-linear resistance that decreases under over voltage conditions. If the voltage transient is high enough, the resistance of arrester 30 significantly decreases, limiting the over voltage applied to the potential point P1, thereby protecting the transformer winding 28.
The arrester 30 is preferably positioned within the tank 20 in a position which minimizes the length of the lead lines 31, while placing the arrester in a mechanically safe and fully protected position. The short lead lines are desirable primarily to prevent their impedance from increasing the overvoltage stress on the winding 28.
The arrester 30 is grounded at point G, via a through the wall external insulator/isolator 32 and connected, to a high potential point P1. High potential point P1 is between primary bushing 24 and transformer coil 28.
Under normal operating conditions, the arrester resistance is high and has no significant effect upon the potential at point P1. However, if lightning, for example, should strike the primary feed line 22, the resulting high voltage transient significantly reduces the resistance of arrester 30 in order to conduct the transient to ground and remove the current surge that might damage the coil 28. Upon cessation of the overvoltage, a sharp increase in resistance of the arrester takes place and the current through the arrester 30 returns to the magnitude typical for normal service.
Referring to FIG. 3, the external wall or cover mounted arrester insulator/isolator 32 is shown in a partial cross sectional view as mounted on the transformer tank 20. The insulator/isolator 32 may have any appropriate configuration. We use an insulator/isolator 32 having a feed-thru bushing insulator 40 with an appropriate isolator 51 mounted thereon. The isolator has an appropriate disconnector 52 releasably mounted thereon. The insulator bushing 40 is made of any appropriate insulating material. The insulating material and insulating characteristics of the insulator bushing are such that, with the ground lead removed from the isolator, standard dielectric high potential tests may be run on the transformer. In some cases it may be desirable to encase the external isolator 51 with an insulating cap (not shown) to provide additional voltage withstand capability.
In general, there is a hole in the wall or cover of the transformer tank 20 through which the insulator bushing 40 may pass. Threads T are formed on the inside end of insulator bushing 40. A compression gasket 42 is trapped between insulator 40 and tank 20 on one side and a compression nut 44 is threaded onto the threaded end of insulator 40 on the inside of the tank 20. When compression nut 44 is tightened, the gasket 42 forms an oil tight seal between tank 20 and insulator 40. The oil seal is necessary to prevent oil leakage or moisture ingress.
Extending through insulator 40 is a threaded stud 46 which has a threaded receiver hole 49. The isolator 51 has a threaded terminal 50 that is screwed into the hole 49. An advantage of this construction is that the isolator 51 and/or disconnector 52 may be replaced without having to either open tank 20 or break the oil seal at gasket 42. The arrester 30 is connected to stud 46 via wire 31 (FIG. 1). A ground wire 56 is connected from ground point G to a stud 58 (FIG. 3) on the arrester disconnector.
The disconnector 52 may be operated by a blank 22-cal. cartridge or other means such that the frangible housing of disconnector 52 is broken and the lead connected to 58 is disconnected from the arrester. The disconnector 52 is actuated when enough heat is generated to ignite the powder (not shown) in the disconnector 52. The heat occurs responsive to the high current conducted by the arrester during or after conditions such as voltage transients.
Although we have described the use of a power charge disconnector, any suitable thermal type release disconnector may be used.
In order to test the transformer without involving the arrester and surge protector 30, the ground wire 56 (FIG. 1) is disconnected from the lug 58, thereby removing ground from the arrester, which open circuits the arrester 30. The test may then be carried out by simply measuring the electrical characteristics on the transformer wire emerging from the housing 20 and point G. An insulating cap can be placed over the insulator/isolator so that the open circuited arrester 30 has no effect upon the testing. After the test is completed, ground wire 56 is reconnected to the lug 58.
Another embodiment is shown in (FIGS. 4, 5) where the insulator/isolator 32 is mounted in the tank wall instead of in the cover. Here, the same reference numerals are used to identify the same parts that are shown in FIGS. 1, 2. Therefore, they will not be described a second time.
For this type of transformer, the arrester 30 is shown mounted horizontally on insulated brackets 62, 64 which are secured to the transformer core/coil assembly 29a.
Heretofore, arresters were usually designed to fail in an open circuit mode. This requirement caused arresters to be designed to fall apart or otherwise destroy themselves in order to be certain that there is a physical gap in the circuit after a failure has occurred. As a result, after a failure, the broken parts of the perished arrester remained in the transformer tank.
According to the invention, when a disconnector 52 (FIG. 3) operates, the frangible section ruptures and the ground wire 56 is blown off along with the arrester ground stud 58, thereby producing an open circuit between potential point P1 and ground G. This means that the arrester may not be either a short or an open circuit. Therefore, it is more probable that the arrester may not fall apart. Thus the whole arrester may be removed and the transformer placed back in service after replacing the arrester, and changing the oil.
FIG. 6 illustrates the desired disconnecting fault current-time characteristic for a disconnector 52. Some high voltage conditions (such as lightning strokes) do not last long enough to generate a current which is heavy enough to destroy the arrester 30. Therefore, it would not be either necessary or desirable to actuate the disconnector 52. On the other hand, if the energy level is high enough, it might be desirable to have an instantaneous disconnect.
The horizontal axis of FIG. 6 indicates the root mean square amperage of the fault current. The vertical axis indicates the time required to ignite an explosive charge after the indicated amperage occurs. The operating range or band 70 indicates the allowable variance V for disconnector operation.
The advantages of the invention should now be clear. It is possible to conduct testing upon the transformer after manufacture and before shipment without having to either open the cover or disconnect the arrester. In the event of arrester failure, blowing off the ground wire 56 gives a visual indication to a lineman so that he will know that maintenance is required, and to take the proper safety precautions. The failure of an arrester no longer must be an open circuit failure; therefore, it may not be necessary to design an arrester to have an internal disconnecting feature.
For convenience of description, this specification referred to "oil filled transformers". However, it should be understood that the principles of our invention may also be applied to many other types of transformers or other high voltage devices with other insulating systems which may require similar protection and testing. Therefore, the invention is to be construed broadly enough to cover all equivalent structures including both single and three phase devices.
Those who are skilled in the art will readily perceive how to modify the invention. Therefore, the appended claims are to be construed to cover all equivalent structures which fall within the true scope and spirit of the invention.
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An arrester for an under oil transformer is connected between a primary bushing lead and an insulator/isolator penetrating the wall of a housing which encloses the oil, arrester, and transformer parts. A ground wire outside the housing is removably connected to the isolator which functions as a circuit disconnector. The ground wire is removed to open circuit the arrester so that the transformer may be tested without having to disable any parts in the housing. Responsive to an arrester failure, the ground wire is blown away to give a visual indication of the failure. The blowing away of the ground wire eliminates the need for the arrester to fail in an open circuit condition.
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This application is a division of application Ser. No. 274,969, filed June 18, 1981, now U.S. Pat. No. 4,359,546.
BACKGROUND OF THE INVENTION
This invention relates to mats for asphalt underlay as a base for asphaltic road surfaces.
In one of its more specific aspects, this invention pertains to a composition mat and binder suitable for use as an underlay for asphalt paving for road surfaces.
The use of non-woven mats as an underlay for asphalt paving is well known. Generally, such mats are employed by first applying to the highway to be repaired an asphalt composition over which the mat is laid and to which the mat adheres. A tack coat may, or may not, be applied over the mat. In either instance, an asphalt mix is then deposited over the mat and the surface is leveled and rolled. One of the mats presently so employed is comprised of non-woven, needle-punched polypropylene.
The most important property such mats much possess is tensile strength. In addition, such mats should possess low porosity to prevent excess asphalt for strike-through, should exhibit high flexibility and elongation and should not cause skin irritation to those handling the mats.
STATEMENT OF THE INVENTION
There has now been developed a mat which possesses such properties. This mat comprises a woven or non-woven composite having on its surface a residue formed by removing water from an aqueous composition comprising a thermoplastic emulsion and a melamine formaldehyde resin.
In a preferred embodiment, the thermoplastic emulsion will be selected from the group consisting of carboxylated styrene-butadiene latexes, vinyl chloride-ethylene acrylamide terpolymers, styrene acrylics and vinyl acrylics, or mixtures thereof, a carboxylated styrene-butadiene polymer in combination with an ethylene-vinyl chloride-acrylamide being the most preferred combination of thermoplastics.
The mat of this invention has been found to be highly satisfactory in the laying of composition road surfaces in which the road paving composition is superimposed on the mat.
DESCRIPTION OF THE INVENTION
If an acrylic polymer is employed, it will preferably be in the form of an aqueous acrylic emulsion such as E-1653, available from Rohm and Haas, Philadelphia, PA. This material is about 47.5 weight percent solids, is contained in an anionic surfactant system and has a 13° C. film forming temperature.
If a carboxylated styrene-butadiene latex is employed, it will preferably be in the form of an aqueous emulsion such as Dow Latex 485, available from Dow Chemical Co., Midland, MI. This material is 46 weight percent solids and has a film forming temperature of about 25° C.
If an ethylene vinyl chloride is used, it will preferably be in the form of an aqueous emulsion of vinyl chloride-ethylene-acrylamide terpolymer such as Airflex 4514, available from Air Products and Chemicals, Inc., Philadelphia, PA. This material is 48 weight percent solids.
Any suitable melamine-formaldehyde resin can be employed. One particularly suitable melamine-formaldehyde resin is Diaron 27-611, available from Reichhold Chemicals Inc., White Plains, NY. This material is a methylated melamine formaldehyde provided as a water soluble composite containing 60 weight percent solids.
Another suitable melamine-formaldehyde resin is Cymel 303, available from American Cyanamid, Bound Brook, NJ. This material is hexamethoxymethylmelamine having a specific gravity (25° C.) of 1.2, a refractive index of 1.515-1.520 and a viscosity (Gardner-Holdt, 25° C.) of X-Z 2 .
The binder formulation will comprise, on a parts by weight-solids basis, from about 91 to about 97 weight percent aqueous thermoplastic emulsion, from about 3 to about 7 weight percent of the melamine formaldehyde resin and up to about 2 weight percent of a water-soluble ammonium salt catalyst, such as ammonium sulfate. It can also contain minor amounts of ammonium hydroxide as a pH modifier, and defoamers commonly used in the art.
In the preferred embodiment of the invention, the binder will be comprised of about 94 weight percent of the thermoplastic emulsion, about 5 weight percent of the melamine formaldehyde resin and about 1 weight percent of the catalyst.
In the preferred embodiment of the invention in terms of commercially available materials, the binder will be comprised of carboxylated styrene-butadiene latex (Dow's Latex 485) in an amount of from about 36.4 to about 58.2 weight percent, an ethylene-vinyl chloride-acrylamide (Air Products Airflex 4514) in an amount of from about 36.4 to about 58.2 weight percent, a methylated melamine formaldehyde (Reichhold's Diaron 27-611) in an amount of from about 3 to about 7 weight percent and up to about 2 weight percent ammonium sulfate as catalyst.
The binder of this invention can be applied to any mat of any material, however formed. For example, it can be applied to sized glass fibers, mineral fibers, synthetic fibers or natural fibers, or mixtures thereof.
For the preferred underlay mat of this invention, it will be applied to a mixture of glass fibers and synthetic polymeric fibers, such as polyester fibers.
Any suitable size and quantity of glass fibers will be employed.
Preferably, the sized glass fibers will be 6.4 to 15.7 microns in diameter, 6.35-50.8 mm in length and will comprise about 60 to about 100 weight percent of the fibers of the mat.
The polyester fibers will be 6 to 15 denier, about 25 mm to about 40 mm in length and will comprise up to about 40 weight percent of the fibers of the mat.
In the preferred embodiment, the glass fibers will be 19.05 mm long by about 10.9 microns and will comprise about 60 to about 80 weight percent of the mat. The polyester fibers will be 11/2 inches long, 15 denier and will comprise about 20 to about 40 weight percent of the fibers of the mat.
The mats of this invention can be made in any manner. However, they are preferably made by dispersing a well-mixed quantity of the selected fibers in an aqueous medium containing a dispersant such as a polyalkoxylated alkylamine wetting agent and withdrawing the fibers as a wet-laid mat from the aqueous medium. The entire process is well known in the art.
The binder of this invention can be applied to the dry mat in any suitable manner, all of which methods are known in the art. For example, the binder can be sprayed on or, preferably, the binder can be poured over the mat and the excess binder removed under vacuum. In the final cured mat, the binder will comprise about 20 to about 35 weight percent of the mat, preferably about 30 weight percent.
The binder on the mat can be cured in any suitable manner. Preferably, it will be passed through an oven at a temperature of about 500° to about 650° F. for a time sufficient to cross-link the components of the binder and to produce a non-tacky mat.
The following example sets forth the procedure for producing a preferred binder composition of this invention.
EXAMPLE I
One thousand pounds of water were added to a mix tank and with slow agitation, 2983 pounds of carboxylated styrene-butadiene rubber latex and 2567 pounds of ethylene-vinyl chloride-acrylamide were sequentially introduced thereinto.
One hundred pounds of a water diluted anti-foam agent were introduced into the tank and the composite was stirred for 16 hours. Thereafter, 230 pounds of methylated melamine formaldehyde were introduced into the main mix tank, followed by 1000 pounds of water.
While continuing to stir, sufficient ammonium hydroxide was added to adjust the pH to 6.5±0.2. and 267.4 pounds of 10 weight percent ammonium sulfate were sequentially added to the mix tank. 99.1 pounds of the antifoam agent were then added to the mix tank and sufficient water was added to the main mix tank to bring the total weight of the aqueous binder to 9000 pounds. Mixing was continued for a time sufficient to attain uniformity.
The aqueous binder had a pH of 6.6, a solids content of 32 weight percent and a viscosity of 8.5 cps 96° F.
It will be evident from the foregoing that various modifications can be made to this invention. Such, however, are within the scope of the invention.
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A woven or non-woven mat comprising natural or synthetic fibers bonded together with the residue formed by removing water from an aqueous composition comprising a thermoplastic emulsion and a melamine formaldehyde resin forms an underlay for asphalt paving for road surfaces.
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BACKGROUND OF THE INVENTION
This invention relates to dampening the vibrations associated with the use of wire rope in industrial applications. More particularly, this invention relates to apparatus for reducing both fatigue and corrosion of wire rope terminations.
The term wire rope is generally understood to comprise a symmetrically arranged and helically twisted assembly of strands. A strand, in turn, is a symmetrically arranged and helically twisted assembly of individual wires. For simplicity, the term wire rope as used herein will include strand, as well.
Wire rope is designed and constructed to transmit forces longitudinally along its axis. It must be able to withstand destructive forces, such as tensile loading, bending fatigue, lateral crushing, abrasive wear, and corrosion, which act upon it during service. This invention is primarily concerned with bending fatigue and corrosion.
While wire rope is recognized in industry as a widely applicable structural member possessing high-strength and flexibility, it is also recognized that it is only as strong as its weakest link. this weakest link is often the area in the vicinity of the fittings. Fittings, or terminations as they are known in the art, are accessories used as attachments for wire rope. The stresses and strains to which wire rope is subjected are generally concentrated at such fittings.
Devices such as flared metal dampener clamps, have been used in an attempt to decrease the vibrations and thereby reduce the fatigue stresses in the wire rope at the terminations. However, such clamps do little more than transfer the fatigue point from one point in the termination to another equally vulnerable point, with little improvement in fatigue resistance.
Corrosion, another of the destructive forces, can occur as a result of the exposure of wire rope to moisture, acids, alkali, and the like, [either in the atmosphere or in hydrospace]. In oceanographic applications, wire rope is particularly susceptible to destruction by corrosion. In fact, experience has shown that because of the environment of the ocean, the effect of corrosion and fatigue operating together is greater than the effect of the sum of the effect of each. Prior art dampener clamps, have been found to be essentially ineffective in preventing either corrosion or fatigue in hydrospace.
SUMMARY OF THE INVENTION
According to the present invention a boot for wire rope terminations is fabricated of an insulative or non-conductive material and provided with seals for the wire rope-termination interface, the boot-termination interface, and the wire rope-boot interface. Through the use of this boot a positive attachment of the boot to the termination is made possible. It is lightweight, is simple to use, provides a complete seal for the termination, may be removed and reinstalled for inspection purposes, and may be adapted to many types of fittings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-sectional view of a wire rope termination of the hot metal type with a boot constructed in accordance with a first embodiment of the present invention.
FIG. 2 is also a longitudinal cross-sectional view of a wire rope termination of the hot metal type but with a boot constructed in accordance with a second embodiment of the present invention.
FIGS. 3a and b are an elevation view and an end view, respectively, of a boot according to a third embodiment of the present invention installed on a bridge-type wire rope termination.
DETAILED DESCRIPTION OF THE INVENTION
In the embodiment of the invention depicted in FIG. 1, a zinc socket termination 10 with a boot 11 made in accordance with this invention is shown installed on the end section of a wire rope 12. The termination 10 comprises a bail (not shown) and a socket 14. The bail is an open or closed "U-shaped" member which provides the attachment means for the wire rope. As shown, socket 14 may be provided with a conical opening into which a wire rope end section is inserted and secured to the socket. Any of the conventional methods for effecting such securing may be utilized. For example, molten metal such as zinc may be poured into the opening and solidified, a wedge-type socket may be utilized or the shank of the fitting may be cold-formed or swaged to the wire rope. However, irrespective of the manner in which the rope and section is secured, in this embodiment of the invention the socket nose 15 is connected to the boot by means mated thread portions. FIG. 2 illustrative of an alternative means for connecting the boot to the termination, wherein the flange portion of the boot is firmly bolted to the front face of the termination.
The installation of the boot 11 is begun before the termination 10 is attached to the wire rope 12. Prior to the insertion of the end section of the wire rope into the termination, a tube 16 of heat shrinkable plastic is passed over the end section a sufficient distance from the end to allow room for the other elements to be placed on the rope. Next, the wire rope is inserted into the leading end 17 of the boot 11. The boot comprises a tubular portion 18 and a flange portion 19 at the trailing end thereof. The tubular portion has an inner diameter designed to provide a tight fit around the circumferential surface of the wire rope. Its effective outer diameter is designed to be smaller than the inner diameter of the heat shrinkable tube so that the tube may be slipped over the tube-like portion of the boot. Although the tube-like portion of the boot shown in the figures to have a circular cross-section, it will be readily apparent that its outer surface need not be circular. For example, the outer surface may be elliptical, rectangular, hexagonal, etc. Whatever the shape of the tube-like outer surface, it is required that the largest diametrical distance (eg. the diagonal, if a square outer surface is employed) or the effective outer diameter be smaller than the inner diameter of the heat-shrinkable plastic tube. The flange 19 is integral with and surrounding the outer surface of the trailing end of the tube-like portion 18. In the FIG. 1 embodiment of the invention, the flange 19 is integral with cap 20, having internal threads therein which mate with the external threads 21 on the socket nose. In the FIG. 2 embodiment, the flange 19 has been drilled to receive bolts 22 for securing it to the socket nose. This embodiment is particularly useful in connection with terminations which generally have a limited amount of space available for installing a boot, eg. such as bridge terminations. A bridge termination is shown in an elevation view in FIG. 3a and an end view in FIG. 3b. In this embodiment the flange 19 has a configuration which allows the boot to be attached to the socket nose 15 between the adjusting bolts and nuts 23.
After the end section is secured, the flange 19 is connected to the socket nose to make a fluid-tight seal between the socket nose 15 and the flange 19. Referring to FIG. 1, teflon tape may be placed on the external threads 21 of the socket nose to help provide the proper seal. Other common gasket materials may be used in similar manner to enhance sealing. The heat shrinkable tube 16 is then placed over the tube-like portion 18 of the boot. The tube 16 should be of sufficient length to partially cover the tube-like portion 18 so as to extend over the leading end 17 of the boot and to cover the wire rope, as well. Finally, the tube 16 is heated to shrink it into sealing position on the wire rope and the leading end of the boot, so as to provide a fluid-tight seal.
While the boot 11 may be constructed so that the junction of the wire rope 12 and the zinc slip 23 may be sealed merely by the connection of the boot to the socket, it may be advantageous to provide for enhanced sealing of the junction, eg. by placing mastic or other sealing material at this junction before the boot is secured to the socket nose. Thus, when the boot is secured, the pressure of the boot against the socket nose causes the mastic to spread out and fill even the slightest imperfection in the fit and insure a positive seal. Similarly, mastic may also be placed around the wire rope at the lead-end of the boot 17 to insure a positive seal at the boot-wire rope interface. In oceanographic applications or other applications where extremely high fluid pressures are encountered, it will be advantageous to substitute hot welds or O-rings for the mastic at the zinc slip and at the boot head.
The figures also illustrate the use of the boot in connection with a wire rope having an extruded plastic jacket 30, a portion of which has been cut away to allow the rope to be splayed. After the rope is secured in the termination, the bare portions of the wire rope may again be jacketed by placing mastic in the gap 24 between the zinc slip 23 and the cut away end of the jacket 30. Polyvinylchloride tape 25 or the like may then be wrapped around the gap to retain the mastic.
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A lightweight, easily-installed boot for wire rope terminations is water-tight and adaptable to a variety of wire rope terminations. The boot is placed on the surface of a wire rope and secured to the socket nose of the termination to seal the termination-wire rope interface; then, a polyolefin heat shrinkable tube is placed over the head of the boot to seal the wire rope-boot interface.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to a fluid dispensing system with a device for controlling the flow of fluids through a plurality of valves, and more particularly to a shaft-mounted cam that through a combination of translational and rotational motion can sequentially open or close one or more valves to precisely control the ratio of fluids added to a fluid mixture.
[0002] The use of valves and valve actuators to control the flow of gases and liquids in a fluid combining process or system is well known in the art. One area where precise actuation and control of the valves is critical is in chemical processes, where a large number of valves are employed, often in an extensive array of piping, conduit, ducting or related fluid carrying and containing equipment. The attendant level of monitoring and process control necessary to ensure that these larger, more complex valving systems are performing their intended tasks has rendered manual control of such systems difficult. In response, automated valve control was developed, and with the advent of computer-controlled systems, even more sophisticated ways to control and monitor any given chemical process have become commonplace. While the more precise, predictable control over valve closure and opening associated with automated devices has enabled improved system functionality, it has come with system cost, weight and complexity burdens.
[0003] Many of today's modem chemical processes, including oil or petroleum refining, food and drug manufacturing and electric generation, rely extensively on the complex interconnection of pumps, piping and valves to effect a particular chemical conversion or mixture. One of the more frequently used forms of chemical processing involves the use of a fluid dispensing system, wherein a single fluid transport conduit permits multiple fluids to be selectively injected into a main stream to create a final mixed product for dispensing. However, there are situations in which fluid dispensing systems, although potentially beneficial, have not found application. One example is the preparation of etchants for metals in the metallurgical laboratory. They are usually prepared in small quantities (typically 100 ml or less), and owing to their reactivity with metals are corrosive and hazardous by nature. Typically, these etchants are recipes comprising a mixture of constituents formulated to react with a given metal. As such, precise control over the ratios to ensure a quality etchant mixture is necessary. While such precise control with prior art systems embodying fluid dispensing features is possible, their reliance on multiple dedicated pumps or redundant valve and actuator engaging configurations results in complex, expensive systems that require that each actuator must be equipped with numerous dedicated devices in order to control multiple valves.
[0004] Another especially acute problem involves the precise control of minute quantities of fluids. When small quantities of injectants are being mixed, such as with medicament samples, acid etchants and related chemical reagents, the lack of a simplistic fluid dispensing system, which can meter precise amounts of the desired fluids reliably, affordably and safely is a hindrance to the creation of application-specific fluids. In response to ever-increasing demands that end product mixtures be of extremely high quality, with minimal contamination, waste and risk of exposure of personnel or the environment to hazardous substances, existing systems have added backup and redundant componentry, exacerbating system cost and complexity. Depending on the size of the fluid transport conduit in a fluid dispensing system, the driver fluid in the conduit's main stream could be either a conventional liquid (most notably water) carrier or an immiscible gas (most notably air) being drawn into the main stream through a supply valve. With a liquid-based driver system, a “pusher” fluid is used to move the injectant through the main stream of the conduit and into the dispensing unit. By using an “all liquid” approach (i.e.: liquid pusher and liquid injectant), the potential for an extremely accurate final mixture exists, due in part to the incompressibility of the liquids. However, the present inventors have discovered that the size of the conduit effects the mixing process. If the conduit is too large, the discrete volume of fluid in the conduit tended to collapse and mix with the pusher fluid. Likewise, if the size of the conduit is too small (as can be the case when small quantities of injectant are used), friction effects can dominate, resulting in slow dispensing speeds and higher power requirements.
[0005] In metallurgical laboratories, metallurgists and metallurgical technicians routinely prepare etchants, mixtures of acids, solvents, and salts, which are used to etch metallographic samples, thus revealing microstructure and other features. The preparation of etchants, as it is currently practiced in the metallurgical lab, entails: the transfer of acids and solvents from the bottles in which they are supplied to smaller containers to facilitate handling; the measurement of volumetric quantities of these acids and solvents using graduated cylinders; and the mixing of the same in a container along with mass quantities of salts, if required. The handling and measurement activities are time consuming and entail significant risk to both personnel and the environment. Alternatively, some laboratories transfer acids and solvents from the containers in which they were purchased into an individual dispenser for each reagent, or insert a bottle top dispenser into each bottle in which a reagent is purchased. After the etching operation is completed, the etchant must be neutralized prior to disposal. Many laboratories perform the pH neutralization procedure with sodium hydroxide pellets. Because sodium hydroxide is highly reactive in acid, as are related acid neutralizers, it must be added slowly to minimize foaming and spatter. Personnel performing this operation check the neutralization process frequently using litmus paper to determine the pH of the solution. This can be tedious, time-consuming, and potentially dangerous to personnel, adjacent laboratory equipment and the ambient environment. In addition, it is frequently the case that too much neutralizer is added, thus necessitating the addition of more acid in an ad hoc process to ensure that an acceptable pH (typically in the range of 6 to 8) is reached prior to disposal. Not only does the prolonged exposure due to this back-and-forth process present additional risks to personnel, equipment and the environment, but it generates additional quantities of waste product as well.
[0006] Other applications for a fluid dispensing system capable of handling acids and solvents exist outside of the metallurgical laboratory. One example is compositional analysis of metals in the chemical laboratory using a technique known as inductively coupled plasma. Prior to analysis, the metal to be analyzed must be placed in liquid solution. To accomplish this, chemists dissolve the metallic sample in mixtures of acids and solvents similar to etchants. In the chemical laboratory, the preparation, neutralization and disposal of these solutions of acids and solvents proceeds in much the same way as it does in the metallurgical laboratory. Similarly, in other contexts, examples of commercially available systems exist in which a peristaltic pump is devoted to each liquid to be dispensed. Such systems may be combined with valve manifolds to redirect liquids to a plurality of locations. Valves in such manifolds are generally activated individually using electromechanical devices such as solenoids. Other commercially available systems use multiple screw driven syringes or multiple syringe pumps to dispense a multiplicity of liquids. In any event, exposure to harsh chemicals can present safety and operability risks that typically require additional costs associated with redundant, protective system componentry.
[0007] Accordingly, there exists a need for a fluid dispensing system that can offer greater simplicity, improved safety to using personnel, improved conservation of constituent fluids, and greater speed of fluid mixture preparation.
SUMMARY OF THE INVENTION
[0008] This need is met by the present invention by providing a simple, reliable means for controlling the opening and closing of multiple fluid insertion valves arranged in a common valve manifold without having to rely on the use of complicated, redundant actuators. The current invention preferably employs a cam which can be translated by means of a lead screw across a linear array of valves and rotated to actuate a given valve when located in juxtaposition to that valve. By placing a single pump upstream of the valve manifold and a dispensing nozzle downstream, the multiplicity of pumps can be eliminated. The inventors of the present invention have further recognized that their approach increases throughput of the dispensed final product while avoiding the complexity and redundancy of larger, heavily-arrayed fluid transport conduit systems. One of the chief attributes to the system of the present invention is that by using a single cam on a single shaft as a valve actuator engaging member, thus resulting in a single translation member and a single rotation member, the device is inherently simple and compact. Further system simplicity is ensured by the use of one or more conventional motors to move the cam, such as a stepper motor, servomotor or rotary solenoid. Alternatively, the use of multiple pumps of different sizes could be employed to achieve high volumetric accuracy when small amounts of reagent are to be injected into large amounts of solution. In this case pumps with different capacities may be plumbed either in parallel or in series in such a way that the smaller pump provides greater accuracy during aspiration where as the larger pump provides greater capacity during aspiration and greater speed during dispensing.
[0009] In accordance with one embodiment of the present invention, a fluid dispensing system (also known as an injectant dispensing system) is disclosed. It includes at least one pump for metering precise quantities of fluid to be dispensed; one or more fluid injection lines for transporting a fluid to be dispensed, and one or more valves with valve actuators, each of the valves disposed in one of the fluid injection lines, wherein the fluid injection lines can be in fluid communication with fluid dispensing containers at one end, and with a fluid transport conduit at the other. The fluid transport conduit is also in fluid communication with the pump. Each of the valves can control the flow of a quantity of fluid through one of the fluid injection lines. At least one valve actuator engaging member is coupled to each of the valve actuators so that, based on a control signal, each actuator engaging member can force a respective actuator on the valve to open or close the valve in response to the control signal. Furthermore, a pusher fluid is selectively introduced into the fluid transport conduit to force the flow of a fluid to be dispensed through the fluid transport conduit. In the present context, a pusher fluid is one used as a carrier, such that it moves the injectant fluid through the fluid transport conduit and into the pump. The choice of a particular pusher fluid can effect the way many of the system elements are interconnected. Specifically, the size of the fluid transport conduit, pump size and type can be tailored to the dispensing of small quantities of fluids to minimize or prevent fluid intermixing and residual droplet formation. In addition, the present inventors discovered that if the pusher fluid is a liquid, an optional filter device can be disposed in the pusher fluid injection line to not only reduce contaminant presence but also provide damping for flow stability. A flow detection system is disposed adjacent the fluid injection lines, and includes at least one detector and a controller in electrical communication with the detector, valves and pump such that upon detection and comparison of a flow variation, the controller sends signals to at least one of the pump or valves to control the flow of fluid. This system is especially well-suited to the use of acids, solvents and acid neutralizers.
[0010] Optionally, to meet the need of ensuring that the highly accurate approach of using a liquid pusher with a small bore conduit could be replicated without the aforementioned speed and power drawbacks, the present invention further may include an immiscible gas as the pusher in small conduit lines (such lines being commonly associated with the use of acid reagents for etchant solutions). Thus, by using a gaseous pusher fluid for small mixture quantities, where an appropriate amount of conduit is placed between the pump and the fluid injection valves in the absence of a liquid pusher, the aspiration of the fluid could be accurately metered, resulting in precise mixtures to be dispensed. Advantages of this approach include the use of a smaller, more simplistic fluid transport conduit, as well as reducing the need to dilute or mix the fluid with a water-based main stream carrier. As another option, the fluid dispensing system can include a capping mechanism adapted to be disposed in the container apertures, thus acting as a stopper to prevent unintended release of fluids from the container. Furthermore, the capping mechanism permits the flow of fluid to and from the container under normal operating conditions by being operatively responsive to pressure differentials arising out of putting fluid into and taking fluid out of the container. The capping mechanism, which is operatively responsive to a pressure differential across the aperture in each of the containers, can include the following features: a generally cylindrical body; at least one threaded groove disposed on the body's outer surface such that a complementary threaded top can be fit thereon; at least one recess disposed in an outer surface of the body and axially distant from the threaded groove. The recess is adapted to receive an O-ring to facilitate better sealing as well as easier, safer removal. At least one aperture is disposed therein to receive a fluid injection line. The capping mechanism itself may include at least one elastic vent member with at least one slit and at least one channel disposed therein; and at least one membrane plate with at least one recess and at least one channel disposed therein, where the recess is in substantially axial alignment with the slit. Slits placed in the compliant members can respond to pressure differentials between the inside and outside of the container, which then permits the insertion and withdrawal of fluid. In the alternative, the capping mechanism may include: a plurality of passages; at least one venturi; a plurality of generally spherical stoppers disposed within a chamber in the body such that they are seatably responsive to a pressure differential in the fluid transfer line that extends between the container and the fluid transport conduit, such that, upon exposure to a pressure differential, the generally spherical stoppers change their seating arrangement against the aperture. Another desirable attribute of the present invention is its incorporation of fluid containment devices that permit relatively “handsfree” fluid dispensing system operation of handling acids, solvents and dispensing liquid neutralizer. For example, the inventors discovered that when the mixing process involves hazardous substances, such as acids and related etchants, exposure of the vapors and liquids to personnel and sensitive equipment could be minimized through the use of an appropriate capping mechanism. The features of the capping mechanism permit the uninhibited access of fluid to and from the fluid container while simultaneously minimizing the chance of liquid spillage or inadvertent venting of corrosive or noxious vapors. With the inclusion of features such as this, the present invention greatly increases the efficiency of dispensing and neutralization processes by integrating improved safety features into the dispensing system's inherently simple design. As another option, a filter is disposed in the fluid injection lines to provide fluid damping. Additional options to the flow detection system include specific detector features. For example, the detector can be either an ultrasonic or optical detector, where more specifically, in embodiments using the optical detector, it can be an IR detector. Another option is the inclusion of a neutralizer with integral dye indicator into the fluid dispensing system. The neutralizer comprises a base in liquid solution mixed with a dye indicator. Upon addition to an acidic solution, the pH changes. When the pH range of 6 to 8 is achieved, the solution undergoes an abrupt color change. One example of such a neutralizer is triethanolamine, although other solutions, including sodium hydroxide, can be used. Another option includes an enclosure to house one or more of the various components of the fluid dispensing system such that they are disposed within the enclosure. Preferably, the enclosure contains the pump and valve assembly, and is sized to conveniently fit in a fume hood, or on top of a table designed to house fluid reagents, thus providing a compact, autonomous container for the fluid dispensing system.
[0011] In accordance with another embodiment of the present invention, a cam assembly is disclosed. The apparatus comprises a shaft, a rotational member, a cam, and a cam driver. The shaft and rotational member each include an axis of rotation along their respective length. The cam moves in at least two degrees of freedom, where the first is preferably a translational movement operatively responsive to its threaded relationship with the turning shaft, and the second is preferably a rotational movement operatively responsive to the interaction between complementary mating cam and rotational member surfaces. Furthermore, each cam degree of freedom movement is independently responsive to shaft and rotational member motion, caused in turn by the cam driver coupled to the shaft and rotational members. In the present context, “independently responsive” means that even though the cam is coupled to both the shaft and the rotational member, it does not require the simultaneous movement of both to perform its intended function. To take up as little space as possible, that shaft can be disposed concentrically inside a hollow portion of the rotational member, and the cam can be disposed on an outer surface of the rotational member so that the axes of rotation of the shaft, cam and rotational member are coaxial. This space-saving feature is highly desirable in volume-limited applications, such as when working with hazardous substances, where the entire assembly might need to be located in a fume hood or similar device. Moreover, the cam driver need not be a single motor, but instead can comprise a first motor for imparting translational movement to the shaft, and a second motor for imparting rotational movement to the rotational member.
[0012] In accordance with another embodiment of the present invention, a flow control apparatus for porting fluids is disclosed. The apparatus comprises a housing and a plurality of valves, in addition to the cam assembly described in the previous embodiment. The housing supports the plurality of valves, as well as the shaft, cam and rotational member. Each one of the valves include a valve actuator, that, on one end, is connected to the valve such that movement of the actuator opens or closes the valve. The other end of the actuator engages the eccentric portion of the cam such that rotational changes in the cam produce changes in the actuator's position. In addition, a flow detection system with at least one ultrasonic or optical sensor may be included, and, in the case of an optical detector, operable in either the IR or visible band. This flow detection system can be integrated into a microprocessor-based controller to ensure accurate and repeatable quantities of mixing fluids are being drawn into the mixing region of the pump from their containers. As with the aforementioned fluid dispensing system, this apparatus is especially well-suited to the use of acids, solvents and acid neutralizers.
[0013] In accordance with yet another embodiment of the present invention, a fluid dispensing system is disclosed. The fluid dispensing system comprises, a pump, a fluid transport conduit, a valve assembly and a flow detection system, and a dispensing unit in fluid communication with the valve assembly to accept fluid from the fluid transport conduit. The fluid transport conduit provides a containment path through which the injectant fluids can be circulated. The flow detection system (similar to the previously described fluid dispensing system) is in fluid communication with the fluid transport conduit, as is the valve assembly. The valve assembly contains a plurality of valves, each of which includes a valve actuator. While the valves are designed to be either open or closed, they could optionally be coupled to a feedback-based controller to provide flow rate control. The valve assembly itself comprises a housing, shaft, rotational member, cam and cam driver similar to that of the previous embodiment. Optionally, the fluid dispensing system further comprises at least one container for supplying the injectant, where the container is in fluid communication with the valve assembly and fluid transport conduit. The aperture of the container may have a capping mechanism similar to that described in conjunction with the previous fluid dispensing system embodiment. As with the prior fluid dispensing system embodiment, an enclosure can be included to house one or more of the individual components within the fluid dispensing system. Additionally, the fluid dispensing system includes safety and convenience features, such as a dispensing unit including a dispensing nozzle to facilitate the introduction of fluid in the fluid transport conduit into a receiving container (such as a beaker), a mixing device (such as a magnetic stirrer) to improve mixing of dispensed fluid in the receiving container, a door disposed on the enclosure to prevent fluid spillage from escaping, an interlock that prevents the fluid dispensing system from operating until the door is closed, a drain disposed within the dispensing unit to collect any fluid spillage inside the dispensing unit, a pressure relief valve to protect the fluid transport conduit from becoming overpressurized, and a waste receptacle attached to the drain and pressure relief valve. Optionally, the fluid dispensing system can accommodate various pusher fluids in a fashion similar to that of the previous embodiment fluid dispensing system. Also as with the previous embodiment fluid dispensing system, a neutralizer with integral dye indicator can be added to facilitate efficient neutralization of the dispensed fluids, which can include, among others, acids, solvents and acid neutralizers.
[0014] In accordance with still another embodiment of the present invention, a method for controlling the amount of fluid flowing through at least one of a plurality of valves is disclosed. The method comprises the steps of placing at least one fluid container in operative communication with at least one valve, arranging a valve actuator to be in mechanical communication with the valve, mounting a cam to both a shaft and a rotational member such that the cam is operatively responsive to movements in the shaft and rotational members, placing a cam driver to provide translational and rotational movement to the cam through the shaft and rotational member, and controlling the opening or closing of the valve in response to a predetermined process condition. This last step is accomplished by receiving an input from a control mechanism, sending a control signal from the control mechanism to the cam driver, translating the cam until it is aligned with the valve actuator, then rotating the cam to force engagement between it and the valve actuator to open the valve until a desired amount of fluid is injected into the fluid transport conduit. Optionally, the method is accomplished with a device that has the shaft axis of rotation coaxial with the rotational member axis of rotation, and where the control mechanism comprises a microprocessor-based controller. The method may also include installing a flow detection system, whereby air pockets or bubbles injected into either the fluid transport conduit or the fluid injection lines can be sensed, then correlating the sensed value against a predetermined fluid volume to be dispensed, then calculating a flow adjustment signal to send to the cam driver to adjust the valve to remain open for an additional period to ensure adequate quantities of fluid are dispensed. Other features that may be incorporated include an aperture in the fluid container with a capping mechanism such that when the fluid is flowing neither to nor from the container, the capping mechanism prevents the fluid from escaping from the container, as well as to facilitate the flow to or from the container during such periods that fluid transport is necessary. Such capping mechanisms having already been described herein.
[0015] In accordance with still another embodiment of the present invention, a method for preparing metallurgical etchants is disclosed. The steps of this method include: placing at least one fluid container with a fluid to be dispensed disposed therein in operative communication with at least one valve; arranging a valve actuator to be in mechanical communication with the valve; placing a fluid injection line in fluid communication with the valve such that the fluid injection line is also in operative communication with the fluid container; placing a fluid transport conduit in fluid communication with the fluid injection line; placing at least one pump for metering precise quantities of the fluid to be dispensed in fluid communication with the fluid transport conduit, thereby establishing fluid communication between the pump and the fluid container; selectively introducing a pusher fluid into the fluid transport conduit to force the flow of the fluid to be dispensed through the fluid transport conduit; monitoring the flow of the fluid to be dispensed through the fluid injection line with a flow detection system; controlling the opening or closing of the valve in response to a predetermined process condition by receiving an input from the controller, and sending a control signal from the controller to the valve actuator, thereby forcing engagement between the valve actuator and the valve to an extent dictated by the control signal such that the valve adjusts a flow of the fluid to be dispensed; and operating the pump to move a predetermined amount of the fluid to be dispensed from the fluid container, through the valve, fluid injection line, fluid transport conduit, and into a dispensing unit in fluid communication with the fluid transport conduit so as to accept fluid therefrom. The flow detection system itself comprises at least one detector placed in sensor communication with the fluid injection line and a controller in electrical communication with the detector, valve and pump such that upon detection and comparison of a flow variation, the controller sends signals to at least the pump or valve to control the flow of the fluid to be dispensed. Optionally, the fluid to be dispensed by the method is an acid, solvent or acid neutralizer. The method may further include a step to neutralize the etchant after use by dispensing an acid neutralizer with an integral dye indicator contained therein to indicate when a desired pH level is attained. This step could obviate the need to iteratively adjust the pH of the spent etchant.
[0016] In accordance with still another embodiment of the present invention, a method for preparing metallurgical etchants is disclosed, comprising the steps of: placing at least one fluid container with a fluid disposed therein in operative communication with at least one valve of a plurality of valves; arranging a valve actuator to be in mechanical communication with the valve; mounting a cam to both a shaft with an axis of rotation along its length and a rotational member with an axis of rotation along its length such that the cam is independently responsive to rotation of the shaft and rotational member; placing a cam driver for translating and rotating the cam relative to the valve in operative communication with both the shaft and rotational member; and controlling the opening or closing of the valve in response to a predetermined process condition. The step of controlling includes the following: receiving an input from a control mechanism; sending a control signal from the control mechanism to the cam driver; translating the cam until the cam is aligned with the valve actuator; and rotating the cam to force engagement between it and the valve actuator to an extent dictated by the control signal such that the valve actuator forces the valve to adjust a flow of the fluid therethrough. Optionally, the fluid to be dispensed is an acid, solvent or acid neutralizer, where the neutralizer can include an integral dye indicator.
[0017] Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The following detailed description of the preferred embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
[0019] [0019]FIG. 1 is a schematic of a general fluid flow path according to an embodiment of the present invention;
[0020] [0020]FIG. 2 is a schematic illustration of an enclosed fluid dispensing system of an embodiment of the present invention;
[0021] [0021]FIG. 3 is a schematic illustration of a valve arrangement according to an embodiment of the present invention;
[0022] [0022]FIG. 4 is a top view of a flow control apparatus with housing, cam assembly and a plurality of valves;
[0023] [0023]FIG. 5 is an isometric view highlighting the cam assembly of FIG. 4;
[0024] [0024]FIG. 6 is an illustration of a reagent fluid containment bottle with a stopper capping mechanism in accordance with an embodiment of the present invention; and
[0025] [0025]FIG. 7 is an illustration of an alternate embodiment stopper capping mechanism.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Referring first to FIG. 1, a general flowpath for a continuous fluid flow system 1 is shown. Pump 12 moves a reagent (comprising a mixture of individual fluids 13 , each of which are stored in container 14 ), through a conduit 15 to a fluid dispensing unit 16 , which holds a fluid receptacle 28 . Preferably, pump 12 is a metering syringe pump powered by a stepper motor (not shown), wherein during the suction phase, it draws fluid 13 out of container 14 into fluid injection line 22 , past a valve 18 . This process is repeated with as many fluids as is necessary to achieve the desired mixture. Once this is accomplished, pump 12 then pumps the mixture into the main stream of conduit 15 . Once the fluid is dispensed into fluid receptacle 28 , it is mixed, preferably through a magnetic stirrer 17 . A series of valves 18 are employed to control the introduction of fluids 13 into conduit 15 .
[0027] One or more flow sensors 21 (alternately referred to as detectors) are used in various locations in the flowpath to detect fluid flow. Sensor 21 works by sensing the presence of air pockets, either inherently present in the conduit 15 or fluid injection line 22 , or in the form of injected bubbles 20 . Preferably, the sensor includes a detector and a signal transmitter, both of which are mounted to a common board, such as a printed circuit board (PCB) 21 A, 21 B and 21 C, where PCBs 21 A, 21 B and 21 C are adapted to fit around the fluid injection lines 22 , conduit 15 or pressure relief tube 27 B, depending on the application. Although the sensors 21 are shown notionally mounted to three separate PCBs 21 A, 21 B and 21 C, they could also be mounted to a single elongate PCB (not shown). In the present invention, sensors 21 may be either ultrasonic, optical, or any other type of device capable of sensing flow changes and converting the sensed signal into a machine or human readable flow number. One suitable optical sensor includes light- or infrared-emitting diodes (LEDs and IREDs, respectively) arranged to transmit a signal to a phototransistor. Although the sensors could also be used to monitor flow rate, it is for measuring discrete quantities of fluid to be injected that they find their primary use in the present invention. For example, each cycle of metering pump 12 (which may be controlled by the aforementioned stepper motor) is designed to suction a precise quantity of fluid 13 present in fluid injection line 22 . However, the presence of air pockets (not shown) in the fluid injection line 22 , which is indiscriminately drawn up into the pump 12 for mixing, can result in less than the desired quantity of fluid 13 to be drawn up into pump 12 for mixing. The presence of sensors 21 on PCB 21 A is designed to prevent these inaccuracies by permitting the density, frequency or spacing of these air pockets within the fluid injection line 22 to be detected, then correlated with the amount of fluid 13 to be aspirated through the use of an automated feedback control arrangement, which is usually a microprocessor-based device such as controller 23 . The automated feedback control arrangement will typically utilize algorithms to detect the presence of air pockets in the fluid injection line 22 picked up by sensors 21 on PCB 21 A. This precise interactive control of the fluid metering components ensures reliable, highly repeatable resulting mixtures.
[0028] A bubble injection mechanism controls, via bubble injection valve 19 A, the introduction of bubbles 20 of an immiscible gas, such as air, into conduit 15 to provide thorough and precise quantities of the mixed reagent being discharged from pump 12 . It is noted that in the event a liquid “pusher” is desired over an immiscible gas, the bubble injection valve 19 A (or an equivalent) could be utilized, preferably in the same general location. Similarly, if a liquid pusher is used, a filter device can be added to ensure that particulate contamination is not introduced into the mixed reagent, as well as providing damping benefits to ensure proper fluid injection, mixing and transport. Sensor 21 mounted to PCB 21 B can be used to detect flow of fluid 13 from container 14 . In another adaptation, sensor 21 can be mounted to PCB 21 C to detect the presence of any flow through pressure relief tube 27 B and valve 24 into waste receptacle 25 . Bubbles 20 can provide, in addition to a “pusher” fluid to move fluid 13 , contamination reduction features, which due to the scrubbing action of bubbles 20 as they traverse conduit 15 remove fluid droplets from the line that could contaminate a subsequent mixture, as well as optional flow rate measuring capability, as previously mentioned. In performing their flow measuring function, the bubbles 20 are first injected by bubble injection valve 19 A into the conduit 15 upstream of the location where the fluid reagents 13 are to be inserted. One or more of the sensors 21 are placed downstream of the reagent insertion location, such as on PCB 21 B, and usually through either optical or sonic means, detects the flow rate based on the bubble flux. The sensor 21 sends a signal, typically in the form of a voltage, to a controller 23 for comparison to a predetermined flow constant. Based on a comparison of the measured flow rate with the flow constant, the controller 23 can provide active feedback to determine how much and how fast fluid reagent should flow through the main stream of the conduit 15 , and then into either fluid receptacle 28 or waste receptacle 25 through pressure relief valve 24 , which is included as a system safety measure. Drain 26 and waste tube 27 A are situated on a lower surface of fluid dispensing unit 16 to ensure that any spilled fluid is also routed to waste receptacle 25 . Dispensant control valve 19 B is coupled to the controller 23 (coupling line not shown to minimize drawing complexity) to ensure that reagent is isolated from fluid receptacle 28 during periods where pressure relief valve 24 is activated. Similarly, dispensant control valve 19 B is closed when pump 12 is aspirating liquids during its suction phase.
[0029] As shown in FIG. 2, a continuous fluid dispensing system 1 includes an enclosure 10 , a pump 12 with a motor 29 (which is typically a stepper motor or servomotor), a fluid dispensing unit 16 a part of which includes a fluid dispensing nozzle 16 A, and a fluid transport conduit 15 . The exterior dimensions of fluid dispensing system 1 are such that the system can fit in a conventional laboratory fume hood 2 with sliding glass front door 2 A, and on top of a stand 3 , under which a plurality of fluid containers 14 can be stored. Passage of fluid injection lines 22 from enclosure 10 to stand 3 can be accomplished by mating apertures (not shown) on respective surfaces of the two. While in the preferred embodiment the pump 12 can be the aforementioned syringe pump, the inventors recognize that other types of pumps capable of precise metering of the desired fluid are equally valid substitutes. The space defined by fluid dispensing unit 16 is user-accessible via an opening in an upstanding wall (not shown) of enclosure 10 , with such opening covered by a safety door 31 slidably mounted on the upstanding wall and positioned to block user access to fluid dispensing unit 16 and fluid dispensing nozzle 16 A during operation. An optional safety interlock system (not shown) is added as a failsafe way to ensure fluid dispensing system 1 does not operate until safety door 31 is closed, thus preventing the inadvertent discharge of fluid 13 to the environment, the user, or both. Housing 32 is used to support the plurality of valves 18 , which are used to fluid connect conduit 15 and pump 12 to dispensing unit 16 and dispensing nozzle 16 A. Housing 32 is preferably placed at an incline to further ensure that any fluids in the main stream of conduit 15 drain, by the force of gravity, to the lowermost position, thus reducing the incidence of conduit wall buildup of droplets. Enclosure 10 further includes ventilation holes 33 A and 33 B, as well as exhaust tube 33 C and exhaust stack 33 D to facilitate venting of enclosure 10 and dispensing unit 16 . Exhaust stack 33 D can be further integrated into the ventilation duct (not shown) of fume hood 22 , which can in turn be pumped away by facility ventilation systems (not shown). The ventilation enabled by ventilation holes 33 A and 33 B, exhaust tube 33 C and exhaust stack 33 D is useful in situations where fluid 13 emits noxious or corrosive fumes, which absent purging airflow through the enclosure 10 , could present a hazard to users as well as hasten the degradation of exposed components.
[0030] Referring now to FIG. 3, one representative valve 18 of the plurality of valves 18 housed in housing 32 is shown. The valve 18 includes a valve stem 40 that is biased by a spring 41 in a closed position. To open valve 18 , a pushrod actuator 42 is forced by cam 51 (described in more detail later) against a rear stop member 43 of valve stem 40 , thus causing valve stem 40 to overcome the spring bias, and creating an open path for fluid 13 to be suctioned up by pump 12 to flow from container 14 , through fluid injection line 22 , and into conduit 15 . O-rings 44 are placed in grooves 45 of valve stem 40 to provide leak-resistant sealing around valve inlet 46 . Each of the valves 18 are mounted inside housing 32 , as well as to cover plate 47 . Container 14 , which holds a supply of fluid 13 , is situated vertically below valve 18 so that excess fluid could be gravity-fed back into the container 14 . Flow sensor 21 is mounted on PCB 21 A, which is designed to fit around the fluid injection line 22 . The connection between container 14 and valve 18 is secured and sealed by gland nut 48 and ferrule 49 . In a preferred embodiment, the containers 14 are bottles, and are constructed of a material that can withstand chemical attack from the fluid therein. Where the fluid reagents are corrosive (such as an acid), the fluid-exposed components, including tubes, lines, conduits, containers, seals and O-rings are made from glass, fluoroelastomers such as Viton®, perfluoroelastomers such as Kalrez®, or related material such as Teflon® or polytetrafluoroethylene (PTFE).
[0031] Referring now to FIGS. 4 and 5, flow control apparatus 30 includes housing 32 , which contains a cam assembly 50 and a plurality of fluid injection valves 18 , as well as bubble injection valve 19 A, dispensant control valve 19 B, and pressure relief valve 24 . Each of the valves 18 are connected to an individual container 14 , as well as to conduit 15 . The valves 18 are preferably aligned in such a way so as to be readily accessible to being in mechanical communication with the single cam 51 , either in a single line as shown, or in dual parallel lines with the cam 51 spaced parallel to and equidistant between them (not shown). Once aligned, the cam 51 is then rotated so that its inherent eccentricity will engage the valve's actuator 42 , thereby forcing a change in the amount of fluid allowed to flow through the valve 18 . By this arrangement, the single cam 51 can control the movement of every valve, one at a time by responding to motor-driven signals from microprocessor-based controller 23 .
[0032] Cam assembly 50 comprises cam 51 , shaft 52 , rotational member 53 , bushing 54 , first motor 55 and second motor 56 . By translating up and down the length of the shaft 52 , cam 51 can be positioned in relation to any one of the valves 18 . Then, by rotating, cam 51 can actuate any one of the valves 18 according to predetermined needs for a particular fluid. Preferably, shaft 52 is a smaller diameter generally cylindrical cross section lead screw shaft, which imparts translational movement to cam 51 . In addition to being mounted to shaft 52 , cam 51 is mounted to the rotational member 53 , which is of larger diameter than shaft 52 . In the present context, when one object is “mounted” to another, it means that the objects are in direct, uninterrupted, contiguous mechanical communication with one another, with no other components in between. Thus, one can either be pivotally or rotatably attached to the other (such as through a hinge, bearing or pivot), or simply supported on the other (such as in an unattached, resting relationship), or the objects can be conventionally attached to each other (such as by bolting, gluing, screwing, welding, soldering, and the like). Rotational member 53 , which includes a larger diameter cam engaging section 53 A, smaller diameter cam driver engaging section 53 B, hollow center section 53 C and generally planar surface 53 D, imparts rotational movement to cam 51 . The axes of rotation of the cam 51 , shaft 52 and rotational member 53 are coaxial, with shaft 52 disposed inside the hollow center section 53 C of rotational member 53 , terminating in a receiving cup (not shown) at a distal end of hollow center section 53 C which, along with bushing 54 disposed between shaft 52 and rotational member 53 at a proximal end of hollow center section 53 C, maintains proper alignment between the shaft 52 and rotational member 53 . Specifically referring to FIG. 3, wherein shaft 52 and rotational member 53 are viewed looking down their mutual axis of rotation, and with bushing 54 removed for clarity, rotational member 53 defines a truncated cylindrical cross section, revealing a generally planar surface 53 D that engages cam 51 , while simultaneously permitting uninhibited connection between shaft 52 and cam aperture 51 B, where the size of aperture 51 B is shown exaggerated and without helical-shaped threads 52 A for clarity. The combined translational and rotational movement of cam 51 is referred to as motion in two degrees of freedom. As used herein, the term “degrees of freedom” coincide with the convention used in solid or continuum mechanics, where a continuous medium in Euclidean space can experience a total of six degrees of freedom of motion: three translational (along each of the x, y and z axes in a Cartesian system), and three rotational along each of the same three axes.
[0033] Shaft 52 is aligned with rotating member 53 by bushing 54 . Shaft 52 , rotational member 53 , first motor 55 and second motor 56 are conventionally mounted to housing 32 , while bushing 54 is mounted to both shaft 52 and rotational member 53 . Translation movement of cam 51 is achieved by using the first motor 55 , disposed at one end of housing 32 , to turn shaft 52 . Helical-shaped threads 52 A extend substantially between opposing ends of the outer surface of shaft 52 , and engage inner surface 51 A of an aperture 51 B in cam 51 , which is complementary threaded. Once cam 51 is put into aligned relationship with pushrod 42 of a selected valve 18 , rotational movement of cam 51 can be achieved by using the second motor 56 disposed at the opposing end of housing 32 to turn rotational member 53 . Upon rotation, eccentric portion 51 C of cam 51 comes into contact with pushrod 42 , forcing it to open or close valve 18 to its desired position, which, in turn, alters the amount of flow through fluid injection line 22 , which is mounted in gland nut 48 and ferrule 49 . While the configuration of FIGS. 4 and 5 depict the use of two motors, one for each of rotational and translational movement, it is noted that a single motor could be used to provide both forces through, for example, a clutch or gearing arrangement between the motor, shaft and rotational member. Regardless of the number of motors used to provide cam 51 movement, it is noted that conventional stepper or servomotors provide reliable, inexpensive power. In addition, while the embodiment depicted in FIG. 5 notionally includes four valves, it is readily appreciated that the present invention can accommodate any number of valves, limited only by the needs of the end use application.
[0034] Referring now to FIG. 6, capping mechanism 60 acts as a stopper to be placed in the aperture 14 A of container 14 to allow the insertion and removal of fluid from container 14 while simultaneously limiting exposure of the fluid (not shown) disposed therein to the ambient environment, in order to inhibit spillage of the fluid or release of vapors. Capping mechanism 60 is made up of a body 60 A, with threads 60 B disposed on the outer surface thereof to engage a complementary threaded inner surface of top 60 C and body disengaging nut 60 L. Vent membrane 60 D and membrane plate 60 E, each with substantially centrally disposed channels 60 F, 60 G, respectively are axially-aligned disk-like members that fit in chamber 60 K disposed in the top of body 60 A such that they rest on ledge 60 M. Vent membrane 60 D, which is typically made of a compliant elastic material, such as Viton®, includes a plurality of slits 60 H disposed circumferentially about channel 60 F. These slits 60 H can open in response to pressure differentials across the surface of vent membrane 60 D. Recesses 60 J, substantially axially aligned with slits 60 H, permit fluid communication between chamber 60 K (which itself is in fluid communication with the gaseous region inside container 14 above the liquid line 13 A by virtue of passage 60 N being of slightly greater diameter than fluid injection line 22 ) and the ambient environment. Top 60 C, through threaded engagement with threads 60 B, secures vent membrane 60 D and membrane plate 60 E in an axially fixed position relative to chamber 60 K. Body disengaging nut 60 L, with internal threads (not shown) to engage threads 60 B of body 60 A, is used to gently but firmly remove capping mechanism 60 from aperture 14 A. Fluid injection line 22 can frictionally engage channels 60 F and 60 G to secure fluid injection line 22 in place. Passage 60 N is axially disposed in body 60 A and extends from the bottom of the chamber 60 K through to the bottom plug portion 60 P, thereby allowing gas in container 14 to be vented through slits 60 H and recesses 60 J upon return of liquid through fluid injectant line 22 to container 14 . During aspiration of liquid into fluid injectant line 22 as a result of suction applied to fluid injectant line 22 , air enters the container 14 through slits 60 H, recesses 60 J, chamber 60 K, and passage 60 N. Note that a second membrane plate (not shown) identical to membrane plate 60 E could be situated under vent membrane 60 D to create a stacked, sandwich structure. Such a configuration could be included in the event that additional support of vent membrane 60 D is desired. The portion of capping mechanism 60 designed to fit inside the aperture can optionally include one or more O-ring grooves (not shown) with inserted O-rings 70 .
[0035] Alternatively, for containers 14 which have external threads on the neck of the bottle (not shown), the capping arrangement previously described can be simplified; in this case including solely an oversized variant (not shown) of threaded top 60 C with a smaller opening (not shown) sized to accommodate the fluid injection line 22 , membrane plate 60 E and vent membrane 60 D. The internal threads on the oversized top would engage the external threads on the neck of the container 14 , while an arrangement of vent membrane 60 D and one or more membrane plates 60 E can be axially disposed between the threaded top and the top of the neck of container 14 . Fluid is transferred either into or out of the container 14 in the same manner as above. As previously discussed, two membrane plates 60 E may be used to sandwich a single vent membrane 60 D in this arrangement.
[0036] Referring now to FIG. 7, an alternate embodiment of the capping mechanism shown in FIG. 6 is shown, with capping mechanism 160 and spherical-shaped stopper members 161 , 162 , which together comprise a two-way vent. During the suction phase, where fluid 13 is being dispensed from container 14 through fluid injection line 22 , a partial vacuum is created in fluid injection line 22 which, due to it being in fluid communication with venturi 163 C through fluid 13 , the gaseous region above the liquid line 13 A, and the gap between fluid injection line 22 and access tube 164 in capping mechanism 160 , draws in higher pressure ambient air from outside the container 14 . For ambient air to reach venturi 163 C, it is necessary that it push smaller sphere 161 out of the way. The weight of smaller sphere 161 is such that the incoming air is of sufficient pressure to cause smaller sphere 161 to raise up off of small seating throat 165 , thus admitting air into container 14 via passages 163 A and 163 B and venturi 163 C. The incoming air, which is in fluid communication with the gaseous region inside container above liquid line 13 A through gaps between fluid injection line 22 and access tube 164 , exerts pressure on fluid 13 , pushing it up and into fluid injection line 22 . When the pressure is equalized, smaller sphere 161 reseats on small seating throat 165 . During the fluid input phase, the process is reversed. Increased pressure in the fluid injection line 22 forces smaller sphere 161 even more forcefully against small seating throat 165 . In addition, the higher pressure overcomes the gravitational force on larger sphere 162 , and lifts it off large seating throat 166 , placing a vent port 167 (and the lower pressure ambient air) in fluid communication with the higher pressure gaseous region situated above liquid line 13 A in container 14 . Larger sphere 162 is massive enough so as to positively reseat upon return to pressure equilibrium between container 14 and the ambient environment, and in so doing, reduces the likelihood that the enclosed fluid will evaporate. It is also noted that smaller sphere 161 and larger sphere 162 could both have their seating enhanced by the addition of O-rings (not shown). Ambient conditions are defined as those which exist outside of a fluid's primary container, and typically include pressures and temperatures found in normal industrial or laboratory settings. Thus, if the fluid resides in a bottle, the environment outside the bottle is considered “ambient”, even if the bottle is itself contained within another, larger enclosure. The reduction in the likelihood of evaporation is important for fluids with high vapor pressures, such as acids and solvents. The portion of stopper 160 above the aperture of the container 14 can optionally have grooved outer surface, to engage a threaded top (not shown for clarity). The top facilitates easier, safer removal; by screwing the top down, it interacts with the grooves in capping mechanism 160 to gently, but smoothly lift capping mechanism 160 out of the container aperture, thereby preventing a recoil or snapping action when the capping mechanism 160 finally disengages from the container 14 . As with the previous embodiment, the portion of capping mechanism 160 beneath the aperture can optionally include O-ring grooves 168 . Their inclusion, in conjunction with inserted O-rings 170 , also helps prevent the sudden, often violent snapping action of the container upon removal of capping mechanism 160 . Fluid injection line 22 is friction fitted into the uppermost portion of capping mechanism 160 , with sealing provided by an additional set of O-rings 171 disposed near the top.
[0037] Having described the invention in detail and by reference to the aspects thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention which is defined in the appended claims:
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An apparatus for the control of fluid flow through a valve. A single shaft-mounted cam moves translationally along the length of the shaft, stopping sequentially at positions adjacent to and in operative engagement with an actuator disposed on or near a valve body. Once in position with a predetermined valve, the cam, which is also coupled to a rotational member, is rotated, thus causing an eccentric portion of the cam to engage the actuator in such a way so as to force the valve to open or close. A flow detection system is integrated into a main fluid transport conduit, allowing sensed flow variations to be sent to a controller. The controller uses a comparison algorithm to determine what fluid settings in the valve are necessary to effect a desired fluid flow through the valve, and prepares an input signal to be sent to one or more motors controlling the translational and rotational motion of the cam. Capping devices and an enclosure with a safety door can be included to protect personnel and the ambient environment against fluid spillage.
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FIELD OF THE INVENTION
The present invention relates to novel chlorotrialkoxyethane compounds and to a facile method for making these compounds. In addition, a method of using chlorotrialkoxyethane compounds as intermediates in the manufacture of other useful compounds is provided by the invention.
BACKGROUND OF THE INVENTION
Glyoxal, typically sold as a 40% aqueous solution, is an inexpensive chemical with a variety of industrial uses, most importantly for treatment of cellulosic textiles. The known bis(dialkyl acetal) derivatives of glyoxal of the formula:
(RO).sub.2 CHCH(OR).sub.2
are readily prepared in high yield (80-100%, depending on the nature of "R"). In contrast, the corresponding monoacetal derivatives of glyoxal of the formula:
(RO).sub.2 CHCHO
are much more difficult to prepare although the monoacetal derivatives of glyoxal are potentially versatile intermediates in organic synthesis. Current industrial-scale preparations of monoacetal derivatives have generally been avoided due to the difficulties inherent in previously-known routes which often require the use of hazardous reagents, lengthy reaction sequences, expensive reagents, and/or which result in complex product mixtures.
Different processes for making monoacetal derivatives of glyoxal have been reported. For example, ozonolysis of 3,3-dialkoxypropenes (acrolein dialkyl acetals) at low temperatures, followed by subsequent reduction with triphenylphosphine is reported to give a dialkoxy aldehyde, H. J. Bestmann and P. Erman, Chem. Ber., 116:3264 (1983). A multi-step process that uses comparatively expensive specialty chemicals (e.g., 3-ethoxyacrylonitrile and N-bromosuccinimide) is also reported to give a dialkoxy aldehyde, J. H. Babler, Synth. Commun., 17:77 (1987). Oxidation of commercially available, but expensive, 2,2-diethoxy-1-ethanol (glycolaldehyde diethyl acetal) to give the dialkoxy aldehyde is reported by D. Bernard, A. Doutheau, and J. Gore, Synth. Commun. 17:1807 (1987).
Partial acetalization of aqueous glyoxal is reported by A. Stambouli et al., Bull. Soc. Chim. France, 95 (1988). Although this reported one-step method yields 2,2-dialkoxyethanals (i.e., monoacetal derivatives of glyoxal), careful monitoring of the reaction is required to avoid acetalization of both carbonyl groups of glyoxal; the yield of monoacetal product is only moderate (50-70%). A reported improvement for this type of acetalization reacts various 1,3-propanediol reagents with glyoxal in 1,2-dichloroethane at high temperatures, but the monoacetal derivatives obtained in this manner are isolated only after careful vacuum distillation and frequently several repetitions of the high-temperature process may be necessary to obtain an acceptable yield. See European Patent 316,672 (Nov. 4, 1988).
Finally, a single monoacetal glyoxal derivative, (CH 3 O) 2 CHCHCl(OCH 3 ), has been reported by Bou et al., Tetrahedron, 37:1441-1449 (1981). This derivative was obtained as a minor component of a reaction mixture which resulted in the formation of the sought-after dichloro compound (CH 3 O)ClCHCHCl(OCH 3 ) as the major product.
As noted above, monoacetal derivatives of glyoxal have potential use in a variety of synthetic processes. For example, the compound (RO) 2 CHCHO is reportedly used in the manufacture of vitamin A. See, European Patents 246,646 (May 21, 1987) and 316,672 (Nov. 4, 1988). Alpha-halo ethers derived from glyoxal, due to the high reactivity of the carbon-chlorine bond in such compounds in nucleophilic substitution reactions, are attractive intermediates in the manufacture of several known industrial compounds, as well as prospective intermediates in the manufacture of various known or novel specialty organic chemicals.
Another example of the synthetic utility of 1-chloro-1,2,2-trialkoxyethanes involves their reaction with primary amines. For example, reacting these copounds with benzylamine gives the intermediate (RO) 2 CHCH═NCH 2 Ph, in high yield. This intermediate may be readily converted to isoquinoline, a heterocyclic compound with extensive industrial uses, by treatment with aqueous acid as reported by E. Schlittler and J. Muller, Helv. Chim. Acta., 31:914 (1948). Glyoxal monoacetal derivatives may also be used to prepare, various alpha, beta-unsaturated aldehydes, unsymmetrically-substituted 1,3-dienes, and numerous other compounds of the general structure W═CH--CH═Z (W≠Z).
In view of the broad application of monoacetal derivatives of glyoxal to synthetic methodology, a need exists for a facile method of preparing these derivatives using inexpensive, readily-available reagents and solvents.
SUMMARY OF THE INVENTION
The present invention provides a process for preparing monoacetal derivatives of glyoxal as well as other useful related compounds. Besides the high overall yields, up to about 90% from aqueous glyoxal, this method offers two additional advantages: (a) differentially functionalized two-carbon building blocks, not readily accessible from glyoxal monoacetal derivatives, and (b) novel 1-chloro-1,2,2-trialkoxyethanes that are reasonably stable compared to known monoacetal derivatives of glyoxal which are susceptible to polymerization during purification or subsequent reactions. The alpha-chloro ethers provided by the present invention may be converted to other useful compounds (e.g., isoquinoline and acetal derivatives of aminoacetaldehyde) without the need for generating unstable glyoxal monoacetal derivatives themselves.
A first step of the method of this invention includes conversion of aqueous glyoxal to bisacetal derivatives, (RO) 2 CHCH(OR) 2 , using primary and secondary alcohols. Preferred alcohols include ethyl alcohol, allyl alcohol (2-propen-1-ol), 1-butanol, and cyclohexanol. Other simple monohydric alcohols are also suitable (e.g., methyl alcohol, 1-propanol, isopropyl alcohol and isobutyl alcohol). Typically, yields for the acetal formation step are high, ranging from 80 to 100%. ##STR1##
Specific yields of bisacetal in this first step are as follows: when R is butyl, about 97%; when R is methyl or ethyl, about 80% (F. Chastrette et al., Synth. Commun. 18:1343 (1988); and when R is allyl, about 83% (Belgian Patent 609,343 (Apr. 19, 1962), and Chem. Abstracts. 57:10037h (1962)).
A second step of the method of this invention includes conversion of the bisacetal derivatives of glyoxal to a 1-chloro-1,2,2-trialkoxyethane using hydrogen chloride, preferably as a catalyst, in the presence of one equivalent of a chloride reagent such as acetyl chloride or thionyl chloride which continuously regenerates HCl as the reaction proceeds. Unexpectedly, no 1,2-dichloro-1,2-dialkoxyethanes were obtained, even in the presence of an excess of acetyl chloride or similar reagents. ##STR2##
The hydrogen chloride that is needed to initiate the second step may be generated by addition of a catalytic amount of ROH or H 2 O to a chloride-containing reagent, such as acetyl chloride or thionyl chloride. Carboxylic acid chlorides are preferred because these compounds scavenge the alcohol which is liberated as the reaction proceeds, thereby continuously regenerating the necessary hydrogen chloride.
When acetyl chloride is used for this step, no aqueous work-up is needed; only simple distillative removal of volatile organic material, CH 3 CO 2 R, at slightly reduced pressure is needed in order to isolate the desired 1-chloro1,2,2-trialkoxyethanes. Alternatively, it is possible to add aqueous sodium bicarbonate to the crude reaction mixture and proceed to the next step (conversion to glyoxal monoacetal derivatives) without removal of the acetate ester.
Although acetyl chloride or thionyl chloride are preferred reagents for effecting the transformation of step 2, the following reagents may also be used (albeit with lower yields or prolonged reaction times): carboxylic acid chlorides such as propionyl chloride, crotonyl chloride, trimethylacetyl chloride, or benzoyl chloride; phosphorus trichloride or phosphorous oxychloride (POCl 3 ); chlorotrimethylsilane; sulfonic acid chlorides such as methanesulfonyl chloride; and sulfuryl chloride (SO 2 Cl 2 ).
Alternatively, at least one equivalent of HCl gas may be bubbled into the reaction mixture if aprotic solvents are used. For example, hydrogen chloride in various aprotic organic solvents such as dioxane, tetrahydrofuran, acetonitrile, ethyl acetate, toluene, methylene chloride, heptane, cyclohexane, or mixtures thereof may be used in the present method. Use of HCl in organic solvents not capable of scavenging the by-product alcohol, ROH, results in a product mixture containing a substantial amount (often 25%) of starting bisacetal which is presumably formed because the liberated alcohol can function as a weak nucleophile, displacing the chloro substitutent in the intermediate compound ##STR3## produced by the present method.
The chlorination step is generally conducted at room temperature, but proceeds rapidly at 0° C. in sulfuryl chloride. Use of certain chloride containing reagents such as benzoyl chloride or methanesulfonyl chloride in this reaction results in a slower process and may necessitate gentle heating (i.e., 50°-100° C.).
Unexpectedly, analysis of the crude products of the present method by proton NMR spectrometry, even when excess of acetyl chloride or thionyl chloride are utilized, failed to detect any significant amount of the "dihalo" product, ##STR4## which would not be useful in preparing monoacetal derivatives of glyoxal.
The fact that the present method results in the formation of only the alpha-halo ether is surprising in view of the transformation outlined below involving glyoxal bisacetal derivatives that was recently reported by A. Stambouli et al., Tetrahedron Lett., 27:4149 (1986). ##STR5##
The formation of Product B (containing acetoxy groups at both carbon atoms) in a roughly statistical proportion was expected. When one treats a symmetrical compound containing two identical functional groups with only one equivalent of a reagent, a "statistical mixture" of products (i.e., approximately 50% of the monoderivatized product and 25% of the bisderivatized product) would be expected. The method of the present invention, however, provides substantially no dihaloethers.
In a third step of the present method, the chloride may be displaced by a nucleophile. ##STR6## For example, the displacement of chloride by water (hydroxide) is very facile, reaction being complete in less than one hour at 0° C. In order to increase the solubility of the alpha-chloro ether in the reaction mixture, organic solvents such as dimethylformamide, 1-methyl-2-pyrrolidinone, or tetrahydrofuran may be added to the reaction mixture. Prior to being heated in toluene, the initial reaction mixture includes a mixture of ##STR7## (RO) 2 CHCH(OH) 2 , the hydrate of glyoxal monoacetal, and (RO) 2 CHCHO, glyoxal monoacetal. Heating then provides the monoacetal in high yield.
Other nucleophiles that are able to displace the chloride in these alpha-halo ethers include carboxylate anions, primary amines, nitrite salts, thiols, malonate, and cyanide.
An example illustrating the versatility of 1-chloro-1,2,2-trialkoxyethanes of the present invention is outlined below: ##STR8##
By avoiding formation of the rather unstable, known glyoxal monoacetal derivatives, this route to isoquinoline is a significant improvement over known routes. In an analogous manner, treatment of 1-chloro-1,2,2-trialkoxyethanes with sodium nitrite in a polar, aprotic solvent, after reduction of the intermediate, provides acetal derivatives of aminoacetaldehyde, which are used to prepare a variety of heterocycles important in the pharmaceutical industry.
Another use for monoacetal derivatives of glyoxal involves a crossed aldol reaction with propionaldehyde, a transformation that was published in Liebigs Ann. Chem., (1976), as outlined below: ##STR9## The product is reported to be a useful intermediate in the manufacture of vitamin A. See European Patent 246,646 (May 21, 1987).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an NMR spectrum of a bis(dialkyl acetal) glyoxal derivative prepared according to the procedure of Example I.
FIG. 2 is an NMR spectrum of a bis(dialkyl acetal) glyoxal derivative prepared according to the procedure of Example II.
FIG. 3 is an NMR spectrum of a chlorotrialkoxy glyoxal derivative prepared according to the procedure of Example IV.
FIG. 4 is an NMR spectrum of a mixture of glyoxal derivatives prepared according to Example IV.
FIG. 5 is an NMR spectrum of a chlorotrialkoxy glyoxal derivative prepared according to the procedure of Example V.
DETAILED DESCRIPTION OF THE INVENTION
The following examples illustrate specific embodiments of the practice of the method of the present invention. Bisacetal derivatives of glyoxal prepared according to known procedures are described in Examples I, II, and III. The conversion of these bisacetal derivatives to 1-chloro-1,2,2-trialkoxyethanes is described in Examples IV-XVI. Displacement of the chloride in these 1-chloro-1,2,2-trialkoxyethanes by representative nucleophiles is described in Examples XVII, XVIII, and XIX.
EXAMPLE I
Preparation of Glyoxal Bis(Dibutyl Acetal)
A mixture containing 4.17 g (28.7 mmoles) of glyoxal (40 wt. % solution in water), 13.0 mLs (142 mmoles) of 1-butanol, and 175 mg (0.92 mmole) of p-toluenesulfonic acid monohydrate in 8.00 mLs of benzene was heated at reflux for 6.5 hours with continuous azeotropic removal of water. The cooled mixture was diluted with 25 mLs of ether and washed in successive order with saturated aqueous sodium bicarbonate (20 mLs) and saturated brine (20 mLs). The washed organic layer was then dried over anhydrous sodium sulfate and filtered. Removal of the volatile organic solvents under reduced pressure, followed by evaporative distillation, afforded 8.89 g (97% yield) of the named bisacetal: boiling point 118°-130° C. (bath temperature, 0.25 mm). The identity and purity of this bisactal were ascertained by proton NMR analysis. A copy of the NMR spectrum is provided in FIG. 1. A less pure sample of this compound has previously been prepared, using a modified procedure, by J. M. Kliegman and R. K. Barnes, J. Org. Chem., 38:556 (1973).
EXAMPLE II
Preparation of Glyoxal Bis(Diethyl Acetal)
A mixture containing 8.20 g (56.5 mmoles) of glyoxal (40 wt. % solution in water), 14.0 mLs (239 mmoles) of absolute ethanol, and 343 mg (1.8 mmoles) of p-toluenesulfonic acid monohydrate in 25 mLs of benzene was heated at reflux for 8 hours with continuous azeotropic removal of water. The cooled mixture was then concentrated under reduced pressure to a volume of approximately 15 mL, after which it was diluted with 10 mL of saturated aqueous sodium bicarbonate and 80 mL of 10% aqueous sodium chloride. The product was removed from the aqueous layer by extraction with methylene chloride (3×40 mL). The combined organic extracts were washed with 15% aqueous sodium chloride (80 mL), then dried over anhydrous sodium sulfate and filtered. Removal of the methylene chloride under reduced pressure, followed by fractional distillation, afforded 4.17 g (36% yield) of the named bisacetal: boiling point 80°-85° C. at 5 mm. The identity and purity of this bisacetal were ascertained by proton NMR analysis. A copy of the NMR spectrum is provided in FIG. 2. This same compound can be prepared in greater than 80% yield using the modified procedure of F. Chastrette et al., Synth. Commun., 18:1343 (1988).
EXAMPLE III
Preparation of Glyoxal Bis(Dicyclohexyl Acetal)
The reaction was conducted in the manner described in the procedure of Example I using the following reagents: 2.096 g (14.45 mmoles) of glyoxal (40 wt. % solution in water), 7.00 mL (67.3 mmoles) of cyclohexanol, 88 mg (0.46 mmole) of p-toluenesulfonic acid monohydrate, and 5.00 mL of benzene. Isolation of the product as described in the procedure of Example I, followed by evaporative distillation, afforded 5.83 g (95% yield) of the named bisacetal: boiling point 205°-212° C. (bath temperature, 0.30 mm).
EXAMPLE IV
Preparation of 1-Chloro-1,2,2-triethoxyethane Using Acetyl Chloride to Generate HCl
In order to generate a small amount of hydrogen chloride, 8 mg (0.17 mmole) of absolute ethanol was added to a solution of 197 mg (0.955 mmole) of glyoxal bis(diethyl acetal) (produced in accordance with Example II) in 0.25 mL (3.52 mmoles) of freshly distilled acetyl chloride. On a larger scale, it would be necessary to use only slightly more than one equivalent of acetyl chloride to ensure complete reaction. Due to the high volatility of acetyl chloride, a large excess was used in this example in view of its relatively small scale. This mixture, protected from atmospheric moisture, was subsequently stirred at room temperature for 4.5 hours. Removal of the volatile organic material (ethyl acetate and excess acetyl chloride) under reduced pressure afforded 185 mg (98% yield) of the title compound. The identity and purity of this compound were ascertained by proton NMR analysis. A copy of the NMR spectrum is provided in FIG. 3.
A similar procedure was conducted without adding any ethyl alcohol. The reaction still proceeds since trace amounts of hydrogen chloride can be generated from acetyl chloride and adventitious water. However, proton NMR analysis of the crude product indicated the presence of 20-25% unreacted starting bisacetal. Thus, as expected, hydrogen chloride was shown to promote this reaction. A copy of the NMR spectrum is provided in FIG. 4. The presence of unreacted bisacetal is indicated by the singlet at approximately δ4.3.
EXAMPLE V
Preparation of 1-Chloro-1,2,2-tributoxyethane Using Acetyl Chloride to Generate HCl
In order to generate hydrogen chloride to initiate the reaction, 63 mg (0.85 mmole) of 1-butanol was added to a solution of 626 mg (1.97 mmoles) of glyoxal bis(dibutyl acetal) (produced in accordance with Example I) in 0.50 mL (7.04 mmoles) of freshly distilled acetyl chloride. This mixture, protected from atmospheric moisture, was subsequently stirred at room temperature for 2 hours. Removal of the volatile organic material (butyl acetate and excess acetyl chloride) under reduced pressure afforded 545 mg (98.6% yield) of the title compound. That the reaction had gone to completion and the product required no further purification were ascertained by proton NMR analysis. A copy of this NMR spectrum is provided in FIG. 5. No evidence is found in the spectra to indicate the presence of the dihalo derivative.
EXAMPLE VI
Preparation of 1-Chloro-1,2,2-triallyloxyethane Using Thionyl Chloride to Generate HCl
A mixture of 1.98 g (7.77 mmoles) of glyoxal bis(diallyl acetal) commercially available from Aldrich Chemical Company, Milwaukee, Wis., and 100 mL (13.7 mmoles) of thionyl chloride, containing trace amounts of HCl generated from adventitious water and thionyl chloride, was heated at 65° C. (external oil bath temperature) for 8.5 hours, during which time the mixture was protected from atmospheric moisture. After cooling this mixture to room temperature, it was diluted with 20 mLs of 1:1 (volume/volume) pentane:ether, and the organic layer was washed in successive order with ice-cold 1M aqueous sodium hydroxide (20 mL) and saturated brine (20 mL). The washed organic layer was then dried over anhydrous sodium sulfate and filtered. Removal of the volatile organic material under reduced pressure afforded 1.80 g of product, shown by proton NMR analysis to be the title compound contaminated with approximately 15% unreacted starting bisacetal. Subsequent experiments demonstrated that this reaction goes to completion (in less time) if a catalytic amount of allyl alcohol is added to the initial reaction mixture to generate HCl in situ.
EXAMPLE VII
Preparation of 1-Chloro-1,2,2-tributoxyethane Using Phosphorus Trichloride to Generate HCl
In order to generate hydrogen chloride to initiate the reaction, 18 mg (0.24 mmole) of 1-butanol was added to a mixture of 258 mg (0.81 mmole) of glyoxal bis(dibutyl acetal) (produced in accordance with Example I) and 0.25 mL (2.87 mmoles) of phosphorus trichloride. This mixture, protected from atmospheric moisture, was subsequently stirred at room temperature for 5 hours. After dilution of this mixture with 20 mL of 1:1 (volume/volume) pentane: ether, the product (239 mg) was isolated as described in the procedure of Example VI and shown by proton NMR analysis to be a 1:1 mixture of the desired alpha-chloro ether and unreacted starting bisacetal.
In a similar experiment conducted at 65° C. (external oil bath temperature) for 4 hours, using 253 mg of bisacetal, 0.25 mL of phosphorus trichloride, and no added 1-butanol, reaction to give the title compound was virtually complete.
EXAMPLE VIII
Preparation of 1-Chloro-1,2,2-tributoxyethane Using Gaseous Hydrogen Chloride in An Organic Solvent
To 0.25 mL of 1,4-dioxane saturated with gaseous hydrogen chloride was added a solution of 178 mg (0.56 mmole) of glyoxal bis(dibutyl acetal) (produced in accordance with Example I) in 0.25 mL of anhydrous ethyl ether. This mixture, protected from atmospheric moisture, was subsequently stirred at room temperature for 60 minutes, after which it was concentrated under reduced pressure to remove volatile organic material (1,4-dioxane, ether, and 1-butanol). The product (159 mg) was shown by NMR analysis to be a 3:1 mixture of the title compound and starting bisacetal, respectively. Longer reaction time failed to drive this reaction to completion, which seems to indicate that removal of the alcohol generated as the reaction proceeds is desirable.
Similar experiments were conducted using 1,4-dioxane saturated with gaseous HCl and an equal volume of various organic solvents including toluene, methylene chloride, acetonitrile, ethyl acetate, cyclohexane, and heptane. Although the desired alpha-chloro ether was obtained in all such experiments, the crude product mixture further contained unreacted starting bisacetal. Use of polar cosolvents such as acetonitrile also resulted in the formation of unidentified decomposition products.
EXAMPLE IX
Preparation of 1-Chloro-1,2,2-triallyloxyethane Using Acetyl Chloride to Generate HCl
In order to generate hydrogen chloride to initiate the reaction, 190 mg (3.27 mmoles) of allyl alcohol was added to a solution of 5.00 mL (19.7 mmoles) of glyoxal bis(diallyl acetal) commercially available from Aldrich Chemical Company, Milwaukee, Wis., in 2.00 mL (28.1 mmoles) of distilled acetyl chloride. This mixture, protected from atmospheric moisture, was subsequently heated at 45° C. (external oil bath temperature) for 2 hours. Removal of the volatile organic material (allyl acetate and excess acetyl chloride) under reduced pressure afforded 4.60 g (100% yield) of the title compound, contaminated with a trace amount of unreacted bisacetal.
EXAMPLE X
Preparation of 1-Chloro-1,2,2-triethoxyethane Using Thionyl Chloride to Generate HCl
To 203 mg (0.98 mmole) of glyoxal bis(diethyl acetal) (produced in accordance with Example II) was added 0.25 mL (3.4 mmoles) of thionyl chloride (97%), commercially available from Aldrich Chemical Company, Milwaukee, Wis.,; used without further purification. Since the thionyl chloride showed visible signs of containing a small amount of hydrogen chloride, presumably produced by reaction with atmospheric moisture, no attempt was made to generate more, in contrast to the experiment described in Example IV. Due to the volatility of thionyl chloride, it was used in large excess for this small-scale experiment to ensure complete reaction. As the reaction is scaled up, the quantity of thionyl chloride should be reduced--ultimately to about one equivalent. This mixture, protected from additional exposure to atmospheric moisture, was stirred at room temperature for 2.5 hours. The mixture was then diluted with 20 mL of 1:1 (volume/volume) pentane:ether; and the organic layer was washed in successive order with ice-cold 1M aqueous sodium hydroxide (20 mL) and saturated brine (20 mLs). The washed organic layer was subsequently dried over anhydrous sodium sulfate and filtered. Removal of the volatile organic material under reduced pressure afforded 191 mg (99% yield) of the title compound, shown by proton NMR analysis to be identical to the product obtained in accordance with Example IV.
EXAMPLE XI
Preparation of 1-Chloro-1,2,2-triethoxyethane Using Various Acid Chlorides to Generate HCl
A mixture of 142 mg (0.69 mmole) of glyoxal bis(diethyl acetal) (produced in accordance with Example II) and 0.10 mL (0.86 mmole) of benzoyl chloride was heated at 110° C. (external oil bath temperature) for 5.5 hours, during which time the mixture was protected from atmospheric moisture. After cooling this mixture to room temperature, it was analyzed by proton NMR spectroscopy and shown to contain ethyl benzoate and unreacted benzoyl chloride, accompanied by a 2.5:1 mixture of starting bisacetal and the title compound. Although no attempt was made to optimize this reaction, presumably the addition of a catalytic amount of ethyl alcohol (to generate HCl in situ) would have accelerated the process, in analogy to the experiment described in Example IV. Additional evidence that a variety of carboxylic acid chlorides could be used in this transformation was obtained by heating a mixture of 155 mg (0.75 mmole) of glyoxal bis(diethyl acetal) and 0.25 mL (2.6 mmoles) of crotonyl chloride at 65° C. (external oil bath temperature) for 3 hours. Such conditions resulted in the virtually complete conversion of starting bisacetal to the title compound.
In a similar manner, a mixture of 198 mg (0.96 mmole) of glyoxal bis(diethyl acetal) and 0.25 mL (3.2 mmoles) of methanesulfonyl chloride was heated at 90° C. (external oil bath temperature) for 5 hours. As expected in the absence of a catalytic amount of ethanol or water (to generate sufficient HCl), reaction to yield the title compound was quite slow (approximately 10% conversion) under these conditions.
EXAMPLE XII
Preparation of 1-Chloro-1,2,2-tributoxyethane Using Thionyl Chloride to Generate HCl
A mixture of 306 mg (0.96 mmole) of glyoxal bis(dibutyl acetal) (produced in accordance with Example I) and 0.25 mL (3.4 mmoles) of thionyl chloride (97%), commercially available from Aldrich Chemical Company, Milwaukee, Wis., used without purification, was stirred, while being protected from additional exposure to atmospheric moisture, at room temperature for 7.25 hours. Isolation of the product as described in the procedure of Example X afforded 264 mg (98% yield) of the title compound, shown by proton NMR analysis to be identical to the product obtained in accordance with Example V.
EXAMPLE XIII
Preparation of 1-Chloro-1,2,2-tributoxyethane Using Sulfuryl Chloride to Generate HCl
A mixture of 289 mg (0.91 mmole) of glyoxal bis(dibutyl acetal) (produced in accordance with Example I) and 0.25 mL (3.1 mmoles) of sulfuryl chloride was stirred, while being protected from exposure to atmospheric moisture, at 0° C. for 60 minutes. Isolation of the product as described in the procedure of Example X afforded 270 mg of a 2:3 mixture of the title compound and unreacted bisacetal, as shown by proton NMR analysis.
EXAMPLE XIV
Preparation of 1-Chloro1,2,2-triethoxyethane Using Chlorotrimethylsilane to Generate HCl
A mixture of 235 mg (1.14 mmoles) of glyoxal bis(diethyl acetal) (produced in accordance with Example II) and 0.50 ml (3.94 mmoles) of chlorotrimethylsilane was heated at 55°-60° C. (external oil bath temperature), while being protected from atmospheric moisture, for 6.25 hours. Removal of the volatile organic material at room temperature under reduced pressure afforded 230 mg of a 1:1 mixture of unreacted bisacetal and the title compound, as shown by proton NMR analysis.
EXAMPLE XV
Preparation of 1-Chloro-1,2,2-tributoxyethane Using Phosphorus Oxychloride to Generate HCl
A mixture of 237 mg (0.74 mmole) of glyoxal bis(dibutyl acetal) (produced in accordance with Example I) and 0.25 mL (2.7 mmoles) of phosphorus oxychloride was stirred, while being protected from exposure to atmospheric moisture, at room temperature for 5.75 hours. Isolation of the product as described in the procedure of Example X afforded 230 mg of a mixture, shown by proton NMR analysis to include the title compound (approximately 45%), unreacted bisacetal (approximately 10%), and unidentified impurities (approximately 45%).
EXAMPLE XVI
Preparation of 1-Chloro-1,2,2-tricyclohexyloxyethane Using Thionyl Chloride to Generate HCl
A mixture of 432 mg (1.02 mmoles) of glyoxal bis(dicyclohexyl acetal) (produced in accordance with Example III) and 0.25 mL (3.4 mmoles) of thionyl chloride (97%), commercially available from Aldrich Chemical Company, Milwaukee, Wis., used without purification) was stirred, while being protected from exposure to atmospheric moisture, at room temperature for 7 hours. Isolation of the product as described in the procedure of Example X afforded 398 mg of a mixture, shown by proton NMR analysis to contain the title compound (approximately 35%), unreacted bisacetal (approximately 20%), and unidentified impurities (approximately 45%).
EXAMPLE XVII
Preparation of 1-Benzoyloxy-1,2,2-triethoxyethane
A mixture of 178 mg (0.905 mmole) of 1-chloro-1,2,2-triethoxyethane (produced in accordance with Example IV) and 206 mg (1.43 mmoles) of sodium benzoate in 3.00 mL of N,N-dimethylformamide, spectrophotometric-grade, commercially available from Aldrich Chemical Co., Milwaukee, Wis., was stirred, while being protected from exposure to atmospheric moisture, at room temperature for 21 hours. The mixture was diluted with 20 mL of 3:1 (volume/volume) ether:methylene chloride; and the organic layer was washed five times with 25 mL portions of I0% aqueous sodium chloride to ensure removal of dimethylformamide. The washed organic layer was subsequently dried over anhydrous sodium sulfate and filtered. Removal of the volatile organic material under reduced pressure afforded 212 mg (83% yield) of the title compound, the identity and purity of which were ascertained by proton NMR analysis [two doublets (J=5.5 Hz), one at δ4.63 (CH 3 CH 2 OCHOCH 2 CH 3 ), the other at δ6.07 (CHOC(═O)C 6 H 5 )]. The title compound was subsequently saponified by use of potassium carbonate (2 equivalents) in 4:1 (volume/volume) methanol:water at 0° C. for 5 hours to afford glyoxal mono(diethyl acetal) and the corresponding hydrate (CH 3 CH 2 O) 2 CHCH(OH) 2 and hemiacetal ##STR10## in high yield. Heating the latter mixture in toluene as described in Example XVIII affords glyoxal mono(diethyl acetal) as methanol and water are distilled out of the mixture.
A similar substitution reaction was effected using sodium acetate (in lieu of sodium benzoate) and 1-chloro-1,2,2-triethoxyethane in polar aprotic solvents such as 1-methyl-2-pyrrolidinone or dimethylformamide.
EXAMPLE XVIII
Preparation of Glyoxal Mono(Dibutyl Acetal)
A mixture of 122 mg (0.43 mmole) of 1-chloro-1,2,2-tributoxyethane (produced in accordance with Example V) and 120 mg (1.4 mmoles) of sodium bicarbonate in 2.25 mL of 8:1 (volume/volume) dimethylformamide:water was stirred at 0° C. for 2 hours. Isolation of the product as described in the procedure of Example XVII afforded 108 mg of crude glyoxal mono(dibutyl acetal), shown by spectroscopic analysis to contain a substantial amount of the corresponding hydrate (CH 3 CH 2 CH 2 CH 2 O) 2 CHCH(OH) 2 . In order to obtain the pure monoacetal derivative of glyoxal, this crude product was mixed with approximately 8 mL of toluene, followed by distillative removal (atmospheric pressure) of toluene, water, and trace amounts of 1-butanol over a period of 15 minutes until the volume of remaining solution was approximately 1 mL. Removal of residual toluene at reduced pressure afforded 77 mg (94% yield) of the named monoacetal derivative of glyoxal, whose IR and proton NMR spectral properties were consistent with those previously reported for the analogous glyoxal mono(diethyl acetal). The proton NMR of the named monoacetal exhibited doublets (J=2 Hz) at δ9.51 (aldehydic proton) and 4.55 (CHCHO). For spectral properties of glyoxal mono(diethyl acetal) (2,2-diethoxyacetaldehyde), see: H. J. Bestmann and P. Ermann, Chem. Ber., 116:3264 (1983).
If one desires to prepare this monoacetal on an industrial scale, it would probably be more convenient to conduct the chlorination step (Example V), followed by this hydrolysis step, in a "one-pot" process, avoiding the need for isolating the intermediate alpha-chloro ether.
EXAMPLE XIX
Preparation of N Benzyl-2,2-diethoxyethanimine
A mixture of 158 mg (0.80 mmole) of 1-chloro-1,2,2-triethoxyethane (produced in accordance with Example IV), 0.10 mL (0.92 mmole) of benzylamine, and 136 mg (0.985 mmole) of anhydrous potassium carbonate in 1.00 mL of dimethylform-amide, spectrophotometric-grade, commercially available from Aldrich Chemical Co., Milwaukee, Wis., was stirred, while being protected from atmospheric moisture, at 0° C. for 45 minutes. Isolation of the product as described in the procedure of Example XVII afforded 146 mg (82% yield) of the title compound, whose IR and proton NMR spectral properties were consistent with the assigned structure. This transformation should prove to be quite useful for an industrial-scale synthesis of isoquinoline, previously prepared in high yield by treatment of the named imine with aqueous acid. Unfortunately, the reported preparation of this imine required using glyoxal monoacetal derivatives which are susceptible to polymerization and therefore not easily purified. See: E. Schlittler and J. Muller, Helv. Chim. Acta, 31:914 (1948).
The foregoing examples were provided to further illustrate various embodiments of the invention and other variations and embodiments of the examples will be readily apparent to one of ordinary skill in the art. These examples should not be used to limit the scope of this invention as is set forth in the following claims.
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This invention provides glyoxal derivatives and a method for making these derivatives. A particularly useful derivative, 1-chloro-1,2,2-trialkoxyethane, and a facile method for making these alpha-halo ethers are provided. The alpha-halo ethers are valuable intermediates in the manufacture of a variety of commercial compounds.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to storage area networks.
2. Description of the Related Art
Storage area networks (SANs) are becoming extremely large. Some of the drivers behind this increase in size include server virtualization and mobility. With the advent of virtualized machines (VMs), the number of connected virtual host devices has increased dramatically, to the point of reaching scaling limits of the SAN. Classically Fibre Channel fabrics are limited in the number of domains, usually synonymous with switches, that can exist in the fabric, due to both addressing issues and stability issues. Fibre Channel routers were developed as a way to allow the overall SAN to grow larger without having to reach scale limits of any individual fabric.
The operation of the Fiber Channel routers is generally defined in various Fibre Channel specifications, such as FC-IFR, Rev. 1.06, dated May 12, 2010; FC-FS-3, Rev. 1.11, dated Oct. 22, 2010; FC-SW-5, Rev. 8.0, dated Nov. 22, 2006 and FC-LS-2, Rev. 2.00, dated Jun. 26, 2008, all from T11 and all incorporated herein by reference. A portion of the operations includes determining the various proxy devices for each fabric. This has been done through the use of a special logical storage area network (LSAN) tag present in zone names. The zone has a name starting with “LSAN” and includes the identifiers, preferably worldwide names (WWNs) of the devices in the zone. These zones are defined in the fabric where each device is attached. The LSAN zone entries for all of the edge fabrics in the SAN are obtained and reviewed for matching device entries. When a match is found, the device from the other fabric is imported and presented as a proxy device. For a more detailed description, please refer U.S. Pat. No. 7,936,769, hereby incorporated by reference.
While this method of determining devices to be proxied is effective, as the SAN grows larger and more edge fabrics and devices are included, the amount of storage required by numerous LSAN zones becomes a factor in scaling the SAN as every router maintains the entire LSAN zone list. Therefore the method of determining devices to proxy or present in the edge fabrics is limiting SAN scale.
SUMMARY OF THE INVENTION
In a Fibre Channel SAN and its included routers according to the present invention, each router contains only the LSAN zones that contain devices attached to edge fabrics which are connected to the router. LSAN zone entries include the fabric ID (FID) of each device in addition to the WWN. When a router obtains a new zone database for a newly connected or changed fabric, the router scans the LSAN zone entries for fabric IDs matching a fabric connected to the router and stores those entries. All other LSAN zone entries are not stored. In this manner the size of the relevant tables are reduced, which allows for greater expansion of the SAN as a whole.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention has other advantages and features which will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates an exemplary network according to the prior art.
FIG. 2 is a flow chart of operations of the routers of FIG. 1 according to the prior art.
FIG. 3 illustrates the exemplary network of FIG. 1 as changed according to the present invention.
FIG. 4 is a flow chart of operations of routers of FIG. 3 according to the present invention.
FIG. 5 illustrates a block diagram of an exemplary router according to the present invention.
DETAILED DESCRIPTION
Referring now to FIG. 1 , an exemplary network wo is illustrated. This network wo is used to illustrate both the prior art and an embodiment according to the present invention. Three Fibre Channel routers (FCRs) 102 , 104 , 106 are illustrated as being in a backbone fabric 108 . FCR 1 102 is connected to FCR 2 104 and an edge fabric 12 110 . FCR 2 104 is connected to an edge fabric 3 112 and FCR 3 106 . FCR 3 106 is connected to an edge fabric 4 114 and to edge fabric 12 110 . Two hosts 116 and 118 are connected to edge fabric 12 110 . A storage device 120 is connected to edge fabric 3 112 and a storage device 122 is connected to edge fabric 4 114 . A host 128 is connected to edge fabric 3 112 . A storage device 130 is connected to edge fabric 4 114 . Host 118 and storage device 122 are in LSAN 1 124 , while host 116 and storage device 120 are in LSAN 2 126 . Host 128 and storage device 130 are in LSAN 3 132 .
Shown below the backbone 108 is a chart of the LSAN zone entries in each FCR. As background, LSAN entry is made in a fabric as follows. For fabric 3 112 , the commands at the command line interface (CLI) are:
zonecreate “lsan_zone_fabric 3 _ 12 ”, “10:00:00:00:c9:2b:c9:oc; 50:05:07:61:00:5b:62:ed; 50:05:07:61:00:49:20:b4” where 10:00:00:00:c9:2b:c9:oc is the WWN of FCR 2 104
50:05:07:61:00:5b:62:ed is the WWN of host 116 50:05:07:61:00:49:20:b4 is the WWN of storage device 120 for LSAN 2 124
zonecreate “lsan_zone_fabric 3 _ 4 ”, “10:00:00:00:c9:2b:c9:oc; 50:05:07:61:00:5b:62:ai; 50:05:07:61:00:49:20:cc” where 10:00:00:00:c9:2b:c9:oc is the WWN of FCR 2 104
50:05:07:61:00:5b:62:a1 is the WWN of host 128 50:05:07:61:00:49:20:cc is the WWN of storage device 130 for LSAN 3 130
In fabric 12 110 no the commands are:
zonecreate “lsan_zone_fabric 12 _ 3 ”, “10:00:00:00:c9:2b:c9:11; 50:05:07:61:00:5b:62:ed; 50:05:07:61:00:49:20:b4” where 10:00:00:00:c9:2b:c9:11 is the WWN of FCR 1 102
50:05:07:61:00:5b:62:ed is the WWN of host 116 50:05:07:61:00:49:20:b4 is the WWN of storage device 120 for LSAN 2 124
zonecreate “lsan_zone_fabric 12 _ 4 ”, “10:00:00:00:c9:2b:c9:11; 50:05:07:61:00:5b:62:77; 50:05:07:61:00:49:20:88” where 10:00:00:00:c9:2b:c9:11 is the WWN of FCR 1 102
50:05:07:61:00:5b:62:77 is the WWN of host 118 50:05:07:61:00:49:20:88 is the WWN of storage device 122 for LSAN 1 126
In fabric 4 114 the commands are:
zonecreate “lsan_zone_fabric 4 _ 3 ”, “10:00:00:00:c9:2b:c9:22; 50:05:07:61:00:5b:62:a1; 50:05:07:61:00:49:20:cc ” where 10:00:00:00:c9:2b:c9:22 is the WWN of FCR 3 106
50:05:07:61:00:5b:62:a1 is the WWN of host 128 50:05:07:61:00:49:20:cc is the WWN of storage device 130 for LSAN 3 132
zonecreate “lsan_zone_fabric 4 _ 12 ”, “10:00:00:00:c9:2b:c9:22; 50:05:07:61:00:5b:62:77; 50:05:07:61:00:49:20:88” where 10:00:00:00:c9:2b:c9:22 is the WWN of FCR 3 106
50:05:07:61:00:5b:62:77 is the WWN of host 118 50:05:07:61:00:49:20:88 is the WWN of storage device 122 for LSAN 1 126
For ease of reference, in the table in FIG. 1 and for the rest of this description the device names will be used instead of the WWNs.
FIG. 2 is the flowchart of LSAN zone entry development according to the prior art. In step 200 a router is connected to an edge fabric or the edge fabric zone database is update. In step 202 all of the LSAN zone entries in the edge fabric zone database are imported into the router. In step 204 the LSAN zone entries are scanned and when a match is found with another LSAN zone entry, the indicated remote devices are imported into the newly connected fabric. In step 206 the router is connected to a backbone fabric containing other routers. In step 208 the LSAN entries from all of the other routers are imported into the router, these LSAN entries being from remote fabrics. Step 204 is then performed to import devices.
In the example network of FIG. 1 and the LSAN zone entries provided above, the resulting LSAN zone table in each of the FCRs in FIG. 1 is:
LSAN_ZONE_Fabric12_4, host 118, storage 120
LSAN_ZONE_Fabric12_3, host 116, storage 114
LSAN_ZONE_Fabric3_12, storage 114, host 116
LSAN_ZONE_Fabric3_4, host 128, storage 130
LSAN_ZONE_Fabric4_3, storage 130, host 128
LSAN_ZONE_Fabric4_12, storage 120, host 118
It is noted that FCR 1 102 is not connected to fabric 3 112 or fabric 4 114 and therefore only LSAN zone entries relating to fabric 12 110 are relevant to FCR 1 102 . Thus FCR 1 102 contains the fourth and fifth entries above but has no use for them. Similarly FCR 2 104 has no use for the first and sixth entries but they still exist in the FCR 2 104 LSAN zone entry table. However, FCR 3 106 needs all six LSAN zone entries as it is connected to both fabric 12 110 and fabric 4 114 and so needs all three LSANs.
While this simple example shows a few extra LSAN zone entries, it is remembered that this is a very simple SAN provided for explanatory purposes and a normal SAN where the LSAN zone entry table space is limiting the size of the SAN there are thousands of such entries and a great majority of them are not necessary in any given FCR.
FIG. 3 is the network wo of FIG. 1 except that embodiments according to the present invention are utilized. In the preferred embodiment the LSAN zone entries are modified from the prior art to include a fabric ID (FID) with each node device in the entry. For fabric 3 112 , the commands at the command line interface (CLI) are:
zonecreate “lsan_zone_fabric 3 _ 12 ”, “FCR 2 104 ; host 116 ; 12 ; storage device 120 ; 3 ”
for LSAN 2 124
zonecreate “lsan_zone_fabric 3 _ 4 ”, “FCR 2 104 ; host 118 ; 3 ; storage device 130 ; 4 ”
for LSAN 3 130
In fabric 12 110 the commands are:
zonecreate “lsan_zone_fabric 12 _ 3 ”, “FCR 1 102 ; host 116 ; 12 ; storage device 120 ; 3 ”
for LSAN 2 124
zonecreate “lsan_zone_fabric 12 _ 4 ”, “FCR 1 102 ; host 118 ; 12 ; storage device 120 ; 4 ”
for LSAN 1 126
In fabric 4 114 the commands are:
zonecreate “lsan_zone_fabric 4 _ 3 ”, “FCR 3 106 ; host 118 ; 3 ; storage device 130 ; 4 ”
for LSAN 3 132
zonecreate “lsan_zone_fabric 4 _ 12 ”, “FCR 3 106 ; host 118 ; 12 ; storage device 120 ; 4 ”
for LSAN 1 126
As can be seen, each node device, such as a host or storage device, has its identification followed by an FID value.
Operation of each FCR of the preferred embodiment is illustrated in FIG. 4 . In step 400 a router is connected to an edge fabric or the edge fabric zone database is update. In step 402 all of the LSAN zone entries in the edge fabric zone database are imported into the router if the LSAN zone entry includes an FID that matches the FID of a fabric the router is connected to. In step 404 the LSAN zone entries are scanned and when a match is found with another LSAN zone entry, the indicated remote devices are imported into the newly connected fabric. In step 406 the router is connected to a backbone fabric containing other routers. In step 408 the LSAN entries from all of the other routers are imported into the router if the LSAN zone entry includes an FID that matches the FID of a fabric the router is connected to. Step 404 is then performed to import devices. Thus LSAN zone entries are filtered at import time to import only those having devices connected to a fabric connected to the router. Thus the LSAN zone entries discussed above as not needed for FCR 1 102 and FCR 2 104 are not present.
In the example network of FIG. 3 and the LSAN zone entries provided above, the resulting LSAN zone tables in the FCRs in FIG. 3 are:
For FCR 1 102 :
LSAN_ZONE_Fabric12_4, host 118, FID12, storage 120, FID4
LSAN_ZONE_Fabric12_3, host 116, FID12, storage 114, FID3
LSAN_ZONE_Fabric3_12, storage 114, FID3, host 116, FID12
LSAN_ZONE_Fabric4_12, storage 120, FID4, host 118, FID12
For FCR 2 104 :
LSAN_ZONE_Fabric12_3, host 116, FID12, storage 114, FID3
LSAN_ZONE_Fabric3_12, storage 114, FID3, host 116, FID12
LSAN_ZONE_Fabric3_4, host 128, FID3, storage 130, FID4
LSAN_ZONE_Fabric4_3, storage 130, FID4, host 128, FID3
For FCR 3 106 :
LSAN_ZONE_Fabric12_4, host 118, FID12, storage 120, FID4
LSAN_ZONE_Fabric12_3, host 116, FID12, storage 114, FID3
LSAN_ZONE_Fabric3_12, storage 114, FID3, host 116, FID12
LSAN_ZONE_Fabric3_4, host 128, FID3, storage 130, FID4
LSAN_ZONE_Fabric4_3, storage 130, FID4, host 128, FID3
LSAN_ZONE_Fabric4_12, storage 120, FID4, host 118, FID12
FCR 1 102 imports storage unit 120 and storage unit 122 into fabric 12 110 , those storage units 120 and 122 appearing as proxy storage units in fabric 12 110 . Similarly FCR 2 104 imports host 116 and storage unit 130 into fabric 3 112 while FCR 3 106 imports hosts 118 and 128 into fabric 4 114 . Further, FCR 3 106 would negotiate with FCR 1 102 and import storage unit 122 into fabric 12 110 rather than having FCR 1 102 do the import mentioned above as the path from fabric 12 110 to storage unit 122 is shorter using FCR 3 106 as compared to using FCR 1 102 as the backbone fabric 108 hops are not required.
Therefore each FCR includes only the LSAN zone entries where a node is connected to one of the fabrics connected to the FCR. As discussed above, in a normal SAN where the size of the LSAN zone entry table would be limiting the SAN size according to the prior art, in embodiments according to the present invention an increased number of devices can be added to the SAN.
FIG. 5 is a block diagram of an exemplary switch 598 . A control processor 590 is connected to a switch ASIC 595 . The switch ASIC 595 is connected to media interfaces 580 which are connected to ports 582 . Generally the control processor 590 configures the switch ASIC 595 and handles higher level switch 507 operations, such as the name server, routing table setup, and the like. The switch ASIC 595 handles general high speed inline or in-band operations, such as switching, routing and frame translation. The control processor 590 is connected to flash memory 565 or the like to hold the software and programs for the higher level switch operations and initialization such as performed in FIGS. 2 and 4 ; to random access memory (RAM) 570 for working memory, such as the name server and route tables; and to an Ethernet PHY 585 and serial interface 575 for out-of-band management.
The switch ASIC 595 has four basic modules, port groups 535 , a frame data storage system 530 , a control subsystem 525 and a system interface 540 . The port groups 535 perform the lowest level of packet transmission and reception. Generally, frames are received from a media interface 580 and provided to the frame data storage system 530 . Further, frames are received from the frame data storage system 530 and provided to the media interface 580 for transmission out of port 582 . The frame data storage system 530 includes a set of transmit/receive FIFOs 532 , which interface with the port groups 535 , and a frame memory 534 , which stores the received frames and frames to be transmitted. The frame data storage system 530 provides initial portions of each frame, typically the frame header and a payload header for FCP frames, to the control subsystem 525 . The control subsystem 525 has the translate 526 , router 527 , filter 528 and queuing 529 blocks. The translate block 526 examines the frame header and performs any necessary address translations, such as those that happen when a frame is redirected as described herein. There can be various embodiments of the translation block 526 , with examples of translation operation provided in U.S. Pat. No. 7,752,361 and U.S. Pat. No. 7,120,728, both of which are incorporated herein by reference in their entirety. Those examples also provide examples of the control/data path splitting of operations. The router block 527 examines the frame header and selects the desired output port for the frame. The filter block 528 examines the frame header, and the payload header in some cases, to determine if the frame should be transmitted. In the preferred embodiment of the present invention, hard zoning is accomplished using the filter block 528 . The queuing block 529 schedules the frames for transmission based on various factors including quality of service, priority and the like.
Certain embodiments provide additional checking of the LSAN zone entries to limit the chance of errors, and thus improper importation of devices. In a first of these embodiments, each router includes or has access to a database containing all of the nodes connected to the all fabrics the router is connected to, the database including device WWN and FID. Upon determining that an LSAN zone entry includes a device connected to a fabric connected to the router, the router can then check the device WWN and FID against the database to cross check the values. If a mismatch is detected, the router can provide an error indication to the administrator and not import that LSAN zone entry. If the error is not in the local device but the device connected to the remote fabric, the router connected to the remote fabric will detect the mismatch and provide the error indication.
In an alternate embodiment, the router includes or has access to a database containing all of the nodes connected to the all fabrics the router is connected to, the database including device WWN and FID. In this alternate embodiment the LSAN zone entries do not include FID values for each device but rather the router compares device WWN values in the LSAN zone entries against the directly connected device database and confirms connection to a directly connected edge fabric by use of the FID value in the database. If the database FID indicates a match to a connected edge fabric, the LSAN zone entry is imported with an indication of the proper edge fabric FID to allow proper device importation. This alternative allows use of current LSAN zone entries but requires the development and maintenance of the device database.
In an alternate embodiment administrative management software, such as Brocade Network Advisor, is operating on the SAN. The management software can maintain this database of all connected devices, and often does. The management software can then periodically request the LSAN zone entries from the various routers and switches in each fabric and compare all of the LSAN entries against the database to determine either WWN or FID errors. The management software could then provide the error indication and also provide any corrected entries to the various switches and routers. In yet another embodiment the management software could be the primary repository of the entire LSAN zone entry table, all entries, and then could provide that to the router on request, rather than the router obtaining the entries from the connected fabrics and other routers.
By providing the fabric ID of devices that are to be in an LSAN to the LSAN zone entry, each router can scan the LSAN zone entries and import only those that have devices in a fabric connected to the router. Extraneous LSAN zone entries are not present, allowing additional devices to be added to the SAN.
The above description is illustrative and not restrictive. Many variations of the invention will become apparent to those skilled in the art upon review of this disclosure. The scope of the invention should therefore be determined not with reference to the above description, but instead with reference to the appended claims along with their full scope of equivalents.
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In a Fiber Channel SAN and its included routers, each router contains only the LSAN zones that contain devices attached to edge fabrics which are connected to the router. LSAN zone entries include the fabric ID (FID) of each device in addition to the WWN. When a router obtains a new zone database for a newly connected or changed fabric, the router scans the LSAN zone entries for fabric IDs matching a fabric connected to the router and stores those entries. All other LSAN zone entries are not stored. In this manner the size of the relevant tables are reduced, which allows for greater expansion of the SAN as a whole.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to electron processing. There are many embodiments of the use of energetic electrons for the modification or treatment of matter. Of particular interest for the process taught here is the surface modification or sterilization of matter. For a solid object, this might require penetration of only a few microns below the surface, typically well beyond the surface connected pore structure of the hydrocarbon for sterilization or surface modification if a polymer is the material of interest.
Treatment requirements are determined by the energy investment per unit mass of the product required to accomplish the desired effect. This is usually stated in units of joules/kg using the International Unit of absorbed dose: namely, the Gray, which is 100 rads or 1 joule/kg. Most electron "initiated" processes require 1-50 kGy of treatment (0.1-5 Megarads). Depending upon the electron energy used and hence, depth of penetration, this treatment level or dose can be related directly to the electron fluence (flux×time) in electrons/cm 2 received by the surface of the product. For example, at low energies, 10 kGy or 1 Megarad of dose will be delivered by an electron surface fluence of one microcoulomb/cm 2 of surface area.
The technique taught here is that of providing a uniform and predictable fluence around a dynamic object with a unilaterally directed electron beam. In fact, the electron processor system is usually controlled on the basis of its known (measured) delivery efficiency or yield, usually quoted as a machine constant k in units of kiloGray meters/min./ma. Once this figure of merit is known for a processor geometry, the dose delivered D can be calculated with a knowledge of the product velocity v while in the processor and of the machine current I, where D=kI/v.
The transit velocity of the product in the processor is typically controlled by a supporting mechanical conveyor or by the transport velocity of the product itself, if it is film or web for example.
2. Description of the Related Art
One of the prerequisites of aseptic or sterile processing is that all surfaces exposed to the sterile environment must be bioburden free. For example, in the sterile packaging of foodstuffs or medical products into open mouthed containers, it is essential that not only the product contact surfaces be sterile, but that the non-contact surfaces of the container be sterile so that no contamination can reach those ultimately sealed-off surfaces of the container through convective mixing, contamination through contact, etc.
Any sterilizing agent, such as the low energy electrons, can easily be blocked from a container surface by thin grippers, belts or planchets with which it may be in contact. As a result, some dynamic manipulation of the container may be required to assure treatment of "occluded" areas of the surface, a procedure difficult to implement in high speed processes. An alternative approach is bilateral treatment either simultaneous or sequential, which is usually impracticable..
The geometry taught here greatly simplifies the uniform treatment of three dimensional devices with energetic electrons through the use of contactless presentation of the product to the flux of energy available in the electron stream. In principle, contactless presentation of an object to the electron beam can be accomplished by suspension and translation of the device in an air stream. However, access to all surfaces by the electrons is difficult to achieve, particularly with a unilateral source, in that sufficient separation of the product from the surrounding walls must be achieved to permit electron access to the surfaces, particularly those on opposite sides of the object to those surfaces directly illuminated. In addition, the control of a product in pneumatic transport is difficult for the contoured, molded surfaces in the objects of interest. Precise control of residence time in the electron beam is mandatory for process quality assurance and must rely upon a "fail:safe" transport technique, especially for "regulated" processes such as sterilization. Other techniques of product support such as magnetic levitation are too complex and generally totally ineffective for the nonmagnetic polymers of primary interest for either electron surface modification or sterilization.
Supporting devices which could provide product orientation in the electron beam so that "all" surfaces receive comparable fluence of energy during transit through the beam or during static "start:stop" exposure, are too difficult to implement. The major difficulty is in time of exposure, in that residence times in the beam for most practical industrial applications are less than one second, so that the controlled manipulation of the product with robotics during transit, in times of a few hundred milliseconds, becomes impractical.
Some sterilizing agents such as gamma-rays, x-rays or very high energy electrons, can provide full penetration of a container or of a molded component such as a cap, or an exit or entry fitment on a bag for sterile products, such as a wedge or needle port. Unfortunately, these energy sources are usually very large and vault shielded, so that it is impractical to incorporate them into the aseptic container manufacturing and/or filling system. In practice, these components are sterilized in biobarrier bags at a central facility and the sealed bags taken to the manufacturing/filling machine. There they must be introduced to the machine by entrance through a sterile port which permits handling of the pre-sterilized components under aseptic conditions. This is a difficult procedure and usually involves a chemically sterilized adaptation port and very complex handling procedures with performance difficult to verify.
SUMMARY OF THE INVENTION
An electron beam irradiation geometry is taught which provides a uniform, isotropic irradiation of components which are to be sterilized or bulk/surface modified using energetic electron sources. In principle, the technique uses a side fired beam directed into a radiation cavity whose longitudinal axis of symmetry is oriented along the earth's gravitational vector, i.e. is vertical. In operation, the products are individually dropped into the "hohlraum", now filled with energetic electrons, and the average product velocity under free-fall can be matched to the dose rate in the cavity so that the product of dose rate and exposure time in the cavity will provide the necessary treatment of the product. Product entrance and exit velocities are controlled by the ballistics (free-fall distance) of the product into the irradiation chamber or cavity. The product is untouched (mechanically) during irradiation permitting uniform treatment of small or large products of complicated geometries which would otherwise require impractically complex handling in order to ensure complete surface treatment (e.g. as in the sterilization application). This problem arises from the limited penetration capability of electrons at the energies of interest; e.g. only a few hundred microns of material,--thicknesses which are typical of the grippers used to manipulate such low mass products.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may best be understood from the following detailed description thereof, having reference to the accompanying drawings, in which:
FIG. 1 is a diagram showing the geometry of "contactless" sterilization technique in accordance with the invention;
FIG. 2 is a graph showing terminal velocity vs. free-fall distance;
FIG. 3 is a graph showing average velocity and dwell time for a free-fall system with an exposure field of 10 cm. as a function of free-fall distance;
FIG. 4 is a graph showing calculated delivered dose at 400 kV as a function of free-fall distance at beam currents of 1 and 2 ma and an area of 50 cm 2 ;
FIG. 5 is a vertical section of a cavity design for free-fall treatment in accordance with the invention;
FIG. 6 is a schematic of the configuration used in experimental geometry for electron fluence flattening demonstration;
FIG. 7 is a graph showing electron number reflection ratio as a function of incident electron energy; and
FIG. 8 is a graph showing electron energy reflection ratio as a function of incident electron energy.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Contactless Device Transport in the Cavity
The ballistic transport of a product, for example powders and particulate matter, is rarely used in electron processing because the velocities achievable are of little interest for mass transport where high throughput is essential to attractive process economics. This is no longer a problem with product sterilization, particularly for in-line treatment of package fitments of discrete three dimensional products. Here process rates of a few per second are typical so that elevated process speeds are unnecessary.
The principles of product handling are illustrated in FIG. 1 and show the fitment or product F transported by conveyor C to the mouth of the hohlraum cavity H, typically cylindrical, illuminated with energetic electrons passing through window W from accelerator A. This window may be illuminated from a scanner S 1 and horn H 1 , or it may be illuminated directly by a curtain type, pulsed or d.c. electron processor. The free-fall distance from the end of conveyor C to the cavity entrance will determine the entrance velocity v, of the product while in free-fall, and the exit velocity will be determined by the cavity length D. Convoluted transport of the product from C to the cavity entrance may be used to simplify radiation shielding, while the same technique can be employed at the exit of cavity H.
A laminar flow of nitrogen injected through the cavity walls may be used to maintain product motion near the longitudinal symmetry axis of the cavity. Coolant pipes P may be used if required, to dissipate the electron beam energy deposited in the reflective liner L. Continuous monitoring of the electron beam characteristics (energy, dose rate, uniformity) injected into the cavity at window plane W is achieved with a real time radiation monitor, for example of the type described by Nablo, Kneeland and McLaughlin (Nablo, S. V., Kneeland, D. R. and McLaughlin, W. L., "Real Time Monitoring of Electron Processors", Jour. Rad. Phys. Chem. 44 (1995)). It is also practicable to elevate the product's residence time in the treatment zone or cavity with the use of a counterstreaming (vertical) flow of nitrogen or air to reduce the free-fall acceleration and average transit velocity of the product.
From this point the product is carried on conveyor C 1 , by means of planchets P 1 if necessary, to manipulator M or whatever next step is involved in the fabrication of the product. Typical devices of interest for this type of in-line sterilization are a few cc in volume and a few grams in weight, so that estimates of velocity in free-fall ignoring air drag will be sufficiently accurate to illustrate the principles of the technique taught here.
In FIG. 2, the simple entrance velocity v, of a product is shown as a function of free-fall distance B. It is evident that convenient transport velocities of the order of 1 meter/second are available for convenient distances; e.g. 5 cm in earth's gravitational field. Estimates can now be made of system performance for various cavity geometries, but a D (cavity length) value of 10 cm is assumed for purposes of illustration. In this instance, a uniform electron beam procesor window illumination of 5 cm width×10 cm length is assumed, adapted to an 8-10 cm diameter cavity.
In FIG. 3, data are shown for the cavity system based upon an effective treatment zone of 10 cm along its longitudinal axis. Curve A shows the average velocity of the product in the cavity as a function of free-fall distance B prior to entrance. Curve B shows the dwell time of the product in the 10 cm cavity as a function of free-fall distance B.
Based upon an accelerator voltage of 400 kilovolts, it is now possible to calculate the surface dose delivered during free-fall of the product through hohlraum H as a function of entrance velocity; i.e. free-fall distance B. Two operating points are assumed in the data of FIG. 4, one at a beam power of 400 watts (1 ma or 20 μa/cm 2 at the window), and a second at a beam power of 800 watts (2 ma or 40 μa/cm 2 at the window). Even at the lower power level, doses in the 1.5 to 2.0 Megarad range are possible at small distances B, and such doses are typical of those required for the product processes of interest. For example, for discrete products to be sterilized with an assurance level of 10 -6 , the requisite doses are specified by the AAMI guidelines (ANSI/AAMI St 31-1990) (Guideline for Electron Beam Radiation Sterilization of Medical Devices, ANSI/AAMI St. 31-1990, Association for the Advancement of Medical Instrumentation, 3330 Washington Boulevard, Suite 400, Arlington, Va. 22201-4598). This treatment or sterilization dose depends upon the average bioburden carried by the product. These surface contamination levels are typically a few colony forming units per device. For example, these guidelines specify 1.52 Megarads for a bioburden of 2 colony forming units per device, and 2.01 Megarads for a bioburden of 50 c.f.u.
Treatment Cavity Design
Using the reflective surface properties reviewed hereinafter, it becomes possible to design a cavity geometry in which the energy (electron beam) is injected radially at one point, and as a result of multiple scattering, the cavity is filled with an isotropic flux of electrons which will suffer several reflections on the average before total absorption. The design of the cavity may reflect the requirements (geometry) of the product passing through it so that the "hohlraum" is most effective for uniform illumination of the product. In view of the relatively large half angles of scatter of the primary electrons in the metallic (usually Titanium) windows used to terminate the vacuum section of the electron processor from the atmospheric environment in which the product moves, the electron beam can be controlled to provide improved product illumination uniformity. For example, with the 10 cm long×15 cm diameter cavity discussed in the following paragraphs, a cooled beam stop can be used to reduce the direct illumination of the front surface of the product passing through it so that the front:rear fluence ratio is reduced. A more convenient approach is to apply a predetermined beam scan raster so that the center to edge current density at the window is tailored to provide a better circumferential fluence distribution around the product. Although circumferential uniformity of a treated product is important, rather large variations are normally tolerable (×2) as long as minimum levels are achieved.
In the schematic representation of FIG. 5, the cavity walls are water cooled to provide dissipation of the energy not absorbed by the product and delivered to the cavity surfaces. Tantalum has been used in the studies conducted in developing this concept, although other high Z metals such as those of the platinum group (Z=75-79) are well suited to this application.
One of the advantageous features of this cavity design is the ability to trap most of the penetrating x-rays and bremsstrahlung generated by the beam as electrons stop in the cavity walls or in the product.
At elevated energies, these can be significant. For example, in Tantalum the radiation yields; i.e. energy loss in the form of bremsstrahlung, at electron energies of 0.1 and 0.5 Mev are 0.014 and 0.047 respectively, while in polyethylene they are 0.0005 and 0.002 respectively. For very compact pulsed systems, shielding shutters may be used to close off the cavity at planes AA 1 , and BB 1 during treatment and, hence, during the periods of electron illumination and x-ray production in the cavity (see FIG. 5).
The nature of the cavity leads to relatively stagnant air in its interior, especially if closed to convection at the top, so that any Ozone formed there is rapidly recombined at the elevated temperature of 200°-300° C. experienced inside the cavity even with modest beam powers. As a result, the need for inerting of the cavity with Nitrogen flushing, for example, is eliminated except in those instances where Ozone dragged by the product into the region around the cavity poses problems.
In a preferred embodiment of the invention, the energies of the electrons are limited to less than 600 keV so that efficient electron reflection from cavity walls can be realized in a self-shielded geometry--that is, where sufficient high atomic number shielding clad to the apparatus will provide adequate radiation attenuation to permit "unrestricted" operation; i.e. operation where no exclusion area or access restriction for reasons of operator safety, are required.
Various means for adjusting non-uniform illumination of the cavity walls so as to improve the peripheral uniformity of treatment of the object passed through the cavity may be used without departing from the spirit and scope of the invention; for example, such means include stops, magnetic shaping, cooled apertures, parallel beams and programmed scanning, among others.
The treatment cavity forms a treatment zone into which high-energy electrons are directed; it is lined with high atomic number material such as tantalum, gold or uranium so that good isotropy of electron direction results in the treatment zone, for example, in a semi-cylindrical or cylindrical cavity. The orientation of the electron filled cavity (treatment zone) is such that the product can be passed through it ballistically or by pneumatically controlled transfer without any direct or occluding contact with the object to be treated, contact which would otherwise prevent electrons from reaching all surfaces of the object.
The preferred dimensions of the treatment zone are as follows. The treatment zone should be a cylindrical cavity having a diameter at least twice that of the solid/molded product, and with an electron window width of the order of one to two times the cavity radius. The cavity length will be determined by the dose requirements of the process but will typically be 1 to 3 cavity diameters, and the free fall distances at entrance and exit, because of shielding requirements, will be 1 to 2 cavity diameters.
Experimental
In order to demonstrate experimentally the flexibility of the high Z lined cavity for this purpose of electron fluence "flattening" over a geometric surface, experiments were conducted on a 225 kilovolt machine which provides monoenergetic electrons from a 5 cm wide×30 cm long window into a deep conveyor. This electron processor is of the Electrocurtain® design manufactured by Energy Sciences Inc., Wilmington, Mass. The system was used so that a semicylindrical cavity, lined with Tantalum, was oriented with its longitudinal axis across the narrow (5 cm) width of the beam. Studies of the transverse distribution of the beam had shown it to possess a full width at half maximum of 8 cm some 5.4 cm from the window, and 11.5 cm at 8.6 cm from the window. The experiments were performed with the opening to the semi-cylindrical cavity some 6.4 cm from the window and with a cavity length of 10 cm, approximately the beam's half maximum value.
Cylindrical objects (polystyrene syringes) were oriented along the cavity axis and two sample diameters were used (1.0 and 1.4 cm) to study the peripheral (circumferential) dose distributions with and without backscatter. Thin radiochromic film (10 μm thick) was wrapped around the syringe barrels and used to determine the dose distributions for each of the irradiation conditions selected. The syringe diameters selected were considered to be representative of the characteristic dimensions of the molded products and devices for which this technique is most appropriate; i.e. diameters of 1-2 cm and lengths of 1-3 cm.
The semi cylinder diameter of 5.0 cm was selected because it presents a width some 3 to 5 times that of the actual product diameter, offering the best opportunity for dose flattening with the backscatter coefficients of 0.35 to 0.40 expected from the data of FIGS. 7 and 8.
A schematic of the configuration used is shown in FIG. 6 and was designed to provide a simulator of the product:cavity:beam geometry for the "free-fall" case taught here, which would use a vertically oriented beam.
As shown in FIG. 6, the cavity access opening 15 of 4.7 cm is located 6.4 cm (distance 16) from window surface of the electron processor whose 15 μm titanium window gives a half angle of scatter 2 of some 30° to the energetic electrons 17 at these energies used (225 keV). The electrons emerge from vacuum region 14 and continue to scatter in the air filled or Nitrogen purged flight path 3 until they reach exemplar 4, beam stop 5 or cavity 6. The 5 cm diameter cavity 6 used here was made of pvc, and could be lined with Ta foil 7 (150 μm thickness). The cavity was fixed on plate 8 for positioning on the static conveyor chain 9. Thin film dosimeters 10 were mapped helically on exemplar 4 to provide at least 3 or 4 full circumferential maps of the surface, with 0° taken as top dead center 11 and 180° as the bottom of the device 12 facing the most occluded region of the cavity wall.
Exemplar 4 could be easily removed for dosimeter mounting or removal, and its longitudinal axis of symmetry 13 was positioned to be that of the cavity 6.
Beam stops 5 consisted of cylindrical rods which were supported at cavity entrance plan AA 1 . Their diameters could be selected to adjust the percentage of the electron flux delivered across access opening 15 which could reach the cavity reflective liner, and to simultaneously adjust the ratios of the "direct" fluence at 0° (11) to the "indirect" fluence at 180° (12).
Some typical data taken with the arrangement of FIG. 6 are shown in table 1. The ratio of doses recorded at 180° (12) to those at 0° (11) are shown in column 5. The addition of the Tantalum backscatter foil doubles the fluences recorded at location 12 from 14% to 30% of those recorded at location 11. The addition of stop 5 is increasingly effective as its diameter is increased from 7 to 35 percent that of the cavity opening width. This arrangement simulates the effect: of such a programmed scan discontinuity in a two dimensional scanned electron beam, of such a physical stop in a continuous curtain beam or, of an electron optically divided distribution in a continuous beam; i.e. parallel divided beams directly illuminating such a cavity with or without stops.
The results of table 1 demonstrate the efficacy of the backscatter, cavity technique for flattening the dose (electron fluence) distribution around solid or convoluted objects. The elevation of these dose ratios to 50% or more is entirely adequate for most electron processing applications. In fact, the 30% figure is adequate without resorting to any injected flux distribution modification in that most processes of interest will accommodate a 3:1 dose ratio variation across the product's surface, as long as the minimum dose levels required by the process are satisfied.
TABLE 1______________________________________Dose Data for the Cavity Geometry Product Cavity BeamRun # Diameter Wall Stop 180°-0° Ratio______________________________________1 1.0 cm pvc None 0.142 1.0 cm Ta None 0.303 1.35 cm pvc None 0.144 1.35 cm Ta None 0.295 1.35 cm Ta 3.5 mm o.d. 0.376 1.35 cm Ta 7.5 mm o.d. 0.457 1.35 cm Ta 12.5 mm o.d. 0.528 1.35 cm Ta 16.5 mm o.d. 0.58______________________________________
Electron Reflection
When energetic electrons impinge on a solid target, a portion of the incoming energy is reflected from the target surface. Most of this energy is carried by electrons whose direction of motion was altered by more than 90° due to multiple scattering of the primary electrons with electrons in the atoms of the target. This reflection coefficient or number of scattered electrons per incident electron is dependent upon electron density in the target, which of course controls the probability of electron-electron scatter. This density varies the atomic number of the target so is very low for the hydrocarbons (primarily H and C) and rises rapidly for the heavier metals. Knowledge of these reflection coefficients is very important in the diagnosis and application of electron beams and both the number reflection ratios η N and energy reflection ratios η E have been studied extensively over a broad range of energies and Z (atomic number) values.
Tabata et al (Tabata, T., Ito, R. and Okabe, S., "An empirical equation for the backscattering coefficient of electrons", Nucl. Instrum. and Methods 94, 509-513, (1971)) summarized the available data from 50 keV to 22 Mev and derived an empirical equation for the derivation of η n . Soum et al (Soum, G., Ahmed, H., Pinna, H. and Verdier, P., "Transmission and backscatter of electrons of high energy", Rev. Phys. App. 20, 823-829, (1985) and Soum, G., Mousselli, A., Arnal, F. and Verdier, P., "Study of the transmission and backscatter of electrons of energy 0.05 to 3 Mev. in the multiple scattering domain", Rev. Phys, App 22, 1189-1209, (1987)) reported new data over the 50 keV to 3 Mev regime of greatest interest for electron processing. More recently, Halbleib et al (Halbleib, J. A., Kensek, R. P., Melhorn, T. A., Valdez, G., Seltzer, S. M. and Berger, M. J., ITS version 3.0; The Integrated TIGER Series of coupled electron/photon Monte Carlo transport codes. Report SAND 91-1634, Sandia Nat. Labs, Albuquerque, N.M.) (1993), used the TIGER Monte-Carlo code to calculate η N and η E over the energy range from 1-10 5 kev, and Tabata et al (Ito, R., Andreo, P. and Tabata, T., "Reflection of Electrons and Photons from Solids Bombarded by 0.1-100 Mev Electrons", Radiat. Phys. Chem. 42, #4-6, 761-764, (1993)) have used a least squares fit to all the experimental data available, including the TIGER code predictions of Halbleib et al, over the Z range from Al (Z=8) to U (Z-92). Results for the electron number reflection ratio η N for the higher Z values are shown in FIG. 7, while the electron energy reflection ratio η E is shown in FIG. 8. Here the reflection ratio is defined as the ratio of the total energy of backscattered electrons to the total incident energy.
It is evident from FIG. 7 that very high reflection coefficients in the 0.45-0.50 range are observed for Z values above 75, and that this performance remains quite flat over the energy range of major interest for electron processing; i.e. 0.01-1.0 Mev. At higher energies, reduction of albedo results from deeper penetration of the primaries and reduced probability of reflected electron escape from or return to the surface of incidence.
A similar behavior is observed in the data of FIG. 8 in that at the energies of immediate interest for sterilization; i.e. 0.1-0.5 Mev., these energy reflection ratios are large and relatively flat. For example, for U, the values vary from 0.44 to 0.40 respectively (or only 10%) and for Au, 0.41 to 0.36 respectively. These data show that the use of a practical electron reflector geometry at these elevated Z values can provide a relatively flat and predictable yield over a broad energy range, e.g.×5, typical of the dynamic range of most modern electron processors.
Having thus described the principles of the invention, together with several illustrative embodiments thereof, it is to be understood that, although specific terms are employed, they are used in a generic and descriptive sense, and not for purposes of limitation, the scope of the invention being set forth in the following claims.
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A compact, selfshielded electron beam processing technique for three dimensional products includes a treatment zone bounded by at least one material of high atomic number. Energetic electrons are directed into the treatment zone in such a manner that electron reflection from the boundary of the treatment zone assists in filling the treatment zone with energetic electrons. The products to be treated are caused to travel through the treatment zone without any mechanical contact therewith (such as by ballistic or pneumatic techniques).
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FIELD OF THE INVENTION
[0001] The invention concerns a process for the production of a preform for an optical fiber for optical data transmission technology, by providing a substrate tube of quartz glass which tube has different dopants in radial progression, by introducing a core glass of synthetic quartz glass, and by surrounding the substrate tube with a jacket tube.
[0002] Furthermore, the invention concerns a substrate tube of quartz glass for the production of a preform for an optical fiber for optical data transmission technology, where the preform comprises a core glass which is surrounded by a mantle region of which region at least a part is provided in form of the substrate tube which tube has different dopants in radial direction.
DISCUSSION OF THE PRIOR ART
[0003] In general, preforms for optical fibers have a core which is surrounded by a cladding of a material which has a lower refractive index. Leading processes for the production of the preform core from synthetic quartz glass are those designated VAD (vapor-phase axial deposition), OVD (outside vapor-phase deposition), MCVD (modified chemical vapor-phase deposition), and PCVD (plasma chemical vapor-phase deposition). In all these processes the core is produced in that SiO 2 particles are deposited on a substrate and vitrified. The deposition of the core in the VAD and OVD processes takes place from the outside onto a substrate; in the MCVD and PCVD processes it takes place on the inside of the so-called substrate tube. The substrate tube may form the optically active cladding or a part of it. Depending on the fiber design the substrate tube is composed of doped or undoped quartz glass. In addition, production of preforms is known according to the so-called rod-and-tube approach where a rod made of a core glass is introduced into a jacket tube and is fused with the latter. Optical fibers are obtained from the preform by elongating it.
[0004] Depending on the process, the cladding glass is produced in a separate process (OVD, MCVD, plasma process, rod-and-tube process) or the cladding glass and the core glass are produced at the same time, as is common in the so-called VAD process. The refraction index differential between core glass and cladding glass is adjusted by adding suitable dopants. It is known that fluorine and boron lower the index of refraction while a plurality of dopants is suitable for the increase of the refractive index, especially germanium, phosphorus and titanium.
[0005] In a simple optical fiber design, the core made of a quartz glass having a first index of refraction is surrounded by a mantle made of a quartz glass having a second, lower index of refraction. However, in the course of optimization of optical fibers, in particular for the simultaneous transmission of several wavelengths and for higher transmission rates, fiber designs are being developed which have substantially more complex refractive index profiles. For example, EP-A1 785,448 describes an optical fiber of quartz glass which has a fiber design called “double-core+double cladding” which is supposed to reduce the so-called polarization-mode dispersion.
[0006] A process for the production of a preform and a substrate tube suitable therefor of the kind described in the beginning are known from EP-A2 434,237. It describes the production of an optical single-mode fiber which is there called the “depressed-clad-type.” The preform for this fiber is produced by internal deposition (MCVD process). For this, an inner-cladding glass layer of fluorine-doped quartz glass is first deposited on the inner wall of a substrate tube, followed by a core glass layer of Ge-doped quartz glass. The quartz glass substrate tube used there may have areas of varying levels of fluorine doping across the thickness of its wall. The tube thus coated on the inside is collapsed, and is subsequently surrounded with a so-called “jacket tube” made of a jacket glass, forming a preform.
[0007] Even though production of dispersion-shifted or so-called dispersion-compensating optical fibers is possible by means of the known process, it would be necessary to build up a plurality of internal layers in the known substrate tube.
[0008] In the course of the MCVD deposition the increasing number of layers and their thickness leads to a corresponding decrease of the inside diameter of the substrate tube and with it to a reduction of the inner surface. Therefore the effectiveness of the deposition decreases during the progress of the process. This can be counteracted only to a limited degree by increasing the inner diameter because the temperature necessary for the deposition is usually created by external heating. However, an increase of the inner diameter or wall thickness of the substrate tube requires an increase of the external temperature in order to maintain the deposition conditions on the inside of the substrate tube. But this is limited due to the softening and the plastic deformation of the substrate tube. Moreover, the collapsing becomes increasingly difficult with thick-walled or large substrate tubes and with thick inner layers.
SUMMARY OF THE INVENTION
[0009] Therefore the object of the invention is to provide an effective and economical process for the production of a preform whereby complex refractive index profiles may be produced in a highly productive manner, and to provide a substrate tube suitable therefor, in which substrate tube less core glass material is needed, either for the internal deposition process or for the core glass rod in the rod-in-tube process.
[0010] As concerns the process the object is accomplished on the basis of the process described in the beginning in that a substrate tube is used which is obtained by the vitrification of a tube-shaped porous SiO 2 blank which is provided with a core glass layer, the latter having been produced by adding, before the vitrification, to a first radial portion of the SiO 2 blank a first dopant which increases the refractive index of quartz glass.
[0011] The substrate tube used for the process comprises a core glass layer. By this is meant a radial portion of the entire wall thickness of the substrate tube, a generally cylindrical portion with, i.e., an annular cross-section that has a thickness that extends in the radially outward direction of the substrate tube, which portion contains a dopant which increases the refractive index of quartz glass. Such dopants contain for example germanium, phosphorus, chlorine, erbium or titanium. Commonly the refractive index of the core glass layer is therefore higher than that of undoped quartz glass. The refractive index of undoped quartz glass is indicated in literature as being between n D =1.4585 and 1.4589 at a measurement wavelength of 589.3 nm (D-line of the sodium vapor lamp). The substrate tube may have one or several core glass layers. In addition to the core glass layer at least one additional layer is provided which in its doping differs from the core glass layer. When viewed across the wall thickness the substrate tube thus has several layers having different doping. These layers are not produced by for example joining together several differently doped tubes or by depositing glass layers on the surface of a quartz glass tube, but directly during manufacture or in subsequent treatment of the porous blank. The substrate tube is obtained by vitrification of the SiO 2 blank.
[0012] The core glass layer comes from a radial portion of the porous blank to which had been added before vitrification a first dopant which increases the refractive index of quartz glass. The SiO 2 blank is commonly produced by flame hydrolysis of a silicon-containing compound and deposition of SiO 2 particles on a substrate according to the so-called ‘soot process.’ The vitrification of the porous SiO 2 blank is accomplished—in contrast to the so-called direct vitrification—in a separate sintering process. Due to its porosity the SiO 2 blank is easily treated before vitrification such as for example for the purpose of cleaning, drying or additional doping. The drying of the porous SiO 2 blank makes it possible to manufacture core glass layers of low OH-content.
[0013] Instead of doping selected portions, the SiO 2 blank can also first have the first dopant distributed homogeneously throughout its entire wall thickness whereby in a later process step the first dopant is at least partially removed from a radial portion, or the refractive index increase caused by the first dopant is entirely or partially compensated or even overcompensated by a second dopant. The distribution of the dopant in the core glass layer can be homogenous, it can also have a gradient, a maximum, or a minimum.
[0014] A chemical or mechanical further treatment of the vitrified blank can take place to set a predetermined surface quality or geometry of the substrate tube, for example by etching or polishing of the surface as well as by elongation to the desired final dimension. In the event that the remaining core glass is made by inner deposition (MCVD or PCVD) in the substrate tube, the substrate tube and core glass combination resulting after inner deposition is collapsed. At the same time additional cladding glass in form of a so called jacket tube can be added and the optical fiber drawn. In the event that the remaining core glass is added to the substrate tube in form of a core glass rod the resulting combination of substrate tube and core glass rod are fused together whereby additional cladding glass can be added in the form of outer tubes (jacket tubes). In case the substrate tube already has appropriate dimensions, an additional jacket might not be necessary.
[0015] From the preform made according to the invention an optical fiber for data transmission can be obtained where the core glass layer contributes to light transmission. The at least one core glass layer is commonly part of a complex refractive index profile. To that extent portions of the preform are provided by the substrate tube which in the known processes is not produced until the core glass itself is produced. The substrate tube itself can be produced by a more economical and more productive OVD process. Insofar the invention replaces expensive and low-effectiveness production processes for the core regions of optical fibers by a more productive manner of manufacture. For example, the core glass layer provided by the substrate tube in the MCVD process would have to be additionally produced by inner coating of the substrate tube. The number and thickness of the inner layers would increase correspondingly while the above-listed disadvantages relating to effectiveness of the deposition would have to be accepted. By contrast, in the process according to the invention, a part of the light transmitting layers is provided by the substrate tube. In this way a productive and effective production of large-volume preforms having complex refractive index profiles is being made possible. The core glass layer provided by the substrate tube contributes to the transmission of light and thus belongs to the core region of the optical fiber. The amount of additional core glass that needs to be added is thus reduced, where “core glass” in the sense of the invention describes that quartz glass material which is needed to complete the core region. The process according to the invention is primarily suitable for the production of single-mode fibers but is also suitable for the production of multi-mode fibers.
[0016] In a preferred practice of the process the porous SiO 2 blank is formed by flame hydrolysis of a silicon compound and deposition of SiO 2 particles on a carrier whereby the first dopant is added during the deposition. In this case the substrate tube—including the core glass layer—is produced according to the OVD process. The adding of the first dopant takes place during the deposition of the SiO 2 particles by adding the dopant as such or in form of a chemical compound to the silicon compound, or by maintaining an atmosphere which contains the first dopant. A non-homogenous distribution of the refractive index across the wall thickness of the SiO 2 blank can be achieved by changing over time the effective concentration of the dopant or the temperature, by subsequent removal of the first dopant from a portion of the SiO 2 blank, or by partial compensating using another dopant.
[0017] The core glass can be introduced into the substrate tube by means of the rod-in-tube method or by inner deposition (MCVD and PCVD), whereby the latter variant is preferred because it simplifies the production of highly pure, especially low-OH, inner layers.
[0018] Especially effective is implementation of the process where at least one second radial portion of the porous SiO 2 blank is doped, after deposition and before vitrification, with a second dopant which alters the refractive index of quartz glass. The second dopant can be distributed homogeneously across the wall thickness of the SiO 2 blank. Such distribution of the second dopant can be realized especially simply and economically by impregnation of the SiO 2 blank with a liquid containing the second dopant or by gas phase diffusion. This facilitates the creation of complex refractive indexes. After vitrification the core glass layer can comprise a mix of a first dopant and a second dopant.
[0019] The doping of the second radial region takes place advantageously by heating of the SiO 2 blank whereby it is exposed to an atmosphere which contains the second dopant. This process (hereinafter called ‘the gas phase doping process’) makes possible a particularly effective and homogenous doping of the SiO 2 blank with a second dopant.
[0020] Fluorine is preferably used as the second dopant. Fluorine reduces the refractive index of quartz glass. The doping of the porous SiO 2 blank or one of its radial regions with fluorine simplifies the manufacture of a substrate tube with a complex refractive index profile. Thus after vitrification the substrate tube can have a cladding layer which has a lower refractive index than quartz glass. Such a substrate tube is particularly suitable for the production of a dispersion-compensating single mode optical fiber (so-called DC fiber). The refractive index profile of this fiber generally comprises a region with a low refractive index and a region with a high refractive index. In comparison with known processes the manufacture of such fibers using the process according to the invention is particularly effective and simple in that both regions can be made available entirely, or at least partially, by way of the substrate tube.
[0021] Advantageously, a chemical compound containing germanium is used as the first dopant. Germanium is present in quartz glass in form of germanium oxide, GeO 2 . Because of its transmission properties germanium oxide is particularly suitable for transmission of light waves in the infrared spectrum.
[0022] It has been shown to be useful to adjust the refractive index of the core glass layer in a range from 1.4593 to 1.490. This permits a particularly economical and effective manufacture of optical fibers having a broad modal field band, especially at a transmission wavelength around 1550 nm. What is meant by the core glass layer is the radial portion of the substrate tube which has a refractive index within the range indicated above. The refractive index may be the same over the entire thickness of the core glass layer, but it may also take any course.
[0023] As far as the substrate tube is concerned, the above-indicated object is achieved on the basis of the substrate tube described initially in that the substrate tube comprises a core glass layer with a refractive index of at least 1.459.
[0024] The substrate tube comprises a core glass layer. By this is meant a radial portion of the entire wall thickness of the substrate tube, which has a refractive index of at least 1.459. The refractive index, measured at a wavelength of 589.3 nm, is thus higher than that of undoped quartz glass which is indicated in the literature at between 1.4585 and 1.4589. The substrate tube may have one or more core glass layers. In addition to the core glass layer at least one additional layer is provided which differs from the core glass layer in its doping. Viewed across its wall thickness the substrate tube thus has several layers of different doping. These layers are not made by for example the joining of several differently doped tubes or by the deposition of glass layers on the surface of quartz glass tube, but instead directly during manufacture or during subsequent treatment of a porous SiO 2 blank. The substrate tube is obtained—as described above—through the vitrification of the SiO 2 blank which is commonly manufactured by flame hydrolysis of a silicon-containing compound and deposition of SiO 2 particles on a substrate according to the so-called “soot process”. The vitrification of the porous SiO 2 blank takes place—in contrast to the so-called “direct vitrification”—in a separate sintering process.
[0025] In an optical fiber which is obtained from a preform made by using a substrate tube, the core glass layer contributes to the transmission of light whereby it is usually part of a complex refraction index profile. Therefore regions of the preform are provided by the substrate tube which otherwise in the known processes is manufactured at great expense during the production of the core glass. This facilitates the effective production of large-volume preforms with complex refractive index profiles. The substrate tube itself can be made by means of a more economical and more productive OVD process. In this case the core glass layer provided by substrate tube contributes to the transmission of light and in this respect belongs to the core region of the optical fiber. The amount of core glass to be additionally added is thus reduced.
[0026] The substrate tube according to the invention may be used for the production of a preform for optical single-mode fibers and also for multi-mode fibers. In any event, a core glass is introduced into the substrate tube. This normally occurs according to the MCVD or the PCVD process by means of deposition of quartz glass layers on the inner wall of the substrate tube and the subsequent collapsing of the substrate tube which is coated on the inside. The substrate tube according to the invention is also suitable for the manufacture of a preform by means of the rod-in-tube technique. A chemical or mechanical treatment may be necessary to adjust the required surface quality or geometry, for example by means of etching and polishing of the surfaces or by elongation of the substrate tube to the desired final dimensions.
[0027] Attention is directed in this regard to the preceding detailed explanation related to the production of a preform according to the invention.
[0028] Advantageously, the core glass layer is provided adjoining to the core glass of the preform. Here, a substantial portion of the light-transmitting region of the preform is provided by the substrate tube whereby the core glass layer may form a part of a homogeneously doped, central core glass region, or a part of a complex refractive index profile. In either case the refractive indexes of the core glass layer and the adjoining core glass may be identical or different.
[0029] It has been shown to be particularly useful if the substrate tube comprises a cladding glass layer made of fluorine-doped quartz glass. Such a substrate tube is particularly suitable for the manufacture of a dispersion-compensating single-mode optical fiber (so-called DC fiber). The refraction index profile of this fiber generally has a region having a low refractive index and a region having a high refractive index. Compared to the known processes the manufacture of such fibers by means of the process according to the invention is particularly effective and simple whereby both regions can be made available completely or at least partially by the substrate tube.
[0030] Advantageously, the core glass layer contains germanium. Germanium increases the refraction index of quartz glass whereby it is present in the core glass in form of GeO 2 . Due to its transmission properties, germanium oxide is particularly suitable for the transmission of light wavelengths in the infrared spectrum.
[0031] A core glass layer with a refractive index in the range from 1.4593 to 1.490 has been shown to be advantageous. A substrate tube of such kind permits a particularly economical and effective production of optical fibers having a broad mode field range at a transmission wave length around 1550 nm. What is meant here by a core glass layer is the radial portion of the substrate tube which has a refractive index falling into the above range, independent of whether the refraction index is the same throughout the entire thickness of the core glass layer or takes a different course.
[0032] It is advantageous, especially in respect to low loss in the infrared wavelength region of fibers manufactured using substrate tubes according to the invention, if the hydroxyl ion content of the core glass layer is max. 1 ppm by weight. Since hydroxyl groups have an absorbing effect in the infrared wavelength region, a low OH content is particularly important in optical fibers in which great value is placed on low loss in this wavelength region. This is true for example for transmission wavelengths around 1310 nm, around 1550 nm, or in a wavelength range inbetween, as are used in optical data transmission technology.
[0033] A particularly well proven embodiment of the substrate tube according to the invention is one where a diffusion-blocking layer is provided adjoining to the core glass layer. The diffusion-blocking layer facilitates the manufacture of step-wise refraction index profiles in that it impedes the undesired diffusion of the dopant into portions beyond the diffusion-blocking layer during later treatment of the porous SiO 2 blank in a dopant-containing atmosphere. Several diffusion-blocking layers may also be present. The diffusion-blocking layer is formed in an easy manner by for example compressing some regions of the SiO 2 blank during the deposition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The invention will be explained in more detail below by exemplary embodiments and a drawing. In particular, the drawing shows schematically in FIG. 1 a , a first refractive index profile of an optical single-mode fiber which was obtained from a preform produced according to the invention; in
[0035] [0035]FIG. 1 b , a substrate tube according to the invention for the production of a fiber having a refractive index profile according to FIG. 1 a ; in
[0036] [0036]FIG. 2 a , a second refractive index profile of an optical single-mode fiber which was obtained from a preform produced according to the invention; in
[0037] [0037]FIG. 2 b , a further embodiment of substrate tube according to the invention for the production of a fiber having a refractive index profile according to FIG. 2 a ; in
[0038] [0038]FIG. 3 a , a third refractive index profile of an optical single-mode fiber which was obtained from a preform produced according to the invention; and in
[0039] [0039]FIG. 3 b , a further embodiment of a substrate tube according to the invention for the production of a fiber having a refractive index profile according to FIG. 3 a.
DETAILED DESCRIPTION
[0040] In the refractive index profiles described below in more detail on the basis of FIGS. 1 a , 2 a and 3 a , the y-axis in each case indicates a relative refractive index differential Δ=(n1−n2)/n2 [in %], where n1 refers to the absolute refraction index in the corresponding light transmitting region of the optical fiber. The reference point n2 corresponds to the refraction index in the outer mantle region of each fiber and is in the subsequent exemplary embodiment always 1.4589 at 589.3 nm. The fiber radius is indicated in μm on the x-axis.
[0041] The refractive index according to FIG. 1 a is typical for a so-called LEAF fiber (large effective area fiber). Such a fiber is described in EP-A2 775 924. The refractive index profile, in comparison to a dispersion-shifted fiber, leads to an enlarged mode field diameter and thus to a lower average energy density in the optical fiber. This is desirable for the reduction of nonlinear effects such as the so-called self-phase modulation (SPM). Furthermore, the profile causes a lower dispersion increase.
[0042] The refractive index profile is distinguished by a total of five core segments. In the inner core segment A with a diameter of about 4.5 μm (radius of 2.25 μm), the relative refractive index differential is Δ=0.6. In the outwardly adjoining core segment B which has a layer thickness of 2.25 μm, the refractive index differential is Δ=0 (there n1−n2). The core segment B is followed by the core segment C which has a thickness of 1.875 μm and a relative refractive index differential of Δ=0. The relative refractive index differential of the core segment D is Δ=0.234 and its thickness is 1.125 μm. The core segment D is in turn enclosed by a core segment E which has a relative refractive index differential of Δ=0 and a thickness of 1.18 μm. The core segment E is followed by the outer optical region of the fiber, made of undoped quartz glass.
[0043] The core segments C, D and E are provided by the substrate tube according to the invention, the core segments A and B are produced in the substrate tube by internal deposition. The boundary surface between the core segments B and C is indicated by a broken line in FIG. 1 a.
[0044] The substrate tube used for the fiber with such a refractive index profile is shown schematically in FIG. 1 b . The substrate tube 1 has an outer diameter of 25 mm and a total wall thickness of 3 mm. The inner layer 2 of the substrate tube 1 is made of undoped quartz glass with a refractive index of about 1.4589 at 589.3 nm. The thickness of the inner layer 2 is 1.21 mm. It is adjoined by an intermediate layer 3 which is doped with about 3% by weight of GeO 2 , which results in the above-mentioned increase of the normal refraction index of Δ=0.234 in the core segment D. The layer thickness of the intermediate layer 3 is 0.84 mm. The outer layer 4 of the substrate tube 1 which has a thickness of 0.95 mm is in turn made of undoped quartz glass. As far as concerns the refractive index profile of the optical fiber obtained by using the substrate tube 1 , the core segment C corresponds to the inner layer 2 , the core segment D to the intermediate layer 3 , and the core segment E to the outer layer 4 .
[0045] The substrate tube 1 is produced according to the OVD process. According to the known process, SiO 2 particles are produced by means of flame hydrolysis of SiCl 4 and are deposited in layers on a rotating mandrel. The Ge-doped intermediate layer 3 is obtained in that during the deposition of the intermediate layer GeCl 4 is added to SiCl 4 . A porous SiO 2 /GeO 2 soot body is obtained. In order to remove hydroxyl groups to a level of under 30 ppb by weight the soot body thus produced is subjected to chlorine treatment at increased temperature. Thereupon the porous SiO 2 soot body is vitrified under formation of a hollow cylinder. The surfaces of the hollow cylinder are mechanically smoothed and then chemically etched. The hollow cylinder pretreated in this way is then elongated to the final dimensions of the substrate tube.
[0046] In order to produce the preform for the optical fiber with the refractive index profile represented in FIG. 1, the inner walls 5 of the substrate tube 1 as shown in FIG. 1 b are first coated by means of the MCVD process with an undoped SiO 2 layer to a thickness of about 1.01 mm and simultaneously directly vitrified. Then a Ge doped layer with a thickness of 0.37 mm is produced in that GeCl 4 is added to the starting material in such a way that a quartz glass is produced with a germanium concentration of about 9% by weight. The resulting refractive index is about 9×10 −3 which corresponds to the core segment A shown on FIG. 1 a.
[0047] Then the internally coated substrate tube is collapsed. The core rod thus produced has an outer diameter of 19 mm. It is then covered by an outer tube (jacket) of undoped quartz glass. The preform thus produced has an outer diameter of about 137 mm. From it are drawn optical fibers having an outer diameter of 125 μm and a refractive index profile of the core region as shown in FIG. 1.
[0048] The refractive index profile according to FIG. 2 a shows a variant of the fiber design shown in FIG. 1 a . This refractive index profile also results in an increased mode field diameter and thus to a lower average light intensity in the optical fiber. Such a fiber is also described in the EP-A2 775,924.
[0049] The refractive index profile according to FIG. 2 a has a total of four core segments. In the core segment A which has a diameter of about 7 μm (radius of 3.5 μm), the relative refractive index differential Δ declines linearly from a maximum of 0.9 (corresponding to about 13×10 −3 over n2, where n2=1.4589) to 0 (zero). In the next core segment B which has a layer thickness of 2.5 μm the relative refractive index differential Δ=0 (the absolute refractive index there=n2). The third core segment C has a layer thickness of 1 μm within which the relative refractive index differential is set at 0.1485. In the next outwardly following fourth core segment D the relative refractive index differential is again n2 and the layer thickness is 4.08 μm.
[0050] The core segments C and D are provided by a substrate tube according to the invention. In this substrate tube the core segments A and B are made by internal deposition. The boundary surface between the outer and inner portion of the core segments is shown by a broken line in FIG. 2 a.
[0051] The substrate tube used to produce the fiber with a refractive index profile according to FIG. 2 a is shown schematically in FIG. 2 b . The substrate tube 21 has an outer diameter of 25 mm and a total wall thickness of 3 mm. The inner layer 22 of the substrate tube 21 is of Ge-doped quartz glass. The thickness of the inner layer 22 is about 0.45 mm, the concentration of the germanium is about 2% by weight, which results in a refractive index increase in the core segment C, shown in FIG. 2 a . The outer layer 23 of the substrate tube 21 has a thickness of 2.55 mm and is in turn again composed of undoped quartz glass. In the case of the refractive index profile of the fiber obtained by using the substrate tube 21 the core segment C is thus formed from the inner layer 22 , and the core segment D from the outer layer 23 .
[0052] The substrate tube 21 is produced according to the OVD process. According to the known process, SiO 2 particles are produced by means of flame hydrolysis of SiCl 4 and are deposited in layers on a rotating mandrel. The germanium-doped inner layer 22 is obtained in that during the deposition of the inner layer 22 GeCl 4 is added to SiCl 4 . After a Ge-doped soot material layer has been deposited which layer in its thickness corresponds to the inner layer 22 , the supply of GeCl 4 is stopped and undoped material continues to be built up. In this way a porous SiO 2 body is obtained. After the removal of the carrier the soot body thus produced is subjected to chlorine treatment at increased temperature in order to remove hydroxyl groups to a level of under 30 ppb by weight. Thereupon the porous SiO 2 dehydrated soot body is vitrified under formation of the substrate tube 21 . The inner and outer surfaces of the substrate tube 21 are then mechanically smoothed and chemically etched.
[0053] In order to produce the preform for the optical fiber with the refractive index profile represented in FIG. 2 a , the inner walls 24 of the substrate tube 21 as shown in FIG. 2 b are first coated by means of the MCVD process with an undoped SiO 2 layer to a thickness of about 0.88 mm and at the same time directly vitrified. Then a Ge-doped layer with a thickness of 0.49 mm is produced in that GeCl 4 is added to the starting material. The refractive index curve in the core segment A (FIG. 2 a ) is produced by a corresponding concentration gradient of GeO 2 within the Ge-doped layer.
[0054] Then the internally coated substrate tube 21 is collapsed. The core rod thus produced has an outer diameter of 19 mm. It is then covered by an outer tube of undoped quartz glass. The preform thus produced has an outer diameter of about 103 mm. From it are drawn optical fibers having an outer diameter of 125 μm and a refractive index profile of the core region as shown in FIG. 2 a.
[0055] The refractive index profile shown in FIG. 3 a is typical of a so-called DC fiber. Such a fiber is described in EP-A2 598,554. The DC fiber is distinguished by a strong negative dispersion at a transmission wavelength of 1550 nm. It is used in order to compensate the positive dispersion at 1550 nm of standard single mode fibers, which is put at about 17 ps/(nm·km) in the literature. In this way high transmission rates can be achieved even with standard single-mode fibers at a transmission wave length of 1550 nm.
[0056] The refractive index profile is distinguished by a total of four core segments. Within the core segment A which has diameter of about 3.8 μm (radius of 1.9 μm), the relative refractive index differential Δ declines parabolically from a maximum of Δ=1.9 to 0. In the core segment B which is disposed next in the outward direction and has a layer thickness of 3.8 μm, the relative refraction index differential is Δ=−0.4. The core segment B is followed by the core segment C which has a layer thickness of 1.9 μm and a relative refractive index differential of Δ=0.4. The relative refractive index differential of the core segment D is again 0 and the segment has a layer thickness of 1.49 μm. The core segment D is followed by the outer optical cladding region of the fiber which is composed of undoped quartz glass.
[0057] The core segments B, C and D are provided by the substrate tube according to the invention. The boundary region between the core segments A and B are indicated in FIG. 3 a by a broken line.
[0058] A first embodiment of the substrate tube used for the production of the fiber with a refractive index profile according to FIG. 3 a , is schematically represented in FIG. 3 b . A more detailed description of the substrate tube and the method of its production follows below.
[0059] The substrate tube 31 has an outer diameter of 25 mm and a total wall thickness of 3 mm. The inner layer 32 of the substrate tube 31 is composed of fluorine-doped quartz glass which has a refractive index lower by 5.8×10 −3 than that of pure quartz glass. The fluorine concentration in the core segment B is approximately 2% by weight and the layer thickness is 1.19 mm. This is followed by an intermediate layer 33 doped with about 10% by weight of GeO 2 and also with 2% by weight of fluorine, which results in the above-mentioned increase of the normal refractive index of 0.4% in the core segment C. The layer thickness of the intermediate layer 33 is 0.95 mm. The outer layer 34 of the substrate tube 31 has a layer thickness of 0.86 mm and is also composed of quartz glass doped with a mixture of fluorine and germanium whereby the fluorine concentration is 2% by weight and the GeO 2 concentration is 5% by weight. The refractive index-raising effect of GeO 2 and the refraction index-lowering effect of fluorine results, at the above-indicated concentrations of these dopants, in a refraction index change of 0 versus undoped quartz glass. In the case of the refractive index profile of the optical fiber obtained by using the substrate tube 31 , the core segment B corresponds to the inner layer 32 , the core segment C to the intermediate layer 33 and the core segment D to the outer layer 34 .
[0060] The substrate tube 21 is produced according to the OVD process. According to the known process, SiO 2 particles are produced by means of flame hydrolysis of SiCl 4 and are deposited in layers on a rotating pin. GeCl 4 is added during the deposition of the intermediate layer 33 and of the outer layer 34 .
[0061] Then the porous SiO 2 soot body is heated to a temperature of about 800° C. in a fluorine-containing atmosphere and homogeneously doped with fluorine across its entire wall thickness. At the same time this lowers the hydroxyl group content.
[0062] The porous SiO 2 soot body is then vitrified under formation of a hollow cylinder. The surfaces of the hollow cylinder are mechanically smoothed and then chemically etched. The hollow cylinder treated in this manner is then elongated to the final dimensions of the substrate tube.
[0063] A second embodiment of a substrate tube for the production of a fiber with a refraction index according to FIG. 3 a and a process for its production will be described below in more detail.
[0064] The substrate tube has an outer diameter of 25 mm and a total wall thickness of 3 mm. The inner layer of the substrate tube is composed of fluorine-doped quartz glass which has a refractive index lower by 5.8×10 −3 than that of pure quartz glass. The fluorine concentration in the core segment B is approximately 1% by weight. The layer thickness is 1.19 mm. This is followed by an intermediate layer doped with about 5.4% by weight of GeO 2 which results in the increase of the normal refractive index of Δ=0.4 in the core segment C shown in FIG. 3 a The layer thickness of the intermediate layer is 0.95 mm. The outer layer of the substrate tube has a layer thickness of 0.86 mm and is composed of undoped quartz glass. In the case of the refractive index profile of the optical fiber obtained by using this substrate tube, the core segment B corresponds to the inner layer, the core segment C to the intermediate layer and the core segment D to the outer layer.
[0065] A process for the production of this embodiment of the substrate tube according to the invention will be described below. The substrate tube is produced according to the OVD process. For this, SiO 2 particles are produced by means of flame hydrolysis of SiCl 4 according to the known process and are deposited in layers on a rotating mandrel, using deposition burners. The surface temperature of the soot body being formed is about 1,400° C. during the deposition. To produce the inner layer, SiCl 4 is used and to it is added GeCl 4 during the deposition of the intermediate layer. The GeCl 4 supply is again stopped during the production of the outer layer. In this way is obtained a porous SiO 2 soot body with a germanium-doped intermediate layer. A distinctive feature of the process is that immediately before the deposition of the intermediate layer a diffusion-blocking layer with a thickness of about 0.5 mm is produced. The SiO 2 soot body has a higher density in the diffusion-blocking layer. This is achieved in that during the deposition of the soot layer which forms the diffusion-blocking layer, a higher surface temperature of the SiO 2 soot body being formed is maintained. For this the supply of fuel gases to the deposition burners is appropriately increased.
[0066] In order to produce the inner fluorine-doped layer the porous SiO 2 soot body is heated and a fluorine-containing gas is fed through the inner opening. The diffusion of the fluorine-containing gas into the germanium-doped intermediate layer is prevented by the diffusion-blocking layer. In this way only the inner layer is doped with fluorine, but not the intermediate layer or the outer layer. The treatment by fluorine-containing gas at the same time lowers the OH-concentration in the inner layer to a level below 50 ppb.
[0067] Then the porous SiO 2 soot body is vitrified under formation of the substrate tube. The surfaces of the substrate tube are mechanically smoothed and then chemically etched.
[0068] In order to produce the preform for the optical fiber with a refractive index profile shown in FIG. 3 a , the core glass which forms the core segment A (FIG. 3 a ) is produced by internal MCVD deposition in the substrate tube. This is described below in more detail by means of FIG. 3 b.
[0069] On the inner surface 35 of the substrate tube 31 according to FIG. 3 b , a SiO 2 layer doped with GeO 2 is deposited by means of the MCVD process and is vitrified directly. During the deposition process the addition of GeCl 4 is continually increased so that a concentration profile of GeO 2 is established which corresponds to the parabolic refractive index profile in the core A shown in FIG. 3 a . The Ge-doped layer thus produced has a thickness of 0.16 mm. The germanium concentration of the layer is maximally about 30% by weight, which leads to a refractive index increase of about 30×10 −3 , as is shown in FIG. 3 a.
[0070] Then the substrate tube produced in this manner is collapsed. The core rod thus produced has an outer diameter of 16.6 mm. It is then enclosed by an outer tube made of undoped quartz glass. The preform thus made has an outer diameter of about 114 mm. From it are drawn optical fibers with an outer diameter of 125 μm and a refractive index profile shown in FIG. 3 a.
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On the basis of a known process for the production of a preform for an optical fiber for optical data transmission technology, the productivity of the process for the production of complex refractive index profiles is to be improved by providing a quartz glass substrate tube which exhibits different doping in radial direction, introducing a core glass made of synthetic quartz glass into the substrate tube and covering the substrate tube with a jacket tube. A substrate tube suitable therefor is also being provided which tube requires less core glass material for the production of the preform, whether during the internal deposition or for the core glass rod in the rod-in-tube technique. Regarding the process it is proposed according to the invention that a substrate tube be used which was obtained by vitrification of a porous tube-shaped SiO 2 blank, the substrate tube being provided with a core glass layer which is produced in that to the first radial portion of the SiO 2 blank there is added before the vitrification a first dopant which increases the refractive index of quartz glass. The substrate tube according to the invention has in the radial direction regions of different doping whereby it incorporates a core glass layer which has a refractive index of at least 1.459.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a battery charging control method, and in particular, to a technique effective for reducing the time necessary for charging a low-temperature battery.
2. Description of the Related Art
Conventionally, hybrid vehicles employing a motor in addition to the engine as a driving source, or electric vehicles employing only a motor as a driving source, are known.
The motors of such vehicles are driven by electric power supplied from a battery; thus, when the remaining charge of the battery decreases, the battery must be charged.
In order to charge a battery which has discharged electricity, it is recommended to charge the battery at one tenth of its rated amount (i.e., 0.1 C.) for approximately 10 hours, and rapid charging of batteries is rarely performed because such rapid charging may cause degradation of the battery and reduction of the battery life.
In particular, the batteries of electric vehicles are generally charged by electric power supplied at night, and the charged power is used in the next day.
However, rapid charging of the battery is still required when a driver has an urgent need to use the vehicle at night, or when a driver wants to extend the driving distance by recharging the battery.
For rapid battery charging, if the battery temperature is below an appropriate range of temperatures for battery charging, that is, lower than Tmin in FIG. 10, the conductivity of the electrolyte decreases and the resistance of the electrolyte rapidly increases, thereby increasing the voltage for charging (see the voltage V in FIG. 10 ).
In particular, the resistance of lithium organic-solvent electrolytes at room temperature is higher than that of aqueous-solution-type electrolytes; thus, the rate of increase of the resistance of lithium organic-solvent electrolytes is very high at low temperatures.
In order to prevent the electrolyte from decomposing due to an increase of the charging voltage (in the case of a lithium battery), or to prevent the generation of gaseous oxygen (in the case of an alkali battery), an upper limit of the charging voltage is determined, and if the charging voltage exceeds the upper limit (see Vmax in FIG. 10 ), the charging current (see current I in FIG. 10) is decreased so as to perform constant-power charging. Accordingly, the charging operation requires a long time, or the amount of charging may not be sufficient.
In order to solve these problems, a charging control method, in which the charging operation is started after the battery is heated using a heater or the like, may be employed. However, in this method, a dedicated heating system is necessary.
Therefore, when a battery is built into a hybrid vehicle or an electric vehicle, a space for providing a heating system must be secured in the layout of the vehicle, and additionally, the weight of the vehicle increases. As a result of these drawbacks, this method is not preferable.
SUMMARY OF THE INVENTION
In consideration of the above circumstances, an object of the present invention is to provide a battery charging control method for reducing the time necessary for charging a battery at a low temperature without providing an additional heating system.
Therefore, the present invention provides a battery charging control method wherein when the temperature of a battery is lower than a predetermined temperature (e.g., 10° C. in the embodiment explained below), the battery is first heated by a pulsed charging and discharging operation comprising alternately executing charging and discharging operations, before the battery is charged.
According to this method, the battery is heated due to a heating effect based on Joule heat (=I 2 ×R, where I denotes the current and R denotes the internal resistance) while the heat related to chemical reactions during charging (i.e., exothermic reaction) and the heat related to chemical reactions during discharging (i.e., endothermic reaction) cancel each other. Therefore, the resistance of the electrolyte is reduced and a rapid increase of the voltage during charging is prevented. Therefore, a battery at a low temperature can be charged in a short time.
The present invention also provides a battery charging control method comprising the steps of:
executing a first pulsed charging and discharging operation when the temperature of a battery is lower than a first predetermined temperature (e.g., 0° C. in the embodiment explained below), wherein in the first pulsed charging and discharging operation, the amount of charging is equal to the amount of discharging; and
switching from the first pulsed charging and discharging operation to a second pulsed charging and discharging operation when the temperature of the battery exceeds the first predetermined temperature, wherein in the second pulsed charging and discharging operation, the amount of discharging is less than the amount of charging.
According to this method, when the temperature of the battery is lower than the first predetermined temperature, the battery is heated due to a heating effect based on Joule heat. Therefore, the resistance of the electrolyte is reduced and a rapid increase of the voltage during charging is prevented. When the temperature of the battery exceeds the first predetermined temperature, the operation is switched from the first pulsed charging and discharging operation under the condition “the amount of charging=the amount of discharging” to the second pulsed charging and discharging operation under the condition “the amount of charging>the amount of discharging”; thus, accomplishing not only heating but also charging. Therefore, a battery at a low temperature can be charged in a shorter time.
Preferably, in the first pulsed charging and discharging operation, for lower temperatures of the battery, a set amount of charging in the charging interval and a set amount of discharging in the discharging interval are chosen to be smaller.
Accordingly, for lower temperatures of the battery (i.e., for larger resistances of the electrolyte), the amount of charging is set smaller, thereby very reliably preventing an increase of the voltage of a low-temperature battery being charged.
Typically, in the second pulsed charging and discharging operation, a set amount of discharging is determined by adjusting at least one of a pulse width and a pulse amplitude. Accordingly, the amount of pulsed discharging can be flexibly determined by suitably restricting the charging time or charging current of each pulse, and various user demands for charging control can be satisfied.
Also typically, the method further comprises the step of switching from the second pulsed charging and discharging operation to a normal charging operation of charging the battery at a continuous current when the temperature of the battery exceeds a second predetermined temperature (e.g., 10° C. in the embodiment explained below).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the structure of a charging control apparatus used for implementing the battery charging control method according to the present invention.
FIG. 2 is a flowchart showing an embodiment of the battery charging control method according to the present invention.
FIG. 3 is a time chart showing a waveform employed in the first pulsed charging and discharging operation.
FIG. 4 is a time chart showing a waveform employed in the second pulsed charging and discharging operation.
FIG. 5 is a time chart showing an example of the normal charging operation.
FIG. 6 is a time chart showing another waveform to be employed in the second pulsed charging and discharging operation.
FIG. 7 is a time chart showing a current pattern used in a pulsed charging and discharging operation, which employs triangular waves.
FIG. 8 is a chart showing the relationship between the battery temperature and the amount of the pulsed charging, which shows the amount of the pulsed charging determined according to the battery temperature.
FIG. 9 is a time chart showing changes of the battery temperature, charged/discharged voltage, charged/discharged current, and remaining charge of the battery when the battery charging control method of the present invention is performed.
FIG. 10 is a time chart showing changes of the battery temperature, battery when a conventional charging control method is performed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an embodiment of the battery charging control method according to the present invention will be explained in detail with reference to the drawings.
A charging control apparatus for implementing the relevant battery charging control method is typically used for charging a battery 1 (see FIG. 1) which supplies electric power to a load such as a motor built into an electric or hybrid vehicle. As shown in FIG. 1, the charging control apparatus comprises a control section 2 , a charger 3 , a current sensor 4 , a voltage sensor 5 , and a temperature sensor 6 .
The current sensor 4 detects the discharge current supplied from the battery 1 to a load such as a motor or generator and also detects the charge current supplied from the load to the battery 1 . The voltage sensor 5 detects the terminal voltage of the battery 1 . The temperature sensor 6 detects the temperature of the battery 1 . A signal corresponding to the current I from the current sensor 4 , a signal corresponding to the voltage V from the voltage sensor 5 , and a signal corresponding to the battery temperature T from the temperature sensor 6 are input into the control section 2 .
Below, the battery charging control method of the present embodiment will be explained with reference to the flowchart in FIG. 2 .
The flowchart of FIG. 2 shows the flow of the charge control operation performed by the control section 2 . In step S 1 of this flow, the temperature range in which the battery temperature (detected by the temperature sensor 6 ) falls is determined.
When the battery temperature T≦0° C. (corresponding to the first predetermined temperature of the present invention), that is, when the battery temperature T falls within a range below the appropriate temperatures for battery charging, if the battery temperature T falls within a lower part of the lower range, then the operation proceeds to step S 2 where a first pulsed charging and discharging operation is executed, while if battery temperature T falls within un upper part of the lower range, then the operation proceeds to step S 11 where a second pulsed charging and discharging operation is executed. When the battery temperature T>10° C., that is, when the battery temperature T falls within a temperature range appropriate for battery charging, the operation proceeds to step S 21 where a normal charging operation is executed.
In step S 2 , a chart (or map) showing the relationship between the battery temperature and the amount of the pulsed charging is referred to, and the amount Ah of the pulsed charging suitable for the battery temperature T is determined. This chart is stored in the control section 2 in advance. FIG. 8 shows an example of this chart, wherein in the range of “battery temperature T≦0° C.”, the lower the battery temperature T, the smaller the amount of charging within the pulsed charging interval and the amount of discharging within the pulsed discharging interval with respect to the pulsed charging and discharging operation.
In steps S 3 to S 5 , the pulsed charging operation at the set amount of charging determined in step S 2 is executed. In this operation, a current I (having a certain pulse amplitude) is determined so as to satisfy the condition that the voltage V detected by the voltage sensor 5 does not exceed the upper limit voltage (Vmax) of the battery 1 .
In lithium batteries, this upper limit voltage indicates a voltage at which the electrolyte may be decomposed, while in alkali batteries, this upper limit voltage indicates a voltage at which gaseous oxygen may be generated. In the present flow, the upper limit voltage is set to be 4.2 V/cell.
At the same time as the start of the pulsed charging in step S 3 , a timer provided in the control section 2 is activated, to start measuring the charging time (corresponding to the pulse width). Here, in step S 3 , the pulsed charging is only used for heating the battery 1 .
In step S 4 , it is determined whether the following condition is satisfied:
0° C.<battery temperature T≦ 10° C.
If the result of the determination is “YES”, that is, when the battery 1 has been heated to a certain temperature and thus a slight amount of charging is possible under the upper limit voltage Vmax, then the operation proceeds to step S 12 . If the result of the determination is “NO”, then the operation proceeds to step S 5 .
In step S 5 , it is determined whether the amount of charging, obtained by multiplying the current I detected by the current sensor 4 by the charging time measured by the above-explained timer, is larger than the set amount of charging which has been determined in step S 2 . If the result of the determination is “YES”, that is, when the present interval of the pulsed charging has been completed, then the operation proceeds to step S 6 where a pulsed discharging operation is started. If the result of the determination is “NO”, that is, when the pulsed charging interval has not yet been completed, the operation returns to step S 3 .
In the following operation from step S 6 to step S 8 , an amount of the pulsed discharging equal to the amount of the pulsed charging (executed in steps S 3 to S 5 ) is discharged. More specifically, in step S 6 , the pulsed discharging is started, in which an amount of current equal to that of the charged current is discharged during a time equal to the charging time (refer to FIG. 3 ). At the same time of the operation start, the timer value indicating the charging time is stored in memory and then the timer value is reset to start measuring the discharging time.
Similar to step S 4 , in step S 7 , it is determined whether the condition “0° C.<battery temperature T≦10° C.” is satisfied.
If the result of the determination is “YES”, the operation proceeds to step S 11 , while if the result of the determination is “NO”, the operation proceeds to step S 8 .
In step S 8 , it is determined whether the amount of discharging, obtained by multiplying the current I (detected by the current sensor 4 ) by the discharging time (measured by the above-explained timer), is equal to the amount of charging by the pulsed charging performed from step S 3 to step S 5 (i.e., current I×timer value stored in memory). If the result of the determination is “YES”, that is, when the present interval of the pulsed discharging has been completed, the operation returns to step S 3 , while if the result of the determination is “NO”, then the operation returns to step S 6 .
In step S 11 , which is executed if the condition “0° C.<battery temperature T≦10° C.” is satisfied in any one of steps S 1 , S 4 , and S 7 , the amount of the pulsed charging is determined by referring to the above-explained chart of the relationship between the battery temperature and the amount of pulsed charging (see FIG. 8 ).
As shown in this chart, in the range of “0° C.<battery temperature T≦0° C.”, a fixed amount of pulsed charging is set regardless of the battery temperature T.
In the above step S 11 , both the amount of pulsed charging and the amount of pulsed discharging are determined. This is because in the range of “0° C.<battery temperature T≦10° C.”, instead of executing the pulsed charging and discharging operation under the conditions that “the amount of charging=the amount of discharging” (which is performed only for heating the battery), a “charge-trend” pulsed charging/discharging operation is performed so as to perform both heating and charging. Therefore, in step S 11 , a smaller amount of pulsed discharging is determined in comparison with the amount of pulsed charging (refer to FIG. 4 ).
In the operation from step S 12 to step S 14 , pulsed charging corresponding to the set amount of charging determined in step S 11 is performed. Similar to the operation from step S 3 to step S 5 , in step S 12 , the current I is determined so as to satisfy the condition that the voltage V detected by the voltage sensor 5 does not exceed the upper limit voltage Vmax of the battery 1 . At the same time of the start of the charging in step S 12 , the timer is activated to start measuring the charging time.
In step S 13 , it is determined whether the condition “10° C.<battery temperature T” is satisfied. If the result of the determination is “YES”, that is, when the battery temperature T has increased to an appropriate temperature range for the charging operation and thus heating using the pulsed charging and discharging operation is unnecessary, then the operation proceeds to step S 14 , while if the result of the determination is “NO”, the operation proceeds to step S 21 .
Similar to step S 5 , in step S 14 , it is determined whether the condition of “the amount of charging>the set amount of charging”. If the result of the determination is “YES”, the operation proceeds to step S 15 to start the pulsed discharging, while if the result of the determination is “NO”, the operation returns to step S 13 .
In the operation from step S 15 to S 17 , a pulsed discharging operation is performed, in which a smaller amount of pulsed discharging is employed in comparison with the amount of pulsed charging performed in steps S 12 to S 14 .
That is, in step S 15 , a pulsed discharging operation is started, in which a current smaller than the charging current is discharged during a time equal to the charging time (refer to FIG. 4 ). At the same time of the start of the discharging, the previous timer value which indicates the charging time is stored in memory and the timer is then reset, so that the measuring of the discharging time is started.
Similar to step S 13 , in step S 16 , it is determined whether the condition “10° C.<battery temperature T” is satisfied. If the result of the determination is “YES”, the operation proceeds to step S 21 , while if the result of the determination is “NO”, then the operation proceeds to step S 17 .
In step S 17 , it is determined whether the amount of discharging, obtained by multiplying the current I detected by the current sensor 4 by the discharging time measured by the timer, is equal to the set amount of discharging determined in step S 11 . If the result of the determination is “YES”, that is, when the present interval of the pulsed discharging has been completed, the operation returns to step S 12 , while if the result of the determination is “NO”, the operation returns to step S 16 .
If the condition “10° C.<battery temperature T” is satisfied in any one of steps S 1 , S 13 , and S 16 , that is, when the battery temperature T is within a temperature range appropriate for the charging operation and thus heating of battery by using the pulsed charging and discharging operation is unnecessary, then step S 21 is executed. In step S 21 , normal charge is started, which employs only a continuous current as shown in FIG. 5 .
In step S 22 , it is determined whether the condition “battery temperature T>50° C.” is satisfied, where the battery temperature T is detected by the temperature sensor 6 . In other words, in this step, it is determined whether the temperature T of the battery being charged is equal to or less than a predetermined temperature, so as to protect the battery and to perform efficient charging. If the result of the determination of step S 22 is “YES”, that is, when the battery temperature T exceeds the upper limit, which is set to 50° C., then the operation from step S 23 to step S 26 is skipped and the charging operation is terminated. If the result of the determination is “NO”, then the operation proceeds to step S 23 .
In step S 23 , it is determined whether the voltage of the battery cell is 4.2 V/cell, by referring to the voltage V detected by the voltage sensor 5 . If the result of the determination is “YES”, that is, when the voltage of the cell has reached the above-explained upper limit voltage Vmax, the operation proceeds to step S 24 . If the result of the determination is “NO”, the operation returns to step S 22 .
In step S 24 , the charge current is decreased so as to perform charging at a constant voltage. Simultaneously, the timer value is reset and the measuring of the charging time at constant voltage is started.
Similar to step S 22 , in step S 25 , it is determined whether the condition “battery temperature T>50° C.” is satisfied. If the result of the determination is “YES”, then step S 26 is skipped and the charge is terminated, while if the result of the determination is “NO”, then the operation proceeds to step S 26 .
In step S 26 , it is determined whether a predetermined time has elapsed from the start of the constant-voltage charge of step S 24 , by referring to the timer value. If the result of the determination is “NO”, the operation returns to step S 25 , while if the result of the determination is “YES”, then the charging operation is completed.
Below, the functions of the battery charging control method of the present embodiment will be explained with reference to FIGS. 3, 4 , and 9 . In FIG. 3, the hatched (or shaded) portions indicated by reference symbol A are converted to Joule heat, the portions indicated by reference symbol B correspond to the actual amount of charging obtained by subtracting the amount converted to Joule heat (see portion A) from the apparent amount of charging, and the portions indicated by reference symbol C correspond to the actual amount of discharging obtained by subtracting the amount converted to Joule heat (see portion A) from the apparent amount of discharging.
If the battery temperature T is lower than the lower-limit temperature appropriate for the charging operation (10° C. in the present embodiment) and is further in a lower range (here, 0° C. or less) below the lower limit, the first pulsed charging and discharging operation is repeated, in which the amount of charging is equal to the amount of discharging (see FIGS. 3 and 9 ). Therefore, the battery 1 is heated by a heating effect due to the Joule heat, thereby preventing a voltage increase during charging.
In particular, the lower the battery temperature T, the smaller the set amount of pulsed charging. This amount of pulsed charging corresponds to the pulse area obtained by multiplying the pulse width (i.e., charging time) by the pulse amplitude (i.e., charging current). Accordingly, a voltage increase during the charging of a low-temperature battery can be reliably prevented.
During the first pulsed charging and discharging operation, the amount of charging is equal to the amount of discharging, as explained above. Therefore, the battery 1 is only heated and the remaining charge of the battery 1 is not increased.
When the first pulsed charging and discharging operation has heated the battery to a temperature exceeding 0° C., the second pulsed charging and discharging operation is repeatedly performed, in which the amount of discharging is smaller than the amount of charging (refer to FIGS. 4 and 9 ). Therefore, charging is performed in addition to heating of battery in the second pulsed charging and discharging operation before the normal charging is performed. Accordingly, even when a battery at a low temperature is charged, the voltage V during the charging does not reach the upper limit voltage Vmax, so that a rapid charging operation can be completed in a short time.
The present invention is not limited to the above-explained embodiments, and the numerical values in the embodiments are merely examples and do not limit the present invention.
For example, in the above embodiments, when the condition “0° C.<battery temperature T≦10° C.” is satisfied, the current (i.e., pulse amplitude) of pulsed discharging is set to be smaller than the current of pulsed charging (see FIG. 4 ). However, as shown in FIG. 6, the discharging time (i.e., pulse width) may be shorter than the charging time.
In addition, the pattern of current of the pulsed charging and discharging operation is not limited to rectangular waves, and triangular waves (see FIG. 7) or other waveforms may be used.
Furthermore, even for a given kind of battery such as lithium batteries or alkali batteries, the first and second predetermined temperatures of the present invention can be flexibly modified according to individual differences.
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A battery charging control method is disclosed, which can reduce the charging time a low-temperature battery without providing an additional heating system. The method includes executing a first pulsed charging and discharging operation when the battery temperature T is lower than a first predetermined temperature (e.g., 0° C.), wherein the amount of charging is equal to the amount of discharging; and switching from the first pulsed charging and discharging operation to a second pulsed charging and discharging operation when the battery temperature exceeds the first predetermined temperature, wherein in the second pulsed charging and discharging operation, the amount of discharging is less than the amount of charging. Therefore, it is possible to accomplish not only heating but also charging. When the battery temperature T exceeds a second predetermined temperature (e.g., 10° C.), a normal charging operation is performed.
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BACKGROUND OF THE INVENTION
Amino acids are important food additives in both human and animal diets and their production and purification have become vital to numerous food industries. Many amino acids are made either chemically or through fermentation processes which require the separation and isolation of the desired amino acids from the broth.
Many amino acids exist as two optically active enantiomers, the L and D-isomers. It is often preferred in many applications to separate the two from their racemic mixture that is produced during chemical processing. L-phenylalanine for example, is a component of the popular dipeptide sweetener aspartame, technically known a alpha-L-aspartyl-L-phenylalanine methyl ester (APM). It is also known that when the dipeptide is comprised of the two L-isomers of aspartic acid and phenylalanine, it is sweet, whereas their D-L, L-D, D-D etc. enantiomers are not. Moreover, any of the enantiomers which contain D-phenylalanine are worthless as sweeteners.
Aspartame can by synthesized by any one of several biochemical processes but these generally involve a coupling reaction whereby aspartic acid is joined with either phenylalanine or its methyl ester. Hence, the finished product must be separated from its enantiomers and any unreacted phenylalanine and aspartic acid. It is economically advantageous to conserve L-phenylalanine by hydrolysing the non-sweet esters and recovering the phenylalanine. However, during the various chemical process steps used to make APM and recover the leftover phenylalanine, some of the L-phenylalanine is racemized. Therefore, when this phenylalanine is recovered, it contains some of the D-isomer. Since the D-isomer cannot be utilized in the manufacture of the dipeptide sweetener, it would be useful to be able to separate the L-phenylalanine isomer as economically as possible from the racemic mixture.
It is an object of the present invention to crystallize and isolate pure L-isomers of an amino acid from a racemic mixture when the racemate has more of the L-isomer than the D-form. More specifically, it is an object of the present invention to obtain pure L-phenylalanine from a racemic mixture comprised of both the L- and D-forms.
Various methods for separating the L and D isomers, are known and generically are referred to as resolution. The most common method of resolving D,L-mixtures involves combining them with an optically active compound known as a resolving agent, followed by fractional crystallization of the resulting mixture of compounds (diastereroisomers) in solution. For practical resolution, it is necessary to find a combination of resolving agent and solvent which will give good crystallization behavior together with a pronounced difference in solubility between the diastereoismers. Examples of this technique as applied to the resolution of an amino acid are in U.S. Pat. Nos. 2,556,907, Emmick, R., and 2,657,230, Rogers, A. These patents discuss methods to resolve D, L-lysine in which optically active glutamic acid is employed as the resolving agent.
More recently, phenylalanine has been resolved by enzymatic hydrolysis of its diastereroisomers. The enzyme, chymotrypsin, selectively hydrolyzes L-phenylalanine esters. Hence L-phenylalanine is recovered from a mixture of the D,L-phenylalanine ester. An example of this process is Eur. Pat. Appl. No. EP 174,862, Empie, M., (8/17/84).
However, the aforementioned methods of the prior art require an additional step beyond that of the fermentation involving the use of a resolving agent in a chemical or enzymatic reaction or some combination of these to form a derivative of phenylalanine in order to isolate the desired isomer. The present invention permits the separation of the L-isomer from the racemic mixture and in the same step, its purification from other amino acids, salts, etc., without the requirement of a resolving agent, the subsequent formation of a derivative of the amino acid in question and without enzymatic reaction.
SUMMARY OF THE INVENTION
A method for the selective crystallization of the L-isomer from a D, L mixture of amino acid isomers is described. More specifically, a method is set forth for the selective crystallization of L-phenylalanine. Further, a method is described to prepare a mother liquor rich in L-phenylalanine by crystallizing and separating the isomers of the racemate, then selectively crystallizing L-phenylalanine from this liquor. Pure L-phenylalanine cay be crystallized from racemate under a vacuum at temperatures between approximately 5.0° C. and 65.0° C. if after crystallization the D-phenylalanine is about 7.0% or less of the total phenylalanine left in solution. A racemate crystal comprised of approximately 50% D- and 50% L-phenylalanine can be crystallized from racemate at the above temperatures if after crystallization the D-phenylalanine is about 7.0% or more of the total phenylalanine left in solution. Crystallization conditions must include slow crystal growth and crystal digestion to assure the desired composition of crystals of pure L-phenylalanine or of 50% racemate. When the ratio of the D-isomer to total phenylalanine is about 7.0% or greater, further precipitation of L-phenylalanine which is contaminated with less than 7.0% D-phenylalanine is possible between approximately 5.0° C. and 55.0° C., if the solution is seeded with pure L-phenylalanine, followed by a digestion time, and then slow crystallization.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 relates to the enrichment of L-phenylalanine in solution phase.
FIG. 2 relates to evaporative crystallization of solutions of D-phenylalanine.
FIG. 3 relates to a schematic representation of the recovery of L-phenylalanine from the racemate.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is based on the fact that the D- and L-isomers of phenylalanine combine to form racemic crystals of phenylalanine that are only half as soluble as either of the two isomers alone. The presence of excess L-phenylalanine reduces the solubility of the D,L phenylalanine complex. Surprisingly, there is a limit to this effect and the limit occurs at approximately the same relative ratio of D-phenylalanine to total phenylalanine (D/T) under a range of temperature of solution or solution concentrations of total phenylalanine. This phenomena will be referred to as "the limit ratio" or the "equal saturation point." At this limit, the physical state of the solution may be described as being saturated with L-phenylalanine and the D,L-phenylalanine complex.
Surprisingly, at relatively low levels of D-phenylalanine, below the limit ratio, pure L-phenylalanine crystals will precipitate upon evaporative crystallization. This will continue until the relative solution concentration of D-phenylalanine rises to become approximately 7.0% of the total phenylalanine in solution (D/T≅7.0%). Pure L-phenylalanine can be crystallized from racemate under a vacuum at temperatures between approximately 5.0° C. and 65.0° C. if before crystallization the D/T is less than 7.0% and after crystallization the D/T is about 7.0% in solution.
At higher relative concentrations of D-phenylalanine in the racemic mixture, i. e. where the D/T >7.0%, a racemic D,L crystal precipitates upon evaporative crystallization until the relative concentration of D-phenylalanine is reduced to about 7.0% A racemate crystal comprised of approximately 50% D- and 50% L-phenylalanine can be crystallized from the racemate mixture between approximately 5.0° C. and 100° C. if, before crystallization, the D/T is above 7.0% and after crystallization the D/T is greater than or equal to about 7.0% in solution. To assure the desired composition of crystals of pure L-phenylalanine or of the 50% racemate, crystallization and crystal digestion should be conducted at a slow rate.
FIG. 1 illustrates the enrichment of L-phenylalanine in the solution phase by precipitation of the racemate. Various weights of phenylalanine were added to water and the volume of water was brought to 1 liter after dissolution of the sample. The solutions were cooled to approximately 50° C. and then filtered. The phenylalanine batched into the experiment was 17.35% D-phenylalanine (i.e., high D-isomer concentration). The x-axis is the percent of the phenylalanine which was precipitated out of solution. The y-axis is the specific rotation of the phenylalanine in the resultant solution phase. The resultant solution concentration of phenylalanine was approximately equal in all cases and was approximately 45 gm/l. This supports the existence of the equal saturation point or limit ratio of D/T in solution, since the specific rotation of the phenylalanine in solution rises as more phenylalanine precipitates, but only to a certain point.
In FIG. 2, the starting solution was at the equal saturation point. The specific rotation (S.R.) of the phenylalanine in the solid phase can be compared to that in the solution phase. At low evaporation ratios, the specific rotation of phenylalanine in either phase is the same. The composition of the liquid and solid phases should therefore remain equal as a solution at the equal saturation point is concentrated. An unexpected observation is that racemization occurs with further concentration. Moreover, the extent of racemization is proportional to the extent of evaporation. The S.R. of the solution phase doesn't change with the extent of evaporation which facts supports the existence of an equal saturation point or limit ratio of D/T.
When the D/T is about 7.0%, further precipitation of phenylalanine from solution maintains the relative solution concentration of the isomers. Hence, a racemic solution with an enantiomeric excess of L-phenylalanine will produce either pure L-phenylalanine, a racemate composed of 50% D- and 50% L-phenylalanine or a mixture of the two crystal compositions.
However, the composition of the crystal phase might be effected by kinetic factors. If there are little or no racemate crystals upon which the crystallization process can build, but there is an excess of L-phenylalanine crystals, then L-phenylalanine crystallization is carried out and the relative concentration of D-phenylalanine in solution would increase. Digestion in the presence of pure L-phenylalanine seed favors crystallization of L-phenylalanine and a rise in the relative concentration of D-phenylalanine in solution. When the ratio of D- to total phenylalanine is about 7.0%, further precipitation of L-phenylalanine with less than 7.0% D-phenylalanine is possible between approximately 5.0° C. and 55.0° C. if the solution is seeded with pure L-phenylalanine, followed by digestion and then slow crystallization.
By combining processes of (1) precipitation of pure L-phenylalanine, (2) precipitation of a racemate composed of 50% D- and 50% L-phenylalanine and (3) selective crystallization, it is possible to separate excess L-phenylalanine from a less than 50% racemate, so that the result of the separation is a nearly 50% racemate on the one hand and nearly pure L-phenylalanine on the other. It is therefore possible to make racemate at any lesser level of D-phenylalanine.
A model of the relationship of the D-phenylalanine in starting material to D-phenylalanine in the crystal product, and to D-phenylalanine in the mother liquor exists in the following equation. If the starting material has a very low D/T, this equation can be used to predict how much L-phenylalanine can be precipitated before it would likely become unacceptably contaminated by D-phenylalanine due to further precipitation. At very high D/T, it can predict how much racemate can be precipitated to maximize the L-phenylalanine enrichment of the mother liquor.
%Dt=% Dp(%P)+0.07(% S)
Where:
%Dt=relative percent D-phenylalanine in starting material,
%Dp=relative percent D-phenylalanine in product,
%P=percent of starting material in product,
%S=percent of starting material left in solution, and
0.07=the estimate of the relative percent D-phenylalanine at the equal saturation point.
For example, if the starting material contains 3.0% D-phenylalanine and as much as 1.5% D-phenylalanine would be acceptable in the product, it would be possible to dissolve and reprecipitate approximately 73% of the starting material as product. In another embodiment, if the starting material had 30% D-phenylalanine and the racemate would be expected to contain 47% D-phenylalanine, then the recovery of L-phenylalanine enriched solution can be maximized at 7.0% by dissolving and precipitating approximately 57.5% of the starting material as racemate product.
Another embodiment of the invention is the recovery of an L-phenylalanine enriched fraction from a racemic mixture by selective crystallization. The racemic mixture could be an L-phenylalanine enriched mother liquor which could be created as in the second example in the previous paragraph. This method involves the addition of an L-phenylalanine seed and a period of time for digestion of the seed crystals. This method favors enrichment of L-phenylalanine in the precipitate and affects the relative rate of growth of the two crystals.
FIG. 3 represents a general schematic representation of how the above methodologies may be combined in a commercial process. The starting material is D,L-phenylalanine recovered from an aspartame (APM) mother liquor. The D,L-phenylalanine is batched into the dissolution tank and combined with any recycled mother liquor. The solution is heated to a temperature range of approximately 60°-100° C., preferably the upper limit of 95°-100° C. in order to insure that most of the L-phenylalanine is dissolved into solution. It is then possible to dissolve L-phenylalanine out of an otherwise approximately 50% D-phenylalanine racemate without totally dissolving the racemate. When the solution is cooled, the racemate is removed, leaving an L-phenylalanine enriched mother liquor. The temperature at which the racemate is removed should be approximately the same as that of the crystallizer during the digestion period. Darco carbon may optionally be added and mixed with the solution in the dissolution tank. The carbon can be removed with the racemate and the two may be removed by any standard filtration device such as the darco press known in the art. Carbon treatment of the mother liquor removes impurities which may interfere with crystallization or diminish the quality of the L-phenylalanine product.
The amount of phenylalanine to be batched into the dissolution tank must be calculated by taking into account the D-phenylalanine concentration of both the starting material and of the recycled mother liquor. The D/T of these combined sources is %D in the following equation. The racemate which is removed to produce the L-phenylalanine enriched mother liquor is the DL-loss in the equation. This percentage is also the amount of phenylalanine above that required to obtain the solution concentration desired in the crystallizer which must be batched into the dissolution tank. This equation is derived from the previous equation where the mother liquor is estimated to contain 7.0% D-phenylalanine and the racemate is estimated to contain 47% D-phenylalanine.
DL-loss %=((%D×100)-700)/40
For example, if the starting material had 30% D-phenylalanine and racemate, 57.5% of the material is precipitated as racemate. This is as in the previous example. If the digestion temperature is 50.0° C., then the solution concentration desired is about 45 gm/l. Therefore, the concentration to be batched in the dissolution tank is 106 gm/l.
Before transferring the L-phenylalanine enriched mother liquor to the crystallizer, the crystallizer and transfer lines should be heated slightly above the digestion temperature, since any sudden cooling of any part or portion of the racemate solution may result in the formation of the wrong crystal type.
The mother liquor, once transferred to the crystallizer is then seeded with a generous dose of pure L-phenylalanine crystals in order to initiate precipitation of pure L-phenylalanine from solution. This is followed by the addition of a Tween surfactant and a digestion period. The digestion temperature is preferably approximately 45.0° to 65.0° C. but may range from approximately 20.0° C. to 65.0° C. Digestion improves the purity of L-phenylalanine which is subsequently crystallized out of solution. The Tween removes some of the interstitial water. The crystals are formed by slowly cooling the solution.
The L-phenylalanine crystals thus formed are centrifuged and removed from the mother liquor as it is cooled to approximately 15.0°-25.0° C., preferably 20.0° C., and the crystals are removed as they precipitate. Failure to remove the crystals in this manner may result in an unmanageably thick slurry. During crystallization, the mother liquor is recycled back into the crystallizer from the centrifuge to maximize crystal recovery. When crystallization is complete, and no more crystals can be recovered, the mother liquor is recycled to the dissolution tank for the next batch. Before repeating the process, it is important to wash the crystallizer, centrifuge and process lines to remove any remaining crystal. The wash may be discarded. The presence of any remaining crystal may subsequently interfere with selective crystallization.
Other embodiments of the present invention is a process for the co-recovery of L-phenylalanine from racemate and of L-phenylalanine from fermentation broth. The L-phenylalanine is recovered by evaporative crystallization, followed by re-dissolution, treatment of the dissolved phenylalanine with carbon to remove any impurities and recrystallization. Each crystallization leaves a mother liquor, all or part of which is discarded. The discarded liquor can be used as a bleed stream for D-phenylalanine. The maximum bleed required is such that all of the D-phenylalanine which is produced during the recovery and added to the recovery stream leaves with the discarded liquor. This can be accomplished if the D-phenylalanine in the discarded liquor is no more than 7.0% of the total phenylalanine in this stream (i.e. D/T≦7.0%). Under some conditions, the D/T of the mother liquor can be higher.
Pure L-phenylalanine can also be recovered from the mother liquor by converting the phenylalanine present as a racemate to its salt. By doing this, the solubility of the 50% D-phenylalanine racemate will increase. For example, the solubility of the racemate increases under each of the following conditions:
(1) when NaOH is used to give a solution of 50% racemate a high pH,
(2) NaHCO 2 is added and heated to produce a sodium salt of the 50% racemate, or
(3) acetic acid is used to give a solution of 50% racemate a low pH.
As a sodium salt, the racemate is twice as soluble as pure L-phenylalanine under the same conditions. A high concentration of salt may also cause this apparent increase in racemate solubility.
However, without selective crystallization, excess L-phenylalanine, precipitated under conditions described in the above paragraph, is not pure and usually has only a slightly reduced D/T as compared to the solution's D/T before crystallization.
By using the principles of selective crystallization, excess L-phenylalanine can be precipitated as pure L-phenylalanine and the D/T of the waste stream can exceed 7.0%. Hence, during evaporative crystallization of a low D/T racemate, in the presence of a high concentration of ammonium sulfate, the average D/T of the mother liquor may increase as the salt concentration increases and a pure L-phenylalanine can be recovered. However, the total solubility of phenylalanine in the mother liquor will also decrease. The disadvantage of this higher D/T in the mother liquor is that these solutions become less stable as the D/T increases, and therefore can suddenly precipitate out 50% racemate to contaminate otherwise pure L-phenylalanine. Therefore, even with selective crystallization it is best if the mother liquor D/T is not in excess of much more than 7.0% (i.e. D/T≦15.0%)
The following examples are set forth in order to better demonstrate the preferred embodiments of the present invention. They are for illustrative purposes only and are not intended to limit the spirit and scope of the invention as recited in the claims that follow.
EXAMPLE 1
A racemic mixture containing 30% of the D-isomer was dissolved in fifteen (15) liters of water to a concentration of 30 gm/l at a temperature of 80° C. and a pH of approximately 4.5. At this pH, the non-hydrated form of the L-phenylalanine isomer dominates. The solution was fed into the crystallizer and for every five liters of solution, 3.750 liters of water was removed by evaporation at 55° C. under vacuum. The concentrate was then cooled to 50° C. and filtered producing an L-phenylalanine rich mother liquor. The mother liquor from three batches prepared in this manner were combined and one liter of water was added to this. A second evaporative crystallization was then carried out at 80° C. under vacuum until 2.75 liters of water were removed. One gram of L-phenylalanine was added as a seed for crystallization when an additional 2.4 liters of water had been removed by evaporation. This final concentrate was filtered and the crystals that had precipitated out of solution were removed.
The first batch of crystals filtered out of solution weighed 273.85 gm and had a specific rotation of -13.5. These were found to be comprised of the D,L isomer as expected. The second batch of crystals precipitated out of solution weighed 46.17 gm and was found to have a specific rotation of -32.3. This was found to be comprised 99.7% pure L-phenylalanine.
EXAMPLE 2
Several L-phenylalanine purification runs were conducted according to the recovery procedure outlined as FIG. 3. The D,L racemate was batched into the dissolution tank at the relative concentrations of D-phenylalanine as set forth below for three separate lot runs. Each lot was then processed according to the present invention through four cycles. The numbers listed are in grams. The relative concentration of D-phenylalanine in the starting material is shown in parenthesis.
__________________________________________________________________________ CYCLE I CYCLE II CYCLE III CYCLE IV__________________________________________________________________________INPUTLot A 8871.01 3617.22 3617.22 3617.22 (16.8%) (20.1%) (20.1%) (20.1%)Lot B 2565.90 3614.91 3614.91 3614.91Lot C 4489.74 3614.80 3614.80 3614.80Recycle -- 6540.88(a) 6645.45(b) 6297.45(c)Darco Press Blow -- 1169.66 944.17 1552.32OutSeed (L-phe) 23.00 23.00 23.00 23.00Total 15949.65 18580.47 18459.55 18719.70Output 105 -DL-Phe 3245.20 7586.44 6717.85 7986.72Darco Press Blow 1169.66 944.17 1552.32 1547.26OutRecycle 6540.88 6645.45 6297.45 6592.49 (a) (b) (c)L-Phe Pure 419.62 3692.65 3409.08 2940.99Total 15146.36 18868.71 17976.70 19067.46% D-Phe in Pure 1.08 1.21 1.10 1.91*L-Phe RecoveryFraction__________________________________________________________________________ a, b, and c represents grams of phenylalanine that was recycled. Cycle I had no recycled phenylalanine in the initial batch.
It is clear from the above data that a recovery of substantially pure L-phenylalanine can be expected by the methods of the present invention. With starting material containing an extreme excess of enantiomeric L-phenylalanine it is possible to apply the principle of equal saturation point that leaves the D-phenylalanine in solution while precipitating substantially pure L-phenylalanine. When the starting material contains lesser relative concentrations of L-phenylalanine it is possible to use the equal saturation point to precipitate the D,L racemic crystal from solution leaving the motor liquor enriched with L-phenylalanine. The desired L-isomer can then be purified and isolated from the mother liquor by selective crystallization. The method may also be practiced in the crystallization and purification of other amino acids with slight variations in the procedure.
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A method for the isolation of a substantially pure L-isomer of an amino acid from its D,L racemic mixture does not require the use of a resolving agent, the formation of a derivative of the amino acid or additional enzymic reactions.The method is based upon the concept of the equal saturation point wherein the L-isomer can be separated from the D-isomer by precipitation of the L-isomer when the relative concentration of the D-isomer is less than 7.0% or by precipitation of the D,L racemate when the relative concentration is greater than 7.0%. Selective crystallization through seeding allows for further isolation of pure L-isomer when its relative concentration in solution is very low.
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BACKGROUND OF THE INVENTION
1a.
This invention relates to a so-called frame-thinning type half-tone representation system, and more particularly to a half-tone representation system which is suitable for use with a multi-color liquid crystal display apparatus.
2b.
Japanese Laid-open Patent Application No. 58-57192 shows a half-tone representation system for a monochrone liquid crystal display apparatus with high-speed blinking of picture elements or pixels.
This prior art half-tone representation system is described below with reference to FIGS. 2, 3, 4 and 5.
FIG. 2 shows a block diagram of such a prior art half-tone representation system. In the drawing, an oscillator for generating a 8-dot reference clock or character clock signal 2 is indicated at 1; display address signal generator responsive to reference clock signal 2 for cyclically generating display addresses 4 for a single frame is indicated at 3; and display memories for storing 8-bit display data 61-64 are indicated at 51-54. Pieces of display information are stored in each of the memories 51-54 in one-to-one correspondence relation, and 8-bit display data 61-64 retrieved from each of memories 51-54 are in one-to-one correspondence relation in terms of bit unit. When all display data 61-64 are "LOW", "display OFF" is indicated; when all display data 61-64 are "HIGH", "display ON" is indicated; and otherwise, half-tone representation is indicated. A timing signal generator is indicated at 9; a frame signal is indicated at 10; a line signal is indicated at 11; a data shift signal is indicated at 12; and an AC drive signal is indicated at 13. The timing signal generator 9 generates the frame signal 10, the line signal 11, the data shift signal 12 and the AC drive signal 13 in response to the character clock signal 2. A half-tone controlling circuit is indicated at 14; a divide-by-three frame counter which uses the frame signal 10 as a clock signal for cyclically generating "0", "1" and "2", is indicated at 15; a frame count outputted by frame counter 15 is indicated at 16; a half-tone signal generator is indicated at 24; and a half-tone signal is indicated at 25. The half-tone signal generator 24 outputs a half-tone signal of "HIGH" when frame count 16 is, " 0", and a half-tone signal of "LOW" when frame count 16 is "1" or "2". A display controlling circuit is indicated at 21 and 8-bit liquid crystal display data is indicated at 22. The display controlling circuit 21 functions to output as liquid crystal display data, a binary signal "HIGH" for normal representation or "display ON"; a binary signal "LOW" for "display OFF"; and is also controlled by half-tone signal 25 for half-tone representation. Liquid crystal display panel 231 composed of "m" dots x "n" lines is responsive to the liquid crystal display data 22 for providing visual representation of the data.
In FIG. 2, the display address generator circuit 3 functions to output addresses 4 to the display memories 51-54, thereby retrieving display information from memories 51-54. Each of the retrieved display information is of 8 bits, and is directed as display data to the display controlling circuit 21. The display controlling circuit 21 is responsive to the binary condition of each bit of display data 61-64 for outputting 8-bit liquid crystal display signal 22 to the liquid crystal display panel 231, specifically outputting display data signal of "HIGH" for normal display or "display ON"; display data signal of "LOW" for "display OFF"; of half-tone data which is "HIGH" in each one out of three frames in response to signal 25. The display address generator circuit 3 sequentially supplies display data 8 bits at a time to the liquid crystal panel 231 so as to sequentially provide display data of a frame. The liquid crystal display panel 231 functions to sequentially latch the liquid crystal display data 22 with data shift clock 12. After latching sufficient liquid crystal display data 22 to fill a full line of "m" dots, visual representation may be provided by means of line clock pulse 11, which pulse appears once for each line. This will be repeated "n" times to provide visual representation in a single frame. The beginning of each frame is indicated by the frame signal 10, and the liquid crystal display panel 231 is responsive to each appearance of "HIGH" frame signal 10 for beginning visual representation with the top line.
The above procedure is repeated to provide visual representation of all information stored in the memories 51-54.
FIG. 3 shows how liquid crystal panel 231 provides normal and half-tone representation of the liquid crystal display data 22 in the "0"th, 1st and 2nd frames.
Now, assume that information representing the letter "A" is stored in each of the display memories 51-54, and that information representing the letter "B" is stored only in the display memory 51. Then, the display controlling circuit 21 functions to output a binary signal of "HIGH" in each frame for the letter "A" and a half-tone signal 25 for the letter "B". Specifically, since frame counter 15 provides "0" in the "0"th frame, the half-tone signal 25 is "HIGH", allowing liquid crystal display panel 231 to provide visual representation of both letters "A" and "B" in the "0"th frame. The half-tone signal 25 is "LOW" in the 1st and 2nd frames, and then no visual representation of the letter "B" is caused in liquid crystal display panel 231 in these frames. Thus, the letter "B" will appear in only one frame out of three frames, and as a result the effective voltage applied to the liquid crystal panel 231 lowers compared with that for the letter "A". Thus, half-tone representation of the letter "B" is realized.
FIG. 4 shows a block diagram of a conventional liquid crystal display apparatus employing a multi-color liquid crystal display panel. Color liquid crystal display panel is indicated at 23; and red (R), green (G) and blue (B) liquid crystal display data are indicated at 221, 222 and 223. Same components as appear in FIG. 2 are indicated at same reference numerals in FIG. 4.
Display controlling circuit 21 is responsive to display data 61-64 for providing R-liquid crystal display data 221, G-liquid crystal display data 222 and B-liquid crystal display data 223, each of which will be "HIGH" for normal display or "display ON", "LOW" for "display OFF", and will be controlled by the half-tone signal 25 for half-tone representation. Color liquid crystal display panel 23 includes dots each made up by a R-pixel, G-pixel and B-pixel. The R-pixel provides a visual representation of R-liquid crystal display data 221; the G-pixel provides visual representation of G-liquid crystal display data 222; and the B-pixel provides a visual representation of B-liquid crystal display data 223. The operation of the system of FIG. 4 is essentially the same as that of FIG. 2, except for the following:
FIG. 5 show how color liquid crystal panel 23 provides half-tone representation of R-, G- and B-liquid crystal display data 221-223 in the "0"th frame, the 1st frame and the 2nd frame. In the drawing, visual half-tone representation of the letter "A" is provided for every R-, G- and B-pixel.
The above described prior art permits half-tone representation, but disadvantageously flickers are caused by ON-OFF control of every pixel in a selected frame or frames. The lightness characteristics of the filters used in a color display panel are not taken into consideration, and therefore it is difficult to provide desired half-tone representation.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a half-tone representation system and half-tone representation controlling apparatus without causing flickering in the half-tone representation.
Another object of the present invention is to provide a half-tone representation system and half-tone representation controlling apparatus which are capable of providing half-tone representation in conformity with the lightness characteristics of the color filters used in a liquid crystal display panel.
According to one aspect of the present invention, there is provided a half-tone representation system in which each display dot is constituted by a set of N color pixels (N: an integer of two or more), each pixel being capable of being ON-OFF controlled to provide N different colors represented by a combination of ON and OFF states of the N color pixels, the half-tone representation system characterized in that colors other than said 2 N different colors are provided by successively ON-OFF controlling any one or more of said N color pixels, and that the patterns of successively ON-OFF controlling of the N color pixels are different in phase from one another.
In this system, the patterns themselves may be caused to be different instead of the phases of the patterns.
According to another aspect of the present invention, there is provided a half-tone representation system in which each display dot is constituted by a set of three primary color pixels, each pixel being capable of being ON-OFF controlled to provide eight different colors, the half-tone representation system being characterized in that colors other than said eight different colors are provided by a frame thinning operation of any one or more of said three primary color pixels, and that timings of the frame thinning of said three primary color pixels are different from one another.
In still another aspect of the present invention, there is provided a half-tone representation system in which each display dot is constituted by a set of three primary color pixels, each pixel being capable of being ON-OFF controlled to provide eight different colors, the half-tone representation system being characterized in that colors other than said eight different colors are provided by a frame thinning operation of any one or more of said three primary color pixels, and that the frame thinning operation is performed such that the frame thinnings of said three primary color pixels never occur at time.
In still further aspect of the present invention, there is provided a half-tone representation system in which each display dot is constituted by a set of three liquid crystal pixels with three primary color filters attached thereon, each pixel being capable of being ON-OFF controlled to provide eight different colors, the half-tone representation system being characterized in that colors other than said eight different colors are provided by a frame thinning operation of any one or more of said three primary color pixels, and that rates of the frame thinning of said three primary color pixels are different from one another.
The present invention also provides a half-tone representation controlling apparatus adapted to effect a control based on display data of a color display panel which has display dots each being constituted by a set of N color pixels, each of the pixels being capable of being ON-OFF controlled, the half-tone representation controlling apparatus comprising: a frame counter for counting the number of display frames of the color display panel; N half-tone signal generators each for producing an "ON" signal during a time when the count of said frame counter is a predetermined value or values which are different for each of the N half-tone signal generators; and a control circuit responsive to the display data which represents a half-tone color for outputting selected or all of the half-tone signals to said color display panel in place of a part or all of said display data.
In this half-tone representation controlling apparatus, each of said N half-tone signal generators may have a separate frame counter assigned thereto. In this case, maximum counts and said predetermined values of the separate frame counters are preferably set such that the proportion of lightnesses of said N color pixels all in "ON" states are equal to that of the lightness of said N color pixels all in "half-tone" states.
The present invention further provides a color display panel, comprising: a multitude of display dots disposed on the color display panel, each of the display dots being constituted by a set of N color pixels each capable of being ON-OFF controlled; and one of the half-tone representation controlling apparatuses, the apparatus being built in the color display panel.
A half-tone display system according to the present invention employs the intermittent ON-OFF controlling of a selected one or ones or all of the pixels which make up each display dot. The minimum time unit in which the intermittent ON-OFF controlling of pixels can be performed, may be practically a "frame period", that is, a length of time for which a single frame is provided, and OFF-controlling on the basis of a frame period is referred to as "frame-thinning". However, the time unit on the basis of which the intermittent ON-OFF controlling is performed on pixels may be other than the frame period.
The inventors found that the cause for flickering is present in the coincidence between the ON-OFF patterns and the timings for pixels. In an attempt to reduce the flickering in half-tone representation, the ON-OFF pattern for performing the ON-OFF control on each color pixel is changed in phase, or the ON-OFF pattern itself is changed so that the ON-OFF timing on each of the color pixels together constituting each dot is different from the ON-OFF timing on other pixels. This avoids coincidences of the ON-OFF timings on the pixels which make up a dot, thus reducing the flickering.
In a case using a multi-color display panel whose pixels have different color filters associated therewith, the frame thinning rate is changed with each different color, thereby compensating for the difference between the lightness characteristics of different color filters.
Other objects and advantages of the present invention will be understood from the following description of half-tone representation system and half-tone representation controlling apparatus according to preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a display apparatus using a liquid crystal display controlling circuit according to one embodiment of the present invention;
FIGS. 2 and 4 are block diagrams of conventional liquid crystal display controlling circuits;
FIGS. 3 and 5 show how liquid crystal display data are related with subsequent frames to provide normal and half-tone representation in a liquid crystal display panel;
FIG. 6 shows how liquid crystal display data are related with subsequent frames to provide half-tone representation in a liquid crystal display panel according to the present invention;
FIG. 7 is a wiring diagram of half-tone controlling circuit according to a first embodiment of the present invention;
FIG. 8 is a block diagram of a half-tone controlling circuit according to a second embodiment of the present invention; and
FIGS. 9 and 10 are graphs representing the effective voltage-to-lightness or intensity characteristics of each of R-, G- and B-pixels.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 shows a liquid crystal display controlling apparatus according to one embodiment of the present invention. Half-tone signal generators for red, green and blue are indicated at 241, 242 and 243 respectively, and half-tone signals for red, green and blue are indicated at 251, 252 and 253, respectively. In FIG. 1 the components appearing in FIG. 4 are indicated by the same reference numerals.
"R"-half-tone signal generator 241 will provide an "R"-half-tone signal 251 of "HIGH" at its output terminal when frame count 16 is "0", and otherwise, it will provide an "R"-half-tone signal 251 of "LOW" at its output terminal. "G"-half-tone signal generator 242 will provide a "G"-half-tone signal 252 of "HIGH" at its output terminal when frame count 16 is "2" and otherwise, it will provide a "G"-half-tone signal 252 of "LOW" at its output terminal. And, "B"-half-tone signal generator 243 will provide a "B"-half-tone signal 253 of "HIGH" at its output terminal when frame count 16 is "1", and otherwise, it will provide a "B"-half-tone signal 253 of "LOW" at its output terminal. Display controlling circuit 21 is responsive to information data 61-64 for controlling liquid crystal display data 221-223 of R, G and B as shown in Table 1.
TABLE 1______________________________________conditions of conditions of liquid crystaldisplay data 61-64 display data 221-223# 61(I) 62(R) 63(G) 64(B) 221(R) 222(G) 223(B)______________________________________0 L L L L L L L1 L L L H L L H2 L L H L L H L3 L L H H L H H4 L H L L H L L5 L H L H H L H6 L H H L H H L7 L H H H H H H8 H L L L H.T. H.T. H.T.9 H L L H H.T. H.T. H10 H L H L H.T. H H.T.11 H L H H H.T. H H12 H H L L H H.T. H.T.13 H H L H H H.T. H14 H H H L H H H.T.15 H H H H H H H______________________________________ H: HIGH L: LOW H.T.: halftone
Assume that display data 61-64 are in condition #8 in Table 1. Then, display controlling circuit 21 will output R-half-tone signal 251, which will be "HIGH" when the frame count is "0", as the R-liquid crystal display data 221; it will output G-half-tone signal 252, which will be "HIGH" when the frame count is "2", as the G-liquid crystal display data 222; and it will output B-half-tone signal 253, which will be "HIGH" when the frame count is "1", as the B-liquid crystal display data 223.
FIG. 6 shows how color liquid crystal display panel 23 responds to liquid crystal display data 221-223 in the "0"th frame, 1st frame and 2nd frame.
Now, assume that display memory 51 contains information representing the letter "A" and that the other display memories 52-54 contain nothing. In this case the binary conditions of display data 61-64 for the dots forming the letter "A" correspond to #8in Table 1. Referring to FIG. 6, the frame count 16 is "0" at the "0"th frame, and then only R-half-tone signal 251 is "HIGH", and is directed to liquid crystal display panel 23 via display controlling circuit 21, thus activating only R-pixels in the liquid crystal display panel 23. The frame count 16 is "1" in the 1st frame, and then only B-half-tone signal 253 is "HIGH", activating only B-pixels in the liquid crystal display panel 23. Likewise, the frame count 16 is "2" in the 2nd frame, and then only G-half-tone signal 252 is "HIGH", activating only G-pixels in the liquid crystal display panel 23. Thus, R-, G- and B-pixels will be selectively activated or turned on in each frame, and therefore no flickering will be caused.
In this particular embodiment, each of R-, G- and B-pixels is capable of being activated or turned on during one frame out of three frames. The present invention, however, should not be limited to this particular example. A divide-by-N (N72) counter may be used, and accordingly R-, G- and B-half-tone signal generators may be modified so that activation of selected elements is effected during one frame out of N frames. Also, it is possible that non-activation of a selected color picture element is effected during one frame out of N frames. Further, pixels can be turned on or off during M frames (M=2, 3, . . . ) out of N (7M) frames.
The activation or turning-on of one selected color picture element in one out of three frames can be attained by a decoder circuit configuration of FIG. 7, which is composed of AND circuits 30 and inverters 29. The decoder may contain additional OR circuits. Also, this can be attained by a pattern memory which is designed to be addressed by the frame count 16. In FIG. 7, R-half-tone signal generator 241 will provide a signal "HIGH" at its output terminal when the frame count 16 is "0"; G-half-tone signal generator 242 will provide a signal "HIGH" at its output terminal when the frame count 16 is "2"; and B-half-tone signal generator 243 will provide a signal "HIGH" at its output terminal when the frame count 16 is "1". These signals appearing at the output terminals of the signal generators 241, 242 and 243 are R-, G- and B- half-tone signals 251, 252 and 253. Timing according to which R-, G- and B-pixels are intermittently activated, can be controlled by changing the circuit configuration of the decoder or by changing patterns to be stored in the pattern memory.
Although the mode of operation in the display controlling circuit 21 was given in Table 1, it is to be noted that the present invention is not limited to the particular mode of operation.
FIG. 8 shows half-tone controlling circuit 14 according to the second embodiment of the present invention.
In FIG. 8 R-frame counter 151 is a divide-by-x counter (x is an integer of two or more) which is responsive to the frame signal 10 for counting frames. The signal representing R-frame count 161 is directed to R-half-tone signal generator 241. G-frame counter 152 is a divide-by-y (y is an integer of two or more, including x) counter which is responsive to the frame signal 10 for counting frames. The signal representing G-frame count 162 is directed to G-half-tone signal generator 242. Likewise, B-frame counter 153 is a divide-by-z (z is an integer of two or more, including x and y) counter which is responsive to the frame signal 10 for counting frames. The signal representing B-frame count 163 is directed to B-half-tone signal generator 243. If R-frame counter 151, G-frame counter 152 and B-frame counter 153 are the divide-by-N counters and if R-half-tone signal generator 241, G-half-tone signal generator 242 and B-half-tone signal generator 243 function in the same way as in the first embodiment, then the half-tone controlling circuit 14 of FIG. 8 functions in the same way as that of FIG. 1.
FIGS. 9 and 10 are graphs representing the relationship between effective voltage E(volts) and the lightness or intensity each of R-, G- and B-pixels.
Assume in FIG. 9 that an effective voltage E(volts) provides r 1 (cd/m 2 ) for R-pixels; g 1 (cd/m 2 for G-pixels and b 1 (cd/m 2 ) for B-pixels and that the effective voltage is E(volts) at which R-, G- and B-pixels are all in condition for "display ON". Also assume that R-, G- and B-frame counters 151, 152 and 153 are divide-by-three counters, and that R-, G- and B-half-tone signal generators 241, 242 and 243 provide "display ON" during one frame out of three frames. On simultaneous half-tone representation of R-, G- and B-pixels the effective voltage will be about 1/3 E(volts). Then, the intensity of R-pixel is r 2 (cd/m 2 ); the intensity of G-pixel is g 2 (cd/m 2 ); and the intensity of B-pixel is b 2 (cd/m 2 ). The intensity of each of R-, G- and B-pixels will not linearly vary with the effective voltage, and therefore,
r.sub.1 :g.sub.1 :b.sub.1 ≠r.sub.2 : g.sub.2 : b.sub.2.
When R-, G- and B-pixels are all in condition for "display ON", white color representation is provided, but when R-, G- and B-pixels are all in condition for half-tone representation, grey (i.e. color represented by lowering the intensity of "white") cannot be provided because of the above-noted non-linearity.
In an attempt to reduce this adverse effect, first, effective voltages for R-, G- and B-pixels to hold the equation r 1 :g 1 :b 1 =r.sub. :g 2 :b 2 are determined, and then R-, G- and B-frame counters 151, 152 and 153 in FIG. 8 and R-, G- and B-half-tone signal generators 241, 242 and 243 are modified in structure to permit application of so determined effective voltages to R-, G- and B-pixels, thereby permitting grey representation with simultaneous medium tone representations of R-, G- and B-pixels.
As seen from the above, in this particular embodiment half-tone control can be performed on each of R-, G- and B-pixels on the basis of their effective voltage-to-intensity characteristics, thus providing natural medium color representation. In place of R-frame counter 151 plus R-half-tone signal generator 241; G-frame counter 152 plus G-half-tone signal generator 242 or B-frame counter 153 plus B-half-tone signal generator 243, use may be made of a corresponding frame counter plus a pattern memory which is designed to be addressed by instantaneous count of the frame signal 10. Advantageously, this arrangement can be easily adjusted to meet the situation in which frame-thinning timing must be changed with the change of lightness characteristics which is caused by the change of frame frequency.
In this particular embodiment the half-tone display control is carried out in conformity with the lightness characteristics of each of R-, G- and B-pixels. Conversely, the lightness characteristics of each of R-, G- and B-pixels may be controlled in accordance with the half-tone display control. To attain this, the characteristics of color filters used in the liquid control display may be made to vary.
"n" kinds of half-tone display circuits for R-, G-and B-pixels (for example, two kinds of 1/3 "display ON" and 1/3 "display OFF") are prepared, and then "x (=n+2)" kinds (four kinds for the same example) of color representation are permitted, including all frames being in condition for "display ON" and all frames being in condition for "display OFF". In this case, each of R-, G- and B-pixels can have "x" (four) kinds of lightness, and therefore the possible maximum of color representations attained by combining R-, G- and B-pixels of different lightness will be equal to x 3 (64 for the same example).
A liquid crystal display panel itself can be equipped with such half-tone producing circuit to provide a multi-color liquid crystal display panel. That is, a half-tone producing circuit or controlling apparatus is built in the color liquid crystal display panel. Digital or analog interface may be equally used for the data interface. For instance, in case of the use of analog interface, a digital-to-analog converter may be used to convert digital data from the display memories to R-, G-and B-analog signals before outputting to the liquid crystal panel. The analog-to-digital converters associated with the color liquid crystal display panel convert each of R-, G- and B-analog signals to respective digital signals, which are used to operate the half-tone producing circuit for visual multi-color representation.
As described above, each dot may be made up by N pixels, a for example, a R-pixel, G-pixel and a B-pixel, and each different pixel is activated at a selected frame, and therefore little or no flickering is caused.
R-pixel, G-pixel and B-pixel are activated by selected effective voltages, each determined to be appropriate for the effective voltage-to-lightness characteristics of each pixel.
The half-tone controlling circuit can be made simple by using the filters whose lightness characters are determined on the basis of the frame-thinning rate, and accordingly the cost of the half-tone controlling circuit can be reduced.
Liquid crystal display panels may be equipped with half-tone controlling circuits, each of which is designed to be most appropriate for the characteristics of the associated display panel. This makes it unnecessary to modify the half-tone controlling circuit of the system to meet the characteristics of a new display panel.
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A half-tone color representation system suitable for use with a multi-color liquid crystal display panel, each display dot of which is constituted by three primary color pixels. More than eight different colors are represented with the three primary color pixels by providing a "half-tone" state of a pixel which is realized through successive ON-OFF controlling of the pixel. Flicker in the half-tone color representation of the display dot is reduced by causing the patterns or timings of successive ON-OFF controlling of the three primary color pixels to be different from one another.
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FIELD OF THE INVENTION
Applicants' invention relates to aircraft window shades, more specifically to a control system which ensures consistent window shade movement speed among a series of aircraft windows.
BACKGROUND OF THE INVENTION
Presently, aircraft windows are provided in modular form for retrofitting existing aircraft or finishing out newly manufactured aircraft. Because of the unique demands of the aircraft's operating environment, aircraft windows must be lightweight, compact, modular, easy to assemble, durable and have few parts.
Typically, present aircraft window shades are powered by the aircraft's electrical system, or manually operated by the passenger. These shades are raised between an upper and a lower position. Many aircraft are presently fitted with shades located between an outer and an inner pane such that the aircraft passenger does not have direct access to the shade itself; raising and lowering the shade must be effected through either a control switch which engages an electric motor or, in the case of a manually operated window, a lever which is manually positioned by the passenger.
Typically the course of a flight, individual passengers will operate their own window shades so that, at any given time, each shade will be in a different position. However, there are occasions when it is desirable for the pilot or crew to simultaneously open or close all window shades in the aircraft. Electrical control of all aircraft window shades is also required if the pilot or crew operates them en masse. This may be difficult to accomplish successfully, since the pilot can only view those window shades near to his seat and not those in the remainder of the aircraft. Because of mechanical friction and those variations introduced by voltage fluctuations along the aircraft electric power buss, electrical window shades throughout the aircraft will often each operate at slightly different speeds. This being the case, a pilot acting to close or open all of the aircraft's window shades can often not be certain that other window shades in the aircraft are similarly situated to his own.
While the raising and lowering of window shades using electrical controls is known, such devices are usually much more complicated and expensive than would be tolerated in the art of aircraft window design. An example of such a device is disclosed in U.S. Pat. No. 4,706,726 (Nortoft, 1987). This patent addresses the problem of raising and lowering a window along with the separation of slat control from the operations of window shade movement. Such a device would be impractical for use with aircraft windows, since the number of parts required militates against the simplicity, reliability, and lightweight components required for aircraft.
Applicants' invention addresses, in the various embodiments of the aircraft window shade speed control illustrated, described and claimed herein, a problem heretofore either unsuccessfully or not addressed by others in the market.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a novel electric motor speed control for aircraft window shades.
It is another object of the present invention to provide for an aircraft window shade electronic speed control which can be adjusted using a single set-point element.
It is yet another object of the present invention to provide for an aircraft window shade speed regulation control which is composed of a minimal number of parts and is reliable and lightweight.
It is still another object of the present invention to provide an aircraft window shade speed regulation control which is relatively insensitive to aircraft electric power buss voltage variations.
It is another object of the present invention to provide an aircraft window shade speed regulation control which is relatively insensitive to motor current requirements as they change due to mechanical friction between the window shade its mounting or other factors.
It is yet another object of the present invention to provide an aircraft window shade speed regulation control which can be used with a multiplicity of windows so that a single operator, the pilot for example, may open or close all window shades simultaneously and reliably, even though only a single window can be viewed by the operator.
It is another object of the present invention to provide an aircraft window shade speed regulation control which is disabled by limit-sensing devices located near the upper and lower travel limits of the aircraft window shade.
In satisfaction of these and related objectives, applicants' present invention provides an aircraft window shade speed regulation control having a control module which is relatively insensitive to aircraft buss voltage variations and motor current requirements. The control module is responsive to upper and lower window shade travel limit switches, and the window shade speed of travel is adjustable using a single potentiometer to adjust the output voltage provided to the window shade drive motor.
Applicants' objectives are readily provided for in this invention, and additional objects of this invention will become apparent upon reference to the specifications and claims as more fully set forth below.
SUMMARY OF THE INVENTION
In the instant invention, applicants provide a simple, reliable, and lightweight means for window shade motor speed control in an aircraft window that can be adjusted using a single control. This control is unaffected by aircraft buss voltage variations and motor current variations over the range typically experienced in the aircraft electrical and mechanical speed. The control serves to coordinate the movement environment among all window shades throughout an aircraft.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further explained hereinafter with reference to the schematic drawings, in which:
FIG. 1 illustrates the aircraft window shade speed regulation control module of applicants' present invention connected in a simplified configuration to the window shade drive motor assembly and limit switches connected to the output of the controller module; and
FIG. 2 illustrates an embodiment of an electrical circuit used to effect the functions of the aircraft window shade speed regulation control module of applicants' present invention using output limit switches.
FIG. 3 illustrates the aircraft window shade speed regulation control module of applicants' present invention connected in a simplified configuration to the window shade drive motor assembly and limit switches connected to the input of the controller module; and
FIG. 4 illustrates an embodiment of an electrical circuit used to effect the functions of the aircraft window shade speed regulation control module of applicants' present invention using input limit switches.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As can be seen in FIG. 1, applicants' invention consists of a motor control module (500) generally connected to a motor drive assembly (510), an aircraft buss voltage source (600), a remote control switch assembly (550), and several remote control inputs, namely, an up relay brake input (400), a down relay brake input (410), an alternate remote up command input (590), and an alternate remote down command input (595). These remote connections are not necessary to the essential operation of the applicants' invention, but are shown as additions to the preferred embodiment. The single output voltage adjustment potentiometer (70) is also shown on the body of the motor control module (500).
The motor control module (500) operates in the following general manner. An aircraft buss voltage source (600) is connected between the aircraft buss positive power input (10) and aircraft buss negative power input (20) of the motor control module (500). A remote control switch assembly (550) is connected to the motor control module (500) also. Specifically, a remote control switch common junction (580) is connected directly to the control module power common output (390), the remote control down switch (560) is connected to the control module second down command terminal (380), and the remote control up switch (570) is connected to the control module second up command terminal (330). One side of the window shade drive motor (540) is connected to the control module motor common terminal (360). The other side of the window shade drive motor (540) is connected to both the upper limit switch (520) and the lower limit switch (530) at the common point of the motor limit switch terminal (535). The other side of the upper limit switch (520) is connected to the control module upper limit switch terminal (350) and the other side of the lower limit switch (620) is connected to the control module lower limit switch terminal (340).
The motor control module (500) operates as a system for aircraft window shade speed control and is interconnected with the motor drive assembly (510) and remote control switch assembly (550) in the following manner. The aircraft buss voltage source (600) provides power to the motor control module (500). If the upper limit switch (520) and the lower limit switch (530) have not been activated, aircraft power will be passed on to the window shade drive motor (540) whenever either remote control down switch (560) or remote control up switch (570) is depressed by an operator. The speed at which the aircraft window shade is raised or lowered is determined by the relative position of the output voltage adjustment potentiometer (70). If either upper limit switch (520) or lower limit switch (530) is activated by the motion of the aircraft window shade during its travel, power to the window shade drive motor will be interrupted. To stop the movement of the window shade drive motor (540) even more quickly, a shorting connection can be applied across the up relay brake input (400) and the down relay brake input (410). This action causes the motor windings of the window shade drive motor (540) to be shorted together as long as upper limit switch (520) and lower limit switch (530) have not been activated. Also, alternate remote up command input (590) and alternate remote down command input (595) can be used in the same functional manner as remote control up switch (570) and remote control down switch (560) contacts, respectively, if they are each connected to control module power common output (390) by means of a switch or other temporary shorting connector.
FIG. 2 illustrates the details of motor control module (500) construction. The unregulated aircraft buss voltage of approximately 28 volts DC (VDC) is applied to the motor control module at terminals aircraft buss positive power input (10) and aircraft buss negative power input (20). Some smoothing of the voltage occurs when regulator input smoothing capacitor (30), of a type similar to axial lead ceramic capacitor KEMET part No. C104M5U5CA, 0.1 μF, 50 V, is placed across the terminals aircraft buss positive power input (10) and aircraft buss negative power input (20). The smoothed aircraft buss voltage is now presented to the voltage regulator module (40), similar to Douglas Electronics part No. LM317T (adjustable voltage regulator). The output voltage at regulated voltage output junction (50) is set by the values used for reference voltage resistor (60), of type similar to 270 ohms, 1/4 W, 5%, and output voltage adjustment potentiometer (70), similar to BOURNS part No. 3266W-1-502, multiturn trimmer potentiometer (5 K). Voltage regulator module (40) maintains a constant reference voltage of 1.25 V across the regulated voltage output junction (50) and voltage adjustment junction (65). By physically adjusting output voltage adjustment potentiometer (70) using a screwdriver or other means, a technician may vary the steady state voltage available at regulated voltage output junction (50). Another capacitor, regulator output smoothing capacitor (80), similar to KEMET part No. C440C105M5U5CA, 1 μF, 50 V, is placed across the output voltage to smooth out variations at the regulated voltage output junction (50) caused by sudden movement of the window shade drive motor (540). Adjustment potentiometer wiper junction (75) is at the same potential as control module power common output (390). Reference voltage resistor (60) is connected to output voltage adjustment potentiometer (70) at voltage adjustment junction (65). The regulated and smoothed voltage is then passed on to the window shade drive motor (540) using up motor relay (90) and down motor relay (100).
When the remote control down switch (960) is depressed, a connection is made between remote control switch common junction (980) which is, in turn, connected to control module power common output (390), and control module second down command terminal (380). This causes current to flow through down relay coil (300) of down motor relay (100) through second down command diode (160), similar to Pioneer part No. 1N4148, causing the regulated and smoothed output voltage to pass current through relay upper coil junction (290) through down relay motor common terminal (270) to control module motor common terminal (360) and into window shade drive motor (540). If lower limit switch (530) has not been activated, current continues to pass from window shade drive motor (540) through motor limit switch terminal (535) into motor control module lower limit switch terminal (340). The motor current then passes through lower limit switch diode (130), similar to Pioneer part No. 1N4002, and on toward up relay limit switch input (200) and to up relay motor common output (210). The current then passes through down relay motor common input (250) and through down relay motor common junction (260) to control module power common output (390), thus completing the circuit. When lower limit switch (530) is activated by the movement of the aircraft window shade as it reaches the lower limit, the motor drive current flow will be interrupted, and downward movement of window shade drive motor (540) will cease. Even if the voltage at regulated voltage output junction (50) varies due to motor movement or friction between the window shade and its mounting, voltage regulator module (40) will operate to maintain the voltage at regulated voltage output junction (50) according to the formula: ##EQU1## where V out is the voltage across regulated voltage output junction (50) and control module power common output (390), V ref equals 1.25, R 2 is the value of resistance for output voltage adjustment potentiometer (70), R1 is the value of resistance for reference voltage resistor (60), and I is the current flowing from voltage regulator module (40) into voltage adjustment junction (65) (equal to approximately 100 μA). Since the current I is so small, the regulator voltage output junction (50) is maintained at a relatively constant voltage over a wide range of motor current fluctuations.
To move the window shade in an upward direction, remote control up switch (570) is depressed so as to complete a connection between control module second up command terminal (330) and remote control switch common junction (580) which is, in turn, connected to control module power common output (390). This action causes the voltage present at regulated voltage output junction (50) to be applied to up relay coil (180) of up motor relay (90), causing current to pass through up relay lower coil junction (170), through first up command diode (110), similar to Pioneer part No. 1N4148. Up motor relay (90) will then switch contacts, and the voltage present at regulated voltage output junction (50) will be applied so as to cause current to flow through up relay upper coil junction (190), through up relay limit switch input (200), and on through upper limit switch diode (140), similar to Pioneer part No. 1N4002, and out of control module upper limit switch terminal (350). The current now flows through upper limit switch (520) and into motor limit switch terminal (535). The window shade drive motor (540) is now activated by the current flowing through it and back into the motor control module (500) at control module motor common terminal (360), through down relay motor common terminal (270), down relay motor common output (280), up relay motor common input (220), up relay motor common junction (230), and on to control module power common output (390), completing the circuit. The motor will continue to operate until upper limit switch (520) is activated, which interrupts the current flow to the window shade drive motor (540), causing upward motor drive operation to cease.
As noted above, in order to stop the travel of the aircraft window shade more quickly, a shorting connection can be applied across at the up and down relay brake inputs (400) and (410). This shorts the windings of window shade drive motor (540). Of course, the shorting connection can only be applied when no regulated voltage is present across the control module lower and upper limit switch terminals (340), (350) and control module motor common terminal (360). Such a shorting connection could be applied as a mechanically delayed contact resulting from release of either remote control down switch (560) or remote control up switch (570).
Assuming that remote control switch assembly (550) is located proximate to the aircraft pilot for remote operation, a similar assembly could be located near individual passengers and connected to alternate remote up and down command input terminals (590) and (595). The necessary common connection would be made to control module power common output (390). In this case, a connection between alternate remote command input (590) and control module power common output (390) results in current passing through control module first up command terminal (320), first up command diode (110), similar to Pioneer part No. 1N4148, and up relay coil (180), causing up motor relay (90) to operate. Similarly, a connection between alternate remote down command input (595) and control module power common output (390) results in current passing through control module first down command terminal (370), first down command diode (150), similar to Pioneer part No. 1N4148, and down relay coil (300), causing down motor relay (100) to operate.
As is shown in FIG. 1, window shade drive motor (540) and upper and lower limit switches (520) and (530) can all be located in a single location, shown here as motor drive assembly (510). The aircraft voltage supply is shown also in FIG. 1 schematically as aircraft buss voltage source (600).
Turning now to FIG. 3, a more simplified version of the aircraft window shade speed regulation control system is depicted. Instead of locating the limit switches at the output of motor control module (500), upper limit switch (610) is connected in between remote control up switch (570) and control module second up command terminal (330), and lower limit switch (620) is connected between remote control down switch (560) and control module second down command terminal (380). Exteriorly, the number of parts required to implement the aircraft window shade speed regulation control system has not changed. However, instead of having to pass the full motor current through the limit switches, only the relatively small current used to drive the up and down motor relays (90) and (100) must now be passed. This allows the use of smaller contacts within the limit switches themselves, with a resulting decrease in size of limit switches necessary to implement the aircraft window shade speed regulation control system. Also, only two wires need to be run out to window shade drive motor (540), instead of three.
Turning now to FIG. 4, it can be seen that operation of remote control down switch (560) effects a connection between remote control switch common junction (580) which, in turn, is connected to control module power common output (390) and control module second down command terminal (380). This will cause down motor relay (100) to be activated as current flows from regulated voltage output junction (50) through down relay lower coil junction (310) and second down command diode (160), similar to Pioneer part No. 1N4148. The current will also flow from down relay upper coil junction (290), through down relay motor common terminal (270) (after the contacts have switched) and out of control module motor common terminal (360) to window shade drive motor (540). The current will continue to flow into control module lower limit switch terminal (340), through lower limit switch diode (130), similar to Pioneer part No. 1N4002, through up relay limit switch input (200), through down relay motor common input (250), through down relay motor common junction (260), and on to control module power common output (390). The window shade drive motor (540) will remain active until lower limit switch (620) is activated, which causes the current flow to be interrupted to window shade drive motor (540) and downward movement of the window shade to cease.
In a similar fashion, activation of remote control up switch (570) causes a connection to be made between remote control switch common junction (580) which, in turn, is connected to control module power common output (390), and control module second up command terminal (330). This results in the activation of up motor relay (90) because voltage present at regulator voltage output junction (50) causes current to flow through up relay lower coil junction (170), through second up command diode (120), similar to Pioneer part No. 1N4148, out of control module second up command terminal (330), through remote control switch assembly (550), and into control module power common output (390). This causes the voltage present at regulated voltage output junction (50) to produce a current which flows from up relay upper coil junction (190), through up relay limit switch input (200), out of control module lower limit switch terminal (340), and into window shade drive motor (540). When the window shade drive motor (540) is activated, current continues to flow into control module motor common terminal (360), through up relay motor common input (220), through up relay motor common junction (230), and back to control module power common output (390), completing the circuit. The window shade drive motor (540) will remain active until upper limit switch (610) is activated, causing an interruption of the current flow to window shade drive motor (540). As mentioned above, a shorting connection can also be applied in this case at up and down relay brake inputs (400) and (410) to cause window shade drive motor (540) to stop more quickly. Even through passenger switch operating connections are not shown in FIG. 3, they may be applied as described in FIG. 1.
Terms such as "left," "right," "up," "down," "bottom," "top," "front," "back," "in," "out," and like are applicable to the embodiments shown and described in conjunction with the drawings. These terms are merely for purposes of description and do not necessarily apply to the position or manner in which the invention may be constructed for use.
Although the invention has been described in connection with the preferred embodiment, it is not intended to limit the invention's particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalencies that may be included in the spirit and scope of the invention as defined by the appended claims.
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An aircraft window shade speed control system which allows the coordination of window shade movement speed throughout an aircraft using a single set-point device for each window shade. Each window shade is moved by an electric motor, and its travel is limited by upper and lower limit switches. Voltage is applied to each motor by a motor control module that is relatively insensitive to variations in aircraft electric buss voltage and motor current requirements. A remote operation switch allows the pilot of the aircraft to open or close all window shades in the aircraft simultaneously, and to be assured of their ultimate position by observing only the window nearest his own position.
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INCORPORATION BY REFERENCE TO RELATED APPLICATIONS
The present application is a divisional of U.S. patent application Ser. No. 13/286,970, filed Nov. 1, 2011, which is a divisional of U.S. patent application Ser. No. 12/856,199, filed Aug. 13, 2010, now U.S. Pat. No. 8,047,666, which is a continuation of U.S. patent application Ser. No. 12/110,517, filed Apr. 28, 2008, now U.S. Pat. No. 7,780,301, which is a continuation of U.S. patent application Ser. No. 11/619,410, filed Jan. 3, 2007, now U.S. Pat. No. 7,517,100, which claims benefit of and priority to U.S. Provisional Patent Application No. 60/855,779, filed Nov. 1, 2006. The above applications are hereby incorporated by reference in their entirety and are to be considered a part of this specification.
BACKGROUND
This disclosure generally relates to convex, three dimensional mirrors and, more particularly, to a mirror, sometimes referred to as a “cross-over” or “cross-view” mirror, which affords a bus driver, for example, a school bus driver, visual access in front of, as well as alongside the bus. Such cross-over mirrors can however also be used at the rear or front corners of other vehicles such as with trucks, mail vans and the like. More specifically, the present disclosure relates to non-ellipsoidal, asymmetric cross-view mirrors which are optimized to produce more distinct images of objects located in front of or alongside a school bus or similar vehicle.
For many decades, cross-over mirrors and mirror assemblies have been deployed on school buses, and are in fact required by federal and local regulations. A substantial body of prior art has been published describing various mirrors of the type to which the present invention relates. A sample list of such prior art mirrors include U.S. Pat. Nos. 4,822,157; 4,730,914; 4,436,372; 5,084,785; D346,357; 5,589,984; 6,282,771; 6,328,450; and 6,227,674. The above list represents but a fraction of the extensive prior art on the subject of cross-over mirrors and their accessories such as mounting hardware, mirror arms and other implements by which such mirror assemblies are secured to vehicles such as busses, school buses, trucks and the like. The contents of the aforementioned United States patents are incorporated by reference herein.
The convex, three-dimensional surface of the mirror lens described, for example, in the aforementioned U.S. Pat. No. 4,436,372, terminates in a continuous, peripheral edge that lies in a 2-dimensional plane and defines, essentially, a circle. Other similar mirrors also have generally ellipsoidal or convex, i.e. dome, lens surface shapes, such that trace lines drawn over the mirror surface which pass through its center, i.e., apex, have non-constant radii of curvature.
In more recent years, the prior art has moved to provide convex, three dimensional mirror lens surfaces that have a more horizontally stretched, elongate general shapes. The aforementioned U.S. Pat. Nos. 4,822,157; 4,730,914; 4,436,372; 5,084,785; D346,357; 5,589,984; 6,282,771; 6,328,450; and 6,227,674 illustrate the general style of such mirrors.
Rosco, Inc., the assignee of the present application, has introduced to the trade a novel, stretched and elongate cross-view mirror which became known in the industry as the Rosco “oval” mirror. The aforementioned U.S. Pat. No. D346,357 and such further Rosco patents as the U.S. Pat. Nos. 6,227,674; 6,282,771 and 6,328,450 illustrate such oval mirrors. As with many of these cross-view mirrors, the oval mirrors terminate in a continuous, peripheral edge which defines the two-dimensional, elliptical, or “oval” periphery, i.e., footprint, of the mirror lens.
Other than in the last mentioned three patents of the instant assignee, the prior art three dimensional, generally ellipsoidal or convex surfaces of the aforementioned elongate cross-over mirror lenses have been characterized by radii of curvature (measured along planar cross-sections on the major and minor axes) which were distinctly non-constant, i.e. tending to increase or decrease on the mirror lens toward or adjacent its peripheral, circumferential edge.
As an example, the convex, ellipsoid mirror lens shown in U.S. Pat. No. 4,436,372 has a generally flatter, i.e. less curved, center surface, which surface curves sharper as one proceeds toward the peripheral edge. Stated differently, the “radius of curvature” of the surface decreases from the center, vertical axis (apex) of the mirror surface toward the peripheral edge of the mirror. A similar relationship is specifically claimed for the elongate, oval mirror described in the aforementioned U.S. Pat. No. 5,589,984.
But in another patent, i.e., the U.S. Pat. No. 5,084,785 to Albers, an opposite relationship is specified—the sharpest curvature, i.e., smallest radius of curvature, is at the center, and the mirror surface flattens out as one proceeds toward the peripheral edge. In other words, the mirror lens exhibits an increasing radius of curvature, along the major axis.
One school of prior art thought actually adheres to the notion that it is desirable to vary the radius of curvature, to obtain larger and less distorted images at the mirror center, and smaller, but more distorted, images, at the peripheral regions on the mirror. The idea is to increase the field of view that the mirror monitors in and around the school bus.
Further research and insight gained by the instant inventors relative to cross-view mirrors has revealed drawbacks that are still incorporated in the prior art cross-view mirrors and advantages that can be gained from improved, very careful shaping of the convex structure of the mirror lens reflecting surfaces. For example, it would be advantageous to reduce the size of the “footprint” of the mirror without reducing the field of view. A decreased mirror foot print size reduces the size of the forward looking blind spot of the mirror in front of the vehicle, improves the mirror's aerodynamic performance, the aesthetics of the vehicle, and also results in reduced mirror weight and reduced cost of mounting the mirror assembly to a vehicle. Alternatively, the size may be maintained as in the prior art, while obtaining the benefit of increased image sizes, particularly of students standing several feet in front of and far away adjacent the rear wheels of the school bus.
Furthermore, in general, a cross-view mirror is intended to provide a field of view both in front and alongside the bus. However, the size and general shape of the monitored area in front of a school bus, differs from that which needs to be monitored alongside the bus. That is, school buses and similar vehicles have comparative lengths several times larger than the widths of the vehicles. The image of a child standing alongside a school bus near the rear wheels needs to be sufficiently large to afford the driver a good view of a child who may stoop low or fallen or slipped under or too close to the school bus. At the front of the bus, it is more important to assure that the entire width and several feet in front of the bus are clearly visible. In other words, the field of view characteristics in front of the school bus and alongside differ from one another. Prior art mirrors have not been optimized to fully accommodate these differences.
Rather, all prior art mirrors, including those that have horizontally stretched bodies, are widthwise symmetrical with respect to their generally vertical mounting axis. Thus, the mirror surface size and shape and field of view to the right of the axis is identical to the mirror surface and view to the left of the axis. Therefore, both sides of the lens provide the same image reflecting characteristics at the left mirror side, which is primarily focused on the area in front of the bus, as at the right mirror side which focuses images from alongside the bus (for a mirror mounted to the right of the driver).
Another concern of the instant inventors is based on the understanding that prior art mirrors, such as the mirrors described in the aforementioned U.S. Pat. Nos. 5,589,984 and 4,436,372, have varying radii of curvature resulting in continually changing image sizes, along the surfaces of the mirror. This makes it more difficult for the driver to follow and carefully monitor the movements of a child alongside or in front of the school bus.
SUMMARY
It is an object of the present invention to overcome the aforementioned drawbacks of the prior art and to provide cross-view mirror lenses which generally increase the sizes and improve the definitions of images of children milling about either the front or alongside regions of the school bus. The features of the mirror or mirrors described below are not “required,” but are rather characteristics that may be part of the novel mirror, the exact features and combination of elements being defined by the claims and not by this section of the disclosure.
The foregoing and other objects of the present disclosure are realized by a mirror lens that has a near circular peripheral edge, but, more precisely, a slightly stretched, oblong body characterized in that the right side of the mirror lens, relative to the vertical mounting axis (or the upper peak) of the mirror, has a substantially constant first radius of curvature, and a second substantially constant radius of curvature to the left side of the vertical axis. At the small region in and around the vertical axis, there is a small section of a constant or (optionally) very slightly changing radius of curvature. These regions of constant curvature are bridged by narrow strips of changing curvature mirror surfaces, producing a smoothly changing image size which does not distract or confuse the driver, as an image of a child passes from the right side to the left side of the mirror lens.
The convex, asymmetric lens surface shape of the mirror lens terminates in a peripheral edge which lies in a flat plane and which defines in that flat plane a closed curve which has a width and a height dimension, where the width dimension is measured along an x-axis and the height along a y-axis. The x-axis extends from the right to the left side of the mirror lens and represents the farthest aspect points on the right and left sides of the mirror. The y-axis extends from the bottom of the mirror to the top of the mirror, including its furthest apart points along the height of the mirror.
The characteristics of the convex lens are such that the distance from the y-axis to the right edge of the mirror (at the peripheral edge) is not equal to the distance from the y-axis to the left edge of the mirror, producing an asymmetric lens surface, unlike any lens surface of the prior art. Similarly, the mirror is asymmetric in the vertical direction, whereby the distance from the x-axis to the bottom edge of the mirror is different from the distance from the x-axis to the top edge of the mirror along the height direction. Optionally, the effect along the height direction is such that images which are reflected from higher elevations, such as the horizon around the bus and the flashing lights of the school bus, are rendered in smaller size, as they are less important than the images that are located closer to the ground, where the images of children milling about the bus need to be clearly discerned.
In the above described mirror lens, the radius of curvature along the x-axis (on the lens surface) is smallest at the center of the mirror lens, intermediate in value to the left of the y-axis, adjacent the perimetral edge, and largest to the right of the y-axis adjacent the perimetral edge. Each of these regions has a constant radius of curvature. These regions are joined by sections where the radius of curvature changes step-wise, to bridge the different regions of constant radii of curvature.
Proceeding vertically, the mirror lens similarly has three, sequentially constant sections of radii of curvature, which are optionally joined by regions of step-wise changing radii of curvature. In accordance with one embodiment, the radius of curvature at the top of the mirror along the y-axis is substantially smaller than the other radii of curvature, to obtain a mirror of substantially reduced height and footprint.
In accordance with other optional features of the present disclosure the peripheral shape of the mirror does not conform to any prior art shape, as the shape of the mirror's periphery need not be circular, nor oval, nor symmetric, nor conform to any known geometric shape. For example, the periphery, i.e. the closed circumference of the base, may consist of sections of constant curvature arcs that are tangent to each other. In one embodiment, there may be six sections of constant curvature and two sections that have quadratic Bezier curve characteristics. The mirror may have a peak defining its upper apogee, and a more “squat” shape at the bottom (on the opposite side of the x-axis).
As another option, the mirror may include a marking visually indicating its peak, namely apogee, and its apex, i.e., the highest point of its dome over the base, thereby assisting or enabling the driver to horizontally align the mirror. The marking can be in the form of darker tinting applied to the mirror at those locations. In addition the mirror may be tinted to reduce glare, preferably along the upper one-third horizontal sector along the y-axis. The tinting may also be applied as a strip of tint extending down along the y-axis, reaching as far down as about two-thirds of the mirror surface. The strip's width may be such that a majority of the image of the bus in the mirror is covered by darker tinting, to further improve the mirror vis-a-vis its sun or headlight glare characteristics.
Still further, the swivel ball stem typically provided at the rear back of the mirror is aligned with the horizontal geometric center of the mirror vertically down from the peak of the mirror approximately two-thirds of the way down.
Other features and advantages of the present invention will become apparent from the following description of the invention that refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a line drawing of the footprint or base of the inventive mirror lens, defining various sections of different radii of curvature on the lens surface thereof.
FIGS. 1 a 1 and 1 a 2 are cross-sections through the x-axis indicating different, but constant radii of curvature along the width of the mirror lens, with bridging regions therebetween.
FIGS. 1 b 1 and 1 b 2 are a cross-sections through the y-axis of the mirror lens showing different, but constant radii of curvature therealong.
FIG. 2 is a top view of a portion of a school bus with a mapping of the field of view of the inventive lens relative to the prior art.
FIG. 3 is a second embodiment of the invention with a modified footprint.
FIGS. 3 a 1 and 3 a 2 are cross-sections along the x-axis.
FIGS. 3 b 1 and 3 b 2 are cross-sections along the y-axis of the mirror lens of FIG. 3 .
FIG. 4A is a perspective of a school bus showing a pair of cross-view mirrors mounted thereon and objects to be viewed.
FIG. 4B is a top view of FIG. 4A .
FIG. 4C is a side view of FIG. 4A .
FIG. 5 illustrates actual images seen in the inventive mirror of the disclosure and comparisons of those images to prior art corresponding images.
FIG. 6 identifies the peak and apogee on the mirror surface of the mirror of FIG. 1 .
FIG. 7 shows regions on the mirror of FIG. 1 where tinting has been applied.
FIG. 7 a is a side view of the mirror of FIG. 7 .
FIG. 8 shows the base perimeter of the mirror of FIG. 1 , with the nature of the curvature profile thereof.
FIGS. 9 a -9 c are illustrations of a construction of a lens in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
With reference to the drawings, the features of and a method for constructing the lens for the present disclosure, which is intended to be known as the EYEMAX mirror lens, are described below.
Construction is based on a multiple, (three) constant radii profile. The same profile is revolved three times to create three sections (slices) with different curvatures, each slice being characterized by a distinct radius of revolution. These sections are joined by intermediate sections that are characterized by having step-wise changing radii of curvature.
The first “slice” is created by revolving an identical profile about a given radius, e.g., R5.00″, denoting a constant radius of curvature of five inches, as shown in FIG. 9 a.
The second “slice” is created by revolving an identical profile about a radius R10.00″, as shown in FIG. 9 b.
The third “slice” is created by revolving an identical profile about a radius R8.00″, as shown in FIG. 9 c.
All three “slices” (shown above in different shades) are joined (by the regions of changing curvature) to form a single body (dome), featuring a continuous smooth surface. Each “slice” has a different purpose as far as the field of vision (i.e., field of view) is concerned.
With reference to FIG. 1 , the mirror 10 has a width, measured along the x-axis 12 , of approximately 11.39 inches. The mirror is slightly asymmetrical with respect to the y-axis 14 . For example, the right side may measure 5.86 inches in width and the left side 5.53 inches.
Proceeding along the height (y-axis), the mirror lens has a dimension of about 10.05 inches, with a top portion (above the x-axis) measuring 5.39 inches and a bottom portion measuring 4.66 inches.
Taking cross-sectional views along the x-axis 12 , the mirror has several sections of different radii of curvature along the x-axis. Proceeding from left to right, a first section 16 has a radius of curvature of 8 inches, a central section 20 has a radius of curvature of 5 inches and a right side section 18 has a radius of curvature of 10 inches.
A left joining section 22 has radii of curvature that change, step-wise, from 8 to 5 inches of radius of curvature, in incremental steps, for example, every tenth of an inch along the x-axis. Similarly, the joining section 24 has radii of curvature that change, step-wise, from 5 to 10 inches.
As shown in FIG. 1 a 1 , the sections 16 , 22 , 20 , 24 , and 18 span along the x-axis distances that measure, respectively, 2.53, 1.53, 2.59, 1.74, and 2.64 inches. The spans or chords along the mirror surface approximately and respectively measure, 3.44, 1.66, 2.59, 1.90, and 3.43 inches, as shown in FIG. 1 a 2 . The depth of the mirror dome is 3.25 inches, as shown in FIG. 1 b 2 .
In the same vein, and referring to FIGS. 1 b 1 and 1 b 2 , the radius of curvature along the y-axis proceeds from the bottom to the top such that a first section 3° has a radius of curvature measuring 4.50 inches, a central section 28 has a radius of curvature of 6.5 inches and the top section 26 has a radius of curvature of 5.00 inches. These sections ( 30 , 28 and 26 ) span, respectively, distances of 3.77, 3.50, and 2.43 along the base of the mirror ( FIG. 1 b 2 ), and distances of 4.88, 3.55, and 3.51 along the mirror surface ( FIG. 1 b 1 ).
It will be appreciated by one of ordinary skill in the art that these radii of curvature can be scaled up and down to create larger or smaller image sizes and their proportional, i.e., relative sizes, adjusted to a degree, without altering the purposes and functions of the various primary sections of the mirror, e.g., the bottom right, bottom left, center, upper right and upper left areas.
Turning to FIG. 2 , it will be seen that a mirror lens 10 of FIGS. 1, 1 a 1 and 1 b 1 produces an enlarged mirror coverage space 32 , i.e., field of view 32 , in front of the bus 36 relative to a mirror lens that is mounted at the right hand side of the bus (as viewed by the driver). The field of view along the front of the bus is expanded, while the field of view 34 alongside the right side of the bus, which comprises the student loading and unloading danger zone, is also expanded.
The versatility of the asymmetrical lens design of the present invention can be seen when certain parameters are changed. Referring to FIGS. 3, 3 a and 3 b , the radius of the original revolving profile has been reduced, allowing for a smaller mirror dome footprint with benefits such as reduced size image reflections from the upper, less important portions of the mirror, a lower wind drag coefficient, smaller blind spot size (behind the mirror) and other advantages previously mentioned. Although not shown, the mirror of this embodiment may also include sections of changing curvature.
Referring to FIGS. 3, 3 a 1 , 3 a 2 , 3 b 1 , and 3 b 2 , the width of the mirror lens 40 along the x-axis is now 11.29 inches, with a right hand side section measuring 5.81 inches and a left hand side section measuring 5.47 inches. The three depicted sections 42 , 44 , 46 from left to right, measure (along the base in FIGS. 3 a 1 ) 3.54, 3.86, and 3.89 inches, respectively. The section spans along the mirror surface are 4.56, 3.84, and 4.82 inches, respectively.
Height-wise (y-axis), however, the mirror lens size is reduced to 7.69 inches, with the curvature along the top section 48 reduced from a constant radius of 5 inches in FIG. 1 , to a curvature radius of 3 inches in FIG. 3 b 1 . The radius at the central section 50 is 6.5 inches and at the bottom section 52 , 4.5 inches. The curvature spans, from bottom to top, are 3.82, 1.00 and 2.87 inches, measured along the base. Along the actual mirror surface, these spans are 4.99, 1.00; and 4.33 inches, as shown in FIG. 3 b 1 . In general, the dimensional values of the radii of curvature and mirror sizes may be assumed to be individually and proportionately subject to variations on the order of about ten percent or even twenty percent.
Comparing the lens of the present disclosure with prior art lenses of similar size, for example, to oval prior art lenses (which have mirror lens profiles that are symmetrical relative to the y- and x-axes), the improved fields of view can be visually discerned as described below.
Thus, as shown in FIG. 4A , two passengers 54 , 56 are located in the vicinity of a school bus; with one person 56 standing in the passenger loading/unloading danger zone, aligned with the rear wheel axle 58 ; and another person 54 crouching in the crossing danger zone, aligned with the long axis of the bus.
These passenger locations outside the bus are illustrated in FIG. 4B from a top view of a bus. The same view is shown as a side view in FIG. 4C .
In the illustration of FIG. 5 , prior art and present cross-view mirror images are placed approximately in the same location with respect to the driver's eye point. FIG. 5 shows (simulated) images produced by the mirror lens, in which the reflections of the objects (children) in front of and alongside of the bus have a definition and size which surpasses those achieved with the prior art, while using a mirror footprint that is comparable to the prior art. Thus, the corresponding images 62 and 64 for prior art mirror lens 60 , are compared to the corresponding larger and better defined images 66 and 68 of the mirror lens 10 of the present invention.
In a further embodiment of the invention, the radii of curvature arrangement on the mirror lens can be reversed relative to the y-axis, to create a lens for the left side of the school bus, nearer the driver. That is, in the lens previously described, images of a person standing in front of the bus are seen on the left side of the mirror and those standing alongside of the bus appear in the right hand side of the mirror. For a comparable lens placed on the left side of the bus, the locations of the persons would be reversed and, therefore, so are the mirror's different radii of curvature sections.
Further characteristics of the mirror lens 10 in FIG. 1 can be discerned from FIGS. 6 and 8 , as follows. The mirror lens has a peripheral edge 102 , which lies in a flat plane with a first portion of the edge lying above the x-axis 12 and another portion below the x-axis. A peak section 76 of the peripheral edge 102 extends over a chord or curve of about 1.53 inches and has a constant radius of 4.47 inches along a peripheral edge section 112 , as shown in FIG. 8 . This section defines the “peak” or apogee of the base of the mirror lens 10 . This peak can be marked with a small dab of paint or by having a very dark tinting 77 applied to it, as shown in FIG. 6 .
The apex 82 of the mirror is at the cross section of the x- and y-axes 12 , 14 and similarly can be marked by an extra dark tinting or by a circle or square of dark paint. The markings 77 and 82 provide a vertical reference, which allows a driver or a mirror installer to ascertain visually that the mirror is horizontally aligned to maximize the image sizes. The peak of the mirror can be seen in the enlarged section 74 in FIG. 6 . In general, the shape of peripheral edge at the section 78 above the axis, is more pointed or sharply curved, as compared to the bottom section of the base, which has a more squat or flatter section 80 , as shown.
Turning to FIG. 8 , the peripheral edge can be described as having six sections of constant radii of curvature and two sections characterized by a curvature which can be defined as being quadratic Bezier curves, know, per se, to those skilled in the art. As further shown in FIG. 8 , the six constant radii of curvature sections include sections 104 and 106 , having respective radii of curvature of 5.45 inches and 5.15 inches and arc lengths of 3.68 inches and 3.69 inches, respectively. Constant radius sections 108 and 110 have respective constant radii of curvature of 5.49 inches and 6.04 inches, and respective arc length of 4.86 inches and 5.04 inches. As previously described, the peak section 112 has a constant radius of curvature, which is the sharpest, namely 4.47 inches and an arc length of about 1.53 inches. The last constant radius of curvature section 114 has a constant radius of curvature of 5.95 inches and an arc length of 1.51 inches. Joining the constant radii of curvature sections 104 and 114 , is a first quadratic Bezier curve 116 , which extends over an arc length of 6.53 inches. A second quadratic Bezier curve 118 joins the sections 106 and 114 and has an arc length of 6.80 inches, as shown. In the foregoing description, it should be recognized that the numerical values given are merely nominal and that the same can be adjusted and/or scaled individually and/or proportionately at least by an amount of plus or minus ten or even twenty percent.
As shown in FIG. 7 , the approximately one-third section above the x-axis 12 of the mirror can be treated with a dark tint 100 , which includes a section 101 of tinting that extends down along the y-axis 14 with the upper tinting section having generally flat horizontal bottom borders. The overall shape of the this tinting allows instant visual aligning of the mirror, both horizontally and vertically, by being able to generally note the size of the tinting along the y-axis. The location and alignment of the stem illustrated by hatched circle 94 relative to the mirror back is of some import. That is, the stem is located slightly to the right of the x-axis 12 and about two-thirds down the y-axis 14 , along a vertical line 96 spaced away from the x-axis 14 by a distance 98 . In addition, the shape of the tinting generally covers areas on the mirror which show the horizon around the bus and the center of the bus itself, where obviously children will not be seen, as can be appreciated by viewing the images in FIG. 5 . Indeed, the tinting section 101 can be more cone-shaped with the base of the cone adjoining the section 100 and the section 101 being treated with even darker tinting than the remainder of the tinted section 100 .
Referring to FIG. 7A , which shows a side view of FIG. 7 , it will be noted that the mirror lens 10 is affixed at its peripheral edge to a mirror back 88 , including by means of a gasket 84 . The mirror back 88 has a swivel ball joint 90 , which supports a stem 92 which can be connected to the arm assembly shown, for example, in FIG. 4A . A draining hole 86 is provided at the bottom of the mirror and will typically drain the mirror, particularly since the mirror is usually mounted with the top tilted away from the vertical toward the driver's eyes. The location of the swivel provides greater flexibility in adjusting, both vertically and horizontally, the lower half of the mirror, where the most important images (of children) are expected to be viewed.
As noted, one of ordinary skill in the art will now recognize that the instant inventors have appreciated and disclosed herein the advantages which ensue from providing a mirror of constant radii of curvature which are joined and smoothly blended with one another over short distances to provide continuous and distinctive images, without suffering the distortions in images that are encountered with mirrors of the prior art that have varying radii of curvature throughout, including in the sections closer to the perimetral edges where the images of students milling about the school bus are typically observed.
Optionally, the top one-third surface of the mirror surface may be roughened or scored or otherwise treated to blur images reflected from the top of the mirror lens, so as to concentrate the driver's attention to images reflected from the ground where children might be present.
The mirror lens of the present invention has the usual flat rear support panel to which the lens is fixed by glue and a gasket which conceals the joint between the mirror back and the mirror lens. In addition, the mirror back includes a structure which can be attached to an arm assembly 70 , such that the arm assembly can, in turn, be anchored in a mounting base 72 that is securely affixable to the vehicle fender, such as a school bus. See FIG. 4A .
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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An asymmetrical mirror lens, usable on front fenders of school buses and similar vehicles, which has a plurality of mirror sections, each having a distinct constant radius of curvature to reduce image distortion. Optional sections located between sections of the constant radius of curvature have a step-wise changing radii of curvature to smooth the image sizes as an object moves across the mirror lens.
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This application is based on Provisional Application Ser. No. 60/001,172 filed Jul. 14, 1995, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to a control system for an automatically tuned fretted stringed instrument adapted for use with a capo installed.
BACKGROUND OF THE INVENTION
Manually tuning a musical instrument can be a difficult and tedious process, usually requiring a considerable amount of time and skill. Although having an automatic tuning system is desirable for ease and convenience, as well as for accuracy, there is another important reason. Frequently, a musician will need to change the tuning of an instrument during a performance or an instrument will go out of tune during a performance. And, during this process, it may be necessary to compensate for a change in an instrument's characteristics. For example, during a performance with a guitar, a musician may install a capo between selections. A capo is a device for clamping all strings to a particular fret, thereby increasing the frequencies of all strings by a constant factor. Because of the time required, manually retuning an instrument during a performance is usually unacceptable. One common, although expensive and inconvenient, solution to this problem is to have properly tuned spare instruments available for such occasions. A much better solution is to have a system for automatically tuning an instrument within a length of time short enough to be unnoticed by an audience.
Many different types of automatic tuning systems have been devised. There are open-loop systems which drive a tuning actuator to a predetermined position for each desired frequency. These have the advantage of being able to change tuning, silently and therefore unnoticed, during a performance. However, they have the disadvantage of being only as accurate as the predicted relationship between the frequency of the tone produced by the instrument and the actuator position.
There are closed-loop systems which measure the frequency of the tone produced by the instrument, compare it to a desired value, and use the result of the comparison to control an actuator which tunes the instrument. This technique is accurate in that it directly controls the frequency of the instrument and is independent of other factors which affect frequency. However, it has the disadvantage that an audible tone must be produced while the instrument is being tuned; and that audible tone generally precludes tuning during a performance.
Some stringed instrument systems, because of interactions between strings, sequentially tune each string and then iterate to compensate for the interactions. Others tune selected strings, or all strings, simultaneously and then iterate. These techniques require producing a tone, taking a frequency measurement, estimating and executing an actuator movement, then taking a new frequency measurement and repeating the process until the frequency produced is sufficiently close to the desired frequency.
Other systems measure the tension of (actually, the force applied to) a string and compare the measured value with a desired value to produce an actuator control signal. Although the string tension method does not require a tone to be produced while tuning, it does require a known and stable relationship between string tension and frequency. Satisfying this relationship requirement is difficult because frequency also depends on string length and mass per unit length as well as other factors.
A typical stringed musical instrument has a semi-rigid structure which changes form slightly when string tensions in the instrument are adjusted during tuning. A change in form due to the adjustment of one string therefore affects the frequencies of the remaining strings. Temperature and humidity also affect the form, and the frequencies, of the instrument in more subtle ways.
A system which compensates for the effect of adjusting one string on the frequencies of the remaining strings, described in U.S. Pat. Nos. 4,803,908 and 4,909,126 to Skinn et al., which are incorporated by reference herein in their entirety, involves the use of a calibration function which relates the position of each actuator to the frequencies produced by all the instrument's strings. Creating the calibration function involves the measurement of frequencies at multiple positions of each actuator and, through regression techniques, relating the position of each actuator to not only the frequency of its own string but to the frequencies of the other strings as well. The use of regression techniques provides the advantage that a priori knowledge of the detailed characteristics of the instrument being tuned is not required. Also, the calibration function can be updated by recalibration as the instrument ages, or as environmental or other changes occur. Using a calibration function generated from the particular instrument being tuned permits open-loop, and therefore silent, tuning with accuracy comparable to that of closed-loop systems.
In all of the previously described open-loop systems, a calibration function relates a desired frequency to an actuator position. However, if such a system is calibrated without a capo and then a capo is installed, this relationship is destroyed and the system must be recalibrated for each position of the capo. It is therefore an object of this invention to provide for automatically tuning a stringed musical instrument after installing a capo without having to recalibrate the system.
In closed-loop systems wherein the measured frequency is compared to a desired frequency, installation of a capo shifts the measured frequency relative to the desired open string frequency and thereby skews the comparison. It is therefore a further object of this invention to provide for automatic closed-loop tuning of a string instrument after installing a capo.
SUMMARY OF THE INVENTION
The invention is a control system for automatically tuning a stringed musical instrument with a capo installed, using an original calibration function or tuning system for the instrument without the capo. The control system uses a capo scale factor to scale the frequencies measured with the capo installed in order to obtain the frequencies that would have been produced without a capo. The control system enables a musician to quickly tune an instrument after installing a capo, in a manner unlikely to be noticed by an audience.
When a capo is installed on an instrument, the vibrating portion of every string is ideally shortened by the same amount and the frequency of every string increases by the same factor. This factor is a function of the position of the capo along the string. For the case where the capo is clamped on a fret and there are 12 frets per octave, the frequencies each increase by 2.sup.(n/12), where n is the number of the fret on which the capo is installed. In both open- and closed-loop tuning systems, the measured frequencies are multiplied by a capo scale factor, which is the reciprocal of the frequency increase factor, to obtain scaled frequencies, and the scaled frequencies are used by the control system in lieu of open string frequencies. The capo position, n, can be input by the musician or determined directly by the control system.
In an open-loop system having a calibration function, the scaled frequencies are used within the original calibration function to compensate for the installation of the capo. However, in addition to the primary effect of shortening the vibrating length of the strings, the capo causes secondary effects such as changing the string tension. Thus the original calibration function requires slight adjustments to correct for secondary effects of the capo. In the preferred embodiment, the calibration function can be rapidly updated following installation of a capo.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and objects of the invention and the manner of attaining them will become more apparent and the invention itself will best be understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, a brief description of which follows.
FIG. 1 is a block diagram of an automatic tuning system utilizing this invention.
FIG. 2 is a plot of frequency versus elongation for a single string.
FIG. 3, comprising FIGS. 3A-C, shows plots of actuator position versus frequency for a single string showing "touch-up" calibrations.
DESCRIPTION OF THE PREFERRED EMBODIMENT
When reference is made to the drawings, like numerals indicate like parts and structural features in the various figures. Also, herein, the following definitions apply:
transducer: any device for providing a signal from which the frequency can be obtained;
actuator: a device for changing a frequency of the instrument in response to a control signal;
actuator position: a particular actuator output affecting frequency, such as angle, force, pressure or linear position;
calibration function: any function relating frequency and actuator position and may be represented by, and stored as, a set of coefficients for a specific mathematical expression or as values in a look-up table;
open frequency: frequency of a string without fretting by either an installed capo or manual fretting;
target frequency: a desired frequency to which a string is to be tuned, generally without fretting (i.e., target open frequency);
tuning configuration: a group of target frequencies (one per string) which comprise a particular target tuning of an instrument;
cents: a measure of frequency in which 100 cents equal one half-step; i.e., 1200 cents equal one octave; and
wherein the terms frequency and period are regarded as equally unambiguous measures of frequency.
The invention is a control system for automatically tuning a stringed musical instrument with a capo installed, using an original calibration function or tuning system for the instrument without the capo.
When a capo is installed on a stringed instrument such as a guitar, the open frequency f open of a string is changed to a new frequency f capo as predicted by the following equation: ##EQU1## where n is the number of the fret, relative to the nut, on which the capo is clamped. When no capo is installed, n=0. This equation assumes 12 frets per octave. For other intervals it can be modified accordingly. The relationship between the open and the capoed frequency can be used to scale a measured frequency, f meas , in order for the processor to use the scaled frequency f s to generate control signals. The measured and scaled frequencies are related by a capo scale factor according to:
f.sub.s =2.sup.-(n/12) f.sub.meas.
Scaling the measure frequencies in this way essentially "tricks" the processor into tuning the instrument as if there were no capo installed. The scaled frequencies used by the processor imitate the open frequencies which would have been obtained in the absence of the capo.
Detecting an installed capo can be done automatically by the processor by comparing the measured frequency to the target open frequency. If the ratio is not unity, n can be determined and the matching capo scale factor can be applied to the measured frequency. If the ratio yields an non-integer value of n, the nearest integer is selected. The ratio can be measured for more than one string and the average used to determine the capo position. The instrument can also be equipped with a capo sensor which, for example, detects electrical contact between a string and a fret. The scaling can also be selected manually by the user through an operator interface. The user can specify on which fret a capo is installed or can indicate the installation of a capo and allow the processor to determine n.
A functional block diagram of the control system and its connection to other elements of the tuning system is shown in FIG. 1. Transducer 10 is coupled to processor 50 which is in turn connected to actuator 90. Operator interface 70 and memory 60 are also connected to processor 50. Transducer 10 produces an electrical signal representing a sound produced by the instrument (not shown).
Transducer 10 is any device for providing a signal from which the frequency can be obtained. Examples of transducers include devices sensitive to sound waves such as microphones, magnetic or electric field sensing devices coupled to vibrating elements of an instrument, optical sensors coupled to vibrating elements, and transducers sensitive to frequency-related phenomena such as strain gauges measuring tension in strings of stringed instruments. The term transducer is used in the singular to refer to one or a plurality of devices coupled to the strings. Depending on the particular transducer, the coupling to the strings can be, for example, mechanical, electrical, optical, through sound waves, or through a magnetic field.
The transducer signal can be conditioned for use by processor 50, for example by Schmitt triggers which convert an analog signal into a binary signal and prevent edge slivers in the binary signal. Other devices for conditioning a frequency signal for use by a processor include amplifiers, buffers, comparators, filters, and various forms of time delays and voltage level shifting. The signal conditioning elements can be incorporated in the processor or in the transducer.
Processor 50 includes a means for obtaining the frequency of each string from the transducer signal. Frequency measuring techniques include timers measuring the periods of signals, such as digital counters implemented in either hardware or software, and digital counters counting the number of cycles of a signal in a period of time. Other techniques include the use of Fourier transforms or other processing algorithms, analog or digital filters, and digital signal processors.
The processor includes a means for outputting control signals to actuators connected to the instrument's strings. There are many types of actuators adaptable to tuning an instrument, including electromechanical devices such as stepper motors, servo motors, linear motors, gear motors, leadscrew motors, piezoelectric drivers, shape memory metal motors, and various magnetic devices. Position reference devices for actuators include electrical contacts, optical encoders and flags, potentiometers, and mechanical stops for stepper motors. Many other types of apparatus will be obvious to those skilled in the art of control systems. A preferred embodiment includes the choice of an actuator which holds its position when power is removed; for example, a stepper motor or a gear ratio, leadscrew pitch, lever arm, or ramp with a critical angle such that if the motor produces no torque the tuning does not change. The motors can be connected to the strings by directly attaching a string to a motor shaft, or by various mechanical systems utilizing components such as gears, pulleys, springs and levers. The actuator can change the tension on the string by pulling along the axis of the string or by transverse deflection of the string. Many mechanical actuators for altering string tension have been described in the art. The control system of the present invention can be employed with any actuator. Each string can have more than one actuator attached to it, for example for coarse and fine control of the string frequency.
Various techniques for interconnecting functional blocks are also available to those skilled in the art. In addition to the usual wired connections are optical, ultrasonic, and radio links which permit remote location of portions of the tuning system.
The operation of the control system of this invention is described below, first for a closed-loop system and then for an open-loop system.
In the closed-loop tuning system of this invention, processor 50 obtains a transducer signal from transducer 10 and used it to obtain the measured frequency of each string. Either automatically or by instructions from operator interface 70, processor 50 decides if scaling of the frequencies is necessary. If so, the measured frequency is scaled by the capo scale factor, and processor 50 uses the difference between the scaled frequency and the target open frequency for each string to generate an error signal. A control signal is generated from the error signal and is output to actuator 90. The actuator then moves to reduce the error signal to zero. In order to be able to change tuning configurations in the middle of a song without strumming and waiting for the servos to retune, the closed-loop system can be used before the performance to generate a look-up table of actuator positions for each tuning configuration. A closed loop system can also be used to generate a mathematical calibration function. The details of the implementation of a closed-loop (servo) system providing the function described are readily available in textbooks and catalogs and are familiar to those skilled in the art of control systems.
The open-loop system using a calibration function also uses the scaled frequencies to generate control signals. A calibration function is any function relating frequency to actuator position. In a preferred embodiment a single calibration function can be used to access a plurality of tuning configurations, and the instrument can switch between tuning configurations in the middle of a song without the need for additional tuning. A detailed description of the general calibration function is given first before describing the modification of the calibration function for use with an installed capo.
When tuning the instrument in the open-loop system, processor 50 obtains a calibration function from memory 60 and utilizes it to generate, from a set of target frequencies, control signals which are utilized by actuator 90 to tune the instrument. For a control system to automatically tune all of the strings of an instrument without iteration, the use of empirically derived calibration functions is nearly always necessary. The vibrating frequency of a guitar string depends not only on the position of the actuator controlling the tension in that string but also on the effective length and mass of that string, the tension in all the other strings, the stiffness of the neck of a guitar, etc. The combined effects of these variables on frequency are extremely difficult to predict and therefore the preferred control system has the ability to generate a calibration function of empirically determined shape.
A calibration function can have any form which relates actuator position to frequency for the instrument being tuned. For example, a simple model relating elongation and frequency of a vibrating string is plotted in FIG. 2 and described by the equation: ##EQU2## where y is the elongation, M is the mass per unit area, L is the length, E is the modulus of elasticity, A is the cross sectional area, and f is the frequency of the string. However, this expression only includes string attributes. Where the elongation y of a string is produced by an actuator, additional system related factors become involved and the relationship between actuator position and frequency is usually considerably more complex than indicated by this simple function. Furthermore, the values of the string attributes themselves are difficult to know precisely due to manufacturing tolerances. It is therefore important to have a system for producing calibration functions with as many terms as necessary to adequately describe the characteristics of the instrument.
Any general (continuous, single valued, etc.) function g(x) can be represented by the Maclaurin series in the following equation: ##EQU3## By recognizing that g(x) and its derivatives g.sup.(n) (x) are constants for x=0 and substituting f for x and x for g(x) the function can be rewritten as:
x=a+bf+cf.sup.2 +df.sup.3 +. . . (2)
which relates actuator position x to vibrating string frequency f. Each different set of coefficients a, b, c, . . . , produces a different function. The use of the Maclaurin series permits calibration functions to be defined and stored as sets of coefficients.
Although Eq. 2 in its most general form is an infinite series, most calibration functions are relatively simple and only a few terms are needed to obtain the accuracy required. For example, in the preceding model described by Eq. 1, only the third (f 2 ) term is required. In the preferred embodiment, the values of coefficients a, b, c, etc., of the calibration function are empirically obtained by a calibration process. In the calibration process, a minimum number n of frequencies f i , where 1≦i≦n and n is the number of unknown coefficients, are measured at n different actuator positions x i . Then each pair of values, x i and f i , is sequentially inserted into Eq. 2, resulting in n equations with n unknowns which can be solved by conventional techniques for the unknown values of the coefficients. The number n is the minimum number of measurements necessary to solve for the coefficients; more measurements may be needed to obtain statistically valid values for f i if the measurements are not repeatable.
After the coefficients in Eq. 2 have been determined by the calibration process, an actuator position x can be computed for any given target frequency f within the tuning range of the instrument. Then, the value x can be used to control the actuator and tune the instrument to the frequency f. In obtaining a calibration function f is the measured frequency at a selected actuator position; when using the calibration function f is a selected target frequency used to estimate the necessary actuator position.
Since the calibration function has as many empirically derived terms as necessary to accurately describe the characteristics of the instrument, it can predict an actuator position which will yield the target frequency within a few cents over the entire tuning range of the instrument. However, as an option providing greater accuracy, the following "touch-up" calibration yields the target frequency within ±2 cents.
In the event that the instrument's characteristics change slightly after the initial calibration and all tuning configurations are affected, or if the frequency produced by the instrument for a particular tuning configuration is incorrect, the calibration can be modified or "touched up" by the following methods.
Referring to FIG. 3A, curve 100 represents the original system characteristic function, described by the calibration function, and curve 101 represents a new (changed) characteristic function. In this example, curve 101 is a simple translation in actuator position x of curve 100 representing, for example, a slip in the position of a tuning peg or the stretching of a string. During touch-up, the actuator is driven in a normal tuning operation to a position x 1 corresponding to a target frequency f 1 indicated by point 103 on curve 100. The instrument is strummed once and the actual frequency, f 2 is measured. On the new characteristic function, curve 101, frequency f 2 corresponds to point 104. Using the original calibration function, actuator position x 2 is computed from the measured frequency f 2 as indicated by point 105. The difference between the two values of actuator position x 2 -x 1 =ε is computed. This value of ε is used to modify the constant term a in Eq. 2 and therefore affects the computed actuator position for all tunings thereafter. Modifying the constant term in Eq. 2 translates original calibration function 100 vertically upward by the value ε, as indicated by arrow 107, to create a new calibration curve which, in this example, corresponds to new characteristic function 101. Using the new calibration function, to achieve target frequency f 1 the calculated actuator position is x 3 , as shown by point 106. In a preferred embodiment ε is obtained for "Standard Tuning" (EADGBE). However, it can alternatively be obtained in a different tuning configuration. In the case when the frequency of only a particular tuning configuration is incorrect, the value of ε is measured and stored for that tuning configuration.
Generally changes in the system calibration are more complex than the simple shift shown in FIG. 3A. Referring to FIG. 3B, curve 100 again represents the original system characteristic function, described by the calibration function, but curve 102 represents another new (changed) system characteristic function. In this case, the new function is not a translation of the original function but is a function having a different curvature. Such a change in the function could be the result of a change in the stiffness of the structure of the instrument, for example. The touch-up in this case can be performed in the same way as in the previous case, that is by translating curve 100 vertically upward, as indicated by arrow 108, to superimpose on curve 102 at point 104. The result is curve 111. This touch-up is accurate only in the neighborhood of the point 104 since curve 111 deviates from curve 102 as the distance from point 104 increases. Using new calibration curve 111, to achieve target frequency f 1 the calculated actuator position is x 3 , as indicated by point 106. Note that point 106 does not fall exactly on new system characteristic function 102, and so the actual touched-up frequency differs slightly from the target frequency.
An alternative method of touching-up the calibration is shown in FIG. 3C. Again, curve 100 is the original characteristic function and curve 102 is the new characteristic function. The target frequency is f 1 , but the frequency actually obtained is f 2 . Instead of computing a position x 2 from the frequency f 2 , the difference between the actual and the target frequencies δ=f 2 -f 1 is computed and stored during the touch-up. New calibration curve 112 is formed by translating curve 100 horizontally to the left by the value δ as indicated by the arrow 110. The result is indicated by the curve 112. Using new calibration curve 112, to achieve target frequency f 1 the calculated actuator position is x 4 , as indicated by point 109. Note that point 109 does not fall exactly on new system characteristic function 102. The relative accuracy obtained by sliding the calibration function curve horizontally compared to vertically depends on the shape of the changed system characteristic curve (e.g., curve 101 versus curve 102). Both methods provide excellent tuning accuracy. In general, the calibration function is modified based on the difference δ between the measured and target frequencies (f 2 -f 1 ) or the difference ε between the corresponding actuator positions (x 2 -x 1 ). A combination of horizontal and vertical translations can also be used.
Although a linear approximation can be used for touch-up, the preceding methods provide greater accuracy because the calibration function itself, instead of a linear approximation, is used to compute the value of ε or δ. Since a calibration function is in general non-linear, the combination of using the calibration function itself and evaluating it at a point already very close to the desired position provides a way of obtaining a very accurate final adjustment of the calibration.
An alternative to the previously described touch-up method utilizes a servo system. In this method, the actuator is driven to the position x 1 using a calibration function as previously described. Then the instrument is strummed and the difference between the actual frequency of each string and the target frequency of that string is used to generate an error signal. A control signal is generated from the error signal and is applied to the actuator drive circuits. The actuator then moves to reduce the error signal to zero as in a traditional servo system. In this case, string interactions and other factors affecting frequency need not be considered because the frequency of each string is independently moved to its desired value by the servo system even though the instrument's characteristics may be changing. When all actuators have settled at their final positions, the resulting position values are used to modify the calibration function or stored for subsequent use in tuning the instrument. As described previously, a servo system can also be used, in lieu of a calibration function, for the primary tuning process.
The calibration function described above is adequate for a single string. However, a practical stringed instrument has multiple strings. In this case, the previously described function is expanded to include the other strings as follows: ##EQU4## where the subscripts refer to the strings and associated actuator positions.
The one-dimensional (single actuator, multiple positions) calibration procedure, described for a single string, is expanded into two dimensions (multiple actuators, multiple positions) as required for multiple strings. By storing the actuator position data x jk and the corresponding frequency data f jk for each combination of actuators j (connected to strings j) and positions k, enough independent equations to solve for the unknown coefficients can be generated. The equations can be solved by conventional techniques, including matrix, regression and statistical methods, and the resulting coefficients stored in a non-volatile memory.
The use of the Maclaurin series is a general solution which permits the synthesis of a calibration function of any form. However, if the form of the function is known in advance, e.g. Eq. 1, that function can be substituted for the series. The same kind of calibration process is performed and the task is easier with fewer terms and fewer coefficients than required for a series. Also, as another alternative, a Taylor series as in the following expression: ##EQU5## could be used in place of the Maclaurin series. In this case, the calibration function uses the difference between two frequencies, for example a target frequency and an actual frequency, instead of a single frequency, as an argument during calibration.
Although the calibration functions in the preceding descriptions are empirically derived mathematical equations, the invention may use calibration functions of many other forms. For example, the calibration functions can be based on theoretical models instead of empirical data and can be in the form of look-up tables instead of mathematical functions.
Further details of the open-loop system are given in concurrently filed U.S. application Ser. No. 08/679,080, entitled "Musical Instrument Self-Tuning System with Calibration Library" which is incorporated by reference herein in its entirety.
In the present invention the open-loop system is modified as follows. When a capo is installed the measured frequency is multiplied by the capo scale factor and the scaled frequency is used in the calibration function, as in the following example for a single string:
x=a+bf.sub.s +cf.sub.s.sup.2 +df.sub.s.sup.3 +. . . .
Indistinguishably, the coefficients b, c, d. . . . can be scaled by multiplying by appropriate powers of the capo scale factor.
An alternative method for using a capo on an automatically tuned instrument is described in the above cited concurrently filed U.S. Patent Application. It utilizes a plurality of calibration functions, including a different calibration function for each capo position. The two can also be used in combination. For example, the stored calibration functions can contain just one capo calibration function, obtained with a capo installed. To tune the instrument with a capo on a different fret, the capo calibration function can be modified with a scaling factor as described above, but in this case n is the difference in fret number between the fret on which the capo is installed and the fret on which it was installed for the capo calibration.
Utilizing the capo scale factor corrects for the first-order effects of an installed capo. However, because of slight changes in string tension, slight string bending, and other factors produced by the capo, the frequency obtained is not exactly equal to that predicted by the scaled calibration function and a modification of the calibration function is often necessary. An advantage of the present invention is that, by scaling the measured frequency, the calibration function can be modified with a single strum instead of requiring a full re-calibration procedure after installing a capo.
The modification can follow the touch-up procedure described above. In the touch-up procedure the original calibration function is used to calculate actuator positions for the target open frequencies. In these actuator positions, the actual frequencies are measured with a single strum and are scaled by the capo scale factor. The calibration function is then modified based on the difference between the scaled measured frequencies and the target open frequencies, or the difference between the corresponding actuator positions calculated by the original calibration function.
The invention has been described for use with a fretted stringed instrument. It can also be used with any non-fretted instrument which uses a capo. In a fretted instrument the capo clamps the strings at a fret and that fret effectively becomes the new nut. In a non-fretted instrument, the capo includes a metal bar against which the strings are clamped to form a new nut.
While the invention has been described above with respect to specific embodiments, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention which receives definition in the following claims.
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The invention is a control system for automatically tuning a stringed musical instrument with a capo installed, using an original calibration function or closed-loop tuning system for the instrument without the capo. The control system uses a capo scale factor which scales frequencies measured with the capo installed to what they would have been without a capo. The control system enables a musician to quickly tune an instrument after installing a capo, in a manner unlikely to be noticed by an audience.
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[0001] This is a Continuation-In-Part application of international application PCT/EP01/08957 filed Aug. 8, 2001, and claiming the priority of German application 100 42 519.4 filed Aug. 3, 2000.
BACKGROUND OF THE INVENTION
[0002] The invention resides in a biopsy device for the removal of soft tissue samples from a living organism including a housing supporting a biopsy needle with recesses in its sides near the tip of the needle, a canula which is axially movably disposed on the needle, a spring for moving the needle forwardly and a spring for moving the canula forwardly.
[0003] In human and veterinary medicine, a targeted removal of soft tissue samples from the living organisms, called biopsy, is a solid part of the diagnosis in connection with numerous health problems. Often, only the examination of a tissue sample permits a safe diagnosis. Whereas a biopsy is performed usually on body parts which are accessible from the outside by surgical instruments, endoscopic procedures must be used for biopsies on internal body parts using for example a biopsy needle. The biopsy needle, which has a recess at its side near its tip, is inserted into the tissue to be examined so that the tissue enters the recess. Then a canula is moved forwardly over the recess toward the needle tip whereby the tissue in the recess is severed and removed with the needle for examination.
[0004] There are three different types of biopsy devices. In manual biopsy devices, the needle is normally inserted and the canula is manually moved forwardly. In semiautomatic biopsy devices, the needle is manually inserted, but the canula is moved at high speed forwardly over the recess of the biopsy needle by the release of a compressed spring. Automatic biopsy devices include generally two spring force storage structures, one for the rapid forward movement of the biopsy needle into the predetermined target area and the other for the immediately following rapid forward movement of the canula.
[0005] WO96/39941 discloses an automatic biopsy device which comprises a housing with a biopsy needle and a canula supported therein so as to be axially movably disposed on the biopsy needle. It also includes for each a spring structure with a metal spring for a spring force driven forward movement of the biopsy needle and the canula. For the automatic operation, first both springs are manually compressed or tensioned, whereby two guided members, on which the biopsy needle and the canula are mounted, are retracted to an end position in which they are compressed or tensioned. Two guided members on which the biopsy needle and the canula are mounted are retracted thereby to an end position where they are held by a simple locking mechanism disposed eccentrically with respect to the canula and the biopsy needle. After the biopsy device is properly positioned, the locking mechanism for the biopsy needle is released whereby the needle is propelled by spring force toward the target area. Shortly before reaching the target area, the movement of the biopsy needle releases in the housing the locking mechanism for the canula resulting in a spring force operated advance of the canula. However, the biopsy device includes several metallic components, which are for example springs consisting of spring steel. This causes in the MRT picture distortions (artifacts) Steel springs are consequently not very suitable for use with MRT. The biopsy needle with the canula is provided in the form of a replacement unit in the housing with the two spring force storage structures.
[0006] However, if during an MRT examination a carcinoma is detected and if based on the image, a tissue sample is to be taken in the MRT, the biopsy device and the manipulator must be of such a design that no artifacts occur.
[0007] It is the object of the invention to provide a biopsy device with a spring force storage arrangement so that it is suitable for an image-based operation with an MRT in which strong magnetic fields (>1 Tesla) are present. Furthermore, the kinematics of the biopsy device should be improved so as to facilitate the replacement of the biopsy needles and canulas and to improve generally the operation of the device.
SUMMARY OF THE INVENTION
[0008] In an automatic biopsy device comprising a housing in which a biopsy needle is axially movably supported by a needle support structure and a canula extending around the needle is axially movably supported by a canula support structure and first and second spring force storage structures are provided for biasing the biopsy needle and the canula, respectively, toward an extended position and the biopsy needle and canula support structures are held in a retracted position by respective first and second releasable locking means, releasing means are provided for manually releasing the first locking means to permit the needle to be propelled by the first spring force storage structure to release the second locking structure by releasing means of the needle support structure to permit the canula to be propelled by the second spring force storage structure, the biopsy needle and canula and also the spring force storage structures consisting of a non-magnetic electrically non-conductive material.
[0009] The invention will be described in greater detail below on the basis of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a cross-sectional view of a first embodiment of the invention including two fluid spring storage structures,
[0011] [0011]FIGS. 2 a to 2 c show the charging procedure of the biopsy device shown in FIG. 1,
[0012] [0012]FIG. 3 a to FIG. 3 c show the needle and canula insertion procedure with the device according to FIG. 1,
[0013] [0013]FIG. 4 is a sectional view of a second embodiment of the biopsy device using two spiral spring force storage structures,
[0014] [0014]FIG. 5 is a sectional view of a third embodiment using two rubber tension springs as spring force storage structures,
[0015] [0015]FIG. 6 a to FIG. 6 e show, for the embodiment according to FIG. 5, a housing structure which can be opened to provide access to the interior, and
[0016] [0016]FIGS. 7 a to 7 d show another opening structure for device shown in FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] [0017]FIG. 1 shows a first embodiment of the biopsy device in a rest position that is in a position in which the springs are relaxed. It includes a housing 1 with two spring force storing structures comprising two bores 2 and 3 each including a piston 4 , 5 with seals 6 and 7 . The two bores 2 and 3 may be blind bores forming cylinder chambers. The bores 2 , 3 include above the pistons 4 and 5 a gas which may be compressed to bias the pistons 4 , 5 onto the seats 10 and 11 of the housing 1 . The bores 12 and 13 in the pistons 4 and 5 are in communication with the cylinder chambers 2 , 3 of the housing and commonly form an enlarged storage volume for the pressure medium 9 . With the relatively large pressure fluid volume, the volume change caused by a movement of the piston is relatively small so that the pressure gradient during movement of a piston 4 , 5 is also relatively small. The pistons 4 and 5 extend through the housing 1 and beyond the seats 10 and 11 and are each connected to a respective cap 14 and 15 so as to be movable therewith.
[0018] The piston 5 is provided with a projection 16 , which extends into a circumferential groove of a coupling member 17 having an axis coinciding with the axis of symmetry 8 of the device. The coupling member 17 firmly engages the biopsy needle 18 and is axially movably supported in the central bore 21 . At the end of the coupling member 17 opposite the biopsy needle 18 , there are at least two resilient webs 19 , which are provided at their upper ends with engagement hooks. At its end adjacent the biopsy needle 18 , the coupling member 17 is provided with an inwardly directed conical area 20 , which opens toward the biopsy needle 18 .
[0019] In a similar way, a projection 22 , which is connected to the piston 4 , extends into a circumferential groove formed in the rotationally symmetrical coupling member 23 , which serves as a carrier for the canula 24 and to which the canula 24 is firmly connected. Also, the coupling member 23 is axially movably supported in the bore 21 . At the end of the coupling member 23 remote from the canula, the coupling member 23 carries at least two resilient webs 25 , which are provided at their free ends with engagement hooks.
[0020] As shown in FIG. 1, the biopsy needle 18 is inserted into the canula 24 from the coupling member end thereof and is slidably supported in the canula with little or no play.
[0021] The two coupling members 17 and 23 , which are arranged in axial alignment one behind the other in the bore 21 and which are firmly connected to the biopsy needle 18 and, respectively, the canula 24 , ensure that the biopsy needle 18 as well as the canula 24 are guided accurately along the axis of symmetry 8 without any other guide elements.
[0022] In the center part of the bore 21 between the two coupling members 17 and 23 , a circumferential shoulder 26 is provided. Another circumferential shoulder 27 is at the upper end of the bore 21 . The shoulders 26 and 27 serve as engagement ledges for the locking hooks of the engagement webs 19 and, respectively, 25 , when they are in their retracted end positions in which the spring force storage devices are tensioned. The engagement webs 19 and 25 of the coupling members 17 and 23 are distributed around the circumference of the respective coupling members and the axis of symmetry 8 so that the coupling members 17 and 23 are supported in alignment with the axis of symmetry 8 and are not subject to cogging. Since the projections 16 and 22 extend relatively far into the grooves of the respective coupling members 17 and 23 preferably in the form of a fork, the engagement forces are advantageously distributed at opposite sides of the axis of symmetry 8 , thereby avoiding the transmission of moments to the needle and, respectively, the canula. Cogging of the coupling members 17 and 23 in the bore 21 is therefore very unlikely.
[0023] At the upper end of the housing, an actuating pin 28 is axially movably supported in an end bore 30 of the housing 1 for initiating the biopsy procedure. At its front end, the actuating pin 28 has a conical end surface 29 , which is disposed in the bore 21 for unlocking the elastic webs 19 from the shoulder 27 .
[0024] [0024]FIGS. 2 a to 2 c show the tensioning procedure of the biopsy device according to the first embodiment. FIG. 2 a shows the biopsy device in the rest position, in which both spring force storage structures are released, that is, the two pistons 4 and 5 are seated on the stops 10 and 11 engaging them with a force according to the pre-pressurized pressure medium 9 . (See also FIG. 1). In the following step as shown in FIG. 2 b , the piston 5 is pushed by hand via the cap 15 into the bore 3 of the housing 1 whereby the pressure medium 9 is further compressed. Concurrently, with the piston 5 , the coupling member 17 with the biopsy needle 18 is retracted until the locking hooks at the ends of the webs 19 engage the shoulder 27 . Subsequently, or at the same time, the canula 24 with the coupling member 23 and the piston 4 are retracted via the cap 14 against the pressure of the pressure medium 9 in the cylinder bore 2 until the locking hooks at the free ends of the webs 25 engage the shoulder 26 (FIG. 2 c ). Both spring force storage structures are now under tension. The biopsy device is now ready for use.
[0025] [0025]FIGS. 3 a to 3 c illustrate the insertion procedure for taking a tissue sample. The pistons 4 and 5 are at the beginning pressurized by the pressure medium 9 . The locking hooks of the webs 25 and 19 of the coupling members 17 and 23 hold the biopsy needle 18 and the canula 24 in the retracted position. Upon manual insertion of the actuating pin 28 into the housing 1 , the elastic webs 19 of the coupling member 17 are pushed together inwardly by the conical end surface 29 so that, finally, the locking hooks are pushed off the shoulder 27 and the coupling member is released. Driven by the pressure medium, the biopsy needle 18 then is rapidly propelled forwardly into a patients tissue of which a sample is to be taken until the piston abuts the stop 11 . Shortly before this instant the conical surface area 20 of the coupling member 17 engages the webs 25 , which are thereby pushed toward each other so that the locking hooks of the webs 25 are pushed off the shoulder 26 , whereby the coupling member 23 is released (FIG. 36) so that the pressurized piston 4 can impel the canula 21 over and toward the front of the biopsy needle 18 . The forward movement of the canula 24 is limited by the seating of the piston 4 on the stop 10 (FIG. 3 c ). Because of the high speed of the canula 24 , the tissue 32 present in the recess 31 of the biopsy needle 18 is cut off and the canula 24 encloses the tissue sample 33 . The biopsy device is now in its rest position and can be removed from the tissue for an examination of the tissue sample collected in the needle recess.
[0026] For the removal of the tissue sample 33 , the canula 24 is manually pulled back by pushing back the cap 14 , whereby the recess 31 is exposed and the tissue sample 33 can be removed from the recess of the needle.
[0027] The biopsy device of the second embodiment is shown in FIG. 4 in a rest position. It is different from the embodiment described above in that it is equipped, instead of a pressure medium 9 , with compression springs 34 and 35 , which act on the pistons 36 and 37 . The operation of the device shown in FIG. 4, particularly the charging and release procedure according to FIGS. 2 a to 2 c and 3 a to 3 c , are the same as described for the embodiment of FIG. 1.
[0028] [0028]FIG. 5 shows a biopsy device in a third embodiment in a rest position, that is with the springs relaxed. In contrast to the two embodiments described above, each of the spring storage devices includes at least one highly elastic rubber tension spring 38 each being pre-tensioned already in the rest position. The rubber springs 38 extend axially through bores in the pistons 4 and 5 and have at their opposite ends head portions by which they are supported, at one end in the housing 1 near the seals 10 and 11 and, at the opposite end, they are fixed to the pistons 4 and 5 . In this embodiment, the caps are not present by way of which the springs are tensioned like in the first two embodiments. Rather, the pistons 4 ′ and 5 ′ are each provided with operating handles 39 and 40 which extend from the housing 1 through guide slots 41 and 42 .
[0029] As spring force storage elements highly elastic bands, preferably rubber bands, are suitable which rubber bands are guided outside the housing and are attached thereto. They may act on carrier members, which transfer their movement to the biopsy needle and the canula within the housing. The carrier members may be guided together with a slide member parallel to the advance movement path of the biopsy needle and the canula. Like in the earlier described embodiments, the movement is transferred to the coupling members of the biopsy needle and the canula by projections, which extend into openings in the coupling members (see reference numerals 16 and 22 in the figures). Functionally, the slide members replace the pistons 4 and 5 of the embodiments described earlier. This particular variant is not shown in the drawings.
[0030] In all the embodiments described the biopsy needle 18 and the canula 24 form, together with the coupling members 17 and 23 , a separate design unit. This unit may be in the biopsy device a one-way unit, which is easily replaceable. If the replacement of this unit is required, the housing 1 of the biopsy device should be so designed that the central bore 21 is accessible for the replacement. Below, on the basis of FIGS. 6 and 7, two design concepts are presented. In these embodiments, rubber springs are shown but any of the spring arrangements referred to earlier may be used instead.
[0031] [0031]FIGS. 6 a to 6 c show an opening mechanism for the central bore 21 in top and side views, wherein the housing 1 includes the spring force storage devices 43 and is provided with a door 44 . The door 44 is supported so as to be pivotable about the center part of one of the two spring force storage structures 43 and are provided with a snap lock structures 43 and is provided with a swap lock 45 for locking engagement with the other spring force storage structure. FIGS. 6 a and 6 b show the biopsy device closed, FIGS. 6 c to 6 e show it with the door 44 open, whereby the central bore 21 is accessible from the side. As apparent from FIGS. 6 b and 6 c , it is not necessary to open the side of the housing 1 remote from the biopsy needle for the insertion of the replaceable unit described above.
[0032] In this way, this area of the housing is not weakened so that the opening mechanism as described may also be used for a biopsy device according to the first embodiment with pressure medium-based spring force storage structures as shown in FIGS. 1 to 3 , in which particularly this area of the housing 1 is stressed by the pressure of the pressure medium 9 .
[0033] As an alternative, also the second variant of the opening mechanism is suitable wherein, as shown in FIGS. 7 a to 7 d , the housing 1 is divided along the central bore 21 such that two housing halves each with one spring force storage element are formed. FIGS. 7 a and 7 b show such a biopsy device in a closed state, FIGS. 7 c and 7 d show it opened. As apparent from the sectional views 7 a and 7 c , the two housing halves are pivotally joined by a hinge 46 . When closed (FIG. 7 a ), a snap lock 45 of one housing half engages the other housing half. As a further variant, the hinge 46 may be replaced by a flexible element or by another snap lock.
[0034] It is pointed out that the biopsy needle and the canula and also the spring force storage structure should not comprise any magnetic or electrically conductive material. Rather, they may consist of plastic, which may be fiber reinforced or they may consist of a ceramic material.
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In an automatic biopsy device comprising a housing in which a biopsy needle is axially movably supported by a needle support structure and a canula extending around the needle is axially movably supported by a canula support structure, and first and second spring force storage structures are provided for biasing the biopsy needle and the canula, respectively, toward an extended position and the biopsy needle and canula support structures are held in a retracted position by respective first and second releasable locking means, releasing means are provided for manually releasing the first locking means to permit the needle to be propelled by the first spring force storage structure and to release the second locking structure by releasing means of the needle support structure to permit the canula to be propelled by the second spring force storage structure, the biopsy needle and canula and also the spring force storage structures consisting of a non-magnetizable electrically non-conductive material.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a tape winding apparatus for winding a certain length of tape, such as a magnetic tape, inside a cassette.
2. Description of the Prior Art
The tape winding apparatus is used for producing marketable cassettes in which video tapes, audio tapes and ribbon tapes are wound. This tape winding apparatus can be classified into two types: one that directly winds a tape, for example a magnetic tape, onto a hub which is stored in a cassette beforehand; and, one that winds the magnetic tape onto the hub before it is stored in the cassette.
The first type is disclosed in the Japanese Patent Laid-Open No. 4-47577. This conventional apparatus is comprised of: a tape supply means which continuously forwards the magnetic tape by holding and rotating a reel in which the length of magnetic tape is wound; a winding station which winds the forwarded magnetic tape on the hub inside the cassette; and, a cassette ejecting means which ejects the cassette when the magnetic tape in the cassette has been completely wound by the winding station.
In addition, the conventional apparatus includes a setting means which sets up the tape winding operation by inputting information, such as winding length, winding speed, winding tension and type of magnetic tape, so as to wind the magnetic tape on the hub inside the cassette. The information is manually input utilizing keyboards or switches.
Conventional tape winding apparatus have no problems as long as similar lengths of magnetic tape are wound on similar types of cassettes. However, when a variety of cassettes are produced in small amounts, a great deal of labor is required to meet the many different winding conditions. As a result, many errors are made in inputting the information during the setting means.
Another disadvantage associated with conventional tape winding apparatus is that, during production, the many different types of cassettes often get mixed together. Therefore, all products have to be inspected after production. In addition, if a long magnetic tape is accidentally wound on a small cassette, the cassette may get damaged and the tape winding apparatus will stop functioning.
OBJECT AND SUMMARY OF THE INVENTION
The object of the present invention is to solve the above-mentioned problems and provide a tape winding apparatus which does not require excessive labor in meeting various winding conditions and which inputs information without causing any errors. Another object is to provide a tape winding apparatus which can deal with a variety of cassettes.
In order to solve the above problems, the tape winding apparatus of the present invention, having a winding station for winding a desired length of the tape inside a cassette, is comprised of:
a detection means for detecting identification information for winding the tape which is accommodated in the cassette; and,
a control means for controlling the winding operation in the winding station based on the information received from the detection means.
The tape winding apparatus further includes a distribution means which distributes various types of cassettes. The control means commands the distribution means, based on the information from the detection means, to distribute cassettes so that tapes are wound by the winding station.
In another embodiment of the present invention, a tape winding apparatus for winding a tape of desired length inside a cassette is comprised of:
a winding station for winding tapes in the cassette;
a setting means for setting up winding conditions in said winding station by inputting information so as to wind the tape in the cassette;
a control means for controlling the winding operation of the winding station based on the setting conditions of said setting means;
a detection means for detecting identification information provided in the cassette which is regarded as the winding information of the tape; and,
a distribution means for distributing various types of cassettes.
The control means prevents the winding station from performing the winding operation and sends the cassette to the distribution means when the winding information, set by the setting means, and the identification information, detected by the detection means, do not match.
The detection means consists of a plurality of optical sensors which detect whether or not a plurality of holes are provided on the cassette surface. The plurality of holes serve as the identification information.
In addition, the detection means is comprised of a bar code reader which detects the bar code provided on the cassette surface. The bar code also serves as part of the identification information.
Furthermore, the detection means is comprised of a reading apparatus which reads out the stored information provided on the cassette surface. The stored information is also part of the identification information.
The tape winding apparatus of the present invention has several advantages. One advantage is that the winding conditions can be easily altered, thereby preventing a decrease of production efficiency caused by input errors. Another advantage is that present invention can simultaneously convey and distribute a variety of cassettes produced in small amounts.
In addition, even if different types of cassettes are accidentally mixed together, it is possible for the present invention to eliminate the wrong cassettes by detecting the identification information and distributing the cassettes. Therefore, an accident which would typically halt the production line is prevented. Finally, due to the detection means, there is no need to count the total number of completed cassettes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the preferred embodiment of the tape winding apparatus of the present invention.
FIG. 1A is a cross sectional view of a shift block of the tape winding apparatus of the present invention.
FIG. 2 is a schematic view of a cassette holder, a winding mechanism, a detection means and a distributing means, as viewed from a base panel side.
FIG. 3 is a block diagram showing the tape winding mechanism of the present invention.
FIG. 4 is a view showing a basic structure of the cassette.
FIG. 5 is a view showing and example of cassette having a bar code on its surface.
FIG. 6 is a view showing an example of cassette having a magnetic signal on its surface.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiment of the tape winding apparatus of the present invention is described as follows. FIG. 4 shows the basic structure of a cassette C before the magnetic tape is wound by the tape winding apparatus.
The cassette C, shown in FIG. 4, is an audio tape cassette comprised of: a case C1, a pair of hubs H stored in the case C1, and a leader tape L connected to the pair of hubs H. Winding shafts, engaged in the pair of hubs H, and a magnetic head are located at the site of the windows C2, C3 and C4, which are provided in the case C1. As a result, the leader tape L and magnetic tape M are wound from outside. Further, three holes D1, D2 and D3 are provided on a surface C5 of the case C1 as identification information. Combinations of these holes D1, D2 and D3 indicate the length of magnetic tape M stored therein. For example, the holes arranged in an order of D1, D2 and D3 indicates a sequence of "short", "medium" and "long".
FIG. 2 shows a schematic view of a cassette holder 12, a winding mechanism 16, a detection means 6 and a distribution means 5, as viewed from a base panel side.
The tape winding apparatus of the present invention, as shown in FIG. 1, includes a winding station 1 which winds the magnetic tape M within the cassette C. The winding station 1 is comprised of: a reel plate 10, a shift block 11, the cassette holder 12, a leader tape pullout mechanism 13, a cutter mechanism 14, a splicing mechanism 15 and a winding mechanism 16. These components enable the winding station 1 to pull out and cut the leader tape L, which is connected beforehand to the pair of hubs H. The cut end of the leader tape L is connected to the end of the magnetic tape M so that, when the hubs H are rotated, the magnetic tape M is wound.
The reel plate 10 is comprised of a removable clamper 17 and a motor (not shown), which continuously forwards the magnetic tape M. The removable clamper 17 holds a reel R onto which the length of magnetic tape M is wound.
The shift block 11 includes two blocks 18 and 19, as shown in FIG. 1A. The block 18, shown in the right-hand side in the drawing, includes two grooves 18A and 18B, whose widths are equivalent to that of the magnetic tape M. The other block 19 includes a groove 19A whose width is equivalent to the width of grooves 18A and 18B. Each groove is parallel to the base panel B. Furthermore, when the right block 18 shifts to either the right or left direction against the base panel B, the groove 19A of the other block 19 is aligned with either of the grooves 18A or 18B. These grooves include a plurality of holes 11A, whereby the magnetic tape M and the leader tape L can be held by air suction.
As shown in FIG. 2, the cassette holder 12 holds the cassette C by surrounding the cassette with side plates 20 and 21 and supporting the bottom of the cassette with a projectable pair of pins 22. When these pins 22 are pulled in, the cassette C is ejected and falls down.
Referring to FIG. 1, the cassette supply mechanism 23, located above the cassette. holder 12, is comprised of two rails 24 and 25. A plurality of cassettes C may be held between these rails 24 and 25. The cassettes are sequentially conveyed to the cassette holder 12 by a free fall effect.
The leader tape pullout mechanism 13 is comprised of a suction mechanism 26 and a placement mechanism 27. The suction mechanism 26 partially pulls out the leader tape L from the cassette C by utilizing a suction feature. The placement mechanism 27 places the leader tape L on the shift block 11 by inserting a pullout pin (not shown) into a hole of the leader tape and pulling the leader tape.
The cutting mechanism 14 is comprised of a blade 14A and a reciprocating drive source (not shown), which reciprocates on the blade 14A. The cutting mechanism 14 cuts the magnetic tape M or the leader tape L, which is held on the shift block 11 by suction means.
The splicing mechanism 15 attaches the magnetic tape M to the leader tape L. The splicing mechanism cuts the splicing tape S, which is wound on a reel 28, to a predetermined length and moves it to the shift block 11. The splicing mechanism then attaches the splicing tape S, thereby coupling the magnetic tape M to the leader tape L.
As shown in FIG. 2, the winding mechanism 16 is comprised of: a winding shaft 29, whose end is adapted to engage with the hub H; a moving mechanism (not shown) for moving the winding shaft 29, so as to engage it with one of the hubs H of the cassette C which is held in the cassette holder 12; and, a motor (not shown) for rotating the winding shaft 29, whereby the hub H is rotated and the magnetic tape M is wound.
Next, the operation of the winding station 1 of the preferred embodiment of the present invention will be described, with reference to FIGS. 1 and 1A.
First, the magnetic tape M is pulled out from the reel plate 10. The end of the magnetic tape is held by suction in one of the grooves of the right block 18 of the shift block 11. Next, the leader tape L is partially pulled out from the cassette C, which is located at the bottom of the cassette supply mechanism 23, by means of the suction mechanism 26. Then, the cassette C falls or drops from the cassette supply mechanism 23 into the cassette holder 12. The leader tape pullout mechanism 13 then pulls the leader tape L from the cassette C and places it on the shift block 11.
With the leader tape L on the shift block 11, the cutting mechanism 14 cuts the leader tape L. The shift block 11 then shifts the right block 18 so that the cut end of the leader tape L contacts an end of the magnetic tape M. The splicing mechanism 15 connects the attached magnetic tape M and the leader tape L. At this point, the shift block 11 releases the suction on the attached tapes M and L. Finally, the winding mechanism 16 winds the magnetic tape M by rotating one of the hubs H of the cassette C.
After winding a certain length of the magnetic tape M, the winding mechanism 16 stops the rotation of the hub H. Once again, the shift block 11 holds the magnetic tape M by suction and the cutting mechanism 14 cuts the magnetic tape M. The shift block 11 then shifts the right block 18 so that the cut end of the leader tape L, which is suction-held by the other block 19, contacts the cut end of the magnetic tape M, which is wound in the cassette C. Next, the splicing mechanism 15 attaches the magnetic tape M to the leader tape L.
At this point, the shift block 11 releases the suction on the attached magnetic tape M and leader tape L. Once again, the winding mechanism 16 rotates the hub H so as to rewind the magnetic tape M and the leader tape L onto the cassette C. Finally, the completed cassette is ejected from the cassette holder 12. By repeating the previously described operation, cassettes may be continuously produced.
The following describes operations of the other mechanisms. As shown in FIG. 2, the distribution means 5 is comprised of a chute plate 50 and a sloped plate 51. Two conditions, a projecting (an interfering) condition and a non-projecting (non-interfering) condition, can occur at the distribution means 5. When the sloped plate 51 does not project across the chute plate 50, the cassettes C, ejected from the cassette holder 12, fall smoothly through the chute plate 50 without experience any interference. The cassettes C are then ejected to the outside conveyer. When the sloped plate 51 does project across the chute plate 50, the cassettes C, ejected from the cassette holder 12, fall onto the sloped plate 51 and are ejected in a different direction. The ejected cassettes C are then stored in a different place.
As shown in FIG. 2, the detection means 6 is comprised of three optical sensors 60, 61 and 62. The sensors detect the existence of holes D1, D2 and D3 in the cassette C held in the cassette holder 12. Combinations of the holes D1, D2 and D3 indicate various winding information, such as the length of magnetic tape M written in the cassette C.
The setting means 7, shown in FIG. 1, consists of a plurality of switches and a keyboard and is operated from outside. The winding information, such as the length of the magnetic tape M, a winding speed or a tension for winding the tape in the cassette C, is input therein.
The control means 8 is comprised of a micro processor. As shown in FIG. 3, the control means 8 controls the operations of the winding station 1 and the distribution means 5 based upon the information received from the detection means 6 and the setting means 7. The control means 8 instructs the winding station 1 to begin the winding operation, based upon the information received from the detection means 6. In addition, the control means 8 instructs the distribution means 5 to distribute different types of cassettes based upon the information received from the detection means 6. Alternatively, the control means 8 compares the information received from the setting means 7 and the detection means 6. If they do not match, the control means 8 discontinues the winding operation and instructs distribution means 5 to eject the cassette C therefrom.
The above-described winding apparatus can perform the following two operations. In the first operation, the detection means 6 detects whether or not there are holes D1, D2 and D3 on the cassette C. Based upon this information, the control means 8 determines the length of magnetic tape M to be wound in the cassette C by the winding station 1. Then, that length of magnetic tape M is wound in the cassette C.
This operation allows the magnetic tape M, being of varying lengths, to be wound in a variety of cassettes C without setting winding conditions. Thus, the separation of completed cassettes C, based upon the lengths of the magnetic tape M, is not necessarily needed for this operation.
In the second operation, the setting means 7 sets up winding conditions, such as the winding lengths, of the winding station 1. Next, the detection mean 6 detects whether or not there are three holes D1, D2 and D3 provided on the cassette C. The control means 8 compares the winding length information set by the setting means 7 and the winding length information detected by the detection means 6. If the information does match, the winding operation proceeds so as to complete genuine cassette products. However, if the information does not match, the cassette C is considered to be defective and is led to the distribution means 5; then, it is ejected therefrom. Therefore, this operation prevents different types of cassettes being mixed together.
In addition, the detection means can be formed of a bar code reader which detects a bar code provided on the cassette surface, Futhermore, the detection means can be comprised of a reading apparatus which reads the stored information provided on the surface of the cassette surface such as a magnetic means. FIGS. 5 and 6 show each examples of cassette having a bar code and a means for storing a magnetic signal, respectively, indicating the identification information on their surfaces.
Obviously, numerous variations and modifications can be made without departing from the spirit of the present invention. Therefore, it should be clearly understood that the forms of the present invention described above and shown in the figures of the accompanying drawings are illustrative only and are not intended to limit the scope of the present invention.
In another embodiment of the present invention, the detection means is defined as a means for detecting the identification information which indicates length of magnetic tape M (depending upon the arrangement of the holes D1, D2 and D3). However, other information, such as winding speeds and tension of the magnetic tape, can also be included in the identification information.
In the preferred embodiment, a plurality of holes was provided on the cassette surface as the identification information of the cassette C. However, as an alternate embodiment, memory information or the like is provided on the cassette C. The information is stored in the form of bar codes or electro-magnetic induction. For this embodiment, the detection means 6 is a reading apparatus used for detecting the information.
In the preferred embodiment, the detection means 6 was accommodated in the cassette holder 12 so as to detect the identification information of the cassettes C. The distribution of cassettes C was performed at the lower side of the cassette holder 12. In yet another embodiment, it is also possible to provide the detection means 6 and the distribution means 5 under the cassette supply means 23 so that they detect the identification information of the cassettes C and distribute them therefrom. In this case, if a cassette is found to be defective, that cassette C can be pushed in either the right or left direction and removed from the cassette supply means 23. With this method, the detection and distribution of cassettes C can be performed while the magnetic tape M is being wound in the cassette. Therefore, production efficiency is improved.
In the preferred embodiment, the distribution means 5 was adapted to distribute the cassettes using the chute plate 50 and the sloped plate 51. In another embodiment, however, the chute plate 50 is arranged to be able to distribute cassettes in several directions, such as right, left, front or back. Thus, a wider variety of cassettes can be separated and distributed thereby.
In the preferred embodiment, the cassettes C are defined as audio tapes. However, other types of tapes, such as video tapes, ribbon tapes or the like, may also be used.
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A tape winding apparatus, for winding a certain length of magnetic tape in a cassette, comprises a detection unit and a cassette distributor. The detection unit detects the existence of holes on the cassette, which are regarded as information used in winding the magnetic tape. The winding operation of the winding station is controlled by the information received from the detection unit. If the information set by a controller and the information detected by the detection unit do not match, the cassette is regarded as defective and is distributed to the appropriate location by the cassette distributor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. Non-Provisional application Ser. No. 14/386,165, which was filed on Sep. 18, 2014. application Ser. No. 14/386,165 is a National Stage of PCT/EP2013/053795, which was filed on Feb. 26, 2013. This application is based upon and claims the benefit of priority to European Application No. 12160257.7, which was filed on Mar. 20, 2012.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a process for the preparation of D,L-methionine with a high bulk density, where the methionine is purified by recrystallization.
[0003] L-Methionine is an essential amino acid which is of great industrial importance as a feed supplement. Since D- and L-methionine are of identical nutritional value, the racemate is usually used as feed supplement. The synthesis of D,L-methionine proceeds starting from methylmercaptopropionaldehyde and hydrogen cyanide with the preparation of the intermediate 5-(2-methylmercaptoethyl)hydantoin, which can be converted to the methioninate by hydrolysis.
[0004] Various processes are known both for the hydrolysis of hydantoin and also for the subsequent release of methionine from its salt. The present invention relates to the preparation of methionine by the so-called potassium carbonate process, which is described for example in EP 1 256 571 A1 and DE 19 06 405 A1. In this connection, 5-(2-methylmercaptoethyl)hydantoin in aqueous solution is firstly reacted with potassium carbonate to give potassium methioninate with the release of carbon dioxide and ammonia. By introducing carbon dioxide, the basic potassium methioninate solution is neutralized and methionine is precipitated out. The crude methionine obtained in this way, however, is produced in the form of platelet-like or flake-like, poorly filterable crystals, which are shown in FIG. 1 .
[0005] To control the foaming and to improve the crystal quality, the crude methionine precipitation according to EP 1 256 571 A1 takes place in the presence of an antifoam. This process has the disadvantage that methionine is obtained in the form of spherical, but porous particles, which are shown in FIG. 2 . Because of its porous structure, the methionine obtained in such a way has to be washed with large amounts of water and dried, incurring high energy costs, in order to arrive at a marketable product.
[0006] The addition of additives during the crude methionine precipitation can improve the crystal quality. As additives, for example sorbitan laurate, polyvinyl alcohol, hydroxypropylmethylcellulose, gluten or casein are known from JP 11158140 and JP 10306071. According to these processes, methionine crystals with a bulk density of up to 770 g/l are obtained. It has proven to be disadvantageous for these processes that they are carried out as batch processes or in merely semicontinuous mode.
[0007] It is likewise known to improve purity and bulk density of methionine by recrystallization of crude methionine. JP 2004-292324 discloses, for example, the recrystallization of crude methionine by adding polyvinyl alcohol or gluten, giving pure methionine with a bulk density of up to 580 g/l. The recrystallization takes place by the dropwise addition of a hot methionine solution to a cold methionine suspension, with methionine precipitating out as a result of cooling the hot solution. A disadvantage has again proven to be that this process is not carried out continuously.
[0008] EP 1 451 139 A1 describes the recrystallization of methionine in the presence of hydroxyethylcellulose, with initially methionine crystals having a bulk density of up to 620 g/l being obtained. In this case, a disadvantage has proven to be that in a continuous recrystallization process there is an accumulation of the continuously added additive as a result of reusing the filtrate for dissolving crude methionine and that an increasing additive concentration results in a reduction in the bulk density. For this reason, hydroxyethylcellulose is not advantageous for use as crystallization additive in a continuous process in which the filtrate of the pure methionine is reused for dissolving crude methionine. The reuse of the recrystallization filtrate is of decisive importance for the economic feasibility of the process on an industrial scale since losses of dissolved methionine are avoided and the generation of wastewater is minimized.
[0009] JP 46 019610 B1 describes a process for the recrystallization of methionine, which however does not allow to achieve high bulk densities for methionine.
[0010] It is an object of the present invention to provide a process for the preparation of methionine which avoids the described disadvantages. The methionine obtained by the process should be readily filterable and have a high bulk density. Furthermore, the process should be able to be carried out in continuous mode and in particular should avoid the negative consequences of accumulation processes.
BRIEF SUMMARY OF THE INVENTION
[0011] To achieve this object, the present invention provides a process for the preparation of D,L-methionine, in which carbon dioxide is fed to an aqueous potassium methioninate solution obtained by hydrolysis of 5-(2-methylmercaptoethyl)hydantoin, in order to precipitate out crude methionine, which is separated off and purified, where, for the purposes of purification, an aqueous solution of the separated-off crude methionine is prepared and subjected to a recrystallization. In the process, the solution from which the recrystallization takes place contains potassium ions and also a crystallization additive, where the crystallization additive is a nonionic or anionic surfactant, or a mixture of different nonionic or anionic surfactants. According to the invention, the recrystallization takes place by introducing a 60 to 110° C.-hot methionine solution into a 35 to 80° C.-warm methionine suspension, the temperature of which is lower than that of the introduced solution, the temperature of the methionine suspension being maintained between 35 and 80° C. during the addition.
[0012] The hot methionine solution is preferably cooled rapidly by introducing it into the initial charge of cooler methionine suspension, as a result of which a superconcentration of dissolved methionine is produced and methionine precipitates out from the solution. In this way, the preference in the crystal growth spatial direction is interrupted and an isometric crystal habit is achieved. However, besides the desired isometric crystals, it is also possible for undesired new, platelet-like crystal germs to form as a result of this rapid cooling mode. In one preferred embodiment of the process according to the invention, these can be specifically redissolved by moderately increasing the temperature by 5-15° C., preferably by 6-12° C., compared to the mixing temperature.
[0013] As a result of the combination according to the invention of the presence of potassium ions, the addition of crystallization additive and the temperature control of the recrystallization, coarsely granular, readily filterable methionine crystals with a bulk density of above 500 g/l are obtained.
BRIEF DESCRIPTION OF THE FIGURES
[0014] FIG. 1 illustrates a crude methionine produced in the form of platelet-like or flake-like, poorly filterable crystals;
[0015] FIG. 2 illustrates a crude methionine produced in the form of spherical, but porous particles;
[0016] FIG. 3 illustrates methionine obtained without the addition of crystallization additives, without the presence of potassium by simple cooling;
[0017] FIG. 4 illustrates a pure methionine according to one embodiment of the present disclosure;
[0018] FIG. 5 illustrates an arrangement, in diagrammatic form, for carrying out a process according to one embodiment of the present disclosure;
[0019] FIG. 6 shows a graph of the temperature-dependent solubility behaviour of methionine.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In a preferred embodiment of the process, the crystallization additive is one of the compounds shown in formulae 1 to 3, or a mixture thereof:
[0000] R 1 —O—SO 3 M (formula 1)
[0000] R 2 —O—(CH 2 ) n —SO 3 M (formula 2)
[0000] R 3 —(O—C 2 H 4 ) n —O—SO 3 M (formula 3)
[0021] where n is an integer from 1 to 12, M is sodium or potassium and R 1 , R 2 and R 3 are a linear, branched or cyclic, saturated or unsaturated C 8 to C 20 alkyl group or an aryl group.
[0022] In a preferred embodiment of the aforementioned compounds, n=2 and R 1 , R 2 and R 3 are linear, saturated C 8 to C 18 alkyl groups.
[0023] In a further embodiment of the process, the crystallization additive is a sorbitan fatty acid ester or a mixture of different sorbitan fatty acid esters, preferably polyethoxylated sorbitan fatty acid esters. In a particularly preferred embodiment, the crystallization additive is a polyethoxylated sorbitan stearate, and in particular a polyethoxylated sorbitan tristearate according to formula 4:
[0000]
[0024] where w+x+y+z=20.
[0025] The concentration of the crystallization additive in the solution from which the recrystallization takes place is preferably at least 50 ppm based on the total mass of the solution, particularly preferably at least 100 ppm, most preferably at least 400 ppm. In order to achieve an optimum dosing and distribution of the crystallization additive, it is preferably used in the form of an aqueous solution or emulsion, in which case the concentration of the crystallization additive in the solution or emulsion is preferably 2 to 15% by weight.
[0026] In a preferred embodiment of the process according to the invention, the solution from which the recrystallization takes place additionally comprises an antifoam. The antifoam has the function of suppressing the foam which is formed when handling the methionine solution and suspension and which is intensified and/or caused by some of the aforementioned crystallization additives. Moreover, a synergistic effect arises for the attained bulk densities of methionine when simultaneously using antifoam and crystallization additives, as a result of which bulk densities of more than 600 g/l are achieved, the negative consequences of accumulation processes are simultaneously avoided and the process according to the invention can thus also be carried out in continuous mode.
[0027] The antifoam preferably comprises silicone oil, preference being given to using a silicone oil with a kinematic viscosity of 0.65 to 10 000 mm 2 /s (measured at 25° C. in accordance with DIN 53018), particularly preferably from 90 to 1500 mm 2 /s. The antifoam can further contain constituents which are effective as emulsifiers, for example mixtures of polyethoxylated fatty acids and polyethoxylated fatty alcohols. The antifoam can likewise comprise silica. In a preferred embodiment, the antifoam is an aqueous solution which comprises 5 to 10% by weight of silicone oil, 0.05 to 1% by weight of silica, 0.5 to 5% by weight of a mixture of polyethoxylated fatty acids, and 2 to 7% by weight of a mixture of polyethoxylated fatty alcohols. Preferably, the antifoam is used in a mixture with the crystallization additive, the crystallization additive being admixed in a concentration of preferably 2 to 15% by weight. In order to achieve a continuous, stable dosing of the antifoam, it is preferably further diluted with water prior to being used.
[0028] The use of silicone oil antifoams leads to silicon being able to be detected in the methionine prepared by the process according to the invention using a suitable analysis method (e.g. X-ray photoelectron spectroscopy, abbreviated to XPS). Therefore, a further object of the present invention is D,L-methionine obtained by the process according to the present invention, wherein a silicone oil antifoam is used in said process.
[0029] Surprisingly, it has been found that the presence of potassium ions in the solution from which the recrystallization takes place is important for the crystallization success. Preferably, the potassium ion concentration in the solution from which the recrystallization takes place is 1 to 30 g/kg, particularly preferably 2 to 14 g/kg, most preferably 5 to 10 g/kg. The potassium preferably passes into the recrystallization solution with the crude methionine. The potassium concentration can be adjusted for example by introducing washing water during the crude methionine filtration and/or by introducing freshwater to the pure filtrate used for dissolving the crude methionine and/or by introducing potassium into the pure filtrate used for dissolving the crude methionine.
[0030] According to the invention, the crude methionine is dissolved in an aqueous solution before the recrystallization. This is effected preferably by heating the solution to a temperature of at least 95° C., particularly preferably by heating to boiling temperature. To dissolve the crude methionine, it is possible to use, for example, freshwater, the filtrate of the pure methionine, or the condensate of the vacuum crystallization described below or mixtures thereof.
[0031] According to the invention, crystallization additive and the antifoam are added to the aqueous matrix used for dissolving the crude methionine. In one possible embodiment of the process, the crystallization additive and the antifoam are also added to the solution from which the crude methionine is precipitated out.
[0032] Preferably, the recrystallization takes place by introducing an 85 to 110° C.-hot crude methionine solution into a 35 to 60° C.-warm methionine suspension, the temperature of the mixture that is formed as a result being kept constant between 35 and 60° C. In this connection, the volume ratio of the introduced crude methionine solution to the initial charge of methionine suspension is preferably in the range from 1:1 to 1:10, particularly preferably from 1:3 to 1:6.
[0033] In a further preferred embodiment of the process, the recrystallization is carried out in two stages. For this, in the first recrystallization stage, an 85 to 110° C.-hot crude methionine solution is introduced into a 60 to 80° C.-warm methionine suspension and the temperature of the mixture that is formed as a result is kept constant between 60 and 80° C. It is particularly preferred here to remove some of the methionine suspension from the first recrystallization stage and to return it again to the recrystallization via a circulation circuit, the temperature of the suspension in the circulation circuit being increased by 6 to 12° C. The 60 to 80° C.-warm methionine suspension obtained in the first recrystallization stage is introduced, in a second recrystallization stage, into a 35 to 60° C.-warm methionine suspension, the temperature of the mixture that is formed as a result being kept constant between 35 and 60° C. The volume ratio of the introduced methionine suspension to the initial charge of methionine suspension is preferably in the range from 1:1 to 1:10, particularly preferably from 1:3 to 1:6.
[0034] Besides a first or a first and second recrystallization stage, the process according to the invention can also involve further recrystallization stages.
[0035] In the event of a multistage procedure, all stages can be charged in parallel with crude methionine at the same temperature difference between crude methionine solution and initial charge of methionine suspension. The multistage recrystallization can also be carried out such that the recrystallization stages are successively charged with the methionine solution from the proceeding stage, the temperature difference between crude methionine and methionine solution being selected such that the methionine solution from one recrystallization stage can be used as crude methionine for the next recrystallization stage. This has the advantage of reduced formation of undesired platelet-like crystals as a result of excessively large temperature differences. The multistage recrystallization of course also involves mixed forms of parallel and consecutive charging of the recrystallization units.
[0036] The preferred temperature control for the process according to the invention arises from the temperature-dependent solubility behaviour of methionine shown in FIG. 6 .
[0037] In economic terms, it is expedient to cool the methionine solutions to an end temperature of from 30 to 50° C. since, in so doing, both the amount of methionine remaining in solution can be minimized, and also the use of expensive cooling media for the purposes of further cooling the methionine-containing solutions is avoided.
[0038] In a preferred embodiment of the process, the recrystallization is carried out by vacuum crystallization. Here, the pressure in the first recrystallization stage is preferably 100 to 1000 mbar, particularly preferably 150 to 400 mbar. If a two-stage recrystallization is carried out, the pressure in the second recrystallization stage is preferably 35 to 200 mbar, particularly preferably 35 to 100 mbar. Preferably, the water evaporated in the vacuum crystallization is condensed and is reused for dissolving further crude methionine.
[0039] In one preferred embodiment of the process, some of the methionine suspension is removed from the first and/or one of the other recrystallization stages and is returned again via a circulation circuit. In the first crystallization stage, the hot methionine solution is preferably added to the circulated colder suspension in a volume ratio of 1:3 to 1:6. Upon this rapid cooling, a high supersaturation is produced, as a result of which, on the one hand, relatively large crystals grow isometrically, or else new, small, platelet-like crystals are formed. The small platelet-like crystals are also dissolved again in the recirculation line by increasing the temperature by 6 to 12° C., the isometric relatively large crystals being retained.
[0040] Separating off the pure methionine from the mother liquor of the recrystallization preferably takes place by filtration, for example pressure or vacuum filtration, or by means of centrifuges, for example trailing-blade, pusher-type or screen centrifuges.
[0041] The process according to the invention can either be carried out continuously or else discontinuously or semicontinuously.
[0042] The attached FIGS. 1 to 4 show electron micrographs of crystalline methionine. FIG. 1 shows crude methionine as is obtained from the crude methionine precipitation without the addition of crystallization additives. FIG. 2 shows crude methionine from the crude methionine precipitation with the addition of an antifoam according to EP 1 256 571 A1. FIG. 3 shows methionine as is obtained without the addition of crystallization additives, without the presence of potassium by simple cooling. FIG. 4 shows pure methionine as is obtained with the process according to the invention.
[0043] FIG. 5 shows, by way of example and in diagrammatic form, an arrangement for carrying out the process according to the invention in a preferred two-stage recrystallization. In container A, crude methionine is dissolved with an aqueous matrix, which can comprise the filtrate of the pure methionine, at a temperature of from 90 to 100° C. The temperature is adjusted via a circulation pump and an external heat exchanger. The crystallization additive according to the invention including antifoam is added continuously to the aqueous matrix. The methionine solution is heated to 100 to 110° C. via one or more heat exchangers B and then fed to the circulation circuit of the first vacuum crystallizer D. The circulated suspension has a temperature of 60 to 70° C. The ratio of amount fed in to circulation amount is in the range from 1:3 to 1:6. The average residence time of the mixture in the circulation circuit is 5 to 15 sec. The mixture is heated to 65 to 75° C. via a heat exchanger C, as a result of which fine and in particular platelet-like methionine crystals rapidly dissolve because of their relatively large specific surface area. The mixture then passes to the first vacuum crystallizer D, in the top region of which, at a pressure of 180 to 200 mbar, water evaporation and cooling of the mixture occurs. This results in crystallization of dissolved methionine. The methionine crystals settle out in the vacuum crystallizer at differing rates. Small, platelet-like crystals settle out more slowly than coarse, isometric crystals. The suspension for recirculation is removed in the upper region of the vacuum crystallizer, where predominantly smaller, platelet-like crystals are found on account of the slower settling rate. The coarse, isometric crystals are removed in the lower region of the vacuum crystallizer D and fed to the circulation circuit of the second vacuum crystallizer E. The suspension circulated here has a temperature of 30 to 50° C. The ratio of amount fed in to circulation amount is in the range from 1:3 to 1:6. The pressure in the vacuum crystallizer E is 60 to 80 mbar. In vacuum crystallizer E, further methionine is crystallized, as a result of which the average particle size of the methionine crystals in particular is increased. If required, the methionine suspension can be passed to an interim container F in order to permit a postprecipitation of methionine. Finally, the methionine is isolated in a suitable solid/liquid separation step G, where the filtrate obtained can, if required, be returned to container A.
[0044] The examples below aim to explain the invention in more detail.
EXAMPLES
Example 1
Recrystallization in the Presence of a Crystallization Additive According to the Invention Compared with a Known Crystallization Additive
[0045] 60 g of methionine, 305 g of water and 35 g of crude methionine filtrate were introduced into a flask and circulated via a heat exchanger by pumping at a temperature of 40° C. As a result of the potassium carbonate present in the crude methionine filtrate, the potassium ion concentration was ca. 7 g/kg. A solution, heated to 90° C., of 150 g of methionine in 990.5 ml of water and 109.5 g of crude methionine filtrate was added to this suspension at a rate of 18 ml/min, during which the temperature of the initial charge of suspension was kept at 40° C. After adding 650 ml of the hot solution, 500 ml of suspension were removed and then a further 500 ml of the hot solution were metered in at a rate of 18 ml/min. The resulting suspension was discharged, the amount of foam was determined, and the methionine was filtered off and washed with 300 ml of acetone. After drying the methionine, the bulk density was determined.
[0046] The recrystallization experiments were carried out in the presence of the following additives, the stated concentration being established by adding the additive to both starting solutions/suspensions. The concentration data give the total active ingredient content of the additive without water based on the total mass of the solution or suspension. Additive 1 was an aqueous mixture of antifoam and crystallization additive according to EP 1 451 139 A1, consisting of 2% by weight of hydroxyethylcellulose and 2% by weight of a polyethoxylated fatty acid (C 18 H 37 —(CO)—O—(CH 2 —CH 2 O) 7 —H). Additive 2 was an aqueous mixture of a crystallization additive and an antifoam composition according to the present invention, consisting of 6.1% by weight of silicone oil with a kinematic viscosity of 1000 mm 2 /s (AK 1000, Wacker-Chemie GmbH), 0.25% by weight of hydrophobicized silica (Sipernat D10, Evonik Degussa GmbH), 2.6% by weight of a polyethoxylated fatty acid mixture (Intrasol® FS 18/90/7, Ashland Deutschland GmbH), 3.7% by weight of a polyethoxylated fatty alcohol mixture (2.35% by weight of Marlipal®, Sasol Germany GmbH, 1.35% by weight of Brij C2, Croda Chemicals Europe) and 5.1% by weight of a fatty alcohol sulphate (Sulfopon® 1218 G, Oleochemicals) according to the formula:
[0000] C n H 2n+1 —O—SO 3 Na,
[0047] where n=12 to 18.
[0048] The table below shows the ascertained amounts of foam and methionine bulk densities as a function of type and concentration of the mixtures used as crystallization additives, the total active ingredient content (without water) being given.
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
None
—
300
507
1
200
180
614
1
400
75
626
1
1000
10
587
1
1200
10
464
1
2000
10
410
1
4000
5
356
2
200
40
613
2
400
5
633
2
1000
0
610
2
1200
0
651
2
2000
0
625
2
4000
0
639
[0049] It is observed that the crystallization additive according to the invention at a low concentration improves the bulk density as effectively as the additive according to EP 1 451 139 A1 and that the additive according to the invention, in contrast to the additive according to EP 1 451 139 A1, retains its effectiveness even at a high concentration.
Example 2
Recrystallization in the Presence of Pure Antifoam, Pure Crystallization Additives, and Mixtures of Antifoam and Crystallization Additive
[0050] Recrystallization experiments according to the procedure from Example 1 were carried out with the addition of pure crystallization additives according to the invention, of mixtures of the crystallization additives with the antifoam and of the pure antifoam. The table below shows the amounts of foam and methionine bulk densities ascertained here.
[0051] The pure antifoam (Comparative Example 1) was used in the form of an aqueous mixture consisting of 6.1% by weight of silicone oil with a kinematic viscosity of 1000 mm 2 /s (AK 1000, Wacker-Chemie GmbH), 0.25% by weight of hydrophobicized silica (Sipernat D10, Evonik Degussa GmbH), 2.6% by weight of a polyethoxylated fatty acid mixture (Intrasol® FS 18/90/7, Ashland Deutschland GmbH), 3.7% by weight of a polyethoxylated fatty alcohol mixture (2.35% by weight of Marlipal®, Sasol Germany GmbH, 1.35% by weight of Brij C2, Croda Chemicals Europe).
[0052] The pure crystallization additives used were the following anionic surfactants:
[0053] 2) C n H 2n+1 —O—SO 3 Na, where n=12 to 18 (Sulfopon® 1218G, Oleochemicals)
[0054] 3) C n H 2n+1 —O—C 2 H 4 —SO 3 Na, where n=8 to 18 (Hostapon® SCI 85, Clariant)
[0055] 4) C n H 2n+1 —(OC 2 H 4 ) 2 —O—SO 3 Na, where n=12 (Disponil® FES 27, Cognis)
[0056] 5) C n H 2n+1 —(OC 2 H 4 ) 12 —O—SO 3 Na, where n=12 (Disponil® FES 993, Cognis)
[0057] Comparative Example 6) C n H 2n+1 —(OC 2 H 4 ) 30 —O—SO 3 Na, where n=12 (Disponil® FES 77, Cognis)
[0058] For the mixtures of the antifoam with the crystallization additives, in each case 5.1% by weight of the corresponding crystallization additive was added to the aforementioned mixture and the water fraction was reduced by 5.1% by weight of:
[0059] 7) (1)+(2)
[0060] 8) (1)+(3)
[0061] 9) (1)+(4)
[0062] 10) (1)+(5)
[0063] Comparative Example 11) (1)+(6)
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
Comparative
400
70
474
Example 1
2
400
30-40
537
3
400
160
564
4
400
>300
560
5
400
>300
558
Comparative
400
>400
528
Example 6
7
400
5
633
8
400
5
624
9
400
20-30
613
10
400
40
581
Comparative
400
60
548
Example 11
[0064] The results show that the pure antifoam does not result in an improvement in bulk density (entry 1). The crystallization additives 2 to 5 according to the invention improve the bulk density to values >500 g/l, but in the majority of cases bring about increased foaming. The combinations 7 to 9 according to the invention of antifoam and crystallization additives lead to bulk densities >600 g/l, the combination 10 according to the invention leads to bulk densities >500 g/l, without increased foaming arising.
Example 3
Recrystallization in the Presence of Antifoam and Crystallization Additives or Antifoam and Mixtures of Crystallization additives
[0065] Further recrystallization experiments according to the procedure from Example 1 were carried out with mixtures of a antifoam and a crystallization additive or mixtures of an antifoam and several crystallization additives. For this purpose, the following mixtures were used:
[0066] 8) (1)+(3) in concentrations of 200, 400, 1200, 2000 and 4000 ppm
[0067] 9) (1)+(4) in concentrations of 200, 400, 1000, 1200, 2000 and 4000 ppm
[0068] 10) (1)+(5) in concentrations of 200, 400, 1000, 1200, 2000 and 4000 ppm
[0069] 11) (1)+((3)+(2) at the ratio of 1:1) in concentrations of 200, 400, 1200, 2000 and 4000 ppm
[0070] 12) (1)+((4)+(2) at the ratio of 1:2) in concentrations of 200, 400, 1200, 2000 and 4000 ppm
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
8
200
70
599
8
400
0
624
8
1200
0
616
8
2000
0
610
8
4000
0
610
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
9
200
60
598
9
400
40
607
9
1000
0
600
9
1200
0
612
9
2000
0
594
9
4000
0
584
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
10
200
280
551
10
400
40
581
10
1000
20
579
10
1200
5
544
10
2000
5
545
10
4000
5
531
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
11
200
40
628
11
400
0
640
11
1200
0
624
11
2000
0
614
11
4000
0
612
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
12
200
60
602
12
400
20
605
12
1200
0
628
12
2000
0
625
12
4000
0
621
[0071] The results summarized in the tables above show that—in contrast to the process described in EP 1 451 139 A1—an increase in the concentration of the tested additives does not lead to a decrease in bulk density or at least not to a significant decrease in bulk density.
Comparative Example 1
Recrystallization in the Presence of Anionic Surfactants
[0072] Recrystallization experiments were carried out with the anionic surfactants (13) sodium dodecylbenzenesulfonate and (14) dioctyl sodium sulfosuccinate known from JP 46 019610 B. Here, the pure surfactants were used in a concentration of 400 ppm each.
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
13
400
>400
348
14
400
0
446
[0073] The experimental data show that these surfactants lead to results which are worse than the results for the surfactants tested in Example 2.
Example 4
Recrystallization in the Presence of Nonionic Surfactants
[0074] Recrystallization experiments according to the procedure from Example 1 were carried out with the addition of nonionic surfactants. The following sorbitan based surfactants were used in the recrystallization experiments, where the surfactants were each used in a concentration of 400 ppm.
[0075] 15)Tego SMO V; sorbitan monooleate (PET10-084)
[0076] 16) Tego STO V; sorbitan trioleate (PET10-086)
[0077] 17) Tego SMS 60; polyethoxylated sorbitan monostearate (Pet 10-087)
[0078] 18) Tego SMS; sorbitan monostearate (Pet 10-088)
[0079] 19) Span 60; sorbitan monostearate (Pet 10-095)
[0080] 20) Span 80; sorbitan monooleate (Pet10-096)
[0081] 21) Span 83; sorbitan sesquioleate (Pet10-097)
[0082] 22) Span 65; sorbitan tristearate (Pet12-167)
[0083] 23) Tween 61; polyethoxylated (4 EO) sorbitan tristearate (Pet12-169)
[0084] 24) Tween 65; polyethoxylated (20 EO) sorbitan tristearate (Pet10-089)
[0000]
Concentration
Amount of foam
Bulk density
Additive
(ppm)
(ml)
(g/l)
15
400
0
356
16
400
0
483
17
400
320
526
18
400
0-5
346
19
400
0-5
345
20
400
0
335
21
400
0
356
22
400
60
446
23
400
20
499
24
400
0
616
[0085] With the non-ionic surfactant polyethoxylated sorbitan monostearate (Tween™ 65 from Croda) in a concentration of 400 ppm a methionine bulk density of 616 g/l was achieved.
Example 5
Influence of the Potassium Ion Concentration on the Bulk Density of Methionine
[0086] 1000 g of a 95° C.-hot solution of 100 g of methionine in 900 g of water were added dropwise, with stirring, to a 40° C.-warm suspension of 20 g of methionine in 180 g of water over 2 h, during which the temperature of the initial charge of suspension was kept at 40° C. The experiments were carried out in the presence of 400 ppm of total active ingredient content based on the total mass of the solution/suspension of a mixture according to the invention of a crystallization additive and of an antifoam and of an amount of potassium hydrogen carbonate corresponding to the potassium ion concentration given in the table. The mixture according to the invention of a crystallization additive and of an antifoam consisted of an aqueous solution of 6.1% by weight of silicone oil with a kinematic viscosity of 1000 mm 2 /s (AK 1000, Wacker-Chemie GmbH), 0.25% by weight of hydrophobicized silica (Sipernat D10, Evonik Degussa GmbH), 2.6% by weight of a polyethoxylated fatty acid mixture (Intrasol® FS 18/90/7, Ashland Deutschland GmbH), 3.7% by weight of a polyethoxylated fatty alcohol mixture (2.35% by weight of Marlipal®, Sasol Germany GmbH, 1.35% by weight of Brij C2, Croda Chemicals Europe) and 5.1% by weight of a fatty alcohol sulphate (Sulfopon® 1218 G, Oleochemicals) according to the formula:
[0000] C n H 2n+1 —O—SO 3 Na,
[0087] where n=12 to 18. The concentration of the pure crystallization additive was 117 ppm.
[0088] The bulk density of the precipitated methionine was determined after filtration and drying.
[0000]
K + concentration
Bulk density
(g/l)
(g/l)
0
160
2
560
4
590
8
570
10
570
12
560
14
540
[0089] The addition of potassium ions accordingly leads to an improvement in the bulk density even at a low concentration of the fatty alcohol sulphate used as crystallization additive.
|
This disclosure relates to a process for preparing D,L-methionine by feeding carbon dioxide to an aqueous potassium methioninate solution obtained by hydrolysis of 5-(2-methylmercaptoethyl)hydantoin, in order to precipitate out crude methionine, which is separated off and purified. In this process an aqueous solution of the separated-off crude methionine is purified by recrystallization from a solution containing potassium ions and also a crystallization additive. The crystallization additive is a nonionic or anionic surfactant, or a mixture of different nonionic or anionic surfactants. The recrystallization occurs by introducing a 60 to 110° C.-hot methionine solution into a 35 to 80° C.-warm methionine suspension, a temperature of which is lower than that of the introduced solution, such that the temperature of the methionine suspension being maintained between 35 and 80° C. during the addition. The crystallization additive is a sorbitan fatty acid ester or a mixture of different sorbitan fatty acid esters.
| 8
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FIELD OF THE INVENTION
[0001] This invention generally relates to the derivatives of 1-substituted-3-pyrrolidines.
[0002] The compounds of this invention can function as muscarinic receptor antagonists, and can be used for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors.
[0003] The invention also relates to a process for the preparation of the compounds of the present invention pharmaceutical compositions containing the compounds of the present invention and the methods for treating the diseases mediated through muscarinic receptors.
BACKGROUND OF THE INVENTION
[0004] Muscarinic receptors as members of the G Protein Coupled Receptors (GPCRs) are composed of a family of 5 receptor sub-types (M 1 , M 2 , M 3 , M 4 and M 5 ) and are activated by the neurotransmitter acetylcholine. These receptors are widely distributed on multiple organs and tissues and are critical to the maintenance of central and peripheral cholinergic neurotransmission. The regional distribution of these receptor sub-types in the brain and other organs has been documented. For example, the M 1 subtype is located primarily in neuronal tissues such as cereberal cortex and autonomic ganglia, the M 2 subtype is present mainly in the heart where it mediates cholinergically induced bradycardia, and the M 3 subtype is located predominantly on smooth muscle and salivary glands ( Nature, 1986; 323: 411; Science, 1987; 237: 527).
[0005] A review in Current Opinions in Chemical Biology 1999; 3: 426, as well as in Trends in Pharmacological Sciences, 2001; 22: 409 by Eglen et. al., describe the biological potentials of modulating muscarinic receptor subtypes by ligands in different disease conditions like Alzheimer's disease, pain, urinary disease condition, chronic obstructive pulmonary disease etc.
[0006] A review in J. Med. Chem., 2000; 43: 4333 by Christian C. Felder et. al. describes therapeutic opportunities for muscarinic receptors in the central nervous system and elaborates on muscarinic receptor structure and function, pharmacology and their therapeutic uses.
[0007] The pharmacological and medical aspects of the muscarinic class of acetylcholine agonists and antagonists are presented in a review in Molecules, 2001, 6: 142.
[0008] N. J. M. Birdsall et. al. in Trends in Pharmacological Sciences 2001; 22: 215 have also summarized the recent developments on the role of different muscarinic receptor subtypes using different muscaranic receptors of knock out mice.
[0009] Muscarinic agonists such as muscarine and pilocarpine and antagonists such as atropine have been known for over a century, but little progress has been made in the discovery of receptor subtype-selective compounds making it difficult to assign specific functions to the individual receptors. Although classical muscarinic antagonists such as atropine are potent bronchodilators, their clinical utility is limited due to high incidence of both peripheral and central adverse effects such as tachycardia, blurred vision, dryness of mouth, constipation, dementia, etc. Subsequent development of the quarterly derivatives of atropine such as ipratropium bromide are better tolerated than parenterally administered options but most of them are not ideal anti-cholinergic bronchodilators due to lack of selectivity for muscarinic receptor sub-types. The existing compounds offer limited therapeutic benefit due to their lack of selectivity resulting in dose limiting side-effects such as thirst, nausea, mydriasis and those associated with the heart such as tachycardia mediated by the M 2 receptor.
[0010] Annual review of Pharmacological Toxicol., 2001; 41: 691, describes the pharmacology of the lower urinary tract infections. Although anti muscarinic agents such as oxybutynin and tolterodine that act non-selectively on muscarinic receptors have been used for many years to treat bladder hyperactivity, the clinical effectiveness of these agents has been limited due to the side effects such as dry mouth, blurred vision and constipation. Tolterodine is considered to be generally better tolerated than oxybutynin. (W. D. Steers et. al. in Curr. Opin. Invest. Drugs, 2: 268, C. R. Chapple et. al. in Urology 55: 33), Steers W D, Barrot D M, Wein A J, 1996, Voiding dysfunction: diagnosis classification and management. In “Adult and Pediatric Urology,” ed. J Y Gillenwatter, J T Grayhack, S S Howards, J W Duckett, pp 1220-1325, St. Louis, Mo.; Mosby. 3 rd edition.)
[0011] Despite these advances, there remains a need for development of new highly selective muscarinic antagonists which can interact with distinct subtypes, thus avoiding the occurrence of adverse effects.
[0012] Compounds having antagonistic activity against muscarinic receptors have been described in Japanese patent application Laid Open Number 92921/1994 and 135958/1994; WO 93/16048; U.S. Pat. No. 3,176,019; GB 940,540; EP 0325 571; WO 98/29402; EP 0801067; EP 0388054; WO 9109013; U.S. Pat. No. 5,281,601. U.S. Pat. Nos. 6,174,900, 6,130,232 and 5,948,792; WO 97/45414 are related to 1,4-disubstituted piperidine derivatives; WO 98/05641 describes fluorinated, 1,4-disubstitued piperidine derivatives; WO 93/16018 and WO96/33973 are other close art references.
[0013] A report in J. Med. Chem., 2002; 44:984, describes cyclohexylmethyl piperidinyl triphenylpropioamide derivatives as selective M 3 antagonist discriminating against the other receptor subtypes.
[0014] PCT applications WO 98/00109; 98/00132; 98/00133 and 98/00016 disclose isomers of glycopyrolate.
SUMMARY OF THE INVENTION
[0015] The present invention provides 1-substituted-3-pyrrolidines which function as muscarinic receptor antagonists and are useful as safe and effective therapeutic or prophylactic agents for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems and process for the synthesis of the compounds.
[0016] The invention also provides pharmaceutical compositions containing the compounds, and which may also contain acceptable carriers, excipients or diluents which are useful for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems.
[0017] The invention also includes the enantiomers, diastereomers, polymorphs, pharmaceutically acceptable salts, pharmaceutically acceptable solvates, esters, N-oxides and metabolites of these compounds having the same type of activity.
[0018] The invention further includes pharmaceutical compositions comprising the compounds of the present invention, their esters, metabolites, enantiomers, diastereomers, N-oxides, polymorphs, pharmaceutically acceptable salts or pharmaceutically acceptable solvates, in combination with a pharmaceutically acceptable carrier and optionally included excipients.
[0019] Other advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description or may be learnt by the practice of the invention. The objects and the advantages of the invention may be realized and obtained by means of the mechanisms and combinations pointed out in the appended claims.
[0020] In accordance with one aspect of the present invention, there is provided a compound having the structure of Formula I:
and its pharmaceutically acceptable salts, pharmaceutically acceptable solvates, esters, enantiomers, diastereomers, N-oxides, polymorphs, prodrugs, or metabolites, wherein
X represents an oxo, amino, lower alkyl(C 1 -C 4 )amino or lower alkoxy (C 1 -C 4 ); R 1 represents hydroxy, amino, or alkoxy (OR 7 ), wherein R 7 represents lower alkyl; R 2 represents hydrogen, halogen (e.g. fluorine, chlorine, bromine and iodine) or lower alkyl; R 3 represents hydrogen, keto, hydroxy, sulphonyl methane, tosyl, azide, amino or substituted amine (N 8 ) where R 8 represents hydrogen or YR 9 , wherein R 9 represents benzyl, benzyloxy, alkyl, benzyl ether, phenyl optionally substituted with alkyl, trifluoromethyl, nitro or halogen (e.g. fluorine, chlorine, bromine, iodine); Z represents methylene, sulphonyl or carbonyl; W represents a direct link of (CH 2 ) n , where n is 1 or 2, lower alkoxy (C 1 -C 4 ) or lower thioalkoxy (C 1 -C 4 ); R represents alkyl, aryl, aralkyl, benzyl ether, dimethyl ether, methoxy methyl, benzyl methyl ether or phenyl optionally substituted with alkyl, halogen (e.g. fluorine, chlorine, bromine, iodine), nitro, heterocycle selected from the group consisting of pyridinyl, pyrazinyl or thienyl;
wherein X′ and X″ are each independently selected from the group consisting of oxygen, methylene; m represents 1 to 3; and
R 4 , R 5 and R 6 represent hydrogen or lower alkyl.
[0030] In accordance with a second aspect of the present invention, there is provided a method for treatment or prophylaxis of an animal or human suffering from a disease or disorder of the respiratory, urinary and gastrointestinal systems, wherein the disease or disorder is mediated through muscarinic receptors, comprising administering to a patient in need thereof, an effective amount of compounds as described above.
[0031] In accordance with a third aspect of the present invention, there is provided a method for treatment or prophylaxis of an animal or human suffering from a disease or disorder associated with muscarinic receptors, comprising administering to a patient in need thereof, an effective amount of compounds as described above.
[0032] In accordance with a fourth aspect of the present invention, there is provided a method for treatment or prophylaxis of an animal or human suffering from a disease or disorder of the urinary system which induce such urinary disorders as urinary incontinence, lower urinary tract symptoms (LUTS), etc.; respiratory system such as bronchial asthma, chronic obstructive pulmonary disorders (COPD), pulmonary fibrosis, etc; and gastrointestinal system such as irritable bowel syndrome, obesity, diabetes and gastrointestinal hyperkinesis with compounds as described above, wherein the disease or disorder is associated with muscarinic receptors.
[0033] In accordance with a fifth aspect of the present invention, there is provided a process for preparing the compounds as described above.
[0034] The compounds of the present invention exhibit significant potency in terms of their activity, which was determined by in vitro receptor binding and functional assays and in vivo experiments using anaesthetized rabbit. Compounds were tested in vitro and in vivo. Some compounds were found to function as potent muscarinic receptor antagonists with high affinity towards M 3 receptors. Therefore, the present invention provides pharmaceutical compositions for treatment of the diseases or disorders associated with muscarinic receptors. Compounds and compositions described herein can be administered orally or parenterally.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The compounds described herein may be prepared by techniques well known in the art and familiar to the average synthetic organic chemist. In addition, the compounds described herein may be prepared by the following reaction sequence:
[0036] The compounds of Formula I of the present invention may be prepared by the reaction sequence as shown in scheme I. The preparation comprises coupling a compound of Formula II with the compound of Formula III wherein
X represents an oxo, amino, lower alkyl(C 1 -C 4 )amino or lower alkoxy (C 1 -C 4 ); R 1 represents hydroxy, amino, or alkoxy (OR 7 ), wherein R 7 represents lower alkyl; R 2 represents hydrogen, halogen (e.g. fluorine, chlorine, bromine and iodine) or lower alkyl; R 3 represents hydrogen, keto, hydroxy, sulphonyl methane, tosyl, azide, amino or substituted amine (NHR 8 ) where R 8 represents hydrogen or YR 9 , wherein R 9 represents benzyl, benzyloxy, alkyl, benzyl ether, phenyl optionally substituted with alkyl, trifluoromethyl, nitro or halogen (e.g. fluorine, chlorine, bromine, iodine); R 4 , R 5 and R 6 represent hydrogen or lower alkyl; N is 1 or 2; and P is any group, for example benzyl, t-buyloxycarbonyl, which can be used to protect an amino group in the presence of a coupling agent to give a protected compound of Formula IV, which on deprotection through reaction with a deprotecting agent in an organic solvent gives an unprotected compound of Formula V which is finally N-alkylated, carbonylated or sulphonylated with a suitable alkylating, carbonylating or sulphonylating agent of Formula L-Z-W-R to give a compound of Formula I, wherein L is a leaving group and Z represents methylene, sulphonyl or carbonyl; W represents a direct link of (CH 2 ) n , where n is 1 or 2, lower alkoxy (C 1 -C 4 ) or lower thioalkoxy (C 1 -C 4 ); and R represents alkyl, aryl, aralkyl, benzyl ether, dimethyl ether, methoxy methyl, benzyl methyl ether or phenyl optionally substituted with alkyl, halogen (e.g. fluorine, chlorine, bromine, iodine), nitro, heterocycle selected from the group consisting of pyridinyl, pyrazinyl or thienyl;
wherein X′ and X″ are each independently selected from the group consisting of oxygen, methylene; and m represents 1 to 3.
[0048] The reaction of the compound of Formula II with a compound of Formula III to give a compound of Formula IV can be carried out in the presence of a coupling agent, for example, N-methyl morpholine, hydroxy benzotriazole,1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride (EDC. HCL) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).
[0049] The reaction of the compound of Formula II with a compound of Formula III to give a compound of Formula IV can be carried out in a suitable solvent, for example, N,N-dimethylformamide, chloroform, dimethylsulphoxide, xylene and toluene.
[0050] The deprotection of the compound of Formula IV to give a compound of Formula V can be carried out in the presence of a deprotecting agent, for example, palladium on carbon, ammonium formate, trifluoroacetic acid and hydrochloric acid.
[0051] The deprotection of the compound of Formula IV to give a compound of Formula V can be carried out in a suitable solvent, for example, methanol, ethanol, tetrahydrofuran and acetonitrile at temperatures ranging from about 10 to about 50° C.
[0052] The N-alkylation, carbonylation or sulphonylation of the compound of Formula V to give a compound of Formula I can be carried out with a suitable alkylating, carbonylating, or sulphonylating agent, L-Z-W-R where L is any leaving group known in the art, for example halogen, O-mestyl, benzyl and O-tosyl group.
[0053] The N-alkylation or carbonylation or sulphonylation of the compound of Formula V to give a compound of Formula I can be carried out in a suitable solvent such as N,N-dimethylformamide, dimethylsulfoxide, tetrahydrofuran, acetonitrile and dichloromethane.
[0054] In the above scheme, where specific bases, coupling agents, protecting groups, deprotecting agents, N-alkylating, sulphonylating, cabonylating agents, solvents, catalysts etc. are mentioned, it is to be understood that other bases, coupling agents deprotecting agents, N-alkylating, sulphonylating, carbonylating agents, solvents etc. known to those skilled in art may be used. Similarly, the reaction temperature and duration may be adjusted according to the desired needs.
[0055] The pharmaceutically acceptable salts of the compounds of Formula I include acid addition salts such as hydrochloride, hydrobromide, hydrofluoric, sulphate, bisulfate, phosphate, hydrogen phosphate, acetate, brosylate, citrate, fumarate, glyconate, lactate, maleate, mesylate, succinate, and tartarate.
[0056] Quaternary ammonium salts such as alkyl salts, aralkyl salts, and the like, of the organic bases may be readily formed by treatment of the organic bases with the appropriate quaternary salts forming substances, which include, for example methyl chloride, methyl bromide, methyl iodide, methyl sulphate, methyl benzene sulphonate, methyl p-toluene sulphonate, ethyl chloride, ethyl bromide, ethyl iodide, n-propyl chloride, n-propyl bromide, n-propyl iodide, isopropyl bromide, n-butyl chloride, n-butyl bromide, isobutyl bromide, sec-butylbromide, n-amyl bromide, n-hexyl chloride, benzyl chloride, benzyl bromide, and ethyl sulphate.
[0057] Particular compounds which are capable of being produced by Scheme I and shown in Table I include:
[0000] Compound No. Chemical Name
[0000]
1. 2-cyclopentyl-2-hydroxy-N-[(3S)-1-benzyl-pyrrolidin-3-yl]-2-phenyl acetamide
2. 2-cyclopentyl-2-hydroxy-N-[(3S)-1-[2-(1,3-benzodioxol-5-yl)]-ethyl]pyrrolidin-3-yl]-2-phenyl acetamide
3. (3S)-1-benzylpyrrolidin-3-yl cyclopentyl(hydroxy)phenyl acetate
4. (3S)-1-[[2-(,3-benzodioxol-yl)ethyl]pyrrolidin-3yl]cyclopentyl(hydroxy)phenyl acetate
5. (3S)-1-[[2-(2,3-dihydro-1-benzofuran-5-yl)ethyl]pyrrolidin-3-yl]cyclopentyl-(hydroxy)phenyl acetate
6. (3S)-1-[(4-methyl-pent-3-enyl)pyrrolidin-3-yl] cyclopentyl(hydroxy)phenyl acetate
7. (3S)-1-[(4-trifluoromethylphenyl)sulfonyl]pyrrolidin-3-yl]cyclopentyl(hydroxy) phenyl acetate
8. (3S)-1-[(4-nitrophenyl]sulfonyl]pyrrolidin-3-yl]cyclopentyl(hydroxy)phenyl acetate
9. (3S)-1-benzyl-pyrrolidin-3-yl (2R)-hydroxy(3-oxocyclopentyl)phenyl acetate
10. (3S)-1-benzylpyrrolidin-3-yl (2R)-hydroxy(3-hydroxycyclopentyl)phenyl acetate
11. (3S)-1-[(phenylacetyl)pyrrolidin-3-yl] cyclopentyl(hydroxy)phenyl acetate
12. (3S)-1-[(benzyloxy)acetyl)pyrrolidin-3-yl]cyclopentyl(hydroxy)phenyl acetate
13. Benzyl (3S)-3-[(2-hydroxy-2-cyclopentyl-2-phenylpropanoyl)oxy]pyrrolidin-1-carboxylate
14. (3S)-1-[(4-bromophenyl)sulfonyl]pyrrolidin-3-yl]cyclopentyl(hydroxy)phenyl acetate
15. (3S)-1-benzylpyrrolidin-3-yl (2R)-cyclopentyl(hydroxy)phenyl acetate
16. (3S)-1-[[2-(2,3-dihydro-1-benzofuran-5-yl)ethyl]pyrrolidin-3-yl] (2R)cyclopentyl(hydroxy)phenyl acetate
[0074] 17. (3S)-1-[[2-(1,3-benzodioxol-5-yl)ethyl]pyrrolidin-3-yl (2R)-cyclopentyl(hydroxy) phenyl acetate
TABLE I Formula I Configuration at Compound Configuration at Carbon attached No. Z—W—R X R 3 pyrrolidine to R 1 1. NH H S RS 2 NH H S RS 3. O H S RS 4. O H S RS 5. O H S RS 6. O H S RS 7. O H S RS 8. O H S RS 9. O CO S RS 10. O OH S RS 11. O H S RS 12. O H S RS 13. O H S RS 14. O H S RS 15. O H S R 16. O H S R 17. O H S R
[0075] Compounds or compositions disclosed may be administered to an animal for treatment orally, or by a parenteral route. Pharmaceutical compositions disclosed herein can be produced and administered in dosage units, each unit containing a certain amount of at least one compound described herein and/or at least one physiologically acceptable addition salt thereof. The dosage may be varied over extremely wide limits as the compounds are effective at low dosage levels and relatively free of toxicity. The compounds may be administered in the low micromolar concentration, which is therapeutically effective, and the dosage may be increased as desired up to the maximum dosage tolerated by the patient.
[0076] The present invention also includes the enantiomers, diastereomers, N-oxides, polymorphs, solvates and pharmaceutically acceptable salts of these compounds as well as metabolites having the same type of activity. The present invention further includes pharmaceutical composition comprising the compounds of Formula I, their esters, metabolites, enantiomers, diastereomers, N-oxides, polymorphs, solvates or pharmaceutically acceptable salts thereof, in combination with pharmaceutically acceptable carrier and optionally included excipients.
[0077] The examples mentioned below demonstrate the general synthetic procedure as well as the specific preparation of the preferred compounds. The examples are provided to illustrate particular aspects of the disclosure and should not be constrained to limit the scope of the present invention as defined by the claims.
EXPERIMENTAL DETAILS
[0078] Various solvents, such as acetone, methanol, pyridine, ether, tetrahydrofuran, hexane and dichloromethane were dried using various drying reagents according to the procedures well known in the literature. IR spectra were recorded as nujol mulls or a thin neat film on a Perkin Elmer Paragon instrument, Nuclear Magnetic Resonance (NMR) were recorded on a Varian XL-300 MHz instrument using tetramethylsilane as an internal standard.
Example 1
Preparation of 2-cyclopentyl-2-hydroxy-N-[(3S)-1-benzyl-pyrrolidin-3-yl]-2-phenylacetamide (Compound No. 1)
Step 1: Preparation of (3R)-pyrrolidin-3-ol hydrochloride
[0079] The compound trans-4-hydroxy-L-proline (10.0 g, 76.3 mM) was taken in a mixture of anhydrous cyclohexanol (50.0 ml) and 2-cyclohexen-1-one (0.5 ml). The reaction mixture was heated at 155-160° C. for about 11 hours. To the reaction mixture, ethanolic hydrochloric acid (70.0 ml) was added with constant stirring, and kept at 0-5° C. overnight. The separated solid was filtered under nitrogen atmosphere, washed with ethyl acetate (10.0 ml) and dried under vacuum to get the title compound. Yield=35% (3.3 g, 26.7 mM).
[0080] 1 H NMR (DMSO-d 6 ): δ 9.57 (brs, 1H), 9.33 (brs, 1H), 5.00-5.75 (brs, 1H), 4.38 (s, 1H), 3.01-3.47 (m, 4H), 1.84-1.92 (m, 2H).
Step 2: Preparation of (3R)-1-benzyl-pyrrolidin-3-ol
[0081] The compound (3R)-pyrrolidin-3-ol hydrochloride (2.2 g, 17.8 mM) was dissolved in dichloromethane (25.0 ml) and triethylamine (5.0 ml, 35.6 mM) was added at room temperature with constant stirring for 5 minutes. Benzyl chloride (2.5 ml, 21.4 mM) was added to it in one lot at the same temperature followed by refluxing for 15 hours. The reaction mixture was diluted with chloroform and 1N sodium hydroxide (15.0 ml) was added with constant stirring for 10 minutes. The organic layer was separated and washed with aqueous sodium bicarbonate and brine solution. It was further dried over anhydrous sodium sulphate and concentrated to get the title compound. Yield=44.4% (1.4 g, 7.9 mM).
[0082] 1 H NMR (CDCl 3 ): δ 7.31-7.37 (m, 5H), 4.36-4.37 (m, 1H), 3.68 (s, 1H), 2.73-2.92 (m, 1H), 2.72 (d, J=10 Hz, 1H), 2.56-2.61 (m, 1H), 2.20-2.37 (m, 2H), 1.77-1.81 (m, 1H).
Step 3: Preparation of (3R)-1-benzyl-3-[(methylsulfonyl) oxy]pyrrolidine
[0083] The compound (3R)-1-benzyl-pyrrolidin-3-ol (1.0 g, 5.65 mM) was dissolved in triethylamine (2.0 ml, 14.3 mM), and dimethyl amino pyridine (DMAP) (0.002 g), dichloromethane (20.0 ml) and methanesulfonyl chloride (0.9 ml, 11.7 mM) was added dropwise at 0-5° C. The reaction mixture was maintained at the same temperature for about half an hour. The reaction mixture was then stirred at room temperature for 2 hours. The reaction mixture was diluted with dichloromethane (50.0 ml), washed with saturated sodium bicarbonate and brine solution. It was further dried over anhydrous sodium sulphate and concentrated to get the title compound as oil. Yield=95% (1.2 g, 5.38 mM). This material was used as such in the next step.
Step 4: Preparation of (3S)-1-benzyl-3-azidopyrrolidine
[0084] The compound (3R)-1-benzyl-3-[(methylsulfonyl) oxy]pyrrolidine (1.3 g, 5.8 mM) was dissolved in dimethylformamide (25.0 ml) and sodium azide (1.5 g, 23.3 mM) was added to it. The reaction mixture was maintained at 90-100° C. for about 12 hours followed by cooling at room temperature. The reaction mixture was poured into cold water (150.0 ml) with constant stirring. The organic compound was extracted with ethyl acetate and washed with water and brine solution, dried over anhydrous sodium sulphate and concentrated to give the title compound. Yield=78% (0.9 g, 4.5 m. This material was used as such in the next step.
[0085] IR (DCM): 2100.8 cm −1 .
Step 5: Preparation of (3S)-1-benzyl-3-aminopyrrolidine
[0086] The compound (3S)-1-benzyl-3-azidopyrrolidine (0.9 g, 4.5 mM) was dissolved in a mixture of tetrahydrofuran (36.0 ml) and water (7.0 ml). To it, triphenylphosphine (2.3 g, 8.9 mM) was added and the reaction mixture was refluxed for 7 hours. The reaction mixture was cooled to room temperature and tetrahydrofuran was evaporated under vacuum. The residue was taken in water (50.0 ml) and the pH was adjusted to about 2 and washed with chloroform. The pH of the aqueous solution was adjusted to about 12-13 with 1N sodium hydroxide and extracted with chloroform. The chloroform layer was washed with water and brine solution. It was further dried over anhydrous sodium sulphate and concentrated to give the title compound. Yield=62% (0.5 g, 2.8 mM).
[0087] 1 HNMR (CDCl 3 ): δ 7.21-7.32 (m, 5H), 3.60 (d, J=4.3 Hz, 2H), 3.49-3.51 (m, 1H), 2.68-2.74m, 2H), 2.46-2.48 (m, 1H), 2.18-2.33 (m, 2H), 1.61 (s, 2H, —NH 2 ), 1.48-1.50 (m, 1H).
Step 6: Preparation of 2-cyclopentyl-2-hydroxy-N-[(3S)-1-benzyl-pyrrolidin-3-yl]-2-phenylacetamide (Compound No. 1)
[0088] The compound 2-cyclopentyl-2-hydroxy-2-phenylacetic acid (0.52 g, 2.36 mM) and (3S)-1-benzyl-3-aminopyrrolidine (0.5 g, 2.84 mM) were dissolved in dimethylformamide (10.0 ml) and N-methylmorpholine (1.3 ml, 11.8 mM) was added into it followed by the addition of 1-hydroxybenzotriazole (0.32 g, 2.36 mM) at 0-5° C. The reaction mixture was maintained at 0-5° C. for 1 hour and then at room temperature for 19 hours. The reaction mixture was poured into water (100.0 ml) with constant stirring. The organic compound was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated sodium bicarbonate water and brine solution followed its drying and concentration over anhydrous sodium sulphate. The residue was purified by silica gel column chromatography using 10% methanol in chloroform to get the title compound. Yield=95% (0.5 g, 2.38 mM).
[0089] 1 H NMR (CDCl 3 ): δ 7.58-7.60 (m, 2H), 7.26-7.36 (m, 8H), 6.74-6.80 (m, —CONH), 4.32-4.35 (m, 1H), 3.54-3.62 (m, 2H), 2.79-3.00 (m, 3H), 2.47-2.49 (brs, 1H, OH), 2.09-2.28 (m, 2H), 1.54-1.62 (m, 9H).
Example 2
Preparation of 2-cyclopentyl-2-hydroxy-N-[(3S)-1-[2-(1,3-benzodioxol-5-yl)ethyl]pyrrolidin-3-yl]-2-phenylacetamide (Compound No. 2)
Step 1: Preparation of 2-cyclopentyl-2-hydroxy-N-[(3S)-pyrrolidin-3-yl]-2-phenylacetamide
[0090] The compound 2-cyclopentyl-2-hydroxy-N-[(3S)-1-benzyl-pyrrolidin-3-yl]-2-phenyl-acetamide (0.8 g, 2.12 mM) was dissolved in methanol (20.0 ml) and 10% palladium on carbon (0.2 g) is added. After hydrogenating at room temperature for 10 hours at 65-70 psi, the second lot of 10% palladium on carbon (0.2 g) was added and hydrogenation was continued for 10 more hours at 65-70 psi at room temperature. The reaction mixture was diluted with methanol and filtered through a bed of hyflo. The filtrate was concentrated under vacuum and used as such in the next step.
Step 2: Preparation of 2-cyclopentyl-2-hydroxy-N-[(3S)-1-[2-(1,3-benzodioxol-5-yl)ethyl]pyrrolidin-3-yl]-2-phenylacetamide (Compound No. 2)
[0091] The compound 2-cyclopentyl-2-hydroxy-N-[(3S)-pyrrolidin-3-yl)]-2-phenylacetamide (0.3 g, 1.04 mM) was dissolved in acetonitrile (5.0 ml). To this, 5-(2-bromoethyl)-1,3-benzodioxole (0.28 g, 1.25 mM), potassium carbonate (0.43 g, 3.12 mM) and potassium iodide (0.34 g, 2.8 mM) were added and the reaction mixture was heated under reflux for 9 hours. The reaction mixture was cooled to room temperature and acetonitrile was evaporated under vacuum. The residue was partitioned between ethyl acetate (50.0 ml) and water (50.0 ml). The ethyl acetate layer was washed with water and brine solution and dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel colum chromatography using 20% methanol in chloroform to get the title organic compound as an oil. Yield=64% (0.29 g, 0.67 mM).
[0092] 1 H NMR (CDCl 3 ): δ 7.60 (d, J=7.5 Hz), 7.28-7.36 (m, 3H), 6.88 (br s, 1H, —CONH), 6.58-6.75 (m, 3H), 5.92 (d, J=1 Hz, 2H), 4.36-4.38 (m, 1H), 3.35-3.65 (brm, 1H), 2.88-3.03 (brm, 2H), 2.60-2.66 (m, 4H), 2.53 (m, 1H), 2.23-2.25 (m, 2H), 1.80 (brs, 1H, —OH), 1.55-1.66 (m, 9H).
Example 3
Preparation of (3S)-1-benzyl-pyrrolidin-3-yl cyclopentyl (hydroxy) phenylacetate (Compound No. 3)
[0093] The compound 2-cyclopentyl-2-hydroxy-2-phenylacetic acid (0.3 g, 1.36 mM), (3R)-1-benzyl-pyrrolidin-3-ol (0.2 g, 1.14 mM) and triphenylphosphine (0.36 g, 1.36 mM) were dissolved in dry tetrahydrofuran (10.0 ml). To this, a solution of diethylazabicyclocarboxylate (0.2 ml, 1.36 mM) in dry tetrahydrofuran (2.0 ml) was added dropwise under nitrogen atmosphere at room temperature with constant stirring and the stirring was continued for 20 hours. Tetrahydrofuran was evaporated under vacuum and the residue was taken in chloroform and washed with saturated sodium bicarbonate solution, water and brine solution followed by drying and concentrating over anhydrous sodium sulphate. The residue was purified by silica gel column chromatography using 30% ethyl acetate in hexane to get the title compound as oil. Yield=91% (0.39 g, 1.03 mM).
[0094] 1 H NMR (CDCl 3 ): δ 7.64-7.67 (m, 2H), 7.26-7.35 (m, 8H), 5.17-5.23 (m, 1H), 3.56-3.74 (m, 3H), 2.75-2.90 (m, 4H), 2.00-2.52 (m, 3H, including-OH), 1.29-2.00 (m, 8H).
Example 4
Preparation of (3S)-1-[[2-(1,3-benzodioxol-5-yl)ethyl]pyrrolidin-3-yl]cyclopentyl(hydroxy)-phenylacetate (Compound No. 4)
Step 1: Preparation of (3S)-pyrrolidin-3-yl cyclopentyl (hydroxy) phenylacetate
[0095] The compound (3S)-1-benzylpyrrolidin-3-yl cyclopentyl (hydroxy) phenylacetate (2.8 g, 7.4 mM) was dissolved in methanol (50.0 ml) and 10% palladium on carbon was added (0.28 g) followed by the addition of ammonium formate (1.5 g, 23.8 mM) under nitrogen atmosphere. The reaction mixture was maintained at 40-50° C. for 2 hours. One more lot of ammonium formate (1.5 g, 23.8 mM) was added and the reaction mixture was maintained at the same temperature for one more hour. The reaction mixture was cooled to room temperature and filtered through a bed of hyflo. The filtrate was evaporated under vacuum and the residue was taken in ethyl acetate and washed with water and brine solution and dried over anhydrous sodium sulphate and concentrated. It was used as such in the next step.
Step 2: Preparation of (3S)-1-[[2-(1,3-benzodioxol-5-yl)ethyl]pyrrolidin-3-yl]cyclopentyl(hydroxy)-phenylacetate (Compound No. 4)
[0096] The compound (3S)-pyrrolidine-3-yl cyclopentyl (hydroxy) phenylacetate (0.19 g, 0.66 mM) was dissolved in acetonitrile (5.0 ml) and 5-(2-bromoethyl)-1,3-benzodioxole (0.18 g, 0.79 mM) was added. To the reaction mixture, potassium carbonate (0.28 g, 1.97 mM) and potassium iodide (0.22 g, 1.31 mM) were added. The reaction mixture was heated under reflux for 9 hours. The reaction mixture was cooled to room temperature and acetonitrile was evaporated under vacuum. The residue was partitioned between ethyl acetate (30.0 ml) and water (30.0 ml). The organic layer was washed with water and brine solution followed by drying over anhydrous sodium sulphate and then concentrated. The residue was purified by silica gel column chromatography using 20% methanol in chloroform to get the title compound as oil. Yield=52% (0.15 g, 0.34 mM).
[0097] 1 H NMR (CDCl 3 ): δ 7.65 (d, J=7.4 Hz, 2H), 7.30-7.35 (m, 3H), 6.61-6.74 (m, 3H), 5.92 (s, 2H), 5.21-5.23 (m, 1H), 3.78 (s, 1H), 2.54-2.92 (m, 7H), 2.05-2.45 (m, 2H), 1.83 (brss, —OH), 1.25-1.64 (m, 9H).
Example 5
Preparation of (3S)-1-[[2-(2,3-dihydro-1-benzofuran-5-yl)ethyl]pyrolidin-3-yl]cyclopentyl(hydroxy)phenylacetate (Compound No. 5)
[0098] The compound (3S)-pyrrolidin-3-yl cyclopentyl (hydroxy) phenylacetate (0.2 g, 0.69 mM) was dissolved in acetonitrile (5.0 ml) followed by the addition of 5-(2-bromoethyl)-2,3-dihydro-1-benzofuran (0.173 g, 0.76 mM), potassium carbonate (0.29 g, 2.01 mM) and potassium iodide (0.23 g, 1.38 mM). The reaction mixture was heated under reflux for 8 hours and then cooled to room temperature. Acetonitrile was evaporated under vacuum. The residue was partitioned between ethyl acetate (30.0 ml) and water (30.0 ml). The organic layer was washed with water and brine solution followed by drying over anhydrous sodium sulphate. The residue was purified by silica get column chromatography using 10% methanol in chloroform to get the title compound as oil. Yield=50% (0.15 g, 0.34 mM).
[0099] 1 H NMR (CDCl 3 ): δ 7.66 (d, J=7 Hz, 2H), 7.31-7.36 (m, 3H), 7.03 (d, J=8 Hz, 1H), 6.93 (t, J=8 Hz, 1H), 6.69-672 (m, 1H), 5.22-5.24 (m, 1H), 4.55 (t, J=9 Hz, 2H), 3.76 (br m, 1H), 3.18 (t, J=9 Hz, 2H), 2.54-2.92 (m, 8H), 2.00-2.50 (m, 1H), 1.25-1.63 (m, 10OH, including —OH).
Example 6
Preparation of (3S)-1-[(4-methyl-pent-3-enyl) pyrrolidin-3-yl]cyclopentyl (hydroxy)-phenylacetate (Compound No. 6)
[0100] The compound (3S)-pyrrolidin-3-yl cyclopentyl (hydroxy) phenylacetate (0.2 g, 0.69 mM) was dissolved in acetonitrile (5.0 ml) and 4-methyl-pent-3-enyl bromide (0.13 ml, 0.76 mM), potassium carbonate (0.29 g, 2.01 mM) and potassium iodide (0.23 g, 1.38 mM) were added into it. The reaction mixture was heated under reflux for 8 hours followed by cooling to room temperature. Acetonitrile was evaporated under vacuum. The residue was partitioned between ethyl acetate (30.0 ml) and water (30.0 ml). The organic layer was washed with water and brine solution. It was then dried over anhydrous Na 2 SO 4 and concentrated. The residue was purified by silica gel column chromatography using 10% methanol in chloroform to get the title compound. Yield=54% (0.14 g, 0.38 mM) yield.
[0101] 1 H NMR (CDCl 3 ): δ 7.55-7.66 (m, 2H), 7.30-7.34 (m, 3H), 5.60 (m, 1H), 5.06-5.24 (m, 1H), 4.32-4.71 (m, 2H), 3.58-3.75 (m, 3H), 2.83-3.25 (m, 3H), 2.22-2.33 (m, 3H, including —OH), 1.26-1.79 (m, 15H).
Example 7
Preparation of (3S)-1-[[4-trifluoromethylphenyl) sulfonyl]pyrrolidin-3-yl]cyclopentyl(hydroxy) phenylacetate (Compound No. 7)
[0102] The compound (3S)-pyrrolidin-3-yl cyclopentyl (hydroxy) phenyl acetate (0.2 g, 0.69 mM) was dissolved in chloroform (10.0 ml) and triethylamine (0.19 ml, 1.38 mM) and dimethylaminopyridine (0.001 g) were subsequently added. The reaction mixture was cooled at 0-5° C. 4-(trifluoromethyl) benzenesulfonyl chloride (0.2 g, 083 mM) was added to it and maintained for 2 hours at the same temperature and then at room temperature for overnight. The reaction mixture was diluted and the organic layer was washed with water and brine solution. It was finally dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 40% ethyl acetate in hexane to get the title compound. Yield=70% (0.24 g, 0.48 mM).
[0103] 1 H NMR (CDCl 3 ): δ 7.97-7.99 (m, 2H), 7.83-7.87 (m, 2H), 7.27-7.42 (m, 5H), 5.22-5.28 (brm, 1H), 3.32-3.57 (m, 6H), 2.50-2.75 (m, 1H), 2.08-2.10 (brss, 1H), 1.26-1.82 (m, 8H).
Example 8
Preparation of (3S)-1-[[4-nitrophenyl) sulfonyl]pyrrolidin-3-yl]cyclopentyl (hydroxy)phenyl acetate (Compound No. 8)
[0104] The compound (3S)-pyrrolidin-3-yl cyclopentyl (hydroxy) phenylacetate (0.2 g, 0.69 mM) was dissolved in chloroform (10.0 ml). To the reaction mixture triethylamine (0.19 ml, 1.38 mM) and dimethylaminopyridine (0.001 g) were added and cooled the resulting reaction mixture to 0-5° C. 4-(nitro) benzenesulfonyl chloride (0.184 g, 083 mM) was added to it and maintained for 2 hour and the reaction was quenched by adding saturated sodium bicarbonate solution (5.0 ml). The organic layer was washed with water and brine solution, which was dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 40% ethyl acetate in hexane to get the title compound. Yield=76% (0.25 g, 0.53 mM).
[0105] 1 H NMR (CDCl 3 ): δ 8.37-8.43 (m, 2H), 7.99-8.07 (m, 2H), 7.29-7.44 (m, 5H), 5.23-5.27 (m, 1H), 3.28-3.60 (m, 6H), 2.50-2.75 (m, 1H), 2.10-2.13 (brs, 1H), 1.23-1.60 (m, 8H).
Example 9
Preparation of (3S)-1-benzylpyrrolidin-3-yl (2R)-hydroxy (3-oxocyclopentyl) phenyl acetate (Compound No. 9)
[0106] The compounds (2R)-hydroxy (3-oxocyclopentyl) phenylacetic acid (1.0 g, 4.27 mM), (3R)-1-benzyl-pyrrolidin-3-ol (0.63 g, 3.56 mM) were dissolved in dry tetrahydrofuran (30 ml) and triphenylphosphine (1.12 g, 4.27 mM). To the reaction mixture, a solution of diethylazoldicarboxyate (0.7 ml, 4.27 mM) in dry tetrahydrofuran (4.0 ml) was added dropwise under nitrogen atmosphere at room temperature with constant stirring and stirring was continued for 20 hours at the same temperature. Tetrahydrofuran was evaporated under vacuum and the residue was purified by silica gel column chromatography using 35% ethyl acetate in hexane to get the title compound. Yield=11% (0.18 g, 0.46 mM).
[0107] 1 H NMR (CDCl 3 ): δ 7.61-7.67 (m, 2H), 7.30-7.40 (m, 8H), 5.18-5.23 (m, 1H), 3.88 (brs, —OH), 3.57-3.70 (m, 2H), 3.21 (m, 1H), 2.68-2.80 (m, 3H), 2.39-2.44 (m, 1H), 2.12-2.27 (m, 4H), 1.61-1.81 (m, 4H).
Example 10
Preparation of (3S)-1-benzylpyrrolidin-3-yl (2R)-hydroxy (3-hydroxycyclopentyl) phenyl acetate (Compound No. 10)
[0108] The compound (3S)-1-benzylpyrrolidin-3-yl (2R)-hydroxy (3-oxocyclopentyl) phenylacetate (0.5 g, 1.27 mM) was dissolved in methanol (25.0 ml). To the reaction mixture, sodium borohydride (0.24 g, 6.36 mM) was added in several portions at −78° C. and maintained the resulting reaction mixture at the same temperature for 1 hour. The reaction mixture was diluted with water (10.0 ml) and brought to room temperature. Methanol was removed under vacuum and the organic layer was extracted with chloroform. The organic layer was washed with water and brine solution and dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 60% ethyl acetate in hexane to get the title compound. Yield=46% (0.23 g, 0.58 mM).
[0109] 1 H NMR (CDCl 3 ): δ 7.63 7.66 (m, 2H), 7.28-7.37 (m, 8H), 5.19-5.22 (m, 1H), 4.35 (br s, secondary —OH), 4.11-4.19 (m, 1H), 3.55-3.72 (m, 2H), 3.25 (m, 1H), 2.66-2.82 (m, 3H), 2.45 (m, 1H), 2.17-2.20 (m, 1H), 1.95 (m, 1H), 1.42-1.82 (m, 7H, including quaternary —OH).
Example 11
Preparation of (3S)-1-[(phenyl acetyl)]pyrrolidin-3-yl cyclopentyl(hydroxy)phenyl acetate (Compound NO. 11)
[0110] The compound (3S)-pyrrolidin-3-yl cyclopentyl (hydroxy) phenyl acetate (0.2 g, 0.69 mM) was dissolved in chloroform (10.0 ml). To the reaction mixture, triethylamine (0.19 ml, 1.38 mM) and dimethyl amino pyridine (DMAP) (0.001 g) were added and cooled to 0-5° C. Phenyl acetyl chloride (0.12 ml, 0.83 mM) was added to it and maintained the resulting mixture at the same temperature for 2 hours and then at room temperature overnight. The reaction mixture was diluted with chloroform and the reaction was quenched by adding saturated sodium bicarbonate solution (5.0 ml). The organic layer was washed with water and brine solution which was finally dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 40% ethyl acetate in hexane to get the title compound. Yield=53% (0.15 g, 0.37 mM).
[0111] 1 H NMR (CDCl 3 ): δ 7.46-7.55 (m, 2H), 7.19-7.34 (m, 8H), 5.32-5.33 (m, 1H), 3.59-3.71 (m, 4H), 3.46-3.54 (m, 2H) 2.15-2.17 (m, 1H) 1.54-1.59 (m, 2H), 1.45-1.50 (m, 7H), 1.25-1.37 (m, 2H).
Example 12
Preparation of (3S)-1-[(benzyloxyacetyl)]pyrrolidin-3-yl cyclopentyl (hydroxy)phenyl acetate (Compound No. 12)
[0112] The compound (3S)-pyrrolidin-3-yl cyclopentyl (hydroxy) phenylacetate (0.2 g, 0.69 mM) was dissolved in chloroform (10.0 ml). To the reaction mixture, triethylamine (0.19 ml, 1.38 mM) and dimethyl amino pyridine (DMAP) (0.001 g) were added and cooled to 0-5° C. Benzyloxyacetyl chloride (0.14 ml, 083 mM) was added to it and the reaction mixture was maintained at the same temperature for two hours, then at room temperature overnight. The reaction mixture was diluted with chloroform and the reaction was quenched by adding saturated sodium bicarbonate solution (5.0 ml). The organic layer was washed with water and brine solution, dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 40% ethyl acetate in hexane to get the title compound. Yield=66% (0.2 g, 0.46 mM).
[0113] 1 H NMR (CDCl 3 ): δ 7.53-7.59 (m, 2H), 7.25-7.38 (m, 8H), 5.34 (brm, 1H), 4.52-4.67 (m, 2H), 4.09-4.26 (m, 1H), 3.62-3.84 (m, 4H), 3.49-3.52 (m, 1H), 2.85 (brm, 1H), 1.92-2.20 (m, 2H), 47-1.54 (m, 7H), 1.26-1.34 (m, 2H).
Example 13
Preparation of Benzyl (3S)-3-[2-hydroxy-2-cyclopentyl-2-phenylpropanoyl) oxy]pyrrolidine-1-carboxyate (Compound No. 13)
[0114] The compound (3S)-pyrrolidin-3-yl cyclopentyl (hydroxy) phenylacetate (0.2 g, 0.69 mM) was dissolved in chloroform (10.0 ml). To the reaction mixture, triethylamine (0.19 ml, 1.38 mM) and dimethyl amino pyridine (DMAP) (0.001) were added and cooled to 0-5° C. Benzylchloroformate (0.24 ml, 083 mM) was added to it and maintained the reaction mixture at the same temperature for two hours and then at room temperature overnight. The reaction mixture was diluted with chloroform and the reaction was quenched by adding saturated sodium bicarbonate solution (5.0 ml). The organic layer was washed with water and brine solution, dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 40% ethyl acetate in hexane to get the title compound. Yield=65% (0.19 g, 0.45 mM).
[0115] 1 H NMR (CDCl 3 ): δ 7.57-7.61 (m, 2H), 7.30=7.38 (m, 8H), 5.32 (brm, 1H), 5.10-5.17 (m, 2H), 3.38-3.68 (m, 5H), 2.85-2.90 (brm, 1H), 2.13 (brs, 1H), 1.88-1.90 (m, 1H), 1.21-1.47 (m, 8H).
Example 14
Preparation of (3S)-1-[(4-bromophenyl)]pyrrolidin-3-yl] cyclopentyl (hydroxy)phenyl acetate (Compound No. 14)
[0116] The compound (3S)-pyrrodidin-3-yl cyclopentyl(hydroxy)phenyl acetate (0.2 g, 0.69 mM) was dissolved in chloroform (10.0 ml). To the reaction mixture, triethylamine (0.19 ml, 1.38 mM) and dimethyl amino pyridine DMAP (0.001 g) were added and cooled to 0-5° C. 4-bromo benzenesulfonyl chloride (0.21 g, 083 mM) was added to it and the reaction mixture was maintained at the same temperature for two hours and then at room temperature overnight. The reaction mixture was diluted with chloroform and the reaction was quenched by adding saturated sodium bicarbonate solution (5.0 ml). The organic layer was washed with water and brine solution, dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 40% ethyl acetate in hexane to get the title compound as a gummy solid. Yield=43% (0.15 g, 0.3 mM).
[0117] 1 H NMR (CDCl 3 ): δ 7.73-7.74 (m, 4H), 7.28-7.41 (m, 5H), 5.18-5.28 (brd, 1H), 3.25-3.56 (m, 5H), 2.50-2.75 (m, 1H), 2.08-2.10 (brs, 1H), 1.26-1.65 (m, 9H).
Example 15
Preparation of (3S)-1-benzyl-pyrrolidin-3-yl (2R)-cyclopentyl (hydroxy) phenyl acetate (Compound No. 15)
[0118] The compounds (2R)-hydroxy (3-oxocyclopentyl)-2-hydroxy-2-phenylacetic acid (3.0 g, 13.6 mM), (3R)-1-benzyl-pyrrolidin-3-ol (2.0 g, 11.4 mM) were dissolved in dry tetrahydrofuran (80.0 ml) and triphenylphosphine (3.6 mM). To the reaction mixture, a solution of diisopropyl azadicarboxylate (2.7 ml, 13.6 mM) in dry tetrahydrofuran (20.0 ml) was added dropwise under nitrogen atmosphere at room temperature with constant stirring and the stirring was continued for 20 hours at room temperature. Tetrahydrofuran was evaporated under vacuum and the residue was taken in chloroform and washed with saturated sodium bicarbonate solution, water and brine solution, dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 15% ethyl acetate in hexane to get the title compound. Yield=23% (1.2 g, 3.17 mM).
[0119] 1 H NMR (CDCl 3 ): δ 7.65-7.67 (m, 2H), 7.26-7.36 (m, 8H), 5.16-5.21 (m, 1H), 3.56-3.75 (m, 3H), 2.70-2.81 (m, 4H), 2.50-2.60 (m, 1H), 2.10-2.30 (m, 1H), 1.26-1.90 (m, 9H).
Example 16
Preparation of (3S)-1-[[2-(2,3-dihydro-1-benzofuran-5-yl)ethyl]pyrolidin-3-yl] (2R)-cyclopentyl(hydroxy)phenyl acetate (Compound No. 16)
[0120] The compound (3S)-pyrrolidin-3-yl (2R)-cyclopentyl (hydroxy) phenyl acetate (0.2 g, 0.69 mM) was dissolved in acetonitrile (5.0 ml). To the reaction mixture, 5-(2-bromoethyl)-2,3-dihydro-1-benzofuran (0.173 g, 0.76 mM), potassium carbonate (0.29 g, 2.01 mM) and potassium iodide (0.23 g, 1.38 mM) were added and the reaction mixture was heated under reflux for 8 hours and then cooled to room temperature. Acetonitrile was evaporated under vacuum. The residue was partitioned between ethyl acetate (30.0 ml) and water (30.0 ml). The organic layer was washed with water and brine solution. It was dried over anhydrous Na 2 SO 4 and concentrated. The residue was purified by silica gel column chromatography using 30% ethyl acetate in hexane to get the title compound. Yield=46% (0.14 g, 0.32 mM).
[0121] 1 H NMR (CDCl 3 ): δ 7.66 (D, J=1.5 Hz, 2H), 7.28-7.36 (m, 3H), 7.05 (d, J=8 Hz, 1H), 6.94 (d, J=8 Hz, 1H), 6.71 (d, J=8 Hz, 1H), 5.20-5.23 (m, 1H), 4.52-4.58 (m, 2H), 3.80 (s, 1H), 3.18 (t, J=9 Hz, 2H), 2.70-2.92 (m, 8H), 2.50-2.70 (m, 1H), 2.04-2.15 (m, 1H), 1.25-1.61 (m, 9H).
Example 17
Preparation of (3S)-1-[[2-(1,3-benzodioxol-5-yl) ethyl]pyrrolidin-3-yl] (2R)-cyclopentyl(hydroxy)phenyl acetate (Compound No. 17)
[0122] The compound (3S)-pyrrolidin-3-yl (2R)-cyclopentyl (hydroxy) phenylacetate (0.19 g, 0.66 mM) was dissolved in acetonitrile (5.0 ml). To the reaction mixture, 5-(2-bromoethyl)-1,3-benzodioxole (0.18 g, 0.79 mM), potassium carbonate (0.28 g, 1.97 mM) and potassium iodide (0.22 g, 1.31 mM) were added and the reaction mixture was heated under reflux for 9 hours and then cooled to room temperature. Acetonitrile was evaporated under vacuum. The residue was partitioned between ethyl acetate (30.0 ml) and water (30.0 ml). The organic layer was washed with water and brine solution, dried over anhydrous sodium sulphate and concentrated. The residue was purified by silica gel column chromatography using 30% ethyl acetate in hexane to get the title compound. Yield=43% (0.12 g, 0.27 mM).
[0123] 1 H NMR (CDCl 3 ): δ 7.65 (d, J=7.5 Hz, 2H), 7.28-7.36 (m, 3H), 6.64-6.75 (m, 3H), 5.92 (s, 2H), 5.19-5.24 (m, 1H), 3.79 (s, 1H), 2.63-2.92 (m, 7H), 2.45-2.65 (m, 1H), 2.05-2.30 (m, 1H), 1.23-1.80 (m, 10H).
[0000] Biological Activity
[0000] Radioligand Binding Assays:
[0124] The affinity of test compounds for M 2 and M 3 muscarinic receptor subtypes was determined by [ 3 H]-N-methyl scopolamine binding studies using rat heart and submandibular gland, respectively as described by Moriya et al., ( Life Sci. 1999,64(25): 2351-2358) with minor modifications.
[0125] Membrane preparation: Submandibular glands and heart were isolated and placed in ice cold homogenizing buffer (HEPES 20 mM, 10 mM EDTA, pH 7.4) immediately after sacrifice. The tissues were homogenized in 10 volumes of homogenizing buffer and the homogenate was filtered through two layers of wet gauze and filtrate was centrifuged at 500 g for 10 min. The supernatant was subsequently centrifuged at 40,000 g for 20 min. The pellet thus obtained was resuspended in same volume of assay buffer (HEPES 20 mM, EDTA 5 mM, pH 7.4) and were stored at −70° C. until the time of assay.
[0126] Ligand binding assay: The compounds were dissolved and diluted in DMSO. The membrane homogenates (150-250 μg protein) were incubated in 250 μl of assay buffer (HEPES 20 mM, pH 7.4) at 24-25° C. for 3 hours. Non-specific binding was determined in the presence of 1 μM atropine. The incubation was terminated by vacuum filtration over GF/B fiber filters (Wallac). The filters were then washed with ice-cold 50 mM Tris HCl buffer (pH 7.4). The filter mats were dried and bound radioactivity retained on filters was counted. The IC 50 & Kd were estimated by using the non-linear curve-fitting program using G Pad Prism software. The value of inhibition constant Ki was calculated from competitive binding studies by using Cheng & Prusoff equation ( Biochem Pharmacol, 1973.22: 3099-3108), Ki=IC 50 /(1+L/Kd), where L is the concentration of [ 3 ]NMS used in the particular experiment.
[0000] Functional Experiments Using Isolated Rat Bladder:
[0000] Methodology:
[0127] Animal were euthanized by overdose of urethane and whole bladder was isolated and removed rapidly and placed in ice cold Tyrode buffer with the following composition (mMol/L) sodium chloride 137; KCl 2.7, CaCl 2 1.8, MgCl 2 0.1; NaHCO 3 11.9, NaH 2 PO 4 0.4; Glucose 5.55 and continuously gassed with 95% O 2 and 5% CO 2 .
[0128] The bladder was cut into longitudinal strips (3 mm wide and 5-6 mm long) and mounted in 10 ml organ baths at 30° C., with one end connected to the base of the tissue holder and the other end connected to a polygraph through a force displacement transducer. Each tissue was maintained at a constant basal tension of 2 g and allowed to equilibrate for 1 hour during which the PSS was changed every 15 min. At the end of equilibration period, the stabilization of the tissue contractile response was assessed with 1 μmol/L of carbachol consecutively for 2-3 times. Subsequently, a cumulative concentration response curve to carbachol (10 −9 mol/L to 3×10 −5 mol/L) was obtained. After several washes, once the baseline was achieved, cumulative concentration response curve was obtained in the presence of NCE (NCE added 20 min. prior to the second CRC).
[0129] The contractile results were expressed as % of control E max ED50 values were calculated by fitting a non-linear regression curve (Graph Pad Prism). pKB values were calculated by the formula pKB=−log [(molar concentration of antagonist/(dose ratio-1))]
[0000] where,
[0000] dose ratio=ED50 in the presence of antagonist/ED50 in the absence of antagonist.
[0000] The results of the in-vitro tests are listed in Table II.
[0130] In-Vitro Test
TABLE II Receptor Binding Assay M 2 M 3 Functional Assay PKi pki pK B Compound No. 1 <5 <5 — Compound No. 2 5.75 6.97 — Compound No. 3 6.13 7.17 7.54 Compound No. 4 7.32 8.39 7.36 Compound No. 5 6.93 8.02 8.69 Compound No. 6 6.74 7.87 7.84 Compound No. 7 6.82 7.39 — Compound No. 8 6.58 7.25 — Compound No. 9 <5 6.9 — Compound No. 10 5.33 6.81 — Compound No. 11 <6 <6 — Compound No. 12 6.74 7.34 — Compound No. 13 6.39 6.7 — Compound No. 14 6.77 7.4 — Compound No. 15 6.6 8.0 — Compound No. 16 6.9 8.0 — Compound No. 17 7.4 8.5 — Oxybutynin 8.00 9.46 8.93 Tolterodine 8.16 8.15 8.89
[0131] While the present invention has been described in terms of its specific embodiments, certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the present invention.
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This invention generally relates to the derivatives of 1-substituted-3-pyrroli dines having the structure of Formula (I): The compounds of this invention can function as muscarinic receptor antagonists, and can be used for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors. The invention also relates to a process for the preparation of the compounds of the present invention. pharmaceutical compositions containing the compounds of the present invention and the methods for treating the diseases mediated through muscarinic receptors.
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BACKGROUND
1. Field of Invention
This invention relates to the art of wire working and ties of such required around steel reinforcing bars in concrete structures.
2. Description of Prior Art
The present invention may have many applications. The uses of said invention should not be limited to those specifically set forth in the following disclosure.
Wire ties around steel reinforcing bars have been made by manual means using handheld pliers. This causes great worker fatigue and injuries due to repetitive movement syndrome. There has been a long felt need to mechanize this process and work for the reasons mentioned above and also a lessening of fatigue will result in increased production and hence lower costs in performing the operations of making ties about steel reinforcing bars used in concrete structures. Many prior attempts have been made to design devices to perform the function of making wire ties for said steel bars used as reinforcing in concrete structures, but these prior designs have not been commercially successful due to their heavy weight and many precision parts, which are expensive and slow the machine cycle time and are awkward due to the means of being powered.
Prior art in U.S. Pat. No. 3,211,187 to K. Paule, et.al., Oct. 12, 1965, shows complex heavy mechanical controls. Similarly, the patent issued to James E. Ward, U.S. Pat. No. 3,587,688 Jun. 28, 1971, entails a device which utilizes fluid pressure as a driving force which requires many heavy, slow parts to function. Similar prior art U.S. Pat. No. 4,117,872 to Hans Gott, et.al., of Austria, Oct. 3, 1978, is improved but still requires heavy mechanical linkages and externally rotating parts (jaws) which are dangerous and may injure the operator or catch on an obstruction, interrupting the machine's cycle, compared to the present embodiment of the proposed invention which has no externally exposed parts.
Another prior art reference is U.S. Pat. No. 4,362,192 to Donn B. Furlong, et.al., issued Dec. 7, 1982. In this machine, constant rotation of much of the drive mechanisms consume high quantities of energy. Also, the configuration and small size of the clamping and cutting jaw openings would require precise placement and guidance of the wire. This is difficult to achieve due to the stiff nature of the wire which tends to link and deform--making it impossible to precisely guide through small openings.
Further prior art disclosed is the U.S. Pat. No. 4,354,535 to Robert Y. Powell, et.al., dated Oct. 19, 1982, again utilizing heavy pneumatic drive means and many moving parts which wear and are slow in movement.
Additional prior art reference is Forest M. Sarff, et.al., U.S. Pat. No. 3,880,204 issued Apr. 29, 1975. This device entails many mechanical moving parts.
OBJECTS AND ADVANTAGES
The present embodiment of the invention disclosure provides a lightweight, fast, portable and economical method of attaining the goal of automating the process of making wire ties about steel reinforcing bars used in concrete structures. Great economies of manufacture of this device will result due to the many components which are presently commonly available through catalog suppliers and only a very few components which are custom manufactured. This is due to the unique and previously undiscovered details which are incorporated in the preferred embodiment of the invention. Lightweight, economical integrated circuits and composite plastic materials are used extensively due to the unique construction of the invention which heretofore was not discovered and entails fewer moving parts than any previously disclosed prior art.
Accordingly, several objects and advantages of my invention are: portability due to lightweight construction because many moving parts have been eliminated which were used for control and timing of the sequencing and machine operation. The preferred embodiment of the invention uses light, low cost and dependable electronic integrated circuits, electronic limit switches, electronic solenoids and motors all of which are conventional in construction and readily available through many catalog suppliers presently.
The unique features of the invention provide fast and efficient means for making tight, strong wire ties with a minimum of wire wasted in the process by locating the cutter very close to the tie. Furthermore, it provides adjustable means to further meter amounts of wire fed and further reduce waste. Because of these unique features, the invention will be a dependable, light, low cost and efficient machine which will enable even unskilled workmen to operate, and furthermore, the previously undiscovered details of the present embodiment of the invention yield a tool which is fast, efficient and economically attractive for commercial production. Additionally claimed objects and advantages are a safe, lightweight tool with few and lightweight moving parts.
Readers will find further objects and advantages of the invention from a consideration of the ensuing description and the accompanying drawings:
DRAWING REFERENCE NUMERALS:
12-Left Housing Side Cover
14-Wire Supply Reel
16-Right Jaw Closing Solenoid
17-Left Jaw Closing Solenoid
18-Connector Shaft
20-Thrust Shaft
22-Jaw Clamp and Cutter Head
23-Left Clamping Head
24-Fixed Jaw Boss
26-Fixed Jaw Trust Head
28-Wire Channel Guide Rotation Drive Gear
29-Drive Motor
30-Shaft Mount for 14
32-Drive Motor for Turret Rotation
34-Turrent Gear Drive Shaft
36-Drive Gear for Turret Rotation
38-Turret Gear
40-Commutator Ring
42-Wire Channel Guide
44-Electronic Logic Control Circuitry
46-Right Housing Side cover
48-Slider Solenoid Mounting Bracket
50-Moveable Wire Feed Assembly Slider Solenoid
52-Threaded Adjustable Connecting Link
54-Connecting Flange
56-Screws
58-Connecting Screws
60-(Left) Slider Guide
62-Idler Shaft for Wire Feed Driving Wheel
64-Driven Adjustable Feed Wheel Shaft
66-Wire Feed Driving Wheel
68-Driven Adjustable Feed Wheel
70-Drive Wheel Pressure Adjustment Screw
72-Drive Wheel Pressure Adjustment Thrust Frame
73-Wheel Tension Adjuster Tray
74-(Right) Slider Guide
76-Electric Trigger Mechanism
78-Moveable Wire Feed Mechanism Assembly
80-Trigger Mounting Shaft
82-Jaw Assembly (consists of several components)
84-Turret Realignment Flux Proximity Detector
86-Wire Feed Path (not part of invention)
94-Thrust Rod
96-Fixed Electric Brush
98-Mount (to connect 96 to 46)
104-Electrical Wire Connector
106-Wire Feed Reversible Driving Motor
108-Moveable Wire Guide Fence
110-Mounting Screws for 108
112-Replaceable Hardened Cutter Head
114-Replaceable Knurled Jaw Grips
116-Jaw Mounts
DRAWING FIGURE
FIG. 1 Shows an exploded isometric view of the wire tying device in accordance with the invention.
FIG. 2 Shows a sectional elevation view of the wire tool taken from FIG. 1.
FIG. 3 Shows a front sectional view of the wire tying tool taken from FIG. 2.
FIG. 4 Shows an electrical schematic for the control and timing circuitry of the wire tying tool.
FIG. 5 Shows a sequence flow chart for operation of the various components of the wire tying tool.
FIG. 6 Shows a sectional view of the wire channel guide from FIG. 2.
FIG. 7 Shows an enlarged perspective view of the turret component assembly with the wire path shown.
FIG. 8 Shows a partial elevation sectional view of the moveable wire feed mechanism (assembly) taken from FIG. 3. (Designated as Drawing Reference No. 78.)
FIG. 9 Shows a top view of the assembly of FIG. 8 (Servo not shown for clarity).
FIG. 10 Shows an enlarged elevation of the moveable wire guide fence from FIG. 8.
FIG. 11 Shows a sectional view of the moveable wire guide fence of FIG. 10.
FIG. 12 Shows an enlarge exploded perspective view of the jaw assembly. (Designated as Drawing Reference No. 82.)
DESCRIPTION
FIG. 1 shows the wire tying tool according to the preferred embodiment of the invention. The tool comprises two housing side covers (12 and 46) with an electric trigger mechanism (76) mounted to each half by mechanical means (not shown). Each housing side cover has a projecting flange to which the wire supply reel (14) is connected by shaft mount (30). Connected and mounted to one housing side cover is the electronic logic control circuitry (44). The various electronic and electrical components, as can best be seen schematically in FIG. 4, of the wire tying tool are connected by wire or other suitable means to this component of the invention and are not shown. Rotatably mounted to the left housing side cover at the bottom rear is the wire channel guide (42) which pivots from the idle position to the actuated position as can best be seen from FIG. 2. The gear teeth of (42) are meshed with the gear teeth of the wire channel guide rotation drive gear (28). This is in turn connected to drive motor (29). Mounted midway between 12 and 46 and projecting through the opening in the bottom of these pieces is the turret with gear teeth (38). Mounted atop the turret and annular in shape is the commutator ring (40). (38) is meshedly connected to the drive gear for turret rotation (36) which is rotatably connected to the turret gear drive shaft (34). (34) is connected to the vertically oriented drive motor for turret rotation (32). Mounted atop (38) connected by the jaw mounts (116), and within the annular space of (40) is the fixed jaw thrust head (26). Directly opposed to (26) and paralledly mounted to the bottom portion of (26) is the fixed jaw boss (24). Inside one of the rectangular hollows of (24), the moving jaw clamp and cutter head (22) inserts. (22) is pin connected to thrust rod (94) which connects to the connector shaft (18). (18) is connected by means of a pinned joint to the jaw closing solenoid (16). As can best be seen in FIG. 12, mounted directly adjacent to (16) and parallel to it is the left jaw closing solenoid (17) which connects to the left clamping head (23) by means of thrust shaft (20). (23) passes through the second rectangular void in (24) in a similar fashion to that of (22). Mounted above the turret and below the electronic logic control circuitry (44) is the moveable wire feed mechanism assembly (78) consisting of several components as can best be seen in FIGS. 8 and 9 which shows these components in sectional elevation view and top view. Left slider guide (60) and right slider guide (74) are interconnected by a solid means at each end which will allow separation and which are solidly mounted to (12) and (46) respectively. Idler shaft for wire feed driving wheel (62) and driven adjustable feed wheel shaft (64) mount inside the hollowed grooves of (60) and (74) in a perpendicular orientation to the minimal dimension. Fit around the periphery of (62) and (64) in a rotatable fashion are the flush and intangential contact vertically opposed wire feed driving wheel (66) and the driven adjustable feed wheel (68). Surrounding (66) and (68) and having parallel grooves in a rectangular guide inset between (60) and (74) is the wheel tension adjuster tray (73) to which the drive wheel pressure adjustment thrust frame (72) is threadably attached to (73) by means of the drive wheel pressure adjustment screw (70) at the one end and through which (64) passes through at it's other extreme end. Mounted above and connected by screw means to (72) is connecting flange (54). Passing through a hole in the top of (54) is the threaded adjustable connecting link (52). The one end of (52) then attaches to the moveable wire feed assembly slider solenoid (50). Above (50) is the slider solenoid mounting bracket (48) which attaches (50) to (46) by means of connecting screws (58). Mounted between (74) and (60) and extending below each is the moveable wire guide fence (108) connected by mounting screws (110). Mounted to the side of (74) and shaftably connected to (62) is the wire feed reversible driving motor (106).
Mounted near the top hollowed handle shaped portion of (12) is the electric trigger mechanism (76). The piece (76) is connected to (12) by trigger mounting shaft (80) as can best be seen in FIG. 3. As can best be seen in FIG. 3, the turret realignment flux proximity detector (84) mounts to the left and right housing side covers (12) and (46) respectively and is adjacent to (38). As can best be seen by FIG. 6, the fixed electric brush (96) is supported by mount (98), (96) is in contact with and above (40). Electrical wire connection (104) is connected between (16) and (40). As can best be seen by FIG. 10, the replaceable hardened cutter head (112) is flatly mounted to the top of vertical inside face of (26) on the side facing (22). Mounted at the bottom vertical inside faces of (22) and (26) are the parallel opposed repalceable knurled jaw grips (114).
OPERATION
The wire tying tool for concrete reinforcing steel of FIGS. 1 to 12 performs the function of automatically making wire ties about crossed or lapped steel reinforcing bars. Firstly, the operator positions the tool atop the members to be tied and then initiates the machines cycle by depressing the electric trigger mechanism (76) which pivots about the trigger mounting shaft (80). This action electrically activates drive motor (29) which is connected to wire channel guide rotation drive gear (28) causing rotation which in turn meshably engages the gear teeth of the wire channel guide (42) and causes rotation of this piece in an upward direction as can best be seen in FIG. 2. When the wire channel guide contacts the bottom of (38) rotation stops and wire feeding begins. Wire is stored on the wire supply reel (14) and feed is begun by the electronic logic control circuitry (44) activating the wire feed reversible driving motor (106) which is shaftably connected by the idler shaft for wire feed driving wheel (62). This in turn causes rotation of wire feed driving wheel (66) which sandwiches the wire being fed against the driven adjustable feed wheel (68) causing the wire to be frictionally driven downwards through the wheels. Guidance of the wire is aided by the moveable wire guide fence (108) since it steadies the wire movement and prevents kinking by aligning the wires' path by contact with it vertically. The moveable wire guide fence (108) also helps steer the wire into the top of the wire channel guide (42) and again stays in contact with the wire to prevent kinking until the wire is fed through the wire channel guide (42) and exits out of it at the end opposite the wire channel guide rotation gear and continues in an upwards direction through the opening in the turret gear (38) and continues between the fixed jaw boss (24) and the parallelably opposed fixed jaw thrust head (26). Electrical power is conveyed to the electrical components mounted on (38) by means of commutator ring (40) which is in contact with fixed electric brush (96). (96) is mounted to (46) by mount (98) which supplies support for it. (96) is connected electrically to (44) by electrical wire connector (104). When this occurs (as metered by the electronic logic control circuitry), the wire feed stops. At this point, the left clamping head (23) is moved linearly towards the fixed jaw thrust head (26) by action of the left jaw closing solenoid (17) which linearly applies force along thrust shaft (20) which contacts (23) at it's rear vertical face. When (23) contacts the fed wire, it continues along it's path until clamping pressure forces the wire against the replaceable knurled jaw grip (114). At this point, the fed wire is clamped and cannot move. At this point, the drive motor (29) reverses it's direction of rotation from it's initial directional movement and in turn reverse-rotates (28) and causes (42) to swing back to it's starting position as can be seen in FIG. 2. Now the fed wire must be moved into position so that it may be cut. This is accomplished by activation of moveable wire feed assembly slider solenoid (50) which is attached to right housing side cover (46) by means of attachment screws (58) and mounting bracket (48). Both (46) and left housing side cover (12) provide a continuous frame for attachment of the various machine components as well as serving as a protective housing to guard from dirt and debris damage. The force from (50) is linearly transmitted by means of threaded adjustable connecting link (52) which at it's opposite end is connected to connecting flange (54) which is oriented above and screwably connected to drive wheel pressure adjustment thrust frame (72) by means of screws (56). The linear motion causes (73) to move parallel to and between the left slider guide (60) and the right slider guide (74). (60) and (74) provide support for the driven adjustable feed wheel mounting shaft (64) which is in contact with the slot in (74) and at the opposite end slot in (73). (73) and (74) also provide support for idler shaft (62) which mounts in parallelably opposed holes in (60) and (74). When (73) moves linearly in the slots of (60) and (74), it also transmits linear force to the drive wheel pressure adjustment thrust frame (72) which can best be seen in FIG. 1 which moves (72) linearly over the top of (22) so that the wire feed drive wheel (66) and the driven adjustable feed wheel (68) are moved with (72) (since they are connected by shaft (62) and (64) respectively to (72)) to a position which centers the gap between (66) and (68) directly over the center and above the opening between (22) and (26). Thus since the wire feed path (86) passes between said gap, then the wire will now be between the faces of (26) and (22). Now the slack in the fed wire is removed by reversing the rotation of (106) causing reverse rotation of (66) which forces the wire in an upward direction by means of it being clamped between (66) and (68). The electronic control circuitry (44) then activates the right jaw closing solenoid (16) causing connector shaft (18) to be moved linearly toward (26). Since (18) is connected to thrust rod (94), (94) is in turn moved toward moving jaw clamp and cutter head (22). At the top and bottom of it's back vertical face, (22) connects to (94) so that (22) is forced through the rectangular shaped opening (24) and the triangular shaped cutting surface point of (22) contacts the fed wire at the top forcing it against (112) simultaneously cutting the wire at the bottom knurled front face of (22). The wire is clamped against the inside front face of (114) so that the wire cannot move. The electronic logic control circuitry (44) now deactivates (50) so that the above described motion is reversed and the moveable wire feed mechanism assembly (78) returns to it's starting position. Clamping force can be adjusted between (66) and (68) by means of the drive wheel pressure adjustment screw (70) by reaction against (72) and force transmitted through (73) to (64) pressing (68) harder against (66). The electronic logic control circuitry (44) now activates drive motor for turret rotation (32) causing rotation of turret gear drive shaft (34) which causes the drive gear for turret rotation (36) to turn and with it the jaw assembly (82) is rotated atop turret gear (38) since (36) is meshed with turret gear (38) causing it to rotate which twists the fed wire about the members being tied. When a predetermined load is reached, (16) and (17) are deactivated thus releasing clamping force from both ends of the fed wire. The jaw assembly (82) and turret gear (38) continue to rotate until the long horizontal axis of the jaw assembly is in line and parallel to the vertical plane of the wire channel guide (42) and oriented so that the cycle is ready to begin again. Wire supply reel (14) is mounted about support shaft (30). Jaw mounts (116) supply a means for connecting (26) to (38). The positioning is controlled by the turret realignment flux proximity detector (84). Thus, the reader will see that the wire tying tool for reinforcing steel of the invention provides a highly reliable, lightweight, yet economical device which can be used by any person regardless of their level of skill.
While my above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. For example, the jaw assembly (82) could be inset into the body of turret gear (38), lower than what is shown, to reduce the amount of wire used in each cycle by shortening the distance between the members being tied and the cutter head. Various sized and shaped wire channel guides (42) could be designed to accommodate different sized and shaped objects to be tied. Also, the geometrics and power of the overall machine could be adpated to accommodate various sizes of wire to be used for the tying process. Also, the motive forces could be accomplished by other than electricity. Hydraulics, pneumatics and solar electrical powers could be utilized. The device could also be non-portably base mounted. Also, the grip handles (incorporated into (12) and 46)) length could be increased to afford greater comfort to the operator.
Accordingly, the scope of invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.
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A handheld power tool for making wire ties about elongate members of the type encountered in reinforced concrete construction. The tool is comprised of a body which encompasses the machinery, above electrical logic circuitry to control the component moters, switches, and other components. Midway in the housing the device feeds wire through feed rollers and through a wire guide at the bottom of the housing which directs the wire about the members that are to be tied together. The wire continues to be fed through a circular turet to which are mounted two side-by-side clamping jaws--one which will clamp the "dead" end of the wire while the feed wheels reverse their direction to take slack out of the wire and initially tighten it about the bars. The feed wheel assembly then transiates to a position that aligns the "live" end of the wire being fed between the second (side-by-side) jaw where it is clamped and cut. The turret and attached jaws then rotate (after the feed wheel assembly is moved out of the way), which accomplishes the desired task of making a wire tie about the concrete reinforcing bars. The components then return to their beginning positions and another cycle of operation is ready to begin.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a U.S. national stage of application No. PCT/EP2010/061901 filed 16 Aug. 2010. Priority is claimed on German Application No. 10 2009 040 035.4 filed 3 Sep. 2009, the content of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to data communications and, more particularly, to a transmission method in a wireless data bus network including data transmission cycles, e.g., superframes, comprising a multiplicity of time slots of matching length, wherein each time slot includes a particular associated subscriber on the data bus network exclusively for the purpose of transmitting data.
[0004] 2. Description of the Related Art
[0005] Wireless data bus networks involve the use of various methods for regulating access by the communication subscribers to the time slots which are available during the data transmission cycles.
[0006] A first type involves each subscriber being granted an exclusive access right to a time slot. The time slots that are available in the data transmission cycles are thus each firmly associated with a particular subscriber. These access methods are called time-division multiplex methods or “TDMA Time Division Multiple Access”. Access methods based on this principle advantageously have not only freedom from collisions but also a deterministic cycle time, i.e., there is a maximum latency for the transmission of a message. However, the average latency is designed for the maximum possible data traffic and therefore cannot be reduced even in the event of temporarily reduced data traffic.
[0007] A second type involves the subscribers all being able to access the time slots that are available in the data transmission cycles simultaneously and to attempt to transmit data messages therein. These access methods are called “CSMA Carrier Sense Multiple Access”. In order to avoid collisions, subscribers wishing to access a time slot simultaneously initially listen to a time slot for a short waiting time to ensure that the time slot has not been engaged in the meantime by another subscriber for the purpose of transmitting a data message. If no data transmission by another subscriber can be established at the end of the waiting time, the “listening” subscriber assumes that the time slot is free and engages it by transmitting its own data. The advantage of these methods is that a low load in a wireless communication network involves very short latencies. The disadvantage is that when the load is high the latencies can become large because of possible message repetitions, and it is not possible to determine a maximum latency.
[0008] In the case of wireless data bus networks on a radio basis which are used for industrial communication, the data transmission needs to meet the requirements of determinism and realtime capability. The data transmission thus needs to have concluded early enough for it to be process compatible, i.e., the flow of a technical process is not disturbed thereby. In addition, the maximum cycles times which occur must be able to be calculated and must be as short as possible. Finally, latencies need to be as short as possible, and messages need to be transported via different communication paths with as little delay as possible.
[0009] In order to meet requirements of this kind, use is frequently made of access methods in which a TDMA method is complemented by a CSMA method. This makes it possible to combine the advantages of TDMA methods, preferably the deterministics, and of CSMA methods, preferably the short mean latencies. Such combined access methods produce only little additional communication complexity and can be used advantageously in automation and process engineering, e.g., in “energy self-sufficient sensors”, i.e., in energy-saving sensors, e.g., with a local supply of power by a battery. A combined access method is characterized in that although the time slots which are available in a data transmission cycle have a static stipulation over which subscribers are able to have the respective time slots, i.e., which subscribers are exclusively permitted to transmit data in which time slots, if one of the subscribers does not make use of its right to data transmission in the associated time slot of a data transmission cycle, for example, because there are no data for transmission, then other subscribers are able dynamically to alternately engage this time slot on a competitive basis.
SUMMARY OF THE INVENTION
[0010] It is therefore an object of the invention to provide a method which can be used to dynamically associate a released time slot with other subscribers in this manner safely, i.e., without collisions.
[0011] This and other objects and advantages are achieved in accordance with the invention by implementing a method in a wireless data bus network, i.e., the radio network, which involves a deterministic transmission method. To this end, there is a fixed data transmission cycle comprising a multiplicity of time slots of matching length, also called a superframe. In this case, each subscriber currently registered on the data bus network has at least one firmly associated time slot in the data transmission cycle for the purpose of transmitting data. This fixed time slot can be used exclusively by the associated subscriber to transmit data. Each other subscriber is excluded from using the time slot of the associated subscriber. If data transmission is also requested by another subscriber in the meantime, this other subscriber must wait until the time slot that is associated with the subscriber itself is processed in the current data transmission cycle. Only then is the other subscriber permitted to begin the data transmission, because otherwise sending the data simultaneously with further subscribers would result in collisions. However, such a method entails those time slots that are associated exclusively with all subscribers which currently have no data to transmit remaining unused in each data transmission cycle. Although this allows a purely deterministic behavior by the data bus network, it also results in great latency. The method of the invention is used to extend such a purely deterministic time slot association as follows.
[0012] At the beginning of each time slot, the method of the invention involves an engagement period being started. The subscriber which is exclusively associated with a time slot needs to have made use of the time slot within the engagement period and needs to have begun sending data. Otherwise, this subscriber loses its right to exclusive engagement of the time slot when the engagement period elapses. If instead the engagement period elapses unused without the exclusively associated subscriber having begun sending, this time slot has effectively been released. It is now possible for other subscribers on a data bus network to attempt to engage the time slot and to use the remaining time up to the end of the time slot for an interjected data transmission with a deferred starting time. Particularly advantageously, subscribers which have a request for data transmission lend themselves to this. The method of the invention then involves the released time slot being associated using an engagement method. Examples of this are explained in more detail below.
[0013] An advantage of the method in accordance with the invention is that this retrospective engagement of a released time slot takes account of all subscribers on the data transmission network to the same degree. This also includes the subscriber that was originally exclusively associated with the time slot, and which received a request for data transmission only after the engagement period had elapsed, for example. This subscriber then has the same rights as the other subscribers when an engagement method is applied.
[0014] In accordance with an advantageous further embodiment of the invention, this engagement period begins subsequently to a waiting time after the beginning of the respective time slot. In practice, such a waiting time after the start of a time slot is frequently helpful for ensuring that switching processes in the wireless data bus network have concluded. It is thus advantageous to wait at the beginning of a time slot when the engagement period starts until all subscribers in the data transmission network have had internal process flows, particularly those conditional upon hardware processing times, concluded with certainty. An example which should be cited for these are those process flows which occur within a subscriber when switching between a sending mode and a receiving mode.
[0015] In accordance with further embodiments of the invention, it is possible to apply various engagement methods to associate the active time slot with another subscriber after the engagement period has elapsed, and in this way to allow this subscriber to perform an interjected data transmission with a deferred starting time. In the case of a first possible embodiment for an engagement method, a criterion used for selecting another subscriber is the interval of time between the released active time slot and the time slots that are exclusively associated with subscribers having a request for data transmission, i.e., subscribers wishing to send, in the data transmission cycle. It is particularly advantageous if this particular embodiment involves the released time slot being associated with that other subscriber wishing to send for which the individual exclusively allocated time slot in the data transmission cycle is still furthest away from the released time slot. In a case of this kind of engagement method, preference is thus given to that subscriber for which the longest waiting time until the appearance of the exclusively usable time slot would arise. Thus, the starting time for an interjected data transmission is brought forward for that subscriber for which the longest latency would arise in the event of a normal deterministic flow of the data transmission cycle. By contrast, all other, unselected, subscribers wishing to send experience only relative short waiting times until the exclusively associated time slot is processed, depending on the system. This deterministically results in an exclusive selection of only one of the subscribers wishing to send at all times. In addition, this selection promises maximum possible shortening of the latency on the data bus network.
[0016] In a second possible embodiment for an engagement method, a random method is used for associating one of the subscribers wishing to send with the released time slot. Here, each of the subscribers wishing to send uses a random method to determine a standalone starting time—situated in the released time slot after the engagement period has elapsed and before the end of this time slot—for possible commencement of a data transmission. Before a subscriber wishing to send actually begins the data transmission when the starting time calculated in this manner is reached, however, the wireless data bus network is checked by the subscriber. Here, it is necessary to establish whether the wireless data bus network is still unengaged, i.e., that no other subscriber wishing to send has begun transmitting data in the meantime. If this is the case, then the data transmission is begun and the time slot is engaged by this subscriber. In the presently contemplated embodiment, the released time slot is thus associated with that subscriber wishing to send that that has randomly determined a starting time which is situated closest to the end of the engagement period. When this fastest subscriber has begun the data transmission, no other subscriber wishing to send is then able to commence a data transmission. This is because when these subscribers reach the respectively calculated starting times, the checks on the wireless data bus network reveal that it is engaged and it is no longer possible to commence a data transmission in the active time slot.
[0017] In the presently contemplated embodiment, it is particularly advantageous if each subscriber wishing to send determines a starting time by multiplying a prescribed waiting time by a random number. This also results in starting times situated at different distances from the end of the engagement period, and priority is established among the subscribers wishing to send. While the waiting time, determined from the random number and the waiting time slot, is elapsing before the respective starting time is reached, each subscriber wishing to send also monitors the wireless data transmission network. When the deferred starting time is reached, the data transmission is begun—in this case too—only if the data transmission network is hitherto still unengaged, i.e., that no other subscriber wishing to send has begun a data transmission in the meantime. Only in the rare exceptional case that two subscribers wishing to send encounter the same random number by chance is a collision unavoidable. Based on the range of values for the random numbers and the length of the waiting time slot, the occurrence of such an event can be greatly reduced.
[0018] Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWING
[0019] The invention is explained in more detail with reference to the exemplary embodiments illustrated in the figures which are presented briefly below, in which:
[0020] FIG. 1 shows an exemplary structure of a time slot in a data transmission cycle (“superframe”) in the data transmission method in accordance with the invention;
[0021] FIG. 2 a shows an exemplary time slot from FIG. 1 , where time slot has been used by the exclusively associated subscriber within an engagement period for the purpose of transmitting data;
[0022] FIG. 2 b shows an exemplary time slot from FIG. 2 a with action periods of another subscriber, which is intended to receive the data from the exclusively associated subscriber;
[0023] FIG. 3 a shows an exemplary time slot from FIG. 1 , where the time slot has been used by another subscriber instead of the exclusively associated subscriber after the engagement period has elapsed for the purpose of transmitting data;
[0024] FIG. 3 b shows an exemplary time slot from FIG. 3 a with the action periods of a further subscriber which is intended to receive the data from the other subscriber; and
[0025] FIG. 4 is a flow chart of the method in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] FIG. 1 shows an exemplary structure of a time slot Tx with a fixed length in a data transmission cycle which has a multiplicity of such time slices of equal length. Here, the time slot Tx with the starting time t_a and the ending time t_e has three ranges. The first range between the starting time t_a and a time t_t is a waiting time Tw. It is advantageous to await the elapsing of this waiting time Tw particularly when changing between time slots, in order to allow the hardware, particularly in the subscribers in the wireless data bus network, to switch properly between the sending and receiving states, for example. The subsequent, second range between the times t_t and tw_max is the maximum permissible engagement period Tb in accordance with the invention for the subscriber that has been exclusively allocated the time slot Tx in the superframe for the purpose of data transmission. This subscriber needs to have actually used the time slot, by beginning a data transmission, no later than when the engagement period Tb elapses at the time tw_max. Otherwise, other subscribers wishing to send can attempt to be associated with the time slot in the third range of the time slot Tx, the residual period T_sr_all, for the purpose of transmitting their own data packets. Such a transmission should, where possible, have been concluded within the residual period T_sr_all, i.e., before the time t_e is reached, however.
[0027] FIG. 2 a shows an exemplary time slot Tx from FIG. 1 , where the time slot has been used by the exclusively associated subscriber within the engagement period Tb for the purpose of transmitting data. To this end, this subscriber begins to transmit a data packet 1 of length T_sr_data at the time t_sr_o. In accordance with the invention, this starting time t_sr_o is within the engagement period Tb. In this way, the subscriber takes advantage of its right to exclusively engage the time slot Tx in good time and can terminate the transmission of the data packet 1 properly without disturbance by other subscribers in the data bus network at the time t_se. There then follows a reception period 2 of length T_h in which the subscriber expects the arrival of an acknowledgment message from another subscriber, which is intended to receive the data packet 1 .
[0028] FIG. 2 b shows an exemplary time slot Tx from FIG. 2 a , with the action periods of another subscriber, which is intended to receive the data from the exclusively associated subscriber. This other subscriber is ready to receive when the waiting time Tw elapses at the time t_t, and receives the data packet 1 within the reception period 3 of length T_h. The transmission of the data packet has in turn concluded at the time t_se. There follows a sending period 4 of length T_q in which the other subscriber, which is intended to receive the data packet 1 , returns an acknowledgment message about positive receipt of the data packet 1 to the holder of the time slot Tx.
[0029] FIG. 3 a again shows the exemplary time slot Tx from FIG. 1 . The exclusively associated subscriber has not yet begun to transmit data by the time tw_max. As a result, other subscribers can now be associated with this time slot. Instead of the exclusively associated subscriber, the time slot in FIG. 3 a has therefore been used by another subscriber for the purpose of transmitting data after the engagement period Tb has elapsed. In this regard, it has been assumed in the example in FIG. 3 a that at the time t_sr_csma another subscriber receives a request for transmitting a data packet 6 to a further subscriber in a data bus network, which further subscriber is intended to receive the data packet 6 .
[0030] This subscriber wishing to send does not commence the data transmission immediately, however. On the contrary, it is possible for other subscribers also to have a request for data transmission. In accordance with an advantageous further embodiment of the invention, in order to associate the released time slot Tx, each other subscriber which likewise has a request for data transmission uses a random method to determine a starting time t_start, situated after the engagement period Tb and before the end t_e of the time slot Tx, for a possible data transmission.
[0031] In the example in FIG. 3 a , the subscriber wishing to send has ascertained the starting time t_start via a random method, preferably at the moment t_sr_csma at which a request for data transmission was received. When this starting time is reached, the transmission of the pending data packet 6 of length T_s_data is commenced if the subscriber wishing to send can establish that the wireless data transmission network is not yet engaged at this moment. This case is assumed in FIGS. 3 a and 3 b.
[0032] The subscriber wishing to send thus encounters a sending delay T_d of length T_h which is caused by the randomly determined starting time t_start. This sending delay can also be used as a reception period 5 in which the subscriber wishing to send already monitors the transmission link for engagement by any subscriber in the wireless data bus system.
[0033] In accordance with a further embodiment of the invention, the deferred starting time t_start for a possible data transmission and the resultant sending delay T_d of length T_h can be determined by the subscriber wishing to send by multiplying a prescribed waiting time Tk by a random number k. The result is that the transmission of the data packet 6 of length T_s_data can be commenced by the subscriber wishing to send at the starting time t_start only if the relevant calculations of other subscribers which likewise have requests for data transmission result in a later starting time on account of a greater random number or a later arrival of a request for data transmission.
[0034] The conclusion of the transmission of the data packet 6 at a time t_se, as assumed in FIG. 3 a , is again followed by a reception period 7 of length T_q in which the sending subscriber expects the arrival of an acknowledgment message from the further subscriber which is intended to receive the data packet 6 .
[0035] FIG. 3 b shows the exemplary time slot Tx from FIG. 3 a with the action periods of this further subscriber. In this case, there is again a reception period 8 of length T_h in which the further subscriber which is intended to receive the data packet 8 is ready to receive and listens to the data transmission link for the transmission of data packets which are intended for it. This reception period 8 ends at the time t_se at the same time as the transmission of the data packet 8 concludes. There follows a sending period 9 of length T_q in which the further subscriber which is intended to receive the data packet 6 returns an acknowledgment message about positive receipt to the other subscriber. As can be seen from the examples in FIGS. 1 to 3 b , all of the operations described above should, where possible, have been concluded before the ending time t_e of the time slot Tx is reached.
[0036] FIG. 4 is a flow chart of a transmission method in a wireless data bus network having data transmission cycles comprising a multiplicity of time slots of matching length, each time slot of the multiplicity of time slots is respectively associated with a particular associated subscriber on the wireless data bus network exclusively for transmitting data. The method comprises starting an engagement period with the one time slot of the time slots, as indicated in step 410 . Here, the one time slot is engageable exclusively by the associated subscriber of the one time slot to transmit data up to expiration of the engagement period.
[0037] The one time slot, which has been released after the engagement period has elapsed, is associated exclusively with another subscriber on the data bus network based on an engagement method for transmitting the data, as indicated in step 420 .
[0038] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
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A transmission method in a wireless data bus network, wherein the method comprises data transmission cycles made of a plurality of time slots of matching length. Each time slot is thereby associated with a particular client on the data bus network exclusively for transmitting data. In accordance with the invention, an allocation duration is started for each time slot, wherein the time slot is utilizable exclusively by the associated client for transmitting data until the duration expires. Alternatively, the time slot that has become available after the allocation duration has expired can be exclusively associated with a different client on the data bus network in accordance with an allocation method for transmitting data.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to use of matrix acidizing in subterranean hydrocarbon formations. In particular aspects, the invention relates to techniques for helping to evaluate the effectiveness of matrix acidizing.
[0003] 2. Description of the Related Art
[0004] Matrix acidizing is a stimulation process wherein acid is injected into a wellbore to penetrate rock pores. Matrix acidizing is a method applied for removing formation damage from pore plugging caused by mineral deposition. The acids, usually inorganic acids, such as fluoridic (HF) and or cloridic (HCl) acids, are pumped into the formation at or below the formation fracturing pressure in order to dissolve the mineral particles by chemical reactions. The acid creates high-permeability, high productivity flow channels called wormholes and bypasses the near-wellbore damage. The operation time depends on such parameters as the length of the wellbore, the rock type, the severity of the damage, acid pumping rate, downhole conditions and other factors.
[0005] Matrix acidizing is also useful for stimulating both sandstone and carbonate reservoirs. Matrix acidizing efficiency in removing the formation damage is strongly dependent on the temperature at which the acidizing occurs and weakly dependent upon the corresponding pressure. The acid temperature in the formation depends on the convective heat transfer as the acid flows through the formation and on the reaction heat transfer due to the acid-mineral reaction.
[0006] Convective heat transfer is the main mechanism for temperature change during acid flow through wormholes. The acid temperature in the wormholes may vary by as much as 10-20° C. (18-36° F.), depending on the initial temperature difference between wellbore and the formation. The acid temperature at the end of the wormholes, about 1-10 m (3.3-33 feet) from the wellbore, may increase by 1°-5° C. (1.8°-8° F.) above the formation temperature at those locations, depending on the injected acid volume.
[0007] Along a wormhole, the temperature changes over time as illustrated by FIG. 4 . Initially, the temperature near the wellbore is the acid temperature inside the well (T w at t=0). The rest of the wormhole, which may be partially or totally undeveloped, is assumed to be at the formation or reservoir temperature (T r at t=0), which is greater than the wellbore temperature. As time progresses and acid is injected through the wormhole, at small radial distances near the wellbore (up to about 1 m (3.3 feet)), the acid temperature decreases from T r to T w with time at a rate depending upon the temperature drop of the fluid flowing from the wellbore. In other words, in the near well region, the temperature behavior depends only on the convection heat transfer due to the acid flow through the wormhole.
[0008] At distances further away than about 1 meter (3.3 feet) and at the advancing acid front region, the acid temperature increases from the well temperature to the formation temperature. This temperature increase is still due mainly to convection heat transfer. However, in the transition between the two temperature levels, the reaction heat transfer between the acid and minerals changes the temperature behavior by smoothing out the temperature change on one side closer to the well and by uplifting the formation temperature by about 1°-5° C. (1.8°-8° F.) on the other side, as FIG. 4 illustrates. The acid temperature changes in both regions (near well and near the acid front). It increases with time and distance due to two mechanisms. First, it depends on the time needed by the acid and minerals to react completely. Second, it depends on the contact area between acid and minerals which increases rapidly with distance. After the acid injection is stopped, the acid-mineral reactions may still continue for some time. However, these reactions take place further away from the well, where the acid front is located. Even the local temperature at the acid front may still increase after the acid injection is stopped. This temperature increase is small and cannot be recorded in the near-well region, so it can be ignored in all additional calculations. At the time when the acid injection is stopped, the temperature along the wormhole is decreasing from almost formation temperature at the wormhole end away from the well (T r at t=t s ) to the well temperature (T w at t=t s ) near the well. As time progresses, the temperature wave moves toward the well at a speed depending upon the wormhole properties (geometry, length, thermal conductivity) and formation properties (porosity, permeability, thermal conductivity, etc.). Eventually, without acid flow, the well temperature (T w ) increases until it reaches the formation temperature (T r ) at time t=t f . Thus, the total time in which the well temperature varies is t f . If the acid injection is started and stopped at times t=0 and t=t s , respectively, between 0 and t s , the well temperature decreases from T w at t=0 to T w at t=t s . This is illustrated by FIG. 5 . Between t s and t f , the well temperature increases from T w at t=t s to T w at t=t f . The time in which the matrix acidizing performance can be evaluated is thus between 0 and t f or between t s and t f , depending on the evaluation technique. In addition to temperature, when the acid flow between the well (annulus) and the formation through wormholes, the local pressure drops due to the change in flow area (such as from the annulus area to the wormhole area). The pressure drop may not be relevant if there is no acid flow. Also, it is worth noting that the temperature and pressure may vary meaningfully only around wormholes (i.e., where there is radial acid flow between the well and the formation).
[0009] Methods for monitoring and evaluating matrix acid stimulations have long been investigated. Recently, distributed temperature sensing (“DTS”) technology has emerged as a tool for real-time data acquisition and interpretation for evaluating matrix acidizing performance. Although the main advantages of this technique (i.e., real time temperature data acquisition along the entire well and great sensitivity) are impressive, there are several major disadvantages as well. First, the DTS fiber is placed inside the coiled tubing string. Recording temperature data with a reasonable resolution assumes that the fiber has to stay immobile for the entire time needed for data acquisition. Second, as the DTS fiber is a multi-point temperature sensor (i.e., the fiber can record temperature data along the well at multiple locations), there is a significant amount of temperature data transmitted to the surface and being processed for all times and multiple positions along the well. Several solutions have been proposed in literature trying to circumvent these disadvantages. However, these proposed solutions are expensive and not reliable.
SUMMARY OF THE INVENTION
[0010] The present invention provides devices and methods that are useful for helping to evaluate the effectiveness of a matrix acidizing treatment. The present invention provides an alternative to DTS technology for matrix acidizing performance evaluation. In a described embodiment, an array of sensors is located at or near the end of the tool string. The sensors are capable of detecting an operational parameter associated with matrix acidizing. In preferred embodiments, the matrix acidizing operational parameters are temperature, pressure, flow rate, flow direction, gamma ray, etc., or any combination of the above. These sensors are disposed upon the outer radial surface of a matrix acidizing bottom hole assembly anywhere along the tool. The sensors are operably interconnected with surface-based signal processing equipment.
[0011] The sensor array is separated into a first set of one or more sensors and a second set of one or more sensors. Each of the sets of sensors is capable of detecting a matrix acidizing operational parameter at a particular location within the wellbore at different times. Therefore, moving the bottom hole assembly past a particular location at a particular speed will permit the first and second sets of sensors to detect the operational parameter at the same location at two different times. If desired, more than two sets of sensors can be used, which will permit the operational parameter(s) to be measured at a single location at multiple times.
[0012] In operation, the tool string and bottom hole assembly are disposed into the wellbore until the sensors are disposed proximate a formation to be acidized. In currently preferred embodiments, the bottom hole assembly is disposed initially located proximate the lower end of the formation or portion of the formation to be acidized. During acidizing, the sensors detect parameters such as temperature, pressure, etc. related to the acidizing operation in a static location and provide these readings to the processing equipment. If desired, the bottom hole assembly and sensors may be relocated within the formation interval during acidizing to perform acidizing in different parts of the formation. This permits the sensors to provided temperature and/or pressure data from different portions of the formation interval.
[0013] After acidizing is completed, the tool string and bottom hole assembly are removed from the wellbore. During removal from the wellbore, the sensors will continue to provide temperature and/or pressure readings to the processing equipment. In a preferred embodiment, the tool string and bottom hole assembly are removed from the wellbore at a predetermined rate of speed so that the first set of sensors will be adjacent a desired location within the wellbore at a first time and the second set of sensors is adjacent the same location at a second time. The desired operational parameter is first detected by the first set of sensors at the first time and then detected by the second set of sensors at the second time, thereby providing detections of the operational parameters at a single point at different times. The matrix acidizing monitoring system of the present invention can be used to provide multiple measurements of operational parameters at multiple points within the formation.
[0014] Processing equipment, preferably surface-based, will interpret the data provided. For example, the temperature detected at a particular location along the formation interval is compared at a first time and a second time to determine whether temperature at the location is increasing, decreasing or unchanged at the location. Changes in pressure at the location can be similarly determined. If pressure/temperature changes are detected at multiple points along the formation interval, the changes along the formation interval can be modeled to help determine the effectiveness of the matrix acidizing operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, wherein like reference numerals designate like or similar elements throughout the several figures of the drawings and wherein:
[0016] FIG. 1 is a side, cross-sectional view of an exemplary wellbore having a tool string therein for conducting matrix acidizing stimulation and monitoring in accordance with the present invention.
[0017] FIG. 2 is an enlarged side, cross-sectional view of an exemplary bottom hole assembly which incorporates a plurality of sensors in accordance with the present invention.
[0018] FIG. 3 is an axial cross-section taken along lines 3 - 3 in FIG. 2 .
[0019] FIG. 4 is a chart illustrating exemplary temperature changes vs. radial distance from a wellbore during acid injection.
[0020] FIG. 5 is a chart illustrating exemplary temperature changes vs. radial distance from a wellbore during acid injection.
[0021] FIG. 6 is a schematic cross-sectional drawing depicting the bottom hole assembly located proximate a location within a formation wherein it is desired to detect matrix acidizing operational parameters at a first time.
[0022] FIG. 7 is a schematic cross-sectional drawing depicting the bottom hole assembly located proximate a location within a formation wherein it is desired to detect matrix acidizing operational parameters at a subsequent second time.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] FIG. 1 illustrates an exemplary matrix acidizing operation being conducted within a wellbore and which incorporates a matrix acidizing monitoring system in accordance with the present invention. Wellbore 10 has been drilled from the surface 12 down through the earth 14 to a hydrocarbon-bearing formation 16 within which it is desired to conduct matrix acidizing. The formation 16 has a vertical formation interval 17 . A tool string 18 has been run into the wellbore 10 from the surface 12 and carries a bottom hole assembly 20 in the form of a matrix acidizing tool. The bottom hole assembly 20 tool is preferably a metal cylinder having temperature and pressure sensors on its outer surface and connected for signal transmission to the surface, as will be described. In a currently preferred embodiment, the tool string 18 is made up of coiled tubing, of a type known in the art, which can be injected into the wellbore 10 . An annulus 22 is formed radially between the tool string 18 /bottom hole assembly 20 and the inner wall of the wellbore 10 . It is noted that, while FIG. 1 depicts a vertical wellbore 10 , this is exemplary only. In fact, the systems and methods of the present invention are applicable to wellbore that are deviated, inclined or even horizontal.
[0024] In operation, acid is pumped down the tool string 18 and is injected under pressure through the matrix acidizing bottom hole assembly 20 into the formation 16 . The injected acid will enter wormholes 24 .
[0025] FIGS. 2 and 3 illustrate an exemplary bottom hole assembly 20 in greater detail. The exemplary bottom hole assembly 20 includes a generally cylindrical tool body 26 which defines a central axial passage 28 along its length. A nozzle 30 is formed on the distal end of the tool body 26 to allow acid injected down the tool string 18 to enter the formation 16 . It should be noted that the figures depict a simplified tool having only a single nozzle 30 . In practice, the bottom hole assembly 20 might have multiple nozzles or openings that allow acid to be dispersed in multiple locations and in multiple directions.
[0026] Radial passages 32 are drilled through the tool body 26 from the central axial passage 28 to the radial exterior of the tool body 26 . A sensor array 33 is provided proximate the lower end of the tool string 18 and preferably upon the tool body 26 of the bottom hole assembly 20 . The sensor array 33 includes multiple sensors 34 which are divided into two sets of sensors 34 a , 34 b . The first set of sensors 34 a is axially separated from the second set of sensors 34 b along the length of the tool body 26 by a length (“x”) (see FIG. 2 ). Each sensor 34 is preferably located at the radially outermost portion of each passage 32 . In particularly preferred embodiments, the sensors 34 are transducers that are capable of detecting temperature and generating a signal indicative of the detected temperature. In alternative embodiments, one or more of the sensors 34 are capable of detecting pressure. It is currently preferred that sensors 34 be spaced angularly about the circumference of the tool body 22 in order to obtain sensed parameters from multiple radial directions around the tool body 22 . In the depicted embodiment, the sensors 34 are located approximately 90 degrees apart from one another about the circumference of the tool body 22 In the depicted embodiment, there are eight sensors 34 . However, there may be more or fewer than eight, as desired.
[0027] Electrical cables 36 extend from the sensors 34 to a conduit 38 that is disposed within the central passage 40 of the tool string 18 . In a particularly preferred embodiment, the conduit 38 comprises a conductor known in the industry as tubewire, which can be disposed within the coiled tubing to provide a Telecoil conductive system for data/power. The term “tubewire”, as used herein, refers to a tube which may or may not encapsulate a conductor or other communication means, such as, for example, the tubewire manufactured by Canada Tech Corporation of Calgary, Canada. In the alternative, the tubewire may encapsulate one or more fiber optic cables which are used to conduct signals generated by sensors 34 that are in the form of fiber optic sensors. The tubewire may consist of multiple tubes and may be concentric or may be coated on the outside with plastic or rubber.
[0028] The conduit 38 extends to surface-based signal processing equipment at the surface 12 . FIG. 1 illustrates exemplary surface-based equipment to which the conduit 38 might be routed. The conduit 38 is operably interconnected with a signal processor 40 of known type that can analyze and in some cases, record and/or display representations of the sensed temperature and/or pressure parameters. Suitable signal processing software, of a type known in the art can be used to process, record and/or display signals received from the sensors 34 . In the instance where the conduit 38 encases optic fibers rather than electrical conductors, the surface-based signal processor 40 includes a fiber optic signal processor. A typical fiber optic signal processor would include an optical time-domain reflectometer (OTDR) which is capable of transmitting optical pulses into the fibers and analyzing the light that is returned, reflected or scattered therein. Changes in an index of refraction in the optic fiber can define scatter or reflection points. The signal processor 40 can include signal processing software for generating a signal or data representative of the measured conditions.
[0029] In conjunction with the processing equipment 40 , the first set of sensors 34 a is operable to detect at least one matrix acidizing operational parameter at a first time while the second set of sensors 34 b is operable to detect the same at least one matrix acidizing operational parameter at a second time that is after the first time. The difference between the first and second time is based upon the rate of movement of the sensor array 33 within the formation 16 relative to a particular point of interest. FIGS. 6 and 7 illustrates a bottom hole assembly 20 being moved within the wellbore 10 past a point 50 within the formation 16 at which it is desired to detect at least one matrix acidizing operational parameter. In FIG. 6 , the first set of sensors 34 a is located proximate the point 50 . In this position, the sensors 34 a detect a matrix acidizing operational parameter at the point 50 . Thereafter, the tool string 18 is pulled upwardly in the direction of arrow 52 until the bottom hole assembly 20 is in the position shown in FIG. 7 . FIG. 7 shows the second set of sensors 34 b located proximate the point 50 . In this position, the second set of sensors 34 b will detect the same matrix acidizing operational parameter(s) as the first set of sensors 34 a . The first set of sensors 34 a detects the parameter(s) at a first time (t1) while the second set of sensors 34 b detect the parameter(s) at a second time (t2). The rate of movement of the tool string 18 and bottom hole assembly 20 in direction 52 should be coordinated with the timing of detection of the operational parameter(s) by the two sets of sensors 34 a , 34 b . This coordination can be conducted, for example, by the processing equipment 40 is such equipment 40 is provided with control over the rate of movement. The processing equipment 40 will compare the operational parameters(s) detected by the first set of sensors 34 a to the operational parameters(s) detected by the second set of sensors 34 b . Thus, it can be determined whether the operational parameter is increasing, decreasing or neither. This manner of measuring operational parameters can be repeated for multiple points or locations along the formation interval 17 . Additionally, more than two sets of sensors might be employed to provide further detail about the measured operational parameter.
[0030] According to an exemplary method of operation, the tool string 18 and bottom hole assembly 20 are disposed into the wellbore 10 and advanced until the bottom hole assembly 20 is proximate the formation 16 into which it is desired to perform matrix acidizing. If desired, packers (not shown) may be set within the annulus 22 in order to isolate the zone into which acid will be released. Thereafter, acid is pumped down the tool string 18 which will then flow through the nozzle 30 of the bottom hole assembly 20 and into the wormholes 24 of the formation 16 . During acidizing, temperature and/or pressure is detected by the sensors 34 and provided to the processing equipment 40 at surface 12 . During acidizing, the bottom hole assembly 20 might be moved from one location to another within the formation interval 17 . Therefore, the sensors 34 will provide temperature and/or pressure readings from different locations within the formation 16 .
[0031] After the acid injection is stopped at time (t s ), the work string 18 is pulled out of the hole at a constant speed that can be calculated depending on the time difference (t f −t s ) and the length of the stimulated zone along the well. Thus, the time t f may be the time that the matrix acidizing bottom hole assembly 20 has traveled the entire well interval of interest. The number of sensors 34 will be dependent on the accuracy of the data acquisition. For instance, a single temperature sensor may not be sufficient for temperature drop data interpretation, as any temperature difference recorded might be due to either axial flow (flow inside the annulus 22 ) or radial flow (flow between the wellbore 10 and a wormhole 24 ). However, multiple sensors 34 could accurately identify of a recorded temperature variation is due to axial flow or radial flow. At least two temperature sensors 34 should be installed sufficiently far away from each other such that they capture temperature differences due to radial acid flow. In particular embodiments, the minimum distance between two temperature sensors 34 is greater than the radial diameter of the wormholes. Thus, it is preferred that the sensors 34 are spaced apart from each other on the tool body 22 by a distance that is greater than the diameter of the wormholes 24 . Theoretical calculations show that the minimum distance between two temperature sensors 34 should be between 4 and 20 meters (13-66 feet), depending upon the reservoir properties (porosity, permeability, wormhole size and shape, geothermal gradient, thermal conductivity, etc.) and well details (shape, dimensions, completion type, etc.). The method could be refined by adding temperature sensors between the two end sensors. Adding more temperature sensors in between increases the accuracy of temperature variation measurement. In addition to the temperature sensors, other sensor types could be used. For instance, pressure sensors could also be installed. Both temperature and pressure measurements are useful in accurately evaluating the matrix acidizing performance when they are coupled with a mathematical model that solves the classical energy flow equation inside the well:
[0000]
∂
∂
t
[
ρ
(
u
+
1
2
v
2
)
]
+
∂
∂
z
[
ρ
v
(
h
+
1
2
v
2
)
]
=
Q
[0000] where ρ is acid density, t and z are time and the curvilinear coordinated along the well path, v is acid velocity, u=c p (T−T ref ) and h=u+p/ρ are the specific internal energy and enthalpy, respectively, c p is the specific heat defined at reference temperature T ref , and T and p are acid temperature and pressure. Note also that Q is the term that includes all other heat exchange effects, such as heat loss due to acid flowing into/from formation.
[0032] The inventors have found that using an array of single-point temperature and pressure sensors at the end of the tool string 18 and pulling them out of the wellbore 10 at a pre-calculated speed has major advantages over DTS technology. First, the acquired data volume is much smaller. This makes the data interpretation process faster and less prone to errors. Second, as the tool string 18 and single point sensors 34 are pulled out of the wellbore 10 after the acid injection has been stopped (at time t=t s ), the operator brings the tool string 18 back to the surface 12 in a shorter time. A DTS fiber and coiled tubing must stay immobile until all data is recorded (usually until time t f ) and then pulled out of the wellbore. Systems and method in accordance with the present invention permit the use of robust, durable conduits, such as tubewire/Telecoil technology. These advantages translate to lower operational costs for the matrix acidizing performance evaluation process when an array of single point sensors 34 at the end of the tool string 18 is used. After real-time downhole temperature and pressure data is acquired and interpreted, the acidizing performance can be visualized by knowing how much acid was injected where. This information is useful for understanding how the formation 16 was treated and if more acidizing is necessary to obtain expected acidizing performance.
[0033] Those of skill in the art will recognize that numerous modifications and changes may be made to the exemplary designs and embodiments described herein and that the invention is limited only by the claims that follow and any equivalents thereof.
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A matrix acidizing monitoring system wherein a sensor array is operably associated with a matrix acidizing bottom hole assembly and contains first and second sets of sensors that detect a matrix acidizing operational parameter at different times at one or more particular locations along the wellbore. This allows the effectiveness of the acidizing to be modeled.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is related to, and claims the benefit of, a foreign priority application filed in Taiwan as Application No. 95144737 on Dec. 1, 2006. The related application is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to backlight modules and liquid crystal display (LCD) devices using backlight modules, and more particularly to a backlight module that can be assembled conveniently.
GENERAL BACKGROUND
Liquid crystal display devices are commonly used as display devices for compact electronic apparatuses, because they not only are very thin but also provide good quality images with little power consumption.
FIG. 9 shows an exploded, isometric view of a typical LCD device 1 . The LCD device 1 includes a bezel 10 , a liquid crystal panel 20 , and a backlight module 40 disposed adjacent to the liquid crystal panel 20 .
The bezel 10 includes a generally rectangular top plate 102 , and four first side walls 104 extending downward from four edges of the top plate 102 . The top plate 102 defines an essentially rectangular display region 107 thereof. Each first side wall 104 defines two first notches 106 therein.
The backlight module 40 includes a brightness enhancement film (BEF) 422 , a diffusion film 421 , a light guide plate (LGP) 430 , an illuminator 440 , a reflection film 460 , a frame 450 , and a bottom tray 470 . The frame 450 , the BEF 422 , the diffusion film 460 , the LGP 430 , and the reflection film 460 are arranged in that order from top to bottom.
The LGP 430 includes a top light incident surface 433 , a light emitting surface 431 adjoining the light incident surface 433 , and a bottom surface 432 adjoining the light incident surface 433 . The illuminator 440 is positioned opposite the light incident surface 433 .
The frame 450 includes four second side walls 452 arranged end to end, and a supporting board 454 . Each second side wall 452 includes two first protrusions 456 and two second protrusions 457 integrally extending perpendicularly outwardly from an outer surface (not labeled) thereof. The supporting board 454 has a frame shape, and integrally extends perpendicularly inward from inner surfaces (not labeled) of the second side walls 452 . The frame 450 therefore defines an upper space for accommodating the liquid crystal panel 20 , and a lower space for accommodating the BEF 422 , the diffusion film 421 , the LGP 430 and the reflection film 460 . The first protrusions 456 correspond in position to the first notches 106 .
The bottom tray 470 includes a bottom wall 472 and eight side plates 474 . The side plates 474 extend perpendicularly upward from four sides of the bottom wall 472 . Two side plates 474 are located at each of four corners of the bottom tray 470 , respectively. Each side plate 474 defines a second notch 476 , corresponding to one of the second protrusions 457 of a respective second side wall 452 of the frame 450 .
When the LCD device 1 is assembled, the BEF 422 , the diffusion film 421 , the LGP 430 , and the reflection film 460 are received in the lower space. The second protrusions 457 of the second side walls 452 of the frame 450 are engagingly received in the second notches 476 of the bottom tray 470 . Thereby, the frame 450 and the bottom tray 470 are locked together. The liquid crystal panel 20 is received in the upper space. The first protrusions 456 are engagingly received in the first notches 106 , and the frame 450 and the bezel 10 are thereby locked together.
When the LCD device 1 is assembled, this is typically performed manually by a human operator. The bottom tray 470 and the frame 450 are generally locked together by force applied in four different directions corresponding to the four second side walls 452 . The bezel 10 and the frame 450 are generally locked together by force applied in four different directions corresponding to the four second side walls 452 . Thus assembly or disassembly of the LCD device 1 is somewhat complicated, problematic, and time-consuming. In addition, a size of each first protrusion 456 is usually slightly less than a size of each corresponding first notch 106 , in order to facilitate assembly. However, this may result in loose engagement of the first protrusions 456 in the first notches 106 . Similarly, a size of each second protrusion 457 is usually slightly less than a size of each corresponding second notch 476 , in order to facilitate assembly. However, this may result in loose engagement of the second protrusions 457 in the second notches 476 .
What is needed, therefore, is a backlight module and a liquid crystal display device using the backlight module that can overcome the above-described deficiencies.
SUMMARY
In one embodiment, a backlight module includes a frame and a bottom plate. One of the frame and the bottom plate includes a plurality of elastically deformable buckling structures, and the other of the frame and the bottom plate includes a plurality of protrusions corresponding to the buckling structures. When the bottom plate is attached to the frame, the bottom plate and the frame are pressed together along a first axis, and the buckling structures elastically deform and then elastically rebound such that the buckling structures are engaged with the protrusions and the bottom plate is fixed to the frame.
In another embodiment, a liquid crystal display device includes a liquid crystal panel and a backlight module. The backlight module includes a frame and a bottom plate. One of the frame and the bottom plate includes a plurality of elastically deformable buckling structures, and the other of the frame and the bottom plate includes a plurality of protrusions corresponding to the buckling structures. When the bottom plate is attached to the frame, the bottom plate and the frame are pressed together along a first axis, and the buckling structures elastically deform and then elastically rebound such that the buckling structures are engaged with the protrusions and the bottom plate is fixed to the frame.
Other novel features and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, all the views are schematic.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded, isometric view of an LCD device according to an exemplary embodiment of the present invention, the LCD device including a bezel, a frame and a bottom plate.
FIG. 2 is an enlarged view of a circled portion II of FIG. 1 .
FIG. 3 is a cross-sectional view of part of the frame taken along line III-III of FIG. 1 .
FIG. 4 is an enlarged view of a circled portion IV of FIG. 1 .
FIG. 5 is a cross-sectional view of part of the bezel taken along line V-V of FIG. 1 .
FIG. 6 is an enlarged view of a circled portion VI of FIG. 1 .
FIG. 7 is a cross-sectional view of part of the bottom plate taken along line VII-VII of FIG. 1 .
FIG. 8 is similar to FIG. 3 , but also showing part of the bezel engaged with the frame, and part of the bottom plate engaged with the frame.
FIG. 9 is an exploded, isometric view of a conventional LCD device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will now be made to the drawings to describe preferred and exemplary embodiments in detail.
Referring to FIG. 1 , an exploded, isometric view of an LCD device according to an exemplary embodiment of the present invention is shown. The LCD device 2 includes a bezel 200 , a liquid crystal panel 210 , and a backlight module 300 , arranged in that order from top to bottom.
The backlight module 300 includes a BEF 322 , a diffusion film 321 , an LGP 330 , an illuminator (not labeled), a reflector 360 , a frame 350 , and a bottom plate 370 . The BEF 322 , the diffusion film 321 , the LGP 330 , the reflector 360 and the bottom plate 370 are arranged in that order from top to bottom.
The LGP 330 includes a top light incident surface 333 , a light emitting surface 331 adjoining the light incident surface 333 , and a bottom surface 332 adjoining the light incident surface 333 . The illuminator is positioned opposite the light incident surface 333 . The reflector 360 is positioned adjacent to the bottom surface 332 .
The frame 350 includes four side walls 352 arranged end to end, and a supporting board 354 . The supporting board 354 has a frame shape, and integrally extends perpendicularly inward from inner surfaces (not labeled) of the side walls 352 . The supporting board 354 defines an opening for allowing light rays to pass therethrough.
Referring also to FIG. 2 and FIG. 3 , each of a pair of two opposite short side walls 352 includes an upside 355 and an underside 356 . The short side walls 352 each define a plurality of first notches 357 . The notches 357 are respectively located at the underside 356 and the upside 355 of each side wall 352 . Each notch 357 at the upside 355 is directly above a corresponding notch 357 at the underside 356 . The short side walls 352 each also include a plurality of buckling structures 358 , which are located in the notches 357 respectively. The buckling structures 358 at the upsides 355 of the side walls 352 are essentially coplanar with the upsides 355 . The buckling structures 358 at the undersides 356 of the side walls 352 are essentially coplanar with the undersides 356 . Each of the buckling structures 358 includes a cap portion 3582 and a body portion 3584 . The body portion 3584 extends vertically from a main body of the short side wall 352 at a bottom of the notch 357 . The cap portion 3582 extends perpendicularly outwardly from a distal end of the body portion 3584 . The body portion 3584 and the cap portion 3582 cooperatively define a hole 3586 therein. The buckling structure 358 therefore has a general shape of a hollow mushroom. The buckling structure 358 is elastically deformable. A height of the buckling structure 358 is generally equal to a depth of the notch 357 . A depth of the hole 3586 is slightly less than the depth of the notch 357 . An outer diameter of the cap portion 3582 is greater than an outer diameter of the body portion 3584 . The buckling structures 358 can be made of plastic. In one embodiment, the buckling structures 358 and the frame 350 are made of the same plastic material. In another embodiment, the buckling structures 358 are made of suitable elastic material that is more elastically deformable than plastic.
Referring also to FIG. 4 and FIG. 5 , the bezel 200 includes a generally rectangular top plate 202 . The top plate 202 defines an opening (not labeled) that serves as a display region. The top plate 202 includes a plurality of depressed collars 204 , thus defining a plurality of first hollows (not labeled) in the depressed collars 204 . The first hollows are generally disc-shaped. Each of the depressed collars 204 defines a first through hole 206 therein. The first through holes 206 of the depressed collars 204 correspond to the buckling structures 358 located at the upsides 355 of the short side walls 352 . The depressed collars 204 are essentially coplanar with one another. A diameter of each first through hole 206 is less than a diameter of the first hollow. A diameter of the first hollow is substantially equal to the outer diameter of the cap portion 3582 of the corresponding buckling structure 358 .
Referring also to FIG. 6 and FIG. 7 , the bottom plate 370 includes a generally rectangular main body 372 . The main body 372 is substantially planar. The main body 372 includes a plurality of upraised collars 374 , thus defining a plurality of second hollows in the upraised collars 374 . The second hollows are generally disc-shaped. Each upraised collar 374 has a structure similar to each depressed collar 204 . The upraised collar 374 defines a second through hole 376 therein. The second through holes 376 of the upraised collars 374 correspond to the buckling structures 358 located at the undersides 356 of the short side walls 352 . The upraised collars 374 are essentially coplanar with one another. A diameter of each second through hole 376 is less than a diameter of the second hollow. A diameter of the second hollow is substantially equal to a diameter of the cap portion 3582 of the corresponding buckling structure 358 . Thus the depressed collars 204 and the upraised collars 374 have essentially the same structure, with the depressed collars 204 being oriented symmetrically opposite the upraised collars 374 .
Referring also to FIG. 8 , this shows engagement of the top plate 202 of the bezel 200 with the short side wall 352 , and engagement of the main body 3722 of the bottom plate 370 with the short side wall 352 , when the LCD device 2 is assembled. In a process of assembly of the LCD device 2 , the liquid crystal panel 210 is received in a first accommodating space cooperatively defined by the bezel 200 and the frame 350 . The BEF 322 , the diffusion film 321 , the LGP 333 , the reflector 360 are received in a second accommodating space cooperatively defined by the frame 350 and the bottom plate 370 .
The cap portions 3582 of the buckling structures 358 at the upsides 355 are vertically pressed into the first through holes 206 of the depressed collars 204 , and therefore are elastically deformed inwardly. The cap portion 3582 of each buckling structure 358 passes through the corresponding first through hole 206 . The cap portion 3582 then rebounds back to its original shape. The depressed collar 204 is thus substantially locked with the buckling structure 358 in the corresponding first notch 357 . With all the buckling structures 358 at the upsides 355 being locked with the corresponding depressed collars 204 , the top plate 202 firmly and securely abuts the upsides 355 . The bezel 200 is restricted from sliding or being pulled off the frame 350 . That is, relative movement of the bezel 200 and the frame 350 can be prevented. In this embodiment, the bezel 200 is locked with the frame 350 .
The cap portions 3582 of the buckling structures 358 at the underside 356 are vertically pressed into the second through holes 376 of the upraised collars 374 , and therefore are elastically deformed inwardly. The cap portion 3582 of each buckling structure 358 passes through the corresponding second through hole 376 . The cap portion 3582 then rebounds back to its original shape. The upraised collar 374 is thus substantially locked with the buckling structure 358 in the corresponding first notch 357 . With all the buckling structures 358 at the undersides 356 being locked with corresponding upraised collars 374 , the main body 372 firmly and securely abuts the undersides 356 . The bottom plate 370 is restricted from sliding or being pulled off the frame 350 . That is, relative movement of the bottom plate 370 and the frame 350 can be prevented. In this embodiment, the bottom plate 370 is locked with the frame 350 .
In summary, the bezel 200 is fixed to the frame 350 by engaging the depressed collars 204 with the corresponding buckling structures 358 of the short side walls 352 . A pressing operation generally in vertical directions only is needed. The bottom plate 370 is fixed to the frame 350 by engaging the upraised collars 374 with the corresponding buckling structures 358 of the short side walls 352 . A pressing operation generally in vertical directions only is needed. The bezel 200 and the backlight module 300 are therefore easily assembled into the LCD device 2 . When the LCD device 2 is disassembled, the cap portions 3582 of the buckling structures 358 are elastically deformed inwardly, and pressed through the corresponding first and second through holes 206 , 376 . Thus each of the bezel 200 and the bottom plate 370 is detached from the frame 350 , and the LCD device 2 can be easily fully disassembled. In addition, when the LCD device 2 is in the assembled state, because the cap portions 3582 are elastic, essentially no interspaces exist where the depressed collars 204 are engaged with the corresponding buckling structures 358 , and essentially no interspaces exist where the upraised collars 374 are engaged with the corresponding buckling structures 358 . Thus the LCD device 2 has good mechanical stability.
In alternative embodiments, each buckling structure 358 can have any of various other suitable forms. For example, the buckling structure 358 can have a partially or fully split configuration. In such case, the cap portion 3582 can include a pair of generally semi-annular or arcuate parts oriented symmetrically opposite each other. Preferably, the semi-annular or arcuate parts are separated by a gap. Alternatively, the cap portion 3582 can include three arc-shaped parts symmetrically arranged about a center thereof. Preferably, the arc-shaped parts are separated by three corresponding gaps. In another alternative embodiment, the buckling structures 358 can be disposed at the bezel 200 and the bottom plate 370 respectively, and the depressed collars 204 and the upraised collars 374 can be disposed at the frame 350 correspondingly.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
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An exemplary backlight module ( 300 ) includes a frame ( 350 ) and a bottom plate ( 370 ). One of the frame and the bottom plate includes a plurality of elastically deformable buckling structures ( 358 ), and the other of the frame and the bottom plate includes a plurality of protrusions ( 204, 374 ) corresponding to the buckling structures. When the bottom plate is attached to the frame, the bottom plate and the frame are pressed together along a first axis, and the buckling structures elastically deform and then elastically rebound such that the buckling structures are engaged with the protrusions and the bottom plate is fixed to the frame.
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BACKGROUND OF THE INVENTION
This invention relates to a device for withdrawing body fluids such as blood urine, and tissue fluid, which includes a withdrawal unit and a suction unit.
DESCRIPTION OF THE PRIOR ART
For withdrawing body fluids, such as blood, tissue fluid, fluid from body cavities, or urine, various medical devices are known, the most common being piston-fitted syringes, pipettes, and cannulas and catheters remaining at the site of withdrawal.
In many instances the parameter or parameters of the body fluid relevant for the particular test must be measured or monitored for a given period of time; in view of the rapid changes that often occur in parameters, it is frequently necessary to draw and analyze a sample of the body fluid at short intervals.
In certain hormone tests, for instance, blood samples must be taken every hour, which is extremely unpleasant for both patient and doctor, especially during the night. Examples in which blood sampling is required in order to obtain diurnal variation profiles include a number of hormone disorders, such as morbus cushing with disturbances in the diurnal cortison rhythm disturbances of growth and pubescence characterized by an absence of the nocturnal peaks of growth and sex hormones, and many others.
Another important application is the pharmaceutical industry, in which blood and tissue levels of drugs or their effects must be registered over a period of 24 hours.
In some instances it is possible to take blood samples via permanent arterial or venous access paths, which will at least avoid repeated puncturing several times a day; the patient still has to put up with unpleasant manipulations, however.
SUMMARY OF THE INVENTION
It is the object of this invention to propose a device for withdrawing body fluids which will relieve the patient from unpleasant manipulations and limit the work load of the medical staff, while permitting the parameters to be analyzed as well as their variations over time to be determined with adequate precision and identified with regard to their time of withdrawal.
According to the invention this is achieved by providing a storage system between the withdrawal unit and the suction unit, which is designed for receiving the body fluid and contains individual areas which may be separated from each other and hold the fluid fractions gathered at certain intervals, and which permit these individual fluid fractions to be clearly identified with regard to their time of withdrawal. In all tests in which an on-line analysis of the body fluid gathered is not possible for various reasons, the device described by the invention permits an analysis of the individual parameters of interest linked to the time of fluid removal, even at the end of an extended sampling process. A suitable withdrawal device is either a needle inserted in the blood stream, or a catheter, or a cannula in the catheter or as a branch-off--for instance, if urine is to be sampled. Suitable suction devices are all pumps generating a constant negative pressure, such as a roll diaphragm pump or other devices, for example vacuum connections.
A first variant of the invention may provide that the storage system be configured as a flexible tube connecting the withdrawal unit and the suction unit, and that a control unit be located at the inlet end of the tube in order to separate the individual fluid fractions, via which control unit a gaseous medium separating the individual fluid fractions can be introduced into the tube at given time intervals. This control unit may be configured as a valve connecting the storage system to the outside air after given periods of time, such that an air bubble can be sucked into the tube of the storage system, thus separating the individual fluid fractions.
Another variant of the invention provides that the withdrawal unit be connected to a distributor, and that parallel branch lines from this distributor be provided for the individual separable areas of the storage system, a control unit connecting these branch lines to the withdrawal unit one at a time, and all branch lines being connected to the suction unit via a manifold. In this variant each fluid fraction is only in contact with one specific branch line, which will largely eliminate the danger of a mixture or carryover of components of other fluid fractions.
In a preferred variant of the invention the withdrawal unit is provided with an ingoing line for a liquid to be introduced into the body, in addition to an outgoing line for the body fluid to be gathered, the ingoing line being connected to a pressure unit. With this variant it is possible to apply an agent preventing blood clotting, for example heparin, via the ingoing line of the withdrawal unit, which agent is continuously supplied by means of a pressure unit in the dose required for the blood sample.
For applications directly in the tissue the invention may provide that the withdrawal unit be configured as a subcutaneous needle/catheter, or vascular needle, with two concentric channels or lumes, whose one lumen is connected to the ingoing line while the other one is connected to the outgoing line. In this variant a perfusion liquid is applied directly into the tissue, and is gathered by fractions after its partial equilibration with the tissue parameters of interest, and finally analyzed for the parameters of interest. The use of endogenous or exogenous markers is recommended in order to determine the degree of interaction between perfusion liquid and tissue and to take it into account during the subsequent analysis. Equilibration needs to be only partial, since the perfusion liquid is analyzed with regard to both the parameter of interest and the characteristics of the endogenous or exogenous markers.
The subcutaneous needle or catheter may have an inner cannula connected to the outgoing line, which is surrounded by an outer cannula with openings towards the tissue, the latter being connected to the ingoing line. The device described can be used for determining, from the liquid fractions obtained, the tissue level of a hormone, or a substrate, such as blood sugar, or a drug, predominant at the time of withdrawal of the individual fractions.
In a simple device according to the invention the suction unit and the pressure unit are configured as a reciprocating pump, which is provided on the pressure side with a reservoir connected to the ingoing line and containing the liquid to be introduced into the body, and, on the suction side, with a suction chamber connected to the storage system. In the instance of applications differing with regard to their suction and pressure volumes, compensation vessels with concertina walls may be provided, which communicate either with the pressure-side or the suction-side part of the reciprocating pump. In the invention, the device may be provided with a receiving vessel for this purpose, preferably of variable capacity, which is connected to the reservoir for the liquid to be introduced into the body via a flow- regulating element. In this manner lesser amounts of liquid may be injected while fully maintaining suction power. For example, in applications necessitating the feeding of heparin, the ration of outgoing blood and ingoing heparin is between 10:1 and 500:1.
In order to simplify cleaning and handling of the device described by the invention, the proposal is put forward that the drive of the suction and pressure device as well as that of the control unit of the storage system, along with the corresponding control electronics, be located in a main housing, and that the storage system receiving the body fluid, and the suction/pressure units along with their connecting lines be located in a case which is detachable from the main housing. All components of the device in touch with the body fluid may be removed together with the case and may be replaced by another one. It has proved of advantage to use a U-shaped case, whose halves are situated one on either side of the main housing, each including a number of individual branch lines. For instance, branch lines may be provided for a total of 48 fluid fractions, ensuring a 24 hour test operation with fluid withdrawal every 30 minutes.
Since some body fluids to be gathered, or rather, their components, have high temperature sensitivity, it is proposed that the case containing the storage system, or rather, its halves be connected to an adjustable cooling unit, which has a container for a cooling gel, and whose wall facing the storage system has openings that are preferably regularly spaced, the cross-sections of these openings, which are controlled by a thermostat, admitting cooling air into the storage system. In this manner the individual fluid fractions are cooled to the required temperature until they are analyzed. Via the thermostat-controlled cross-sections of the openings the diminishing cooling effect of the cooling gel may be compensated.
In order to further simplify the device described by the invention, only one driving motor may be provided, actuating the suction and pressure device by means of a spindle drive and driving a camshaft via a reducing gear and a ratchet wheel. The cams of the noted camshaft cooperate with squeezer levers of the control unit attached to the main housing, each such cam-lifted lever giving access to one of the branch lines. No additional parts are required that would complicate the mechanism. It is also possible, of course, to locate the squeeze-off elements cooperating with the camshaft in the detachable case.
In order to be able to analyze the individual fractions they must be removed from the device and filled into individual test tubes. For this purpose the invention provides that the drive of the suction and pressure device may be reversed in order to permit removal of the individual fluid fractions from the storage system. In this instance the suction unit is converted into a pressure unit releasing the individual fluid fractions via the withdrawal system, i.e., needle or cannula.
Of course, the individual fluid fractions can also be tapped via a knob or crank cooperating with the suction/pressure device and the control unit of the storage system.
In order to efficiently prevent the individual fluid fractions from mixing--especially when they are separated by air bubbles--the invention proposes that the diameters of the branch lines, or rather, the flexible tube be kept small, such that adhesive forces acting between the inner walls of the storage system and the body fluid are larger than exterior forces acting upon the device, such as gravitation or additional accelerating forces. The diameters of the lines containing the fluid fractions should be selected such that the individual fractions are held in place by adhesive forces and remain in the place once defined in the storage system, no matter where the individual lines are situated, or which accelerating forces are acting upon them.
The invention finally provides that an electronic control system be provided with a display for entering a sequencing program. In this way the individual fractions of the fluid can be removed at individual, pre-selected points in time.
DESCRIPTION OF THE DRAWINGS
Following is a more detailed description of the invention as illustrated by the accompanying drawings, in which
FIG. 1 shows a device as disclosed by the invention,
FIG. 1a a detail A from FIG. 1,
FIG. 2 another device according to the invention,
FIG. 3 a variant according to FIG. 1,
FIG. 4 a section along line IV--IV in FIG. 3,
FIG. 5 a view from above, in the direction of arrow V in FIG. 3, parts of the cooling unit having been removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A device for withdrawing fluids from the body is shown schematically in FIG. 1. Between a withdrawal unit 2 configured as a subcutaneous needle or vascular needle 1 with two concentric channels, and a suction unit 3, there is situated a storage system 4 receiving the fluid fractions obtained. Departing from a distributor 5, which is connected with the outgoing line 6 of the withdrawal unit 2, the storage system 4 comprises a number of parallel branch lines 7 which are connected with the suction chamber 10 of the suction unit 3 via a manifold 8 and a connecting line 9 departing therefrom.
As is seen from detail A of FIG. 1 presented in FIG. 1a, the withdrawing unit 2 may be configured as a two-channel subcutaneous needle 1 whose inner channel 11 is in contact with the outgoing line 6, while the outer channel 13, which contains openings 12, is in contact with an ingoing line 14. The ingoing line 14 is connected to a reservoir 16 of a pressure unit 15, from which reservoir 16 a liquid to be introduced into the body, e.g., a perfusion liquid or an agent preventing blood clotting, etc., can be fed into the withdrawal unit 2.
Of course, the pressure unit 15, the ingoing line 14 and the two-channel needle 1 need not be included in a device which is only used for withdrawing blood; in this instance a conventional injection needle will suffice as a withdrawing device, or if a two-channel needle is used, the outer cannula need not have openings 12, since the blood is drawn trough the front opening of the needle. The inner cannula 11, which does not quite reach the tip of the outer cannula 13, may be used for adding an anticoagulant to the blood sample, for instance heparin.
A small number of openings 12 next to the tip of the outer cannula 13, can be of advantage in order to ensure that blood is drawn even if the front opening of the cannula touches the wall of the blood vessel.
In the variant shown here the suction unit 3 and the pressure unit 15 are combined in a reciprocating pump 17 whose suction chamber 10 is separated from the reservoir 16 by a piston 19 actuated by a driving rod 18.
By means of a control device 20 the branch lines 7 are connected to the outgoing line 6 one at a time, the control device 20 being in connection with the driving rod 18 of the piston pump 17 via a mechanical coupling (only shown schematically here), and being actuated together with the pump via a common drive 21. The arms 22 of the control device 20 are used to press shut both ends of those branch lines 7 that should not be opened to the body fluid.
Via a further line 23, in which is located a flow-control element 24, a variable capacity receiving vessel 25 is connected to the reservoir 16. Via the flow-control element 24 the amount of liquid flowing from the reservoir 16 into the ingoing line 14 may be varied while maintaining full suction power.
If the piston 19, and thus the control device 20, moves in the direction of the arrow 27, a partial vacuum is generated in the suction chamber 10, by which body fluid is pushed into the branch line opened by the control unit 20. If piston and control unit continue moving, this particular branch line is eventually pressed shut by the arms 22 of the control unit 20, and the branch line nearest in the direction of the arrow is opened. For drainage of the individual fluid fractions from the branch line 7 the drive unit simply is reversed.
In all subsequent variants identical parts have identical reference numbers. FIG. 2, for instance, shows a variant in which the storage system 4 is configured as a flexible tube 26 connecting the withdrawal unit 2 and the suction unit 3. In order to separate the individual fluid fractions 28, a control element 20 is placed next to the tube inlet 29, by means of which element 20 a medium separating the fluid fractions, for instance gas bubbles, may be introduced at given time intervals.
The control element 20 is presented schematically by an arm 31 with openings 32 uncovering an opening 33 in the vicinity of the tube inlet 29 as the control element continues moving in the direction of the arrow 27, upon which air from the environment is admitted briefly.
If the entrance of air or air/oxygen is undesirable, any other gas--provided that it does not affect the individual fluid fractions--may be introduced by means of such a control element, the only requirements being a suitable container and a feeder line.
Both in the variant of FIG. 1 and in that of FIG. 2 the control element 20 may be provided with a separate drive, for instance, a solenoid valve could be used, particularly in the variant of FIG. 2.
The variant shown in FIGS. 3 to 5 has a main housing 34 containing the drive 21 of the suction/pressure device configured as a reciprocating pump 17, and the corresponding control electronics 35 as well as a case 36 detachable from the main housing 34, in which are located the storage system 4, the suction and pressure units 3 and 15, and their connecting lines 5,6,8,14.
As is shown in FIG. 5, the case 36 is U-shaped, its halves 39, 40 being situated one on either side 37, 38 respectively, of the main housing 34, each half containing twenty-four single branch lines 7 with a capacity of 1 ml per line approximately. It is also possible to have cases 36 whose branch lines 7 have a capacity of 0.5 ml or 2 ml each, thus being suitable for the treatment of either children or grown-ups. The volume increase is obtained simply by increasing the number of windings of the branch lines 7, the cross-sections of the lines remaining small.
It is also possible, of course, to provide moulded channels for the individual fluid fractions, which are directly integrated in the case 36 and are furnished with a diaphragm in one particular place, which is acted upon by a squeezing element.
The case halves 39 and 40 containing the storage system 4 are surrounded by a cooling unit 41 shown in FIGS. 4 and 5, whose housing 42 is filled with a cooling gel 43. In order to safeguard continous cooling of the fluid fractions in the branch lines 7 at 4° C. approximately, the cooling gel must be refrigerated to a temperature of minus 30° C., and the housing 42 must be provided with an insulating layer 44 on its outside. The wall 45 of the cooling unit 41 facing the storage system 4 is provided with regularly spaced slits 46 whose opening cross-sections can be varied by shifting a shutter 48 provided with corresponding openings 47. The wall 45 and the shutter 48 must be made of a material with low thermal conductivity, and must be sufficiently strong in order to ensure that the temperature of the fluid fractions does not drop below the permissible minimum.
The shutter 48 may be actuated by a thermostat 49, for instance, a bimetallic element, which will keep the fluid fractions sufficiently cool even if the cooling effect of the cooling gel is diminishing. In the beginning, when the temperature of the cooling medium is very low, the shutter is closed almost completely, such that the fluid fractions are subject only to mild cooling; as the cooling medium loses its cooling effect, the shutter is opened correspondingly.
The device shown in FIGS. 3 to 5 has only one drive motor 50, which drives a cable 61 guided by rollers 60 of the piston 19 of the reciprocating pump 17 via the travelling part 52 of a spindle drive 51. Via a reducing gear 53 shown in FIG. 3, actuating a camshaft 55 by means of a ratchet wheel 54, squeezer levers 56 attached to the main housing 34 are actuated, each such lever 56 being lifted by a cam 57 of the camshaft 55, thus giving access to one of the branch lines 7 for receiving a fluid fraction. After the fluid fraction has entered each branch line 7 is clamped shut only in one place by a squeezer lever 56, the adhesive forces acting in the lines preventing the fractions from mixing upon a change in position of the case. The individual cams 57 actuating the squeezer levers 56 are positioned on the camshaft 55 basically along two helices, and are spaced 15 degrees apart.
In order to withdraw the individual fractions of the fluid the drive 21 of the reciprocating pump 17 can be reversed, the branch line which was filled first now being emptied first, and the direction of rotation of the camshaft being maintained.
After removal of the cooling unit 41 the line may be emptied by actuating a knob or crank 58 cooperating with the suction and pressure units 3 and 15 and the control element 20.
If samples are not taken continuously, it is recommended to use an electronic control system for the device, into which can be entered an individual sequencing program via a display 59. During a standstill of the suction unit 3 between two fluid withdrawals, blood clotting at the needle inserted in the bloodstream may be prevented by the addition of small doses of heparin via a small auxiliary pump. For this purpose the receiving vessel 25 could be used, which would only have to be furnished with a suitable driving means.
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A device for withdrawing body fluids such as blood, urine and tissue fluid includes a withdrawal unit, a suction unit, and a storage system receiving the body fluid between the withdrawal unit and the suction unit, the storage system being divided into separate areas holding the fluid fractions gathered at given intervals and permitting the individual fluid fractions to be identified with regard to their time of withdrawal. In this way tests requiring repeated sampling at short intervals are made easier for doctor and patient.
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REFERENCE TO PRIOR APPLICATION
This application is a continuation-in-part of application U.S. Ser. No. 789,967, filed Jan. 8, 1969, now abandoned.
BACKGROUND OF THE INVENTION
Phosphorus-containing compounds, such as phosphite compounds, are desirable for use as stabilizers for plastics and particularly for rubbers, especially for their metal chelating properties. Hindered phenols are also considered to be desirable as antioxidants, as evidenced by the wide use and acceptance of butylated hydroxy toluene. However, any efforts to form compounds which are combinations of hindered phenols and phosphite esters, to take advantage of the properties of both classes of compounds, have failed because the hindered phenol hydrogen is unreactive. This unreactivity of the hindered phenol is evidenced by the fact that reaction with sodium in liquid ammonia is necessary to replace the phenolic hydroxyl. U.S. Pat. No. 3,244,661 discloses triaryl phosphites, but these are not phosphite ester of hindered phenols. Thus, this relatively recent example of the state of the art supports the generally recognized theory that phosphite esters of hindered phenols are not obtainable.
It has now been found that phosphite esters of hindered phenols, particularly bis phenols, can be prepared and are particularly valuable as stabilizers for plastics and rubbers.
SUMMARY OF THE INVENTION
This invention relates to compounds which are phosphite esters of hindered bis phenols, their method of preparation, and their use as stablizers and antioxidants in polymers.
The novel compounds of the present invention are represented by the formula: ##SPC2##
Wherein X is sulfur or lower alkylene; e.g., a 1-4 carbon alkylene radical, preferably methylene; R is hydrogen or an alkyl radical; e.g., a C 1 -C 12 radical; and R 1 is an alkyl radical; e.g., C 1 -C 12 , preferably where the carbon adjacent to the ring is branched; e.g., a C 3 -C 12 radical, and more preferably, a tertiary radical, a cycloalkyl radical, or an X-linked alkylaryl radical, such as an alkyl-substituted phenolic radical having the formula: ##SPC3##
Where n is 1, 2, 3 or 4, preferably 1 or 2, and R' is an alkyl or cycloalkyl radical; e.g., an alkyl radical of R or R 1 , and preferably, where n is 2, R' is R 1 and is ortho to the hydroxyl group, where R' is R and is para to the hydroxyl group. The hydroxyl group may be ortho or para to the X-linked radical, preferably ortho. Where n is 1, the R' may be R 1 , or R, and preferably R 1 , ortho or para to the hydroxyl group. In all the formulas, each R, R' and R 1 may be the same or different.
Preferably then, R 1 may be: ##SPC4##
Phosphite esters of the hindered bis phenols may have structures of a hindered bis phenol or a hindered alkyl-phenolic bis phenol, or a mixture thereof where only one or more of the hindered bis phenol groups have one or two alkyl-phenolic substituents.
Some preferred compounds would be represented by the formulas as follows: ##SPC5## ##SPC6## ##SPC7##
where R 1 is a tertiary butyl radical, and R is a C 1 -C 12 radical, such as methyl, ethyl, tertiary butyl, hexyl, cyclohexyl, octyl, nonyl, etc., and where m is 1, 2 or 3.
The above formulas are illustrative of representative formulas of the invention, it being recognized that the methylene radicals may be X as previously defined and that the phosphorus-oxygen linkage may be to either end phenolic group or to the central phenolic group, or a mixture thereof, but not to three phenolic groups of the same alkylaryl-substituted tris phenol.
The compounds of the present invention are prepared by reacting a substituted phenol; e.g., an ortho-substituted phenol, preferably a p-alkyl ortho-substituted phenol; e.g., R 1 -substituted phenol, with an aldehyde or with a sulfur halide. The thus formed hindered bis phenol is then reacted, preferably under anhydrous conditions, with a trivalent phosphorus compound, preferably a phosphorus trihalide, such as phosphorus trichloride or phosphorus tribromide, or in a transesterification reaction, in bulk or in a solvent; e.g., a hydrocarbon, such as toluene.
DETAILED DESCRIPTION
The phosphite esters of the hindered bis phenols range from viscous liquids to solids depending upon the particular reactants and the nature of the reaction conditions.
The phenol employed in preparing the compounds of the present invention may be a hindered alkyl-substituted phenol (hindered), a hindered alkylene bis alkyl phenol or a hindered thiobis alkyl phenol. The aldehyde is preferably formaldehyde or paraformaldehyde, and the sulfur halide is preferably sulfur dichloride. The ratio of aldehyde or sulfur halide to phenol may range from 0.5-0.75 to 1, preferably 0.5-0.66 to 1, more preferably two moles of phenol are used per mole of aldehyde or sulfur halide. Where a hindered bis phenol is employed, of course, the step of reacting the phenol and the aldehyde is not employed. The reaction is catalyzed and is preferably carried out in a solvent system, more particularly, toluene. In order to avoid any hydrolysis of the product, any water present is removed, as by distillation, so that the reaction of the bis phenol and trivalent phosphorus compound is carried out under anhydrous or substantially anhydrous conditions. If the phosphorus compound employed is phosphorus trichloride, refluxing and sparging with an inert gas, such as nitrogen, or other suitable means are employed to remove any hydrogen chloride present. Preferred phenols include 6-t-butyl p-cresol, 6-t-butyl p-nonyl phenol, 6-nonyl p-cresol and 2,4 di-nonyl phenol.
The reaction of the bis phenol with the trivalent phosphorus compound may be carried out in bulk or in a suitable organic solvent, such as a hydrocarbon such as benzene, toluene, xylene, or mixtures thereof. The temperatures employed generally range from 40°C to 80°C, but the specific temperatures are selected with regard to the specific reactants employed. The ratio of trivalent phosphorus compound to bis phenol may range from 0.05-0.33 to 1. Preferably 3 moles of bis phenol are employed per mole of phosphorus compound. Although a phosphorus halide, like the trichloride, are preferably employed, other trivalent phosphorus compounds known to the art may be employed in the esterification or transesterification reaction.
Typical bis phenols which may be employed alone or in combination include, but are not limited to: 2.2'methylene bis (6-t-butyl p-cresol); 2,2'methylene bis (6-nonyl p-cresol); 2,2'methylene bis (6-octyl p-cresol); 2,2'methylene bis (6-t-butyl p-nonyl phenol); 2,6, di-tertiary butyl 4 (2-OH-3-nonyl-5-methyl benzyl) phenol; 2,6, di-t-butyl 4 (2-OH-3,5-nonyl benzyl) phenol; 2,2'-methylene bis (6 cyclopentene p-cresol); 2,2'-methylene bis (6 cyclopentene, p-nonyl phenol); 2,6 (2-OH-3-t butyl-5-methyl benzyl) p-cresol and their thio analogues; e.g., 2,2'thio bis (6-t-butyl p-cresol).
The phosphite esters of the invention include, but are not limited to: tris (methylene bis-2-(4 methyl-6-t-butyl phenol)-2'(4 methyl-6-t-butyl phenyl)) phosphite; tris(methylene bis-2-(4-nonyl-6-t-butyl phenol)-2'-(4-nonyl)-6-t-butyl phenyl)) phosphite; tris (thio bis-2-(6-t-butyl p-cresol)-2'-(6-t-butyl p-cresol)) phosphite; tris (methylene bis-2-(3,5 di-nonyl phenol) 2'-(4-nonyl-6 (3,5-di-nonyl-6-OH-benzyl) phenyl)) phosphite; and tris (methylene bis-2-(6 dicyclopentene p-cresol) 2' (6 dicyclopentene p-cresyl)) phosphite.
The compounds have utility as stabilizers and antioxidants for plastic resins and elastomers. They are particularly useful in hydrocarbon resins and conjugate diene elastomers subject to degradation such as polyolefins, such as C 2 -C 4 olefinic resins; e.g., polyethylene, polypropylene, ethylene-propylene copolymers, ethylene-propylene-diene copolymers and copolymers of styrene and butadiene; e.g., styrene-butadiene rubber (SBR).
The phosphite esters of hindered bis phenols are useful in preventing a change in color or mechanical strength properties during processing or storage of the particular material with which it is employed. The phosphite esters may be used alone or in combination with and as a component of other stabilizer systems and may be used in materials such as vinyl resins, such as polyvinyl chloride and vinyl chloride - vinyl acetate copolymers, polyesters; e.g., iso and terephthalactic acid glycol polyester resins, urethanes, acrylic resins; styrene resins, such as polystyrene and rubber-modified polystyrene, and in other polymers and resins which normally develop color on storage or during processing at elevated temperatures.
The compounds of the present invention are also suitable for use with natural and synthetic elastomers such as rubbery styrene-butadiene copolymers (SBR), acrylonitrile-butadiene copolymer (ABS), polybutadiene, butyl rubber, acrylonitrile-styrene copolymers, natural rubber, carboxylated elastomers, and ethylene-propylene rubbery copolymers. The compounds of the present invention are also particularly suitable for use in olefin resins such as polyethylene, polypropylene and propylene copolymers.
The compounds of the present invention may be added directly to the polymer by melting or dispersing onto the material to be stabilized or added to solutions or emulsions of the polymers. The compounds of the present invention are preferably employed at a level of about 0.1 to 5% by weight, preferably 0.5 to 2.0% by weight based on the weight of the material to be protected
The following nonlimiting examples illustrate the preparation of the novel compounds of the present invention:
EXAMPLE I
325 g of mono t-butyl p-cresol (2 moles) were dissolved in 200 g toluene to which was added 30 g of paraformaldehyde (1 mole) and 5 g of concentrated hydrochloric acid. The mixture was heated to 75°C for one hour, then refluxed under a Dean Stark trap until water distillation ceased. The reaction mixture was cooled to 60°C, and 45.6 g of phosphorus trichloride (0.33 moles) was added over a period of one-half hour. The mixture was stirred at 60°C for one-half hour, then heated to reflux, and refluxed for seven hours, to drive off hydrogen chloride. Nitrogen sparging, to assist in gas removal, was instituted when the gas evolution slowed down.
The reaction mixture is then cooled, and the white solid that separates is recrystallized from toluene and dried at 100°C. The melting point of the product, tris (methylene-bis-2-(6-t-butyl p-cresol) 2'-(6-t-butyl p-cresyl)) phosphite, was 126°C.
______________________________________Calculated for C.sub.69 H.sub.93 O.sub.6 P Phosphorus 2.95% Carbon 78.50% Hydrogen 8.95%Found Phosphorus 2.69% Carbon 77.40% Hydrogen 8.49%______________________________________
EXAMPLE II
550 g of mono t-butyl p-nonyl phenol (2 moles) was dissolved in 250 cc of toluene to which was added 30 g of paraformaldehyde (1 mole) and 5 grams of oxalic acid. The mixture was refluxed under a Dean stark water trap until substantially all water is removed.
The mixture was cooled to 65°C and 45.6 g of phosphorus trichloride (1/3 mole) was added over one-half hour. The mixture was held at 60°-65°C for one-half hour, then heated to reflux and refluxed seven hours. At the end of this time, nitrogen was sparged through the mixture to remove dissolved hydrogen chloride. The toluene was distilled off. The residue, tris (methylene-bis-2-(6-t-butyl p-nonyl phenyl)-2'-(6-t-butyl p-nonyl phenol)) phosphite, was an amber viscous liquid.
EXAMPLE III
328 g t-butyl p-crescol was dissolved in toluene. 67.5 g of sulfur monochloride (1 mole) was added dropwise over one-half hour and the mixture was heated to reflux for one hour.
The mixture was cooled to 60°-65°C, and 45.6 g of phosphorus trichloride (1/3 mole) was added over a period of one-half hour. The mixture was refluxed seven hours, and then sparged with nitrogen to remove hydrogen chloride. The mixture was cooled, and the solid, tris (this-bis-2- (6-t-butyl p-nonyl phenol)-2'-(6-t-butyl p-nonyl phenyl)) phosphite, which separated, was recrystallized from toluene.
EXAMPLE IV
930 g (1 mole) of 2,6 di-methylene para nonyl phenol bis 2,2' (4,6 di-nonyl phenol), prepared by the reaction of 1 molar quantity of nonyl phenol and twice molar quantities of paraformaldehyde, using an alkaline catalyst with di-nonyl phenol, is dissolved in 500 ml of toluene.
The solution is heated to 60°-65°C, and 45.6 g (0.33 mole) of PCl 3 is added slowly over a half-hour period. The mixture is refluxed for seven hours using a nitrogen sparge to facilitate removal of hydrogen chloride. The toluene is removed by distillation under reduced pressure leaving the product, tris (methylene bis-2-(4,6-di-nonyl phenol)-2'-(4 nonyl-6-(2 OH-3,5-di-nonyl benzyl) phenyl)) phosphite as a viscous dark amber liquid.
As stated above, that the compounds of the present invention could be prepared is entirely unexpected because of the nonreactivity of the hindered phenol hydroxyl, and in addition, because of the bulky molecules involved, it is also unexpected that the herein described reaction would occur because of steric hindrance.
The phosphite esters of the present invention are employed as stabilizers and antioxidants alone or in combination with other additives in gasoline, waxes, greases, natural and synthetic lubricating oils, jet fuel, heating fuel oil, and as a general petroleum product additive as a stabilizer, or for its phosphorus content.
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A phosphite ester of a hindered bis phenol of the formula: ##SPC1##
Wherein X is an alkylene radical or sulfur, R is hydrogen or alkyl, and R 1 is alkyl, cycloalkyl or an alkyl-substituted aryl radical, which compounds are useful as stabilizers for polymeric materials.
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TECHNICAL FIELD
The present invention relates to vacuum devices and more particularly but not exclusively to vacuum devices to clear outdoor surfaces.
BACKGROUND OF THE INVENTION
Mobile blower/vacuum devices are typically suspended on the user. That is, the motor and impeller and body of the device is suspended on the user with an elongated tube gripped by the user and directed at material to be drawn into the device. A bag is attached to the device downstream of the impeller so that material collected is delivered to the interior of the bag. The bag is air permeable so as to act as a filter.
It is known in respect of the above devices to alter the attachment of the tube so that the tube is downstream of the impeller so that the device acts as a “blower”.
A further modification includes the device having a first tube acting as a suction tube, and a second tube fixed thereto acting as a blower tube. A valve is then actuated to deliver air from the impeller to the blower tube or to the bag.
There is also known mobile vacuum devices that are provided with wheels. They have a base with a motor and impeller, with a duct extending from a forward edge of the device to the impeller, and a second duct extending from the impeller to a bag that stores the collected material.
The abovementioned devices that are suspended on the user are difficult to operate and are tiresome to use due to their weight.
The abovementioned vacuum device that is provided with wheels has the disadvantage that it cannot act as a blower.
OBJECT OF THE INVENTION
It is the object of the present invention to overcome or substantially ameliorate the above disadvantages.
SUMMARY OF THE INVENTION
There is disclosed herein a blower/vacuum device including:
a base to move over a surface to which the device is to cause an airstream to pass over;
at least one wheel fixed to the base to engage the surface to aid a user to move the device over the surface, the wheel having an axis of rotation;
a handle attached to the body and extending away from the body in a direction of extension generally normal to said axis, the handle being adapted to be gripped by the user so that the user may direct the device over said surface by rotation of said wheel;
a motor and impeller assembly to cause air to pass through the device;
a first duct extending to the assembly to deliver air thereto;
a second duct, the second duct extending away from said assembly so as to duct air therefrom;
a reservoir to store material collected by the device;
a third duct, said third duct extending away from said assembly to the reservoir to deliver air thereto together with any material passing through the first duct to the impeller;
a valve downstream of said impeller to direct therefrom to said second duct and/or said third duct; and wherein
said first duct has an inlet opening at a forward portion of said base, and said second duct has an outlet opening at said forward portion.
Preferably, said inlet opening faces downward toward said surface.
Preferably, said outlet opening directs air in a forward direction relative to said wheels and handle.
Preferably, said base at least partly defined said first duct.
Preferably, said valve includes a movable valve member and a portion to be gripped by a user to cause rotation of the valve member between a first position connecting the impeller with said second duct, and a second position connecting the impeller with said third duct.
Preferably, said valve member is rotated about a generally upright axis.
Preferably, said wheel is a first wheel, and said device includes a second wheel rotatable about said rotational axis but spaced axially from the first wheel.
Preferably, said device includes a third and a fourth wheel, the third and fourth wheels being spaced from the first and second wheels, the third and fourth wheels being castor wheels to engage said surface.
Preferably, said assembly has a rotational axis that is generally upright.
Preferably, said reservoir is supported by said handle.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein:
FIG. 1 is a schematic top plan view of a blower/vacuum device;
FIG. 2 is a schematic sectioned side elevation of the device of FIG. 1 longitudinally sectioned along the line 2 - 2 ;
FIG. 3 is a schematic side elevation of the device of FIG. 1 ;
FIG. 4 is a schematic top plan view of the device as shown in FIG. 3 sectioned along the line 4 - 4 ;
FIG. 5 is a schematic elevation of the device as shown in FIG. 3 sectioned along the line 5 - 5 ; and
FIG. 6 is a schematic illustration of a valve employed in the device of FIGS. 1 and 3
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the accompanying drawings there is schematically depicted a blower/vacuum device 10 . The device 10 includes a base 11 that would be provided with two rear wheels 12 that are rotatable about an axis 13 . Attached to and extending upwardly from the base 11 is a handle 14 that extends upwardly from the base 11 at an acute angle relative to the ground surface 16 upon which the device 10 is resting. The upper end of the handle 14 has a portion 15 to be gripped by a user and may include one or more controls.
Attached to and supported by the base 11 and/or handle 14 is a reservoir (bag or container) 17 that receives material collected by the device 10 .
The base 11 has a second pair of wheels 18 that are “castor” wheels that also engage the surface 16 , so that in combination with the wheels 12 the device 10 may be propelled across the surface 16 by a user gripping the handle 14 and pushing the device 10 in the intended direction of travel. Typically the forward direction of travel would be the direction 19 . Accordingly the base 11 has a forward (leading) portion 20 having regard to the forward direction of travel 19 .
Mounted on the base 11 is a motor and impeller assembly 21 including an electric (or internal combustion) motor 22 that would be typically provided with electric power by means of a flexible cable. The cable would be operatively associated with the controls on the handle 15 so that a user may select when the motor 22 is operative.
The motor 22 drives an impeller 23 , with the motor 22 and impeller 23 having a common generally upright rotational axis 24 . The axis 24 is generally normal to the axis 13 although displaced therefrom.
The impeller 23 is located in a housing 25 , the housing 25 having an inlet 26 through which air is drawn into the housing 25 . The air is caused to rotate by the impeller 23 and is delivered to a valve 27 .
Extending to the opening 26 is a first duct 43 that extends to an inlet opening 28 at the forward portion 20 . The opening 28 is downwardly facing so as to draw air in from adjacent the surface 16 . Accordingly material on the surface 16 is “drawn” into the opening 28 and delivered to the housing 25 . The first duct 43 is provided by the base 11 , the base 11 consisting of two plastic moulded halves 41 and 42 .
Extending from the valve 27 is a second duct 29 that extends to the reservoir 17 so as to deliver air thereto together with any material collected by the device 10 . Also extending from the valve 27 is a third duct 30 that extends to a nozzle 31 . The nozzle 31 has an outlet opening 32 again adjacent the forward portion 20 so that the opening 32 is adjacent the opening 28 . The nozzle 31 directs an airstream down toward the surface 16 at an acute angle relative thereto.
The nozzle 31 includes an airstream direction control device 33 that controls the direction at which air exits the nozzle 31 . The device 33 is rotatable about an inclined axis 34 , with the device 33 including a passage 35 , the position of which may be altered by gripping and turning the knob 36 by moving the knob 36 . By changing the position of the passage 35 , air exiting the nozzle 31 is changed in direction.
The valve 27 includes a portion 37 that is gripped by a user to select whether air leaving the impeller 23 is directed to the duct 29 or the duct 30 . hi particular the valve 27 includes a movable valve member 38 that is angularly movable about the axis 39 to determine whether air is delivered to the duct 29 or the duct 30 . The valve member 38 has a passage 40 that is changed in position to direct air to the duct 29 or the duct 30 . The axis 39 is generally upright and generally perpendicular to the axis 13 although displaced therefrom.
In operation of the above described device 10 , a user may select whether air exiting the housing 25 is delivered to the reservoir 17 so that the device 10 acts as a vacuum device, or to deliver air to the nozzle 31 so the device 10 also acts as a blower.
The above described device 10 has the advantage that should material be missed by the airstream exiting the nozzle 31 , that material is drawn into the opening 18 and again exits via the nozzle 31 . A further advantage of the above described device 10 is the ability to direct the airstream leaving the nozzle 31 .
A still further advantage of the above described device 10 is that the device 10 can be used as a vacuum or blower that is supported on wheels and therefore alleviates problems associated with such devices that are supported by the user.
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A blower/vacuum device includes a base supported on wheels. The device (10) has a reservoir (bag) that receives material collected by the device. Mounted on the base is a motor and impeller assembly that draws air inward and delivers the air (with collected material) to the bag. The assembly can also be operated to provide a forward delivery directed air stream.
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GENUS AND SPECIES OF PLANT CLAIMED
[0001] Hypericum kalmianum L.
VARIETY DENOMINATION
[0002] ‘PIIHYP-I’
BACKGROUND OF THE INVENTION
[0003] The present invention relates to a new and distinct cultivar of Hypericum plant, botanically known as Hypericum kalmianum L., and hereinafter referred to by the cultivar name ‘PIIHYP-I’. ‘PIIHYP-I’ is grown primarily as an ornamental for landscape use and for use as a potted plant.
[0004] ‘PIIHYP-I’ originated in 2008 from open-pollinated seed of ‘Cfflpc-1’ (unpatented) as part of a breeding program in Watkinsville, Ga. ‘PIIHYP-I’ originated and was selected by the inventor in a cultivated environment in Watkinsville, Ga. from the progeny of this open-pollination by continued evaluation for growth habit and foliage and flower characteristics.
[0005] Asexual reproduction of ‘PIIHYP-I’ by stem cuttings since 2010 has shown that all the unique features of ‘PIIHYP-I’, as herein described, are stable and reproduced true-to-type through successive generations of such asexual propagation.
SUMMARY OF THE INVENTION
[0006] Plants of the new cultivar ‘PIIHYP-I’ have not been observed under all possible environmental conditions. The phenotype may vary somewhat with changes in light, temperature, soil and rainfall without, however, any variance in genotype.
[0007] The following traits have been repeatedly observed and are determined to be unique characteristics of ‘PIIHYP-I’. These characteristics in combination distinguish ‘PIIHYP-I’ as a new and distinct cultivar: 1. Compact, mounding growth habit; 2. Silver-green foliage; 3. Bright yellow flowers from late spring to early summer; and 4. Cinnamon brown exfoliating bark.
[0008] Plants of ‘PIIHYP-I’ differ from plants of the parent, ‘Cfflpc-1’, primarily in growth habit and stem strength. Plants of ‘PIIHYP-I’ have a compact, mounding growth habit with strong stems that do not splay with age, whereas plants of ‘Cfflpc-1’ have an overall larger, rounded growth habit with stems that tend to splay with age, causing the plant to become open in the center.
[0009] Plants of the new Hypericum ‘PIIHYP-I’ can be compared to plants of the cultivar ‘Deppe’ (U.S. Plant Pat. No. 20,045), but differ primarily in foliage color. Plants of ‘PIIHYP-I’ have silver-green foliage, whereas plants of ‘Deppe’ have dark green foliage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying color photographs illustrate the flower and foliage characteristics and the overall appearance of ‘PIIHYP-I’, showing the colors as true as it is reasonably possible to obtain in color reproductions of this type. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description which accurately describe the colors of ‘PIIHYP-I’.
[0011] FIG. 1 illustrates the overall appearance and growth habit of a mature plant of ‘PIIHYP-I’ planted in the ground.
[0012] FIG. 2 illustrates the overall appearance of ‘PIIHYP-I’ plants growing in containers.
[0013] FIG. 3 illustrates a close-up view of the foliage of ‘PIIHYP-I’.
[0014] FIG. 4 illustrates a close-up view of the flowers of ‘PIIHYP-I’.
DETAILED DESCRIPTION
[0015] In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2007 Edition, except where general terms of ordinary dictionary significance are used. Plants used for the description were approximately 2-years-old and were grown in 11.8 L containers under outdoor conditions in Watkinsville, Ga.
Botanical classification: Hypericum kalmianum L., cultivar ‘PIIHYP-I’. Parentage: Hypericum kalmianum ‘Cfflpc-1’ (U.S. Plant Pat. No. 20,045). Propagation: stem cuttings. Time to initiate roots in summer: about 28 days at 32° C. Plant description: Deciduous flowering shrub; multi-stemmed; compact, mounding growth habit. Freely branching; removal of the terminal bud enhances lateral branch development.
Root description .—fibrous, well-branched. Plant size .—the original plant, now about four and a half-years-old in the ground, is about 61 cm high from the soil level to the top of the inflorescences and about 117 cm wide. First year stems having a diameter of about 1.5 mm. Shape: round. First year stem color.— 138C. Second year and older stems have a diameter of about 2 mm or more. Shape: 2-angled. Second year and older stem color.— 199C. Bark begins to exfoliate on second year and older stems. Stem strength .—flexible when young, becoming strong with maturity. Internode length .—about 1.3 cm. Trunk diameter .—about 2.8 cm at the soil line. Color: 200D. Bark: exfoliates in papery strips.
Vegetative buds:
Arrangement .—opposite. Shape .—leaf like, consisting of two to four preformed leaves. Size .—about 1.5 mm in length and about 2 mm in width. Color.— 146B.
Foliage:
Arrangement .—opposite, simple. Length: about 4.7 cm. Width: about 5 mm. Shape Linear to lanceolate. Apex: Obtuse. Base: Cuneate. Margin: Entire. Texture ( upper and lower surfaces ).—Smooth, glaucous. Venation pattern .—pinnate. Venation color of mature foliage (upper surface): color is 129A. Venation color of mature foliage (lower surface): 132D. Color of emerging foliage ( upper surface ).—124C. Color of emerging foliage (lower surface): 128B. Color of mature foliage (upper surface): 129A. Color of mature foliage (lower surface): 132D. Petiole length .—about 2 mm. Petiole diameter: about 1.5 mm. Petiole color (upper and lower surfaces): 136D.
Flowers:
Flower type and habit .—flowers are borne in multi-branched, terminal cymes. Inflorescence: about 6 cm in width and about 4 cm in height. Approximately 3 to 9 flowers per inflorescence. Natural flowering season: late spring to early summer, approximately May to June in Watkinsville, Ga. Individual flowers are showy for approximately 5 days, are self-cleaning, and are not fragrant. Flower buds .—about 5 mm in width, about 8 mm in length, and 1B in color. Flower size .—about 2.6 cm in diameter and about 1 cm in height. Peduncles .—about 3 cm in length, about 1.5 mm in width, and 138C in color. Pedicels: about 7 mm in length, about 1 mm in width, and 138C in color. Petals.— 5 in a single whorl. Length: about 1.2 cm. Width: about 6 mm. Shape: Oblong. Apex: Obtuse to truncate. Base: Attenuate. Margin: Entire. Color (upper and lower surfaces): 2B. Texture (upper and lower surfaces): Smooth, glabrous. Sepals.— 5 in a single whorl. Length: about 5 mm. Width: about 3 mm. Shape: Lanceolate. Apex: Acute. Base: Cuneate. Margin: Entire. Color (upper and lower surfaces): 144C. Texture (upper and lower surfaces): Smooth, glabrous.
Stamens:
Quantity/arrangement .—about 220 per flower. Filament: about 6 mm in length, less than 0.5 mm in width, and 5B in color. Anthers: about 1.5 mm in length, about 1 mm in width, and 6A in color. Pollen: produced in large quantities and is 6A in color.
Pistils:
Quantity .—one per flower. Size: about 6.5 mm in height and about 2.5 mm in width. Stigma: one per pistil, round in shape, about 0.5 mm in diameter, 149A in color. Style: 1 per pistil, about 2.5 mm in length, and 149A in color. Ovary: superior, one per flower, about 2.5 mm in width, about 3.5 mm in height, and 149A in color.
Fruit: The fruit is a dehiscent, 3 or 4-valved capsule, and persists throughout winter. Length: 7 mm. Width: 4 mm. Color: N199B. Seeds: very small, less than 0.5 mm in diameter, many per capsule, and 165A in color. Disease/pest resistance: Plants of the new Hypericum grown in the nursery and garden have not been noted to be resistant to pathogens and pests common to Hypericum.
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A new and distinct cultivar of Hypericum plant named ‘PIIHYP-I’, characterized by its compact, mounding growth habit, silver-green foliage, bright yellow flowers from late spring to early summer, and cinnamon brown exfoliating bark.
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FIELD OF THE INVENTION
This invention relates to energy efficient, rapid processes for the preparation of soaps from natural fats and oils via fatty acid methyl esters. More particularly, this invention relates to such processes utilizing intensive mixing and whereby such fats and oils are initially processed to form fatty acid methyl esters, and which are thereafter saponified to form fatty acid soaps.
BACKGROUND OF THE INVENTION
The methyl ester route for soap making involves first the preparation of fatty acid methyl esters from fats and oils (ester exchange) and subsequent saponification of the methyl esters to give soap with concomitant recovery of ensuing methanol, all according to the following. ##STR1##
Displacement of the glycerol in a fat by a low-molecular-weight alcohol, such as methyl or ethyl alcohol, is described in Bradshaw and Meuly U.S. Pat. No. 2,271,619. The process is said to produce methyl or ethyl esters directly from the fat, without intervening hydrolysis, and is said to take place at low temperatures. Although the reaction can be carried out in open tanks constructed of ordinary carbon steel, it is preferred to use sealed vessels. The fat must be clean, dry, and substantially neutral. It is heated to about 80° C. (176° F.), and to it is added commercial anhydrous (99.7%) methyl alcohol in which is dissolved 0.1-0.5% sodium or potassium hydroxide. The quantity of alcohol recommended is about 1.6 times that theoretically required for the reaction, although it is stated the alcohol may be reduced to as little as 1.2 times theoretical, if the operation is carried out in three steps. Alcohol amounting to more than 1.75 times the theoretical quantity does not materially accelerate the reaction and is said to interfere with subsequent gravity separation of the glycerol.
The Bradshaw patent contemplates use of the methyl esters to make anhydrous soap by a continuous process. It is stated the esters are saponified by caustic soda or caustic potash at a low temperature, and the methyl alcohol can be recovered for reuse. The methyl and ethyl esters of fatty acids are fluid, relatively stable, noncorrosive, and low-boiling derivatives, and in certain operations are preferred to free fatty acids. Methyl esters are preferred over the ethyl esters for reasons of lower cost of manufacture and better pyrolytic stability during processes such as fractional distillation.
It has also been reported that the alkali-catalyzed alcoholysis method is completely successful only if the fat is almost neutral and the reaction mixture is substantially anhydrous. Failure to comply with either of these conditions causes soap formation, which leads to a loss of alkalinity and also the building up of a gel structure that prevents or retards separation and settling of the glycerol.
The saponification of fatty methyl esters with alkalis to produce soap is well-known. Equipment for this purpose is available, for example, from Lion Corporation in Japan and Ballestra in Italy. In the known processes for manufacture of soap from fatty methyl esters, the methyl esters are first reacted with an alkali which results in the production of a soap mass containing both water and methanol. In the next step, excess water and methanol are removed. Several procedures are available to accomplish this step. For example, methanol can be removed by placing the soap mass as a thin film on a rotary drum. The soap mass is thus converted to soap flakes which can then be dried further by passing the flakes through an oven.
However, the following disadvantages are noted for the saponification of methyl esters to produce soap by such prior art methods:
1. The reaction of methyl esters with alkalis cannot be accelerated since all reactions are done at ambient pressures.
2. The concentration of soap in the soap mass is usually limited to the 60-70% range in order to have proper fluidity of soap mass to flow.
3. The drying of soap mass to remove methanol and excess water is highly limited and often not easily controllable.
4. The recovery of methanol for recycling into the system is rather complicated involving multistep processing.
SUMMARY OF THE INVENTION
It has been discovered that intensive mixing can be employed to produce fatty acid methyl esters from fat and oil stocks and that the fatty methyl esters so produced can then be saponified to form soaps, again by employing intensive mixing. As used herein, intensive mixing means introducing the raw materials normally employed in producing fatty methyl esters, i.e., suitable triglycerides, methanol and a caustic catalyst, such as NaOH, into an enclosed mixing vessel equipped with a condenser. The materials in the vessel are caused to rotate in a generally circular path while simultaneously bringing the material in contact with a separate rotating means mounted within the vessel, with the rotating means rapidly rotating either counter to or in the same direction as the initial direction of flow of the materials. The equipment useful to conduct the process is described in Myers U.S. Pat. No. 4,772,434 which is incorporated herein by reference. In preparing methyl esters, the vessel shown in the Myers patent is preferably equipped with a heating jacket whereby the temperature of the reactants may be raised, if desired. Additionally, it is desirable to equip the vessel with a syphon device to enable convenient removal of glycerin after the formation of the methyl esters. It has been found that fatty acid methyl ester formation occurs rapidly, usually in from about 15 to 60 minutes and that it is relatively easy to recover and purify any excess methanol as well as glycerin.
Preferably, an excess of about 10% methanol is employed over the stoichiometric amount required for ester formation, the excess methanol serving as a reaction solvent resulting in better mixing of the reactants. Also, although not necessary, it is preferable to add an acid at the end of the reaction to neutralize any caustic since there may be some free fatty acid formed which might react with caustic to form a soap. The presence of any soap might interfere with the separation of esters and glycerin after the reaction is completed. Such acidification also prevents any formation of triglyceride since the basic reaction is somewhat reversible. The process can use a wide variety of triglycerides although the reaction is somewhat slower as the molecular weight of the triglyceride increases, likely because the solubility of the methanol in the triglyceride decreases with the higher molecular weight materials. This can be easily overcome in the process by increasing the reaction temperature or increasing the speed of the intensive mixing. A further advantage of the process includes the recovery of a high concentration of glycerin--up to about 70% versus from 8-10% in the prior art steam splitting process. The glycerin is easily recovered from the mixer either by syphon or through centrifugation. Further, we find that less water is produced in the process which makes it easier to separate and purify the methanol which is left over after completion of the reaction. Another advantage to the process involving intensive mixing is that it is possible to use a lower grade triglyceride as a starting material and end up with a higher quality ester in that any so-called "color bodies" present in the triglyceride will migrate to the glycerine and thus not be present in the ester.
Similarly the use of intensive mixing to form soap from fatty methyl esters is a very rapid reaction. Although the esters and caustic (i.e. NaOH) are rather immiscible, the employment of intensive mixing results in superior contact of the reactants and thus a rapid reaction to form soap is the result. The speed of the reaction may be increased by applying pressure to the vessel as well as by increasing the speed of the intensive mixing. When the saponification is completed, vacuum can be applied to the vessel to remove the methyl alcohol. The application of vacuum may be continued to remove some of the water present in the soap, if that is desired. As earlier noted, the intensive mixing may be either counter-current or co-current. That is where the separate rotating means mounted in the vessel is rotating in a direction counter to the direction of flow of the material, counter-current mixing is taking place. Conversely, where the rotating means is rotating in the same direction as the initial direction of flow of the material, co-current mixing is taking place. Counter-current mixing is preferred.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of mixing equipment adapted to provide intensive mixing to produce fatty methyl esters from suitable fat and oil stocks and to saponify such esters to produce soap;
FIG. 2 is a horizontal view of the mixing equipment of FIG. 1;
FIG. 3 is a horizontal sectional view of the mixing equipment of FIG. 1 taken substantially on the line 3--3 of FIG. 1;
FIG. 4 is a fragmentary sectional view of the mixing equipment of FIGS. 1-3 taken substantially on the line 4--4 of FIG. 3;
FIGS. 5-7 are perspective views of rotors which can be employed in the mixing equipment shown in FIGS. 1-4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As used herein the expression "fat and oil stocks" means the raw materials which are customarily employed in soap manufacture such as the naturally occurring fats and oils which are triglycerides with three fatty groups randomly esterified with glycerol (tallow, lard, coconut oil, palm kernel oils and the like). The expression "saponify" or "saponification" means the neutralization with typical alkaline materials such as NaOH, KOH, soda ash and the like of fatty methyl esters to produce soap. By intensive mixing is meant causing a liquid stream of the reactants to rapidly move in a circular direction (e.g., counterclockwise) within a mixing vessel and at the same time bringing this rapidly moving stream into contact with mixing means rotating either in a direction counter to or in the same direction as the rapidly moving stream of reactants.
Referring to the drawings, FIG. 1 shows an embodiment of the mixing equipment useful in this invention and is designated generally at 10. The mixer 10 can be described as a mixing pan 11 (see FIGS. 3-4) rotatably mounted within sealable vessel 12 which is in turn, mounted on frame 13. The frame 13 is inclined so that the mixing pan 11 is tilted from the horizontal, thereby using gravity to assist in working the reactants within the mixing pan. Access to the interior of the mixer and more specifically to the mixing pan 11 is provided by hinged loading door 14, which is designed to provide an air tight seal when closed. The equipment is further provided with a water and air tight discharge gate 15 (see FIG. 3) at the bottom of the mixing pan. The discharge gate allows for removal of the soap after saponification has been completed.
The mixing pan 11 is driven by motor 16 mounted adjacent to the vessel 12. The required horsepower of this motor is of course dependent on the size of the mixing pan employed and the characteristics of the batch of ingredients being processed. As previously mentioned, the mixing pan is rotatably mounted and in the particular embodiment illustrated in FIG. 3, rotates in a clockwise manner. Mounted to the top of mixer 10 and eccentrically within mixing pan 11 is rotor assembly 17. The rotor assembly 17 is provided with a separate variable speed motor 18 (see FIG. 2) so that the speed of the rotor assembly may be changed as desired. Referring to FIG. 5, the rotor assembly consists of shaft 19 and attachment member 20 for securing the assembly to the drive motor. Various type of mixing tools may be mounted on shaft 19, of which FIGS. 5-7 are examples.
The mixing tool of FIG. 5 consists of generally circular plate 21 beneath which are mounted pins 22. FIG. 3 and FIG. 4 show a rotor assembly as disclosed in FIG. 5 and it is noted that the assembly is eccentrically mounted within the mixing pan and rotates in a direction counter to the direction of rotation of the mixing pan.
In FIG. 6 the mixing tool consists of two pairs of arms or knives 24 which are mounted at substantially right angles to each other and can be provided with balance weights 25 to counterbalance the assembly if such is necessary.
There is no significant difference in the mixing abilities of the mixing tools of FIGS. 5 and 6 although the mixing patterns are somewhat different.
It will be appreciated that a rotor assembly performs three functions in countercurrent or co-current mixing; that is, liquid mixing, and where soap is being made, dough chopping, and granulation of a soap product. A rotor assembly which is well adapted to perform these functions is shown in FIG. 7. The mixing tool of FIG. 7 consists of circular plate 21 beneath which are mounted pins 29. Above the plate 21 are mounted pins 30 and pins 31, pins 31 having horizontal chopper blades 32 secured to the top thereof. These chopper blades are mounted at the top of the pins 31, so as not to contact the fluid mixture until it is semi-solid and non-sticky.
Referring to FIGS. 1 and 2, it is seen that above the sealable vessel 12 is mounted a condenser 36. The mixing pan 11 (see FIGS. 3-4) is open to the condenser 36 via water vapor conduit 37. Although the interior of the condensor 36 is not shown, it is constructed in the conventional manner. Within the condenser 36 are a series of cooling tubes through which cooling water flows. The cooling water is introduced at the top of the condenser through coolant opening 38 and removed from the bottom of the condenser through a coolant drain (not shown). When the relatively warmer water vapor or excess alcohol from the mixing pan comes into contact with the cooling tubes (which must be cooled to a temperature below the dew point of the warm water vapor or alcohol vapor), the warm water vapor and/or alcohol condenses into liquid form on the tubes and the liquids can then be drained out of the condenser 36 through water drain 39.
A vacuum may be applied to the mixing equipment of FIGS. 1-4 in the following described manner. A vacuum port 40 on the condenser 36 is open to the interior chamber of the condenser, which in turn, is open to the mixing pan 11 via water vapor conduit 37. Any of the number of well known devices for creating a vacuum may be connected to the vacuum port 40 to create a vacuum. The term "vacuum" as used herein, refers to a pressure within the sealable vessel 12 which is below ambient atmospheric pressure. In the embodiment shown in FIGS. 1 and 2 a vacuum pump of conventional design was used. The sizing of the vacuum pump will depend upon the size of the mixing equipment used and on the desired vacuum level.
Mounted within mixing pan 11 are means to insure that the materials within the mixing pan are subjected to the intensive mixing operation. These means are secured to the to part of the mixing equipment immediately above the mixing pan and, as shown in FIG. 3 and FIG. 4 consist of a pan wall wiper 41 and pan bottom deflector 42 which is attached to the pan.
Referring to the equipment in FIGS. 1-4, in preparing the fatty acid esters, the fat or oil stock can be introduced through loading door 14 or through appropriate valves (not shown) mounted in the vessel 12. After the fat or oil stock has been introduced, rotation of mixing pan 11 is begun and thereafter methanol and caustic is added, either through the loading door or a valve. Rotation of the rotor assembly 17 is begun and intensive mixing of the reactants takes place. If counter-current mixing is employed, the rotation of pan 11 and rotor assembly 17 will be as shown in FIG. 3. A generally rotary movement of the reactants will be created much like a whirlpool as shown by the dotted arrow 50. The fat or oil stock employed in preparing the fatty methyl esters may be any of those customarily employed in making water soluble soaps. The fat or oil stock is preferably liquid ranging from their melting point to about 170° F. The methanol and caustic are then added and the reaction is allowed to proceed. The methanol and caustic may be added in several ways. The methanol can be heated to about 140° F. and the caustic mixed in with the methanol and then added to the mixer. Alternately, the methanol and caustic can be added separately, the methanol being added initially followed by caustic. The amount of methanol employed is about 10% in excess over the stoichiometric amount required for ester formation. Additionally, some acid such as sulfuric acid may be added after the reaction is complete to neutralize any free caustic. The addition of the acid is usually not necessary where the esters will be converted to soap after the removal of glycerin.
The preparation of soap from the fatty acid methyl esters employing intensive mixing is usually a very rapid process. Methanol is important to enhance the initiation of the reaction and caustic (NaOH) of 50% or 30% concentration work well. A higher concentration of caustic reduces the drying phase of the process, but a lower concentration (30%) facilitates homogenization during saponification.
In the following examples, all processing was conducted in a Model RO2 mixer manufactured by Eirich Machines of Hardheim, Germany. The mixer was equipped with a sealable vessel surrounding the mixing pan and a vacuum apparatus and condenser similar to that shown in FIGS. 1-4. In all examples, counter-current mixing was employed.
EXAMPLE I
Fatty methyl esters were prepared according to the following materials and procedure.
______________________________________60:40 palm:palm kernel oil 2000 gNaOH pellets 10 gMethanol 800 gSulfuric acid 20 g______________________________________
Procedure
Oil blend charged to mixer--pre-heated to 80° C.
Methanol heated to 60° C., caustic added to methanol.
Methanol/caustic mixture charged to mixer with pan and rotor low speed; --that is 36 rpm and 580 rpm respectively
Rotor to medium speed (1140 rpm) for about 3 minutes.
Heater turned on and 50 ml of methanol added.
Reaction completed after approximately one hour.
Added acid solution and reaction mixture allowed to separate.
Observations
Reaction appeared complete after 1 hour, layering noted.
Acid addition formed a white saponified layer between the glycerin and methyl ester layer--probably not necessary.
______________________________________Yield 1935 g Methyl ester 578 g Glycerin 2513 g Total Yield______________________________________
EXAMPLE II
Fatty methyl esters were prepared according to the following materials and procedures.
______________________________________60:40 palm:palm kernel oil 2000 gNaOH pellets 10 gMethanol 800 g______________________________________
Procedure
Methanol and caustic pellets pre-heated to 63° C. and charged to mixer.
Added oil blend to mixer, pan at 36 rpm, temperature 59° C.
Rotor at 1140 rpm.
Samples collected every 5 minutes to identify layering.
Reaction appeared completed after 30 minutes.
Allowed to mix an additional 30 minutes to monitor separation.
Product collected and allowed to separate.
Observations
Reaction facilitated in the presence of excess methanol and caustic.
Acid addition apparently not necessary.
______________________________________Yield - Methyl ester 1788 g Glycerin 383 g Total Yield 2171 g______________________________________
The yield was reduced because of sampling.
EXAMPLE III
Palm and palm kernel fatty acid methyl esters were saponified using the following materials and procedures.
______________________________________60:40 palm:palm kernel methyl ester 1200 g30% NaOH 580 gMethanol 220 g 2000 g______________________________________
Procedure
Methyl esters added to mixer--had been preheated to 80° C.; pan at 36 rpm
NaOH added to the pan
Methanol added slowly--at a temperature 71° C.
Rotor to high speed (1140 rpm) after reaction initiated--maximum temperature 79° C.
Excess methanol collected
Observations
Reaction went well--completed in 30 min.
Reflux condenser not 100% efficient, need chilled water rather than ambient temperature water
Vacuum applied too quickly--evacuated mixer to condenser
Moisture and volitile (M&V) (oven) 16.1% alk. 0.15% free fat as AV 214
EXAMPLE IV
Example III was repeated using 50% NaOH.
______________________________________60:40 palm:palm kernel ME 1200 g50% NaOH 348 gMethanol 220 g 2000 g______________________________________
Procedure
Methyl esters and methanol added to mixer, pre-heated to 63° C.
NaOH charged, pan on slow (36 rpm) initially, ambient temperature.
Rotor to high (1140 rpm) when reaction initiated--maximum temperature 77° C.
Excess methanol and water collected.
Observations
Reaction completed in 17 min., a faster rate than 30% NaOH
Collected 150 g methanol/H 2 O
M&V (oven) 14.7%, alk. 0.06%
Product more fibrous than Run #1
EXAMPLE V
Example IV was repeated without excess methanol.
______________________________________60:40 palm:palm kernel ME 1200 g50% NaOH 348 g 1548 g______________________________________
Procedure
Methyl esters added to mixer--preheated to 72° C.
NaOH charged slowly at 81° C.
25 g methanol added to initiate reaction
Rotor to high speed (1140 rpm) after several minutes at maximum temperature of 90° C.
100 g H 2 O added after one hour
No drying necessary
Observations
Reaction appeared to initiate with addition of methanol, however, it would not completely react.
Added 100 g water after one hour of mixing--product changed and appeared reacted--no drying necessary.
M&V (oven)--9.4%--alk. 0.28%
Extra methanol and/or water appeared to be important in completing the reaction
EXAMPLE VI
The process of Example III was repeated without excess methanol.
______________________________________60:40 palm:palm kernel ME 1200 gNaOH (30%) 580 g 1780 g______________________________________
Procedure
Added methyl esters to mixer, pre-heated to 80° C.
NaOH charged slowly at ambient temperature.
Rotor to high speed (1140), no reaction after about 10 minutes
Added 150 ml methanol in increments of 25 ml until reaction initiated at approximately 30 minutes
Collected excess methanol+H 2 O
Observations
Reaction occurred rapidly when 150 ml methanol was added to mixer and appears to be necessary for reaction. Maximum reaction temperature 87° C.--M&V (oven) 23.8%, alk. 0.04%.
EXAMPLE VII
______________________________________ Methyl ester 1200 g 50% NaOH 348 g Methanol 200 g 1748 g______________________________________
Procedure
Oil blend charged to mixer--heated to 79° C.
Methanol added--ambient temperature
NaOH charged slowly--pan rotor slow initially
Reaction completed in about 30 minutes
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A method of preparing esters and water soluble soaps using intensive mixing. The esters are prepared by reacting fats & oils with methanol containing caustic as a catalyst wherein the glycerin formed is removed. The resulting esters are saponified with caustic along with an additional amount of methanol to form the soap.
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SUMMARY OF THE INVENTION
This invention relates to a lock mechanism and will have particular application to a cylinder type lock.
The lock of this invention is provided with a barrel member for mounting to a lockable article, such as a door. Fitted within the barrel member is a rotatable plug which carries an actuator means for releasing and securing the lock upon rotation of the plug within the barrel member between locked and unlocked positions. A pair of tumblers are carried within the plug with at least one of the tumblers being engageable with the barrel member to secure the plug in its locked position against rotation. A key is inserted into a key slot in the plug and causes the tumblers to be shifted to release the plug for rotation within the barrel member into its unlocked position. At least one of the tumblers engages the key in such a manner to prevent the key's removal when the plug is rotated into its unlocked position. Additionally, the tumblers are so aligned within the plug that should an attempt be made to pick or force the lock open without the key by the insertion of a probe into the key slot one of the tumblers will interlock with the barrel member to prevent rotation of the plug.
It is an object of this invention to provide a lock mechanism which is of simplified but reliable structural form.
Another object of this invention is to provide a cylinder type lock in which the key which is utilized to unlock the lock cannot be withdrawn from the lock mechanism when the lock is open.
And still another object of this invention is to provide a cylinder lock having a cooperating tumbler mechanism which hinders picking or otherwise opening the lock without the use of a key.
Other objects of this invention will become apparent upon a reading of the invention's description.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of this invention has been chosen for purposes of illustration and description wherein:
FIG. 1 is a perspective view showing the lock of this invention mounted to a hatch cover.
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is a fragmentary sectional view of the lock shown secured with a key being inserted into the lock.
FIG. 4 is a fragmentary sectional view like FIG. 3 showing the key partially inserted into the lock.
FIG. 5 is a sectional view taken along line 5--5 of FIG. 1 showing the key fully inserted into the lock mechanism with the lock secured.
FIG. 6 is a fragmentary sectional view of the lock like FIG. 3 showing the lock open.
FIG. 7 is a cross sectional view taken along line 7--7 of FIG. 3.
FIG. 8 is a cross sectional view taken along line 8--8 of FIG. 6.
FIG. 9 is an exploded view of the component parts of the lock.
FIG. 10 is a view of the key as seen along line 10--10 of FIG. 9.
FIG. 11 is a cross sectional view of the key taken along line 11--11 of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment illustrated is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described in order to best explain the invention and its application and practical use to thereby enable others skilled in the art to best utilize the invention.
Lock 10 is shown in FIG. 1 as being connected to a door 12 which covers an opening in a frame 14. Door 12 is connected along one side edge by a hinge 16 to frame 14.
Lock 10 includes a barrel member 18 having a side wall 19. Barrel member 18 terminates at its outer end in a outturned flange 20 and at its inner end in an in-turned flange 22. A plug 24 is fitted rotatably within barrel member 18. One end of plug 24 is formed into a neck 26 which projects past the in-turned flange 22 of barrel member 18. Plug 24 includes a shoulder 28 which abuts in-turned flange 22 of barrel member 18 with the front end face 30 of the plug being positioned generally flush with outturned flange 20 of the barrel member. A cam part 32 is connected to neck 26 of plug 24 and is retained by means of a screw 34 and accommodating lock washer 36. Cam part 32 engages frame 14 upon plug rotation within barrel member 18 to secure door 12 in its closed position. In other applications of this invention, other types of cam or actuator parts could be used to secure the lock.
Plug 24 includes a pair of transversely oriented bores 38 and 40 which intersect the rotational axis of the plug. Bores 38 and 40 parallel one another, with bore 38 being located nearer end face 30 of the plug than bore 40. Bore 38 extends entirely through plug 24 while bore 40 preferably terminates within the plug. A tumbler 42 is slidably housed within bore 38 and a tumbler 44 is slidably housed within bore 40. Each tumbler 42 and 44 includes an enlarged head 46 and a shank 48. The length of tumbler 42 exceeds the length of bore 38. The length of tumbler 44 is less than the length of its receiving bore 40 to enable the tumbler to be entirely recessed within its bore.
Side wall 19 of barrel member 18 is interrupted at its inner surface by a pair of recesses, shown to be openings 50 and 52 in the preferred embodiment. Openings 50 and 52 extend through side wall 19 and are located so that opening 50 is aligned with bore 38 at the shank end of tumbler 42 and opening 52 is aligned with bore 40 at the head end of tumbler 44 when plug 24 is in its locked position, as shown in FIGS. 3, 4 and 5. A helical spring 54 surrounds each tumbler shank 48 and is compressed between head 46 of the tumbler and a part of plug 24 so as to urge the tumblers into protruding positions in contact with side wall 19 of barrel member as shown in FIG. 3. With plug 24 in its locked position, head 46 of tumbler 44 extends into opening 52 in the barrel member to secure the plug against rotative movement relative to the barrel member, and head 46 of tumbler 42 will contact the inner surface of barrel member side wall 19 with its shank 48 extending just to opening 50 in the side wall.
The outer surface of plug 24 is recessed at the location of heads 46 of tumblers 42 and 44 so as to form an arcuate key slot 56. A key 58 is provided to rotate plug 24 between its locked and unlocked positions. Key 58 includes a grip part 60 and a web part 62. Web part 62 is arcuate in cross section and is shaped and sized to fit complementally within key slot 56 next to barrel member side wall 19. Web part 62 of key 58 includes a center opening 64 and a notched opening 66 formed on a bevel at the end of the web part.
Lock 10 is mounted to door 12 by being inserted through an opening in the door with its flange 20 abutting the outside surface of the door. An annular retainer clip 68 is force fitted over the barrel member and pressed against the inside surface of the door. This method of securing the lock to door 12 is most advantageous when barrel member 18 and plug 24 of the lock are formed of a molded plastic material. It is to be understood that in other applications barrel member 18 could be bonded to the door by an adhesive or threaded to accommodate a nut which is turned onto the barrel member and brought to bear against the door. In those embodiments of the lock 10 in which the barrel member and plug 24 are formed of a metallic composition, the barrel member could also be welded or similarly bonded to the door.
With lock 10 secured to door 12, cam part 32 connected to plug 24 is located behind frame 14 when the plug 24 is located in its locked position, as shown in FIG. 2, to secure the door in its closed position. With plug 24 in its locked position and key 58 removed from key slot 56, any bladed instrument or pick inserted into the key slot in an attempt to manipulate tumbler 44 from opening 52 would first contact tumbler 42 and cause it to be urged rearwardly into its bore 38 with shank end 48 of the tumbler protruding into recess 50 such as illustrated in FIG. 4 to prevent rotation of the plug within the barrel member 18.
To utilize key 58 to rotate plug 24 between its locked and unlocked positions, the key is first inserted into key slot 56 in the direction of arrow 70 in FIG. 3. The beveled edge of notch 66 in the key first contacts tumbler 42 urging it rearwardly with its shank 48 protruding into opening 50, as seen in FIG. 4. Continued insertion of key 58 into slot 56 causes the beveled edge of notch 66 to contact tumbler 44 urging the tumbler into its recessed position within its bore 40 and out of opening 52, with tumbler 42 seating within opening 64 in the key, free of bore 50, as seen in FIG. 5. With key 58 fully inserted into slot 56 as shown in FIG. 5, plug 24 can be rotated, by a turning of key 58, into its unlocked position, as shown in FIGS. 6 and 8. This movement of plug 24 frees cam part 32 from contact with frame 14 and permits door 12 to be opened with key 58 serving as a handle for the door. As will be observed in FIGS. 6 and 8, head 46 of tumbler 42 projects into central opening 64 in key 58 with shank 48 of the tumbler being located next to an uninterrupted part of side wall 19 of barrel member 18 to prevent the removal of the key from slot 56. Thus any time plug 24 is rotated by key 58 so as to place tumbler 42 out of alignment with opening 50, the key will be prevented from being withdrawn from the key slot. When plug 24 is again rotated by key 58 into its lock position aligning tumblers 42 and 44 with openings 50 and 52, the key may be pulled from key slot 56 to allow head 46 of tumbler 44 to enter opening 52 after momentarily camming tumbler 42 into opening 50.
It is to be understood that the invention is not to be limited to the details above given, but that it may be modified within the scope of the appended claims.
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A lock which includes a barrel member for mounting to a lockable article, such as a door, and which carries a rotatable plug. The plug includes spring biased tumblers. A key is inserted into the plug and engages the tumblers to release the plug for rotation relative to the barrel member, with one of the tumblers interlocking with the key to prevent its removal from the plug when the plug is rotated to an unlocked position.
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FIELD
[0001] The present subject matter relates generally to methods for hydrocarbon conversion. More specifically, the present subject matter relates to methods for a catalytic process referred to as dehydrocyclodimerization wherein two or more molecules of a light aliphatic hydrocarbon, such as propane or propylene, are joined together to form a product aromatic hydrocarbon.
BACKGROUND
[0002] Dehydrocyclo-oligomerization is a process in which aliphatic hydrocarbons are reacted over a catalyst to produce aromatics, hydrogen and certain byproducts. This process is distinct from more conventional reforming where C 6 and higher carbon number reactants, primarily paraffins and naphthenes, are converted to aromatics. The aromatics produced by conventional reforming contain the same or a lesser number of carbon atoms per molecule than the reactants from which they were formed, indicating the absence of reactant oligomerization reactions. In contrast, the dehydrocyclo-oligomerization reaction results in an aromatic product that typically contains more carbon atoms per molecule than the reactants, thus indicating that the oligomerization reaction is an important step in the dehydrocyclo-oligomerization process. Typically, the dehydrocyclo-oligomerization reaction is carried out at temperatures in excess of 260° C. using dual functional catalysts containing acidic and dehydrogenation components.
[0003] Aromatics, hydrogen, a C 4+ nonaromatics byproduct, and a light ends byproduct are all products of the dehydrocyclo-oligomerization process. The aromatics are the desired product of the reaction as they can be utilized as gasoline blending components or for the production of petrochemicals. Hydrogen is also a desirable product of the process. The hydrogen can be efficiently utilized in hydrogen consuming refinery processes such as hydrotreating or hydrocracking processes. The least desirable product of the dehydrocyclo-oligomerization process is light ends byproducts. The light ends byproducts consist primarily of C 1 and C 2 hydrocarbons produced as a result of the cracking side reactions.
[0004] Traditionally, the dehydrocyclodimerization process includes a combined reactor feed having both C 3 and C 4 and recycled light paraffin feed components. While increasing the C 4 content in the feed increases yields, the pyrolytic coking becomes much more severe. Consequently, the on-stream efficiency is impacted adversely. Pyrolytic coking in the reactor internals is due to the formation of di-olefins mainly butadiene from n-butane and n-butene in the feed stream. Pyrolytic coking is most severe in the lead reactor due to lower hydrogen partial pressure and low aromatic components. Furthermore, reactivity of light aliphatic hydrocarbon increases with increasing carbon numbers. Therefore, conversions of butane takes place at significantly lower temperatures than propane, invariably a significant amounts of propane is not converted in C4 rich feed. Consequently, propane conversion is limited and a significant propane recycle is required.
SUMMARY
[0005] The claimed subject matter includes a process of producing aromatic hydrocarbons including passing a first light aliphatic hydrocarbon feed stream rich in C 2 -C 3 hydrocarbons to a first reaction zone having a first catalyst to form a first reaction zone effluent. The method further includes passing the first reaction zone effluent and a second light aliphatic hydrocarbon feed stream rich in C 3 -C 5 hydrocarbons to second reaction zone comprising a second catalyst to form second reaction zone effluent.
[0006] This method does not introduce a C 4 rich feed into the lead reactor, when C 2 -C 3 are present in the feed, but only to the lag reactors. By introducing a C 4 rich feed into lagging reactors, where both H 2 and aromatics are present, it greatly diverts the propensity to form butadiene, therefore reducing coke fouling. Furthermore, reducing contact times for C 4 conversions greatly mitigate the heavy aromatics formation, thus yields higher desirable aromatics products and mitigating the heavy fouling in the lag reactors. It is further recognized that introducing a C 3 rich feed into the lead reactor allows for more severe operating temperatures and lower pressures to drive the aromatics yields with no concerns of generating coking and thus fouling. This also minimizes the production of excessive light ends including C 1 and C 2 derived from the cracking of C 4 or heavier.
[0007] Additional objectives, advantages and novel features of the examples will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description and the accompanying drawings or may be learned by production or operation of the examples. The objectives and advantages of the concepts may be realized and attained by means of the methodologies, instrumentalities and combinations particularly pointed out in the appended claims.
DEFINITIONS
[0008] As used herein, the term “dehydrocyclodimerization” is also referred to as aromatization of light paraffins. Within the subject disclosure, dehydrocyclodimerization and aromatization of light hydrocarbons are used interchangeably.
[0009] As used herein, the term “stream”, “feed”, “product”, “part” or “portion” can include various hydrocarbon molecules, such as straight-chain, branched, or cyclic alkanes, alkenes, alkadienes, and alkynes, and optionally other substances, such as gases, e.g., hydrogen, or impurities, such as heavy metals, and sulfur and nitrogen compounds. The stream can also include aromatic and non-aromatic hydrocarbons. Moreover, the hydrocarbon molecules may be abbreviated C 1 , C 2 , C 3 , Cn where “n” represents the number of carbon atoms in the one or more hydrocarbon molecules or the abbreviation may be used as an adjective for, e.g., non-aromatics or compounds. Similarly, aromatic compounds may be abbreviated A 6 , A 7 , A 8 , An where “n” represents the number of carbon atoms in the one or more aromatic molecules. Furthermore, a superscript “+” or “−” may be used with an abbreviated one or more hydrocarbons notation, e.g., C 3+ or C 3−3 , which is inclusive of the abbreviated one or more hydrocarbons. As an example, the abbreviation “C 3+ ” means one or more hydrocarbon molecules of three or more carbon atoms.
[0010] As used herein, the term “zone” can refer to an area including one or more equipment items and/or one or more sub-zones. Equipment items can include, but are not limited to, one or more reactors or reactor vessels, separation vessels, distillation towers, heaters, exchangers, pipes, pumps, compressors, and controllers. Additionally, an equipment item, such as a reactor, dryer, or vessel, can further include one or more zones or sub-zones.
[0011] As used herein, the term “rich” can mean an amount of at least generally 50%, and preferably 70%, by mole, of a compound or class of compounds in a stream.
[0012] As used herein, the term “substantially” can mean an amount of at least generally 80%, preferably 90%, and optimally 99%, by mole or weight, of a compound or class of compounds in a stream.
[0013] As used herein, the term “active metal” can include metals selected from IUPAC Groups that include 6, 7, 8, 9, 10, and 13 such as chromium, molybdenum, tungsten, rhenium, platinum, palladium, rhodium, iridium, ruthenium, osmium, copper, zinc, silver, gallium, and indium.
[0014] As used herein, the term “modifier metal” can include metals selected from IUPAC Groups that include 11-17. The IUPAC Group 11 trough 17 includes without limitation sulfur, gold, tin, germanium, and lead.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The drawing figures depict one or more implementations in accord with the present concepts, by way of example only, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements.
[0016] FIG. 1 is a schematic depiction of an exemplary aromatic production process in accordance with various embodiments for the production of aromatics.
[0017] FIG. 2 is a schematic depiction of another exemplary aromatic production process in accordance with various embodiments for the production of aromatics.
[0018] FIG. 3 is a schematic depiction of yet another exemplary aromatic production process in accordance with various embodiments for the production of aromatics.
[0019] FIG. 4 is a schematic depiction of another exemplary aromatic production process in accordance with various embodiments for the production of aromatics.
DETAILED DESCRIPTION
[0020] The following detailed description is merely exemplary in nature and is not intended to limit the application and uses of the embodiment described. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
[0021] The various embodiments described herein relate to methods for hydrocarbon conversion. More specifically, the present subject matter relates to methods for a catalytic process referred to as dehydrocyclodimerization wherein two or more molecules of a light aliphatic hydrocarbon, such as, for example, propane or propylene, are joined together to form an aromatic hydrocarbon product. The basic utility of the process is the conversion of the low cost and highly available light aliphatic hydrocarbons, for example, C 3 and C 4 hydrocarbons, into more valuable aromatic hydrocarbons and hydrogen. This may be desired simply to upgrade the value of the hydrocarbons. It may also be desired to capitalize on a large supply of the C 3 and C 4 hydrocarbons or to fulfill a need for the aromatic hydrocarbons. The aromatic hydrocarbons produced can be used for various applications, including in the production of a wide range of petrochemicals, including benzene, a widely used basic feed hydrocarbon chemicals. The product aromatic hydrocarbons are also useful as blending components in high octane number motor fuels.
[0022] The feed composition for dehydrocyclodimerization process can vary depend on the compositions of light aliphatic hydrocarbon sources. In accordance with one aspect, the feed compounds to a dehydrocyclodimerization process include light aliphatic hydrocarbons having from 2 to 4 carbon atoms per molecule. The feed stream may comprise only one of C 2 , C 3 , and C 4 compounds or a mixture of two or more of these compounds. In one example, the feed compounds include one or more of propane, propylene, butanes, and the butylenes. The feed stream to the process may also contain some C 5 hydrocarbons. In one approach, the concentration of C 5 hydrocarbons in the feed stream to a dehydrocyclodimerization process is held to a maximum practical level, preferably below 5 mole percent. By one aspect, the products of the process include C 6 -plus aromatic hydrocarbons. In addition to the desired C 6 -plus aromatic hydrocarbons, some nonaromatic C 6 -plus hydrocarbons may be produced, even from saturate feeds. When processing a feed made up of propane and/or butanes, the a large portion of the C 6 -plus product hydrocarbons will be benzene, toluene, and the various xylene isomers. A small amount of C 9 -plus aromatics may also be produced.
[0023] In accordance with one aspect, the process includes increasing the amount of the more valuable C 7 and C 8 alkylaromatics, specifically toluene and xylenes, which are produced in a dehydrocyclodimerization reaction zone. By way of example and not limitation, a suitable system for carrying out the processes described herein includes a moving bed radial flow multi-stage reactor such as is described in U.S. Pat. Nos. 3,652,231; 3,692,496; 3,706,536; 3685,963; 3,825,116; 3,839,196; 3,839,197; 3,854,887; 3,856,662; 3,918,930; 3,981,824; 4,094,814; 4,110,081; and 4,403,909. The systems that may be used in the present process may also include regeneration systems and various aspects of moving catalyst bed operations and equipment as described in these patents. This reactor system has been widely employed commercially for the reforming of naphtha. fractions. Its use has also been described for the dehydrogenation of light paraffins.
[0024] The reaction zone operates under light aliphatic aromatization and alkylation (of aromatics with aliphatic hydrocarbon) conditions. Therefore the reaction zone operating conditions promote both the formation of aromatics from light hydrocarbons such as C 2 -C 8 paraffins, and naphthenes.
[0025] Conditions for aromatization of light hydrocarbons are known to favor low pressures and high temperatures. Hence for the dehydrocyclodimerization typical conditions are described in U.S. Pat. No. 4,642,402 A. The preferred metallic component is gallium as described in the previously cited U.S. Pat. No. 4,180,689. The balance of the catalyst can be composed of a refractory binder or matrix that is optionally utilized to facilitate fabrication, provide strength, and reduce costs. Suitable binders can include inorganic oxides, such as at least one of alumina, magnesia, zirconia, chromia, titania, boria, thoria, zinc oxide and silica. Suitable binders can include phosphate of aluminum, zircornium, chromium, titanium, boron, thorium, aluminum, zince, silicon, and the mixtures of thereof
[0026] Aromatization and alkylation conditions, according to the present subject matter, include temperatures ranging from about 350° C. to 650° C. In another approach, the aromatization and alkylation conditions may include a temperature between about 752° F. and 1328° F. (400° C. and 720° C.).
[0027] Aromatization and alkylation conditions according to the present example include pressures between 0.1 Psia to 500 Psia. In one approach, the aromatization and alkylation conditions may include pressures under 200 psia. The aromatization and alkylation conditions in another approach include a pressure between 5 Psia and 100 Psia. Without being limited by theory, hydrogen-producing aromatization reactions are normally favored by lower pressures and high temperatures, and accordingly in one approach conditions may include a pressure under about 70 psia at the outlet of the reaction zones rich in light aliphatic hydrocarbons.
[0028] FIG. 1 illustrates a flow diagram of various embodiments of the processes described herein. Those skilled in the art will recognize that this process flow diagram has been simplified by the elimination of many pieces of process equipment including for example, heat exchangers, process control systems, pumps, fractionation column overhead and reboiler systems, etc. which are not necessary to an understanding of the process. It may also be readily discerned that the process flow presented in the drawing may be modified in many aspects without departing from the basic overall concept. For example, the depiction of required heat exchangers in the drawing have been held to a minimum for purposes of simplicity. Those skilled in the art will recognize that the choice of heat exchange methods employed to obtain the necessary heating and cooling at various points within the process is subject to a large amount of variation as to how it is performed. In a process as complex as this, there exists many possibilities for indirect heat exchange between different process streams. Depending on the specific location and circumstance of the installation of the subject process, it may also be desired to employ heat exchange against steam, hot oil, or process streams from other processing units not shown on the drawing.
[0029] FIG. 1 illustrates one example of a flow scheme illustrating the claimed subject matter. With reference to FIG. 1 , a system and process in accordance with various embodiments includes a reaction zone 11 . A feed stream 10 enters the reaction zone 11 . The reaction zone 11 operates under typical aromatization of light hydrocarbon conditions in the presence of a typical aromatization of light hydrocarbon catalyst and produces a reaction zone product stream 28 . The reaction zone 11 can include one or more reactor vessels that contain an aromatization catalyst. These reactors can further be connected with and without additional separation equipment, and they may be connected in series or in parallel. The reaction zone 11 may generate at least one outlet stream 28 . The reaction zone outlet stream 28 may be sent to a separation zone 36 .
[0030] In the example illustrated in FIG. 1 , there are four reactors. However it is contemplated that there may be one or more reactors. The first reactor 12 contains a first catalyst 44 . The feed stream 10 enters the first reactor 44 , contacts the first catalyst 44 and forms a first reactor effluent 30 . The first reactor effluent 30 and stream 20 then enter the second reactor 14 , contact the second catalyst 46 and forms a second reactor effluent 32 . The second reactor effluent 32 and stream 22 then enter the third reactor 16 , contact the third catalyst 48 and forms a third reactor effluent 34 . The third reactor effluent 34 and stream 26 enter the fourth reactor 18 , contact the fourth catalyst 50 and form the reaction zone effluent 28 .
[0031] As discussed previously, the feed stream 10 includes light aliphatic compounds. Light aliphatic compound streams can be introduced to the reaction zone 11 in a form that could be liquid, vapor, or a mixture thereof By way of one example, the fresh portion of a C 3 aliphatic feed may be available in liquid form as liquefied petroleum gas.
[0032] In one example, the feed stream 10 includes only C 3 rich hydrocarbons. Therefore, only C 3 rich hydrocarbons enter the first reactor 12 . Streams 22 and 26 or streams 20 , stream 22 , and stream 26 include only C 4 rich hydrocarbons. Therefore, the C 4 rich hydrocarbons do not enter the first reactor 12 , but the C 4 rich hydrocarbons only enter the second and third, or second, third, and fourth reactors. By feeding the less reactive C 3 rich feed into the first reactor 12 and the more reactive C 4 rich into the second reactors 14 and third reactor 16 or the second reactor 14 , the third reactor 16 , and the fourth reactor 18 , a more desired aromatics yield results. This would also result in a reduced undesirable heavy aromatics, a reduced light ends including C 1 and C 2 , and minimal pyrolytic coking in the lead reactor and heavy fouling in the lagging reactor, while maximizing C 3 conversions.
[0033] In this example, where a C 4 rich feed is introduced into lagging reactors, where both H 2 and aromatics are present, it greatly diverts the propensity to form butadiene, therefore reducing coke fouling. Furthermore, reducing contact times for C 4 conversions greatly mitigate the heavy aromatics formation, thus yields higher desirable aromatics products and mitigating the heavy fouling in the lag reactors. It is further recognized that introducing C 3 rich hydrocarbon into the lead reactor allows higher operating temperature and lower pressure to drive the conversion of less reactive C 3 rich hydrocarbon to form aromatics. This also minimizes the generation of coke and thus fouling, and minimizes the production of excessive light ends including C 1 and C 2 , derived from the cracking of more reactive C 4 .
[0034] In one example, the feed stream 10 includes only C 3 hydrocarbons. Therefore, only C 3 rich hydrocarbons enter the first reactor 12 . Stream 20 and stream 22 include only C 4 rich hydrocarbons. Therefore, the C 4 rich hydrocarbons do not enter the first reactor 12 , but the C 4 rich hydrocarbons only enter the second and third reactors. Stream 26 includes only C5 rich hydrocarbons.
[0035] In this embodiment, C 5 is introduced into the lag reactors to minimize and eliminate the high propensity to produce pyrolytic coke and heavy fouling in the lead and lag reactors. C 5 is a feed component in the dehydrocyclodimerization technology has difficulty processing at significant percentages in the overall feed.
[0036] In one example, the feed stream 10 includes only C 2 rich hydrocarbons. Therefore, only C 2 rich hydrocarbons enter the first reactor 12 . Stream 20 includes only C 3 rich hydrocarbons. Therefore, the C 3 rich hydrocarbons do not enter the first reactor 12 , but the C 3 rich hydrocarbons only enters the second reactor 14 . Stream 22 and stream 26 include only C 4 rich hydrocarbons. Therefore the C 4 hydrocarbons only enter the third reactor 16 and the fourth reactor 18 .
[0037] In this embodiment C 2 , C 3 and C 4 rich hydrocarbons are introduced into reactors to attain descending contact times to maximize the overall aromatics yields with reducing light ends and heavy aromatics yields, while mitigating or eliminating pyrolytic coke and heavy fouling in the lead and lag reactor(s).
[0038] In another example, the feed stream 10 includes only C 2 rich hydrocarbons. Therefore, only C 2 rich hydrocarbons enter the first reactor 12 . Stream 20 includes only C 3 rich hydrocarbons. Therefore, the C 3 rich hydrocarbons do not enter the first reactor 12 , but the C 3 rich hydrocarbons only enters the second reactor 14 . Stream 22 includes only C 4 rich hydrocarbons. Therefore the C 4 rich hydrocarbons only enter the third reactor 16 . Stream 26 includes only C 5 rich hydrocarbons. Therefore a hydrocarbon stream rich in C 5 hydrocarbons only enters the fourth reactor 18 .
[0039] FIG. 2 is similar to FIG. 1 , however in FIG. 2 , there is a recycle stream 42 . The recycle stream contains C 2 -C 4 hydrocarbons. The recycle stream 42 containing C 2 -C 4 hydrocarbons may be mixed with the feed 10 as shown in FIG. 2 , but the recycle stream 42 may also enter any or all of the reactors as well. For example, the recycle stream 42 may also enter the second reactor 14 , the third reactor 16 , and the fourth reactor 18 .
[0040] As illustrated in FIG. 2 , once the recycle stream 42 is combined with the feed 10 , the feed 10 will contain whatever hydrocarbon is in the feed 10 plus the C 2 -C 4 hydrocarbons present in the recycle stream 42 . In one example, the feed stream 10 includes a hydrocarbon stream rich in C 3 hydrocarbons. Therefore, a hydrocarbon stream rich in C 3 hydrocarbons enters the first reactor 12 . As used herein, the term “rich” can mean an amount of at least generally 50%, and preferably 70%, by mole, of a compound or class of compounds in a stream. Stream 20 and stream 22 include a hydrocarbon stream rich in C 4 hydrocarbons. Therefore, a hydrocarbon stream rich in C 4 hydrocarbons does not enter the first reactor 12 , but a hydrocarbon stream rich in C 4 hydrocarbons only enters the second and third reactors. Stream 26 includes a hydrocarbon stream rich in C 5 hydrocarbons.
[0041] In one example, the feed stream 10 includes a hydrocarbon stream rich in C 2 hydrocarbons. Therefore, a hydrocarbon stream rich in C 2 hydrocarbons enter the first reactor 12 . Stream 20 includes a hydrocarbon stream rich in C 3 hydrocarbons. Therefore, a hydrocarbon stream rich in C 3 hydrocarbons does not enter the first reactor 12 , but the hydrocarbon stream rich in C 3 hydrocarbons only enters the second reactor 14 . Stream 22 and stream 26 include a hydrocarbon stream rich in C 4 hydrocarbons or C 4 hydrocarbons and C 5 hydrocarbons respectively. Therefore a hydrocarbon stream rich in C 4 hydrocarbons enters the third reactor 16 and the fourth reactor 18 or C 4 hydrocarbons enters the third reactor 16 and C 5 hydrocarbons enters the forth reactor 18 .
[0042] In this embodiment hydrocarbon streams rich in C 2 , C 3 , C 4 , and C 5 are introduced into reactors to attain descending contact times to maximize the overall aromatics yields with reducing light ends and heavy aromatics yields, while mitigating or eliminating coke and heavy fouling in the lead and lag reactor(s).
[0043] FIG. 3 is similar to FIG. 2 , however in FIG. 3 , the only feed entering the first reactor 12 is the recycle stream 42 . Stream 20 includes a stream rich in C 3 hydrocarbons entering the second reactor 14 . Stream 22 and stream 26 include hydrocarbon streams rich in C 4 hydrocarbons. Therefore a hydrocarbon stream rich in C 4 hydrocarbons enters the third reactor 16 and the fourth reactor 18 .
[0044] In yet another example illustrated in FIG. 3 , stream 20 includes a hydrocarbon stream rich in C 3 hydrocarbons entering the second reactor 14 . Stream 22 includes a hydrocarbon stream rich in C 4 hydrocarbons. Therefore a hydrocarbon stream rich in C 4 hydrocarbons only enters the third reactor 16 . Stream 26 includes a hydrocarbon stream rich in C 5 hydrocarbons. Therefore a hydrocarbon stream rich in C 5 hydrocarbons enters the fourth reactor 18 .
[0045] Any suitable catalyst may be utilized such as at least one molecular sieve including any suitable material, e.g., alumino-silicate. The catalyst can include an effective amount of the molecular sieve, which can be a zeolite with at least one pore having a 10 or higher member ring structure and can have one or higher dimension. Typically, the zeolite can have a Si/Al 2 mole ratio of greater than 10:1, preferably 20:1-60:1. Preferred molecular sieves can include BEA, MTW, FAU (including zeolite Y in both cubic and hexagonal forms, and zeolite X), MOR, MSE, LTL, ITH, ITW, MFI, MEL, MFI/MEL intergrowth, TUN, IMF, FER, TON, MFS, IWW, EUO, MTT, HEU, CHA, ERI, MWW, AEL, AFO, ATO, and LTA. Preferably, the zeolite can be MFI, MEL, WI/MEL intergrowth, TUN, IMF, ITH and/or MTW. Suitable zeolite amounts in the catalyst may range from 1-100%, and preferably from 10-90%, by weight.
[0046] Generally, the aromatization and alkylation catalyst includes at least one metal selected from active metals, and optionally at least one metal selected from modifier metals, and the alkylation catalyst (of aromatic with paraffin) includes optionally no active metals. The total active metal content on the catalyst by weight is about less than 5% by weight. In some embodiments, the preferred total active metal content is less than about 2.5%, in yet in another embodiments the preferred total active metal content is less than 1.5%, still in yet in another embodiment the total active metal content on the catalyst by weight is less than 0.5 wt%. At least one metal is selected from IUPAC Groups that include 6, 7, 8, 9, 10, and 13. The IUPAC Group 7 trough 10 includes without limitation chromium, molybdenum, tungsten, rhenium, platinum, palladium, rhodium, iridium, ruthenium, osmium, silver, and zinc. The IUPAC Group 13 includes without limitation gallium and indium. In addition to at least one active metal, the catalyst may also contain at least one modifier metal selected from IUPAC Groups 11-17. The IUPAC Group 11 through 17 includes without limitation sulfur, gold, tin, germanium, and lead.
[0047] It is contemplated that the first catalyst 44 , the second catalyst 46 , the third catalyst 48 , and the fourth catalyst 50 may be the same. However, it is also contemplated that the first catalyst 44 , the second catalyst 46 , the third catalyst 48 , and the fourth catalyst 50 may be different.
[0048] In the example illustrated in FIG. 1 , the reaction zone product stream 28 is sent to a light product separation zone 36 where one or more streams are generated. In this example, the light product separation zone 36 produces a first outlet stream 38 , a second outlet stream 42 , and a third outlet stream 40 . The first light product separation zone outlet stream 38 contains hydrogen, C 1 , and C 2 hydrocarbons. The second light product separation zone outlet stream 42 is rich in C 2 -C 4 hydrocarbons, which may include a purge of the C 2 -C 4 hydrocarbons, but also recycles the C 2 -C 4 hydrocarbons to be mixed with the feed 10 . The third light product separation zone outlet stream 40 contains C 6 + aromatics and is sent to the aromatic product separation zone. The light product separation zone 36 may have multiple separation vessels, each having multiple outlet streams comprising hydrogen, C 1 -C 2 hydrocarbons, and C 2 -C 4 hydrocarbons. These vessels may include but not limited to flash drums, condensers, reboilers, trayed or packed towers, distillation towers, adsorbers, cryogenic loops, compressors, and combinations thereof.
[0049] The recycle stream 42 containing C 2 -C 4 hydrocarbons may be mixed with the feed 10 as discussed previously, but the recycle stream 42 may also enter any or all of the reactors as well. For example, the recycle stream 42 may also enter the second reactor 14 , the third reactor 16 , and the fourth reactor 18 .
[0050] FIG. 4 illustrates yet another embodiment. In FIG. 4 , the third light product separation zone outlet stream 40 containing C 6 + aromatics is sent to the aromatic product separation zone, but a portion of the outlet stream 40 is also sent to the fourth reactor 18 , or the third reactor 16 and the fourth reactor 18 . Stream 40 containing C6+ aromatics can be further separated and having selective aromatics such as xylene, toluene or preferably benzene and toluene or most preferably benzene sent to the fourth reactor 18 or the third reactor 16 and fourth reactor 18 . In one embodiment the third reactor 16 and the fourth reactor 18 might have three streams entering each reactor. Therefore the aromatic rich product stream 40 is combined with the light aliphatic hydrocarbon stream to feed the third and fourth reactors containing the third and fourth catalyst, respectively. In another embodiment no light aliphatic hydrocarbons are introduced to the third reactor 16 or the fourth reactor 18 . In this embodiment, the alkylation of unconverted light aliphatic hydrocarbon with aromatics is maximized and the amount of unconverted hydrocarbons in minimized. Consequently, recycling the unconverted light aliphatic hydrocarbons is minimized or eliminated entirely. In this embodiment C 2 -C 3 rich feed enters the first reactor 12 and C 3 -C 4 rich feed enters the second reactor 14 or the second reactor 14 and the third reactor 16 .
[0051] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present subject matter and without diminishing its attendant advantages.
SPECIFIC EMBODIMENTS
[0052] While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the preceding description and the appended claims.
[0053] A first embodiment of the invention is a process of producing aromatics hydrocarbons comprising passing a first light aliphatic hydrocarbon feed stream rich in at least C2 hydrocarbons, C3 hydrocarbons, or a combination thereof to a first reaction zone having a first catalyst to form a first reaction zone effluent; and passing the first reaction zone effluent and a second light aliphatic hydrocarbon feed stream rich in at least C3 hydrocarbons, C4 hydrocarbons, C5 hydrocarbons, or a combination thereof to second reaction zone comprising a second catalyst to form second reaction zone effluent. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising passing a third light aliphatic hydrocarbon feed stream into a third reaction zone comprising a third catalyst to form third reaction zone effluent. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising passing a fourth light aliphatic hydrocarbon feed stream into a fourth reaction zone comprising a fourth catalyst to form fourth reaction zone effluent. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the first light aliphatic hydrocarbon stream is rich in C3 hydrocarbons the second light aliphatic hydrocarbon stream is rich in C4 hydrocarbons. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the first light aliphatic hydrocarbon stream is rich in C2 hydrocarbons the second light aliphatic hydrocarbon stream is rich in C3 hydrocarbons. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the first light aliphatic hydrocarbon stream is rich in C2 hydrocarbons the second and third light aliphatic hydrocarbon stream is rich in C3 and C4 hydrocarbons. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the first light aliphatic hydrocarbon stream is rich in C2 hydrocarbons the second, third and subsequent light aliphatic hydrocarbon stream is rich in C3, C4, and C5 hydrocarbons. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the overall conversion of individual light hydrocarbon are within 30% and 99.5% conversions. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the overall conversions of individual light hydrocarbon are within 50% and 95% conversions. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the catalysts in the first and second reaction zones are the same catalyst and the process is fixed bed, moving bed or fluidized bed reactor. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the catalyst in the first and second reaction zones are different, and the process is fixed bed reactor. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein a portion of light aliphatic hydrocarbon and heavy aromatics in the reactor effluent is separated from the aromatic product consisting of 6 to 10 carbon number with a single aromatic ring and the aromatic rich product stream is sent to the second reaction zone containing the second catalyst. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein a portion of light aliphatic hydrocarbon in the reactor effluent is separated from the aromatic product and combined with the first light aliphatic hydrocarbon to feed the first reaction zone containing the first catalyst. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein a portion of light aliphatic hydrocarbon consisting mostly C2, C3, and C4 in the reactor effluent is separated from the aromatic product and is fed to the first reaction zone containing the first reactor with the first light aliphatic hydrocarbon feeds to the second reaction zone containing the second reaction zone catalyst. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein a portion of aromatic products in the reactor effluent is separated from the light aliphatic hydrocarbon and heavy aromatic hydrocarbon and combined with the second or third reaction zone effluent to feed to the third or fourth reaction zone containing third or fourth catalyst. The aromatic product in claim 13 is benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, and preferably rich in benzene, toluene and xylene. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the pressure of the first reaction zone is between about 0.1 to about 50 Psia and the temperature is from 400° C. to 850° C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the pressure of the second reaction zone is between about 1 Psia to about 500 Psia and the temperature is from 300° C. to 750° C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the first catalyst and the second catalyst comprises a zeolite and at least one active metal-containing component. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the second light aliphatic hydrocarbon feed stream is rich in hydrocarbons having a carbon number greater than the carbon number in the first light aliphatic hydrocarbon feed stream.
[0054] Without further elaboration, it is believed that using the preceding description that one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of this invention, without departing from the spirit and scope thereof, to make various changes and modifications of the invention and to adapt it to various usages and conditions. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limiting the remainder of the disclosure in any way whatsoever, and that it is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.
[0055] In the foregoing, all temperatures are set forth in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.
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A process is disclosed for the aromatization of light aliphatic hydrocarbons, such as propane, into aromatic hydrocarbons. The process provides increased aromatics production, decreasing methane and ethane production, coke fouling and decreasing heavy aromatics. This improvement for the aromatization of light aliphatic hydrocarbons is achieved by introducing heavier of the light alphatic hydrocarbons in the feed to the lag reactors.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/040,559, entitled "Contoured Container Scoop and Scraper", filed Mar. 14, 1997.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to tools for handling of materials and more specifically to a tool for scooping and scraping materials stored within a cylindrical container.
2. Description of Related Art
The use of drywall materials for interior walls in residential and commercial buildings is widespread. Once the drywall sheets are affixed to studs, the seams between adjacent sheets are sealed with a tape and covered with a material generally called joint compound. Joint compound is typically sold in cylindrical containers such as buckets in a quantity such as five gallons. Application of the joint compound is achieved by scooping out a sizable portion and applying it on or in the worker's tools, where it is then applied to the drywall. Typically, workers use many different objects for performing the scooping operation, many of which are ill-suited to the task. Such objects include spoons, trowels, sticks, cups, scoops, and the like. These objects may be generally acceptable for simply obtaining joint compound from the bucket, but all leave substantial residue of the joint compound in the bucket which cannot be reached by the objects because of their shape. This results in waste of the joint compound. In addition, the objects used do not allow the worker to obtain most of the joint compound from the bucket without spillage. Use of these objects also results in unnecessary contact of the joint compound with the worker's hand or arm in any attempt to get at the residue. Furthermore, the action of scooping the joint compound out of the bucket is repeated many times by the worker, so a specialized tool for scooping and scraping in a clean and efficient manner would be valuable.
SUMMARY OF THE INVENTION
An embodiment of the present invention is a contoured container scoop and scraper tool for obtaining all product from a cylindrical container. The tool includes an elongated handle and a generally pie-shaped plate coupled to one end of the elongated handle and extending substantially perpendicularly thereto, the plate having a first edge projecting downwardly at an angle for use as a scraping edge.
Still other features and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein is shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive, and what is intended to be protected by Letters Patent is set forth in the appended Claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood with reference to the accompanying drawings in combination with the following description:
FIG. 1 is a perspective view of an embodiment of the present invention;
FIG. 2 is a rear view of the an embodiment of the present invention;
FIG. 3 is a side view showing an embodiment of the present invention conforming to the lower inside radial surface of a cylindrical container:
FIG. 3A is a top view showing an embodiment of the present invention conforming to both the bottom surface and the lower inside radial surface of a cylindrical container;
FIG. 4 is a side view showing an embodiment of the present invention conforming to the upper inside radial surface of a cylindrical container; and
FIG. 4A is a top view showing an embodiment of the present invention conforming to the upper inside radial surface of a cylindrical container.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made first to FIG. 1, which illustrates an embodiment of the present invention. A new and improved hand tool is shown which relates to the handling of scoopable bulk products from a cylindrical container in a most efficient and clean manner. The tool is designed to fit the inside radial contour of the container to facilitate the removal of various products with very little or no product residue remaining in the form of waste.
The contoured scoop and scraper tool 20 may be used to cleanly and efficiently scoop out materials, such as joint compound, from a cylindrical container (e.g., a bucket). The tool 20 allows the worker to obtain all of the joint compound from the bucket with a minimum of effort and mess. The tool 20 includes an elongated handle 22 having a contoured end plate 21 coupled to one end of the elongated handle. The handle may be cylindrical and hollow (i.e., tubular), cylindrical and filled, substantially flat, or any other shape providing the benefits of a sturdy handle. In various embodiments, handle 22 and end plate 21 are individual components and handle 22 is attached to end plate 21 by welding, gluing, riveting, or other suitable coupling methods known to those skilled in the art. Alternatively, handle 22 and end plate 21 may be integral. The handle and end plate may be formed of any suitable materials, such as plastic, wood, or metal, and any combination thereof
End plate 21 is a substantially planar component formed generally in a pie shape with the point of the pie shape being truncated. The end plate has a substantially straight upper edge 23 at a line where the pie shape has been truncated. The end plate has two opposing side edges 24 and 25 extending symmetrically from first and second ends, respectively of upper edge 23 at an angle of approximately 60 degrees. Lower edge 28 of end plate 21 is configured to as an arc to conform to the radius of the inside bottom wall of a cylindrical container 30 (such as a bucket), as illustrated in FIGS. 3 and 3A. Two opposing ends 26 and 27 of lower edge 28 found at the junctures of lower edge 28 and side edges 24 and 25, respectively, are trimmed perpendicular to upper edge 23, in essence removing the two outer protruding corners of the end plate adjacent to the arc of lower edge 28. The size of end plate 21 from upper edge 23 to lower edge 28 is approximately equal to the radius of the cylindrical container 30, depending on how much of the point of the pie shape has been truncated. The end plate 21 may be constructed in different sizes to fit different sized cylindrical containers. Side edge 25 is projected downwardly along a line 29 parallel to edge 25, at an angle of approximately 10 degrees from the plane of end plate 21, (as best illustrated in FIG. 2) to provide a scraping surface.
Modifications to the shape of the tool and the materials used for handle and end plate of the present invention are anticipated and included within the scope of the present invention.
The manner of using the tool 20 first involves the worker grasping the elongated handle 22, and with a downward motion, lowering the tool into the container 30, thereby filling the tool with product (e.g., joint compound). With an upward motion, the worker then removes product from the container, allowing lower edge 28 to follow the contoured inside edge of the container. The product is then dispensed according to its application. As the worker empties the container, the tool 20 can be periodically used to wipe the sides of the container clean by allowing the lower edge 28 of the tool to follow the contoured inside edge of the container in a downward motion around the entire inside perimeter of the container.
Some containers may be of a tapered type, and the tool 20 is then tilted towards the worker while raising or lowering the tool to conform it to the changing radius of the tapered container, as shown best in FIGS. 4 and 4A.
As the container becomes emptied the tool can also be used to clean the bottom of the container of remaining product. This is achieved by placing the tool in the bottom of the container and rotating the tool in a clockwise manner, as best shown in FIG. 3A. The projected side edge 25 serves as a blade to effectively remove product from the bottom of the container.
If a partially used container of product is to be stored, the tool can be used to thoroughly scrape the interior sides of the container in preparation for storage. This is achieved by allowing lower edge 28 of tool 20 to follow the contoured edge of the container in a downward motion. This procedure is repeated around the entire inside perimeter of the container until the sides are cleaned to the worker's satisfaction.
The handle 22 of the tool can be made at a length that would allow it to be stored inside the container 30, if desired.
It will be clear to one skilled in the art that tool 20 is capable of many applications and uses with assorted products, such as joint compounds, adhesives, and food service products.
The invention has been described in its presently contemplated best mode, and clearly it is susceptible to various modifications, modes of operation and embodiments, all within the ability and skill of those skilled in the art and without the exercise of further inventive activity. Accordingly, what is intended to be protected by Letters Patent is set forth in the appended Claims.
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Tool for obtaining materials out of a cylindrical container includes an elongated handle attached to or integrally formed with a generally pie-shaped end plate. The end plate has a downwardly projecting edge for use as a scraping edge when the tool is rotated within the container. The end plate has an edge in the shape of an arc to conform to the inside radial surface of a cylindrical container during use.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an original cover closing device employed for closing an original cover for use in a copy machine, a printing machine, or the like.
2. Related Art
In recent years, moldings of synthetic resins (plastic) are used as parts in every industrial machinery. The synthetic resins have so-called creep characteristics such that (1) when a predetermined force is continuously applied, deformation is advanced with elapse of time, and even if the force is stopped, the molding is not returned to the original state, (2) when a predetermined deformation occurs continuously, its repulsion is decreased with elapse of time, and (3) when time is further elapsed, the molding is destroyed. Among the synthetic resins, since zircon (polyacetal copolymer) has excellent mechanical characteristics including a creep resistance characteristic, it is used in various fields.
Consequently, zircon is also used for an original cover closing device. The following device using zircon is known.
There is an original cover closing device comprising: a supporting member made of zircon attached to the device body side; a spring case provided integrally with the supporting member; a slider housed in the spring case slidably to a cam part; and compression means constructed by a compression spring compressedly provided between the slider and the bottom of the spring case so as to press the slider to the cam side.
The attaching member and the supporting member made of zircon can be produced cheaper than those produced by press working iron plates and have an advantage that the members can be made in various forms. Although zircon has a high creep resistance characteristic among synthetic resins, when the members are used for many years, the following problems occur. A crack occurs especially on the bottom of the spring case and the bottom is fell out. The spring case is broken when a force is applied and broken pieces spread, and the like.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a closing device for an original cover, in which a spring case is not cracked or broken during use even when zircon by which especially the spring case can be cheaply manufactured and which has excellent mechanical characteristics is used.
In order to achieve the object, according to the invention, there is provided a closing device for an original cover, comprising a spring case made of a synthetic resin provided for either an attaching member attached to a machine body or a supporting member for holding an original cover rotatably connected to the attaching member via a hinge pin, and for controlling the rotation moment of the original cover attached to the supporting member by using the compression force of compression coil springs housed in the spring case, wherein a reinforcing frame member made of a metal for reinforcing the spring case which consists of a base plate portion for covering a bottom portion of the spring case, side plate portions bent from both ends of the base plate portion into a direction away from a plane of the base plate portion for covering both side portions of the spring case, and attaching holes opened at the side plate portions for connecting to the hinge pin. Thus, the reinforcing frame member is fastened to the spring case by inserting the hinge pin into the attaching holes.
According to the invention, there is also provided a closing device of an original cover, characterized by comprising: an attaching member attached to a machine body; a cam part mounted on the attaching member; a supporting member made of a synthetic resin which faces the cam part and supports an original cover rotatably connected to the attaching member via a hinge pin; a spring case made of a synthetic resin integrally formed with the supporting member and having a bottom portion and both side portions; a slider housed in the spring case slidably toward the cam part; a compression spring compressedly provided between the slider and the bottom of the spring case in order to press the slider toward the cam part; and a reinforcing frame member made of a metal for reinforcing the spring case and consisting of a base plate portion for covering a bottom portion of the spring case, side plate portions bent from both ends of the base plate portion into a direction away from a plane of the base plane portion for covering both side portions of the spring case, and attaching holes opened at the side plate portions for connecting to the hinge pin. Thus, the reinforcing frame member is fastened to the spring case by inserting the hine pin to the attaching holes.
According to the invention, there is further provided a closing device of an original cover, characterized by comprising: an attaching member serving as a leg to be attached to a machine body, provided in an upper part of a spring case made of a synthetic resin; a supporting member for supporting an original cover rotatably connected to the attaching member via a hinge pin; a cam part provided for the supporting member; a slider slidably housed in the spring case so as to face the cam part; a compression spring compressedly provided between the slider and the spring case in order to energize the slider to slide toward the cam part; and a reinforcing frame member made of a metal for reinforcing the spring case and consisting a base plate portion for covering a bottom portion of said spring case, side plate portions bent from both ends of the base plate portion into a direction away from a plane of the base plate portion for covering both side portions of the spring case, and attaching holes opened at the side plate portions for connecting to the hinge pin. Thus, the reinforcing frame member is fastened to the spring case by inserting the hinge pin to the attaching holes.
Other and further objects, features and advantages of the invention will appear more fully from the following description
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an original cover closing device according to the invention;
FIG. 2 is a plan view of the original cover closing device shown in FIG. 1;
FIG. 3 is a side view of a partial cross section of the original cover closing device shown in FIG. 1;
FIG. 4 is a cross section taken on line 4--4 of the original cover closing device shown in FIG. 3;
FIG. 5 is a perspective view of a reinforcing frame member;
FIG. 6 is a side view showing another embodiment of the original cover closing device according to the invention;
FIG. 7 is a plan view of the original cover closing device shown in FIG. 6;
FIG. 8 is a sectional side view of the original cover closing device shown in FIG. 6;
FIG. 9 is a cross section taken along line 9--9 of the original cover closing device shown in FIG. 8; and
FIG. 10 is a perspective view of another embodiment of the reinforcing frame member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following drawings show an embodiment of an original cover closing device A according to the invention. In FIGS. 1 to 5, reference numeral 1 denotes an attaching member having a leg 2. By detachably inserting the leg 2 into an insertion hole 3a opened in a rear upper end of the body of, for example, a copy machine shown by imaginary lines, the closing device is mounted on the machine body 3. Although a use example of the leg 2 is not shown in the diagram, for example, when an original is a thick original such as a book, by lifting the position of the insertion hole 3a to allow an original cover 4 shown by imaginary lines to cover the top face of the thick original in a horizontal state, it can be prevented as much as possible that external light enters an optical system of the machine body 3 and that internal light leaks to the outside. The attaching member 1 including the leg 2 are formed of a synthetic resin such as zircon and a cam part 5 is integrally formed on the attaching member 1.
Reference numeral 6 denotes a supporting member for supporting the original cover 4 having one end rotatably connected to the attaching member 1 via a hinge pin 7. The supporting member 6 is made of a synthetic resin such as zircon in a manner similar to the attaching member 1 and is formed integrally with a spring case 8 in a position facing the cam part 5. In the spring case 8, a slider 9 is slidably housed and a lever pin 10 attached to an end of the slider 9 comes into contact with the cam part 5. Compression means 13 comprising small and large coil springs 11 and 12 are compressedly provided between the slider 9 and the inner side of the bottom 8a of the spring case 8 to thereby always press the slider 9 to the cam part 5 side.
A reinforcing frame member 14 having an almost U- letter shape in cross section especially shown in FIG. 5 is attached to the outside of the spring case 8 so as to cover the outside of the bottom 8a. are coupled to the hinge pin 7. The reinforcing frame member 14 is made of a base plate portion 14a, side plate portions 14b, 14b bent from both ends of the base plate portion 14a to a direction away from a plane of the base plate portion and attaching holes 14c, 14c are opened in each end portions of the side plate portions 14b, 14b. In the member 14, a part which is in contact with the bottom 8a of the spring case 8 is made wider than the other parts to be adapted to a shape of the bottom 8a so as to cover the bottom 8a, an attaching hole 14d. The side plate portions 14b, 14b are fit on both side portions 8c, 8c of the spring case 8 and fastened or coupled to the hinge pin 7 by inserting the hinge pin 7 to the attaching holes 14c, 14c. A vis can be also used for this part.
The original cover closing device A according to the embodiment can be used by attaching the rear end of the original cover 4 to the supporting member 6 and by inserting the leg 2 of the attaching member 1 into the insertion hole 3a opened in the upper rear end of the machine body 3 as shown by imaginary lines in FIGS. 1 and 3. When the original cover 4 is opened/closed, the supporting member 6 rotates around the cam part 5 by using the hinge pin 7 as a fulcrum. Simultaneously, by a cooperative action of the cam part 5 and the slider 9 sliding on the circumferential face of the cam part 5 in a pressure contacting state, the original cover 4 is stably stopped and held at an intermediate open angle and is not naturally closed. As shown by the imaginary lines in FIG. 3, the original cover 4 is opened until the lever pin 10 of the slider 9 comes into contact with a stopper member 15.
When the original cover 4 is closed, the slider 9 which is in press contact with the cam part 5 slides in the direction of compressing the compression means 13. By the repulsion of the compression means 13, although the original cover 4 is not suddenly closed, the original cover 4 is energized in the closing direction. Consequently, the closing state of the original cover 4 is stable and occurrence of so-called a floating phenomenon which tends to occur when such compression means 13 is used can be prevented. The problem of the crack, coming off, and the like which tends to occur with long time of use on the bottom 8a of the spring case 8 is solved by reinforcing the spring case 8 by the reinforcing frame member 14 covering the outside of the bottom.
FIGS. 6 to 10 show another embodiment of the invention. In an original cover closing device B according to the embodiment, as an attaching member 21 is especially shown in FIGS. 6 and 8, for example, the leg attached to a machine body 22 side also serves as a spring case 23. A slider 24 is slidably housed in the spring case 23 and compression means 27 constructed by small and large coil springs 25 and 26 is compressedly provided between the slider 24 and the inner bottom of the bottom part 23a of the spring case 23.
Reference numeral 28 denotes a supporting member which is rotatably connected to the upper part of the attaching member 21 by a hinge pin 29. The supporting member 28 has a cam part 30 and the cam part 30 is in press contact with the slider 24. Reference numeral 35 is a lever pin which is actually in press contact with the cam part 30.
In the original cover closing device B according to the embodiment, as shown in FIGS. 6 to 8, the rear end of an original cover 31 shown by imaginary lines is attached to the supporting member 28 and a reinforcing frame member 32 having an almost U-letter shape in cross section is fit to the outside of the spring case 23 so as to cover the bottom 23a. The reinforcing frame member 32 is made of, for example, stainless steel. The reinforcing frame member 32 is made from a base plate portion 32a, side plate portions 32b, 32b bent from both ends of the base plate portion 32a to a direction away from a plane of the base plate portion, attaching holes 32c, 32c are opened in each end portions of the side plate portions 32b, 32b, and an attaching hole 32d is opened in a part covering the bottom portion 23a.
Both side plate portions 32b, 32b of the reinforcing frame member 32 are inserted into insertion holes 23c, 23c opened on both side portions 23b, 23b of the spring case 23. The base plate portion 32 fixed to bottom portion 23a of the spring case 23 by an attaching vis 36 through the attaching hole 32d. The side plate portions 32b, 32b is fit on side portions 23b, 23b of the spring case 23 and fastened or coupled to the hinge pin 29 by inserting the hinge pin 29 to the attaching holes 32c, 32c.
When the original cover 31 is opened, the supporting member 28 rotates around the hinge pin 29 as a fulcrum and the original cover 31 is stably stopped and held at an intermediate open angle by a cooperative action of the cam 30 and the slider 24 which slides in a press contact state to the cam part 30. The end 28a of the supporting member 28 comes into contact with a stopper member 33 attached to the upper part of the attaching member 21 by an attaching vis 34, thereby regulating the maximum open angle of the original cover 31.
In case of closing the original cover 31 as well, the original cover 31 is not suddenly closed by the cooperative action of the cam part 30 and the slider 24. The crack and breakage occurring on the bottom of the spring case 28 by the compression member 27 which repeats expansion and contraction with repetition of the opening/closing operation of the original cover 31 is prevented by the reinforcing frame member 32.
Having described our inventions as related to the embodiment shown in the accompanying drawing, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.
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In order to provide a closing device for an original cover in which a spring case is not cracked or broken during use even if zircon by which the spring case can be cheaply manufactured and which has excellent mechanical characteristics is especially used, the closing device has the spring case made of a synthetic resin provided for either an attaching member attached to a machine body or a supporting member for holding the original cover rotatably connected to the attaching member via a hinge pin and the rotation moment of the original cover attached to the supporting member is controlled by using a compression force of a compression coil spring housed in the spring case, wherein a reinforcing frame member made of a metal for reinforcing the spring case is attached to the spring case.
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This technology relates to the field of textiles, in particular the process of imparting colors and hues to fibers through the use of dyestuffs, and to methods of improving the efficiency of such processes.
BACKGROUND
Textiles are often dyed as part of the process of manufacturing clothing, furnishings and other consumer items that include textiles. However, the process of treating textiles with dyestuffs is often expensive, inefficient and environmentally unsound. For example, traditional cellulose dyeing processes require the use of large amounts of water, salt, alkali, and heat and can generate excessive pollution. In addition, the inefficiency of traditional textile dyeing results in poor ability to achieve a desired color, as well as problems such as bleeding and fading. These problems can lead to the need for large amounts of water, energy, dye, and chemicals to achieve desired colors, and therefore higher costs and greater environmental impact during the dyeing processes. The inefficiency of dyeing can further lead to undesirable bleeding or fading of colors before or after purchase and use by customers, resulting in poor quality control of dyed textiles.
SUMMARY OF THE TECHNOLOGY
In certain embodiments, the present technology is directed to a method of treating a cellulose fiber. The method comprises obtaining a fiber; and contacting it with a solution comprising about 0.5 to about 15 g/L of a wetting agent; about 5 to about 300 g/L of an alkaline composition; and about 5 to about 200 g/L of an ammonium salt. The technology provides for the solution to react. The fiber can be removed from contact with the solution; and extracted to a moisture content between 75% and 150%. The fiber can be stored in a closed container for a period of time, for example, about 8 to about 24 hours.
In other embodiments, the present technology is directed to a method of minimizing the amount of dye required to dye a fiber to a desired color. This method comprises treating the fiber by contacting it with a solution comprising a wetting agent, an alkaline composition and an ammonium salt. The fiber can be removed from contact with the solution and extracted to a moisture content between 75% and 150%. The fiber can be stored in a closed container for a period of time, for example, about 8 to about 24 hours. The fiber can also be removed from the closed container and neutralized, for example by rinsing in an acid solution. The fiber can then be dried and can be contacted with a dye until the fiber reaches a desired color.
This technology provides for dyeing fiber using less water, energy dye, chemicals and time. For example, the result may be up to 90% less water, 75% less energy, 50% less dye, 95% less chemicals, and one third the time compared to untreated fiber.
In other embodiments, the present technology is directed to a method of optimizing the retention of a dye in a fiber, comprising treating the fiber by contacting it with a solution comprising a wetting agent, an alkaline composition and an ammonium salt, including but not limited to a quaternary ammonium salt. The fiber can be removed from contact with the solution and extracted to a moisture content between 75% and 150%. The fiber can be stored in a closed container for a period of time, for example, about 8 to about 24 hours. The fiber can also be removed from the closed container and neutralized, for example by rinsing in an acid solution. The fiber can then be dried and can be contacted with a dye until the fiber reaches a desired color.
In other embodiments, the present technology is directed to a fabric comprising a fiber that has been pretreated with a solution comprising a wetting agent, an alkaline composition and an ammonium salt. The pretreatment step can include storage of the fiber in a closed container for a period of about 8 to about 24 hours.
In other embodiments, the present technology is directed to a method of dyeing a fabric, comprising treating a fiber by contacting the fiber with a solution comprising a wetting agent, caustic soda and an ammonium salt. The fiber can be processed into a yarn and knitter or woven to produce fabric. The fabric can be contacted with a dye to bring the fabric to a desired color such that the amount of dye required to bring the fabric to the desired color is at least about 25% less than the amount of dye required to dye a sample of the same fabric untreated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the results of a comparative test demonstrating a desired color of fabric dyed in accordance with a method of the present technology. It compares reflectance values of: (1) fabric made with untreated cotton fiber and dyed with conventional reactive dyeing procedure; (2) fabric made with exhaust pretreated fiber and dyed using “no chemical” dye procedure; (3) fabric made with inventive saturate/store pretreated fiber and dyed using “no chemical” dye procedure; and (4) fabric made with inventive saturate/store pretreated fiber and dyed using “no chemical dye procedure” with 25% reduction of dye and 50% reduction of dye.
FIG. 2 shows the results of a comparative test demonstrating a desired color of fabric dyed in accordance with a method of the present technology. It compares the level of dye exhaustion of (as listed from top to bottom in the legend on the right side of the Figure): 1) fabric made with untreated cotton fiber and dyed with conventional reactive dyeing procedure; (2) fabric made with exhaust pretreated fiber and dyed using “no chemical” dye procedure with 4% Everzol Navy ED; (3) fabric made with saturate/store pretreated fiber and dyed using “no chemical” dye procedure with 2% Everzol Navy ED (50% reduction of dye); (4) fabric made with saturate/store pretreated fiber and dyed using “no chemical dye procedure with 3% Everzol Navy ED (25% reduction of dye); and (5) fabric made with saturate/store pretreated fiber and dyed using “no chemical dye procedure with 4% Everzol Navy ED.
FIG. 3 shows transmittance values for conventional reactive dye bath and sequential rinse baths of fabric made with untreated cotton fiber and dyed with a conventional reactive dyeing procedure.
FIG. 4 shows a graphic representation of the reduction of color from conventional dye bath and each sequential rinse of fabric made with untreated cotton fiber and dyed with a conventional reactive dyeing procedure.
FIG. 5 shows samples of dye bath and sequential rinse baths of untreated cotton fabric dyed with a conventional reactive dye procedure (4% Everzol Navy ED).
FIG. 6 shows transmittance values for exhaust pretreatment dye bath and sequential rinse baths of fabric made with exhaust pretreated fiber and dyed using a “no chemical” dye procedure.
FIG. 7 shows a graphic representation of the reduction of color from dye bath and each sequential rinse of fabric made with exhaust pretreated fiber and dyed using a “no chemical” dye procedure.
FIG. 8 shows samples of dye bath and sequential rinse baths of exhausted pretreated cotton fabric dyed with a “no chemical” dye procedure (4% Everzol Navy ED).
FIG. 9 shows transmittance values for dye bath and sequential rinse baths of fabric made with an inventive saturate/store pretreated fiber and dyed using a “no chemical” dye procedure.
FIG. 10 shows a graphic representation of the reduction of color from dye bath and each sequential rinse of fabric made with an inventive saturate/store pretreated fiber and dyed using a “no chemical” dye procedure.
FIG. 11 shows samples of dye bath and sequential rinse baths of saturate/store pretreated cotton fabric dyed with a “no chemical” dye procedure (4% Everzol Navy ED).
FIG. 12 shows transmittance values for dye bath and sequential rinse baths of fabric made with saturated/stored pretreated fiber and dyed using a “no chemical” dye procedure and 25% reduction of dye (3% Everzol Navy ED).
FIG. 13 shows a graphic representation of the reduction of color from the dye bath and each sequential rinse of fabric made with saturated/stored pretreated fiber and dyed using a “no chemical” dye procedure and 25% reduction of dye (3% Everzol Navy ED).
FIG. 14 shows samples of dye bath and sequential rinse baths of saturated/stored pretreated cotton fabric dyed with a “no chemical” dye procedure and 25% reduction of dye (3% Everzol Navy ED).
FIG. 15 shows transmittance values for dye bath and sequential rinse baths of fabric made with saturated/stored pretreated fiber and dyed using a “no chemical” dye procedure and 50% reduction of dye (2% Everzol Navy ED).
FIG. 16 shows a graphic representation of the reduction of color from the dye bath and each sequential rinse of fabric made with saturated/stored pretreated fiber and dyed using a “no chemical” dye procedure and 50% reduction of dye (2% Everzol Navy ED).
FIG. 17 shows a sample of the dye bath of saturated/stored pretreated cotton fabric dyed with a “no chemical” dye procedure and 50% reduction of dye (2% Everzol Navy ED).
FIG. 18 shows transmittance values for the initial dye concentration and the residual dye bath of: 1) fabric made with untreated cotton fiber and dyed with conventional reactive dyeing procedure; (2) fabric made with exhaust pretreated fiber and dyed using “no chemical” dye procedure; (3) fabric made with saturate/store pretreated fiber and dyed using “no chemical” dye procedure with 4% Everzol Navy ED; (4) fabric made with saturate/store pretreated fiber and dyed using “no chemical dye procedure” with 25% reduction of dye and 50% reduction of dye; and (5) fabric made with saturate/store pretreated fiber and dyed using “no chemical dye procedure” with 50% reduction of dye.
FIG. 19 shows a graphical representation of the initial dye bath concentration and the residual dye bath of: 1) fabric made with untreated cotton fiber and dyed with conventional reactive dyeing procedure; (2) fabric made with exhaust pretreated fiber and dyed using “no chemical” dye procedure with 4% Everzol Navy ED; (3) fabric made with saturate/store pretreated fiber and dyed using “no chemical” dye procedure with 4% Everzol Navy ED; (4) fabric made with saturate/store pretreated fiber and dyed using “no chemical dye procedure” with 25% reduction of dye and 50% reduction of dye; and (5) fabric made with saturate/store pretreated fiber and dyed using “no chemical dye procedure” with 50% reduction of dye.
FIG. 20 shows comparisons of initial dye concentration and the residual dye bath of: 1) fabric made with untreated cotton fiber and dyed with conventional reactive dyeing procedure; (2) fabric made with exhaust pretreated fiber and dyed using “no chemical” dye procedure with 4% Everzol Navy ED; (3) fabric made with saturate/store pretreated fiber and dyed using “no chemical” dye procedure with 4% Everzol Navy ED; (4) fabric made with saturate/store pretreated fiber and dyed using “no chemical dye procedure” with 25% reduction of dye and (5) fabric made with saturate/store pretreated fiber and dyed using “no chemical dye procedure” with 50% reduction of dye.
FIG. 21 shows comparisons of dye baths of saturate/store pretreated cotton fabrics dyed with a “no chemical” dye procedure (4% Everzol Navy ED, 3% Everzol Navy ED and 2% Everzol Navy ED).
DETAILED DESCRIPTION
Throughout the disclosure of the present technology, the disclosures of all references cited are hereby incorporated by reference in their entireties. In the case of any conflicts in definitions between the disclosures of such references and the present disclosure, the present disclosure controls.
As used herein, the term “fiber” refers to a delicate, hair portion of the tissues of a plant or animal or other substance that is very small in diameter in relation to its length.
As used herein, the term “continuous grouping of fibers” refers to a continuous bundle of loosely assembled untwisted fibers.
As used herein, the term “yarn” means a continuous strand of textile fibers created when a cluster of individual fibers are twisted together.
As used herein, the term “fabric” means the final, finished textile material that results from the knitting or weaving of yarns produced from fibers and can ultimately be cut and sewn into clothing, furnishings or final item.
As used herein, the term “wet pickup” means the amount of solution retained by the fiber after complete saturation and extraction, and is calculated by the ratio of the wet weight of the fiber to its dry weight.
In certain embodiments, the present technology is directed to processes for the chemical application and modification of a fiber, for example a cellulosic fiber such as cotton fiber, to improve the receptivity and efficiency of dyeing with dyes.
In certain embodiments, a process in accordance with the technology herein will exhibit one or more of the following equations:
Equation I demonstrates the reaction of 3-Chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC), a particular quaternary ammonium salt, with an alkaline composition (in this case, caustic soda, NaOH) to produce epoxypropyltrimethylammoniumchloride (EPTAC), which is the epoxide of the CHPTAC. CHPTAC is not reactive with cellulose; therefore, it must first be converted into the reactive epoxide form of EPTAC before reaction with the cellulose.
Equation II demonstrates the reaction of the EPTAC with the cellulose molecule (ROH ++ ) to produce “positively charged cotton.” The reaction creates a permanent positive charged site on the cellulose molecule which can attract an anionic (negative charged) compound such as an anionic dyestuff. This is the pretreated cotton, which can then be contacted with the dyestuff.
Dyes
The embodiments of the technology herein contemplate the application of dyes to fiber that is desired to be dyed. In certain embodiments, anionic dyes (for example, reactive dyes, direct dyes and acid dyes) are found to be useful for the applications herein. In other embodiments, the dye used need not be anionic but may still be useful for the methods herein. For example, vat dyes and sulfur dyes are dyes that are found to be useful for certain embodiments herein. Any dye that exhibits an affinity for the fibers contemplated herein may be appropriate. For example, in embodiments wherein the fibers are cotton fibers, any dye that exhibits an affinity for cellulose may be useful for the present embodiments.
Fiber
Fibers useful for the embodiments herein include, but are not limited to, cellulosic fibers such as cotton fiber (either as separate fibers or in the form of a continuous grouping of fibers or yarn), linen, viscose, bamboo, jute, hemp, flax and any other cellulosic fiber. After pretreating the fiber it can be dyed, or the fiber can be spun into yarn which could be dyed, or the yarn could be knitted or woven into fabric which could be dyed, or the fabric could be made into a finished product, for example a garment, which could be dyed. The fiber may be pretreated in its free form, or in the form of a continuous grouping of fibers.
Pretreatment Solution
In various embodiments, the methods herein comprise contacting a fiber with a pretreatment solution before contacting the fiber with the dye. The pretreatment solution can advantageously impact the fiber in a manner that enables it to exhibit superior properties when subsequently contacted with the dye, such as, for example, an increased ability to retain the dyestuff such that a lower amount of dyeing solution is required to achieve a desired hue; superior ability of the final fabric to retain the dye without fading over time and after multiple washings; and lessened environmental impact, water use or energy use.
The pretreatment solution comprises, in certain embodiments, a wetting agent; an alkaline composition such as alkali hydroxide or alkali metal hydroxide e.g., sodium hydroxide (caustic soda) or potassium hydroxide (potash caustic), and a salt, such as an ammonium salt (for example, a quaternary ammonium salt), as well as any other alkali hydroxide, including lithium hydroxide, rubidium hydroxide or cesium hydroxide.
The wetting agent may comprise, in certain embodiments, a blend of anionic and nonionic surfactants, for example one that is commercially available under the trade name “Cottoclarin 88 ECO” from Pulcra Specialty Chemicals, Ltd. of Shanghai, China. Such composition has been found to be useful for generating instantaneous wetting and penetration of the fiber. Such compositions are particularly known to be useful for cotton fiber.
In certain embodiments, the fiber may be contacted with the pretreatment solution in any of numerous ways; for example, it has been discovered that desirable results can be achieved when the pretreatment solution is applied in a padding process. The fiber can, for example, be saturated in a trough and passed through rollers or padders. The fiber can be contacted with the pad for a period of time, for example, about 15 to about 30 seconds. Spray or foam applicators can also be used—that is, the pretreatment solution may be applied to the fiber by spraying or foaming directly onto the fiber.
In certain embodiments, the pretreatment solution includes a composition comprising an amino group—for example, an ammonium salt. Examples of useful ammonium salts for the embodiments of the present technology include, e.g, quaternary ammonium salts. An exemplary quaternary ammonium salt is 3-Chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC, also known as PTAC) and which is available under the trade name “Catdye” from MFI Technologies, Inc. of Mooresville, N.C., USA.
In certain embodiments, the pretreatment solution includes an alkaline composition. Examples of useful alkaline compositions include, but are not limited to, sodium hydroxide (caustic soda), potassium hydroxide and the like, as well as blends of any of the foregoing.
Closed Container
In certain embodiments, the methods and processes of the present technology further comprise the step of storing the fiber in a film or closed container, after the contact of the fiber with the pretreatment solution. As used herein, “closed container” means a film, container or vessel that is substantially separate from contact with the outside environment. In various embodiments, the film can be a plastic film and the closed container can be a vessel or tank with a lid or any other holding container in which the sample of fiber may be stored to substantially prevent exposure to the ambient air and environment and to substantially prevent the introduction of impurities or removal of any portion of the samples of fiber or the solution in which they are stored
In various embodiments, the fiber is stored in the closed container for a period of time of about 8 to about 24 hours, about 12 to about 20 hours, or about 15 to about 18 hours. In certain embodiments, the closed container may be heated; however, an advantage of this process step is that desirable results can be achieved without the addition of heat—that is, the reactions can take place at room temperature.
Acid
In certain embodiments, after the fiber has been stored for the required period of time in the closed container, it is taken out of the storage unit and then contacted with an acid solution. This contact will have the effect of bringing the pH of the fabric down to an acidic level after exposure to the alkaline composition. This is particularly useful because known methods for dyeing fabrics often result in high amounts of alkaline effluent; thus, adding acid to the effluent of any pretreatment step can neutralize the solutions and minimize their environmental impact.
In various embodiments, the fiber may be contacted with a continuous stream of an acid solution. In the embodiments herein, any acid solution that is effective in lowering the pH of the liquid present in the fiber may be useful for the purposes discussed herein. It has been found that organic acids such as citric acid are particularly useful; however, other acids such as, e.g., acetic acid or phosphoric acid may also be used. As used herein, “the pH of the fabric” refers to the pH of the retained liquid in the fabric; this is measured by collecting the liquid that flows out of the fabric (by collecting it as it drips, or optionally by applying mechanical pressure to the fabric, e.g., by squeezing, rolling or the like) and then measuring the pH of the liquid that flows out of the fabric. In various embodiments, the amount of acid used is sufficient to maintain the pH of the fabric under about 7.0, under about 6.5, under about 6.0, under about 5.0, under about 4.8, about 4 to about 6.5 or about 4 to about 5.
After completion of the methods of the various embodiments discussed herein, the continuous grouping of fibers may be processed into loose fibers, or may be kept in their state as a continuous grouping of fibers, or may be processed into yarns, or may be woven or knitted into fabric. It has been found that pretreatment of fiber in accordance with the embodiments of the present technology impart many advantages to the fiber.
In certain embodiments, the fibers may then undergo a dyeing process after the pretreatment processes as described herein. In other embodiments, they may be processed into yarn and then dyed; or woven or knitted into fabric and then dyed, or turned into the final consumer product and then dyed. Regardless of which stage the dyeing is performed, it has been found that the advantages due to the pretreatment remain in the fibers.
Various embodiments of the technology will be more fully described herein in the Examples.
EXAMPLE 1
Pretreatment Process—Inventive “Saturate/Store” Process
Baled cotton fiber is processed to produce a card lap or into a continuous grouping of fibers. The fiber is taken to an application machine where the fiber travels into a pad trough and comes into contact with a solution that contains:
1. about 1 to about 10 g/L Cottoclarin 88 ECO wetting agent;
2. about 10 to about 100 g/L caustic soda (NaOH);
3. about 10 to about 150 g/L “Catdye” CPHTAC;
The fiber is saturated in the pad trough and is extracted so that it retains a wet pickup of about 65 to about 150% of the pad solution. After extraction, the resulting fiber is sealed in storage containers. The containers are stored for about 8 to about 24 hours at room temperature, during which time the reaction between the solution and the fiber occurs.
After the storage time is complete, the fiber is removed from the containers and rinsed with an acid solution to lower the pH of the fiber to a range of about 4 to about 6.5. The fiber can then be extracted to a moisture content of below about 40% and dried in a heated oven. The dry fiber can be baled as loose fiber.
EXAMPLE 2 (COMPARATIVE EXAMPLE)
Pretreatment Process—“Exhaust” Process
The fiber is placed into stainless steel perforated carriers and placed into sealed vessels that can circulate a treating solution through the fiber. The solution contains:
1. about 3 to about 15 g/L wetting agent;
2. about 25 to about 100 g/L caustic soda (NaOH);
3. about 25 to about 150 g/L “Catdye” CPHTAC;
The amount of water contained in these vessels is about 5 to about 10 times the amount required for Example 1. The solution is heated to about 60 to about 90 degrees C. The solution is allowed to circulate for about 30 to about 90 minutes at that temperature. The solution is then drained and the fiber is washed with water at about 60 to about 80 degrees C. This rinse bath is drained and the vessel is now filled with colder water and enough acid to reduce the pH to below about 6.5. The fiber carriers are then taken from the vessels and the excess water is removed from the fiber. The fiber is then removed from the carrier, dried, and baled as loose fiber.
EXAMPLE 3 (COMPARATIVE EXAMPLE)
4% Dye Solution with a Conventional Reactive Dye Procedure (No Pretreatment)
A 20 gram sample of conventional, untreated cotton knit fabric was dyed as follows: the sample was prepared in an aqueous bath having a water volume of 10:1 containing 1 g/L of Amwet AFX (a nonionic wetting agent). The solution and fabric were heated to 80 degrees C. and circulated for 15 minutes to ensure complete wetting. This solution was drained.
A fresh aqueous bath having a water volume of 10:1 was prepared at 35 degrees C. with 4% Enverzol Navy ED (owg) (available from Everlight Chemicals USA) and added to the fabric. The fabric was agitated for 5 minutes and 80 g/L of NaSO 4 (sodium sulfate) was dissolved in the bath. 20 g/L of NaCO 3 (soda ash) was added to the dye bath. The dye bath was heated to 60 degrees C. and agitated for 45 minutes. The dye bath was drained and retained.
200 mL of fresh water was added to the fabric and agitated at 35 degrees C. for 10 minutes. This bath was drained and noted as 1st rinse.
200 mL of fresh water with 1 g/L citric acid was added to the fabric, and agitated at 70 degrees C. for 10 minutes. This bath was drained and noted as 2nd rinse.
200 mL of fresh water with 2 g/L soaping agent was added to the fabric, and agitated at 95 degrees C. for 10 minutes. This bath was drained and noted as 3rd rinse.
200 mL of fresh water was added to the fabric, and agitated at 60 degrees C. for 10 minutes. This bath was drained and noted as 4th rinse.
Four additional rinses were continued at 35 degrees C., each for 10 minutes until the bath was clear.
The amount of dye rinsed out, as well as the number of rinses required to obtain a clear bath, was noted and recorded as follows: the residual dye bath (amount of dye left after the dyeing was completed) and all rinse baths were evaluated using a spectrophotometer to determine transmittance values. Theses values provided indication of the amount of dye remaining in the fabric after each step and are listed in FIG. 3 . FIG. 4 is a graphical representation of the reduction of color with each step. As can be observed in FIG. 4 , it requires numerous rinses to remove the unfix dye from untreated cotton using the conventional reactive dye procedure. The conventional procedure also requires high temperature washes to improve the unfixed dye removal. Significant color reduction is not accomplished until after these hot washes. This can be noted in FIG. 4 as the line graph moves toward 100. The reduction in color with each step can visually be noted in FIG. 5 .
EXAMPLE 4 (COMPARATIVE EXAMPLE)
“No Chemical” Dyeing (4% Dye Solution) with Reactive Dye Using Pretreated Cotton (“Exhaust” Pretreatment Method)
A 20 gram sample of a cotton knit fabric made with yarn produced from fiber that was exhaust pretreated with a wetting agent (in accordance with a known pretreatment method) was obtained. The fabric was treated with a “no chemical” dye procedure as follows: the sample was added to an aqueous bath having a water volume of 10:1 containing 1 g/L of Amwet AFX (a nonionic wetting agent). The fabric was agitated for 5 minutes. To this aqueous bath that was prepared at 35 degrees C., 4% Enverzol Navy ED (owg) was added. The fabric was agitated in this dye bath while maintaining the temperature at 35 degrees C. for 30 minutes. The dye bath temperature was then increased to 80 degrees C. This temperature was maintained for an additional 15 minutes. After this time, the dyeing was completed and the dye bath was drained and retained.
200 mL of fresh water was added to the fabric, and agitated at 35 degrees C. for 10 minutes. This bath was drained and noted as 1st rinse.
200 mL of fresh water was added, and agitated at 70 degrees C. for 10 minutes. This bath was drained and noted as 2nd rinse.
Five additional rinses were continued at 35 degrees C., each for 10 minutes until the bath was clear.
It was observed that the fabric dyed using the exhaust pretreated fiber did not develop the same depth of color as the fabric dyed using the conventional reactive procedure (as used herein, “conventional reactive procedure” means dyeing of untreated fabric using chemicals (that is, not a “no chemical” dyeing procedure as described herein). This can be determined when comparing the reflectance information in FIG. 1 and FIG. 2 . The dyeing of the same percentage of Everzol Navy ED produces a shade considerably less. With the exhaust treated fabric in produced in Example 2, color can be obtained without the need of chemicals but not to the level of the conventional procedure shade in Example 3 with its required chemicals. This lower yield of color resulted in more residual dye left in the dye bath and requires numerous washes to try and remove. FIG. 6 and FIG. 7 confirm the color removal during washing. The lower yield and numerous washing were due to the low efficiency of the reaction of the exhaust ammonium salt application to the fiber. FIG. 8 shows the color reduction during the rinses and confirms that one less rinse is required and is accomplished with lower temperature. The dye was removed from the fabric easier and without the need of high temperature, but because of the higher residual dye it required numerous rinses.
EXAMPLE 5
“No Chemical” Dyeing (4% Dyeing Solution) with Reactive Dye Using Inventive Pretreated Cotton Procedure
Cotton knit fabric was made from yarn that was pretreated in accordance with an embodiment of the present technology (also referred to herein as the “saturate/store” technology). A 20 gram sample of the cotton knit fabric was added to an aqueous bath having a water volume of 10:1 containing 1 g/L of Amwet AFX (a nonionic wetting agent). The fabric was agitated for 5 minutes. To this aqueous bath that was prepared at 35 degrees C. was added 4% Enverzol Navy ED (owg). The fabric was agitated in this dye bath while maintaining the temperature at 35 degrees C. for 30 minutes. The dye bath temperature was then increased to 80 degrees C. This temperature was maintained for an additional 15 minutes. The dye bath was drained and retained.
200 mL of water was added to the fabric, and agitated at 35 degrees C. for 10 minutes. This bath was drained and noted as 1st rinse.
200 mL of fresh water was added and agitated at 35 degrees C. for 10 minutes. This bath was drained and noted as 2nd rinse.
One additional rinse was continued at 35 degrees C., for 10 minutes until the bath was clear.
It was observed that the fabric made from fiber pretreated with the inventive saturate/store application has a shade that was darker than the results of Example 3 and Example 4. This indicates that more color was exhausted for the dye bath than the conventional reactive procedure and the exhaust fiber application (i.e., more dye made it onto the fabric, and less dye was wasted). This was confirmed in comparing reflectance values in FIG. 1 and FIG. 2 . With more color exhausting onto the fabric, there is less residual dye left in the dye bath and less unfixed dye on the dyed fabric to be rinsed out. FIG. 9 and FIG. 10 confirm the lower dye bath level and that the necessity of only three rinses to produce a clear rinse bath. FIG. 11 confirms the need for only 3 rinses.
As can be seen, fewer rinses and higher dye exhaustion generates a significant water and time savings when compared to conventional reactive dyeing. This pretreated fabric using the “no chemical” dyeing produced a dark navy color equal or better than a conventional reactive procedure without the need of dyeing chemicals (salt and alkali) that are required to dye untreated cotton. Using fabric produced with the inventive saturate/store application cotton fiber, the required dye chemicals that cause pollution when discharged into the environment can now be eliminated. The shorter dye cycle (fewer rinses) and lower temperature requirement due to the high efficiency of pretreatment all contribute to significant energy savings for dyeing.
EXAMPLE 6
“No Chemical” Dyeing (3% Dyeing Solution) Using Inventive Pretreated Cotton Procedure
A 20 gram sample was obtained of a cotton fabric that was made with yarn produced from fiber pretreated in accordance with an embodiment of the inventive saturate/store technology described herein. This fabric was dyed using the “no chemical” dye procedure as follows: The fabric was added to an aqueous bath having a water volume of 10:1 containing 1 g/L of Amwet AFX (a nonionic wetting agent). The fabric was agitated for 5 minutes. To this aqueous bath that was prepared at 35 degrees C., 3% Enverzol Navy ED (owg) was added. The fabric was agitated in this dye bath while maintaining the temperature at 35 degrees C. for 30 minutes. The dye bath temperature was then increased to 80 degrees C. This temperature and agitation was maintained for an additional 15 minutes. After this time, the dyeing was completed and the dye bath was drained and retained.
200 mL of fresh water was added to the fabric, and agitated for 10 minutes at 35 degrees C. This bath was drained and noted as 1st rinse.
200 mL of fresh water was added and agitated at 35 degrees C. for 10 minutes. This bath was drained and noted as 2nd rinse. No additional rinses were needed because the resulting rinse bath was clear.
Since a darker shade was obtained with the dyeing in Example 5 than Example 3 (Comparative Example), it was concluded, as can be seen from FIG. 11 , that there was still some unfixed dye in the dye bath. For this reason, this Example 6 was prepared using the sample fabric and “no chemical” procedure as used in Example 5 and only reducing the Everzol Navy ED from 4% to 3% (owg). This is a 25% reduction in color from Example 3 to Example 5. The result of this dyeing was observed, as shown in FIG. 12 and FIG. 13 . FIG. 2 provides a graphic representation of the differences of each dyeing (conventional, exhaust pretreatment, inventive saturate/store pretreatment with 4% dye solution, inventive saturate/store pretreatment with 3% dye solution, and inventive saturate/store pretreatment with 2% dye solution.
As can be seen in FIG. 13 , results confirmed that the reduced level of dye resulted in more dye being exhausted form the dye bath and out of solution. Only two rinses were required to remove the color from the fabric. This was observed as shown in FIG. 14 .
EXAMPLE 7
“No Chemical” Dyeing (2% Dyeing Solution) Using Inventive Pretreated Cotton Procedure
A 20 gram sample was obtained of a cotton fabric that was made with yarn produced from fiber pretreated in accordance with an embodiment of the inventive “saturate/store” technology. This fabric was dyed using the “no chemical” dye procedure as follows: the fabric was added to an aqueous bath having a water volume of 10:1 containing 1 g/L of Amwet AFX (a nonionic wetting agent). The fabric was agitated for 5 minutes. To this aqueous bath that was prepared at 35 degrees C., 2% Enverzol Navy ED (owg) was added. The fabric was agitated in this dye bath while maintaining the temperature at 35 degrees C. for 30 minutes. The dye bath temperature was then increased to 80 degrees C. This temperature and agitation was maintained for an additional 15 minutes. After this time, the dyeing was completed and the dye bath was drained and retained. No additional rinses were required because the resulting dye bath was clear.
In order to determine if the dye bath could be completely cleared, this Example was prepared using cotton fabric that was made with yarn produced from fiber pretreated in accordance with an embodiment of the inventive saturate/store technology. This sample was dyed with the 2% Everzol Navy ED, representing a 50% reduction in dye from Example 1 and Example 3. FIG. 15 and FIG. 16 show the color remaining after dyeing. The dye was completely exhausted. This confirms that the embodiments herein are vastly superior to methods known in the art, in that they will allow for dyestuff to be removed from the dye bath and permit recycling of the water used in dyeing. FIG. 17 is a visual observation of this dye bath. As can be seen, the dye bath is visually clear, showing the optimal result desired.
FIG. 18 and FIG. 19 show a comparison of all parameters from among all of the dye baths used herein—that is, Example 3, Example 4, Example 5, Example 6, Example 7 and a bath containing the initial concentration of 4% Everzol Navy ED. Using the conventional reactive dyeing procedure on untreated cotton (Example 3) as the standard, the following difference in time, water, chemicals, and dye can be calculated:
With Example 4, there is a 99% savings on chemicals required. The amount of dye is the same though the depth color obtained is less. Since one less rinse was required to clear the bath, this represents only an 11% savings in water and a 24% time reduction.
Example 5 has the same 99% savings on chemicals but used the same level of dye and achieved a darker shade than Example 4. Only 3 rinses were required to clear the bath, representing a 56% savings in water and a 46% reduction in time.
Example 6 still represents a 99% chemical savings and adds a 25% dyestuff savings. Two rinses were required, generating a 67% water savings and resulting in a 56% time savings.
Example 7 demonstrates 50% dye reduction with the continuing 99% chemical savings. Because all the dye is exhausted during the dye cycle, there is a 90% savings of water and the savings in time is 62%.
It should be noted that the Examples above are merely illustrative, not limiting to the present technology, and that additional embodiments and variations are possible without departing from the spirit of the technology.
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The present technology is directed to devices and methods for dyeing a fiber, including pretreatment of the fiber before contacting it with a dye. The present technology is also directed to methods of improving the dyeability of a fiber, as well as increasing the efficiency of the dyeing process and minimizing waste and loss of dye.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application relates to subject matter disclosed in copending application Ser. No. 128,863 filed Mar. 10, 1980 now U.S. Pat. No. 4,335,431 and copending application Ser. No. 118,909 filed Feb. 6, 1980, now U.S. Pat. No. 4,321,677 issued Mar. 23, 1982.
FIELD OF THE INVENTION
This invention relates to a skid control method for controlling the pressure of braking oil when a vehicle slips during a vehicle braking operation and more particularly to such a method using a microcomputer.
BACKGROUND OF THE INVENTION
In skid control, the slip rate is calculated from the calculated wheel speed and when the calculated slip rate reaches a predetermined value, the brakes are released, while when the slip rate is restored to another preset value, the braking oil pressure is reapplied. The time during which the brakes are released is measured and the next instant of brake release is controlled on the basis of the result of the measurement. Repeating this series of operations thereafter, the frictional coefficient between the wheels and the road surface is kept at a maximum value so that the stopping distance is shortened.
The calculation of the wheel speed is one of the most important factors necessary for skid control as a whole and therefore must be processed exactly and swiftly.
To calculate the wheel speed from the signal delivered by the wheel speed sensor, there are two methods such as a proposed method in which pulses from the wheel speed sensor are counted for a predetermined constant time and a method in which the time interval between adjacent pulses is measured. The former method is not adapted for an anti-skid apparatus which requires rapid calculations, since this method needs to count pulses and therefore requires a certain time. The latter method, which measures the interval between adjacent pulses, can perform a rapid processing since only a time equal to the pulse-to-pulse period is required in this case. However, the measurement of only the pulse-to-pulse period results in a rather large error and therefore in practical applications it is necessary to measure several numbers of such periods and to figure out the average of them. Accordingly, it becomes difficult also in this case to complete the processing in a very short time.
The pulse-to-pulse periods are successively stored in a memory (RAM) and they are read out for processing in the case of the wheel speed being calculated. At the time of calculating the wheel speed, it is necessary to check which data block is to be used. According to methods currently adopted, the program for calculation is very complicated so that the number of locations in memory used for calculation processing is considerable.
SUMMARY OF THE INVENTION
An object of this invention is to provide a skid control apparatus which has a high speed of processing the calculation of the wheel speed and uses only a small number of memory locations for the calculation.
According to the features of this invention, the sampling timing for detecting the wheel speed is varied in accordance with the change in the wheel speed, the newest data representing the pulse-to-pulse period derived from the wheel speed sensor is stored in the head location of the memory, and the data is always subjected to rearrangement from the head location to the succeeding ones in memory according to the order of arrival.
Other objects, features and advantages of this invention will be apparent when one reads the following description of the embodiment of thie invention with the aid of the attached drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows a skid control system using a microcomputer, as an embodiment of this invention;
FIG. 2 shows in detail the principal part of the skid control system shown in FIG. 1;
FIGS. 3 and 4 show flow charts for explaining the operation of the skid control system shown in FIG. 1 or 2;
FIG. 5 shows in graphical representation the relationship among the vehicle speed, the virtual vehicle speed, the wheel speed and the operation of the actuator for controlling the brake oil pressure, at the time of panic braking;
FIGS. 6 shows the relationship between the brake releasing period and the slip rate S;
FIG. 7 is a block diagram useful in explaining the functions of the free-running counter, the register and the register control circuit;
FIGS. 8A and 8B are diagrams useful in explaining the operation of the free-running counter;
FIG. 9 illustrates how to obtain the period of the wheel speed pulses;
FIG. 10 illustrates how to obtain the pulse duration or width of the wheel speed pulses;
FIG. 11 is a flow chart for the processing of taking in the content of the free-running counter to the specific memory according to this invention;
FIGS. 12 to 15 illustrate how to store data in RAMS;
FIG. 16 is a flow chart for the process of calculating the wheel speed;
FIG. 17 shows the waveforms of the wheel speed signal and the IRQ signal according to this invention; and
FIG. 18 is a flow chart associated with the signals shown in FIG. 17.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 schematically shows a skid control systemm using a microcomputer (hereafter referred to as CPU), as an embodiment of this invention. The mechanical power generated by an engine (not shown) is transmitted through a transmission gear assembly (not shown) and a propeller shaft 13 to a differential gear 15, which in turn drives rear wheels 17. The output signals of a wheel speed sensor 19 attached to the propeller shaft 13 are sent through a signal line 21 to a control apparatus 11. The control apparatus incorporates therein a CPU and an I/O circuit (i.e. input/output circuit). A detailed description thereof will be given later. An actuator 23 has a solenoid 25 energized by an output signal sent from the control apparatus 11 through a signal line 27. The diaphragm chamber in the actuator 23 communicates with the engine manifold having a negative pressure through a pipe 29 and with the surrounding atmosphere through an air filter 31 and pipe 33. The diaphragm of the diaphragm chamber is coupled to a piston rod. The force generated by depressing a brake pedal 35 is converted to an oil pressure by means of a master cylinder 37. The induced oil pressure is transmitted to an oil pressure control valve 39. The oil pressure discharged from the oil pressure control valve 39 is used, through a pipe 41, to brake front wheels 43 and also transmitted to the actuator through a pipe 45. The pressured oil whose pressure was controlled by the piston rod in the actuator 23, is used, through a pipe 47, to brake the rear wheels 17. The control apparatus 11 and the negative voltage terminal of the actuator 23 are connected together through a conductor line 49, to have the same potential. The control apparatus 11 also has a warning lamp 51 connected therewith for warning of a malfunction of the system. A fuse 53 is inserted between the control apparatus 11 and a power source 56, the fuse 53 serving to cut the supply of power to the control apparatus to establish the normal braking condition when an abnormality occurs. When an ignition key switch 55 is turned on, electric power is supplied from the power source 56 to the control apparatus 11 through the fuse 53.
At the time of the brake being applied, if the solenoid 25 is turned on, the piston rod coupled to the diaphragm in the actuator 23 is shifted so that the oil pressure decreases to release the braking force.
FIG. 2 shows in detail the circuit of the control apparatus 11 shown in FIG. 1. The positive voltage terminal 111 of the control apparatus 11 is connected with the positive electrode of the power source and therefore a voltage V B is supplied to the control apparatus 11. The power source voltage V B is kept constant, for example, at +5 V, by means of a voltage regulating circuit 113. This constant voltage V cc of, for example, +5 V is applied to a CPU 135. The CPU 135 includes therein a MPU (Microprocesser) 115, a RAM (Random Access Memory) 117, a ROM (Read-Only Memory) 119, register control circuits 131 and 133, free-running counters 123 and 125, and registers 127 and 129. The constant voltage V cc is also supplied to an I/O (input/output) circuit 121. The microcomputer unit, MC6801, sold by Motorola Inc. is known as incorporating a free-running counter therein.
The wheel speed sensor 19 converts the rotational speed of a rotor 136 to a corresponding AC voltage by its electromagnetic pickup 137. The output of the pickup 137, i.e. the signal representing the rotational speed of the rotor 136, is supplied through a waveform shaping circuit 139 to the I/O circuit 121. The outputs of the I/O circuit 121 are supplied through amplifiers 141, 143 and 145 to the fuse 53, the warning lamp 51 and the solenoid 25.
The MPU 115, the RAM 117, the ROM 119, the registers 127 and 129, and the I/O circuit 121 are interconnected with one another through data bus, address bus and control bus 147 (all the buses are indicated by reference numeral 147). A clock signal E is sent from the MPU 115 to the RAM 117, the ROM 119, the free-running counters 123 and 125, and the I/O circuit 121, whereby the data transmission is performed in synchronism with this clock signal E. The free-running counters 123 and 125 count the pulses of the clock signal E. When the count value overflows the counters 123 and 125, they send an overflow signal to the register control circuits 131 and 133 respectively so that the counters 123 and 125 are reset to their initial states and resume counting, repeating these cycles. The register control circuit 131 and 133 control the timing when to store the contents of the free-running counters 123 and 125 in the registers 127 and 129 respectively.
Now, description will be given of the operation of the skid control system as an embodiment of this invention.
If a rolling body, e.g. a vehicle, moving at a speed of V in a certain direction on a plane, slips, then the associated slip rate S is defined such that ##EQU1## where R is the radius of the rolling body and ω is the angular velocity of the rolling body. Here, it is to be noted that the frictional coefficient μ, defined between the tire of the vehicle and the road surface bearing the tire thereon, is a function of the slip rate S. According to experiments, it has been determined that the frictional coefficient μ takes a maximum value in the direction of forward movement when the slip rate is near 20%, while μ decreases with the increase in S in the case of lateral slipping. Accordingly, if the slip rate S is controlled to be near 20%, the frictional coefficient μ between the tire and the road surface could be made maximum when the car skids. The skid control apparatus according to this invention controls the slip rate S in such a manner that S is near 20% in the case of skidding.
FIGS. 3 and 4 show a flow chart for explaining the operation of the control system according to this invention. As shown in FIG. 3, in step 05, the register group is initialized and simultaneously the polarity of a trigger signal for storing the contents of the free-running counters into the registers is specified. In step 10, a self-check of the control circuits, especially the functions of the memories and the I/O circuit, is performed. The MPU generates specific patterns and if a signal corresponding to the patterns is received, the check is determined to be OK in step 15. When an abnormal condition is found by the self-check, the abnormality is indicated by the warning lamp 15 (step 20). In this case the self-checks are performed a predetermined number of times in step 25. If the abnormal condition still remains after all the self-checks have been made, a warning lamp will be turned on and the operation is stopped in step 30. In this case, the normal braking operation is performed, but the skid control is not put into operation.
When the self-check is O.K. in the step 15, the brake control operation moves to step 35. In the step 35, stored data is read out and a subtracting calculation operation between the registers yields the wheel speed. In step 37, whether the solenoid of the actuator is energized or not is checked. Initially, the solenoid is deenergized or off. In step 40, whether panic braking is applied or not is checked on the basis of the variation of the wheel speed. Namely, if the decrease in the wheel speed exceeds a preset value, panic braking is identified. This point is explained with the aid of FIG. 5. FIG. 5 shows the relationship among vehicle speed, virtual vehicle speed, wheel speed and the decrease (ON) and increase (OFF) in the brake oil pressure, in the case where the brake oil pressure is so controlled as to cause the frictional coefficient between the wheel and the road surface to be maximum when panic braking is applied. Now, assume that a vehicle is moving at a speed V S . If the vehicle is suddenly braked under this condition, the wheel speed is decreased along curve A as shown in FIG. 5.
Turning again to FIG. 3, if there is no panic braking, the step 35 is again reached to calculate the wheel speed. At the time of normal operation (driving without panic braking), a closed loop of the steps 35 to 40 is repeatedly executed. When panic braking is detected in the step 40, step 45 is reached. In the step 45, the virtual vehicle speed is derived from the calculated wheel speed.
Here, the virtual vehicle speed should be exactly defined. In the expression for the skid rate S, V is defined as the speed of the rolling body (this corresponds to the vehicle speed). Therefore, the vehicle speed must be calculated to obtain the slip or skid rate S. Since a vehicle is stopped by braking its four wheels, it is impossible to obtain the real vehicle speed directly. Accordingly, the virtual vehicle speed to give the measure of the actual vehicle speed must be obtained to be used and defined as one of the controlling items. In general the virtual vehicle speed is assumed to have a gradient of -1.4--1.7 g (gravity acceleration) and the slip rate S given by the above expression (1) is calculated under this assumption. In FIG. 5, broken curve B represents the virtual vehicle speed, which decreases at the above mentioned gradient at the deceleration starting point 1 . On the basis of the comparison between the wheel speed calculated in the step 35 and the virtual vehicle speed calculated in the step 45, whether the predetermined ON slip rate is reached or not is checked in step 50 in FIG. 4, the ON slip rate being the one for which the solenoid of the actuator is to be turned on. When the predetermined ON slip rate is detected in the step 50, that is, when the point 3 in FIG. 5 is reached, a brake releasing signal is generated in step 55. The ON slip rate at the point 3 is preferably equal to 0.5, as required by empirical factors. The brake releasing signal is stored in the memory in step 56. After the brake releasing signal has been delivered, the control operation is returned to the step 35 in FIG. 3. Since the actuator is turned on in step 37, step 58 in FIG. 4 is then executed. In the step 58, whether the slip rate is equal to the predetermined OFF slip rate or not is checked on the basis of a comparison between the wheel speed and the virtual vehicle speed, the predetermined OFF slip rate being the factor which leads the solenoid of the actuator to be deenergized or OFF. The predetermined OFF slip rate is always kept constant at, for example, 0.2 at the point 7 as well as the point 5 in FIG. 5. If the actual slip rate is below the predetermined OFF slip rate, that is, it corresponds to the point 4 in FIG. 5, then the control operation is returned to the step 35. When the predetermined OFF slip rate is reached, that is, any point after the point 5 in FIG. 5 is reached, step 60 is executed. In the step 60, unless the actuator is being energized, the step 35 is resumed, while if the actuator is being energized the step 65 is executed. In the step 65, the brake releasing signal is interrupted and in step 70 the ON time (the period for which the brake releasing signal lasts) is measured. In step 75, the predetermined ON slip rate necessary for the next control, i.e. the slip rate corresponding to the point 6 in FIG. 5, is taken from the memory on the basis of the ON time measured in the step 70 and the value taken is then stored in the specified memory. The control operation is then transferred to step 35. The ON time for which the brake releasing signal lasts, varies depending on the magnitude of the frictional coefficient.
Moreover, the virtual vehicle speed is assumed to have a gradient of -1 g and the timing at which the second and succeeding brake releasing signals are delivered is changed, to correct the virtual vehicle speed, depending on the ON time t ON obtained in the immediately previous control cycle. Namely, the slip rare required in the second or succeeding control is a function of the ON time t ON .
FIG. 6 shows the relationship between the ON time t ON and the predetermined ON slip rate S. It is assumed that the n-th brake releasing signal lasts for a period t ON (n) as shown in FIG. 6. Then, the predetermined ON slip rate S for determining the timing at which the (n+1)th brake releasing signal is delivered is calculated to be S n . Thereafter, similar operations are repeated until the wheels stop. Since it is difficult to express the relationship shown in FIG. 6 by an equation, it is stored in the memory with discrete sampling values at specific intervals, e.g. every 10 mS. It is therefore possible that if the ON time t ON (n) is measured, S n is immediately obtained. The points 3 and 6 in FIG. 6 correspond to the points 3 and 6 in FIG. 5.
FIG. 7 is a diagram for explaining the operations of the free-running counters 123 and 125, the registers 127 and 129, and the register control circuits 131 and 133. A reference clock signal E generated by the MPU 115 is sent to the free-running counter 123 (hereafter only one of the equivalent members is mentioned for simplicity). The free-running counter 123 counts up or down in synchronism with the clock signal E, starting at the count value specified by the initialization cycle as shown in FIG. 8A or 8B, irrespective of the operation of the MPU 115. According to the mode shown in FIG. 8A, the counter 123 counts up, starting from the value $00 set through the initialization, and when the content of the counter 123 becomes equal to $FF, the count value is reduced to $00 in response to the next coming clock signal E. Thereafter, the above operation is repeated. On the other hand, according to the mode shown in FIG. 8B, the counter 123 counts down from the value $FF set through the initialization and when the count value reaches $00, it jumps up to $FF in response to the next clock signal E, being prepared again for counting down. Either of the modes can be selected depending on the method of control required.
The MPU 115 sends to the register control circuit 131 an instruction to cause the circuit 131 to send a trigger signal to the register 127 in response to the leading or trailing edge of the input signal, e.g. WSP (wheel speed pulse). In response to the trigger signal, the register 127 takes in and stores therein the content of the free-running counter 123, reached when the trigger signal is generated. The register 127 is, for example, of 16-bit structure.
FIG. 9 illustrates a technique for obtaining the period of the WSP (wheel speed pulse) signal. Software controls the delivery of the trigger signal in response to the leading edge or the trailing edge to take in the wheel speed. In FIG. 9, it is assumed that the trigger signal is delivered in response to the leading edge of the WSP according to the program. This instruction for triggering is effected through the software and the register control circuit 131 shown in FIG. 7 which holds the old instruction unless this instruction is sent to the circuit 131 to rewrite its content. When a signal indicating the leading edge of the WSP is received, the count value at that instant of the free-running counter 123 is stored in the Q register 151 of the register 127 shown in FIG. 7. When a signal indicating the leading edge of the next WSP or the n-th (n<10) following WSP in the case of a high wheel speed is received, the count value of the free-running counter at that instant is stored in the P register 149 of the register 127 shown in FIG. 7. The operation of storing the contents of the free-running counter into the P and Q registers is performed by the event transition of the WSP, that is, the interrupt operation is performed in response to the WSP signal and the count values are stored through the interrupt processing. The time required for storing each content is 4-5 μsec. so that the storing operation by the P and Q registers is finished in about 9 μsec. According to this method described above, the duration or width of a pulse of a pulse signal having a long repetition period can be measured for about 9 μsec. Accordingly, the requirement according to the conventional measuring method that the MPU must be exculsively used over the duration of a pulse in the measurement of the pulse width can now be eliminated. Therefore, each of the times required for various processings necessary for the skid control now in question can be shortened.
When the P and Q registers finish storing the contents of the free-running counter, the software generates an instruction to cause the P and Q registers to make a subtracting operation between them. The result of the subtraction is stored in, for example, an S register 153 of the register 127. If the subtraction causes a carry signal, the subtraction is done in consideration of the carry signal. The wheel speed is obtained from the above result. In some cases, it may be difficult due to the mechanical structure of the wheel speed sensor to obtain uniform WSPs and therefore the I/O circuit may receive a signal having various duty cycles from the sensor. In such cases, if the wheel speed is determined by measuring the duration of a single pulse, a large error may be introduced depending on the instant of sampling, degrading the accuracy in measurement. To make the error in measurement minimum, the pulse widths W1, W2, W3, . . . etc. of several wheel speed pulses are measured as shown in FIG. 10 and the average W of them is calculated. By using the calculated average W as the wheel speed data for the succeeding calculation, the deviation of the output of the wheel speed sensor can be compensated to a great extent.
In the case of low wheel speed, the state of the wheel being at low speed should be checked in the step 35 in FIG. 3 and signals in synchronism with the leading and trailing edges of a wheel speed pulse can be used as trigger signals. Accordingly, it is possible to obtain sufficient wheel speed data even during low speed drive by measuring the wheel speed data every half a cycle which data has hitherto been measured every cycle.
According to this invention, the newest data is stored always in the location of the RAM with the address No. 1 and the next newest data in the location of address No. 2 and so on, and all the data are stored in order of arrival at the RAM so that the program for the calculation of the wheel speed can be easily executed.
FIG. 11 is a flow chart illustrating the process of loading the content of the free-running counter into the memory according to this invention.
The start step 20 is followed by step 21 where a check is made of whether a pulse is received or not. If a pulse is received, an interruption for a processing operation takes place in step 22. In the step 22, each data location in the RAM is shifted down by one location, that is, the content of the address No. 8 is transferred to the address No. 9, the content of the address No. 7 to the address No. 8, etc. After the content of the addres No. 1 has been transferred to the location of address No. 2, the content, or count value, of the free-running counter is read in step 23, and stored in the location of address No. 1. This process is shown in FIGS. 12 to 15. FIG. 13 shows the state of the data being stored in the RAM when the pulse WSP9 is received. The newest data T9 is stored in the address No. 1 and the successive addresses of the RAM are occupied by the data blocks in order of the arrival. FIG. 14 shows the state of the data blocks being stored in the RAM when the pulse WSP10 is received. FIG. 15 shows the state of the data blocks being stored in the RAM when the pulse WSP12 is received. In both the states, the newest data is held in the address No. 1 and the following addresses are occupied by the data blocks arranged in order of the arrival. With this arrangement of data blocks, the difference between the data blocks stored in the addresses Nos. 1 and 2 may be obtained to calculate the pulse-to-pulse period, the difference between the data blocks in the addresses Nos. 1 and 9 to calculate eight times the period, the difference between those in Nos. 1 and 5 for four times the period, and the difference between those in Nos. 1 and 3 for twice the period. These periods have constant values and since it is unnecessary to check in each operation which addresses in the RAM are to be selected to provide data, the associated program and the resultant processing time can be both shortened.
The above described process is shown in flow chart in FIG. 16. The processing is started with step 24, and the difference between the data blocks in the addresses Nos. 1 and 2 is calculated to obtain the pulse-to-pulse period in step 25. The difference, assumed to equal T, is compared with a reference value t o in step 26. If T is smaller than t o , the difference between the data blocks in the addresses Nos. 1 and 9 is calculated in step 27 to obtain 8 times the pulse-to-pulse period. By dividing the resultant period by 8, the average pulse-to-pulse period is obtained with a reduced error. In step 28, whether t o <T<2t o or not is checked. If the condition that t o <T<2t o is satisfied, the difference between the data blocks in the addresses Nos. 1 and 5 is calculated in step 29 to obtain 4 times the pulse-to-pulse period. The obtained period is then divided by 4 to provide an average. In step 30, whether 2t o <T<4t o or not is checked and if the in equality is satisfied, the data difference is calculated between the addresses Nos. 1 and 3 in step 31 to obtain twice the pulse-to-pulse period. Then, to calculate an average, the thus obtained period is divided by two. When T>4t o , the data difference is calculated between the addresses Nos. 1 and 2 to obtain only the pulse-to-pulse period.
As described above, by storing the newest data in the head location of the memory and also by occupying the succeeding locations of the memory by the data in order of the arrival, the calculation of the wheel speed can be processed in a short time with a high precision and the number of the steps of the program and therefore the capacity of the memory can be reduced, whereby an excellent anti-skid control apparatus can be provided.
FIG. 17 shows the state where the sampling timing for detecting the wheel speed is varied when the wheel speed exceeds a certain value. At points Y and X, the content of the free-running counter is stored in the register and at point A after a time t A the pulse-to-pulse interval PW n is determined to calculate the wheel speed. During a time t B (between points A and B) the calculation results based on PW n is put up, and the IRQ signal, if it is received and the task has not yet been finished, is masked. The interrupt flag is cleared so as to accept the IRQ signal when the processing operation returns again to the starting step of the main routine after the end of the processing of the above task. By doing this, the task processing operation in the main routine is prevented from being retarded by the interrupt processing in response to the IRQ signal so that a normal processing operation is possible.
FIG. 18 shows a flow chart of a program for an embodiment of this invention. FIG. 18 is a detailed version of the step 35 shown in FIG. 3, with an instruction for clearing the IRQ mask bit applied to the connector 1/2 shown in FIG. 4. In FIG. 18, the content of the free-running counter that has been stored in a specified memory in response to the IRQ signal is read out in step 100 and the read out contents of the free-running counter are subjected to subtraction to obtain the pulse width PW for the wheel speed signal in step 105. In step 110, the thus obtained pulse width PW is compared with a predetermined pulse width PW o . If PW<PW o , the pulse width is calculated in step 125 and the IRQ mask bit is set in step 130. If PW≧PW o , the steps 37-45 in FIG. 3 and the steps 50-75 in FIG. 4 are executed and after the execution of these steps the IRQ mask bit is cleared in step 120 and again the step 100 is reached.
A still faster processing operation would be required in the case of a high speed wheel rotation where the next wheel speed pulse is received while the processing routine (step 115) using the pulse width (i.e. wheel speed difference) obtained through the calculation in the step 125 is under execution. In such a case, to mask the IRQ signal as described above, the IRQ mask bit is set to mask several pulses and an interruption is prevented to increase the speed of processing by clearing the IRQ mask bit at the time when the arithmetic processing routine (step 115) is finished.
In FIG. 18, if the pulse width PW becomes smaller than the predetermined pulse width PW o , the step 130 is executed to set the IRQ mask bit. Accordingly, unless the IRQ mask bit is cleared in the step 120 after the execution of the step 115, the IRQ signal for detecting the wheel speed will be ignored even if it is received while the step 115 is under execution in the main program. After the execution of the step 120, the IRQ signal for detecting the wheel speed is accepted to resume the detection of the wheel speed.
If the wheel speed is lowered to cause the pulse width to be greater than T o , the wheel speed data is stored in the data addresses in the RAM to execute normal control processing, i.e. tasks such as the check of skid state, the delivery of the brake releasing signal, the release of braking, and the measurement of ON TIME.
As described above, by making variable the sampling timing for detecting the wheel speed through the control of software and by detecting the wheel speed at the time of high speed rotation by the use of the variable sampling timing, the MPU can be prevented from being occupied for the purpose of detecting the wheel speed so that the above task is prevented from being retarded.
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A skid control device employs a wheel speed sensor and the control circuit which includes a microcomputer. The microcomputer computes wheel speed on the basis of a pulse signal derived from the wheel speed sensor and delivers a break releasing signal when the wheels slip. A brake control apparatus for controlling the pressure of oil for applying the brakes to the wheels responds to the outputs of the microcomputer. The microcomputer contains a free-running counter which counts clock pulses and a memory containing a sequence of storage locations. This sequence of storage locations stores count values of the free-running counter. A pulse signal from the wheel speed sensor is employed to produce an interrupt request for the microcomputer. The contents of successively adjacent locations in memory are employed by the microcomputer for carrying out the necessary calculations and computing wheel speed.
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FIELD OF THE INVENTION
The present invention relates to support structures which depend from containers and more particularly to a structure which depends from product containers relating to the toiletries industry and which can support lightweight structures.
BACKGROUND OF THE INVENTION
Safety razors and similar structures have evolved from a heavy metal blade holder to a light weight plastic disposable structure. The heavy metal blade structures provided for a disposable blade. When the blade became dull because it was wet or worn, the only portion which was disposed of was the thin metal portion. With the one piece plastic disposable structures presently provided, a worn or corroded blade results in the whole unit being disposed. In presently used structures, one or two blade edges may be present and they can quickly corrode if left laying in a down position in water and especially in a soap dish.
To extend the time of usage of the disposable by 7 to 10 days would not only be of economic advantage to the user, but would also slow the stream of disposable razors headed toward the refuse collection system. In addition, any structure which adequately supported a disposable razor would contribute to the tidiness of the bathroom areas since disposables are normally placed flat on the counter. Flat placement is normally with the blades facing down, which contributes to their corrosion and short life, for both metal and plastic disposable razors. Further, when razors are left lying about, they form an extreme hazard for children who are easily cut just by coming into contact with the razors.
Another problem with disposable blades is packaging. They do not stack well and are generally packaged densely in a soft pack. It is difficult to provide a single razor with, for example, a can of shaving cream without the use of shrink wrap packaging. This is difficult to achieve by machine since the razor may not always be positioned properly on the can. Further, since the blade area may be pressed against the can, a bump or other side impact can bend and ruin the blades. Where the razor is facing away from the can during shrink wrap, it may be further damaged by other forces from the outside.
What is therefore needed is a support which may be used in packaging which will support a razor proximate to a can in a position where the razor will not be damaged. Further, and in order to conserve resources, the needed support should be amenable to further permanent use to support later acquired disposable razors for the user. Further, and to avoid confusion the support should accommodate a single razor so that the user will continue to use a single razor until it is worn enough to be replaced by another new razor. In this manner a significant savings would result in the case of a user who continually opens new razors only to leave them exposed in a wet environment to corrode. The support will also contribute to the lengthening of the life of permanent metal razors having disposable blades, or metal razors having plastic disposable blade cartridges.
Another problem within the environment of disposable razors and shaving cream cans is that of rust at the bottom of the can. Although most cans have a generous coating of lacquer or enamel, being left in a wet environment over time can cause rusting of the bottom rim and exposure of the raw metal can. Although the can will be discarded after use, rust from the bottom of the can will discolor surfaces on which it is placed, including enamel sinks and enamel finish medicine cabinets. Generally damage from this rust discoloration can be prevented only by providing a specialized surface on which the can will be stored. What is needed is a razor support structure which can both support and collect a shaving can and razor and will also prevent rust discoloration.
The razor support structures needed may be of several types and may be able to provide support in a variety of circumstances. Various supports should encompass a variety of support opportunities. The needed supports should be able to engage round objects, flat surfaces, and the tops of cans. The needed supports should either enable a disposable razor to continue to utilize the blade guard which was supplied with the razor, or should eliminate the need for the guard by providing a protective enclosure for the head of the razor.
SUMMARY OF THE INVENTION
Several embodiments of a disposable razor support structure include structures from which support is derived including (1) a support structure in the shape of a special clip for encircling and grasping the major portion of a can and which also grasps the disposable razor just below the head portion; (2) a cap support which engages a can in a manner identical to that of the way in which a cap engages the can; (3) a cap which engages a can; and (4) a magnetic attachment member which can adhere to either a can or other metal surface; (5) a horizontal can tray which can accommodate a can; and also structures for supporting a disposable razor including (1) a clip support structure in the shape of an Ω which grasps the upper handle of a razor, and (2) a trough to gently support the head of the razor, either of which can draw support from any of the structures described above.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which:
FIG. 1A illustrates a perspective view of a first embodiment of the invention having an enlarged clip for engaging a can of shaving cream or the like and a smaller clip for engaging the upper portion of the handle of a razor;
FIG. 2 illustrates a top view of the support shown in FIG. 1;
FIG. 3 is a closeup view of a co-planar version of the support of the invention shown in FIGS. 1 and 2;
FIG. 4 is a version of the support of the invention wherein the portion of the clip which engages the razor lies in a plane above the plane of the portion of the clip which engages the can;
FIG. 5 illustrates a second embodiment where the clip for holding the upper portion of the handle of a razor extends from a cap engageable with the top of a can;
FIG. 6 illustrates a variation of the second embodiment wherein the smaller clip is carried high up on the cap;
FIG. 7 illustrates a third embodiment illustrates a third embodiment in which the clip for holding the upper portion of the handle of a razor extends from a ring engageable with the top of a can identical to the manner in which a cap engages a can, but where the ring has an upper portion further engageable with a conventional cap, to enable the can to be secured with the cap whether or not the ring is in place;
FIG. 8 is a side view of a can of shaving cream with the ring of FIG. 7, and with a broken away view from one side of the can leading to the cap;
FIG. 9 is a closeup partially sectional view of the ring and cap shown in FIGS. 7 and 8 and illustrating the separate interlockability of the ring, can and cap;
FIG. 10 is a top view of the ring shown in FIGS. 8-11;
FIG. 11 illustrates a fourth embodiment which includes a small height base and support pole which extends from a shallow pan which is used to both support and insulate the bottom of the can from any contact with a surface in which discoloring rust might escape from the can;
FIG. 12 is an end view illustrating details of the support post of the fourth embodiment of FIG. 12;
FIG. 13 is a top view of the fourth embodiment of FIGS. 11 & 12;
FIG. 14 is a fifth embodiment includes a full length cup, within which a shaving cream can may sit and which is a full length cup which not only insulates the can from any surface, but which is also a washable cup which may be used to assist in brushing the teeth and the like;
FIG. 15 illustrates a top view of the fifth embodiment as shown in FIG. 14;
FIG. 16 illustrates a perspective view of a sixth embodiment which includes a full holder for gravity support of the razor which enables elimination of the razor guard since the razor head is cupped in its holder which has a trough with a pair of closed ends;
FIG. 17 is a side end view of the sixth embodiment of FIG. 16;
FIG. 18 is a top view of the sixth embodiment of FIGS. 17 and 18;
FIG. 19 is front view of the trough portion of the sixth embodiment;
FIG. 20 illustrates a perspective view of a seventh embodiment which includes a small clip displaced from the bottom of the trough structure shown in FIGS. 16-19, and which enables the head of a razor to be placed in the trough with its handled is swung down into place to be engaged by the clip;
FIG. 21 is a side sectional view of the seventh embodiment of FIG. 20;
FIG. 22 is a top view of the seventh embodiment shown in FIGS. 20 and 21;
FIG. 23 is a front view of the trough and below trough clip portion of the seventh embodiment of FIGS. 20-23;
FIG. 24 is a perspective view of an ninth embodiment having a trough structure connected to a combination suction cup and magnet stabilization structure;
FIG. 25 is a rear view of a variation on the eighth version of FIG. 24 and similar to FIGS. 20-23 in which a clip is mounted below the trough structure to stabilize the razor;
FIG. 26 is a rear view of the embodiment of FIG. 24;
FIG. 27 is an eighth embodiment of the invention and illustrating a small clip supported by a trough structure connected to a combination suction cup and magnet stabilization structure with magnet;
FIG. 28 is a sectional view taken along line 28--28 of FIG. 27, and illustrating the placement of the magnet at the center of the suction cup magnet stabilization structure; and
FIG. 29 is a rear view of the ninth embodiment shown in FIGS. 27-29 and showing the exposed end of the magnet.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The description and operation of the invention will be best described with reference to FIG. 1. FIG. 1 illustrates a conventional can 31 having a conventional cap 33. Typically the can 31 will be a can of pressurized shaving cream or shaving gel, since this type product is closely associated with shaving, although a can 31 of deodorant or the like, or any other can 31 is acceptable.
A support structure 35 of the present invention as shown in FIG. 1 includes a large clip portion 37 which partially encircles the can 31. The large clip portion 37 is attached to a small clip portion 39 which grasps a razor 41. Razor 41 can be any razor, but may especially be a disposable razor.
Referring to FIG. 2, a top view of the support structure 35 illustrates several options which are available. The large clip portion 37 has a pair of gripper inserts 43. The gripper inserts 43 may be attached to the inside of the large clip portion 37, or they may be inserted through the large clip portion 37 and extend outside the large clip portion. Exterior oriented gripper portions 45 may be integral with the gripper portions 43 or independent. The exterior gripper portions 45 does help in grasping the integrated unit shown in FIG. 1. Gripper portions 43 and 45 may also be neoprene pads.
The small clip portion 39 has a pair of end portions 47 which extend away from each other and which act to help open partially the small clip portion as a handle of the razor is laterally moved into the small clip portion.
Referring to FIG. 3, a variation in the support structure 35 is shown as including an upwardly extending brace portion 49 which will enable the support structure 35 to be grasped and lifted to take the can 31 with it. This brace 49 strengthens the support structure 35 and reduces the bending moment experienced at the end of the support structure 35.
Referring to FIG. 4, a further variation of the first embodiment of the support structure 35 is shown in which the small clip portion 39 lies in a first plane above the large clip portion 37 which lies in a second plane. A mere reversal of the support structure 35 would place the small clip 39 below the plane of the large clip 37.
Referring to FIG. 5, a second embodiment of the present invention is shown as a cap support 51 having a cap portion 53 and a small clip portion 55 formed integrally with the cap portion 53. Again, the razor 41 is shown as supported by the small clip portion 55. The distance of the small clip portion 55 from the cap portion 53 can be varied to accommodate a razor 41 having a greater or lesser angular displacement of the blade head.
Referring to FIG. 6, a different version of the cap portion 53 is shown where the small clip portion 55 extends from the cap portion 53 at a point higher up on the cap portion 53. This enables the space above the cap portion 53 to be accessed by the head portion of the razor 41. This configuration is especially useful where space exists above the cap portion and the razor 41 is packaged with the cap support 51.
FIG. 7 illustrates a third embodiment which includes a conventional cap 33 and a support structure 61 having an intermediate interlocking ring portion 63 and a small clip portion 65. The interlocking ring portion 63 has a lower surface which is equivalent to the bottom of the conventional cap 33 it replaces. The version shown will include a cap 33 having an abbreviated outwardly directed rim. Referring to FIG. 8, a semi sectional view of the ring of FIG. 7 shows how the intermediate interlocking ring portion 63 rests atop the can 31.
Referring to FIG. 9, a full exploded cross section illustrates the components of the third embodiment. Cap 33 has an abbreviated lower, outwardly disposed rim 67. The interlocking ring portion 63 is shown as having an upper, inwardly directed groove 69 which will accommodate the rim 67 to enable the cap 33 to lock onto the ring portion 63. The lower edge of the ring portion 63 has an outwardly disposed rim 71 which is the same size and shape as the outwardly disposed rim 67 of the cap 33. In this configuration, the system including the cap 33, support structure 61, and can 31, can be configured to include or exclude the support structure 61. Fully made up, the support structure 61 sits atop the can 31, and the cap sits atop the support structure 61, with all three of these structures being interlocked. Once the support structure 61 is removed, the cap 33 can be locked directly onto the can 31.
Referring to FIG. 10, a top view of the support structure 61 is shown. As can be seen, the structure overlying the inwardly directed groove 69 is seen as continuously extending about the support structure 61. The small clip 65 can be seen as extending from the ring portion 63.
Referring to FIG. 11, a fourth embodiment illustrates the conventional can 31 supported within a support structure 81 having a cylindrical portion 83 having a closed end 85 and a rim 87 which rises into a vertical support portion 89 which supports a small clip 91. The lower portion of the vertical support portion 89 is relatively wide to withstand pulling motion imposed on the small clip 91 when the razor 41 is being pulled away from the small clip 91.
Referring to FIG. 12, a profile of the vertical support portion 89 is better seen. Referring to FIG. 13, a top view looking down into the support structure 81 better illustrates the closed end 85 and, along with FIGS. 11 and 12, gives a more complete look at the entire structure.
Referring to FIG. 14, a fifth embodiment as a cup shaped support structure 93 has a small clip portion 95 supporting razor 41, and a lower closed end 97. As can be seen, a conventional can 31 is supported within the cup shaped support structure 93 and is thus further protected. The cup shaped support structure also insulates the bottom of the can 31 from any surface on which the cup shaped support structure 93 sits. In addition, the cup shaped support structure 93 doubles as a drinking cup, which is advantageous for brushing teeth, camping and other situations where a cup might be needed. FIG. 15 illustrates a top view of support structure 93 and the closed end 97 can clearly be seen.
Referring to FIG. 16, a sixth embodiment has a specialized structure for supporting the razor 41 by its head portion. A support structure 101 includes a large clip portion 103, and a trough portion 105. The trough portion 105 has a pair of end portions 107 which lend stability, but are not otherwise required. The trough portion 105 reveals a slot 109 which extends through an outer, tilted but generally vertical wall 111, and an inner vertical wall 113.
Referring to FIG. 17, a side sectional view taken along line 17--17 illustrates a bottom side 115 of the trough, as well as the edge of the slot 109 which is seen along the vertical wall 111 and bottom side 115 from the perspective of FIG. 17.
Referring to FIG. 18, a top view illustrates the bottom side 115 and the full extent of the slot 109 as going completely through the bottom side 115. In this configuration, the razor 41, even if it has a completely straight handle, can allow the handle to hang vertically downward. FIG. 19 illustrates the slot 109 from a front view. Again, the end walls 107 are optional and add strength to the trough portion 105.
Referring to FIG. 20, an eighth embodiment is a variation of the seventh embodiment combining trough support and clipped support. A support structure 121 has members which are identical to those of the support structure 101, but contains an important addition. A vertical member 123 extends downward from a point near the junction of the inner vertical wall 113 and the middle of the large clip portion 103. The vertical member 123 supports, in the case of FIGS. 20-23, an abbreviated length horizontal member 125. The horizontal member 125 supports a small clip 127.
Referring to FIG. 21, it can be seen that the razor 41 has a head which is angled with respect to its handle and thus the necessity for the horizontal member 125 to be extended slightly. Where the razor 41 has a straighter profile, the horizontal member 125 need not be present, or perhaps need not provide as much extension of the small clip 127 away from the large clip portion 103.
Referring to FIG. 28, an eighth embodiment of the present invention is illustrated as support structure 131 and has a clip 133 attached to a structure which includes a magnet 135 encased within a suction cup and magnet stabilization member 137. FIG. 27 illustrates a top view and a point of reference for the section lines about which FIG. 28 is taken. FIG. 29 illustrates a rear view which illustrates the surface of the magnet 135.
Referring to FIG. 24, a variation on the trough 105 structure of FIGS. 20-23 illustrates the magnet 135 and suction cup and magnet stabilization member 137 supporting the trough 105. The result is support structure 141. FIG. 26 gives a rear view of the suction cup and magnet stabilization member 137. FIG. 25 is a variation on the support structure 141 which has a vertical member 123 to support the small clip 127, similar to the embodiments illustrated in FIGS. 20-23.
Although the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art.
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Several embodiments of a disposable razor support structure include structures from which support is derived including (1) a clip for encircling and grasping the major portion of a can and which also grasps the disposable razor just below the head portion; (2) a cap support which engages a can in a manner identical to that of the way in which a cap engages the can; (3) a cap which engages a can; and (4) a magnetic attachment member which can adhere to either a can or other metal surface; (5) a horizontal can tray which can accommodate a can; and also structures for supporting a disposable razor including (1) a clip in the shape of an Ω which grasps the upper handle of a razor, and (2) a trough to gently support the head of the razor, either of which can draw support from any of the structures described above.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Japanese Patent Application No. 2012-072909 filed Mar. 28, 2012, the content of which is hereby incorporated herein by reference.
BACKGROUND
[0002] The present disclosure relates to a sewing machine that allows a clearance between a sewing needle and a hook point of a shuttle to be adjusted.
[0003] A known sewing machine mainly includes a bed, a pillar, an arm, and a head. The arm is provided with a drive shaft. The drive shaft may be driven by a sewing machine motor. The head is provided with a needle bar base. The needle bar base supports a needle bar. Due to the rotation of the drive shaft, the needle bar may be moved in the up-down direction. The bed is provided with a shuttle. The shuttle may be rotated in accordance with the rotation of a lower shaft, which may be rotated in conjunction with the drive shaft. An upper thread may be supplied to a sewing needle that is attached to the needle bar. A lower thread may be supplied from a bobbin that is housed in the shuttle. The upper thread and the lower thread may be interlaced by the needle bar and the shuttle working in cooperation with each other, thus forming a stitch on a work cloth.
[0004] A sewing machine is provided with a function to sew zigzag stitching. The zigzag stitching is sewing that is performed while the needle bar is swung left and right. An upper end portion of the needle bar base is swingably supported. The zigzag stitching is performed by moving a lower end portion of the needle bar base in the left-right direction.
[0005] In order to reliably form a stitch with a sewing machine, it is important to adjust a clearance between a sewing needle and a hook point of the shuttle. The clearance between the sewing needle and the hook point of the shuttle is hereinafter referred to as the needle gap. The needle gap may be adjusted for a left needle gap and a right needle gap. The left needle gap is a clearance between the sewing needle and the hook point when the sewing needle is in a left needle drop position (a left reference line position). The left reference line position is a leftmost needle drop position in the greatest zigzag width. The right needle gap is a clearance between the sewing needle and the hook point when the sewing needle is in a right needle drop position (a right reference line position). The right reference line position is a rightmost needle drop position in the greatest zigzag width. For example, in a known sewing machine, a plate is fixed to an arm by two screws. By displacing an attachment position of the plate in relation to the arm, it is possible to adjust the left and right needle drop positions. By adjusting the left and right needle drop positions, it is possible to adjust the needle gaps.
SUMMARY
[0006] In the above-described known sewing machine, a procedure when adjusting the needle gaps is as follows. First, the two screws fixing the plate to the arm may be loosened, such that the plate can be freely moved. The attachment position of the plate may be changed. The plate may be once more fixed to the arm by the screws. Thus, for example, in a case where the right needle gap is adjusted after the left needle gap has been adjusted, it is necessary to adjust the right needle gap while maintaining the adjusted left needle gap unchanged. As a result, an operation to adjust the needle gaps may be difficult.
[0007] Embodiments of the broad principles derived herein provide a sewing machine in which, after one of a left and a right needle gaps has been adjusted, the adjusted one of the needle gaps remains unchanged.
[0008] Embodiments provide a sewing machine that includes a needle bar, a needle bar base, a base frame, a guide member, and a fixing member. A sewing needle is attachable to a lower end portion of the needle bar. A needle bar base is configured to support the needle bar to allow the needle bar to be moved in an up-down direction. A first engagement portion is provided to a lower end portion of the needle bar base. A base frame is configured to swingably support an upper end portion of the needle bar base. A second engagement portion is provided to a lower end portion the base frame. A guide member includes a third engagement portion and a fourth engagement portion. The third engagement portion is configured to engage with the first engagement portion and guide movement of the first engagement portion in a predetermined direction. The fourth engagement portion is configured to engage with the second engagement portion. A fixing member is configured to fix the guide member to the base frame. When the needle bar base is in a reference position, a first reference line of the first engagement portion, a second reference line of the second engagement portion, and a third reference line of the fourth engagement portion are in a same straight line, and the guide member is configured to be swingable about the same straight line in a state in which fixing of the fixing member with respect to the base frame is loosened.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments will be described below in detail with reference to the accompanying drawings in which:
[0010] FIG. 1 is a perspective view of a sewing machine;
[0011] FIG. 2 is a perspective view showing an internal configuration of a left end portion of the sewing machine including a head;
[0012] FIG. 3 is a perspective view of a needle bar module;
[0013] FIG. 4 is an exploded perspective view of a needle bar support mechanism;
[0014] FIG. 5 is a perspective view of a base holder;
[0015] FIG. 6 is a perspective view of a needle bar base;
[0016] FIG. 7 is a perspective view of a lower side of a guide member, as seen from the front and right;
[0017] FIG. 8 is a perspective view of an upper side of the guide member, as seen from the front and right;
[0018] FIG. 9 is a diagram showing a state, as seen from above, of a relationship between the guide member and a left needle gap when the needle bar is positioned in a left reference line position; and
[0019] FIG. 10 is a diagram showing a state, as seen from above, of a relationship between the guide member and a right needle gap when the needle bar is positioned in a right reference line position.
DETAILED DESCRIPTION
[0020] Hereinafter, a sewing machine 1 according to an embodiment will be explained with reference to the drawings.
[0021] A configuration of the sewing machine 1 will be explained with reference to FIGS. 1 and 2 . In the following explanation, the lower right side, the upper left side, the lower left side, the upper right side, the upper side, and the lower side of FIG. 1 are respectively the front side, the rear side, the left side, the right side, the upper side, and the lower side of the sewing machine 1 . More specifically, a direction in which a pillar 3 , which is described below, extends is the up-down direction of the sewing machine 1 . A longitudinal direction of a bed 2 and an arm 4 is the left-right direction of the sewing machine 1 . An explanation of the structural members of the sewing machine 1 shown in FIGS. 3 to 10 is made with reference to the front-rear direction and the left-right direction when the structural members are attached to the sewing machine 1 .
[0022] As shown in FIG. 1 , the sewing machine 1 is provided with the bed 2 , the pillar 3 , the arm 4 , and a head 5 . The bed 2 extends in the left-right direction. A horizontal shuttle 8 (refer to FIG. 2 ) and the like are provided in the interior of the left portion of the bed 2 . The pillar 3 extends upward from the right end of the bed 2 . A sewing machine motor (not shown in the drawings) and the like are provided in the interior of the pillar 3 . The arm 4 extends to the left from the upper side of the pillar 3 such that the arm 4 faces the upper surface of the bed 2 . A drive shaft 51 (refer to FIG. 2 ) and the like are provided in the interior of the arm 4 . The head 5 is provided on the left side of the arm 4 . A needle bar module 10 (refer to FIG. 2 ) and the like are provided in the interior of the head 5 . The needle bar module 10 includes a needle bar support mechanism 100 , which will be described below. The needle bar support mechanism 100 includes a needle bar 110 that can be moved in the up-down direction. The needle bar 110 is exposed from the lower side of the head 5 , and extends downward. A sewing needle 101 may be attached to the lower end of the needle bar 110 .
[0023] As shown in FIG. 2 , a needle plate 11 is provided on the upper portion of the bed 2 . The needle plate 11 has a needle hole 12 that is positioned directly below the needle bar 110 . The sewing needle 101 that is attached to the needle bar 110 can be inserted through the needle hole 12 . The horizontal shuttle 8 is provided below the needle plate 11 . The horizontal shuttle 8 may house a bobbin (not shown in the drawings) on which a lower thread (not shown in the drawings) is wound. A lower shaft 21 may be rotated in conjunction with the drive shaft 51 . The horizontal shuttle 8 may be rotated in the horizontal direction in accordance with the rotation of the lower shaft 21 . The horizontal shuttle 8 includes a hook point 9 (refer to FIG. 9 ). The leading end portion of the hook point 9 faces a peripheral direction of the horizontal shuttle 8 . The hook point 9 may seize a loop of an upper thread. When the needle bar 110 is lowered by a needle bar drive mechanism 16 , the sewing needle 101 attached to the needle bar 110 may approach the hook point 9 of the horizontal shuttle 8 . A feed dog 13 is provided under the needle plate 11 . The feed dog 13 may move a work cloth by a predetermined feed distance.
[0024] A configuration of the needle bar module 10 , which is provided on the head 5 , will be explained with reference to FIGS. 2 to 8 . The needle bar module 10 shown in FIGS. 2 and 3 is a module that is formed by integrating the needle bar support mechanism 100 , the needle bar drive mechanism 16 , a thread take-up drive mechanism 17 , and a presser foot lifting mechanism 18 . The needle bar support mechanism 100 supports the needle bar 110 . The sewing needle 101 may be attached to the needle bar 110 . The needle bar drive mechanism 16 may drive the needle bar 110 to reciprocate in the up-down direction. The thread take-up drive mechanism 17 may drive a thread take-up lever 170 (refer to FIG. 3 ). The presser foot lifting mechanism 18 may raise and lower a presser bar 180 (refer to FIG. 3 ). The needle bar module 10 is fixed to a machine frame 6 inside the head 5 . The rotation of the drive shaft 51 may be transmitted to the needle bar drive mechanism 16 and the thread take-up drive mechanism 17 , so that the needle bar drive mechanism 16 and the thread take-up drive mechanism 17 may be driven.
[0025] As shown in FIG. 3 to FIG. 5 , a base holder 120 of the needle bar support mechanism 100 is foamed of a metal plate that extends in the up-down direction. A support shaft 173 , which extends in the left-right direction, is fixed to the base holder 120 , slightly above the center of the base holder 120 in the up-down direction. The length of the support shaft 173 is longer than the length, in the left-right direction, of the base holder 120 . The support shaft 173 protrudes from the base holder 120 in the left and right directions. The left end portion of the support shaft 173 is fixed to the machine frame 6 by a presser plate 175 and a screw 174 (refer to FIG. 2 ). Although not shown in the drawings, the right end portion of the support shaft 173 is also fixed to the machine frame 6 in the same manner. Although not shown in the drawings, the lower end portion of the base holder 120 is fixed to the machine frame 6 such that an inclination (as seen from the side) of the base holder 120 can be adjusted. In a case where the screw 174 that fixes the support shaft 173 is slightly loosened, the base holder 120 may be swung with the support shaft 173 as the center of rotation, in the side view. Thus, the base holder 120 may be fixed to the machine frame 6 after the inclination of the base holder 120 , namely the posture of the base holder 120 in relation to the machine frame 6 , has been adjusted.
[0026] A support portion 122 is provided on the lower end portion of the base holder 120 . The support portion 122 is a portion that extends toward the front from the lower edge of the base holder 120 . A support hole 185 is formed in a position close to the right side of the support portion 122 . The support hole 185 penetrates the support portion 122 in the up-down direction. A boss portion 123 is provided in a position close to the front left side of the support portion 122 . The boss portion 123 is a portion that protrudes downward from the support portion 122 in a cylindrical shape. A central line of the boss portion 123 is denoted by Q. A screw hole 129 is formed in a position close to the rear left side of the support portion 122 . The screw hole 129 penetrates the support portion 122 in the up-down direction.
[0027] As shown in FIG. 3 , the presser bar 180 that extends in the up-down direction is inserted through the support hole 185 (refer to FIG. 4 ). A presser foot 181 is provided on the lower end portion of the presser bar 180 . A support piece 182 is attached to the upper portion of the base holder 120 . The upper end portion of the presser bar 180 is supported by the support piece 182 . In this manner, the presser bar 180 is supported on the base holder 120 such that the presser bar 180 can be moved in the up-down direction. A presser spring (not shown in the drawings) is provided around the presser bar 180 . The presser bar 180 is biased downward by the biasing force of the presser spring. A lever shaft 184 is provided on the lower right portion of the base holder 120 . The lever shaft 184 protrudes toward the front. A presser lever 183 is supported such that the presser lever 183 may be pivoted in relation to the lever shaft 184 . When the presser lever 183 is operated, the presser bar 180 and the presser foot 181 are raised and lowered. The presser foot lifting mechanism 18 includes the presser bar 180 , the presser spring, and the presser lever 183 , which are described above.
[0028] The thread take-up lever 170 and the thread take-up drive mechanism 17 are disposed at the right of the base holder 120 . The thread take-up lever 170 and the thread take-up drive mechanism 17 are known mechanisms and are briefly explained here. A thread take-up crank 52 is fixed to the left end portion of the drive shaft 51 . The thread take-up crank 52 may be rotated integrally with the drive shaft 51 . The thread take-up crank 52 may be rotated in accordance with the rotation of the drive shaft 51 , so that the thread take-up drive mechanism 17 may be driven. By the driving of the thread take-up drive mechanism 17 , the thread take-up lever 170 may be moved in the up-down direction in synchronization with the reciprocating motion in the up-down direction of the needle bar 110 .
[0029] As shown in FIGS. 4 and 5 , a support shaft 124 is provided on an upper end portion 118 of the base holder 120 . The support shaft 124 extends toward the front. The support shaft 124 pivotably supports a needle bar base 130 that will be described below. The support shaft 124 is provided with a base end portion 125 , a trunk portion 126 , and a leading end portion 127 . The trunk portion 126 is formed having a smaller diameter than that of the base end portion 125 . The trunk portion 126 extends longer in the front-rear direction. The leading end portion 127 is formed having a diameter that is smaller than a diameter of the trunk portion 126 . A male screw 128 is formed on the leading end portion 127 . The male screw 128 is a right-hand thread screw. Further, an attachment portion 119 is formed on the base holder 120 . The attachment portion 119 is a portion that extends toward the front from the upper left portion of the base holder 120 . A plate spring 150 , which will be described below, is fixed to the attachment portion 119 .
[0030] As shown in FIGS. 4 and 6 , the needle bar base 130 is formed of a metal plate that extends in the up-down direction. A through hole 131 is formed in an upper end portion 137 of the needle bar base 130 . The through hole 131 penetrates the upper end portion 137 in the front-rear direction. The inner diameter of the through hole 131 is slightly larger than the outer diameter of the trunk portion 126 of the support shaft 124 . The through hole 131 is formed in a tapered shape by chamfering, such that the through hole 131 becomes narrower from the front toward the rear. Further, the needle bar base 130 includes a pressing portion 132 . The pressing portion 132 is a portion that extends downward from the upper rear end portion of the needle bar base 130 . A groove 139 is formed in the pressing portion 132 . The groove 139 is generally an inverted U-shape. The width of the groove 139 in the left-right direction is slightly larger than the outer diameter of the trunk portion 126 of the support shaft 124 . The trunk portion 126 fits into the groove 139 .
[0031] The needle bar base 130 includes a support portion 133 . The support portion 133 is a portion that extends toward the rear from the lower edge of the needle bar base 130 . A hole 134 (refer to FIG. 3 ) is formed in a position toward the right side of the support portion 133 . The hole 134 penetrates the support portion 133 in the up-down direction. A left portion of the support portion 133 protrudes further to the rear than a right portion of the support portion 133 . A cylindrical pin 135 is provided on the rear end portion of the left portion of the support portion 133 . The pin 135 protrudes upward from the support portion 133 . A central line of the pin 135 is denoted by P. A direction in which the pin 135 extends is parallel to the needle bar 110 . The outer diameter of the pin 135 is generally the same as the size of a groove width of a long groove 191 that is provided in the guide member 190 , which will be described below.
[0032] The needle bar base 130 includes a bent portion 136 . The bent portion 136 is a portion that extends to the rear from a portion of the needle bar base 130 above the center of the needle bar base 130 in the up-down direction such that the bent portion 136 is parallel to the support portion 133 . A hole (not shown in the drawings) having a same inner diameter as a diameter of the hole 134 is formed in the bent portion 136 . As shown in FIG. 3 , the needle bar 110 is inserted into and supported by the hole 134 and the hole of the bent portion 136 , such that the needle bar 110 may be moved in the up-down direction. An attachment portion 111 is provided on the lower end portion of the needle bar 110 . The sewing needle 101 may be attached to and removed from the attachment portion 111 .
[0033] As shown in FIG. 3 , a compression coil spring 155 is mounted around the outer periphery of the trunk portion 126 . The rear end of the compression coil spring 155 is in contact with a stepped portion between the trunk portion 126 and the base end portion 125 . The support shaft 124 is inserted through the through hole 131 of the needle bar base 130 and the groove 139 . In this manner, the needle bar base 130 is supported by the support shaft 124 in a state in which the needle bar base 130 can be rotated around the support shaft 124 . The leading end of the compression coil spring 155 is in contact with the pressing portion 132 of the needle bar base 130 .
[0034] A disc-shaped adjustment dial 140 is attached to the leading end portion 127 of the support shaft 124 . Although not shown in detail in the drawings, a hole is provided in the center of the adjustment dial 140 . The trunk portion 126 of the support shaft 124 may be inserted through the hole in the adjustment dial 140 . A nut fixing portion (not shown in the drawings) is formed to the front of the adjustment dial 140 . The nut fixing portion is a recessed portion that is formed in a position such that the center of the nut fixing portion is concentric with the center of the hole in the adjustment dial 140 . A nut 141 is fitted into and fixed to the nut fixing portion. A hemispheric contact portion is formed around the periphery of the hole in the adjustment dial 140 . A straight knurl is formed on an outer peripheral surface of the adjustment dial 140 .
[0035] As shown in FIGS. 3 and 4 , the support shaft 124 is inserted through the through hole 131 of the needle bar base 130 . The leading end portion 127 of the support shaft 124 is inserted through the hole in the adjustment dial 140 . The male screw 128 formed on the leading end portion 127 is screwed into a female screw of the nut 141 . The contact portion of the adjustment dial 140 is in contact with the tapered surface of the through hole 131 of the needle bar base 130 . At this time, the compression coil spring 155 is pressed in the rearward direction by the pressing portion 132 of the needle bar base 130 , and is compressed in the axial direction of the support shaft 124 . The compression coil spring 155 presses the pressing portion 132 of the needle bar base 130 toward the side of the leading end portion 127 , from the side of the base end portion 125 of the support shaft 124 . In other words, between the base holder 120 and the adjustment dial 140 , the needle bar base 130 is maintained in a state of being biased toward the adjustment dial 140 , due to the biasing force of the compression coil spring 155 . As described above, the male screw 128 is a right-hand thread screw. Thus, when the adjustment dial 140 is rotated in the clockwise direction, the adjustment dial 140 and the needle bar base 130 are moved toward the rear. In contrast, when the adjustment dial 140 is rotated in the anti-clockwise direction, the adjustment dial 140 and the needle bar base 130 are moved toward the front. In this manner, by rotating the adjustment dial 140 , the adjustment dial 140 may be moved in the axial direction of the support shaft 124 . In accordance with the movement of the adjustment dial 140 , the needle bar base 130 may be moved in the axial direction of the support shaft 124 .
[0036] As shown in FIG. 3 , the rectangular plate spring 150 is provided on the attachment portion 119 of the base holder 120 . The rear end (the base end) of the plate spring 150 is fixed to the attachment portion 119 by a screw. A leading end portion 152 of the plate spring 150 is in contact with the outer peripheral surface (the straight knurl) of the adjustment dial 140 , and biases the adjustment dial 140 in the rightward direction (in the radial direction). Specifically, the plate spring 150 regulates the rotation of the adjustment dial 140 .
[0037] As shown in FIG. 4 , the guide member 190 is provided on the lower surface of the support portion 122 of the base holder 120 . The guide member 190 is formed of a synthetic resin material. As shown in FIGS. 7 and 8 , the guide member 190 includes a flat plate portion 196 , which is generally L-shaped in a plan view, and a long groove portion 192 . A generally elliptical engaging hole 194 is formed in the flat plate portion 196 . A fixing screw 199 (refer to FIG. 4 ) is inserted through the engaging hole 194 . The fixing screw 199 is screwed into a screw hole 129 of the support portion 122 . By fastening the fixing screw 199 in the screw hole 129 , the guide member 190 is fixed to the base holder 120 .
[0038] The guide member 190 includes a protruding portion 195 . The protruding portion 195 is a portion of the flat plate portion 196 that protrudes toward the left. A user may grasp the protruding portion 195 with the user's fingers.
[0039] The long groove portion 192 of the guide member 190 protrudes downward from the flat plate portion 196 . The long groove 191 is formed in the center of the long groove portion 192 . The long groove 191 penetrates the long groove portion 192 in the up-down direction (the thickness direction). The long groove 191 has an arc shape that extends in the left-right direction. As will be explained in more detail below, a pin 135 is inserted into and engages with the long groove 191 . The pin 135 (refer to FIG. 4 ) is provided in the support portion 133 of the needle bar base 130 . The (inner side) dimension of the front-rear direction of the long groove 191 (the direction orthogonal to the extending direction of the long groove 191 ) is generally the same as the outer diameter of the pin 135 . A central line, in the front-rear direction, of the long groove 191 intersects with a central line R of a receiving hole 193 , which will be described below.
[0040] The receiving hole 193 is formed in the guide member 190 . The receiving hole 193 is positioned, in the upper surface of the guide member 190 , in the vicinity of the left end portion of the long groove 191 . The receiving hole 193 is formed in a circular shape. The central line of the receiving hole 193 is denoted by R. The inner diameter of the receiving hole 193 is generally the same as the outer diameter of the boss portion 123 provided on the support portion 122 of the base holder 120 . The depth (length) of the receiving hole 193 is slightly larger than the height of the boss portion 123 .
[0041] As shown in FIG. 4 , when the guide member 190 is fixed to the base holder 120 , the receiving hole 193 fits with the boss portion 123 . At that time, the central line R (refer to FIG. 7 ) of the receiving hole 193 is aligned with the central line Q (refer to FIG. 5 ) of the boss portion 123 .
[0042] When the fixing screw 199 is slightly loosened, the fitted state between the receiving hole 193 and the boss portion 123 may be maintained. There may be a slight gap (allowance) between the fixing screw 199 and the engaging hole 194 . Thus, the guide member 190 may be moved by an amount of the gap. Specifically, in a state in which the fixing screw 199 is slightly loosened, the guide member 190 may be rotated (pivoted) relative to the base holder 120 with the central lines R and Q as the center of rotation. The protruding portion 195 of the guide member 190 may protrude (refer to FIG. 3 ) further to the lateral side (to the left side) than the support portion 122 of the base holder 120 . When adjusting the needle gap, which is the clearance between the sewing needle 101 and the hook point 9 of the horizontal shuttle 8 (refer to FIGS. 9 and 10 ), the user may slightly loosen the fixing screw 199 . Then, by grasping and operating the protruding portion 195 with the user's fingers, the user can easily rotate the guide member 190 .
[0043] The pin 135 , which is provided on the support portion 133 of the needle bar base 130 , engages with the long groove 191 of the guide member 190 that is fixed to the base holder 120 . The pin 135 may be moved in the left-right direction along the long groove 191 while the pin 135 may not be moved in the front-rear direction. Thus, the needle bar base 130 may be guided in a direction in which the needle bar base 130 may be swung along the long groove 191 with which the pin 135 engages. Further, a range over which the needle bar base 130 may be swung is regulated by the long groove 191 . A needle bar swinging mechanism is a known mechanism and is therefore not illustrated in the drawings and a detailed explanation is omitted here. As shown in FIG. 2 , a connecting rod 53 , which extends in the left-right direction, is coupled to the front surface of the needle bar base 130 . The needle bar swinging mechanism is provided inside the pillar 3 . The needle bar swinging mechanism may move the connecting rod 53 in the left-right direction, so that the needle bar base 130 may be swung in the left-right direction.
[0044] As shown in FIG. 3 , a needle bar holder 163 of the needle bar drive mechanism 16 is provided on a middle portion of the needle bar 110 , in a position between the support portion 133 and the bent portion 136 . The needle bar holder 163 holds the needle bar 110 . The needle bar holder 163 is coupled to the leading end of a crank rod 161 . The crank rod 161 is connected to a needle bar crank 160 . The needle bar crank 160 is coupled, via a connecting pin 162 , to the thread take-up crank 52 (refer to FIG. 2 ). When the drive shaft 51 (refer to FIG. 2 ) is rotated, the thread take-up crank 52 is rotated. The needle bar crank 160 may be rotated in accordance with the rotation of the thread take-up crank 52 , and thus the crank rod 161 may be driven. The needle bar crank 160 , the crank rod 161 , and the needle bar holder 163 may work in cooperation with each other, and may convert the rotational movement of the drive shaft 51 into a reciprocating motion in the up-down direction. The needle bar 110 may be moved up and down in this manner.
[0045] In the sewing machine 1 of the present embodiment, a stitch may be formed on the work cloth by the needle bar 110 and the horizontal shuttle 8 working in cooperation with each other. At that time, the sewing needle 101 is attached to the needle bar 110 . An upper thread loop that is formed in the eye of the sewing needle 101 must be reliably picked up by the hook point 9 of the horizontal shuttle 8 . In a case where the upper thread loop cannot be picked up by the hook point 9 , a skipped stitch may occur in which the stitch is not formed. In this case, the sewing quality may deteriorate. In order to eliminate the skipped stitch, it is necessary to properly adjust the needle gap, which is the clearance between the sewing needle 101 and the hook point 9 . In the sewing machine 1 of the present embodiment, the user may adjust the needle gap by adjusting (rotating) the adjustment dial 140 . The needle bar 110 may be swung in the left-right direction. Thus, it is necessary to adjust the needle gap both when the sewing needle 101 is in the left needle drop position (the left reference line position) and when the sewing needle 101 is in the right needle drop position (the right reference line position).
[0046] In the present embodiment, it is assumed that the right needle gap is adjusted in the right reference line position after adjusting the left needle gap in the left reference line position. Hereinafter, an operation when adjusting a left needle gap X and a right needle gap Y will be explained with reference to FIGS. 9 and 10 . FIG. 9 and FIG. 10 are diagrams schematically showing relationships between a position of the guide member 190 , a position of the sewing needle 101 (the needle bar 110 ), and a position of the hook point 9 of the horizontal shuttle 8 , when seen from above the sewing machine 1 . In FIGS. 9 and 10 , a position of the guide member 190 is shown by dotted lines when the guide member 190 is rotated within a rotatable range. The guide member 190 may be rotated within the range of the allowance between the fixing screw 199 and the engaging hole 194 .
[0047] As shown in FIG. 9 , the needle bar base 130 may be swung such that a central axial line position of the sewing needle 101 (the needle bar 110 ) may be positioned on a left reference line position A. At that time, the pin 135 is positioned close to the left end of the long groove 191 of the guide member 190 . The central line P of the pin 135 may be aligned with the central line Q of the boss portion 123 and with the central line R of the receiving hole 193 that engages with the boss portion 123 . The guide member 190 may be rotated in relation to the base holder 120 with the central lines R and Q as the center of rotation. Thus, even when the guide member 190 is rotated within the rotatable range, the position of the central line P of the pin 135 does not change. Thus, the position of the needle bar base 130 that is provided with the pin 135 and the position of the sewing needle 101 that is attached to the needle bar 110 do not change, irrespective of the rotation of the guide member 190 . Specifically, in the left reference line position A, even if the guide member 190 is rotated, the position of the sewing needle 101 does not change. As a result, the left needle gap X does not change.
[0048] The adjustment of the left needle gap X may be performed by rotating the adjustment dial 140 provided on the needle bar support mechanism 100 . When the adjustment dial 140 is rotated, the needle bar base 130 is moved in the front-rear direction. As described above, the pin 135 of the needle bar base 130 is engaged with the long groove 191 of the guide member 190 such that the pin 135 may be moved in the left-right direction while the pin 135 may not be moved in the front-rear direction. In this way, even when the needle bar base 130 is moved in the front-rear direction, the position of the pin 135 in the front-rear direction does not change. As a result, the inclination of the needle bar base 130 may change slightly, generally centering on the position at which the pin 135 and the long groove 191 are engaged with each other. More specifically, the adjustment dial 140 may be moved to the front, in a side view of the needle bar support mechanism 100 . In this case, the upper portion of the needle bar base 130 may incline slightly to the front, generally centering on the position at which the pin 135 and the long groove 191 are engaged with each other. In contrast, the adjustment dial 140 may be moved to the rear. In this case, the upper portion of the needle bar base 130 may incline slightly to the rear, generally centering on the position at which the pin 135 and the long groove 191 are engaged with each other. By changing the inclination of the needle bar base 130 in this manner, the sewing needle 101 attached to the lower end portion of the needle bar 110 (which is supported by the needle bar base 130 ) may be moved. When the adjustment dial 140 is moved toward the front, the sewing needle 101 attached to the needle bar 110 is moved in a direction (to the rear) in which the sewing needle 101 comes closer to the hook point 9 . In contrast, when the adjustment dial 140 is moved toward the rear, the sewing needle 101 is moved in a direction (to the front) in which the sewing needle 101 is separated from the hook point 9 .
[0049] In actuality, the user may perform the adjustment in a state in which the needle plate 11 is removed. The user may look at the horizontal shuttle 8 from the side of the sewing machine 1 , and thus visually checks the clearance between the sewing needle 101 and the hook point 9 in the left reference line position A. The user may grasp the adjustment dial 140 with the user's fingers and may rotate the adjustment dial 140 . The adjustment dial 140 can easily be operated from the front face of the sewing machine 1 . As described above, when the adjustment dial 140 is rotated in the clockwise direction, the adjustment dial 140 and the needle bar base 130 are moved to the rear. Thus, the sewing needle 101 may be moved to the front and may separate from the hook point 9 . When the adjustment dial 140 is rotated in the anti-clockwise direction, the adjustment dial 140 and the needle bar base 130 are moved to the front. Thus, the sewing needle 101 may be moved to the rear and may approach the hook point 9 . The left needle gap X between the sewing needle 101 and the hook point 9 may be adjusted by the user rotating the adjustment dial 140 with the user's fingers in this manner.
[0050] When the adjustment of the left needle gap X is finished, next, the right needle gap Y may be adjusted. As shown in FIG. 10 , the needle bar base 130 may be swung such that the central axial line position of the sewing needle 101 (the needle bar 110 ) is positioned on the right reference line position B. At this time, the pin 135 may be positioned close to the right end of the long groove 191 of the guide member 190 . The central line P of the pin 135 may be displaced from the central line Q of the boss portion 123 and the central line R of the receiving hole 193 .
[0051] The user may slightly loosen the fixing screw 199 and may grasp the protruding portion 195 of the guide member 190 with the user's fingers to rotate (swing) the guide member 190 . The guide member 190 may be rotated with the central lines Q and R as the center of rotation. By rotating the guide member 190 , the position of the long groove 191 may be changed. The position of the pin 135 may change generally in the front-rear direction in accordance with the change in the position of the long groove 191 . The lower end of the needle bar base 130 may be moved to the front and the rear in accordance with the change in the position of the pin 135 . By the lower end of the needle bar base 130 moving to the front and the rear, the sewing needle 101 attached to the needle bar 110 may approach or separate from the hook point 9 . The user may look at the horizontal shuttle 8 from the side of the sewing machine 1 . While visually checking the clearance between the sewing needle 101 and the hook point 9 in the right reference line position B, the user may rotate the guide member 190 and may adjust the right needle gap Y.
[0052] By rotating the guide member 190 in this manner, it is possible to perform the adjustment of the right needle gap Y. As described above, even though the guide member 190 is rotated, the left needle gap X does not change. Thus, even while adjusting the right needle gap Y, it is possible to maintain the clearance for the left needle gap X. Then, when the adjustment of the right needle gap Y is finished, the user may tighten the fixing screw 199 and may fix the guide member 190 to the base holder 120 . In this manner, the adjustment of the left needle gap X and the right needle gap Y may be completed.
[0053] As explained above, in the sewing machine 1 of the present embodiment, the pin 135 of the needle bar base 130 and the long groove 191 of the guide member 190 engage with each other. The guide member 190 may be rotated with respect to the base holder 120 with the central lines Q and R of the boss portion 123 and the receiving hole 193 as the center of rotation. When the needle bar 110 is positioned in the left reference line position A, the central line P of the pin 135 , the central line Q of the boss portion 123 and the central line R of the receiving hole 193 are aligned and are on the same straight line. Thus, even when the guide member 190 is rotated, the position of the central line P does not change. In other words, even when the guide member 190 is rotated, the left needle gap X does not change. On the other hand, in a case where the needle bar 110 is positioned in the right reference line position B, when the guide member 190 is rotated, the central line P of the pin 135 is moved to the front and to the rear. In other words, when the guide member 190 is rotated, the right needle gap Y changes. Thus, after the left needle gap X has been adjusted in the left reference line position A, even when the right needle gap Y is adjusted in the right reference line position B, the left needle gap X does not change. As a result, it is possible to easily perform the adjustment of the left and the right needle gaps.
[0054] Due to the simple configuration in which the pin 135 of the needle bar base 130 is inserted into the long groove 191 of the guide member 190 , the guide member 190 and the needle bar base 130 engage with each other. Thus, it is possible to lower the cost of the sewing machine 1 .
[0055] Due to the simple configuration in which the receiving hole 193 of the guide member 190 is fitted with the boss portion 123 of the base holder 120 , the base holder 120 and the guide member 190 engage with each other. Thus, it is possible to lower costs.
[0056] The protruding portion 195 protrudes from the base holder 120 . The user may therefore grasp the protruding portion 195 with the user's fingers and may easily rotate the guide member 190 . Thus, it is possible to easily adjust the position of the needle bar 110 .
[0057] The present disclosure is not limited to the above-described embodiment and various modifications may be made. The guide member 190 is formed of the synthetic resin material. However, the guide member 190 may be formed of a metal material. The long groove 191 penetrates in the thickness direction of the guide member 190 . However, as far as the length of the long groove 191 is sufficient to engage the pin 135 , the long groove 191 need not necessarily penetrate the guide member 190 .
[0058] In the present embodiment, after the left needle gap X has been adjusted in the left reference line position A, the right needle gap Y may be adjusted in the right reference line position B. However, the sewing machine may be configured such that the left needle gap X can be adjusted in the left reference line position A after the right needle gap Y has been adjusted in the right reference line position B. In this case also, it is possible to easily perform the adjustment of the left and the right needle gaps.
[0059] 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 needle bar, a needle bar base, a base frame, a guide member, and a fixing member. A sewing needle is attachable to a lower end portion of the needle bar. The needle bar base is configured to support the needle bar to allow the needle bar to be moved in an up-down direction. A first engagement portion is provided to a lower end portion of the needle bar base. The base frame is configured to swingably support an upper end portion of the needle bar base. A second engagement portion is provided to a lower end portion the base frame. A guide member includes a third engagement portion configured to engage with the first engagement portion and guide movement of the first engagement portion in a predetermined direction and a fourth engagement portion configured to engage with the second engagement portion.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part of U.S. Ser. No. 09/025295 filed Feb. 13, 1998, having benefit of 60/046,626 filed May 16, 1997.
BACKGROUND OF THE INVENTION
[0002] The present invention concerns conformationally semi-constrained analogs of substituted quinoxaline 2,3-diones having utility as glutamate receptor antagonists. The quinoxaline 2,3-dione system is substituted by an amino acid derivative or nitrogen heterocyclic ring which includes bioisosteres of carboxylic acid derivatives via a carbon atom linkage. The compounds are active as excitatory amino acid receptor antagonists acting at glutamate receptors, including either or both N-methyl-D-aspartate (NMDA) receptors and non-NMDA receptors such as the I-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor and the kainate receptor. The invention also relates, therefore, to the use of those quinoxaline-2,3-diones as neuroprotective agents for treating conditions such as cerebral ischemia or cerebral infarction resulting from a range of phenomena, such as thromboembolic or hemorrhagic stroke, cerebral vasospasms, hypoglycemia, cardiac arrest, status epilepticus, perinatal asphyxia, anoxia such as from drowning, pulmonary surgery, and cerebral trauma, as well as to treat chronic neurodegenerative disorders such as Alzheimer's Disease, Parkinsonism, and Huntington's Disease, and seizure disorders and pain. The compounds of the present invention may also be useful in the treatment of schizophrenia, epilepsy, anxiety, pain, and drug addiction.
[0003] Excessive excitation by neurotransmitters can cause the degeneration and death of neurons. It is believed that this degeneration is in part mediated by the excitotoxic actions of the excitatory amino acids (EAA) glutamate and aspartate at the N-methyl-D-aspartate (NMDA) receptor, the I-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor, and the kainate receptor. AMPA/kainate receptors may be referred to jointly as non-NMDA receptors. This excitotoxic action is considered responsible for the loss of neurons in cerebrovascular disorders such as cerebral ischemia or cerebral infarction resulting from a range of conditions, such as thromboembolic or hemorrhagic stroke, cerebral vasospasm, hypoglycemia, cardiac arrest, status epilepticus, perinatal asphyxia, anoxia such as from drowning, pulmonary surgery, and cerebral trauma, as well as lathyrism, Alzheimer's Disease, Parkinson's Disease, and Huntington's Disease.
[0004] Several classes of quinoxalinedione derivatives have been disclosed as glutamate (EAA) receptor antagonists. For example, among excitatory amino acid receptor antagonists recognized for usefulness in the treatment of disorders are those that block AMPA receptors (Bigge C.F. and Malone T. C., Curr. Opin. Ther. Pat., 1993:951; Rogawski M. A., TiPS, 1993; 14:325). AMPA receptor antagonists have prevented neuronal injury in several models of global cerebral ischemia (Li H. and Buchan A. M., J. Cerebr. Blood Flow Metab., 1993;13:933; Nellgard B. and Wieloch T., J. Cerebr. Blood Flow Metab., 1992;12:2) and focal cerebral ischemia (Bullock R., Graham D. I., Swanson S., and McCulloch J., J. Cerebr. Blood Flow Metab., 1994;14:466; Xue D., Huang Z.-G., Barnes K., Lesiuk H. J., Smith K. E., and Buchan A. M., J. Cerebr. Blood Flow Metab., 1994;14:251). AMPA antagonists have also shown efficacy in models for analgesia (Xu X. -J., Hao J. -X, Seiger A., and Wiesenfeld-Hallin Z., J. Pharmacol. Exp. Ther., 1993;267: 140), and epilepsy (Namba T., Morimoto K., Sato K., Yamada N., and Kuroda S., Brain Res., 1994;638:36; Brown S. E. and McCulloch J., Brain Res., 1994;641:10; Yamaguchi S. I., Donevan S. D., and Rogawski M. A., Epilepsy Res., 1993;15:179; Smith S. E., Durmuller N., and Meldrum B. S., Eur. J. Pharmacol., 1991;201:179). AMPA receptor antagonists have also demonstrated promise in chronic neurodegenerative disorders such as Parkinsonism (Klockgether T., Turski L., Honore T., Zhang Z., Gash D. M., Kurlan R., and Greenamyre J. T., Ann. Neurol., 1993;34(4):585-593).
[0005] Excitatory amino acid receptor antagonists that block NMDA receptors are also recognized for usefulness in the treatment of disorders. NMDA receptors are intimately involved in the phenomenon of excitotoxicity, which may be a critical determinant of outcome of several neurological disorders. Disorders known to be responsive to blockade of the NMDA receptor include acute cerebral ischemia (stroke or cerebral trauma, for example), muscular spasm, convulsive disorders, neuropathic pain, and anxiety, and may be a significant causal factor in chronic neurodegenerative disorders such as Parkinson's Disease (Klockgether T. and Turski L., Ann. Neurol., 1993;34:585-593), human immunodeficiency virus (HIV) related neuronal injury, amyotrophic lateral sclerosis (ALS), Alzheimer's Disease (Francis P. T., Sims N. R., Procter A. W., and Bowen D. M., J. Neurochem., 1993;60(5):1589-1604), and Huntington's Disease. (See Lipton S., TINS, 1993;16(12):527-532; Lipton S. A. and Rosenberg P. A., New Eng. J. Med., 1994;330(9):613-622; and Bigge C.F., Biochem. Pharmacol., 1993;45:1547-1561 and references cited therein.) NMDA receptor antagonists may also be used to prevent tolerance to opiate analgesia or to help control withdrawal symptoms from addictive drugs (European Patent Application 488,959A).
[0006] The compounds of the instant invention differ from the art in that they provide non-coplanar compounds with greater solubility and, therefore, better ability to penetrate the blood-brain barrier. These are important attributes in pharmaceuticals. It is a further object to cover conformationally semi-constrained quinoxaline-2,3-dione derivatives.
SUMMARY OF THE INVENTION
[0007] Described are quinoxaline-dione compounds of Formula I
[0008] wherein
[0009] R is an amino acid, a derivative thereof, or nitrogen heterocyclic ring which is saturated or unsaturated of from 5 to 8 members which may have additional oxygen or sulfur atoms therein and which may be substituted by one or more substituents selected from:
[0010] alkyl of from 1 to 4 carbon atoms,
[0011] hydroxyl,
[0012] alkoxy of from 1 to 4 carbon atoms,
[0013] —CF 3 ,
[0014] —CN,
[0015] -amino,
[0016] —C(O)R 11 , or
[0017] —(CH 2 ) n -aryl of from 6 to 12 carbon atoms;
[0018] R must be attached through a carbon to the quinoxalinyl ring;
[0019] R 1 is H, alkyl of from 1 to 4 carbon atoms, phosphonoalkyl of from 1 to 4 carbon atoms, phosphoroalkyl of from 1 to 4 carbon atoms, carboxyalkyl of from 1 to 4 carbon atoms, —(CH 2 ) m C(O)R 11 , or hydroxy;
[0020] R 2 is hydrogen, hydroxy, or amine;
[0021] R 3 and R 4 are each independently H, alkyl of from 1 to 4 carbon atoms, cycloalkyl of from 5 to 7 carbon atoms, alkenyl of from 2 to 6 carbon atoms, halogen, haloalkyl of from 1-6 carbon atoms, nitro, cyano, SO 2 CF 3 , CH 2 SO 2 R 7 , (CH 2 ) m CO 2 R 7 , (CH 2 ) m CONR 7 R 8 , (CH 2 ) m SO 2 NR 8 R 9 , or NHCOR 7 ;
[0022] R 5 is H, alkyl of from 1 to 4 carbon atoms, alkenyl of from 2 to 6 carbon atoms, cycloalkyl of from 5 to 7 carbon atoms, halogen, haloalkyl of from 1 to 4 carbon atoms, —(CH 2 ) m aryl of from 6 to 10 carbon atoms, nitro, cyano, SO 2 CF 3 , (CH 2 ) m CO 2 R 9 , (CH 2 ) m CONR 9 R 11 , SO 2 NR 9 R 10 , SO 2 R 7 , (CH 2 ) m SO 2 R 7 , NHCOR 9 , —(CH 2 ) m heterocyclic of from 6 to 10 atoms which may contain nitrogen, oxygen, sulfur, and/or —(CH 2 ) n R;
[0023] R 5 may be joined at R 4 to form a cyclic aromatic or a heterocyclic ring of from 5 to 7 members which may contain nitrogen, oxygen, or sulfur;
[0024] R 7 , R 8 , R 9 , and R 10 are each independently selected from hydrogen, alkyl of from 1 to 4 carbon atoms, cycloalkyl of from 5 to 7 carbon atoms, haloalkyl of from 1 to 4 carbon atoms, or —(CH 2 ) m R 11 ;
[0025] R 11 is alkyl or alkoxy of from 1 to 4 carbon atoms, hydroxy, or amino;
[0026] m is an integer of from 0 to 4;
[0027] n is an integer of from 0 to 4;
[0028] or a pharmaceutically acceptable salt thereof.
[0029] Preferred compounds are those of Formula I wherein
[0030] R is an amino acid attached via an alkyl side-chain to the quinoxaline-2,3-dione ring at C-5 or C-6. The amino acid is R or S or RS(±). The point of attachment is I- to the carboxylic acid moiety, e.g.,
[0031] wherein
[0032] p is an integer of from 0 to 4;
[0033] R 12 is —OH, alkoxy, or —NR 7 R 8 ;
[0034] R 13 is H, OH, C(O)CH 3 , protecting groups such as alkyl, aralkyl, or aryl, Boc, CBZ, FMOC;
[0035] wherein
[0036] m′ is an integer of from 1 to 3;
[0037] X, Y, Z, and W are each independently S, O, N, or C.
[0038] Or R is a nitrogen heterocyclic ring of 5 to 7 members with additional oxygen or sulfur atoms therein, and which includes bioisosteres of carboxylic acid, ester or amide, attached to the 5- or 6-quinoxalinyl side-chain via a carbon in the ring.
[0039] Some of the preferred compounds of the invention are selected from:
[0040] [(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-amino] acetic acid tert-butyl ester;
[0041] [(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-methylamino]-acetic acid, tert-butyl ester;
[0042] 3-[(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-amino]-propionic acid, tert-butyl ester;
[0043] (S)-2-[(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-amino]-3-phenylpropionic acid, tert-butyl ester;
[0044] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid dimethylamide;
[0045] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid methylamide;
[0046] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid benzylamide;
[0047] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid, 4-methoxy-benzylamide;
[0048] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid phenylamide;
[0049] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid (4-methoxyphenyl) amide;
[0050] (2,3-Dimethoxy-6-methyl-7-nitro-quinoxalin-5-yl)-piperazin-1-yl methanone;
[0051] [1,4]Diazepan-1-yl-(2,3-dimethoxy-6-methyl-7-nitro-quinoxalin-5-yl) methanone; and
[0052] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid, p-tolylamide.
[0053] For a description of bioisosteres see Annual Reports in Med. Chem., 1986;21:283 ; Chem. Soc. Reviews, 1979:563 ; Chemical Reviews, 1996;96:3147.
[0054] Common bioisosteres are:
[0055] Common preferred heterocycles are:
[0056] wherein R′ and R″ are independently H, alkyl, cycloalkyl, heterocycloalkyl, aralkyl, heteroaralkyl, aryl, heteroaryl, haloalkyl, CO 2 R 7 , CONR 7 R 8 , (CH 2 ) m SO 2 NR 8 R 9 , C(O)R 7 , SO 2 CF 3 , and CH 2 SO 2 R 7 .
[0057] Also described is a method for or treatment of neurodegenerative disorders including ALS, cerebral ischemia caused by cerebral trauma, stroke, hypoglycemia, heart attack, and surgery; anxiety and schizophrenia; and chronic neurodegenerative disorders such as Huntington's Disease, ALS, Parkinsonism, and Alzheimer's Disease. The compounds of this invention may also be employed as analgesics or in the treatment of epilepsy.
DETAILED DESCRIPTION
[0058] The present invention is concerned with compounds of Formula I. The compounds are prepared according to one or more of the following schemes.
TABLE ANALOGS OF 14 No. R Yield 14a 77% 14b 74% 14c 68% 14d 57% 14e Me 2 N 100% 14f MeNH 76% 14g 84% 14h 47% 14i 62% 14j 66% 14k 86% 14l 87% 14m 65%
[0059] [0059]
GENERAL EXPERIMENTAL
Scheme I
[0060] Step (a) involves formation of isatoic anhydride as shown in formula 2 by reacting the anthranilic acid derivative as shown in formula 1 with phosgene in the presence of an inorganic base such as aqueous sodium carbonate. The reaction is carried out at temperatures ranging from 0° C. to room temperature.
[0061] Step (b) involves bromination of the isatoic anhydride as shown in formula 2 to the bromo derivative as shown in formula 3 by reacting the anhydride with bromine in solution of AcOH/TFA at temperatures ranging from 0° C. to room temperature. Aqueous workup yields the desired bromo derivative.
[0062] Step (c) involves nitration of the isatoic anhydride shown in formula 3 with nitrating mixtures, preferably KNO 3 /H 2 SO 4 , to give the nitro derivative as shown in formula 4. The reaction is carried out at temperatures ranging from 0° C. to room temperature, preferably doing the addition of the nitrating mixtures at 0° C.
[0063] Step (d) involves opening of the isatoic anhydride derivative as shown in formula 4 with an alcohol, preferably methanol. The reaction is carried out at reflux temperatures to give the desired methyl ester as shown in formula 5.
[0064] Step (e) involves catalytic reduction of the nitroaniline derivative as shown in formula 5 to the corresponding o-phenylenediamine derivative as shown in formula 6 using Raney Nickel as the catalyst with protic solvents, preferably methanol, under hydrogen atmosphere of up to 50 psi (in the presence of a base, preferably triethylamine).
[0065] Step (f) involves cyclization of the o-phenylenediamine derivative as shown in formula 6 to the corresponding quinoxaline-2,3-dione derivative as shown in formula 7. The diarnine derivative is reacted with oxalic acid derivatives, preferably dimethyl oxalate, in a polar solvent such as methanol or ethereal solvent such as THF or aqueous acids such as hydrochloric acid. The reaction is carried out at reflux temperatures.
[0066] Step (g) involves nitration of the quinoxaline-2,3-dione derivative as shown in formula 7 to the corresponding 7-nitro derivative as shown in formula 8. The nitration is carried out with a nitrating mixture of KNO 3 /H 2 SO 4 , and product is isolated by normal aqueous workup.
[0067] Step (h) involves hydrolysis of the ester derivative as shown in formula 8 to the corresponding acid derivative as shown in formula 9. The hydrolysis is carried out in the presence of a base, preferably KOH, in a water soluble solvent such as dioxane or methanol.
Scheme II
[0068] Step (a) involves the formation of protected hydrazide derivative as shown in formula 3 of the acid derivative as shown in formula 1 by coupling a monoprotected hydrazine derivative, preferably Boc-hydrazine, in the presence of coupling agents such as CDI or EDAC or via a reactive intermediate such as mixed anhydride, preferably via EDAC, in the presence of activating agents such as HOBt and DMAP in polar solvents such as dimethylformamide. The product is isolated by a normal aqueous workup.
[0069] Step (b) involves the deprotection of the hydrazine derivative shown in formula 3 to the corresponding hydrazide derivative shown in formula 4. The deprotection is carried out under acidic conditions such as aqueous HCl, or HCl saturated in organic solvent such as chloroform or dioxane. Alternatively, hydrazide derivative 4 is synthesized as shown in Step (c). Thus, compound shown in formula 4 is synthesized by reacting carboxylic acid ester derivative as shown in formula 2 with hydrazine with or without a solvent such as dioxane, THF or DMF, preferably neat, at temperatures ranging from room temperature to reflux, preferably reflux. The product is isolated by aqueous workup.
[0070] Step (d) involves cyclization of the hydrazide derivative as shown in formula 4 to the corresponding oxadiazole derivative as shown in formula 6 by reacting the hydrazide derivative with cyanogen bromide in the presence of inorganic bases such as sodium carbonate, sodium bicarbonate or potassium bicarbonate, preferably potassium bicarbonate, in polar solvents such as water, DMF or DMSO, preferably water, at temperatures ranging from room temperature to reflux, preferably elevated temperatures of 70° C. to 80° C.
[0071] Step (e) involves cyclization of the hydrazide derivative as shown in formula 4 to the corresponding oxadiazole derivative as shown in formula 5 by reacting the hydrazide derivative with bif 1 nctional acylating agent such as phosgene or diethyl carbonate, preferably phosgene, in a hydrocarbon solvent such as benzene or toluene, or ethereal solvent such as THF, preferably THF, at temperatures ranging from room temperature to reflux, preferably room temperature.
[0072] Step (f) involves cyclization of the hydrazide derivative as shown in formula 4 to the corresponding oxadiazole derivative as shown in formula 7 by reacting the hydrazide derivative as shown in formula 4 with a disulfide agent such as carbon disulfide in the presence of inorganic bases such as sodium carbonate, sodium hydroxide or potassium carbonate or potassium hydroxide. Reaction is worked up under acidic conditions to give the desired product.
[0073] Steps (g) and (h) involve the cyclization of semicarbazide derivative formed in situ by reacting the ester derivative as shown in formula 2 with semicarbazide salt in the presence of an alkoxide base such as sodium methoxide or potassium t-butoxide, preferably sodium methoxide, in polar solvent such as methanol or butanol, preferably methanol, at temperatures ranging from room temperature to reflux. Acidic workup (Step h), preferably with methanolic HCl, would give the desired triazole derivative as shown in formula 6.
Scheme III
[0074] Step (a) involves the cyclization of hydrazide derivative as shown in formula 1 to the corresponding triazole derivative as shown in formula 2 with an isocyanate derivative such as methyl isocyanate in the presence of a polar solvent such as ethanol in the presence of a base such as sodium or potassium hydroxide. Acidic workup, preferably with aqueous HCl, gave the desired product.
[0075] Step (b) involves the conversion of oxadiazole derivative as shown in formula 3 to the corresponding triazole derivative as shown in formula 4 by reacting the oxadiazole derivative as shown in formula 3 with hydrazine in the presence of polar solvent such as ethanol at temperatures ranging from room temperature to reflux, preferably reflux, to give the product after acid workup, preferably with HCl.
Scheme IV
[0076] Step (a) involves the formation of the thiosemicarbazide derivative as shown in formula 2 by reacting the acid derivative as shown in formula 1 in the presence of coupling agents such as CDI or EDAC, or via activated acid derivatives such as anhydride or acid chloride; preferably EDAC in the presence of activating agent such as HOBt in polar solvents such as DMF at temperatures ranging from room temperature to 60° C., preferably room temperature.
[0077] Step (b) involves the cyclization of thiosemicarbazide derivative as shown in formula 2 to the corresponding triazole derivative as shown in formula 3 in the presence of inorganic bases such as potassium hydroxide or alkoxide bases such as sodium methoxide in polar solvents such as methanol. Alternatively, Step (c) shows that the semicarbazide derivative can be cyclized to form the corresponding thiadiazole derivative as shown in formula 4 under acidic conditions. The cyclization is carried out in the presence of acids such as methanesulfonic acid in polar solvents such as DMF at elevated temperatures, preferably around 100° C.
Scheme V
[0078] Step (a) involves the coupling of the acid derivative as shown in formula 1 with the hydrazine derivative as shown in formula 2 in the presence of coupling agents such as CDI or EDAC, preferably EDAC, in the presence of activating agents such as HOBt in polar solvents such as DMF at temperatures ranging from room temperature to 40° C., preferably room temperature.
[0079] Step (b) involves cyclization of the hydrazide derivative as shown in formula 3 to the corresponding thiadiazole derivative as shown in formula 4 under acidic conditions, preferably p-toluenesulfonic acid, or under oxidative conditions using perchloric acid in acetic anhydride. The thiomethyl derivative as shown in formula 4 is deprotected as shown in Step (c), preferably using sodium thiomethoxide in polar solvents such as DMF at temperatures ranging from room temperature to 100° C. to give the corresponding thiol derivative as shown in formula 5.
Scheme VI
[0080] Step (a) involves the coupling of the acid derivative as shown in formula I with the acetyl hydrazine derivative in the presence of coupling agents such as CDI or EDAC, preferably CDI, in the presence of activating agents such as HOBt in polar solvents such as DMF to give hydrazide derivative as shown in formula 2.
[0081] Step (b) involves cyclization of the hydrazide derivative as shown in formula 2 to the corresponding oxadiazole derivative as shown in formula 3 via silylation of hydrazide derivative, preferably with hexamethyldisilazane, followed by cyclization involving desilylation in the presence of a base such as TBAF in a high boiling solvent such as chlorobenzene at temperatures ranging from room temperature to reflux, preferably at reflux.
[0082] Step (c) involves alkylation of the alkali metal salt such as sodium or potassium salt of the acid derivative as shown in formula 1 with alpha-bromo ketone derivative as shown in formula 4 in the presence of a base such as tetrabutylammonium bromide in a high boiling solvent such as toluene or chlorobenzene, preferably toluene. The ester is isolated by normal aqueous workup.
[0083] Step (d) involves cyclization of the ester as shown in formula 5 to the corresponding oxazole derivative as shown in formula 6 in the presence of a base like ammonium acetate in an acidic solvent such as acetic acid.
Scheme VII
[0084] Step (a) involves chlorination of the 5-carboxylic acid derivative of quinoxaline-2,3-dione as shown in formula 1 to the corresponding chloro derivative shown in formula 2, using chlorinating agents such as phosphoryl chloride or phosphous pentachloride or thionyl chloride, preferably a mixture of phosphoryl chloride and phosphorus pentachloride. The reaction is carried out at temperatures ranging between 80° C. to reflux, preferably reflux. Volatile material is evaporated and the reaction mixture quenched over ice followed by aqueous inorganic base workup using aqueous solution of sodium bicarbonate or sodium carbonate, preferably sodium bicarbonate. The product is isolated on adjusting the pH to 6 using acids such as acetic acid or HCl, preferably acetic acid.
[0085] Step (b) involves methoxylation of the 2,3-dichloroquinoxaline derivative as shown in formula 2 to the corresponding 2,3-dimethoxy compound as shown in formula 3. The reaction is carried out using an alkali metal alkoxide, preferably sodium methoxide, in hydroxylated solvent such as methanol at temperatures ranging from room temperature to reflux, preferably reflux, and product isolated by aqueous workup.
[0086] Step (c) involves chlorination of the 5-carboxylic acid derivative as shown in formula 3 to the corresponding acid chloride derivative as shown in formula 4 using chlorinating agents such as oxalyl chloride, thionyl chloride or phosphorus trichloride, preferably thionyl chloride at temperatures ranging from room temperature to reflux, preferably reflux.
[0087] Step (d) involves generation of the a-haloketone as shown in formula 5 from the 5-carboxylic acid chloride derivative as shown in formula 4 via a diazoketone generated by reacting the acid chloride with diazomethane. The diazoketone intermediate on treatment with acids like HBr or HCl, preferably HBr, gave the corresponding α-bromomethyl ketone as shown in formula 5.
[0088] Step (e) involves cyclization of the α-haloketone as shown in formula 5 to the corresponding imidazolyl derivative as shown in formula 7 by reacting the compound shown in formula 5 with an amidine derivative, preferably with benzhydrylamidine derivative as shown in formula 6 in a chlorinated solvent such as dichloromethane or chloroform, preferably chloroform ( Heterocycles, 1996;42:5 17).
[0089] Step (f) involves deprotection of the imino ether moieties in formula 7 to the corresponding amide derivative as shown in formula 8. The reaction is carried out using trimethylsilyl iodide or trimethylsilyl chloride/KI mixture or inorganic acids such as aqueous HCl or HBr, preferably 5N HCl at temperatures ranging from room temperature to 100° C., preferably 80° C.
Scheme VIII
[0090] Step (a) involves generation of the amide as shown in formula 2 from the acid chloride derivative as shown in formula 1 by reacting the acid chloride with ammonia in a sealed tube. The reaction is also carried out in an ethereal solvent such as dioxane or THF, preferably dioxane, and bubbling in gaseous ammonia.
[0091] Step (b) involves dehydration of the amide as shown in formula 2 to give the corresponding cyano derivative as shown in formula 3. The reaction is carried out using dehydrating agents such as polyphosphoric acid with or without a solvent.
[0092] Step (c) involves generation of the amidine derivative as shown in formula 4 by treating the cyano derivative as shown in formula 3 with hydroxylamine hydrochloride in the presence of an inorganic base such as potassium carbonate or sodium carbonate in an alcoholic solvent such as methanol or ethanol, preferably ethanol.
[0093] Step (d) involves cyclization of the amidine derivative as shown in formula 4 to the corresponding oxadiazole derivative as shown in formula 5 by reacting the amidine derivative with an acid chloride, preferably with acetyl chloride, in the presence of an organic base such as pyridine or triethylamine, preferably pyridine, using base as the solvent at temperatures ranging from room temperature to reflux, preferably reflux.
[0094] Step (e) involves the cleavage of the imino ether functionality as shown in formula 5 to the corresponding amide derivative as shown in formula 6. The cleavage is carried out in the presence of reagents such as trimethylsilyl iodide or trimethylsilyl chloride/KI, or inorganic acids such as HCl or HBr, preferably aqueous HCl
Scheme IX
[0095] Step (a) involves cyclization of the hydroxyamidine derivative as shown in formula 1 to the corresponding substituted oxadiazole derivative as shown in formula 2 by reacting the hydroxyamidine derivative with an acid chloride, preferably with trichloroacetylchloride, in the presence of an organic acid such as acetic acid or trichloroacetic acid, preferably trichloroacetic acid, at temperatures ranging from room temperature to reflux, preferably above 100° C., J. Med. Chem., 1994;37:2421.
[0096] Step (b) involves cyclization of the hydroxyamidine derivative as shown in formula 1 to the corresponding oxadiazoline derivative as shown in formula 3 by reacting the hydroxyamidine derivative with a reactive bifunctional acylating agent such as ethyl chloroformate or phosgene, preferably ethyl chloroformate, in the presence of inorganic bases such as potassium carbonate in polar solvents such as acetone at temperatures ranging from room temperature to reflux, preferably reflux. Alternatively, the cyclization can be carried out by reacting hydroxyamidine derivative with diethyl carbonate in the presence of alkali metal bases such as sodium or potassium ethoxide in an alcoholic solvent such as ethanol at temperatures ranging from room temperature to reflux, preferably reflux.
[0097] Step (c) involves cleavage of the imino ethers in compounds shown in formula 2 or 3 to give the corresponding amide derivatives as shown in formula 4. The deprotection can be carried out in the presence of silyl agents such as trimethylsilyl iodide or trimethylsilyl chloride/KI mixture or in the presence of inorganic acids such as aqueous HCl or HBr.
Scheme X
[0098] Step (a) involves the cyclization of the amide derivative as shown in formula 1 to the corresponding oxadiazole derivative as shown in formula 2 by reacting the amide initially with a diketo compound such as dimethylacetamide dimethyl acetal to give the corresponding acylamidine derivative in situ. The acylamidine derivative on treatment with hydroxylarnine hydrochloride in the presence of inorganic bases such as sodium bicarbonate or sodium hydroxide or sodium acetate, preferably sodium hydroxide, in an aqueous solution, gave the cyclized product as shown in formula 2.
[0099] Step (b) involves the cleavage of the imino ethers in compound shown in formula 2 to the corresponding amide derivative as shown in formula 3 using conditions described in Scheme IX, Step (c).
Scheme XI
[0100] Step (a) involves the generation of the aminoamidinyl intermediate as shown in formula 2 from the 5-cyano-2,3-dimethoxy-quinoxaline derivative as shown in formula 1 by treating the cyano derivative with hydrazine in the presence of a base like sodium hydride using ethereal solvent such as THF or dioxane, preferably THF. The reaction can be carried out at temperatures ranging from room temperature to reflux, preferably reflux.
[0101] Step (b) involves cyclization of the aminoamidine derivative as shown in formula 2 to the corresponding thiadiazole derivative as shown in formula 3 by treating compound 2 with carbon disulfide at temperatures ranging from room temperature to reflux, preferably reflux.
[0102] Step (c) involves deprotection of the imino ethers in compound shown in formula 3 using conditions described in Scheme IX, Step (c).
Scheme XII
[0103] Step (a) involves the formation of the tetrazole derivative as shown in formula 2 by reacting the corresponding cyano derivatives as shown in formula 1 with tri-n-butyltin azide in an ethereal solvent such as dioxane or THF, preferably dioxane, at temperatures ranging from room temperature to reflux preferably around 60° C.
[0104] Step (b) involves deprotection of the imino ethers in compound shown in formula 2 using conditions discussed in Scheme IX, Step (c) to give the amide derivative shown in formula 3.
Scheme XIII
[0105] Step (a) involves the chlorination of the quinoxaline-2,3-dione derivative as shown in formula 1 to the corresponding 2,3-dichloro derivative as shown in formula 2 using conditions discussed in Scheme VII, Step (a).
[0106] Step (b) involves methoxylation of the dichloro derivative shown in formula 2 to the corresponding 2,3-dimethoxy compound as shown in formula 3 using alkali metal alkoxide, preferably sodium methoxide, in alcoholic solvent such as methanol at temperatures ranging from room temperature to reflux, preferably reflux.
[0107] Step (c) involves reduction of the ester moiety in the compound shown in formula 3 to the corresponding hydroxymethyl derivative shown in formula 4 using a borohydride reagent, preferably lithium borohydride, in an alcoholic solvent, preferably ethanol, at temperatures ranging from room temperature to 50° C., preferably room temperature.
[0108] Step (d) involves bromination of the hydroxymethyl derivative shown in formula 4 using brominating agents such as HBr or phosphorus tribromide or thionyl bromide, preferably HBr, in solvents such as acetic acid.
[0109] Step (e) involves converting the bromomethyl derivative to the corresponding cyanomethyl derivative as shown in formula 5 using alkali metal cyanide, preferably potassium cyanide, in polar solvents such as DMSO or DMF, preferably DMSO.
[0110] Step (f) involves a cycloaddition reaction involving the cyanomethyl derivative shown in formula 5 with a dipolarophile such as tri-n-butyltin azide to give the tetrazole derivative as shown in formula 6. The reaction can be carried out as described in Scheme XII, Step (a).
[0111] Step (g) involves deprotection of the imino ethers as shown in formula 6 to the corresponding amide derivative as shown in formula 7 as described in Scheme IX, Step (c).
Scheme XIV
[0112] Step (a) involves alkylation of the bromomethyl derivative shown in formula I with diethylacetamidomalonate sodium salt, generated by treating diethylacetamidomalonate with sodium hydride in an ethereal solvent such as THF or polar solvent such as DMF to give the amino acid precursor, which on treatment with a base such as aqueous sodium hydroxide in alcoholic solvent such as ethanol gave the desired N-acetyl-amino acid derivative as shown in formula 2.
[0113] Step (b) involves cyclization of the amino acid intermediate as shown in formula 2 to the corresponding oxazolidinone derivative as shown in formula 3 by treating the amino acid intermediate with formaldehyde in acidic solvent such as acetic acid in the presence of catalytic p-toluenesulfonic acid. On aqueous workup, the desired oxazolidinone is obtained (Walter M. W., et al., Tetrahedron Letters, 1995;36:7761).
[0114] Step (c) involves the optional resolution step of the stereoisomers of the amino acid derivative shown in formula 2. The resolution is carried out by using hog kidney acylase in aqueous solution at pH 7.5. The D-isomer is isolated and crystallized. The optically pure amino acid derivative, as shown in formula 2a, can also be used to synthesize the oxazolidinone derivative shown in formula 3 as a single enantiomer.
[0115] Step (d) involves deprotection of the imino ethers as shown in formulas 2a and 4 to the corresponding amide derivatives as shown in formulas 4 and 4a. The deprotection can be carried out as described in Scheme IX, Step (c).
Scheme XV
[0116] Step (a) involves the reaction of the organomagnesium salt of 2-bromo-3-nitrotoluene as shown in formula 1, prepared by the reaction of compound I and fresh magnesium turnings in ether, with an amino ketone such as 1-methyl-3-piperidone derivative in an ethereal solvent such as diethyl ether or THF or dioxane. The reaction mixture is quenched with aqueous ammonium chloride solution (Step b), and the crude product is heated to about 100° C. with a protic solvent such as acetic acid or HCl. The tetrahydropyridinyl derivative as shown in formula 2 is isolated as a free base on quenching the reaction with saturated sodium bicarbonate or ammonia solution.
[0117] Step (c) involves the reduction of the tetrahydropyridinyl derivative as shown in formula 2 to give the corresponding piperidinyl derivative as shown in formula 3. The reduction is carried out under catalytic hydrogenation conditions using Pd/C (5% to 20%), preferably 20%, and hydrogen gas at 50 psi in a hydroxylated solvent such as methanol.
[0118] Step (d) involves acetylation of the amino group in compound shown in formula 3 followed by nitration and deprotection to give the nitroaniline derivative as shown in formula 4. The acetylation is carried out by heating the solution of compound 3 in acetic anhydride to reflux or by treating a solution of compound 3 in a solvent such as dichloromethane or THF, preferably dichloromethane with acetyl chloride in the presence of a base such as triethylamine or pyridine and a catalytic amount of DMAP. In the case of pyridine as the base, the amine is dissolved in pyridine. The nitration is carried out using nitrating mixtures such as potassium nitrate and sulfuric acid or nitric acid in acetic anhydride, preferably nitric acid in acetic anhydride. Removal of the acetyl group is done by treatment with an inorganic base such as sodium hydroxide in hydroxylated solvent such as methanol or water.
[0119] Step (e) involves reduction of the o-nitroaniline derivative as shown in formula 4 to the corresponding o-phenylenediamine intermediate as shown in formula 5. The reduction is carried out under catalytic hydrogenation conditions using Raney Nickel or Pd/C as the catalysts and hydrogen gas under pressures of up to 50 psi in alcoholic solvents such as methanol. The reduction is also carried out under metal/acid conditions such as Fe/HCl or Sn/HCl, preferably Fe/HCl.
[0120] Step (f) involves formation of quinoxaline-2,3-dione derivative as shown in formula 6 by reacting the o-phenylenediamine derivative shown in formula 5 with an alpha-dicarbonyl derivative such as oxalyl chloride or dimethyl oxalate or oxalic acid, preferably dimethyl oxalate, in an ethereal solvent such as THF or protic solvent such as methanol or aqueous HCl, preferably THF.
[0121] Step (g) involves nitration of the quinoxaline-2,3-dione derivative shown in formula 6 to give the corresponding nitro derivative as shown in formula 7 using reagents such as KNO 3 /H 2 SO 4 or HNO 3 or nitronium tetrafluoroborate, preferably KNO 3 /H 2 SO 4 .
Scheme XVI
[0122] Step (a) involves protection of the amino group of the aniline derivative as shown in formula 1. The preferred protecting group is Boc and is incorporated by treating the aniline derivative with Boc anhydride in the presence of an aqueous base such as sodium hydroxide or sodium carbonate, preferably sodium carbonate.
[0123] Step (b) involves the coupling of 2-chloropyridine with the N-Boc aniline derivative in the presence of a base such as n-BuLi in an ethereal solvent such as anhydrous THF. The coupling is carried out at temperatures ranging from 0° C. to room temperature to give the product as shown in formula 2.
[0124] Step (c) involves reduction of the pyridyl ring in the compound shown in formula 2 to give the corresponding reduced compound as shown in formula 3. Initially, the pyridinyl moiety is quatemized with an alkylating agent such as methyl iodide or methyl triflate, preferably methyl iodide, in the presence of solvent such as THF or methanol. The quaternary salt is then reduced to the tetrahydro stage using borohydride reducing agents such as sodium borohydride or sodium cyanoborohydride, preferably sodium borohydride, in solvents such as ethanol. The tetrahydropyridyl ring is fully reduced to the piperidinyl ring via catalytic hydrogenation using Pd/C as the catalyst and hydrogen gas (up to 50 psi) in solvents such as THF or ethanol.
[0125] Step (d) involves nitration of the piperidinyl compound shown in formula 3 to give the corresponding nitroaniline derivative as shown in formula 4. The nitration is carried out using conditions described in Step (d) of Scheme XV.
[0126] Step (e) involves reduction of the nitroaniline derivative shown in formula 4 to the corresponding o-phenylenediamine derivative as shown in formula 5. The reduction is carried out as described in Step (e) in Scheme XV.
[0127] Step (f) involves formation of the quinoxaline-2,3-dione derivative as shown in formula 6 by reacting oxalic acid derivative with the o-phenylenediamine as shown in formula 5. The reaction conditions are described in Step (f), Scheme XV.
[0128] Step (g) involves nitration of the quinoxaline-2,3-dione derivative as shown in formula 6 to give the corresponding nitro derivative as shown in formula 7. The reaction conditions are described in Step (g) in Scheme XV.
Scheme XVII
[0129] Step (a) involves Pd catalyzed coupling of bromobenzene derivative shown in formula 1 with 2-lithio-N-Boc-pyrrolidino or N-Boc-piperidino compound as shown in formula 2 generated in situ by reacting N-Boc pyrrolidine or piperidine with sec-BuLi in a solvent such as THF to give the corresponding cyclic amine derivative as shown in formula 2. The reaction is carried out as reported in the literature by Dieter, et al., Tetrahedron Letters, 1995;36:3613-3616. The reaction is carried out in the presence of catalytic amounts of CuCN and Pd[(p-OCH 3 -Ph) 3 P] 4 or PdCl 2 (PPh 3 ) 2 .
[0130] Step (b) involves nitration of the aniline derivative shown in formula 2 to give the corresponding o-nitroaniline derivative as shown in formula 3. The conditions for nitration are described in Step (d), Scheme XV.
[0131] Step (c) and (d) involve the reduction of the o-nitroaniline derivative to the corresponding o-phenylenediamine derivative as shown in formula 3 and cyclization of the o-phenylenediamine derivative as shown in formula 4 to the corresponding quinoxaline-2-3-dione derivative as shown in formula 5, respectively. The conditions for both these steps have been described in Steps (e) and (f) of Scheme XV, respectively.
[0132] Step (e) involves nitration of the quinoxaline-2,3-dione derivative as shown in formula 5 to the corresponding nitro derivative as shown in formula 6. The conditions for the nitration are described in Step (g) of Scheme XV.
Scheme XVIII
[0133] Step (a) involves coupling of the bromobenzene derivative as shown in formula 1 with amino acid chloride as shown in formula 2 via generation of the organomagnesium salt using fresh magnesium turnings in a solvent such as ether. The ketone derivative as shown in formula 3 is isolated on quenching the reaction with aqueous ammonium chloride followed by normal aqueous workup (Macor J. E., et al., J. Organic Chem., 1994;59:7496).
[0134] Step (b) involves the reduction of the nitro group of the nitrobenzene derivative as shown in formula 3 under catalytic hydrogenation conditions to give the corresponding aniline derivative as shown in formula 4. The preferred catalyst is Raney Nickel, and the solvent is preferably methanol and hydrogen gas at around 50 psi.
[0135] Steps (c) and (d) involve acetylation of the aniline derivative as shown in formula 4 followed by nitration to give the o-nitroaniline derivative as shown in formula 5. The conditions for acetylation and nitration are described in Step (d) of Scheme XV.
[0136] Step (e) involves deprotection of the amino group and reduction of the keto nitroaniline derivative as shown in formula 5 to the corresponding o-phenylenediamine derivative as shown in formula 6. The acetyl group is saponified using an aqueous base such as sodium or potassium hydroxide, preferably sodium hydroxide. The reduction is carried out using LAH as a reducing agent in an ethereal solvent such as anhydrous THF. Alternatively, the keto group can be reduced under Wolff-Kishner conditions, i.e., via the hydrazone formation followed by the catalytic (Ra—Ni) reduction of the nitro group.
[0137] Steps (f) and (g) involve the formation of the quinoxaline-2,3-dione derivative followed by nitration of the quinoxaline-2,3-dione derivative as shown in formula 7 from the o-phenylenediamine derivative as shown in formula 6. The conditions for the quinoxaline-2,3-dione formation and nitration are described in Steps (f) and (g) of Scheme XV.
Scheme XIX
[0138] Step (a) involves formation of the benzyl bromide derivative as shown in formula 2 from the benzyl alcohol derivative as shown in formula 1 from the benzylalcohol derivative as shown in formula 1. The bromination is carried out using brominating agents such as phosphorus tribromide, thionyl bromide or CBr 4 /PPh 3 , preferably CBr 4 /PPh 3 , in an ethereal solvent such as ether or THF, preferably ether.
[0139] Step (b) involves alkylation of the N-Boc imidazolone derivative as shown in formula 3 with the benzyl bromide derivative as shown in formula 2. The reaction involves generation of an anion using a lithium base such as LDA in ethereal solvent such as THF followed by addition of the benzyl bromide solution (Harding M. M., et al., Tetrahedron Asymmetry, 1994;5:1793-1804).
[0140] Steps (c) and (d) involve reduction of the o-nitroaniline derivative as shown in formula 4, followed by the cyclization of the o-phenylenediamine derivative to the corresponding quinoxaline-2,3-dione derivative as shown in formula 5. The conditions for reduction and cyclization are described in Steps (e) and (f) of Scheme XV, respectively.
[0141] Step (e) involves the nitration of the quinoxaline-2,3-dione derivative and simultaneous hydrolytic ring opening of the imidazolone side-chain as shown in formula 5 to the corresponding 7-nitro-quinoxaline-2,3-dione derivative as shown in formula 6. The conditions for nitration are described in Step (g) of Scheme XV.
Scheme XX
[0142] Step (a) involves alkylation of the anion of 2,3-diethoxy pyrazine (Schollkopf chiral auxiliary) derivative as shown in formula 2 with benzyl bromide derivative as shown in formula 1. The anion is generated using a lithium base, preferably n-BuLi, and the reaction can be carried out as described earlier by Cook, et al., Synthetic Communications, 1995;25:3883-3900 to give the product as shown in formula 3.
[0143] Steps (b) and (c) involve reduction of the o-nitroaniline derivative as shown in formula 2 to the o-phenylenediamine derivative and formation of the corresponding quinoxaline-2,3-dione derivative as shown in formula 4, respectively. The conditions for reduction and cyclization are described in Steps (e) and (f) in Scheme XV, respectively.
[0144] Step (d) involves the nitration of the quinoxaline-2,3-dione derivative as shown in formula 3 to the corresponding 7-nitro derivative as shown in formula 4. During nitration the 2,5-diethoxypyrazine side-chain is hydrolyzed to give the amino acid side-chain as shown in formula 5. The conditions for nitration are as described in Step (g) of Scheme XV.
[0145] The aforementioned abbreviations have the following meanings:
[0146] Boc tertiary Butyloxycarbonyl
[0147] CDI 1,1′-Carbonyldimidazole
[0148] CBZ Benzyloxycarbonyl
[0149] DEAD Diethyl azodicarboxylate
[0150] DEE Diethyl ether
[0151] DMAP 4-Dimethylaminopyridine
[0152] DMF Dimethylformamide
[0153] DMSO Dimethyl sulfoxide
[0154] EDAC Ethyl-3-(3-dimethylamino)-propylcarbodiimide
[0155] FMOC 9 -Fluorenylmethyloxycarbonyl
[0156] HOBt 1-Hydroxybenzotriazole
[0157] LAH Lithium Aluminum Hydride
[0158] NMP n-Methyl pyrrolidone
[0159] TEA Triethylamine
[0160] TFA Trifluoroacetic acid
[0161] THF Tetrahydrofuran
[0162] Some preferred compounds are shown below. The compounds are preferably NO 2 derivatives for R 4 .
[0163] wherein Y is oxygen or sulfur.
[0164] Some of the compounds of Formula I are capable of further forming both pharmaceutically acceptable acid addition and/or base salts. These forms are within the scope of the present invention.
[0165] Pharmaceutically acceptable acid addition salts of the compounds of Formula I include salts derived from nontoxic inorganic acids such as hydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydriodic, hydrofluoric, phosphorous, and the like, as well as the salts derived from nontoxic organic acids, such as aliphatic mono- and bicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids, alkanedioic acids, aromatic acids, aliphatic and aromatic sulfonic acids, etc. Such salts thus include sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, nitrate, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, acetate, trifluoroacetate, propionate, caprylate, isobutyrate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, mandelate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, phthalate, benzenesulfonate, toluenesulfonate, phenylacetate, citrate, lactate, maleate, tartrate, methanesulfonate, and the like. Also contemplated are salts of amino acids such as arginate and the like and gluconate, galacturonate (see, for example, Berge S. M., et al., “Pharmaceutical Salts,” J. Pharma. Sci., 1977;66:1).
[0166] The acid addition salts of said basic compounds can be prepared by contacting the free base form with a sufficient amount of the desired acid to produce the salt in the conventional manner. The free base form may be regenerated by contacting the salt form with a base and isolating the free base in the conventional manner. The free base forms differ from their respective salt forms somewhat in certain physical properties such as solubility in polar solvents, but otherwise the salts are equivalent to their respective free base for purposes of the present invention.
[0167] Pharmaceutically acceptable base addition salts can be formed with metals or amines, such as alkali and alkaline earth metals or organic amines. Examples of such metals used as cations are sodium, potassium, magnesium, calcium, and the like. Examples of suitable amines are N,N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, dicyclohexylamine, ethylenediamine, N-methylglucamine, and procaine (see Berge, Supra, 1977).
[0168] The base addition salts of said acidic compounds can be prepared by contacting the free acid form with a sufficient amount of the desired base to produce the salt in the conventional manner. The free acid form may be regenerated by contacting the salt form with an acid and isolating the free acid in the conventional manner. The free acid forms differ from their respective salt forms somewhat in certain physical properties such as solubility in polar solvents, but otherwise the salts are equivalent to their respective free acid for purposes of the present invention.
[0169] Certain of the compounds of the present invention can exist in unsolvated forms as well as solvated forms, including hydrated forms and are intended to be encompassed within the scope of the present invention.
[0170] Certain of the compounds of the present invention possess one or more chiral centers and each center may exist in the R(D) or S(L) configuration. The present invention includes all enantiomeric and epimeric forms as well as the appropriate mixtures thereof.
[0171] In the compounds of Formula I the amino acid derivative is an ester, an amide, a hydrazide, or a semicarbazide. The term “alkyl” means a straight or branched hydrocarbon radical having from 1 to 6 carbon atoms and includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, and the like.
[0172] The term “carboxyalkyl” means alkyl as above and attached to a carboxy group.
[0173] The term “phosphoroalkyl” means alkyl as above and attached to a phosphoro group.
[0174] The term “phosphonoalkyl” means alkyl as above and attached to a phosphono group.
[0175] The term “alkenyl” means a straight or branched unsaturated hydrocarbon radical having from 3 to 6 carbon atoms and includes, for example, 2-propenyl, 1-butenyl, 2-butenyl, 1-pentenyl, 2-pentenyl, 3-methyl-3-butenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, and the like.
[0176] “Alkoxy” or “thioalkoxy” is O-alkyl or S-alkyl of from 1 to 6 carbon atoms as defined above for “alkyl”.
[0177] The term “aryl” means an aromatic radical which is a phenyl group, a phenyl group substituted by 1 to 4 substituents selected from alkyl as defined above, alkoxy as defined above, thioalkoxy as defined above, hydroxy, halogen, trifluoromethyl, amino, alkylamino as defined above for alkyl, dialkylamino as defined for alkyl, or 1,3-benzodioxol-5-yl.
[0178] The term “aralkyl” means aryl and alkyl as defined above and includes but is not limited to benzyl, 2-phenylethyl, and 3-phenylpropyl; a preferred group is phenyl.
[0179] The term “heteroaryl” means a heteroaromatic radical which is 2-, 3-, or 4-pyridinyl, 2-, 4-, or 5-pyrimidinyl, 2- or 3-thienyl, isoquinolines, quinolines, imidazolines, pyrroles, indoles, and thiazoles.
[0180] “Halogen” is fluorine, chlorine, bromine, or iodine.
[0181] The term “haloalkyl” means halogen and alkyl as defined above, for example, but not limited to, trifluoromethyl and trichloromethyl.
[0182] “Alkylaryl” means aryl as defined above and alkyl as defined above, for example, but not limited to benzyl, 2-phenylethyl, 3-phenylpropyl; a preferred group is benzyl.
[0183] The term “heterocycloalkyl” means a nonaromatic ring with from 4 to 7 members, with up to 4 heteroatoms for example, N, O, and S.
[0184] Common amino acid moiety means the naturally occurring I-amino acids, unnatural amino acids, substituted Θ, K, Λ amino acids and their enantiomers.
[0185] Common amino acids are: Alanine, Θ-alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.
[0186] Modified and unusual amino acids are as would occur to a skilled chemist and are, for example, but not limited to:
[0187] 10,11-Dihydro-5H-dibenzo[a,d]cyclohepten-5-yl)glycine or I-Amino-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-acetic acid (Para-phenyl)phenylalanine;
[0188] 3,3-Diphenylalanine;
[0189] 3-Hydroxyproline;
[0190] 4-Hydroxyproline;
[0191] N-Methylphenylalanine;
[0192] N-Methylaspartic acid;
[0193] N-Methylisoleucine;
[0194] N-Methylvaline;
[0195] Norvaline;
[0196] Norleucine;
[0197] Omithine;
[0198] 2-Aminobutyric acid;
[0199] 2-Amino-4-pentanoic acid (Allylglycine);
[0200] N G -Nitroarginine;
[0201] 2-Amino-3-(2-amino-5-thiazole)propanoic acid;
[0202] 2-Amino-3-cyclopropanepropanoic acid (Cyclopropylalanine);
[0203] Cyclohexylalanine (Hexahydrophenylalanine);
[0204] N-Methylcyclohexylalanine (N-Methylhexahydro-phenylalanine);
[0205] 2-Amino-4,4(RS)-epoxy-4-pentanoic acid;
[0206] N im -2,4-Dinitrophenylhistidine;
[0207] 2-Aminoadipic acid;
[0208] 2-Amino-5-phenylpentanoic acid (Homophenylalanine);
[0209] Methionine sulfoxide;
[0210] Methionine sulfone;
[0211] 3-(1′-Naphthyl)alanine;
[0212] 3-(2′-Naphthyl)alanine;
[0213] 2-Amino-3-cyanopropanoic acid (Cyanoalanine);
[0214] Phenylglycine;
[0215] 2-Aminopentanoic acid (Propylglycine);
[0216] 2-Amino-6-(1-pyrrolo)-hexanoic acid;
[0217] 2-Amino-3-(3-pyridyl)-propanoic acid (3-Pyridylalanine);
[0218] 1,2,3,4-Tetrahydro-3-isoquinolinecarboxylic acid;
[0219] 2-Amino-3-(4-thiazolyl)-propanoic acid;
[0220] O-Tertiarybutyl-tyrosine;
[0221] O-Methyl-tyrosine;
[0222] O-Ethyl-tyrosine;
[0223] N in -Formyl-tryptophan;
[0224] 5H-Dibenzo[a,d]cycloheptenyl glycine;
[0225] 9H-Thioxanthenyl glycine; and
[0226] 9H-Xanthenyl glycine.
[0227] The compounds of the present invention can be prepared and administered in a wide variety of routes of administration such as parenteral, oral, topical, rectal, inhalation and the like. Formulations will vary according to the route of administration selected. Examples are oral and parenteral dosage forms. Thus, the compounds of the present invention can be administered by injection, that is, intravenously, intramuscularly, intracutaneously, subcutaneously, intraduodenally, or intraperitoneally. Also, the compounds of the present invention can be administered by inhalation, for example, intranasally. Additionally, the compounds of the present invention can be administered transdermally. The following dosage forms may comprise as the active component, a compound of Formula I or a corresponding pharmaceutically acceptable salt of a compound of Formula I.
[0228] For preparing pharmaceutical compositions from the compounds of the present invention, pharmaceutically acceptable carriers can be either solid or liquid. Solid form preparations include powders, tablets, pills, capsules, cachets, suppositories, and dispersible granules. A solid carrier can be one or more substances which may also act as diluents, flavoring agents, binders, preservatives, tablet disintegrating agents, or an encapsulating material.
[0229] In powders, the carrier can be a finely divided solid which is in a mixture with the finely divided active component.
[0230] In tablets, the active component can be mixed with the carrier having the necessary binding properties in suitable proportions and compacted in the shape and size desired.
[0231] The powders and tablets preferably contain from 5% or 10% to about 70% of the active compound. Suitable carriers are magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose, a low melting wax, cocoa butter, and the like. The term “preparation” is intended to include the formulation of the active compound with encapsulating material as a carrier providing a capsule in which the active component with or without other carriers, is surrounded by a carrier, which is thus in association with it. Similarly, cachets and lozenges are included. Tablets, powders, capsules, pills, cachets, and lozenges can be used as solid dosage forms suitable for oral administration.
[0232] For preparing suppositories, a low melting wax, such as a mixture of fatty acid glycerides or cocoa butter, is first melted and the active component can be dispersed homogeneously therein, as by stirring. The molten homogenous mixture can be then poured into convenient sized molds, allowed to cool, and thereby to solidify.
[0233] Liquid form preparations include solutions, suspensions, and emulsions, for example, water or water propylene glycol solutions. For parenteral injection, liquid preparations can be formulated in solution in aqueous polyethylene glycol solution.
[0234] Aqueous solutions suitable for oral use can be prepared by dissolving the active component in water and adding suitable colorants, flavors, stabilizing, and thickening agents as desired.
[0235] Aqueous suspensions suitable for oral use can be made by dispersing the finely divided active component in water with viscous material, such as natural or synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose, and other well-known suspending agents.
[0236] Also included are solid form preparations which are intended to be converted, shortly before use, to liquid form preparations for oral administration. Such liquid forms include solutions, suspensions, and emulsions. These preparations may contain, in addition to the active component, colorants, flavors, stabilizers, buffers, artificial and natural sweeteners, dispersants, thickeners, solubilizing agents, and the like.
[0237] The pharmaceutical preparation is preferably in unit dosage form. In such form the preparation is subdivided into unit doses containing appropriate quantities of the active component. The unit dosage form can be a packaged preparation, the package containing discrete quantities of preparation, such as packeted tablets, capsules, and powders in vials or ampoules. Also, the unit dosage form can be a capsule, tablet, cachet, or lozenge itself, or it can be the appropriate number of any of these in packaged form.
[0238] The quantity of active component in a unit dose preparation may be varied or adjusted for example from about 0.1 mg to 200 mg, preferably about 0.5 mg to 100 mg according to the particular application and the potency of the active component. The composition can, if desired, also contain other compatible therapeutic agents.
[0239] In therapeutic use as agents for the treatment of neurological disorders, the compounds utilized in the pharmaceutical methods of this invention can be administered at an initial dosage of about 0.01 mg to about 200 mg/kg daily. A daily dose range of about 0.01 mg to about 50 mg/kg is preferred. The dosages, however, may be varied depending upon the requirements of the patient, the severity of the condition being treated, and the compound being employed. Determination of the proper dosage for a particular situation is within the skill of the art. Generally, treatment is initiated with smaller dosages which are less than the optimum dose of the compound. Thereafter, the dosage is increased by small increments until the optimum effect under the circumstances is reached. For convenience, the total daily dosage may be divided and administered in portions during the day, if desired.
[0240] Having described the invention herein, listed below are preferred embodiment or working examples wherein all temperatures are degrees Centigrade and all parts are parts by weight unless otherwise indicated.
EXAMPLES
Example 1
[0241] Scheme I procedure is followed as indicated below:
[0242] 5-Methyl-isatoic Anhydride (2)
[0243] To an aqueous solution of anthranilic acid (100 g, 0.66 mol) and sodium carbonate (0.7 mol) a solution of phosgene in toluene (362 mL, 1.93 M, 0.7 mol) was added dropwise under vigorous stirring. The reaction becomes a suspension and is stirred for additional 8 hours and filtered. The residue was treated with aqueous Na 2 CO 3 and filtered. Washed with water (4×150 mL) and dried.
[0244] Yield: 88.4 g, 75.4%.
[0245] MS (CI) m/z=178 (M+1).
[0246] 6-Bromo-5-methyl-isatoic Anhydride (3)
[0247] To a suspension of 5-methyl-isatoic anhydride (9.2 g, 0.052 mol) in a mixture of glacial acetic acid (60 mL) and TFA (30 mL), bromine (9.9 g, 0.062 mol) was added under stirring at 5° C. Reaction mixture warmed to room temperature and stirred ˜5 hours. Poured in cold water and yellow ppt filtered and washed with water and dried. Yield: 12.09 g, 90%.
[0248] MS (CI) m/z=257 (M+1).
[0249] 6-Bromo-5-methyl-8-nitro-isatoic Anhydride (4)
[0250] To a solution of 6-bromo-5-methyl-isatoic anhydride (12.03 g, 0.047 mol) in sulfuric acid (80 mL), potassium nitrate (5.05 g, 0.05 mol) was added at room temperature under vigorous stirring. After stirring approximately 8 hours, reaction mixture was poured over ice. The aqueous suspension was stirred for 0.5 hour and filtered and washed with water (4×100 mL) and dried. Yield 10.8 g, 76%.
[0251] MS (CI) m/z=302 (M+1).
[0252] Methyl-2-amino-5-bromo-6-methyl-3-nitrobenzoate (5)
[0253] A mixture of 6-bromo-5-methyl-8-nitro-isatoic anhydride (17.48 g, 0.0580 mol) in MeOH (180 mL) was heated at reflux for 3 hours. After standing at 0° C. for 2 to 3 hours, the precipitated product (5) was collected and washed with MeOH. Yield 12.24 g, 73%.
[0254] 2,3-Diamino-6-methylbenzoate (6)
[0255] A mixture of methyl-2-amino-5-bromo-6-methyl-3-nitrobenzoate (5) (12.24 g, 0.0423 mol) and 20% Pd on C (1.0 g) in 1:1 MeOH:THF (400 mL) with triethylamine (5.9 mL, 0.042 mol) was hydrogenated for 2 hours under a hydrogen pressure of 50 psi. The catalyst was filtered off (celite), and the filtrate was concentrated. The residue was taken up in EtOAc, and the organic layer was washed with a minimal amount of water. The organic layer was dried over sodium sulfate, filtered, and concentrated to give 7.62 g (100%) product (6). MS (APCI) m/z =181 (M+1).
[0256] Synthesis of 6-Methyl-2,3-dioxo-1,2,3,4-tetrahydro-quinoxaline-5-carboxylic Acid, Methyl Ester (7)
[0257] A solution of 2,3-diamino-6-methylbenzoic acid, methyl ester (compound 6) (1.14 g, 6.35 mmol) and dimethyl oxalate (3.34 g, 28.5 mmol) in MeOH (30 mL) was refluxed for 6 days. Upon cooling to room temperature, the precipitated product was collected and washed with a small amount of MeOH to give 1.02 g (69%). MS (APCI) m/z=235 (M+1).
[0258] Synthesis of 6-Methyl-7-nitro-2,3-dioxo-1,2,3,4-tetrahydro-quinoxaline-5-carboxylic Acid, Methyl Ester (8)
[0259] To a solution of 6-methyl-2,3-dioxo-1,2,3,4-tetrahydro-quinoxaline-5-carboxylic acid, methyl ester (1.11 g, 4.74 mmol) in conc. H 2 SO 4 (15 mL) at room temperature was added in one portion with vigorous stirring potassium nitrate (0.529 g, 5.23 mmol). The reaction mixture was stirred for 23 hours and poured over ice. The precipitated product was thoroughly washed with water upon collection to give 1.28 g (97%).
[0260] MS (CI) m/z =280 (M+1).
[0261] Synthesis of 6-Methyl-7-nitro-2,3-dioxo-1,2,3,4-tetrahydro-guinoxaline-5-carboxylic Acid (9)
[0262] To a suspension of 6-methyl-7-nitro-2,3-dioxo-1,2,3,4-tetrahydro-quinoxaline-5-carboxylic acid, methyl ester (0.80 g, 2.87 mmol) in THF (50 mL) was added aqueous 1.0N NaOH (4.3 mL, 4.3 mmol), and the reaction mixture was refluxed for 23 hours. The product is precipitated upon acidification with conc. HCL and recrystallized from water to give 0.73 g (96%).
[0263] MS (APCI) m/z =266 (M++1).
[0264] 2,3-Dichloro-6-methyl-7-nitro-quinoxaline-5-carboxylic Acid Methyl Ester (10)
[0265] To a suspension of 6-methyl-7-nitro-2,3-dioxo-1,2,3,4-tetrahydro-quinoxaline-5-carboxylic acid methyl ester (8) (5.85 g, 0.021 mol) in anhydrous N,N-dimethylformamide (60 mL) under an atmosphere of nitrogen was added dropwise a 20% phosgene solution in toluene 34.03 mL (0.068 mol). During the course of addition a mild exotherm resulted, and all undissolved material went into solution. After addition was complete (approximately 10 minutes), the reaction mixture was stirred at room temperature for 22 hours and concentrated. The residue was triturated with methanol and an off-white crystalline solid precipitated, 5.98 g (90%), mp 155-157° C.; 1 H NMR (CDCl 3 ): δ 8.48 (s, 1H), 4.05 (s, 3H), 2.59 (s, 3H); MS (APCI): m/z 317 (M + +H) + , 315 (M−H) + .
[0266] Anal. Calcd. for C 11 H 7 Cl 2 N 3 O 4 : C, 41.80; H, 2.23; N, 13.29; Cl, 22.43. Found: C, 41.74; H, 2.04; N, 13.23; Cl, 22.15.
[0267] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic Acid Methyl Ester (11)
[0268] To a solution of sodium metal (washed with hexane) 119 mg (5.19 mmol) dissolved in anhydrous methanol (15 mL) under an atmosphere of nitrogen at room temperature was added portionwise 2,3-dichloro-6-methyl-7-nitro-quinoxaline-5-carboxylic acid methyl ester (10, caution: exothermic) 655 mg (2.07 mmol). After the addition was complete (approximately 3 minutes), the reaction mixture was stirred for 10 minutes and quenched with water. The off-white amorphous precipitate was washed with water and methanol upon collection, 554 mg (87%), mp 174-176° C.; 1 H NMR (CDCL 3 ): δ 8.39 (s, 1H), 4.16 (s, 3H), 4.14 (s, 3H), 4.04 (s, 3H), 2.60 (s, 3H); MS (APCI): m/z 308 (M+H).
[0269] Anal. Calcd. for C 13 H 13 N 3 O 6 : C, 50.82; H, 4.26; N, 13.68. Found: C, 50.65; H, 4.20; N, 13.39.
[0270] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic Acid (12)
[0271] To a suspension of 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid methyl ester (11) (1.61 g, 5.24 mmol) in THF 20 mL was added a solution of potassium hydroxide (85%) in 20 mL water (0.86 g, 13.09 mmol). After stirring at room temperature for 20 hours, all solid went into solution. The reaction was allowed to continue for an additional 7 hours and was then cooled to 0° (ice water bath). Acidification with aqueous 1.0 N hydrochloric acid produced a white, amorphous precipitate which was recrystallized from ethyl acetate to give 1.47 g (95%) product, mp 258-260° C.; 1 H NMR (DMSO-d 6 ): δ 12.37 (br s, 1H), 8.09 (s, 1H), 3.93 (s, 3H), 3.89 (s, 3H), 2.34 (s, 3H); MS (APCI): m/z 294 (M+H).
[0272] Anal. Calcd. for C 12 H 11 N 3 O 6 : C, 49.15; H, 3.78; N, 14.33. Found: C, 49.19; H, 3.53; N, 14.28.
[0273] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl Chloride (13)
[0274] A mixture of 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid (12) (500 mg, 1.70 mmol) in thionyl chloride (twice distilled over triphenyl phosphite) (25 mL) was heated at reflux for 20 hours. The reaction mixture was concentrated to an off-white solid which was purified by elution through a flash column (4:1 hexanes:ethyl acetate), 510 mg (96%), mp 162-164° C.; 1 H NMR (CDCl 3 ): δ 8.35 (s, 1H), 4.15 (s, 3H), 4.03 (s, 3H), 2.55 (s, 3H); MS: m/z 312 (M+H).
[0275] Anal. Calcd. for C 12 H 10 ClN 3 O 5 : C, 46.24; H, 3.23; N, 13.48. Found: C, 46.38; H, 3.32; N, 13.28.
[0276] [(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-amino]Acetic Acid Tert-butyl Ester (14a) (General Procedure for Synthesis of Compounds 14b-m)
[0277] To a mixture of glycine tert-butyl ester hydrochloride 104 mg (0.67 mmol) and triethylamine in 3 mL anhydrous tetrahydrofuran 0.26 mL (1.69 mmol) under an atmosphere of nitrogen was added dropwise a solution of 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 200 mg (0.64 mmol) in 7 mL anhydrous tetrahydrofuran at 0° C. After the addition was complete (approximately 5 minutes), the reaction mixture was stirred at room temperature for 24 hours, filtered, and concentrated. The residue was taken up in ethyl acetate and the organic solution was washed with water, saturated aqueous sodium chloride, dried over sodium sulfate, filtered and concentrated. The crude product was purified by elution through a flash column (silica gel 60, 230-400 mesh, 3:2 hexanes/ethyl acetate) to give a yellow oil which crystallized on standing, 200 mg (77%), mp 125-126C; 1 H NMR (CDCl 3 ): δ 8.32 (s, 1H, 8-H), 6.32 (br s, 1H, amide NH), 4.14 (d, 2H, J=5.1 Hz), 4.09 (s, 3H), 3.99 (s, 3H), 2.54 (s, 3H), 1.47 (s, 9H, tert-butyl protons); MS (APCI): m/z 407 (M+H).
[0278] Anal. Calcd. for C 18 H 22 N 4 O 7 : C, 53.20; H, 5.46; N, 13.79. Found: C, 53.24; H, 5.45; N, 13.55.
[0279] [(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-methylamino]-acetic Acid, Tert-butyl Ester (14b)
[0280] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 200 mg (0.64 mmol) and sarcosine tert-butyl ester hydrochloride 122 mg (0.67 mmol). Reaction was continued for 24 hours, and the crude product was eluted through a flash column (4:1 hexanes:ethyl acetate), 200 mg (74%), mp 102-105° C.; 1 H NMR (CDCl 3 ): δ 8.29 (s, 1H), 4.27 (br s, 2H), 4.02 (s, 3H), 3.96 (s, 3H), 3.35 (br s, 3H), 2.54 (s, 3H), 1.41 (s, 9H); MS (APCI): m/z 421 (M+H).
[0281] Anal. Calcd. for C 19 H 24 N 4 O 7 : C, 54.28; H, 5.75; N, 13.33. Found: C, 54.51; H, 5.76; N, 13.35.
[0282] 3-[(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-amino]-propionic Acid, Tert-butyl Ester (14c)
[0283] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and β-alanine tert-butyl ester hydrochloride 153 mg (0.80 mmol). Reaction was continued for 2.5 hours, and the crude product was eluted through a flash column (3:2 hexanes:ethyl acetate), 230 mg (68%), mp 140-142° C., R f 0.47 (1:1 hexanes:ethyl acetate); 1 H NMR (CDCl 3 ): δ 8.31 (s, 1H), 6.37 (br s, 1H), 4.08 (s, 3H), 3.97 (s, 3H), 3.74 (q, 2H, methylene protons, J=6.1 Hz), 2.57 (t, 2H, J=6.3 Hz, J=6.1 Hz), 2.55 (s, 3H), 1.42 (s, 9H); MS (APCI): m/z 421 (M+H).
[0284] Anal. Calcd. for C 19 H 24 N 4 O 7 : C, 54.28; H, 5.75; N, 13.33. Found: C, 54.25; H, 5.69; N, 13.00.
[0285] (S)-2-[(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-amino]-3-phenylpropionic Acid, Tert-buyl Ester (14d)
[0286] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 200 mg (0.64 mmol) and L-phenylalanine, tert-butyl ester hydrochloride 173 mg (0.67 mmol). Reaction was continued for 24 hours, and the crude product was eluted through a flash column (4:1 hexanes:ethyl acetate), 180 mg (57%), mp 86-88° C.; 1 H NMR (CDCl 3 ): δ 8.32 (s, 1H), 7.22 (m, 5H), 6.39 (d, 1H, J=6.6 Hz), 4.88 (q, 1H, J=6.1, J=6.8 Hz), 4.07 (s, 3H), 4.00 (s, 3H), 3.23 (d, 2H, J=5.9 Hz), 2.56 (s, 3H), 1.37 (s, 9H); MS (APCI): m/z 497 (M+H).
[0287] Anal. Calcd. for C 25 H 28 N 4 O 7 : C, 60.48; H, 5.68; N, 11.28. Found: C, 59.73; H, 5.53; N, 11.28.
[0288] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic Acid Dimethylamide (14e)
[0289] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and an excess of a solution of gaseous dimethylamine bubbled into anhydrous THF. Reaction was continued for 19 hours, and the crude product was eluted through a flash column (7:3 hexanes:ethyl acetate), 260 mg (100%), mp 138-141° C.; 1 H NMR (CDCl 3 ): δ 8.29 (s, 1H, 8-H), 4.03 (s, 3H, OCH 3 ), 3.96 (s, 3H, OCH 3 ), 3.28 (s, 6H, N(CH 3 ) 2 ), 2.54 (s, 3H, 6-CH 3 ); MS (APCI): m/z 321 (M+H).
[0290] Anal. Calcd. for C 14 H 16 N 4 O 5 : C, 52.50; H, 5.03; N, 17.49. Found: C, 52.54; H, 5.01;N, 17.30.
[0291] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic Acid methyamide (14f)
[0292] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and an excess of a solution of gaseous monomethylamine bubbled into anhydrous THF. Reaction was continued for 17 hours, and the crude product was eluted through a flash column (11:9 hexanes:ethyl acetate), 190 mg (76%), mp 205-206° C.; 1 H NMR (CDCl 3 ): δ 8.32 (s, 1H), 5.83 (br s, 1H), 4.07 (s, 3H), 3.98 (s, 3H), 3.07 (d, 3H, J=5.1 Hz), 2.56 (s, 3H); MS (APCI): m/z 307 (M+1).
[0293] Anal. Calcd. for C 13 H 14 N 4 O 5 : C, 50.98; H, 4.61; N, 18.29. Found: C, 51.12; H, 4.72; N, 18.25.
[0294] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic Acid Benzylamide (14g)
[0295] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and benzylamine 90 11 L (0.84 mmol). Reaction was continued for 24 hours, and the crude product was eluted through a flash column (7:3 hexanes:ethyl acetate), 260 mg (84%), mp 171-173° C.; 1 HNMR (CCl 3 ): δ 8.32 (s, 1H), 7.32 (m, 5H), 6.12 (br s, 1H), 4.68 (d, 2H, J=5.6 Hz), 4.06 (s, 3H), 3.92 (s, 3H), 2.56 (s, 3H); MS (APCI): m/z 383 (M+1).
[0296] Anal. Calcd. for C 19 H 18 N 4 O 5 : C, 59.68; H, 4.74; N, 14.65. Found: C, 59.63; H, 4.94; N, 14.56.
[0297] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic Acid, 4-methoxy-benzylamide (14h)
[0298] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and 4-methoxybenzylamine 0.11 mL (0.84 mmol). Reaction was continued for 16 hours, and the crude product was recrystallized from hexanes:ethyl acetate to give yellow needles, 156 mg (47%), mp 187-189° C.; 1 HNMR (CDCl 3 ): δ 8.32 (s, 1H, 8-H), 7.28 (d, 2H, J=8.5 Hz), 6.85 (d, 2H, J=8.5 Hz), 6.07 (bs, 1H), 4.61 (d, 2H, J=5.6 Hz), 4.05 (s, 3H), 3.97 (s, 3H), 3.76 (s, 3H), 2.56 (s, 3H); MS (APCI): m/z 413 (M+1).
[0299] Anal Calcd. for C 20 H 20 N 4 O 6 : C, 58.25; H, 4.89; N, 13.59. Found: C, 58.55; H, 4.85; N, 13.47.
[0300] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-Carboxylic Acid Phenylamide (14i)
[0301] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and aniline 80 1 L (0.84 mmol). Reaction was continued for 40 hours, and the crude product was eluted through a flash column (3:2 hexanes:ethyl acetate), 180 mg (62%), mp 238-240° C.; 1 H NMR (CDCl 3 ): δ 8.34 (s, 1H), 7.81 (d, 2H, J=8.8 Hz), 7.69 (s, 1H), 7.35 (t, 2H, J=7.6, 8.5 Hz), 7.11 (t, 1H, J=6.3, J=7.3 Hz), 4.17 (s, 3H), 4.02 (s, 3H), 2.58 (s, 3H); MS (APCI): m/z 369 (M+H).
[0302] Anal. Calcd. for C 18 H 16 N 4 O 5 : C, 58.69; H, 4.38; N, 15.21. Found: C, 58.62; H, 4.52; N, 15.06.
[0303] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic Acid (4-methoxyphenyl) Amide (14j)
[0304] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and 4-anisidine 207 mg (1.68 mmol). Reaction was continued for 24 hours, and the crude product was eluted through a flash column (3:2 hexanes:ethyl acetate), 210 mg (66%), mp 206-208° C.; 1 H NMR (CDCl 3 ): δ 8.33 (s, 1H), 7.71 (d, 2H, J=9.0 Hz), 7.60 (s, 1H), 6.88 (d, 2H, J=8.8 Hz), 4.16 (s, 3H), 4.00 (s, 3H), 3.79 (s, 3H), 2.57 (s, 3H); MS (APCI): m/z 399(M+H).
[0305] AnaL Calcd. for C 19 H 18 N 4 O 6 : C, 57.29; H, 4.55; N, 14.06. Found: C, 57.23; H, 4.73; N, 14.01.
[0306] (2,3-Dimethoxy-6-methyl-7-nitro-quinoxalin-5-yl)-piperazin-1-yl Methanone (14k)
[0307] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and piperazine 138 mg (1.60 mmol). Reaction was continued for 2 hours, and the crude product was eluted through a flash column (8% methanol in chloroform): 250 mg (86%), mp 150-152° C.; 1 H NMR (CDCl 3 ): δ 8.30 (s, 1H), 4.05 (s, 3H), 3.96 (s, 3H), 3.81 (t, 4H, J=4.9, 5.1 Hz), 2.96 (t, 4H, J=5.1, 4.9 Hz), 2.54 (s, 3H), 1.84 (br s, 1H); MS (APCI): m/z 362 (M+H).
[0308] Anal. Calcd. for C 16 H 19 N 5 O 5 : C, 53.18; H, 5.30; N, 19.38. Found: C, 53.08; H, 5.22; N, 18.82.
[0309] [1,4]Diazepan-1-yl-(2,3-dimethoxy-6-methyl-7-nitro-quinoxalin-5-yl)methanone (14l)
[0310] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and homopiperazine 160 mg (1.60 mmol). Reaction was continued for 30 hours, and the crude product was eluted through a flash column (8% methanol in chloroform), 260 mg (87%), mp 141-143° C.; 1 H NMR (CDCl 3 ): δ 8.29 (s, 1H), 4.03 (s, 3H), 3.93 (br s, 7H), 3.02 (br s, 2H), 2.82 (t, 2H, J=5.4, J=5.6 Hz), 2.54 (s, 3H), 1.88 (t, 2H, J=5.6, 5.4 Hz), 1.79 (bs, 1H); MS (APCI): m/z 376 (M+H).
[0311] Anal. Calcd. for C 17 H 21 N 5 O 5 : C, 54.39; H, 5.64; N, 18.66. Found: C, 54.07; H, 5.57; N, 18.24.
[0312] 2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carboxylic acid, p-tolylamide (14m)
[0313] Prepared from 2,3-dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl chloride (13) 250 mg (0.80 mmol) and p-toluidine 180 mg (1.68 mmol). Reaction was carried out in refluxing tetrahydrofuran for 50 hours, and the crude product was eluted through a flash column (7:3 hexanes:ethyl acetate), 200 mg (65%), mp 214-215° C.; 1 H NMR (CDCl 3 ): δ 8.33 (s, 1H), 7.69 (d, 2H, J=8.3 Hz), 7.65 (s, 1H), 7.15 (d, 2H, J=8.3 Hz), 4.17 (s, 3H), 4.03 (s, 3H), 2.58 (s, 3H), 2.32 (s, 3H); MS (APCI): m/z 383 (M+H).
[0314] Anal. Calcd. for C 19 H 18 N 4 O 5 : C, 59.68; H, 4.74; N, 14.65. Found: C, 59.97; H, 4.68; N, 14.71.
[0315] [(6-Methyl-7-Nitro-2,3-dioxo-1,2,3,4-tetrahydro-quinoxaline-5-carbonyl)-amino]-acetic Acid (15)
[0316] To a stirred mixture of [(2,3-Dimethoxy-6-methyl-7-nitro-quinoxaline-5-carbonyl)-amino] acetic acid tert-butyl ester (14a) 150 mg (0.37 mmol) and sodium iodide 555 mg (3.7 mmol) in 25 mL acetonitrile is added dropwise chlorotrimethylsilane 0.46 mL (3.7 mmol). After addition was complete, the reaction mixture was refluxed under an atmosphere of nitrogen for 72 hours. The reaction mixture was quenched by pouring into 100 mL water, and the aqueous mixture was concentrated to 10 mL. The residue was mixed with ethyl acetate, and after stirring for 30 minutes, the product precipitated, 35 mg (29%), mp 250° C. (dec.); 1 H NMR (DMSO-d 6 ): δ 12.55 (br s, 1H), 8.40 (t, 1H, J=6.3 Hz), 7.84 (s, 1H), 4.07 (d, 2H, J=6.3 Hz), 2.43 (s, 3H); MS (APCI): m/z 323 (M +H). Anal. Calcd. for C 12 H 10 N 4 O 7 : C, 44.73; H, 3.13; N, 17.39. Found: C, 41.38; H, 3.12;N, 15.79.
Example 2
[0317] Scheme II procedure follows as indicated below.
[0318] 6-Methyl-1-7-nitro-quinoxaline-2,3-dione-5-hydrazide (4)
[0319] From Quinoxaline-2,3-dione-5-methyl Ester (A) (Compound 8 of Scheme I)
[0320] A solution of A (1.00 g, 3.6 mmol) in anhydrous hydrazine (10 mL) was stirred at room temperature under nitrogen for 24 hours. The solvent was removed under reduced pressure, and the residue was taken up in boiling water and filtered hot. Upon cooling the hydrazide precipitated as a yellow, crystalline solid (806 mg, 80%). MS (Cl) m/z =280 (M+1).
[0321] 5-(5-Amino-[1,3,4]oxadiazol-2-yl)-6-methyl-7-nitro-1,4-dihydro-quinoxaline-2,3-dione (6)
[0322] A mixture of compound 4 (300 mg, 1.08 mmol) and KHCO 3 (124 mg, 1.24 mmol) in water (20 mL) was heated to 70° C., at which point all solid went into solution. A solution of cyanogen bromide (126 mg, 1.19 mmol) in water (3 mL) was added dropwise. Approximately 30 seconds after addition was complete, the product began to precipitate. The reaction mixture was kept at 70° C. for 1 hour and upon cooling, compound 6 was collected and washed with both water and acetone (84 mg, 26%).
[0323] MS (Cl) m/z=305 (M+1).
[0324] 6-Methyl-7-nitro-5-(5-oxo-4,5-dihydro-[1,3,4]oxadiazol-2-yl)-1 4-dihydro-quinoxaline-2,3-dione (5)
[0325] A suspension of compound 4 (150 mg, 0.54 mmol) in anhydrous THF (10 mL) under nitrogen was treated dropwise with a 20% phosgene solution in toluene (10 mL). After stirring for 23 hours at room temperature, the precipitate was collected and washed with methanol to give an off-white solid (82 mg, 50%). MS (Cl) m/z=306 (M+1).
[0326] The compounds of the invention exhibit valuable biological properties because of their strong excitatory amino acid (EAA) antagonizing properties at one of several binding sites on glutamate receptors: the AMPA ((RS)-amino-3-hydroxy-5-methyl4-isoxazole)-propionic acid (or kainic acid) binding site on AMPA (non-NMDA) receptors or the glycine site of NMDA receptors.
[0327] The compounds of the present invention exhibit binding affinity for the AMPA receptors measured as described in Honore T., et al., Neuroscience Letters, 1985;54:27-32. Preferred compounds demonstrate IC 50 values: <100 μM in this assay. The compounds of the present invention exhibit binding affinity for the kainate site (non-NMDA receptor) measured as described in London E. D. and Coyle J., Mol. Pharmacol., 1979;15:492. The compounds of the present invention exhibit binding affinity for the glycine site of the NMDA receptor measured as described in Jones S. M., et al., Pharmacol. Methods, 1989;21:161. To measure functional AMPA antagonist activity, the effects of the agent on AMPA-induced neuronal damage in primary cortical neuronal cultures was examined using techniques similar to those outlined by Koh J -Y., et al., J. Neurosci., 1990; 10:693. In addition, the neuronal damage produced by long-term exposure to 100 μM AMPA may be measured by the release of the cytosolic enzyme lactate dehydrogenase (LDH).
[0328] Selected compounds of the present invention were tested by one or more of the above-described assays. The data obtained in the assays is set forth in Table 1 below. The IC 50 values set forth in Table 1 is a measure of the concentration ( 1 UM) of the test substance which inhibits 50% of an induced release from the tested receptors.
Table Of Biological Activity
[0329] 1. 5-(5-Amino-[1,3,4]oxadiazo-1-2yl)-6-methyl-7-nitro-1,4-dihydro-quinoxaline-2,3-dione
[0330] 2. 6-Methyl-7-nitro-5-(-oxo-4,5-dihydro-[1,3,4]oxadiazo-1-2-yl-1,4-dihydro-quinoxaline-2,3-dione
Example IC 50 AMPA IC 50 GLY 1 0.4 0.06 2 0.5 —
[0331] While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all of the possible equivalent forms or ramifications of the invention. It is understood that the terms used herein are merely descriptive rather than limiting, and that various changes may be made without departing from the spirit or scope of the invention.
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Described are neuroprotective agents of Formula I
wherein
R is an amino acid, a derivative thereof, or nitrogen heterocyclic ring which is saturated or unsaturated of from 5 to 8 members which may have additional oxygen or sulfur atoms therein and which may be substituted by one or more substituents selected from:
alkyl of from 1 to 4 carbon atoms,
hydroxyl,
alkoxy of from 1 to 4 carbon atoms,
—CF 3 ,
—CN,
-amino,
—C(O)R 11 ,or
—(CH 2 ) n -aryl of from 6 to 12 carbon atoms;
R must be attached through a carbon to the quinoxalinyl ring;
R 1 is H, alkyl of from 1 to 4 carbon atoms, phosphonoalkyl of from 1 to 4 carbon atoms, phosphoroalkyl of from 1 to 4 carbon atoms, carboxyalkyl of from 1 to 4 carbon atoms, —(CH 2 ) m C(O)R 11 , or hydroxy;
R 2 is hydrogen, hydroxy, or amine;
R 3 and R 4 are each independently H, alkyl of from 1 to 4 carbon atoms, cycloalkyl of from 5 to 7 carbon atoms, alkenyl of from 2 to 6 carbon atoms, halogen, haloalkyl of from 1 to 6 carbon atoms, nitro, cyano, SO 2 CF 3 , CH 2 SO 2 R 7 , (CH 2 ) m CO 2 R 7 , (CH 2 ) m CONR 7 R 8 , (CH 2 ) m SO 2 NR 8 R 9 , or NHCOR 7 ;
R 5 is H, alkyl of from 1 to 4 carbon atoms, alkenyl of from 2 to 6 carbon atoms, cycloalkyl of from 5 to 7 carbon atoms, halogen, haloalkyl of from 1 to 4 carbon atoms, —(CH 2 ) m aryl of from 6 to 10 carbon atoms, nitro, cyano, SO 2 CF 3 , (CH 2 ) m CO 2 R 9 , (CH 2 ) m CONR 9 R 10 , SO 2 NR 9 R 10 , SO 2 R 7 , (CH 2 ) m SO 2 R 7 , NHCOR 9 , —(CH 2 ) m heterocyclic of from 6 to 10 atoms which may contain nitrogen, oxygen, sulfur, and/or —(CH 2 ) n R;
R 5 may be joined at R 4 to form a cyclic aromatic or a heterocyclic ring of from 5 to 7 members which may contain nitrogen, oxygen, or sulfur;
R 7 , R 8 , R 9 , and R 10 are each independently selected from hydrogen, alkyl of from 1 to 4 carbon atoms, cycloalkyl of from 5 to 7 carbon atoms, haloalkyl of from 1 to 4 carbon atoms, or —(CH 2 ) m R 11 ;
R 11 is alkyl or alkoxy of from 1 to 4 carbon atoms, hydroxy, or amino;
m is an integer of from 0 to 4;
n is an integer of from 0 to 4;
(m may or may not be equal to n);
or a pharmaceutically acceptable salt thereof.
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TECHNICAL FIELD
The instant invention pertains to metal halide lamps, and, more particularly to metal halide lamps enclosed in a reflective optic. Such applications include, but are not limited to spot and flood illumination, highlighting objects de art, merchandise and facade illumination, and other general illumination applications.
BACKGROUND OF THE INVENTION
Low wattage quartz metal halide and miniature ceramic metal halide (HCl) lamps have been on the market for some time. These lamps are designed to be small concentrated sources of light for inclusion into reflectors for down-lighting and concentrated illumination (spots or floods). A key advantage offered by these lamps is the potential replacement of tungsten-halogen PAR or AR reflector lamps with more energy efficient metal halide lamps while preserving good color rendition, and uniform beam color. Examples of these types of lamps are described in U.S. Patent Publication Nos. 2003/0193280 and 2005/0184632.
However, metal halide lamps in reflector applications tend to exhibit strong color variations in the far field beam which are undesirable and essentially absent in tungsten-halogen PAR lamps. These color variations occur because of segregation in the electric arc of the radiating species, absorption of the salts on the burner interior surface and radiation escaping from the burner which does not impinge on the primary optical control surface. This color separation is somewhat mitigated by the use of dappled glass lenses over the output aperture of the reflector and swirl lines on the interior of the reflector. Still, it would be an advantage to improve the homogenization of the color of the emitted light across the beam pattern of the lamp.
SUMMARY OF THE INVENTION
It is an object of the invention to obviate the disadvantages of the prior art
It is another object of the invention to provide better color uniformity in the projected beam of a metal halide reflector lamp.
In accordance with an object of the invention, there is provided a novel metal halide reflector lamp having a passive optical element to scramble, color mix, and otherwise commingle the light emitted by the metal halide burner. The optical element is placed close to the radiating plasma volume to intercept a large solid angle. Preferably, the optical element substantially intercepts the emitted light within a solid angle that has its vertex at the center of the discharge volume of the burner and is subtended by the open end of the reflector. The optical element can be designed to scatter, reflect or refract the light emanating in this solid angle which otherwise would not impinge on the primary optical control surface of the reflector. Without the optical element, the light emitted within the solid angle does not interact with the reflector facets or swirls and cannot be color mixed with the light from other solid angles.
The optical element of the instant invention can be made of quartz, molded and sintered polycrystalline alumina (PCA), sapphire for transparent objects, or any of the other translucent/transparent ceramics such as aluminum nitride, aluminum oxynitride, or yttrium aluminum garnet. The only requirement is that it not chemically react with the lamp components, or crack at operation temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of the measured distribution of illuminance on a target screen placed at 1.6 m from a 70 W HCl burner in a PAR 38 reflector lamp.
FIG. 2 is a plot of the measured spatial color temperature distribution of the light emitted from a horizontally burning 70 W HCl burner in a PAR 38 reflector lamp.
FIGS. 3 a and 3 b are illustrations of a prior art ceramic metal halide reflector lamp ( FIG. 3 a ) and an enlarged view of its jacketed ceramic burner ( FIG. 3 b ).
FIG. 4 shows a ratio of spectral radiance of light passing through a salt droplet to light passing through the wall of a polycrystalline alumina burner.
FIGS. 5 a and 5 b are illustrations showing the placement of the optical element in a ceramic metal halide lamp.
FIGS. 6 a and 6 b are front and cross-sectional views, respectively, of a first embodiment of the optical element.
FIGS. 7 a and 7 b are front and cross-sectional views, respectively, of a second embodiment of the optical element.
FIGS. 8 a and 8 b are front and cross-sectional views, respectively, of a third embodiment of the optical element.
DETAILED DESCRIPTION OF THE INVENTION
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims taken in conjunction with the above-described drawings.
FIG. 1 shows the isolux lines measured for a 70 W HCl PAR38 lamp burning horizontally and projected onto a screen 1.6 m away. As shown, the luminous intensity should decrease uniformly outward from the center (>17500 lx (lumens/m 2 )) of the beam pattern. However, existing metal halide reflector lamps exhibit a color non-uniformity over this field, particularly when operated in other than a vertical, base-up orientation. The non-uniformity in the correlated color temperature (CCT) for a horizontally operated 70 W HCl PAR38 lamp is shown in FIG. 2 . The CCT metric displayed in FIG. 2 is a common metric used to describe the color of the light emitted by a lamp. Another less commonly used metric is to map the CIE chromaticity coordinates (x,y) using the 1931 or 1976 systems.
The non-uniformity of the metal halide reflector lamps has its roots in the color separation mechanisms described above and may be understood by reference to FIGS. 3 a and 3 b . In particular, FIG. 3 a illustrates how the irregular and uncontrollable positioning of the salt melt pool 5 can affect the light emanating from the discharge volume 2 of burner 7 especially in the isolated solid angle, dΩ=2π(1−cos θ), as defined by polar angle, θ. Unlike the light emitted in directions 13 , 15 , light emitted from the burner 7 in the solid angle (shown delimited by dashed arrows 10 , 11 ) does not impinge on the primary optical control surface, viz. the reflector 20 . Any color variation within this uncontrolled solid angle cannot be easily mixed with the light from the rest of the burner prior to exiting the open end 17 of reflector 20 . In fact, when the arc radiation passes through the salt pool (as shown by arrow 3 in FIG. 3 b ), the radiation is strongly filtered, as the salts absorb preferentially in the near UV and blue. Consequently light from the isolated solid angle dΩ can be reddish yellow. This is illustrated in FIG. 4 which shows the absorption of the salt pool for a typical 3000K rare earth salt blend. In particular, FIG. 4 shows a ratio of spectral radiance of light passing through a salt droplet to light passing through the wall of a polycrystalline alumina burner (as indicated by arrow 4 in FIG. 3 b ). This preferential wavelength absorption may have the effect of making objects in the periphery appear reddish on one side and bluish on the other.
With reference to FIG. 5 a , an embodiment of a ceramic burner 7 of a preferred reflector lamp according to this invention is shown mounted in its outer jacket 9 . The ceramic burner 7 has two capillaries 35 , 37 which extend outwardly from discharge volume 2 . The ceramic burner 7 is sealed within tubular outer jacket 9 by means of press seal 33 and molybdenum foils 32 which act as electrical feedthroughs. The ceramic burner 7 (also referred to as an arc tube or discharge vessel) is made of a polycrystalline alumina (PCA) ceramic, although other translucent/transparent ceramics like sapphire, aluminum nitride, aluminum oxynitride and yttrium aluminum garnet may be used. In an alternate embodiment, the burner may be made of quartz in which case the ends will have press seals similar to the press seal used to seal the outer jacket. The press seals would replace the capillaries of the ceramic burner. In another alternate embodiment, the capillaries of the ceramic burner 7 are located of the same side of the discharge volume (a so-called single-ended arc tube).
The proximal capillary 35 (closest to the press seal 33 ) which extends outwardly from the proximal side 48 of the discharge volume 2 is electrically connected to lead 43 . The distal capillary 37 (farthest from the press seal 33 ) which extends outwardly from the distal side 49 of the discharge volume 2 is electrically connected to lead 45 by means of return wire 31 . A getter flag 41 is attached to return wire 31 to reduce contamination in the outer jacket 9 . The discharge volume 2 contains an enclosed chemistry to produce useful light. Such chemistry can be, but is not limited to, a blend of rare earth salts such as halides of Dy, Tm, Ho, with halides of an alkali such as Na and an alkaline earth such as Ca. Iodides are the preferred halides. Other chemistries may be Ce or Pr halides. The salt fill may also contain metallic Hg. The discharge volume also contains an inert buffer gas to permit lamp starting. The gas may be Ar, Kr, Ne or Xe or mixtures thereof, and may be in the cold fill pressure range of 0.004 bar to 15 bar depending on whether the lamp is intended for slow warm-up or more rapid warm-up as an automotive D lamp (typically ˜10 bar Xe). Other fill chemistries may be employed and the instant invention is not dependent on the particular fill.
Referring again to FIG. 5 a , optical element 30 is mounted on distal capillary 37 and close to the discharge volume 2 of ceramic burner 7 . In this embodiment, the optical element 30 is a shaped ceramic disk having a central hole that allows the distal capillary 37 to pass through. The optical element 30 is in contact with, but not necessarily attached to, the distal capillary 37 . The burner 7 and its outer jacket 9 is mounted in a reflector 20 with the press seal 33 adjacent to reflector base 25 (as illustrated for the prior art lamp shown in FIG. 3 a ). The reflector 20 may be an optic of revolution symmetry around the optic axis. It may also be molded in a non-symmetric shape such as is required for maximum energy transport consistent with principles of non-imaging optics and the laws of thermodynamics.
With reference to FIG. 5 b , optical element 30 is shaped to reflect or scatter radiation whose angular distribution from the end of the active discharge volume will not impinge on the primary optical control surface of the reflector 20 . This region is defined by a solid cone having its vertex at the center of the discharge volume 2 and its base (or directrix) as the open end of reflector 20 . The 3-dimensional lateral surface of the cone and the included solid angle dΩ are shown in a 2-dimensional projection delimited by arrows 10 , 11 , where dΩ=2π(1−cos θ). The light emitted within solid angle dΩ interacts with the optical element 30 and may be partially reflected towards the reflector 20 (as shown by arrows 50 , 51 ), refracted or scattered in order to better homogenize the light leaving the reflector lamp. The position of the optical element may be maintained by welding the getter flag to the return wire so that the optical element is confined from movement away from the active discharge volume. A separate cross wire may also be welded to the return wire to confine the optical element.
FIGS. 6 a (front view) and 6 b (cross-sectional view) illustrate a first embodiment of the optical element. In this case, the optical element 61 is a translucent polycrystalline alumina (PCA) plano-convex shape with a central hole 65 to accommodate the distal capillary. The diameter of the central hole, d, is large enough to pass the capillary, and the outer diameter, D, is small enough to fit inside the outer jacket (typically made of quartz). The hole 65 in the optical element can be a right circular cylinder such as a diamond drill would produce or something more complicated such as a hole with flutes. In the latter configuration, the flutes would be in contact with the capillary to minimize the contact surface area and reduce heat transfer into the optical element and cooling of the capillary. A groove 67 (or an additional off-center hole) is used to accommodate the return wire attached to the distal capillary. The optical element 61 is mounted with its convex surface 60 facing the light emitted from the discharge volume of the burner. This element is designed to scatter the radiation in the isolated solid angle back onto the primary reflector for commingling.
FIGS. 7 a (front view) and 7 b (cross-sectional view) illustrate another embodiment of the optical element. Here, the optical element 70 is a faceted, plano-convex shape with a central hole 65 to accommodate the distal capillary. The optical element 70 is mounted with its faceted surface 72 facing the light emitted from the discharge volume of the burner. This element is designed to reflect the radiation in the isolated solid angle back onto the primary reflector for commingling. A metallic or dichroic reflective coating may be applied to the faceted surface 72 .
FIGS. 8 a (front view) and 8 b (cross-sectional view) illustrate a further embodiment of the optical element. In this embodiment, the optical element 80 is transparent with a faceted surface 85 for refracting the light in the isolated solid angle. The light ray 81 from the burner impinges on the faceted surface 85 . A portion of the light 86 is reflected and the greater part 87 is refracted directly into the beam pattern of the primary optical control surface. The rear surface 82 of the optical element 80 is roughened to further scatter the refracted light in transit to the target surface.
While there have been shown and described what are at present considered to be preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims.
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A novel metal halide reflector lamp is described wherein the reflector lamp has a passive optical element to scramble, color mix, and otherwise commingle the light emitted by the metal halide burner. The optical element is placed close to the radiating plasma volume to intercept a large solid angle. Preferably, the optical element substantially intercepts the emitted light within a solid angle that has its vertex at the center of the discharge volume of the burner and is subtended by the open end of the reflector. The optical element can be designed to scatter, reflect or refract the light emanating in this solid angle which otherwise would not impinge on the primary optical control surface of the reflector.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates generally to structural sandwich panels, and more specifically to multi-layered, oriented unidirectional fiber panels wherein the relative thickness of upper and lower laminae are manipulated to improve the load carrying properties of such panels without incurring a weight penalty.
2. Background
Various types of sandwich panels are disclosed in U.S. Pat. Nos. 3,963,846; 4,251,579; 4,292,356; 4,416,349; 4,990,391; and 5,106,668. Some panels have solid cores, while others are cavitated. A level, or smooth, surface covering is usually placed over the core material. Most commercial paneling is flat, although beneficial curved panels are known. (See U.S. Pat. Nos. 5,064,493 and 5,126,183).
Though there are many uses for structural sandwich panels, they have been found to be particularly useful in aircraft, as typically they are light but strong. U.S. Pat. Nos. 4,292,356; 4,416,349; and 4,990,391 disclose sandwich panels for aircraft noise attenuation purposes. This type of panel is meant to reduce interior noise by damping the vibrations of a reinforced skin structure. This is thought also to improve the sonic fatigue life of the vibrating structure and attached equipment.
U.S. Pat. No. 4,25 1,579 concerns the use of honeycomb sandwich panels in aircraft and other vehicles to fight fire. A fire-extinguishing fluid is disposed within the honeycomb cells and is held therein by facing sheets. The panel is arranged so that it is more rigidly enclosed on one side than the other. On impact, or entry of a projectile, the facing sheet on the less rigidly enclosed side of the panel preferentially breaks up or peels away so that the fire-extinguishing fluid is discharged in the preferred direction.
Honeycomb sandwich panels have long been used in aircraft flooring. Yet there remains a significant trade-off between strength and weight that is critical to aircraft design and operation. Aircraft flooring must have compressive properties sufficient to withstand the weight of loaded fixtures (such as seats), the walking of passengers and crew and the like, while at the same time being light enough so as not to create an undue weight burden. The advantages of stronger and lighter flooring materials being known, the search has continued for better designs.
U.S. Pat. No. 5,106,668 embodies one attempt to create a stronger structural sandwich panel. It uses a multi-layer dual honeycomb structure. A high-density first honeycomb core is attached to a second, low-density honeycomb core. The two honeycomb cores share a common septum or interior structural skin.
It is believed that unbalanced panels, such as an aluminum skin bonded to a balsa core, have been used in some aircraft flooring applications. Unbalanced woven glass skin panels are known to be used in bulkheads, cabinetry and smaller aircraft flooring.
It is an object of the present invention to advance the art of structural sandwich panels for use in aircraft flooring (and other applications) by further increasing the compressive strength and structural integrity of sandwich panels without incurring a weight penalty.
SUMMARY OF THE INVENTION
According to the present invention, the foregoing and other objects and advantages are attained by manipulating the thickness of the top and bottom laminates of the panel to alter strength and stiffness such that the top laminate is made to withstand greater compressive forces while the bottom laminate is provided with enhanced tensility.
In accordance with the invention, there is provided a multi-layered, unbalanced, bonded sandwich panel having improved top load support capability per unit of weight. The panel has a core, to the upper surface of which is affixed a multiple-ply top laminate. Similarly affixed to the lower surface of the core is a multiple-ply bottom laminate. Several preferred thicknesses are provided for the top and bottom laminates and for the ply components of the laminates. The top laminate supplies increased compressive resistance, while the bottom layer has an enhanced ability to withstand tensile forces. The core is preferably a honeycomb core. Unidirectional, fiberglass epoxy prepreg lamina are favored for each ply, although the invention is not limited to the use of this fiber and resin system. Carbon fiber, aromatic polyamides, (aramids), such as are sold by Du Pont under the trademark "KEVLAR," or other fibers, as well as phenolic or polyamide resin systems, could be used.
Another aspect of the invention is the orientation of the multiple lamina upon the honeycomb core. It should be understood that a honeycomb core constructed in accordance with standard practice is known to have a "ribbon direction," defined by the direction in which the ribbons of material used to form the honeycomb core longitudinally extend. The top laminate provided herein preferably includes an inner ply having a fiber direction perpendicular to the core's ribbon direction and an outer ply having a fiber direction parallel to the ribbon direction. Likewise, the bottom laminate preferably includes an inner ply having a fiber direction perpendicular to the core's ribbon direction and an outer ply having a fiber direction parallel to the ribbon direction. Although the outer and inner plies of the laminates are always perpendicular to each other, the fiber direction of the inner plies can be oriented perpendicular or parallel to the core ribbon direction.
The panels of the present invention have been shown to have advantages over those of the prior art through standard testing procedures for characteristics such as stabilized core compression, impact strength, load deflection, panel shear, long beam flexure, insert shear, and drum peel value.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein there is shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated for carrying out the invention.
As will be realized, the invention is capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the description should be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of the preferred embodiment of the invention.
FIG. 2 is a enlarged sectional view of the preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, the preferred panel of the present invention is generally indicated by the reference numeral 10. Panel 10 includes a core 12. Core 12 has an upper surface or upper cell edge 14, a lower surface or lower cell edge 16, and a known ribbon direction (as described above). A honeycomb core is favored, although other suitable core configurations will suffice. The invention is not limited in any fashion to one or more particular core materials, and a variety of substances are acceptable, metallic and nonmetallic. Aluminum, aramid or aramid/phenolic sheet structures, such as are sold by Du Pont under the trademarks "NOMEX" and "KOREX", thermoplastics, glass and balsa are examples. The core should, however, have mechanical and physical properties making it readily adaptable to current manufacturing techniques.
Should a metallic core be desired, and such is preferred, the well known "5052" aluminum alloy honeycomb core is recommended. An 1/8 inch cell, 5052 aluminum alloy with a nominal density of 8.1 lbs./ft 3 is preferred.
Nonmetallic honeycomb cores, however, are preferred for certain applications. They generally consist of thin sheets of pressed nonmetallic material coated with resin, bonded with an adhesive, and expanded or formed into specific cell sizes. The core material is cured sufficient to withstand machining without excessive node bond (bonded area between cells) or cell wall failure. The preferred I nonmetallic honeycomb core is a phenolic coated aramid sheet structure having a mass density of about 5.0 lbs./ft 3 . An alternative core is similarly composed, but has a mass density of about 9.0 lbs./ft 3 .
The preferred core splice adhesive for use in manufacturing the panels of the present invention, if such is necessary, is a structural foaming adhesive, such as a low density expandable epoxy film.
Core 12 should be uniform in quality and condition, clean and free from foreign materials, excess resin accumulations, starved areas, dip-coat separations, tackiness, blisters, splices, and other defects detrimental to fabrication, appearance and performance.
A top laminate 18 is adhesively affixed, in a manner well known in the art, to upper cell edge 14 of core 12. Top laminate 18 is a multiple-ply laminate. Preferably, top laminate 18 comprises an inner ply 20, which is mated to upper cell edge 14 of core 12. An outer ply 22 is affixed above inner ply 20.
A bottom laminate 24 is similarly affixed to bottom cell edge 16 of core 12. Bottom laminate 24 is also a multiple-ply laminate. It preferably comprises an inner ply 26 mated to bottom cell edge 16 of core 12, and an outer ply 28. Top laminate 18 is thicker than bottom laminate 24 as described in detail below.
The materials used for top laminate 18 and bottom laminate 24 may vary, and include glass epoxy, graphite and around fibers. The preferred material is a unidirectional, fiberglass epoxy prepreg. It consists of collimated glass fibers which are coated or impregnated with a modified epoxy resin system. The weight, resin content and color of the epoxy prepreg may be varied depending upon design specifications. The resin used for coating of the reinforcing fiber should meet or exceed the mechanical requirements of MIL-R-9299, Type II, Class 1 materials.
Similar to the requirements for core 12, the laminate material should be uniform in quality and condition and be clean and free from foreign materials, excess resin accumulation, resin starved areas, and excessive tackiness. The laminate material should have no gaps between fibers greater than 0.05 inch and should have no splices or other defects detrimental to fabrication, appearance, and performance of the end item. It should also be capable of machining without fraying or delamination.
For the preferred embodiment, the panels are fabricated by first dehydrating the NM 0104-002 Type I or II honeycomb core for a minimum of one hour at 220°±15° F. in a hot air circulating oven. The NM 5015 Class I and II prepreg materials are warmed to room temperature as is the foaming adhesive. (The prepreg material and adhesive are stored at a temperature below 0° F.) The layup and holding of components prior to cure should take place in the 65° to 85° F. range.
The unidirectional, fiberglass epoxy prepreg plies 20, 22, 26, 28 are then adhesively affixed to core 12 in the following preferred orientation. Top inner ply 20 is affixed to upper surface 14 of core 12 so that its fiber direction runs perpendicular to the ribbon direction of core 12. Top outer ply 22 is then overlaid top inner ply 20 such that the fiber direction of top outer ply 22 runs parallel to the ribbon direction of core 12 (and perpendicular to that of top inner ply 20). In a corresponding fashion, bottom inner ply 26 is affixed to bottom surface 16 of core 12; the fiber direction running perpendicular to the ribbon direction (and parallel to that of top inner ply 20). Bottom outer ply 28 is overlaid bottom inner ply 26; the fiber direction running parallel to the ribbon direction (and parallel to that of top outer ply 22). Thus, top inner ply 20 and bottom inner ply 26 both have a fiber direction that is perpendicular to the ribbon direction of core 12. Likewise, top outer ply 22 and bottom outer ply 28 have a fiber direction that is parallel to the ribbon direction.
Though the preceding orientation is preferred, an alternate embodiment wherein the fiber direction of inner plies 20, 26 runs parallel to the ribbon direction of core 12 while the fiber direction of outer plies 22, 28 is perpendicular to the ribbon direction remains within the scope of the present invention.
The panels of this invention may be manufactured in a variety of sizes. For purposes of illustration, however, the following discussion concerning ply thicknesses depends from a standard panel of a thickness between about 0.39 in. (0.99 cm) and 0.41 in. (1.04 cm). This is the most common size of panel used in aircraft flooring applications.
As mentioned previously, top laminate 18 is thicker than bottom laminate 24. In the most preferred embodiment, top laminate 18 is about 1.3 (and more specifically about 1.3333) times the thickness of bottom laminate 24. This value was derived through trial and error testing to balance load bearing capability against panel stiffness and bending characteristics. The ratio of 1.3333 to 1 produces optimum results. Where the panel is of a standard thickness of 0.4 inches, top laminate 18 has a preferred thickness of about 0.01428 in. (0.36271 mm), and bottom laminate 24 has a thickness of about 0.01072 in. (0.27229 mm). Being further defined, each ply 20, 22 of top laminate 18 has a thickness of about 0.00714 in. (0.18136 mm) and each ply 26, 28 of bottom laminate 24 has a thickness of about 0.00536 in. (0.13615 mm).
The preferred areal weight of a 0.4 inch thick panel is about 0.560 lbs./ft 2 (2734 g/m 2 ). In such a preferred panel, top laminate 18 has an areal weight of about 0.0934 lbs./ft 2 (456 g/m 2 ), and bottom laminate 24 has an areal weight of about 0.07374 lbs./ft 2 (360 g/m2). It should be understood that the above areal weights are for the fibers only and do not include the resin. The total areal weight of top laminate 18 is 776 g/m 2 , while the total areal weight of bottom laminate 24 is 637 g/m 2 . Each ply 20, 22 of top laminate 18 has an areal weight (based on fiber) of about 0.0467 lbs./ft 2 (228 g/m 2 ), and each ply 26, 28 of bottom laminate 24 has an areal weight (fiber) of about 0.03687 lbs./ft 2 (180 g/m 2 ). The total areal weights (fiber and resin) of plies 20, 22, 26 and 28 are as follows: (The tighter tolerances are maintained, the better the result.)
______________________________________ PLY WT.______________________________________ 20 480 g/m.sup.2 22 296 g/m.sup.2 26 404 g/m.sup.2 28 232 g/m.sup.2______________________________________
A numerical formula has been derived as follows to describe the unique relationship of ply and core thickness to strength and deflection of the panels of the present invention. In this derivation, it is presumed that the thickness of top laminate 18 ( t top.sheet) equals 1.3333 times the thickness of bottom laminate 24 ( t bottom.sheet). The unique relationship described allows for easy adaptation of design parameters to account for specific target values. A change in stiffness is characterized by the formula:
0.0092(1+ % Δstiff)=0.91(t.sub.B)-0.534(t.sub.B.sup.2)+0.778(t.sub.B.sup.3)
where,
% Δstrength=% change in strength desired,
% Δstiff=% change in stiffness desired, and
t B =thickness of bottom sheet.
Strength change is also quantifiable as follows:
[246.56/(1% Δstrength)]=-75[(1.11*10.sup.18 t.sub.B -1.52*10.sup.18)/(4.57*10.sup.18 t.sub.B -2.67*10.sup.20 t.sub.B.sup.2 +3.89*10.sup.20 t.sub.B.sup.3)]
It should be noted that for a given percentage increase desired, the increase for stiffness will be larger than the increase required for strength. But only by a small amount.
The bottom laminate thickness required for a given change in stiffness is derived. It is presumed that the thickness of the panel is 0.4 inches.
(a) t T =1.34t B
Assuming a unit width panel for ease of derivation:
(b)C.sub.p =[t.sub.T (t.sub.p -0.5t.sub.T)+(0.5t.sub.B.sup.2)]/(t.sub.T +t.sub.B)
(c)I.sub.p =t.sub.T (t.sub.p -0.5t.sub.T -C.sub.p).sup.2 +t.sub.B (0.5t.sub.B -C.sub.p).sup.2
All ratios are based on the preferred thickness for the top laminate:
(d) I o =I p
where,
C p =Centroid of Panel,
I p =moment of inertia of panel,
I o =moment of inertia of original 737 floor,
t T =thickness of top sheet,
t B =thickness of bottom sheet, and
t p =thickness of panel.
As an example, where
t B =0.0107 in
t p =0.40 in Substitute (a) and (c) into (d):
I.sub.o =1.34t.sub.B (t.sub.p -0.67t.sub.B -1.34t.sub.B (t.sub.B -0.67t.sub.B)+0.214t.sub.B).sup.2+ t.sub.B (0.5t.sub.B -1.34t.sub.B (t.sub.p -0.67t.sub.B)+0.214t.sub.B).sup.2
which expands to: ##EQU1##
Expand equation (e) and substitute in the original moment of inertia for the 737 floor. The following equation can be used to determine the bottom panel thickness required for a desired increase in bending stiffness.
9.2*10.sup.-4 (1+% Δstiff)=0.57t.sub.B t.sub.p.sup.2 -1.34t.sub.B.sup.2 t.sub.p +0.78t.sub.B.sup.3
The bottom laminate thickness required for a given change in strength is derived as follows:
Solve the following equation:
(f)MC.sub.o /I.sub.o =(MC.sub.new I/.sub.new)(1+% Δstrength)
. . substitute (b) into (f):
(g)(1.34t.sub.B (t.sub.p -0.67t.sub.B)+0.5t.sub.B.sup.2)/(2.34t.sub.B *I.sub.o)=(C.sub.new /I.sub.new)(1+% Δstrength)
Solve for the constant that represents the left side of the equation:
(1.34t.sub.B (t.sub.p -0.67t.sub.B)+0.5t.sub.B.sup.2)/(2.34t.sub.B *I.sub.o)=246.56 in.sup.2
Insert the above constant into (g):
(h)246.56=(.sup.c new/.sup.I new)(1+% Δstrength)
Insert (b) and (e) into (h):
246.56=[(1.34t.sub.B (t.sub.p -0.67t.sub.B)+0.5t.sub.B.sup.2)/(2.34t.sub.B (0.57t.sub.B t.sub.p.sup.2 -1.34t.sub.B.sup.2 t.sub.p +0.78t.sub.B.sup.3))](1+% Δstrength)
Simplifying the above equation yields the following equation, which can be used to determine the bottom panel thickness required for a desired increase in strength.
246.56/(1+% Δstrength)=-75[(1.11*10.sup.18 t.sub.B -1.52*10.sup.18)/4.57*10.sup.18 t.sub.B -2.67*10.sup.20 t.sub.B.sup.2 +3.89*10.sup.20 t.sub.B.sup.3)
While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the method hereinabove described without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.
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A multi-layered, unbalanced, bonded sandwich panel having improved top load support capability per unit of weight is disclosed. The panel has a core, to the upper surface of which is affixed a multiple-ply top laminate. Similarly affixed to the lower surface of the core is a multiple-ply bottom laminate. The top laminate is thicker than the bottom laminate and supplies increased compressive resistance, while the bottom layer has an enhanced ability to withstand tensile forces. The core is preferably a honeycomb core, and unidirectional, fiberglass epoxy prepreg lamina are favored for each ply.
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BACKGROUND OF THE INVENTION
The present invention relates to signal reproducing methods and signal reproducing apparatuses, and more particularly to a method and apparatus for reproducing a signal which is recorded with a high recording density.
Due to the rapid information transfer capabilities and large storage capacity of recent magnetic recording and reproducing devices, there is a demand to improve the recording density of magnetic recording and reproducing apparatuses. Various systems using waveform interference have been proposed to improve the recording density.
In prior art magnetic recording and reproducing apparatus, a waveform interference technique called Partial Response Maximum Likelihood (PRML) technique is employed to improve recording density. The PRML technique is a signal processing technique for realizing a high-density recording on magnetic disk and optical disk, and combines the Partial Response (PR) technique and the Maximum Likelihood (ML) technique.
FIG. 8 is a diagram showing the general construction of a magnetic disk unit 61. The magnetic disk unit 61 includes a magnetic disk 62 that is rotated by a spindle motor 63, and a magnetic head 64 which faces the magnetic disk 62. A recording signal is recorded on the magnetic disk 62 by generating a magnetic field dependent on the recording signal of the magnetic head 64. The recording signal recorded on the magnetic disk 62 is later reproduced by the magnetic head 64, which detects changes in the recorded magnetic poles.
The magnetic head 64 is connected to a voice coil motor (which is not shown) via an arm 65, and is moved in a radial direction on the magnetic disk 62, as indicated by arrow A. Signals are recorded on tracks of the magnetic disk 62, and the tracks are formed about a rotation center of the magnetic disk 62.
The magnetic head 64 is coupled to a recording system 66, which processes the recording signal, and a reproducing system 67, which reproduces a head reproduced signal that is reproduced by the magnetic head 64. The recording system 66 includes an encoder 68 which encodes the recording signal received from an input terminal T IN , and a recording equalizer 69, which equalizes the encoded recording signal from the encoder 68 so that a high-density recording is possible. The output signal of the recording equalizer 69 is supplied to the magnetic head 64.
The reproducing system 67 includes a reproducing equalizer 70, an ML detector 71, and decoder 72. The equalizer 70 receives the high-density head reproduced signal from the magnetic head 64, which converts the magnetic information into electrical information. The equalizer 70 equalizes the head reproduced signal using waveform interference. The ML detector 71 reproduces an output signal from the equalizer 70 into the original signal using waveform interference. The decoder 72 reproduces the recording signal from the output signal of the ML detector 71, and outputs the recording signal through an output terminal T OUT .
The magnetic disk unit 61 performs signal processing using waveform interference for high-density recording through the use of the recording equalizer 69, the reproducing equalizer 70, the ML detector 71 and the other components discussed. Techniques that have been proposed for carrying out such signal processing are the PR technique and a Fixed Delay Tree Search with Decision Feedback (FDTS/DF) technique.
When attempts are made to further improve the high-density recording by using the PR technique, the FDTS technique and the like, it becomes essential to reduce the equalization loss and the correlation noise in the reproducing equalizer 70, the ML detector 71 and the other components found in the reproducing system 67.
FIG. 9 is a block diagram showing the construction of a reproducing system employing the PRML technique. As shown in FIG. 9, the head reproduced signal is received through an input terminal IN and is supplied to a feedforward filter 81, which corresponds to the reproducing equalizer 70 shown in FIG. 8. The feedforward filter 81 carries out a wave-shaping process with respect to the head reproduced signal so that the level of the head reproduced signal will not affect the preceding signal. The feedforward filter 81 also equalizes the target waveform by controlling the waveform interference constant to the subsequent signal. The signal which is equalized to the target waveform by the feedforward filter 81 is supplied to an ML detector 82, which corresponds to the ML detector 71 shown in FIG. 8. The ML detector 82 detects the most likely sequence of the signal from the feedforward filter 81 having the target waveform and makes a correlation from the waveform interference. An output signal of this ML detector 82 is output through an output terminal OUT.
In the reproducing system employing the PRML technique, the equalization loss in the feedforward filter increases as the line density increases. In order to reduce this equalization loss, an impulse response such as PR4, EPR4 or EEPR4 is used in the feedforward filter 81.
FIG. 10 shows impulse response characteristics of the various impulse responses. FIG. 10 (A) shows the impulse response characteristic of the PR4, and FIG. 10 (B) shows the impulse response of the EPR4, and FIG. 10(C) shows the impulse response of the EEPR4.
The PR4 is sometimes also referred to as PR (1, 0, -1), and has the impulse response shown in FIG. 10 (A). This impulse response is realized by giving to the reproduced signal a characteristic (1-D) (1+D), where D denotes a 1-bit delay.
The EPR4 is sometimes also referred to as PR (1, 1, -1, -1), and has the impulse response shown in FIG. 10 (B). This impulse response is realized by giving to the reproduced signal a characteristic (1-D) (1+D) 2 , where D denotes a 1-bit delay.
The EEPR4 is sometimes also referred to as PR (1, 2, -2, -1), and has the impulse response shown in FIG. 10 (C). This impulse response is realized by giving to the reproduced signal a characteristic (1-D) (1+D) 3 , where D denotes a 1-bit delay.
However, even when the impulse responses such as the PR4, EPR4 or EEPR4 are used, while it is possible to reduce the increase of the equalization loss, the equalization loss caused by the increase of the line density still cannot be prevented.
FIG. 11 shows the equalization loss with respect to a normalized line density of the recording signal for the PR4, EPR4 and EEPR4. In FIG. 11, the equalization loss of the PR4 is indicated by a solid line, the equalization loss of the EPR4 is indicated by a dotted line, and the equalization loss of the EEPR4 is indicated by a one-dot chain line.
As shown in FIG. 11, the equalization loss of the EPR4 is smaller than that of the PR4, and the equalization loss the EEPR4 is smaller than that of the EPR4. However, the equalization loss increases as the line density increases, for each of the PR4, EPR4 and EEPR4.
FIG. 12 shows equalization gains with respect to the normalized frequency for the PR4, EPR4 and EEPR4. In FIG. 12, the equalization gain of the PR4 is indicated by a solid line, the equalization gain of the EPR4 is indicated by a dotted line, and the equalization gain of the EEPR4 is indicated by a one-dot chain line.
As shown in FIG. 12, the noise increases because the equalization gain greatly changes depending on the normalized frequency. For this reason, the correlation noise at the ML detector 82 cannot be neglected.
FIG. 13 shows signal-to-noise (S/N) ratios with respect to the normalized line density for the PR4, EPR4 and EEPR4. In FIG. 13, the S/N ratio of the PR4 is indicated by a solid line, the S/N ratio of the EPR4 is indicated by a dotted line, and the S/N ratio of the EEPR4 is indicated by a one-dot chain line. As shown in FIG. 13, the S/N ratio becomes smaller as the line density increases, and the effects of the S/N ratio are more notable as the line density increases.
The convolution steps increase in the EPR4 as compared to the PR4, and the convolution steps increase in the EEPR4 as compared to the EPR4. As the convolution steps increase, it is possible to reduce the noise at the ML detector 82.
FIG. 14 shows S/N ratios at a portion of the ML detector 82 with respect to the normalized line density for the PR4, EPR4 and EEPR4. In FIG. 14, the S/N ratio of the PR4 is indicated by a solid line, the S/N ratio of the EPR4 is indicated by a dotted line, and the S/N ratio of the EEPR4 is indicated by a one-dot chain line. As shown in FIG. 14, the S/N ratio of the ML detector 82 is larger for the EPR4 and the EEPR4 than for the PR4.
FIG. 15 shows peak signal/root mean square (RMS) noise with respect to the normalized line density for the PR4, EPR4 and EEPR4. In FIG. 15, the peak signal/RMS noise of the PR4 is indicated by a solid line, the peak signal/RMS noise of the EPR4 is indicated by a dotted line, and the peak signal/RMS noise of the EEPR4 is indicated by a one-dot chain line.
As shown in FIG. 15, the noise is reduced more for the EPR4 than for the PR4, where the EPR4 has more convolution steps compared to the PR4. The noise is reduced more for the EEPR4 than for the EPR4, where the EEPR4 has more convolution steps compared to the EPR4. Accordingly, the noise can further be reduced by increasing the convolution steps, but when the convolution steps are increased, the number of registers required in the ML detector 82 also increases.
When determining the number of registers required, the number of convolution steps may be denoted by T, paths 0 and 1 are provided for each step, and by taking into consideration the combination of such paths, it becomes necessary to provide 2.sup.(T+1) paths. The number of registers required in 1 path is normally 5·(T+1), ·2.sup.(T+1) and thus the number R of registers required for the paths can be described by the following formula (1).
R=5·(T+1)·2.sup.(T+1) (1)
For PR4, the number T of convolution steps is "1". Thus, from the formula (1) above, the number R of registers required for the PR4 becomes:
R=5·(1+1)·2.sup.1+1 =5·2·2.sup.2 =40.
According to the EPR4, the number T of convolution steps is "2", and from the formula (1) the number R of registers required from the EPR4 becomes 120. According to the EEPR4, the number T of convolution steps is "3", and from the formula (1), the number R of registers required for the EEPR4 becomes 320. In other words, the number R of registers that are required increases exponentially as the number T of convolution steps increase.
Therefore, when using the PR technique, the number of convolution steps becomes small if a small circuit scale is used, thereby increasing the noise and more easily generating errors. On the other hand, the circuit scale will become extremely large if the noise is to be reduced.
The FDTS/DF technique has been proposed to eliminate the above problems of the PR technique (the increased equalization loss, the increased correlation noise and the considerably increased circuit scale).
FIG. 16 is a block diagram showing construction of the reproducing system employing the FDTS/DF technique.
The head reproduced signal is supplied to a feedforward filter 91 from an input terminal IN. The feedforward filter 91 carries out a wave-shaping process with respect to the head reproduced signal so that the level of the head reproduced signal will not affect the preceding signal. The feedforward filter 91 also equalizes the target waveform by controlling the waveform interference to the subsequent signal to be constant. The signal which is equalized to the target waveform by the feedforward filter 91 is supplied to a subtracter 92.
The subtracter 92 subtracts an output signal which is output from an output terminal OUT and is received via a feedback filter 93 from the signal received from the feedforward filter 91. An output signal of the subtracter 92 is supplied to a FDTS processor 94.
The feedback filter 93 multiplies a waveform interference coefficient by the output signal that is output via the output terminal OUT. The feedback filter 93 also obtains a waveform interference quantity of the preceding signal and the waveform interference quantity of the subsequent signal. The output signal of this feedback filter 93 is supplied to the subtracter 92.
The FDTS processor 94 obtains a mean-square error between an anticipated value under a noise-free condition and the signal which is output from the subtracter 92, and outputs a most likely path out of the possible paths which are arranged in a tree format. The output signal of the FDTS processor 94 is output via the output terminal OUT and is also supplied to the feedback filter 93.
FIG. 17 shows an equalization loss versus normalized frequency characteristic of the FDTS/DF feedforward filter. More particularly, FIG. 17 shows the equalization loss with respect to the normalized frequency for a case where an impulse response Y(D) of the feedforward filter 91 is set to Y(D)=1+D+(1/2)D 2 +(1/4)D 3 . . . and a normalized line density K of an input signal is set to 3.0, 2.5 and 2.0. In FIG. 17, the smaller the normalized line density, the smaller the equalization loss. In addition, the equalization loss can be set below 2 dB to a relatively low value at the normalized line density of 2.0, as shown in FIG. 17.
FIG. 18 shows another equalization loss versus normalized frequency characteristic of the FDTS/DF feedforward filter. More particularly, FIG. 18 shows the equalization loss with respect to the normalized frequency for a case where the impulse response Y(D) of the feedforward filter 91 is set to Y(D)=1+1.5D+D 2 +0.5D 3 +(1/4)D 4 . . . and the normalized line density K of the input signal is set to 3.0, 2.5 and 2.0. In FIG. 18, the smaller the normalized line density, the smaller the equalization loss. In addition, the equalization loss can be set below 2 dB to a relatively low value at the normalized line density of 2.0, as shown in FIG. 18.
Accordingly, the equalization loss of the feedforward filter 91 can be set relatively small as shown in FIGS. 17 and 18 by the FDTS/DF, and the equalization loss is small compared to that obtained by the PR4, EPR4 and EEPR4 described in conjunction with FIG. 12.
FIG. 19 shows an equalization loss versus frequency characteristic for the PR4, EPR4, EEPR4 and FDTS/DF. As may be seen from FIG. 19, a characteristic FDTS1 which is obtained by the FDTS/DF using the feedforward filter having the characteristic shown in FIG. 17 has a small equalization loss for all normalized line densities as compared to that obtained using the PR4. In addition, a characteristic FDTS2 which is obtained by the FDTS/DF using the feedforward filter having the characteristic shown in FIG. 18 has a small equalization loss for all normalized line densities as compared to that obtained using any of the PR4, EPR4 and EEPR4, thereby making it possible to reduce the correlation noise compared to the PR4, EPR4 and EEPR4.
According to the conventional reproducing system employing the PR technique, the number of convolution steps is reduced if the circuit is realized on a small circuit scale. However, the use of a small circuit scale also increases the noise and errors are generated more easily. On the other hand, to reduce the noise, the circuit must be realized on an extremely large circuit scale. In this latter case, it would require further size reduction of mechanical parts in order to secure a sufficiently large mounting space for the large scale circuits, but there is a limit to size reduction for the mechanical parts. Accordingly, a rather large mounting space is still required.
In addition, if the path length is short, it is possible to reduce the equalization loss and the correlation noise. However, the short path length will deteriorate the performance of the ML detector, and then the error propagation becomes large.
The object of the present invention is to provide a signal reproducing method and a signal reproducing apparatus which can suppress the equalization loss and the correlation noise, but will not deteriorate the performance of the ML detector.
SUMMARY OF THE INVENTION
An input signal containing information is reproduced by generating a first signal using a first selected number of convolutions, generating a second signal using a second selected number of convolutions, and combining the first and second signals to identify the information in the input signal. The first and second signals can be processed by adding or subtracting them, depending on the circuit configuration, and using partial response maximum likelihood techniques to identify the signal information. With this invention, the number of convolution steps is reduced, and it is possible to reduce equalization loss and correlation noise using circuits having a small circuit scale. When applied to a disk drive, it is possible to improve reliability, reduce circuit scale and reduce the size and weight of the drive. It is also possible to obtain a high-density recording due to the reduced error rate realized by this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the construction of a first embodiment of a signal reproducing apparatus according to the present invention.
FIG. 2 is a block diagram showing the construction of a second embodiment of the signal reproducing apparatus according to the present invention.
FIG. 3 is a block diagram showing the construction of a DFE detector of the second embodiment of the signal reproducing apparatus.
FIG. 4 is a block diagram showing the construction of a third embodiment of the signal reproducing apparatus according to the present invention.
FIG. 5 is a block diagram showing the construction of the fourth embodiment of the signal reproducing apparatus according to the present invention.
FIG. 6 is a block diagram showing the construction of a fifth embodiment of the signal reproducing apparatus according to the present invention.
FIG. 7 is a block diagram showing the construction of a sixth embodiment of the signal reproducing apparatus according to the present invention.
FIG. 8 is a diagram showing the general construction of a hard disk unit.
FIG. 9 is a block diagram showing the construction of a reproducing system employing the PR technique.
FIGS. 10A-10C are diagrams showing impulse response characteristics of the PR technique.
FIG. 11 is a diagram showing equalization losses with respect to normalized line density of recording information for the PR4, EPR4 and EEPR4.
FIG. 12 is a diagram showing equalization gains with respect to normalized frequency for the PR4, EPR4 and EEPR4.
FIG. 13 is a diagram showing S/N ratio losses with respect to normalized line density for the PR4, EPR4 and EEPR4.
FIG. 14 is a diagram showing S/N ratios at a portion of an ML detector with respect to normalized line density of recording information for the PR4, EPR4 and EEPR4.
FIG. 15 is a diagram showing peak signal/RMS noise with respect to normalized line density of recording information for the PR4, EPR4 and EEPR4.
FIG. 16 is a block diagram showing the construction of a reproducing system employing FDTS/DF technique.
FIG. 17 is a diagram showing equalization loss versus the normalized frequency characteristic of the FDTS/DF feedforward filter.
FIG. 18 is another diagram showing equalization loss versus the normalized frequency characteristic for the FDTS/DF feedforward filter.
FIG. 19 is a diagram showing equalization losses versus the frequency characteristic for the PR4, EPR4, EEPR4 and FDTS/DF.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the construction of a first embodiment of a signal reproducing apparatus according to the present invention. The signal reproducing apparatus 1 corresponds to a reproducing system of a hard disk unit, which reproducing system includes a reproducing equalizer and an ML detector. The signal reproducing apparatus 1 of this embodiment includes a feedforward filter FFF2, a subtracter 3, an ML detector 4, a provisional detector 5, and a control circuit 8. The provisional detector 5 includes a Fixed Delay Tree Search (FDTS) processor and a Feed Back Filter (FBF) 7, and the control circuit 8 includes a detector 9 and a controller 10.
A head reproduced signal from a head is supplied to an input terminal IN and is supplied to the feedforward filter 2. The feedforward filter 2 carries out a wave-shaping process with respect to the head reproduced signal so that the level of the head reproduced signal will not affect the preceding signal. The feedforward filter 2 also carries out an equalization of the target waveform by controlling the waveform interference to the subsequent signal constant.
A response at the feedforward filter 2 can be described by the following formula (2), where a n denotes the head reproduced signal, W n denotes an output signal of the feedforward filter 2, and g t denotes a weighting with respect to the impulse response. ##EQU1##
For example, in the case of the PR4 where the impulse response includes the element (1+D); g 0= 1 and g 1=1 . In the case of the EPR4 where the impulse response includes the element (1+D) 2 ; g 0= 1, g 1 =2 and g 3 =1.
The output signal W n which is equalized to the target waveform in the feedforward filter 2 is supplied to the subtracter 3. The subtracter 3 subtracts an output signal X n of the provisional detector 5 from the output signal W n of the feedforward filter 2, and outputs a subtraction result Y n .
The subtraction result Y n from the subtracter 3 is supplied to the ML detector 4 and the provisional detector 5. The ML detector 4 carries out the convolution in τ bits, and outputs a signal a n . The ML detector 4 is connected to an output terminal OUT, and the signal a n detected by the ML detector 4 is output via the output terminal OUT and supplied to a decoder.
The FDTS processor 6 detects the subtraction result Y n output from the subtracter 3, and the feedback filter 7 carries out a weighting with respect to a provisional judgment result a n which is output from the FDTS processor 6.
The FDTS processor 6 obtains a mean-square error between an anticipated value under a noise-free condition and the subtraction result Y n which is output from the subtracter 3, and outputs a most likely path out of the possible paths which are arranged in a tree format. This most likely path is output as the provisional judgment result a n and is supplied to the feedback filter 7. The output signal of the feedback filter 7 is denoted by X n , and the response of the feedback filter 7 with respect to the provisional judgment result a n of the FDTS processor 6 can be described by the following formula (3), where a n-u denotes the provisional judgment result from the FDTS processor 6, g u denotes the weighting coefficient, and t denotes the convolution length (t<T) of the subtraction result Y n which is input to the ML detector 4. ##EQU2##
The output signal X n of the feedback filter 7 is supplied to the subtracter 3, and is subtracted from the output signal W n of the feedforward filter 2 as described above.
A description will now be given of the response of the subtracter 3. The subtraction result Y n from the subtracter 3 is obtained by subtracting the output signal X n of the feedback filter 7 from the output signal W n of the feedforward filter 2, and can be described by the following formula (4).
Y.sub.n =W.sub.n -X.sub.n (4) (4)
By substituting the formula (2) into the formula (4) for the output signal W n of the feedforward filter 2, and substituting the formula (3) into the formula (4) for the output signal X n of the feedback filter 7, the subtraction result Y n from the subtracter 3 can be described by the following formula (5). ##EQU3##
If it is assumed that the provisional judgment result a n from the FDTS processor 6 is correct, the formula (5) can be rewritten as the following formula (6). ##EQU4##
The detector 9 in the control circuit 8 compares the head reproduced signal with a sampling clock, and detects a ratio of the frequency of the head reproduced signal and the sampling clock frequency. The controller 10 varies weighting coefficients g of the FDTS processor 6, the ML detector 4, the feedback filter 7 and the feedforward filter 2 to optimum values with respect to the frequency of the head reproduced signal, depending on the ratio detected by the detect or 9.
The optimum processing available for a head reproduced signal with a highly accurate detection is achieved by varying the weighting coefficients g of the FDTS processor 6, the ML detector 4, the feedback filter 7 and the feedforward filter 2 to optimum values with respect to the frequency of the head reproduced signal by the control circuit 8.
According to this embodiment, the output signal W n of the feedforward filter 2 is subjected to the FDTS/DF processing by the provisional detector 5, which is made up of the FDTS processor 6 and the feedback filter 7. As a result, the equalization loss and the correlation noise are suppressed in the subtraction result Y n output from the subtracter 3. By suppressing this subtraction result Y n from the ML detection in the ML detector 4, it is possible to reduce the error of the output signal a n , because the equalization loss and the correlation loss are suppressed beforehand.
For example, if the convolution bit length T of the feedforward filter 2 is "4", the provisional detector 5 eliminates the waveform interference of 2 bits, and the convolution bit length τ of the ML detector 4 is "2", then the ML detector 4 can carry out the detection using the EPR4. In this case, the number of registers that are required in the ML detector 4 can be found to be 120 from the formula (1) described above. But if the provisional detector 5 were not provided, a convolution bit length T of the ML detector 4 will be "4", and in this case, the number of registers that are required in the ML detector 4 will be 800 from the formula (1). For this reason, it may be seen that this embodiment can reduce the circuit scale and also reduce the equalization loss and the correlation noise. Accordingly, this embodiment can obtain a highly accurate reproduced signal. When this embodiment is applied to a disk unit, for example, it is possible to improve the reliability, reduce the circuit scale, and reduce the size and weight of the disk unit. In addition, it is possible to obtain a high-density recording due to the reduced error rate realized by this embodiment.
Also, with this first embodiment, it is possible to simplify the ML detection process because the ML detection is carried out with respect to the second waveform-interference waveform which is reduced to τ bits from the T-bit first waveform-interference waveform. In addition, since the τ-bit second waveform-interference waveform is generated by subtracting the (T-τ)-bit third waveform-interference waveform from the T-bit first waveform interference waveform, the ML detection is carried out with respect to the signal which is suppressed of the noise and loss beforehand. As a result, the quantization loss and the correlation noise can be suppressed at the time of the ML detection.
Further, the provisional detection can be made using the existing FDTS and the existing Decision Feedback Equalization (DFE). This feature also makes it possible to obtain a highly accurate reproduced signal. Also, when applied to a disk drive, the benefits discussed above are also achieved.
FIG. 2 is a block diagram showing the construction of a second embodiment of the signal reproducing apparatus according to the present invention. In FIG. 2, those parts which are the same as those corresponding parts in FIG. 1 are designated by the same reference numerals, and a description thereof will be omitted.
The construction of the provisional detector of this second embodiment differs from that of the first embodiment. In this embodiment, a signal reproducing apparatus 11 includes a provisional detector 12 having a (DFE) detector 13 and the feedback filter 7. A control circuit 14 includes the detector 9 and a controller 15.
The DFE detector 13 calculates an estimated waveform interference quantity from the preceding signal, and subtracts the estimated waveform interference quantity from the subtraction result Y n which is obtained from the subtracter 3 so as to obtain a calculation result. In addition, the DFE detector 13 makes a binary value judgment with respect to the calculation result, thereby making the provisional detection.
FIG. 3 is a block diagram showing the construction of the DFE detector 13 of the second embodiment. The DFE detector 13 includes a subtracter 114, a binary value judging circuit 115, a feedback filter 116 and a delay circuit 117.
The subtracter 114 subtracts an output signal ISIR of the feedback filter 116 from the subtraction result Y n (rk in FIG. 3), which is received from the subtracter 3. The output signal of the feedback filter 116 indicates the estimated waveform interference quantity. An output signal of the subtracter 114 is supplied to the binary value judging circuit 115, which binarizes the signal value into a binary value "+1" or "-1" depending on the level of the output signal of the subtracter 114. An output signal of the binary value judging circuit 115 is output via the delay circuit 117, and is supplied to the feedback filter 7.
The detector 9 compares the head reproduced signal with a sampling clock, and detects a ratio of the frequency of the head reproduced signal and the sampling clock frequency. The controller 15 varies weighting coefficients "g" of the DFE detector 13, the ML detector 4, the feedback filter 7 and the feedforward filter 2 to optimum values with respect to the frequency of the head reproduced signal, depending on the ratio detected by the detector 9. Thus, the optimum processing available for a head reproduced signal with a highly accurate detection can be achieved by varying the weighting coefficients "g" of the DFE detector 13, the ML detector 4, the feedback filter 7 and the feedforward filter 2 to optimum values with respect to the frequency of the head reproduced signal by the control circuit 14.
According to this embodiment, a provisional detection is made by the DFE detector 13, similarly to the first embodiment. The feedback filter 7 carries out a weighting with respect to the result of the provisional detection, and supplies the signal X n to the subtracter 3. The subtracter 3 subtracts the signal X n from the output signal W n of the feedforward filter 2, and outputs the subtraction result Y n by making the conversion into the waveform-interference waveform of τ bits. The subtraction result Y n is supplied to the ML detector 4, which carries out a τ-bit convolution. As a result, the equalization loss and the correlation noise are suppressed in the provisional detector 12, and the effects of the equalization detector 12, and the effects of the equalization loss and the correlation noise can be suppressed even if the detection made by the ML detector 4 has a small number of convolution steps, that is, a small circuit scale. For this reason, it is possible to obtain a signal reproducing apparatus which can reduce the equalization loss and the correlation noise using circuits having a small circuit scale. Accordingly, this embodiment can obtain a highly accurate reproduced signal. When this embodiment is applied to a disk unit, for example, it is possible to improve the reliability, reduce the circuit scale, and reduce the size and weight of the disk unit. In addition, it is possible to obtain a high-density recording due to the reduced error rate realized by this embodiment.
Also, with this second embodiment, it is possible to simplify ML detection process because the ML detection is carried out with respect to the third waveform-interference waveform which is reduced to τ bits from the T-bit first waveform-interference waveform. In addition, since the τ-bit third waveform-interference waveform is generated by subtracting the (T-τ)-bit second waveform-interference waveform from the T-bit first waveform-interference waveform, the ML detection is carried out with respect to the signal which is suppressed of the noise and loss beforehand.
Further, in this embodiment, it is also possible to carry out an optimum weighting with respect to the second waveform-interference waveform in the feedback filter. Thus, the provisional detection is highly accurate. Additionally, a highly accurate reproduced signal is obtained.
Finally, the provisional detection can be made using the existing FDTS and the existing DFE. This feature also makes it possible to obtain highly accurate reproduced signals. Also, when applied to a disk drive, the benefits discussed above are also achieved.
FIG. 4 is a block diagram showing the construction of a third embodiment of the signal reproducing apparatus according to the present invention. In FIG. 4, those parts which are the same as those corresponding parts in FIG. 1 are designated by the same reference numerals, and a description thereof will be omitted.
In this embodiment a signal input position with respect to a provisional detector 22 which makes the provisional detection is different from that of the first embodiment shown in FIG. 1. In this embodiment, the provisional detector 22 includes a FDTS processor 23 and a feedforward filter 24. The FDTS processor 23 carries out a FDTS processing with respect to the output signal W n of the feedforward filter 2. The feedforward filter 24 carries out a weighting with respect to an output signal of the FDTS processor 23.
With respect to the signal subjected to the T-bit convolution in the feedforward filter 2, the FDTS processor 23 carries out a (T-τ)-bit convolution, and supplies a resulting signal to the feedforward filter 24. The feedforward filter 24 carries out a weighting on the output signal of the FDTS processor 23, and an output signal of the feedforward filter 24 is supplied to the subtracter 3.
According to this embodiment, the provisional detector 22 suppresses the equalization loss and the correlation noise, similarly to the first and second embodiments, and thus, it is possible to reduce the equalization loss, the correlation noise and the error rate. Accordingly, this embodiment can obtain a highly accurate reproduced signal. When applied to a disk unit, the benefits discussed above are also achieved.
Additionally, with this third embodiment it is possible to simplify the ML detection process because the ML detection is carried out with respect to the fourth waveform-interference waveform which is reduced to r bits from the T-bit first waveform-interference waveform. In addition, since the i-bit fourth waveform-interference waveform is generated by subtracting the (T-τ)-bit third waveform interference waveform from the T-bit first waveform interference waveform, the ML detection is carried out with respect to the signal which is suppressed of the noise and loss beforehand. As a result, the quantization loss and the correlation noise can be suppressed at the time of the ML detection.
In this embodiment, it is also possible to carry out an optimum weighting with respect to the third waveform-interference waveform in the second filter, thereby enabling a highly accurate provisional detection. For this reason also, a highly accurate reproduced signal can be obtained.
Further, an optimum processing dependent upon the input signal frequency and a highly accurate detection become possible by varying the coefficient of the feedforward filter, the provisional detector, the feedback filter and the ML detection means to optimum values with respect to the input signal frequency by the control means.
Furthermore, it is possible to reduce the number of convolution steps of the ML detector 4. As a result, it is possible to reduce the circuit scale as a whole.
FIG. 5 is a block diagram showing the construction of a fourth embodiment of the signal reproducing apparatus according to the present invention. In FIG. 5, those parts which are the same as those corresponding parts in FIG. 4 are designated by the same reference numerals, and a description thereof will be omitted.
In a provisional detector 32 of a signal reproducing apparatus 31 of this embodiment, a DFE detector 33 which is similar to the DFE detector 13 of the second embodiment shown in FIG. 3 is used in place of the FDTS processor 23 of the provisional detector 22 of the third embodiment shown in FIG. 4.
According to this embodiment, the provisional detector 32 suppresses the equalization loss and the correlation noise, similarly to the first through third embodiments, and thus, it is possible to reduce the equalization loss, the correlation noise and the error rate. Accordingly, this embodiment can obtain a highly accurate reproduced signal. When this embodiment is applied to a disk unit, for example, it is possible to improve the reliability, reduce the circuit scale, and reduce the size and weight of the disk unit. In addition, it is possible to realize a high-density recording due to the reduced error rate realized by this embodiment.
Furthermore, it is possible to reduce the number of convolution steps of the ML detector 4. As a result, it is possible to reduce the circuit scale as a whole.
FIG. 6 is a block diagram showing the construction of a fifth embodiment of the signal reproducing apparatus according to the present invention. In FIG. 6, those parts which are the same as those corresponding parts in FIG. 1 are designated by the same reference numerals, and a description thereof will be omitted.
In a signal reproducing apparatus 41 of this embodiment, the construction of a provisional detector 42 differs from the provisional detector 5 of the first embodiment shown in FIG. 1. In this embodiment, the provisional detector 42 includes a feedforward filter 43, a FDTS processor 44 and the feedback filter 7, which functions more like a feedforward filter in this embodiment.
The feedforward filter 43 has a construction similar to that of the feedforward filter 2. The feedforward filter 43 carries out a wave-shaping process with respect to the head reproduced signal so that the level of the head reproduced signal will not affect the preceding signal, and carries out an equalization of the target waveform by controlling the waveform interference to the subsequent signal constant. The characteristic of the feedforward filter 43 is set to be different from that of the feedforward filter 2, so that the feedforward filter 43 has an optimum characteristic with respect to the FDTS processing that is carried out by the FDTS processor 44. For example, the value of the weighting coefficient g n in the formula (2) is set to a value corresponding to the number of convolution steps in the FDTS processor 44.
An output signal of the feedforward filter 43 is supplied to the FDTS processor 44. The FDTS processor 44 has a construction similar to that of the FDTS processor 6 described above. The FDTS processor 44 carries out a (T-τ)-bit convolution with respect to the output signal of the feedforward filter 43, and an output of this FDTS processor 44 is supplied to the subtracter 3 via the feedback filter 7.
A control circuit 45 includes the detector 9 and a controller 46. The detector 9 compares the head reproduced signal with the sampling clock, and detects the ratio of the frequency of the head reproduced signal and the sampling clock frequency. The controller 46 varies the weighting coefficients g of the FDTS processor 44, the ML detector 4, the feedforward filter 43, the feedback filter 7 and the feedforward filter 2 to optimum values with respect to the frequency of the head reproduced signal, depending on the ratio detected by the detector 9. Thus, the optimum processing available for a head reproduced signal with highly accurate detection can be achieved by varying the weighting coefficients g of the FDTS processor 44, the ML detector 4, the feedforward filter 43, the feedback filter 7 and the feedforward filter 2 to optimum values with respect to the frequency of the head reproduced signal by the control circuit 45.
According to this embodiment, the provisional detector 42 suppresses the equalization loss and the correlation noise, similarly to the first through fourth embodiments, and thus, it is possible to reduce the equalization loss, the correlation noise and the error rate. Accordingly, this embodiment can also obtain a highly accurate reproduced signal. When applied to a disk unit, the benefits discussed above are achieved.
Furthermore, it is possible to reduce the number of convolution steps of the ML detector 4 with this embodiment. As a result, it is possible to reduce the circuit scale as a whole.
In addition, the provisional detector 42 can carry out a highly accurate provisional detection, because the feedforward filter 43 is provided independently to directly receive and process the head reproduced signal, and also because the feedforward filter 43 can be set to have an optimum characteristic with respect to the FDTS processing that is carried out in the FDTS processor 44. As a result, the equalization loss and the correlation noise can be suppressed more efficiently.
FIG. 7 is a block diagram showing a sixth embodiment of the signal reproducing apparatus according to the present invention. In FIG. 7, those parts which are the same as those corresponding parts in FIG. 6 are designated by the same reference numerals, and a description thereof will be omitted.
In a signal reproducing apparatus 51 of this embodiment, the construction of a provisional detector 52 is different from that of the provisional detector 42 of the fifth embodiment shown in FIG. 6. In the provisional detector 52 of this embodiment, a DFE detector 53 similar to the DFE detector 13 of the second embodiment shown in FIG. 3 is used in place of the FDTS processor 44 of the provisional detector 42 of the fifth embodiment shown in FIG. 6.
In addition, a control circuit 54 includes the detector 9 and a controller 55. The detector 9 compares the head reproduced signal with the sampling clock and detects the ratio of the frequency of the head reproduced signal and the sampling clock frequency. The controller 55 varies the weighting coefficients "g" of the DFE detector 53, the ML detector 4, the feedforward filter 43, the feedforward filter 7 and the feedforward filter 2 to optimum values with respect to the frequency of the head reproduced signal, depending on the ratio detected by the detector 9.
The optimum processing available for a head reproduced signal with a highly accurate detection can be achieved by varying the weighting coefficients "g" of the DFE detector 53, the ML detector 4, the feedforward filter 43, the feedback filter 7 and the feedforward filter 2 to optimum values with respect to the frequency of the head reproduced signal by the control circuit 54.
According to this embodiment, the provisional detector 52 suppresses the equalization loss and the correlation noise, similarly to the fifth embodiment, and thus, it is possible to reduce the equalization loss, the correlation noise and the error rate. Accordingly, this embodiment can also obtain a highly accurate reproduced signal, and when applied to a disk unit, achieve the benefits discussed above.
Furthermore, it is possible to reduce the number of convolution steps of the ML detector 4. As a result, it is possible to reduce the circuit scale as a whole.
In addition, the provisional detector 52 can carry out a highly accurate provisional detection, because the feedforward filter 43 is provided independently to directly receive and process the head reproduced signal, and the feedforward filter 43 can be set to have an optimum characteristic with respect to the processing that is carried out in the DFE detector 53. As a result, the equalization loss and the correlation noise can be suppressed more efficiently.
While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims.
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The present invention relates to a signal reproducing method and a signal reproducing apparatus for reproducing a signal recorded by a high-density recording. The invention avoids deteriorating the performance of an ML detector while suppressing the equalization loss and the correlation noise. The signal reproducing method includes steps of generating a first signal using a first selected number of convolutions, generating a second signal using a second selected number of convolutions, and combining the first and second signals to identify the information in the input signal. The first and second signals can be processed by adding or subtracting the first and second signals, depending on the circuit configuration. With this invention, the number of convolution steps is reduced, and it is possible to reduce equalization loss and correlation noise using circuits having a small circuit scale. When applied to a disk drive, it is possible to improve reliability, reduce circuit scale and reduce the size and weight of the drive. It is also possible to obtain a high-density recording due to the reduced error rate realized by this invention.
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PRIORITY
This application claims priority to U.S. 61/089,786 filed on Aug. 18, 2008.
CROSS REFERENCE TO RELATED APPLICATIONS
Applications and patent Ser. Nos. 09/924,392, 10/666,897, 10/746,957, 10/799,549, 10/825,912, 10/825,974, 11/022,078, 11/025,363, 11/025,680, 11/025,681, 11/025,692, 11/025,693, 11/084,486, 11/121,737, 11/187,213, U.S. 20050166834, U.S. 20050161773, U.S. 20050163692, Ser. Nos. 11/053,775, 11/053,785, 11/054,573, 11/054,579, 11/054,627, 11/068,222, 11/188,081, 11/253,525, 11/254,031, 11/257,517, 11/257,597, 11/393,629, 11/398,910, 11/472,087, 11/788,153, 11/858,838, 11/960,418, 12/119,387, 60/820,438, 60/811,311, 61/089,786, Ser. Nos. 12/171,200, 12/119,387, 60/847,767, 60/944,369, 60/949,753, U.S. Pat. No. 7,018,484, U.S. Pat. No. 7,037,806, U.S. Pat. No. 7,135,699, U.S. Pat. No. 7,199,015, all held by the same assignee, contain information relevant to the instant invention and are included herein in their entirety by reference. References, noted at the end, are included herein in their entirety by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to a device structure for up and down conversion of radiation, typically solar, wherein high energy wavelengths are down converted to lower energy and low energy wavelengths are up converted to higher energy to improve adsorption by a photovoltaic device.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
As an alternative approach to multiple junction solar cells where specific materials are matched to discrete portions of the solar spectrum, conversion works on the principle of moving parts of the spectrum to the wavelength band of a single junction cell. For example it is widely accepted that a single junction, single crystal silicon solar cell has an optimum performance in the wavelength range 500 to 1,100 nm, whilst the solar spectrum extends from 400 nm to in excess of 2500 nm.
Rare earths, the lanthanide series, have long been known for the unique optical properties in which the incomplete, 4f shells exhibit multiple optical transitions many of which lie within the solar spectrum. An example of some of these optical transitions are:
Er: 410, 519, 650, 810, 972, 1,529 nm
Yb: 980 nm
Tb: 485 nm
As used herein [RE1, RE2, . . . RE10] are chosen from the lanthanide series of rare earths from the periodic table of elements consisting of { 57 La, 58 Ce, 59 Pr, 60 Nd, 61 Pm, 62 Sm, 63 Eu, 64 Gd, 65 Tb, 66 Dy, 67 Ho, 68 Er, 69 Tm, 70 Yb and 71 Lu} plus yttrium, 39 Y, and scandium, 21 Sc, are included as well for the invention disclosed.
A more complete list can be found in the technical literature. In addition certain of these rare earths, sometimes in combination with one or more rare earths, can absorb light at one wavelength (energy) and re-emit at another (energy). This is the essence of conversion; when the incident energy per photon is less than the emission energy per photon the process is referred to as up conversion. Down conversion is the process in which the incident energy per photon is higher than the emission energy per photon. An example of up conversion is Er absorbing at 1,480 nm and exhibiting photoluminescence at 980 nm.
One concept was patented in U.S. Pat. No. 3,929,510; more recent work in this field has mainly focused on the addition of rare earths to phosphorescent compounds. The historical approaches however add a conversion layer to either a completed solar cell or module with the majority also requiring an additional reflective component to return the converted spectrum back into the cell so that it can contribute to the generated photocurrent. U.S. Pat. No. 7,184,203 discloses up and down conversion with a rare earth compound comprising a rare earth element and at least one other element selected from chalcogens, halogens, nitrogen, phosphorus and carbon; wherein the rare earth compound is not mixed with compounds containing other rare earth elements and wherein the rare earth compound is irradiated at a sufficient intensity to heat the rare earth compound to facilitate electronic transitions. U.S. Pat. No. 7,184,203 does not teach or suggest using a rare earth compound in conjunction with a photovoltaic device; U.S. Pat. No. 7,184,203 teaches away from the use of a rare earth compound with relatively low intensity radiation at room temperature for up or down conversion.
BRIEF SUMMARY OF THE INVENTION
The use of rare-earth (REO, N, P) based materials to covert long wavelength photons to shorter wavelength photons that can be absorbed in a photovoltaic device (up-conversion) and (REO, N, P) materials which can absorb a short wavelength photon and re-emit one (downshifting) or more longer wavelength photons is disclosed. The wide spectral range of sunlight overlaps with a multitude of energy transitions in rare-earth materials, thus offering multiple up-conversion pathways. The refractive index contrast of rare-earth materials with silicon enables a DBR with >90% peak reflectivity and a stop band greater than 150 nm. FIG. 1 is a schematic of a silicon solar cell with an upconverting layer.
In contrast the instant invention discloses a process to manufacture the rare earths in a thin film format that is materially compatible with the underlying silicon semiconductor. One advantage of this is the control it provides over the process both in tuning a material to particular wavelengths and in reproducing the process in a manufacturing environment. Optionally, rare earth oxides, nitrides, and phosphides and/or combinations thereof may be employed. As used herein the terms, “oxides” and “rare-earth oxide[s]” are inclusive of rare earth oxides, nitrides, and phosphides and/or combinations thereof.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a schematic illustration of prior art.
FIG. 2 is a schematic illustration of rare earth oxide on silicon.
FIG. 3 is a schematic illustration of a rare earth oxide DBR.
FIG. 4 is a schematic illustration of one embodiment with a RE oxide and reflector.
FIG. 5 is a schematic illustration of one embodiment with a RE oxide and a Distributed Bragg Reflector (DBR).
FIG. 6 is a schematic illustration of one embodiment with a RE oxide separating two solar cells.
FIG. 7 is a schematic illustration of one embodiment with a RE oxide and a transparent substrate.
FIG. 8 is a schematic illustration of one embodiment with a RE oxide and a transparent substrate.
FIG. 9 is a TEM of a silicon/rare earth DBR.
FIG. 10 shows photoluminescence data from an up-conversion and down conversion structures.
FIG. 11 shows photoluminescence data versus Yb mole fraction.
FIG. 12 shows diffraction data for binary and ternary rare earths.
FIG. 13 is a plot of % reflectivity for ErO on silicon.
FIGS. 14A and B show x-ray data for rare earth oxide on a transparent substrate.
FIGS. 15A and B are schematic illustrations of several embodiments.
FIGS. 16A , B and C are schematic illustrations of several embodiments.
FIGS. 17A , B and C are schematic illustrations of several embodiments.
FIG. 18 is a schematic illustration of several embodiments.
FIG. 19 is a schematic illustration of possible spectral conversion pathways using rare-earth ions.
FIG. 20 is a (Er (x) Yb (1-x) ) 2 O 3 luminescence spectrum from 1480 nm laser illumination.
FIG. 21 is a plot of photocurrent from a silicon detector due to up-conversion in an (Er (x) Yb (1-x) ) 2 O 3 layer.
DETAILED DESCRIPTION OF THE INVENTION
Rare-earth oxides may be added to a semiconductor structure in a single step at the conclusion of the manufacture of epitaxial silicon; optionally, not. This placement in the process flow also facilitates the same layer being used for passivation of the silicon surface; optionally, a rare-earth layer may be designed as an anti reflective coating. The ability of a rare earth oxide to do additional functions has been previously reported though frequently not using a single crystal material or multiple rare earths; note FIG. 1 showing a prior art example. It is important to note that rare earth oxides do not need epitaxial silicon; rare earth oxides perform all of the same tasks when placed onto a wafer of silicon as part of an overall production of a solar cell, with a proviso that any process used must produce a single crystal oxide; optionally large grain, small grain, micro grain and nano grain rare-earths are also disclosed.
Examples of device structures utilizing layers of single crystal rare earth oxides to perform the tasks of up conversion, and/or down conversion along with, optionally, designing in required optical and/or anti reflective properties are now given. In embodiments of the instant invention, x, y and z range from 0 up to and including 1. A substrate may be silicon, poly or multi-crystalline silicon, silicon dioxide or glass; as used herein multi-crystalline includes poly, micro and nano crystalline. The number of REO/Si(1-y)Ge(y) bilayers may range from one to more than one hundred. “A layer” also comprises multiple layers, optionally. REO, Si(1-x)Ge(x), Si(1-y)Ge(y), and Si(1-z)Ge(z) layers are optionally single crystal, multi-crystalline or amorphous layers and are, optionally, optically active dielectrics compatible with semiconductor processing techniques. As used herein a “REO” layer contains two or more elements, at least one chosen from the Lanthanide series plus Scandium and Yttrium and at least one chosen from oxygen and/or nitrogen and/or phosphorous and/or mixtures thereof; structures are not limited to specific rare-earth elements cited in examples. Rare earth material are represented as (RE1+RE2+ . . . REn) m O n where the total mole fraction of rare earths, 1 . . . n, is one. In some embodiments, in addition to the RE (1, 2, . . . n) an alloy may include Si and/or Ge and/or C; optionally an oxide may be an oxynitride or oxyphosphide; m and n may vary from greater than 0 to 5.
Example 1
In this embodiment a rare earth oxide is performing the task of either down conversion or up conversion and may be functioning as a distributed Bragg reflector, DBR.
By setting the thickness of the rare earth oxide according to a formula
nd=mλ/ 4 (1)
where n=refractive index at λ, d=layer thickness and λ=wavelength at which the optical characteristics of the layer are specified and m is an odd integer; optionally, the same layer can be considered to be an anti reflective coating.
Example 2
FIG. 3 illustrates several embodiments; a rare earth oxide is performing a task of down conversion. In some embodiments a rare earth oxide has a thickness conforming to nd=mλ/4, (where n=refractive index at λ, d=layer thickness, m is an odd integer and λ=wavelength at which the optical characteristics of the layer are specified). Additionally a silicon layer has a thickness also conforming to nd=mλ/4. The combination of multiple repeats of these two layers is nominally termed a Distributed Bragg Reflector (DBR) and may be designed to be anti-reflective layer over an expanded range when compared to the single layer approach of example 1. In this example a silicon layer within the DBR is doped electrically to conform to the chosen device architecture.
Example 3
FIG. 4 shows an embodiment where a rare earth oxide is performing a task of up conversion. In this example a reflector can be any material that is tuned to be reflective to the wavelengths of the converted spectrum.
Example 4
FIG. 5 shows an embodiment where a rare earth oxide is performing a task of up conversion. In this example a generic reflector of example 3 is replaced by a DBR design to be matched to the converted spectrum and the overall device architecture. The rare earth and silicon layers within the DBR have thicknesses conforming to nd=mλ/4, (where n=refractive index at λ, d=layer thickness, m=an odd integer and λ=wavelength at which the optical characteristics of the layer are specified). In this example a silicon layer within the DBR is doped electrically to conform with the chosen device architecture
Example 5
FIG. 6 shows an embodiment where a rare earth oxide is performing a task of up conversion. A second silicon layer is placed in the device to generate photocurrent from the converted spectrum coming from the up converting rare earth oxide layer.
Example 6
FIG. 7 shows an embodiment where a rare earth oxide is performing a task of down conversion. In this example a rare earth oxide is manufactured as a single crystal on a transparent substrate. The chosen material is substantially transparent to the portion of the spectrum normally used within a silicon based solar cell to generate photocurrent. However in portions of the UV spectrum that are not adsorbed efficiently by the silicon cell, a rare earth oxide performs a task of spectral down conversion. This rare earth oxide—transparent substrate combination may then be used in general proximity to any cell as shown below
Example 7
FIG. 8 shows an embodiment where a rare earth oxide, ReO, is on a transparent substrate but now this structure is used as a virtual substrate for any subsequent growth of additional photovoltaic material, optionally, single crystal or poly crystal or amorphous; FIG. 8 shows an alternative embodiment of the same concept where the [ReO] layer is providing down-conversion of incident UV radiation prior to passage into a solar cell, optionally silicon based or other material system.
In all examples listed herein it is disclosed that a rare earth layer(s) for up converting and/or down converting occurs with one or more layers comprising one or more rare earths in combination with one or more chosen from the group comprising oxygen, nitrogen, phosphorus, silicon, germanium, and carbon. A rare earth layer may be grown on a single crystal substrate or not; the substrate may be silicon or not; a rare earth layer for converting may be transferred to a different substrate for the converting. A rare earth layer may be deposited as single crystal, or multi-crystalline or amorphous; subsequent processing may be required to change a physical state of a rare earth layer to make it suitable for up and/or down converting, such as converting an amorphous layer to a large grained layer. A rare earth layer for up converting and/or down converting may be used in combination with one or more reflectors, Bragg layers, textured layers, or other optical components known to one knowledgeable in the field. In some embodiments a rare earth layer for up converting and/or down converting is also a reflector layer, Bragg layer, and/or textured layer.
In some embodiments a low cost substrate such as soda glass or polycrystalline alumina is used in combination with a rare-earth based structure comprising a diffusion barrier layer, a buffer layer, an active region, an up and/or down layer(s), one or more reflectors, one or more Bragg layers, texturing is optional; one or more layers may comprise a rare-earth. The exact sequence of the layers is application dependent; in some cases sunlight may enter a transparent substrate initially; in other cases a transparent substrate may be interior of multiple layers.
FIG. 9 shows a TEM of silicon—Er 2 O 3 DBR.
FIG. 10 is photoluminescence data from various samples of (Yb x Er y ) m O n showing spectral conversion in single crystal material (top=upconversion, bottom=down conversion) where, optionally, m=2 and n=3.
FIG. 11 shows photoluminescence data from various samples of (Yb (1-y) Er y ) 2 O 3 as a function of y.
FIG. 12 X-ray diffraction data for binary and ternary compounds of rare earths showing how precise control of the chosen compound can be maintained.
FIG. 13 Plot of % Reflectivity for ErO on silicon-non optimized
FIG. 14 is X-ray data for rare earth oxide on transparent substrate showing single crystal nature of the rare earth oxide.
FIG. 15A illustrates several embodiments; in one embodiment rare earth oxide layers are performing the task of up conversion, and Si(1-z)Ge(z) and Si(1-x)Ge(x) layers are photovoltaic energy converting layers with appropriate electrical contacts and doping profiles for such a function. In another embodiment a REO/Si(1-y)Ge(y) composite layer is performing the task of up conversion. In another embodiment rare earth oxide layers are also performing a task of strain balancing, such that the net strain in the REO/Si(1-y)Ge(y) composite layer is effectively reduced over that of a single REO layer of the same net REO thickness grown on the same substrate, thus allowing a greater total thickness of REO to be incorporated into the structure before the onset of plastic deformation. In another embodiment rare earth oxide layers are strain balanced such that a critical thickness of the REO/Si(1-y)Ge(y) composite is not exceeded. In another embodiment REO/Si(1-y)Ge(y) composite layer acts to mitigate propagation of dislocations from an underlying Si(1-x)Ge(x) layer through to the overlying Si(1-z)Ge(z) layer thereby improving the crystallinity and carrier lifetime in the Si(1-z)Ge(z) layer. In another embodiment, the Si(1-x)Ge(x) has a narrower bandgap than the Si(1-z)Ge(z) layer (i.e. x>z) such that the Si(1-z)Ge(z) layer and the Si(1-x)Ge(x) layers form a tandem solar cell. For example, solar radiation impinges upon the Si(1-z)Ge(z) layer first where photons of energy greater than the bandgap of Si(1-z)Ge(z) are absorbed and converted to electrical energy. Photons with energy less than the bandgap of Si(1-z)Ge(z) are passed through to the Si(1-x)Ge(x) layer where they may be absorbed. Some embodiments combine all of the disclosed features for FIG. 15A
In FIG. 15B several embodiments are disclosed; in one embodiment rare earth oxide layers are performing the task of up conversion, and a Si(1-z)Ge(z) layer is a photovoltaic energy converting layer with appropriate electrical contacts and doping profiles for such a function. In one embodiment a REO/Si(1-y)Ge(y) composite layer is performing the task of up conversion. In one embodiment rare earth oxide layers are performing a task of strain balancing, such that the net strain in the REO/Si(1-y)Ge(y) composite layer is effectively reduced over that of a single REO layer of the same net REO thickness grown on the same substrate. In one embodiment rare earth oxide layers are strain balanced such that critical thickness of the REO/Si(1-y)Ge(y) composite is not exceeded. In one embodiment a REO/Si(1-y)Ge(y) composite layer acts to mitigate propagation of dislocations from an underlying REO layer through to the overlying Si(1-z)Ge(z) layer thereby improving the crystallinity and carrier lifetime in the Si(1-z)Ge(z) layer.
FIGS. 16A , B and C illustrate several embodiments; in one embodiment a rare-earth oxide spectral conversion structure, fabricated on, underneath, or within solar cell devices for the purpose of modifying the spectral distribution of the incident radiation. In some embodiments a spectral conversion structure comprises a core layer, optionally, optically active, of (Gd (1-x) Er (x) ) 2 O 3 or other ternary rare-earth compound, in contact with one or more cladding layers of Gd 2 O 3 or other binary rare-earth compound. A cladding layer is designed such that there is substantially no overlap of excited energy levels with those in the core, hence a preference for Gd 2 O 3 over other rare-earth oxides, since it has no energy levels within the solar spectrum. A core layer performs spectral conversion through absorption of light at one or more wavelengths, and emitting light at a different wavelength which is absorbed by a solar cell(s) and converted to electrical energy.
In FIGS. 17A , B and C spectral conversion structures are shown where RE1 is selected such that there is no overlap between energy levels in a cladding and a core material. RE1 and RE2 are selected to give desired optical activity in a core layer.
A key novelty of the instant invention is the isolation of the energy levels in the core by cladding it with a material which contains no overlapping energy levels, thereby preventing resonant energy transfer from a core to quenching sites at the interfaces. This isolation effectively increases the lifetime of the energy levels in the core, thus improving the efficiency of optical wavelength conversion processed in the core layer.
FIG. 18 illustrates a rare-earth oxide spectral conversion structure, fabricated on top of and underneath a solar cell. The top three layers perform a down-conversion or downshifting function, where short wavelength light, for example, less than 500 nm, is converted to longer wavelength light, for example, about 980 nm, which can be efficiently absorbed in the solar cell structure. Again, RE1 and RE2 are selected such that there is no overlap between the energy levels in the cladding and the core material. RE1 and RE2 are also selected to give the desired optical activity in the core layer. Additional up-conversion layers may be fabricated on the back of the solar cell; the three layers closest to the back of the cell have the function of up-converting 1100-1400 nm wavelength light. The next two layers are for up-converting 1400-1800 nm light and the last two are for up-conversion of 1900-2500 nm light. RE3, RE4 and RE5 are chosen to be optically active rare earth species; while RE1 is chosen to form a suitable optically inactive dilutant and passivation layer. In one embodiment RE1 is Gadolinium, RE2 is Terbium, x is 0.1, RE3 is Dysprosium, y is 0.1, RE4 is Erbium, z is 0.1, and RE5 is Dysprosium, w is 0.1. These rare-earths have suitable absorption peaks in each of the wavelength bands of interest. The structure of FIG. 18 may also comprise a reflector structure, not shown, placed behind the last layer so as to reflect the up-converted radiation back through the rare earth layers to a photovoltaic layer, optionally shown as a solar cell.
In some embodiments a structure for converting incident radiation from one wavelength to another comprises a first layer comprising a rare earth compound; and a second layer comprising a semiconductor operable as a photovoltaic cell; such that incident radiation comprising a first wavelength incident on the first layer is converted into one or more wavelengths different than the first wavelength wherein at least a portion of the one or more wavelengths different than the first wavelength are absorbed by the second layer and converted into electrical energy. Optionally, the first layer comprises an initial cladding layer and a secondary cladding layer comprising a compound of composition [RE1] x [J] y and a core layer comprising a compound of composition (RE1 m RE2 n ) o J p positioned between the initial and secondary cladding layers wherein said first layer is positioned between said incident radiation and said second layer such that at least a portion of said incident radiation is down-converted from a higher energy to a lower energy before being absorbed by said second layer. Optionally, RE1 and RE2 are chosen such that there is no overlap between the energy levels in said cladding layers and said core layers and m, n, o, p, x, y>0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof.
Some embodiments comprise a third layer comprising an initial cladding layer and a secondary cladding layer comprising a compound of composition [RE1] e [J] f and a core layer comprising a compound of composition (RE1 a RE3 b ) c J d positioned between the initial and secondary cladding layers wherein the third layer is positioned such that said incident radiation has passed through said second layer into the initial cladding layer such that at least a portion of said incident radiation is up-converted from a lower energy to a higher energy by the third layer; optionally, RE1 and RE3 are chosen such that there is no overlap between the energy levels in said cladding layers and said core layers and a, b, c, d, e, f>0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof.
In some embodiments a distributed Bragg reflector is positioned on said third layer away from said second layer comprising a plurality of sets of first and second layers wherein the first layer is of a composition [RE]x[J]y and the second layer is of composition [Si]m[Ge]n wherein m, x, y>0, and n≧0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof, optionally a reflector layer is placed such that the third layer is between the reflector layer and said second layer.
Some embodiments comprise a fourth layer comprising a secondary cladding layer comprising a compound of composition [RE1] g [J] h and a core layer comprising a compound of composition (RE1 i RE4 j ) k J 1 positioned between the secondary cladding layer and said secondary cladding layer of the third layer wherein g, h, i, j, k, l>0, and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof such that the incident radiation has passed through the third layer such that at least a portion of the incident radiation is up-converted from a lower energy to a higher energy by the fourth layer; optionally, a reflector layer is placed such that the secondary cladding layer of the fourth layer is between the reflector layer and the core layer of the fourth layer.
In some embodiments a structure for converting radiation from one wavelength to another comprises a plurality of layers comprising a semiconductor layer operable as a photovoltaic cell and a rare earth compound layer; and a substrate wherein the first of the plurality of layers comprises a semiconductor layer of composition Si (1-m) Ge m and a rare earth layer of composition [RE1] x [J] y ; the second of the plurality of layers comprises a semiconductor layer of composition Si (1-n) Ge n and a rare earth layer of composition [RE2] u [J] v ; and the plurality of layers is separated from the substrate by a semiconductor layer of composition Si (1-o) Ge o ; wherein u, v, x, y>0, and m, n, o≧0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof; optionally, rare earth layers convert radiation from a low energy to a higher energy.
In some embodiments a structure for converting incident radiation from one wavelength to another comprise a first cladding layer comprising a first rare earth compound; a core layer comprising a second rare earth compound; a second cladding layer comprising the first rare earth compound; and a photovoltaic layer operable to convert at least a portion of the incident radiation to electrical energy comprising a first and second surface; wherein the core layer resides between the first and second cladding layer and the second cladding layer is in contact with the first surface of the photovoltaic layer such that incident radiation passes through the first cladding layer prior to entering the photovoltaic layer such that a portion of the incident radiation is converted from an initial wavelength to a different wavelength by said core layer; optionally the first and second cladding layers comprise a compound of composition [RE1] x [J] y and said core layer comprises a compound of composition (RE1 m RE3 n ) o J p wherein m, n, o, p, x, y>0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof such that there is no overlap between the energy levels in said cladding layers and said core layer; optionally, the composition of said core layer is chosen such that a portion of said incident radiation is up-converted from a longer wavelength to a shorter wavelength.
In some embodiments a structure for converting incident radiation from one wavelength to another comprises a first cladding layer comprising a first rare earth compound; a core layer comprising a second rare earth compound; a second cladding layer comprising the first rare earth compound; and a first and second photovoltaic layer operable to convert at least a portion of the incident radiation to electrical energy each comprising a first and second surface; wherein the core layer resides between the first and second cladding layer and the first cladding layer is in contact with the second surface of the first photovoltaic layer such that incident radiation passes through the first photovoltaic layer prior to entering the first cladding layer and the second cladding layer is in contact with the first surface of the second photovoltaic layer such that incident radiation passes through the core layer prior to entering the second photovoltaic layer such that a portion of the incident radiation is converted from an initial wavelength to a different wavelength by the core layer; optionally, first and second cladding layers comprise a compound of composition [RE1] x [J] y and said core layer comprises a compound of composition (RE1 m RE3 n ) o J p wherein m, n, o, p, x, y>0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof such that there is no overlap between the energy levels in said cladding layers and said core layers; optionally the composition of the core layer is chosen such that a portion of said incident radiation is up-converted from a longer wavelength to a shorter wavelength.
In some embodiments device, comprises a silicon semiconductor based superlattice comprising a plurality of layers that form a plurality of repeating units, wherein at least one of the layers in the repeating unit is an optically active layer with at least one species of rare earth ion wherein the repeating units have two layers comprising a first layer comprising a rare earth compound described by [RE1] x [J] y and a second layer comprising a compound described by Si (1-m) Ge m wherein x, y>0, m≧0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof.
In some embodiments a device, comprises a superlattice that includes a plurality of layers that form a plurality of repeating units, wherein at least one of the layers in the repeating unit is an optically active layer with at least one species of rare earth ion wherein the repeating units comprise two layers wherein the first layer comprises a rare earth compound described by [RE1] x [J] y and the second layer comprises a compound described by ((RE2 m RE3 n ) o J p wherein m, n, o, p, x, y>0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof; optionally, RE1, RE2 and RE3 may refer to different rare earths in different repeating units as suggested in FIG. 18 .
In some embodiments a structure for converting incident radiation from one wavelength to another comprises a first layer comprising a semiconductor operable as a photovoltaic cell; and a second layer comprising a rare earth compound; such that incident radiation comprising a first wavelength is incident on the first layer and the first wavelength is substantially transmitted through the first layer to the second layer and is converted therein into one or more wavelengths different than the first wavelength; optionally, the second layer comprises an initial cladding layer and a secondary cladding layer comprising a compound of composition [RE1] x [J] y and a core layer comprising a compound of composition (RE1 m RE2 n ) o J p positioned between the initial and secondary cladding layers wherein said second layer is positioned behind said first layer such that at least a portion of said incident radiation passes through said first layer before entering said second layer; optionally, RE1 and RE2 are chosen such that there is no overlap between the energy levels in said cladding layers and said core layers and m, n, o, p, x, y>0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof.
In some embodiments a third layer comprises a secondary core layer comprising a compound of composition (RE1 u RE3 v ) w J z positioned between said secondary cladding layer and a tertiary cladding layer comprising a compound of composition [RE1] k [J] l wherein the third layer is positioned such that said incident radiation has passed through said second layer into the third layer such that at least a portion of said incident radiation is up-converted from a lower energy to a higher energy by the secondary core layer; optionally, RE1 and RE3 are chosen such that there is no overlap between the energy levels in said cladding layers and said core layers and u, v, w, z, k, l>0 and J is chosen from a group comprising oxygen, nitrogen, phosphorous and combinations thereof; optionally a reflector layer is placed such that the tertiary cladding layer of said third layer is between the reflector layer and said secondary core layer of said third layer.
As known to one knowledgeable in the art, a photovoltaic device may be constructed from a range of semiconductors including ones from Group IV materials, Group III-V materials and Group II-VI; additionally, photovoltaic devices such as a laser, LED and OLED may make advantageous use of the instant invention for up and/or down converting emitted light.
The foregoing described embodiments of the invention are provided as illustrations and descriptions. They are not intended to limit the invention to a precise form as described. In particular, it is contemplated that functional implementation of invention described herein may be implemented equivalently in hardware and/or various combinations of hardware and software and/or other available functional components or building blocks. Other variations and embodiments are possible in light of above teachings to one knowledgeable in the art, and it is thus intended that the scope of invention not be limited by this Detailed Description, but rather by Claims following. All patents, patent applications, and other documents referenced herein are incorporated by reference in their entirety for all purposes, unless otherwise indicated.
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The use of rare-earth (REO, N, P) based materials to covert long wavelength photons to shorter wavelength photons that can be absorbed in a photovoltaic device (up-conversion) and (REO, N, P) materials which can absorb a short wavelength photon and re-emit one (downshifting) or more longer wavelength photons is disclosed. The wide spectral range of sunlight overlaps with a multitude of energy transitions in rare-earth materials, thus offering multiple up-conversion pathways. The refractive index contrast of rare-earth materials with silicon enables a DBR with >90% peak reflectivity and a stop band greater than 150 nm.
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CROSS REFERENCE TO RELATES APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/701,580, filed Dec. 11, 2000, which is a national stage filing under 35 U.S.C. 371 of PCT/EP99/03686 filed May 28, 1999 designating the United States and Published by the International Bureau in a language other than English on Dec. 16, 1999.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a device for securing a weaving reed, hereafter reed, to the batten beam of a weaving machine, the reed comprising an upper profiled bar, in particular an upper U-channel, a lower profiled bar, in particular a lower U-channel, to be secured to the batten beam, and reed dents mounted in-between the channels.
[0004] 2. Description of the Related Art
[0005] It is known to affix the lower U-channel profiled bar of a reed by a clamp, for instance by a key, to a batten beam. However it has been observed that at high weaving rates, i.e. of the order of 1,000 or more filling insertions per minute, that the reed dents may break in the vicinity of the lower U-channel profiled bar.
[0006] It is known to reinforce one or both ends of the reed with solid steel bars which are mounted between the upper and lower U-channels in relation to the reed dents and parallel to them. Such a reinforcing bar may be straight or be bent several times. When such a reinforcing bar is situated on the filling insertion side of the reed, difficulties are encountered in locating the main air jet nozzles and a cutter for the fillings, which should be located directly at the fabric selvage or at the reed. If such a reinforcing bar is mounted on the opposite reed side, then it will hamper the installation of a filling detector or of a filling stretcher, which also should be mounted directly at the fabric's side selvage or at the reed. In many cases this leads to a fabric having relatively wide waste edges. Moreover there may be streaks at the fabric edge in the zone of a solid-steel reinforcing bar. Regardless, at high weaving rates, such a reinforcing bar may fail to prevent the reed dents from breaking at the lower U-channel.
SUMMARY OF THE INVENTION
[0007] The objective of the invention is to create a device of the initially cited kind to substantially reduce the danger of the reed dents breaking.
[0008] This problem is solved in that the upper profiled bar of the reed is secured, at least in its end region, to the batten beam by a connecting brace element running substantially in the reed's longitudinal direction, against displacements in said longitudinal direction relative to the beam.
[0009] The invention offers the feature that the reed, in particular the upper profiled bar, and the reed dents shall not oscillate in the longitudinal direction of the reed. As a result the danger of reed dent rupture in the vicinity of the lower profiled bar already is substantially reduced.
[0010] In a further embodiment of the invention, the connection element shall be flexible transversely of the reed. Consequently the connection brace element will not restrict the reed dent deformation transversely to the reed's longitudinal direction at beat up against the fabric's edge, and thereby the reed dents are able to deform uniformly at beatup. This feature generally precludes fabric streaks. Also the danger of reed dent rupture in the vicinity of the lower profiled bar caused by beatup stresses is substantially reduced.
[0011] In a preferred embodiment, the connecting brace element is a metal blade affixed both to the upper profiled bar of the reed and at a distance from the end of the reed to the batten beam. In an advantageous design, the blade is made of steel and its thickness transversely to the reed is about 2 mm, its height parallel to the reed is about 15 mm and its length is approximately 100 to 200 mm. Such a blade will not bend at the stresses encountered, and longitudinal reed displacements are substantially prevented. Transverse displacements however are allowed and as a result the danger of forming streaks in the fabric is reduced.
[0012] In a further embodiment of the invention, a support holding the connecting element brace is mounted on the batten beam in a direction along an extension of the reed. As a result the connecting element is connected in simple manner to the batten beam while spaced from the reed. As regards an airjet loom, at least one main jet nozzle shall be mounted appropriately on this support. When the connecting element is mounted opposite the insertion side, then appropriately a filling detector and/or a filling stretcher shall be mounted on the said support. As a result, this support also can be used to mount operationally required components and the total number of additional parts is very low.
[0013] The invention also contemplates a method for bracing a reed against longitudinal movement at its upper end.
[0014] Further features and advantages of the invention will be evident from the description of the embodiments shown in the drawing and in the sub-claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a perspective of a device of the invention to affix a reed to a batten beam,
[0016] [0016]FIG. 2 is a section along the plane II of FIG. 1,
[0017] [0017]FIG. 3 is a section along plane III of FIG. 1,
[0018] [0018]FIG. 4 is a section along plane IV of FIG. 1, and
[0019] [0019]FIG. 5 is a perspective of another embodiment of a device of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The reed 1 shown in FIGS. 1 and 2 is fitted with a plurality of sequentially mounted reed dents 2 . A U-shaped recess is present approximately centrally in the reed dents 2 which together constitute a guide duct 3 for a filling. The reed dents 2 are affixed in a cross-sectionally profiled upper and a lower bar, namely in an upper U-channel 4 and in a lower U-channel 5 . In both the upper U-channel 4 and in the lower U-channel 5 , the reed dents 2 are kept apart from each other a predetermined distance by so-called connecting spirals 7 , 8 . Together with one connecting spiral 7 and 8 and retention bars 9 and 10 , the reed dents 2 are bonded into the upper and lower U-channels 4 and 5 respectively. The lower U-channel 5 is affixed by a key 11 and screws 13 to a batten beam 12 . The batten beam 12 is affixed in known manner by batten arms (not shown) to a batten shaft (not shown) extending parallel to the batten beam 12 .
[0021] In addition, an elongated connecting blade or brace element 14 is mounted on the reed 1 and extends substantially in the longitudinal direction A of this reed 1 and because it is longitudinally inextensible and resists bending under longitudinal compression it prevents said reed from moving in said direction A relative to beam 12 . In this embodiment the connecting blade 14 is mounted on the filling insertion side of the reed 1 . The connecting blade 14 is made of steel for instance and its thickness in the transverse direction B is roughly 2 mm. Its height is about 15 mm. The connecting blade's length is about 100 to 200 mm.
[0022] The end 15 of the connecting blade 14 is connected to the batten beam 12 and is spaced from the reed 1 . A fastener 17 is mounted on the end 15 and is affixed by a screw 16 to a support 18 which in turn is affixed to the batten beam 12 . This connection is carried out in relation to the connection of the lower U-channel 5 , that is using a key 19 and screws 20 , as shown in FIGS. 1 and 3.
[0023] The support 18 is formed in the shape of a bent metal plate which, in the case of an airjet loom, and as shown in FIGS. 1 and 3, also supports one or more main jet nozzles 21 , 22 . For that purpose a retention device 23 of the main airjet nozzles 21 , 22 is fastened by screws 24 to the support 18 . The ends of the jet tubes 25 , 26 of the main airjet nozzles 21 , 22 are also fastened by a further retention element or means 27 and a screw 28 to the support 18 .
[0024] The end 29 of the connection blade 14 which is directed to the reed 1 is mounted to the upper U-channel 4 of said reed. For that purpose a strip 30 is inserted into that space between the section of the legs of the U-channel which overhang and extend beyond the reed dents 2 . The width of this strip 30 is about the same as the width of the upper zones of the dents 2 of the reed 1 which are bonded into the zone subtended between the legs of the upper U-channel 4 . Accordingly the strip 30 can be housed in said leg space of the upper U-channel 4 similar to the reed dents 2 . The strip 30 adjoins the first dent 2 A of the reed 1 and the end of the connecting spiral 7 . The retention bars 9 run over a given length beyond the first reed dent 2 A and the end of the connecting spiral 7 . Together with the retention bars 9 , the strip 30 is bonded to the upper U-channel 4 . Moreover the retention bars 9 may be welded onto the strip 30 . A strong connection is required between the strip 30 and the upper U-channel 4 because it must absorb comparatively high stresses. The shown embodiment also includes a retention strip 32 which is bonded to the back side of the upper U-channel 4 of the reed 1 . The connecting blade 14 is mounted between the strip 30 and the retention strip 32 and is affixed by a screw connector 31 that extends through suitable aligned connector receiving feature or apertures in blade 14 and strips 30 , 32 (see FIG. 4). Preferably the strip 30 is made of steel because such a selection is advantageous when affixing the connecting blade 14 using a screw 31 . The thickness of the connecting blade 14 of this embodiment substantially corresponds to the thickness of the rear leg 33 (FIG. 2) of the upper U-channel 4 . In this case, after the screw 31 has been tightened, the strip 30 and the retention strip 32 remain substantially mutually parallel. This design is especially appropriate for reeds wherein the upper U-channel 4 is made of aluminum or another relatively lightweight metal which per se would offer only modest mechanical strength.
[0025] In one embodiment variation, the connecting blade 14 is directly affixed by a screw to the upper U-channel 4 of the reed 1 . This design is advantageous for instance when the upper U-channel 4 of the reed 1 is made of steel or another metal of comparatively high mechanical strength.
[0026] [0026]FIG. 5 shows an embodiment which again offers the above described advantages, but wherein a connecting blade 34 is mounted on the opposite side of the reed 1 , that is, at the side which is opposite the filling insertion side. The connecting blade 34 is connected in the manner of the embodiment of FIG. 1 by one end 39 to the upper U-channel 4 of the reed 1 and by its end 40 to a support 35 . A filling detector 36 and/or a filling stretcher 37 is/are mounted on the support 35 which again is a bent metal plate and therefore are mounted directly next to the reed 1 . The filling detector 36 and the stretcher 37 each are affixed by a screw 41 and 42 to the support 35 .
[0027] In a further embodiment not shown, a connecting blade 14 is mounted at the filling insertion side of the reed 1 corresponding to FIG. 1 as well as a connecting blade 34 at the opposite side corresponding to FIG. 5.
[0028] By introducing one or both elongated connecting blades 14 , 34 , the reed 1 and in particular the upper U-channel 4 and the reed dents 2 shall be prevented from oscillating in the longitudinal direction A during weaving operation. The connecting blades 14 and/or 34 absorb both tensile and compressive forces, which prevent a displacement of the upper U-channel 4 toward the filling insertion side and in the opposite direction. The connecting blades 14 and 34 are dimensioned in such manner that they shall be strong enough not to bend when subjected to compression. Calculation shows that a connecting blade 14 or 34 about 2 mm thick and about 15 mm high is adequately resistant to bending when forces that arise at a weaving rate of 1,200 filling insertions a minute and with as many corresponding beatups.
[0029] The elongated connecting blades 14 and/or 34 at worst will slightly degrade the displacement in the transverse direction B of the end zone 6 of the reed 1 in the vicinity of the main airjet nozzles 21 , 22 and/or of the end zone 38 of the reed 1 in the vicinity of the filling detector 36 or the stretcher 37 . The displaceability of the reed 1 in these zones 6 and 38 is not restricted with respect to the middle zone. Such a feature is attained by the connecting blades 14 and/or 34 being comparatively long and consequently will not unduly oppose bending in the transverse direction B. As a result, any differential in the displaceability of the reed 1 in the transverse direction B is prevented that produces streaks or other irregularities in the vicinity of the selvages. On the other hand, because displacements and oscillations of the upper U-channel 4 are substantially suppressed in the longitudinal direction A, the dents 2 of the reed 1 are stressed less in the vicinity of the lower U-channel 5 , and consequently the danger that the reed dents 2 should break in this region is considerably reduced.
[0030] The elongated connecting blade or brace elements 14 or 34 need not necessarily be in the shape of a blade or the like. Illustratively they may be in the form of round or polygonal bars of arbitrary cross-sections, which however should be designed in such a way that while substantially suppressing a displacement of the reed in the longitudinal direction A, they shall allow the displacement of the reed 1 in the transverse direction B. If called for, the connecting elements also may be wires, especially steel wires, or also plastic cords.
[0031] The invention is not restricted to the above described and illustrated embodiments. The scope of the invention is defined by the attached claims and allows changes and/or other combinations.
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A loom reed including upper and lower bars which support reed dents and extend along the length of the reed is provided with a connecting device for connecting a brace to the upper bar to restrict longitudinal movement of the reed during loom operation. A method of bracing a reed against longitudinal movement is disclosed.
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THE FIELD OF THE INVENTION AND PRIOR ART
[0001] The present invention relates to a component designed for use in a light water reactor and at least partly comprised by a metal and/or a metal alloy with at least one surface that presents a coating, and a method of creating a coating resistant to hydration on at least one surface of a component which is designed for use in a light water reactor and which is partly comprised by a metal and/or metal alloy by subjecting the component to a treatment with a gas mixture while heating.
[0002] Components in nuclear plants are often subjected to attacks caused by hydration, oxidation and/or wear, and it is often necessary to deposit a coating onto the surface of the components in order to protect the latter. Cladding tubes for nuclear fuel form an example of such components. In the worst scenario, attacks on a cladding tube for nuclear fuel result in a damage extending through the total thickness of the cladding tube in such a way that the radioactive nuclear fuel inside the cladding tube leaks out to the surrounding. This may be caused by primary as well as secondary damages on the cladding tube.
[0003] Primary damages are created by attacks on the outer surface of the cladding tube, said attacks being caused by oxidation, due to the contact between the cladding tube and the cooling water, or due to wear. A primary damage extending through the total thickness of the cladding tube implies that water, water steam or a combination thereof flows through the damage, so that a space between the fuel and the inner surface of the cladding tube is filled by the water, water steam or the combination thereof. The presence of the water, water steam or the combination thereof in this space implies that the cladding tube runs the risk of being damaged by attacks from inside the tube. This attack often takes place through hydration. Such a damage is called a secondary damage and can only occur when a primary damage already has occurred. Secondary damages extending through the total thickness of the cladding tube result in a leakage of the nuclear fuel inside the cladding tube, and thereby of radioactivity, to the surrounding. Secondary damages can occur at relatively long distances from the primary damage and, therefore, often have the shape of long cracks, which make them a serious type of damage.
[0004] A lot of work has been done to develop a coating on such a cladding tube in order to make the coating more resistant to hydration, oxidation and/or wear and thereby able to prevent damages at the cladding tube. Particularly, it has been difficult to produce coatings at the inside of the cladding tube, said coatings resulting in a good protection against secondary damages. There, a coating which is particularly resistant to hydration is required.
[0005] In order to test the resistance to hydration and oxidation of a coating on a cladding tube a method is normally used where the cladding tube is autoclaved by conditions similar to the ones that the cladding tube is subjected to during use thereof in a nuclear plant, whereafter the presence of hydration and oxidation respectively by the coating and the cladding tube is examined. The autoclaving of the cladding tube by this method is not to be confused with an autoclaving that may be used for creating protective coatings on cladding tubes. The latter type of autoclaving will be described more in detail later in this text.
[0006] Until the seventies contents of hydrogen in the shape of water in uranium dioxide in fuel pellets resulted in the cladding tube being subjected to hydration at its inside. These damages are called blisters and differ from secondary damages, even though both of them are caused by hydration at the inside of cladding tubes. These days, the uranium is substantially free from hydrogen, and thereby, the problem with blisters has disappeared.
[0007] During the sixties and seventies a coating was produced in a cladding tube for nuclear fuel by autoclaving the cladding tube in substantially saturated water steam at a temperature of approximately 425° C. and at a pressure of from 0.1 to 0.5 MPa for 24 hours. The result thereby was a coating comprised by zirconium dioxide (ZrO 2 ), which normally had at thickness of from 0.5 to 1 μm. This coating had a relatively low resistance against hydration and therefore it had no substantially protective effect with regard to secondary damages on the cladding tube.
[0008] The patent document DE-A-2 429 447 discloses a cladding tube made of zirconium or niobium alloy with a coating comprised by an oxide layer arranged at an inner surface as well as an outer surface of the cladding tube.
[0009] During the eighties a liner layer preferably made of zirconium was applied to the inside of the cladding tube for protection against stress corrosion caused by iodine formed in the uranium dioxide during the fission.
[0010] In the patent document JP-A-63 179 286 a liner layer of zirconium on an inner surface of a cladding tube made of zirconium alloy is combined with a subsequent autoclaving which produces a coating of zirconium dioxide on the outer surface of the cladding tube and on the surface of the liner layer. The autoclaving was performed at a pressure of 5 MPa and at a temperature of at least 400° C. The difference between the autoclaving according to this patent document and the autoclaving according to the method used in the sixties and the seventies described herein is that the autoclaving according to the Japanese patent document takes place in presence of at most 10% water steam, while the autoclaving according to the technique of the sixties and seventies was performed in the presence of generally 100% water steam. However, in the patent document there is only one example of embodiments with autoclaving in a dry atmosphere. A coating on the liner layer on the inner surface of the cladding tube had a thickness of least 0.2 μm and preferably 0.5 to 1.0 μm.
[0011] The inventors have experienced that the coating according to JP-A-63 179 286, in comparison with a coating produced by means of autoclaving in the presence of substantially 100% water steam according to the above technique from the sixties and seventies, results in an improved protection against H 2 -absorption, but that it does not provide a sufficient barrier against H 2 -permeation to prevent secondary damages on the cladding tube.
[0012] By methods of producing a coating on a surface, where the methods are performed by autoclaving the component under pressure, the reaction speed between active constituents in the gas and the material in the surface of the component is regulated by, amongst others, varying the pressure. This is a very bad way of regulating the reaction speed, and relatively small pressure variations during the course of the treatment may cause large variations with regard to the reaction speed, which in its turn might lead to the appearance of defects in the coating. Autoclaving according to prior art is therefore performed at a constant pressure, that is at static conditions.
[0013] By a production of a cladding tube designed for use in a light water reactor a series of annealings of the uncoated cladding tube is performed in order to provide good mechanical properties to the latter. By employment of methods according to prior art the cladding tube is then moved to a special final annealing plant which permits treatment under pressure action, for execution of a final annealing and, thereby, a production of a coating. Of economical reasons it is not acceptable to execute the annealings of the cladding tube for obtaining good mechanical properties in a plant which makes pressure treatment possible, as these annealings do not require the use of pressure. Therefore, the final annealing, and thereby the production of the coating, constitutes one step in the total treatment of the cladding tube, said step being separated from previous treatment steps.
[0014] Accordingly, prior art does not offer any coating at the inside of a cladding tube for fuel in a light water reactor, said coating providing an effective protection against H 2 -permeation, such that secondary damages may be prevented. Moreover, by methods of prior art, the reaction speed is controlled in an unsatisfying way. Furthermore, prior art requires the use of a particular plant that permits pressure treatment.
SUMMARY OF THE INVENTION
[0015] The object of the present invention is to remedy the above problems, and more precisely to provide a component which is designed for use in a light water reactor and which has surfaces with a coating that reduces the risk for damages on the component, particularly the risk for secondary damages, and a method of producing such a component.
[0016] This object is obtained by means of the initially defined component which is characterized in that the coating comprises at least one of a nitride and an oxide compound, and that the coating has such a thickness that hydration of the component is substantially prevented. The ability of the coating to protect the underlying component against hydration depends upon the resistance of the coating against hydration and of how well it covers the surface of the underlying component. The resistance of the coating against hydration is, in its turn, depending on the structure, the composition and the thickness of the coating. Nitride and oxide compounds fulfil these requirements and, therefore, they are usable as a material of the coating, provided that it is of a sufficient thickness to be resistant against hydration.
[0017] According to one embodiment of the invention the coating has a thickness of at least 1 μm and at most 25 μm. Within this thickness range a coating which has a good resistance against hydration is obtained. By coatings with a thickness smaller than 1 μm an inferior resistance against hydration is obtained, and by coatings with a thickness larger than 25 μm the risk of scaling of the coating from the surface of the component is significant. As scaling implies that significant defects occur in the coating and that the surface of the component becomes unprotected at these defects it is very important to avoid a coating that runs the risk of scaling. According to one application of the embodiment, the coating has a thickness of at least 3 μm. A thickness of 3 μm implies that the coating has a better resistance against hydration in comparison with a coating with a thickness of 1 μm.
[0018] According to another embodiment of the invention the component comprises an inner space, and the coating is deposited onto at least one surface in the inner space of the component. Several components in light water reactors, for example tubes, comprise an inner space, and it is often required to protect the surface of this inner space.
[0019] According to another embodiment of the invention at least one of the surfaces of the component is comprised by zirconium or a zirconium alloy and the coating comprises at least one of zirconium dioxide (ZrO 2 ) and zirconium nitride (ZrN). Several components in light water reactors are made of zirconium or a zirconium alloy as these materials have properties suitable for the purpose. However, the materials have a too insignificant resistance to hydration, oxidation, corrosion or wear to be used as uncoated in light water reactors. Therefore, a coating presenting good such properties is often provided on the surface of the component.
[0020] According to another embodiment of the invention, the coating has such properties that oxidation of the component is generally prevented. Such a coating accordingly constitutes a protection against hydration as well as oxidation of the component, which is desirable as the component often is subjected to attacks by hydration as well as oxidation.
[0021] According to another embodiment of the invention the coating has such properties that a wear of the component is substantially prevented. This is desirable as the component is often subjected to a combination of hydration and wear or hydration, oxidation and wear.
[0022] According to another embodiment of the invention the component is a cladding tube for nuclear fuel. According to one application of the embodiment the cladding tube presents a liner layer on the surface of the inner space, and the coating is located upon this-liner layer.
[0023] According to another embodiment of the invention, the coating on the cladding tube has such a high resistance against hydration that the risk of having secondary damages on the cladding tube is substantially eliminated.
[0024] The provision of the coating defined above is obtained by means of the initially defined method which is characterized in that the treatment is performed at a substantially atmospheric pressure and that the gas mixture comprises water steam and at least one of oxygen, nitrogen, an active gas containing oxygen and an active gas containing nitrogen. It is a significant advantage that the treatment may be performed at atmospheric pressure and, thus, do not require an equipment for providing a pressure treatment. Therefore, the treatment at atmospheric pressure implies a saving of both time and money.
[0025] According to one embodiment of the method of the invention the coating is produced by making at least one of oxygen, nitrogen, an active gas containing oxygen and an active gas containing nitrogen react with at least one material located in the surface of the component. According to one application of the embodiment the coating is comprised by at least one of an oxide or a nitride of at least one material located in the surface of the component. Such oxides and nitrides normally have a good resistance against hydration, oxidation and wear and the coating therefore provides a good protection for the component against this.
[0026] According to another embodiment of the method of the invention the treatment is controlled by adding one or more inert gases suitable in this context. These gases dilute the active gases in such a way that favourable reaction conditions are obtained. The addition of the inert gas or gases results in a reduced reaction speed between the gas and the surface material. If the reaction speed is too high the obtained coating will be full of defects and will not therefore constitute a good protection for the component. If, on the other hand, the reaction speed is too low a coating generally free from defects is obtained, but it takes a lot of time to produce this coating. By controlling the reaction speed at a suitable level it is possible to obtain a coating generally free from defects within a reasonable period of time This embodiment of the method of the invention provides an effective way of precisely regulating the reaction speed between active constituents in the gas and the surface of the component. By the method according to this embodiment of the present invention it is possible to vary the addition of the inert gas or gases during the time of the treatment, thereby varying the reaction speed. By the method according to the present invention the treatment is thus performed under dynamic conditions, as a difference to autoclaving according to prior art which, as described earlier, is performed under static conditions. According to one application of the method according to this embodiment the inert gases advantageously comprise at least one of the noble gases argon, helium and neon.
[0027] According to another embodiment of the method of the invention the treatment is controlled by varying the amount of water steam in the gas mixture. Different surface materials require different amounts of water steam in the gas mixture in order to produce a coating on the component, through a reaction between active constituents in the gas mixture and in the material of the surface of the component, said coating being sufficiently thick for its purpose. According to one application of the embodiment the gas mixture comprises at least 10% water steam. The inventors have experienced that this a minimum level of water steam required to accomplish coatings with suitable properties.
[0028] According to another embodiment of the invention the treatment is performed at such a temperature that an oxidation and a nitration respectively takes place, preferably at a temperature of at least 450° C. and at most 650° C.
[0029] According to one application of the method of the invention the gas mixture contains air. Air contains both oxygen and nitrogen in an easily accessible state and is also a cheap alternative which is perfect to use by the method of the invention.
[0030] According to another application of the method of the invention the gas mixture is free from nitrogen or active nitrogen compounds. This implies that the created coating definitely is comprised by oxides free from contaminations of nitrides or other nitrogen compounds.
[0031] According to another application of the method of the invention the gas mixture comprises carbon dioxide (CO 2 ). According to another application of the embodiment the gas mixture comprises a mixture of carbon monoxide (CO) and carbon dioxide (CO 2 ). These mixtures are added in order to control the oxidation potential.
[0032] According to another application of the method of the invention the gas mixture comprises dinitrogen oxide (N 2 O). Also oxygen and argon may exist together with the dinitrogen oxide in the mixture.
[0033] According to one application of the method of the invention the treatment is performed for a period of time of 1 to 10 hours.
[0034] According to one application of the method of the invention the surface or the surfaces of the component treated comprise zirconium or a zirconium alloy.
[0035] According to another application of the method of the invention the coating produced on the surface or surfaces of the component by the treatment comprises at least one of zirconium dioxide (ZrO 2 ) and zirconium nitride (ZrN).
[0036] According to another application of the method of invention the treatment is performed by depositing the coating on at least one of a surface of an inner space and the outer surface of the component.
[0037] According to another application of the method of the invention the component treated is a cladding tube for nuclear fuel.
[0038] According to another application of the method of the invention the cladding tube is annealed a plurality of times in order to provide mechanical strength, and the treatment mentioned earlier represents a final annealing executed in the same plant as these annealings During use of the method of the invention no move of the cladding tube to a special final annealing plant is thus required, as the final annealing, and thereby the production of the coating, is performed at atmospheric pressure. The final annealing may therefore be accomplished in the plant where the annealing to obtain a good mechanical strength is performed, and thereby provide an integrated part of the total annealing. The production of the coating accomplished in accordance with the method of the invention thus saves both time and money, compared with if the method according to prior art had been employed instead.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The present invention will now be described more in detail with reference to the embodiments shown on the attached drawings.
[0040] [0040]FIG. 1 shows a schematic sectional view of a part of a cladding tube comprising surfaces which present a coating according to the invention.
[0041] [0041]FIG. 2 shows a schematic sectional view of a part of a cladding tube comprising surfaces that are uncoated.
DETAILED DESCRIPTION OF EMBODIMENTS
[0042] In FIG. 1 a part of a cladding tube 1 is shown, said tube being arranged in a light water reactor and nuclear fuel being provided therein as fuel pellets 2 . On its outer surface 3 the cladding tube 1 presents a coating 4 according to the invention. The cladding tube 1 also presents a liner layer 6 on its inner surface 5 , on which layer a coating 7 according to the invention is provided. The coating 7 may be deposited by means of CVD-technique. By use in a light water reactor the coating 4 on the outer surface 3 of the cladding tube 1 is in contact with a primary cooling circuit that comprises water, water steam or a combination thereof. The coating 4 on the outer surface 3 of the cladding tube 1 has as its task to protect the outer surface 3 of the cladding tube against attacks, preferably caused by oxidation, due to the presence of the water, water steam or the combination thereof, or wear due to the contact with other components in the light water reactor. The coating 4 thus presents a good resistance against oxidation and wear. If, despite this, the coating 4 will get a damage extending through the total thickness of the coating 4 , an area of the outer surface 3 of the cladding tube 1 will be exposed to the water, water steam or the combination thereof, whereby this area will oxidate until a damage extending through the total thickness of the cladding tube 1 finally will be created. If the oxidation continues a damage extending through the total thickness of the liner layer 6 will finally be created. Thereby a damage extending through the total thickness of the coating 4 , the cladding tube 1 , the liner layer 6 and the coating 7 , a so called primary damage, is formed. In such cases the water, water steam or the combination thereof will penetrate through the primary damage to an inner space 8 between the coating 7 and the fuel pellets 2 . Thereby, the water, water steam or the combination thereof will fill the inner space 8 and attack the coating 7 . These attacks may occur at long distances from the primary damage and be caused by hydration. Thanks to the coating 7 of the invention having a high resistance against hydration mostly no damages extending through the total thickness of the coating 7 are formed. The coating 7 and the combination of the coating 7 and the liner layer 6 thereby significantly reduces the risk of secondary damages being formed on the cladding tube 1 in comparison with uncoated cladding tubes. It also possible to exclude the liner layer 6 and still obtain a good protection against hydration at the inner surface 5 of the cladding tube 1 .
[0043] In FIG. 2 a part of a cladding tube 1 according to prior art is shown, said tube being arranged in a light water reactor and nuclear fuel being arranged therein as fuel pellets. By use in a light water reactor an outer surface 3 of the cladding tube 1 is in contact with a primary cooling circuit comprising water, water steam or a combination thereof. Water, water steam or a combination thereof has an oxidating effect on the outer surface 3 of the cladding tube 1 . The outer surface 3 of the cladding tube 1 is also subjected to wear from other components present in the light water reactor. The material of the cladding tube 1 has not a sufficient resistance against wear and oxidation to prevent the creation of damages by these attacks. When such a damage is well initiated on the outer surface 3 of the cladding tube 1 , through the action of oxidation or wear, the oxidation progresses at the location of this damage. Finally, the result thereof is a damage extending through the total thickness of the cladding tube 1 . By such a primary damage the nuclear fuel in the fuel pellets 2 may leak through the damage to the primary cooling circuit and thus spread radioactivity to said circuit. The damage extending through the total thickness of the cladding tube 1 also implies that the water, water steam or the combination thereof from the primary cooling circuit penetrates through the damage into the cladding tube to an inner space 4 located between the fuel pellets 2 and an inner surface 5 of the cladding tube 1 . The water, water steam or the combination thereof is spread in the inner space 4 and has a hydrating effect on the inner surface 5 of the cladding tube 1 . The material of the cladding tube 1 has not a sufficient resistance against this hydration, and damages will therefore be created on the inner surface 5 of the cladding tube 1 . These damages may occur at long distances from the primary damage due to the fact that the water, water steam or the combination thereof causing the damage is spread over so large areas in the inner space 4 . The damage created on the inner surface 5 of the cladding tube 1 then grows until, finally, a damage extending through the total thickness of the cladding tube is formed. The nuclear fuel from the fuel pellets 2 may leak out through such secondary damages and further spread radioactivity to the primary cooling circuit.
EXAMPLE 1
[0044] An uncoated cladding tube for nuclear fuel with a liner layer provided on an inner surface of the cladding tube was subjected to a final annealing in order to produce a coating according to the invention on an inner surface onto the liner layer as well as an outer surface of the cladding tube. This final annealing was performed at atmospheric pressure by treating the cladding tube for 90 minutes at a temperature of 565° C. under the action of a gas mixture comprising oxygen, argon and water steam. This treatment resulted in a coating of zirconium dioxide (ZrO 2 ) on an inner surface on the liner layer as well as on an outer surface of the cladding tube. This coating presented a good resistance against hydration, oxidation and wear.
EXAMPLE 2
[0045] The final annealing was executed in the same way as in example 1 with the only exception that the gas mixture contained nitrogen instead of oxygen. The result thereof was a coating comprised by zirconium nitride (ZrN) on an inner surface, upon the liner layer, and on an outer surface of the cladding tube. This coating had a good resistance against hydration, oxidation and wear.
[0046] The thickness of the coating according to the invention may vary from at least 1 μm or at least 3 μm to at most 10 μm or at most 25 μm in order to obtain a good resistance against hydration, oxidation and wear.
[0047] Generally, the method comprises the provision of a coating of zirconium oxide or zirconium nitride on the inside of a cladding tube by subjecting said tube to an environment that comprises a controlled gas mixture that comprises metal organic compounds and also one or more other gases, such as oxygen gas, carbon dioxide, methane and/or nitrogen gas. By controlling the temperature, reaction amounts, pressure and gas content of said environment, an even coating which is very dense and resistant to hydration may be provided. The thickness thereof is preferably between 1 and 10 μm.
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A component ( 1 ) designed for use in a light water reactor and at least partly comprised by a metal and/or a metal alloy presents a coatings ( 4, 7 ) at its outer surface ( 3 ) and its inner surface ( 5 ). The coating ( 4 and 7 respectively) has as its task to protect the surface ( 3 and 5 respectively) against oxidation, corrosion, wear and hydration. The coating ( 4 and 7 respectively) suitably comprises at least one of zirconium dioxide (ZrO 2 ) and zirconium nitride (ZrN).
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BACKGROUND OF THE INVENTION
The present invention relates to steel elements which can be used for reinforcing vulcanized elastomeric articles based on natural or synthetic rubber, such as tires, belts, hoses, straps and like products.
More particularly, it relates to rubber adherable steel elements for reinforcing rubber articles which are vulcanizable with sulphur, such as e.g. vehicle tires. These reinforcing elements are generally covered with a brass coating, thereby providing better adhesion to the rubber.
The term steel reinforcing elements as used herein is intended to be generic to all steel products suitable for strengthening rubber articles, including wires, filaments, strands, cables, tire cords, steel plates, shaped wire products and combinations thereof without being limited thereto.
The term steel refers to what is commonly known as high carbon steel, i.e. iron-carbon alloys containing from 0.4 to 1.4% carbon, usually from 0.6 to 1% C, and which may contain additional alloying elements in varying amounts.
The term brass refers to an alloy substantially of copper and zinc, the composition of which can also include other metals in varying lesser amounts. The copper content of a rubber adherable brass composition can range from 50 to 99% by weight, but in the majority of cases, such as e.g. in bonding steel cord to rubber components for tires, a copper content ranging from 55 to 75% is now regarded as being most suitable by those skilled in the art.
Hence, the wide-spread practice of vulcanization of rubber onto a brass plated metal substrate is now extensively applied in manufacturing steel reinforced rubber articles, and in particular the use of brassed steel cord for tire materials is well known.
Steel cord for use in tire applications is normally made by twisting or cabling together brassplated high-carbon steel wires, drawn to a filament diameter of from about 0.10 to 0.50 mm. The brass alloy coating usually comprises 60 to 75% Cu and 40 to 25% Zn; the plating thickness may range from 0.05 to 0.50 μm, preferably from 0.10 to 0.35 μm. In practice, the specific composition and thickness of the brass alloy coating on the wire are restricted by the adhesion requirements for a given rubber compound and by wire manufacturing considerations. Hence, brass composition and plating thickness are optimized in each case to obtain maximum "initial" adhesion (i.e. just after vulcanization) and to afford good wire drawability, given the large deformation and friction imposed on the coating during the final wire manufacturing steps. For this purpose it is advisable to have a brass alloy with homogeneous α-structure, i.e. a composition which is substantially free of the β-phase (a hard and less deformable crystal type) which gradually appears below 62-63 % Cu, and even from below 65% Cu in less homogeneous Cu-Zn alloy deposits.
At present, the dual requirement of securing an adequate initial rubber to steel adhesion and of facilitating the drawing of the wire is reasonably well solved by known brass coatings and forms part of the state of the art. However, maintaining a sufficiently high post-cured adhesion level during the service life of the rubber article, e.g. during the running life of the tire, is still a major problem in the industry. It has been observed that moisture is generally very detrimental to the adhesion between the brass plated steel reinforcing element and the rubber article. Variation of water content in the unvulcanized rubber compound, for instance, is already known to be a problem. Of even greater importance is the effect of humidity (water pick-up) and heat after curing on degradation of the adhesive bond, especially during the service life of the steel cord reinforced rubber article, e.g. a tire subject to harsh driving conditions. In fact, it has been acknowledged by tire specialists and cord manufacturers that adhesion retention is severely affected by humidity ageing and related effects causing degradation, involving heat corrosion, and that a high initial adhesion level achieved for a given brass coating is no guarantee of maintaining a satisfactory adhesion level during the lifetime of e.g. a tire. Seeking optimization of the brass coating, in particular a solution to the humidity ageing problems for a given rubber compound, results in most cases in the use of thinner brass layers with low copper content. Unfortunately, this solution suffers from some practical difficulties, such as e.g. a lower initial adhesion, corrosion problems and poor wire drawability, especially when the brass composition has a copper content below 65%.
In the past, a number of attempts have been made to solve the difficulties posed by the presence of moisture and by the simultaneous action of humidity and heat.
These trials include the modification of the brass coating by alloying Cu-Zn with different metals, such as Co, Ni, Pb, Sn and even Fe, so as to obtain a homogeneous ternary brass alloy. Other proposals include the deposition of a protective metal layer of Ni or Zn between the steel substrate and the brass coating, the treatment of the brass surface with various chemicals to clean the brass surface in depth and/or modification of the outermost layer with adhesion promoters and/or corrosion inhibitors. In addition the deposition of a thin corrosion resistant metal film of zinc and the alloying of the brass surface with cobalt have been proposed.
A number of these methods are described in the following prior art documents:
U.S. Pat. No. 3,858,635 proposes the use of Sn, Pb and the like.
U.S. Pat. No. 3,749,558 describes the use of Cu-Ni and Cu-Ni Zn coatings
U.S. Pat. No. 4,299,640 proposes the treatment of the brass surface with certain amino carboxylic acids and their salts.
U.K. Pat. No. 2,011,501A describes the use of ternary brass alloy coatings containing Cu, Zn and Co.
U.S. Pat. No. 2,076,320 describes brass-coated metal objects with a high cobalt concentration gradient on their surface.
U.S. Pat. No. 4,143,209 describes a process for plating a brass-coated wire with a zinc layer.
U.S. Pat. No. 4,446,198 reveals a ternary brass alloy coating containing Cu, Zn and Fe.
Some of these attempts have been successful in solving one or another specific aspect of the brass to rubber adhesion problem. However, there still remain deficiencies and uncertainties.
In practice, the use of ternary brass alloy coatings is less reliable because of more frequent compositional fluctuations, a complex process, and the difficulty in maintaining close tolerances over a long manufacturing period. When using low melting-point metals on top of the brassed wire, it is found that they migrate to a variable degree in the brass layer during the wire drawing process. Cobalt deposits are expensive, less deformable and sometimes detrimental, depending on vulcanization conditions and rubber type.
Thus, none of the proposed methods to prevent loss of rubber adhesion to conventionally prepared wires or to wires with modified brass coating are sufficiently successful to find widespread commercial use. They are often unable to tackle the stated problem in its entirety, i.e. the pursuit of adhesion retention under varying working conditions when combining brass coatings and rubber compounds of different origin, preferably without sacrificing too much in terms of manufacturing reliability and wire cost.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a novel composite brass coating capable of improving adhesion retention in various rubber compounds after curing.
According to the present invention, a steel element for reinforcing rubber articles has a rubber adherable coating comprising a layer of a copper-zinc alloy containing at least 50% of copper, and at least one additional separate outer film of a metal or a metal alloy selected from the group containing iron, nickel, manganese, chromium, molybdenum, vanadium, titanium, zirconium, niobium, tantalum, hafnium and tungsten, said outer film having a thickness of from 0.0005 to 0.05 μm.
The separate film is, preferably, prepared by electrolytic plating of a single metal or a metal alloy selected from the group comprising iron, nickel, manganese and chromium, and said separate film has a thickness ranging from 0.0005 to 0.05 μm, preferably from 0.001 to 0.020 μm. When considering also special deposition techniques, the group of suitable metallic top coatings can be extended to include other high-melting metals such as vanadium, titanium, tungsten, zirconium, niobium, hafnium, molybdenum and tantalum. Such metals can be applied by vacuum deposition techniques (chemical, vapour deposition, sputtering, ion plating, etc.), by electrodeposition from molten salts or by electroplating from specialty non-aqueous solutions.
For carrying the present invention into effect, it is particularly advantageous to select the metals iron, nickel and manganese and most preferably iron, nickel and nickel-iron alloys, said metals being easily electroplated and showing good deformability.
The outer film may be a single metal layer of iron, nickel or manganese or a binary alloy such as NiFe, NiMn or NiCr. The outer film may have a thickness of from 0.001 to 0.02 μm, and the brass layer a thickness of from 0.05 μm to 0.5 μm, or preferably from 0.1 to 0.35 μm, the brass comprising from 55 to 75% of copper.
When the element is a wire, it may have a typical diameter of from 0.08 to 0.5 mm and a tensile strength of at least 2500 N/mm 2 . The wire may be twisted with other wires to form a steel cord. The cord may be made from wires already covered with the composite coating, or the outer film may be applied to the cord after the brassed wires are twisted together. As a result, it may not be necessary for all the wires forming the cord to be provided with the outer film, depending on the cord construction. Alternatively, when the wire is coated before twisting, the outer film may be provided either at an intermediate stage before the wire is drawn to its final size, or after such a drawing step. Additionally, the brass layer may include an additional ternary alloying component.
It has now been found that steel wire and steel cord plated with a composite brass coating exhibit an improved resistance to adhesion degradation when embedded in a vulcanized rubber article and exposed to moisture and heat, which is rather surprising in the light of the prior art experiences and knowledge.
As a consequence, plated cords, which are a specific embodiment of this invention, are very useful for reinforcing rubber tire material, because vehicle tires are often subject to heat build-up and water pick-up during running.
To simulate tire-exposure conditions involving heat and humidity, test samples of steel cord encased in different tire rubber compounds were prepared and after vulcanization held for a given time in a wet ageing environment (95% relative humidity at about 70°-80° C.; humidity ageing), or in a steam atmosphere (steam ageing at 120° C.). After ageing the well-known TCAT-test (Tire Cord Adhesion Test) was carried out which measures the pull-out force or the adhesion to rubber of the cords.
A steel substrate such as e.g. a high carbon steel wire for tire cord may be treated as follows to obtain a multi-layer composite coating:
1. Heat treatment (patenting) at an intermediate wire size
2. Pickling and rinsing
3. Brass plating
4. Rinsing and pretreatment of the brass surface
5. Deposition of at least one additional metal layer
6. Rinsing and drying
7. Wire drawing to a fine wire size and twisting the wires into cords.
Variations of this process are of course possible. For instance, the inner brass coating can be obtained from an electrolytic brass alloy plating bath or can be prepared by depositing two successive layers of copper and zinc onto the steel wire followed by heating the coated wire to form a diffused brass alloy layer. In any case, a homogeneous brass alloy is present before applying the separate outer metal layer so as to form a composite adhesion coating. For tire applications the brass alloy coating, forming here the inner layer of the new composite coating, has a copper content from 55 to 75%, preferably from 60 to 72%, and a thickness ranging from 0.05 to 0.50 μm, preferably from 0.12 to 0.35 μm.
An alternative method to produce a composite brass coated wire material is to apply at least one separate metal film on the drawn brassed wire or on the finished cord.
The metal layer or layers on top of the brass can be a single metal chosen from iron, nickel, manganese, chromium, molybdenum, tungsten, zirconium, tantalum, titanium or an alloy of these metals. Preferably, the top coating consists of one layer of a metal selected from iron, nickel, chromium or manganese or of a binary alloy of these elements (Ni-Fe, Ni-M, Ni-Cr, Fe-Cr, etc.), and most preferably of Fe, Ni, Mn or Ni-Fe or Ni-Mn alloy. In fact, the most preferred metals are those which are readily electroplated, are not expensive and exhibit a good plastic deformation capacity. The thickness of the plated toplayer ranges from 0.0005 to 0.050 μm, preferably from 0.001 to 0.020 μm. Below a lower limit of 0.0005 μm it is difficult to achieve or to maintain a uniform surface coverage, and above 0.05 μm it becomes difficult to draw the wire without disturbing the composite coating constituents and to control the adhesion reaction.
The use of a composite brass coating instead of a ternary brass alloy containing one of the previously mentioned metals as ternary alloying elements has the advantage that the selected metal doesn't interfere with the Cu-Zn-diffusion treatment or the brass alloy plating procedure. There is less metal needed because it is not distributed in the much thicker brass coating, the obtainable effect is significantly larger because the metal film is present in a concentrated amount at the interface between rubber and brass and it is effective on thin as well as on thick brass layers.
It is not quite clear why a composite brass coating is so unexpectedly beneficial with respect to adhesion retention after vulcanization and humidity ageing.
A possible explanation may be found by studying the theory of rubber to brass adhesion. According to this theory, generally agreed upon by those skilled in the art, the adhesion of rubber to brass is dependent upon a bond between the copper in the brass and the sulphur in the rubber. It is believed that this bond involves the formation of polysulphur metal bridges of the type Cu-Sx-rubber and of a thin layer of cupreous sulphide at the brass rubber interface. When humidity and heat intervene after vulcanization, the curing reaction may proceed further (probably by catalytic activation of copper in the presence of water and heat, this is the overcuring effect). As a result of the continued reaction between copper and sulphur, more cupreous sulphide is formed at the brass/rubber interface than is needed for maximum adhesion and the thickened Cu 2 S-layer become friable, thereby facilitating interface debonding. It is also possible that the postcuring reactions locally destruct a lot of adhesion bridges (sulphur consumption for Cu 2 S and even CuS-formation) and that it weakens the rubber interface by sulphur liberation and migration. These combined effects induce adhesion degradation, which may continue with ageing, as long as there is enough copper and sulphur available. This has been confirmed in practice by investigating adhesion levels of humidity aged rubber to cord bonds: indeed thick brass coatings and high-Cu brass compositions were found to give poorer adhesion retention. When using a brass composite coating, adhesion deterioration by postcure moisture and heat accumulation effects can be slowed down to a significant extent. This rather unexpected result, caused by the presence of a separate thin film of the specified metals or alloys on top of the brass, may be explained by diffusion barrier action any by its regulating effect on Cu-activity and on the interfacial Cu 2 S-reaction. It is plausible that the selected metals, which have two things in common--namely a rather slow diffusability in brass and a sulphide forming capacity--are the most suitable for this purpose.
Further advantages of the improved resistance of the composite-brass coating material to rubber bond deterioration by postcure heat and humidity are related to new processes and applications involving high-temperature curing. This short-cycle vulcanization method carried out at a rather elevated temperature (typically above 160° C.) is generally too critical for conventional brass coatings.
The reinforcing steel elements, such as e.g. wire, cable tire and cord, produced from the coated steel substrates, can be incorporated into a variety of rubber articles such as tire, hose, conveyor belt and the like. Of course, high-duty tires such as heavy-load truck tires, long lasting tires suitable for remolding and other high-performance tires requiring improved adhesion retention are preferred articles to be strengthened by the reinforcing elements of this invention, which can be encased in various reinforcement plies, such as tire-carcass plies, tire belt, breaker piles and chippers.
DETAILED DESCRIPTION OF THE INVENTION
Such embodiments of the invention will now be described with reference to the following Examples and description:
A conventional brass-plated wire or cord process is adapted to produce the composite-brass coating previously described. For this purpose, the wire substrate, after the last brass deposition which typically comprises the alternate electroplating of a copper layer and a zinc layer followed by thermal diffusion to form a brass alloy layer of the prescribed composition and thickness, is chemically pretreated to activate its brassed surface and next is covered with a thin metal or binary metal alloy film selected from Fe, Ni, Mn and the like (preferably Fe, Ni, Ni-Fe or Ni-Mn) by moving the pretreated wire through an electrolytic bath of the selected metal or alloy. Depending on the metal or alloy plate, electroplating solutions may be prepared from various electrolytes: a chloride bath, a sulphate bath, a sulfamate bath, a fluoroborate bath or a cyanide bath. Adequate activation of the brass alloy coated substrate is needed to obtain good surface coverage and adherence of the plated metal film. Therefore, the brassed substrate is chemically pretreated, such as e.g. in a peroxide based solution, in a potassium pyrophosphate bath (e.g. aqueous solution with 100 g/l of K 4 P 2 O 7 at 50° C.), in a dilute phosphoric acid or in a citric acid bath and the like.
The adhesion tests were carried out on vulcanized rubber samples containing steel cord of 2+2×0.25 mm construction. A prior art standard cord of this type was prepared as follows: patented 0.70% C-steel wires of 1.25 mm diameter were covered electrolytically with a prescribed amount of copper and zinc and suitably heated to form a 0.95 μm thick difffused brass alloy coating containing 65% copper and 35% zinc. The wires were then drawn to a diameter of 0.25 mm whereby the brass layer was reduced to a thickness of about 0.19 μm. These wires were twisted together to form a strand of 2+2×0.25 mm. In addition to this standard cord, similar cords were produced from the same wire material, which cords were provided with various conventional and composite brass coatings. These cord samples are described in the following examples, which include comparative examination of their adhesion behaviour in a number of rubber compounds, in particular their capability to resist bond degradation by humidity ageing.
Starting with the same wire material as for standard cords, the wire being first covered with a brass diffusion alloy coating, two different composite-brass coated cords were prepared, one with an iron and one with a nickel top layer respectively.
EXAMPLE 1
Patented steel wires of 1.25 mm diameter, just after forming the brass alloy coating, were pretreated in a cold phosphoric acid solution and subsequently covered electrolytically from, in one case, a ferrous sulphate bath (290 g/l FeSO 4 . 7 aq; 10 g/l NaCl; pH=2.5; 50° C.) to produce a thin iron film of 0.028 μm, whereas in the other case, a thin Ni-film was plated (by a Watts bath) on the brass coating. After wire drawing to 0.25 mm and a tensile strength greater than 2800 N/mm 2 , and twisting the wires to cords 2+2×0.25 mm, the composite adhesion coating on the cord surface displayed a two-layer composition consisting of a brass layer of 0.19 μm and of an iron layer, or a nickel layer, respectively, of about 0.005 μm. Those cords were embedded in rubber and vulcanized to form test samples of which the initial adhesion and humidity aged adhesion (48 hours at 77° C. in 90% relative humidity atmosphere) were determined. The used rubber compound was a commercial tire rubber (compound A1 of tyre builder A).
TABLE 1______________________________________Adhesion results of 2 + 2 × 0.25cord in tire rubber compound A1 Adhesion force (in Newtons)Coating type initial aged humidly______________________________________(1) 0.19 μm brass 422 149 64.5 Cu - 35.5 Zncomposite coatings(2) brass 0.19 μm as (1) + 433 203 0.005 μm Fe film(3) brass 0.19 μm as (1) + 440 230 0.005 μm Ni film______________________________________
The results demonstrate the superiority of the composite adhesion coating over the conventional brass coating (1) in adhesion retention. The composite brass coating displays also a favorable initial adhesion level.
EXAMPLE 2
In a second series of tests (using 0.25 mm wire and 2+2×0.25 mm cord) the conventional brass diffusion coating has been changed in composition and thickness, and is compared with a composite coating containing the same brass alloy covered by a thin metal film of iron or nickel. The postcure adhesion level was determined after the steam ageing of vulcanized rubberized cord samples at 120° C. (rubber compound A2 of tire builder A). The basic brass alloy compositon contained 70% of copper and 30% of zinc.
TABLE 2______________________________________Adhesion results before and aftersteam ageing (2 + 2 × 0.25 mm cord) Adhesion force (Newtons)Type of coating steam aged at 120° C.(70 Cu - 30 Zn alloy) initial 12 hrs 24 hrs______________________________________Conventional0.15 um brass 320 310 2370.25 um brass 290 278 225Composite coating0.15 um brass + 0.0012 um Fe 370 325 2510.25 um brass + 0.0020 um Fe 380 355 2700.15 um brass + 0.005 um Ni 340 315 2690.25 um brass + 0.005 um Ni 377 387 296______________________________________
It can be seen that a very thin surface film of iron or nickel is already effective in improving adhesion retention after steam ageing.
EXAMPLE 3
In this example cords 2+2×0.25 mm, embedded in the same rubber compound as used in example 2, are vulcanized at 160° C. for different cure times in order to assess the adhesion behaviour in overcuring conditions. Conventional diffusion brass coatings of varying composition are compared with composite coatings. The results are summarized in table 3.
TABLE 3______________________________________Adhesion values of rubberized cords2 + 2 × 0.25 mm after curing at 160° C. Adhesion force (Newtons) with increasing curing time (in minutes)Type of coating 15 25 35 60______________________________________conventional brass0.15 μm - 61% Cu 349 385 408 3760.25 μm - 61% Cu 385 450 420 4150.25 μm - 71% Cu 397 375 310 3080.20 μm - 65% Cu 382 452 408 338composite coating0.15 μm brass of 61% Cu + 358 438 422 4040.0012 μm Fe0.25 μm brass of 61% Cu + 385 440 433 4130.0020 μm Fe0.25 μm brass of 71% Cu + 387 405 385 3850.0031 μm Fe0.20 μm brass of 65% Cu + 388 430 447 4050.004 μm Fe0.20 μm brass of 65% Cu + 305 433 440 3930.007 μm Ni0.25 μm brass of 71% Cu + 253 375 388 3720.010 μm Ni______________________________________
The tabulated results show that a thin metal film of iron or nickel deposited on top of a brass coating is very suitable for maintaining high adhesion values over long curing times, regardless of brass composition. The beneficial effect is most pronounced in brass of high copper content.
EXAMPLE 4
In example 4 a tire rubber compound of tire manufacturer B was chosen for assessing the broad applicability of the coated cords of the present invention. The initial adhesion and steam aged adhesion were determined of vulcanized cords having a conventional brass coating, and a composite brass coating consisting of a common brass alloy layer covered by a metal film of iron, nickel or manganese.
A manganese metal film was electroplated on the brassed wire from a sulphate bath containing 100 g/l MnSO 4 . 2 aq (and 10 g/l boric acid) at a pH of 4-5 at 40° C.
TABLE 4______________________________________Adhesion values (Newtons) of rubberizedcords 2 + 2 × 0.25 mm in rubber compound B Initial Steam aged adhesionCoating type adhesion 16 hrs-120° C. 32 hrs-120° C.______________________________________0.25 μm brass of 423 265 15671% Cu0.25 μm brass of 468 363 23071% Cu + 0.0035μm Fe0.25 μm brass of 440 401 24171% Cu + 0.0065μm Ni0.25 μm brass of 403 338 23371% Cu + 0,0042μm Mn0.20 μm brass of 416 375 28964% Cu0.20 μm brass of 421 426 36464% Cu + 0.0012μm Fe0.20 μm brass of 444 403 35164% Cu + 0,0050μm Ni0.20 μm brass of 430 415 34564% Cu + 0,0030μm Mn______________________________________
From table 4 it can be noticed that the composite brass coatings significantly improve the adhesion retention of vulcanized cord/rubber (compound B) after simulated heat and humidity ageing.
The examples and simulation test data clearly show that a composite coating characterized by an inner Cu-Zn or brass alloy layer and a distinct surface film of a metal is remarkably advantageous in improving the adhesion behaviour of reinforced rubber articles throughout the useful life of the vulcanized laminate in which the reinforcing elements (e.g. steel cord in a tire laminate) are plated with such composite brass layers
Similar promising results were obtained by electrodeposition of a thin alloy film of NiMn or NiFe on top of the brass. For example, a NiFe-bath suitable for alloy plating of a NiFe-alloy comprising 10 to 30% Fe contains about 45 g/l of nickel and 3 to 5 g/l of iron (together with a hydroxycarboxylic acid stabilizer) and is operated at 55°-60° C., at a pH of 3-3.5 and current densities of 3-4 A/dm 2 or higher (with air agitation). A Ni-Mn alloy layer on top of the brass is electrodeposited from a Ni-sulfamate bath containing a variable amount of Mn-sulfamate as required for the desired alloy codeposition. The observed improvement in adhesion retention in these cases was at least 15%.
While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein--in particular with respect to specific selections of multi-layer combinations of the previously mentioned metallic elements and alloys--without departing from the scope of the present invention.
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A steel element for reinforcing a rubber article comprises a brass layer and at least one additional outer film of metal or metal alloy selected from the group containing Fe, Ni, Mn, Cr, Mb, Va, Ti, Zi, Nb, Ta, Hf and W.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to two provisional patent Applications Nos. 61/661,619 and 61/661,622 filed on Jun. 19, 2012. The disclosure of the prior applications are incorporated herein by reference.
TECHNICAL FIELD
The invention generally relates to high volume low speed (HVLS) fans, and more specifically HVLS fans utilizing short take off and landing (STOL) technology.
BACKGROUND OF THE INVENTION
Interior climate control and air circulation is difficult in certain applications, particularly including large open structural areas such as found in a factory or warehouse setting. This difficulty is encountered in both hot and cold seasonal conditions, where heat during cold weather heating migrates towards the ceiling of a building and humidity tends to migrate down during hot and humid weather conditions. Therefore, there is an interest in forcing air from the ceiling, down, towards an occupied main floor during cooler weather, thus saving costs for heating, and circulating air more generally in warmer weather conditions resulting in a perceived cooler environment due to evaporation. Solutions to these conditions include forced ventilation through ceiling-based plenums in HVAC applications. Another solution is the use of ceiling fans to circulate the ambient air. However, both of these solutions are inadequate for circulating large volumes of air in large open areas such as is common in a factory or warehouse setting.
HVLS fans provide improvement over HVAC systems and/or traditional ceiling fans by moving larger volumes of air. These systems have their own limitations including relatively low efficiency in both the amount of energy used and amount of circulated air per unit of energy use.
STOL technology is a known solution for allowing aircraft to take off and land within constrained short distances. STOL technology has been adapted to aircraft airfoil profiles for providing improved lift and efficient movement of air under slower take off or landing speeds. Known aircraft wing profiles utilizing STOL design technology include EPPLER-420 and FX63-137 profiles. But, these airfoil profiles utilizing STOL design technology have not been adapted for use in HVLS fan systems.
In addition, due to their size and weight resulting from fans reaching diameters from 12 feet to 20 feet, or more, there is risk to persons and equipment below the fan in the event of a failure causing a portion, or all, of the fan to fall.
Therefore, there is opportunity and need for improving air circulation systems in large open areas. Further, there is need for improving HVLS fan systems to provide higher efficiencies and maximize airflow in large open spaces such as warehouses, manufacturing facilities, places of worship, gymnasiums/health clubs, auto dealerships and more. There is also a need for providing safety measures in the implementation of HVLS fan systems.
SUMMARY OF THE INVENTION AND ADVANTAGES
The present disclosure addresses these needs and issues by providing an HVLS fan system incorporating STOL technology in a system that increases air volume and circulation while also increasing efficiencies and which does not add significant costs, weight, or manufacturing complexity to this system.
It is therefore an object of the disclosure to take advantage of STOL technology and thus increase efficiency of an HVLS fan system. It is a further object of the disclosure to provide greater efficiency in the movement of air in the HVLS system. It is an additional object of the disclosure to provide an economical and lightweight solution to better circulate air in large areas. Another object of the disclosure is to provide a safety mechanism for preventing injury or damage in the event of a failure in the HVLS fan.
The present disclosure provides an HVLS fan system utilizing STOL technology and having better efficiency, including an airfoil form adapted to provide higher airflow at lower circulation rates while decreasing drag on the airfoils and increasing efficiencies. The system also includes an airfoil profile consistent with STOL technology. More particularly, an airfoil utilizing an EPPLER 420 or substantially similar airfoil design. In addition, the system includes a wing tip advantageously formed to reduce drag of the airfoil. Further, the system employs a hub displacing the airfoil at an angle most suitable for maximizing the benefits of the STOL technology. More particularly, this includes a hub providing an attachment angle of between seven and ten degrees to the airfoil, and even more particularly eight degrees to the airfoil. Together, the disclosure provides an HVLS fan system offering improved efficiency, reduced drag, and increased air flow for the benefit of better circulating air in a large open area.
In addition, the system includes a safety system including attachment of a retaining member, one for each airfoil, on the hub that passes through a retaining bracket in a manner that in the event of the airfoil becoming dislodged from the hub or the hub itself becoming disconnected from the drive system prevents the hub and/or the airfoils from falling. The retaining brackets do not touch or otherwise notably increase air resistance in the system but provide for an important safety measure where failure can cause catastrophic consequences. Another safety aspect is a series of overlapping brackets which mount on the top of the airfoils which interlock each of the airfoils to the one next to it. This will prevent an airfoil from becoming dislodged from the system in the case of failure. In addition, guy wires connect the frame of the HVLS fan system to a support member such as a ceiling support beam.
Other objects and features of the present invention will become apparent when viewed in the light of the detailed description of the preferred embodiments when taken in conjunction with the attached drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a perspective view of the HVLS fan system of the invention;
FIG. 2 is a side sectional view in spaced apart form showing the HVLS fan system of FIG. 1 ;
FIG. 3 is a side cross sectional view of an airfoil of the HVLS fan system;
FIG. 4 is a top view of an airfoil of the HVLS fan system;
FIG. 5 is a side view of a wingtip fence of the HVLS fan system;
FIG. 6 is a top view of the wingtip fence of FIG. 5 ;
FIG. 7 is a back view of the wingtip fence of FIG. 5 ;
FIG. 8 is a top view of a central hub of the HVLS fan system;
FIG. 9 is a side view of the central hub of FIG. 8 ;
FIG. 10 is a perspective view of a cylinder of the HVLS fan system;
FIG. 11 is a cross-sectional view of the cylinder of FIG. 11 ;
FIG. 12 is a top view of a securing plate of the HVLS fan system;
FIG. 13 is a perspective view a of portion of the HVLS fan system in spaced apart form emphasizing the locations of safety brackets; and
FIG. 14 is a table containing X-Y data coordinates for the airfoil profile of the HVLS fan system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following figures, like reference numerals are used to identify identical components in the various views and embodiments. The following example is meant to be illustrative of preferred embodiments for the invention. However, those skilled in the art will recognize various additional alternative embodiments.
Referring to FIGS. 1-13 , an HVLS fan system 10 of the disclosure includes airfoils 12 coupled at one end to a central hub 14 and extending in the other direction to a distal end having a wingtip fence 16 . The central hub 14 is coupled to a motor 18 for rotating the airfoils 12 . The motor 18 is connected to a frame 20 which is coupled to a lower yoke 22 and an extension bar 24 which in turn is coupled to an upper yoke 26 . The upper yoke 26 is illustrated as connected to a building member 28 such as a girder or other similar structures suitable for bearing the weight of the HVLS fan system. The extension bar 24 as a backup secures the HVLS fan system to the building member 28 with a safety cable 30 . Guy wires (not shown) are also used to secure the frame to weight bearing locations on either the builder member 28 or other support structure in the ceiling of the building. Typically, four guy wires are used and attached at somewhat equally spaced locations around the HVLS fan system.
As illustrated, the HVLS fan system has six airfoils 12 equally spaced around the central hub 14 . The HVLS fan system airfoils 12 are generally positioned between ten feet and fifty feet above the floor with optimum height generally between twenty feet and thirty feet. The motor 18 is a standard approximately one horsepower electric motor known to those skilled in the art. To accomplish the objective of HVLS, the airfoils 12 are each between five and twelve feet in length and more preferably between six and ten feet in length. Looking up at an installed HVLS fan system 10 it will rotate in a counterclockwise direction 32 .
The airfoils 12 are formed out of a lightweight material such as aluminum or a composite metal that can be formed into an airplane wing type shape with a hollow core. However, it should be appreciated that the airfoils can be formed of a variety of different materials, including plastics, polyurethanes, and other suitably rigid materials adequate to form an airfoil, or even combinations of such materials known to those skilled in the art. It should also be appreciated that the length of the airfoils 12 can be increased or decreased to suit a certain application. In addition, it should be appreciated that the HVLS fan system 10 can include airfoils 12 without inclusion of wingtips fences 16 . Further, motor 18 may be any manner of other suitable motor including suitable horse power or amperage rating know to those skilled in the art.
The airfoils 12 are fan blades comprised of a generally elliptical top surface 34 and a generally elliptical bottom surface 36 . The airfoils 12 are configured to mount to the central hub 14 through the use of an H-shaped connector member 37 , connected on one end to the central hub 14 and on the other end to a receptors 39 interior to the airfoil 12 . The airfoil further includes a leading edge 38 and a trailing edge 40 . The trailing edge 40 maintains a radius of approximately 0.043 inches.
The airfoil may be a substantially hollow extruded aluminum section of approximately 0.1 inches in thickness when mounted to the central hub 14 including STOL-type airfoils. The wingtip fence 16 has a substantially vertical member 42 with a connecting perimeter 44 defined by the profile of the airfoil 12 , to which it is attached. The wingtip 16 consisting of a lower concave edge 46 , an upper convex edge 48 , a leading 50 and trailing edge 52 which sits flush with the airfoil 12 end edge. The vertical member 42 protrudes rearward relative to the leading edge 50 of the airfoil 12 . The vertical member 42 consists of two planes. The lower plane is parallel to the connection plane of the airfoil and wingtip fence, while the upper plane is angled outward relative to the innermost end of the airfoil. Adding the wingtip fence 16 to the airfoils 12 improves the aerodynamic properties of the airfoils, by reducing drag and therefore increasing the fan's overall efficiency.
The wingtip fence 16 includes a mounting member 54 which connects to an inner portion of the receptors 39 of the airfoil 12 . The wingtip 16 is configured to secure the connection to the airfoil 12 through protruding guide points 56 that couple to an inner perimeter of the airfoil 12 thus mounting the wingtip fence 16 to the airfoil 12 .
The central hub 14 provides a securing system for the fan assembly, where a bottom frame member 58 is connected to a securing plate 60 by fasteners 62 . The central hub 14 assembly includes a cylinder 64 coupled to the central hub 14 and retaining members 68 , one for each of the airfoils 12 that when connected to the central hub 14 extend through an opening in the securing plate 60 thus providing a safety stop against a failure involving a break in the motor 18 or its coupling to the cylinder 64 or a drive shaft 70 . The cylinder 64 has an opening 72 for receiving the drive shaft 70 . The drive shaft 70 does not connect directly to the cylinder 64 , but instead couples to a bushing (not shown) which couples the drive shaft 70 to the cylinder 64 through simultaneous expansion and contraction, as is known to those skilled in the art.
The central hub 14 includes flanges 74 which are displaced from a plane defining the central hub at an angle predetermined for the airfoils 12 . The angle of the flanges 74 positions the airfoils 12 at an angle most suitable for maximizing the benefits of the STOL technology. More particularly, this includes an attachment angle of between seven and ten degrees to the airfoil, and even more particularly eight degrees to the airfoil.
Another safety aspect is a series of overlapping brackets including a first bracket 76 and second bracket 78 which mount on the top of the airfoils and interlock each of the airfoils 12 to the one next to it. The first bracket 76 and second bracket 78 are held in place with fasteners 80 . This prevents the airfoil 12 from becoming dislodged from the system in the event of failure. In addition, guy wires (not shown) connect the frame of the HVLS fan system to a support member such as a ceiling support beam.
After applicants first conceived that STOL technology would benefit efficiencies and overall performance of an HVLS fan, experimentation was undertaken under preset parameters and requirements to optimize a STOL airfoil profile. This experimentation, undertaken at the request and direction of the applicants by Haiyer Lou, Ph.D, M. Eng at TurboMoni, confirmed that of two airfoil profiles adapting STOL technology an airfoil following EPPLER-420 parameters was more efficient when angled at approximately 8 degrees from horizontal. Thus, referring to FIG. 14 , the airfoils 12 are predetermined to comply with STOL technology and provide high efficiency operation including higher lift and lower drag for the application of an HVLS fan. The EPPLER-420 profile disclosed in FIG. 14 provides dimensionless cord lengths that provide for defining X-Y coordinates by multiplying with the real cord (the distance from leading edge point to the trailing edge point).
Thus, an HVLS fan system of the invention, including its various embodiments, provides a high efficiency cost effective, secure means of addressing and providing air movement in large open areas.
While particular embodiments of the invention have been shown and described, numerous variations and alternative embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
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An HVLS fan system uses STOL technology for airfoils and angle of attack thus optimizing air movement efficiency and reducing drag. The HVLS fan system includes wingtip fence end caps to the airfoils for improving efficiency by reducing drag. The HVLS fan system also includes an interconnection of the airfoils to a securing plate thus providing a failsafe and reduced potential for damage or injury resulting from failure of the connection between the airfoil array and a drive unit such as an electric motor and associated gearing.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of co-pending application Ser. No. 10/123,389, filed on Apr. 16, 2002, which claims the benefit of Provisional application Ser. No. 60/284,465 filed Apr. 18, 2001, which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to novel arylindenopyridines and their therapeutic and prophylactic uses. Disorders treated and/or prevented using these compounds include neurodegenerative and movement disorders ameliorated by antagonizing Adenosine A2a receptors and inflammatory and AIDS-related disorders ameliorated by inhibiting phosphodiesterace activity.
BACKGROUND OF THE INVENTION
Adenosine A2a Receptors
Adenosine is a purine nucleotide produced by all metabolically active cells within the body. Adenosine exerts its effects via four subtypes of cell-surface receptors (A1, A2a, A2b and A3), which belong to the G protein coupled receptor superfamily (Stiles, G. L. Journal of Biological Chemistry, 1992, 267, 6451). A1 and A3 couple to inhibitory G protein, while A2a and A2b couple to stimulatory G protein. A2a receptors are mainly found in the brain, both in neurons and glial cells (highest level in the striatum and nucleus accumbens, moderate to high level in olfactory tubercle, hypothalamus, and hippocampus etc. regions) (Rosin, D. L.; Robeva, A.; Woodard, R. L.; Guyenet, P. G.; Linden, J. Journal of Comparative Neurology , 1998, 401, 163).
In peripheral tissues, A2a receptors are found in platelets, neutrophils, vascular smooth muscle and endothelium (Gessi, S.; Varani, K.; Merighi, S.; Ongini, E.; Borea, P. A. British Journal of Pharmacology, 2000, 129, 2). The striatum is the main brain region for the regulation of motor activity, particularly through its innervation from dopaminergic neurons originating in the substantia nigra. The striatum is the major target of the dopaminergic neuron degeneration in patients with Parkinson's Disease (PD). Within the striatum, A2a receptors are co-localized with dopamine D2 receptors, suggesting an important site of for the integration of adenosine and dopamine signaling in the brain (Fink, J. S.; Weaver, D. R.; Rivkees, S. A.; Peterfreund, R. A.; Pollack, A. E.; Adler, E. M.; Reppert, S. M. Brain Research Molecular Brain Research, 1992, 14, 186).
Neurochemical studies have-shown that activation of A2a receptors reduces the binding affinity of D2 agonist to their receptors. This D2R and A2aR receptor-receptor interaction has been demonstrated in striatal membrane preparations of rats (Ferre, S.; von Euler, G.; Johansson, B.; Fredholm, B. B.; Fuxe, K. Proceedings of the National Academy of Sciences of the United States of America, 1991, 88, 7238) as well as in fibroblast cell lines after transfected with A2aR and D2R cDNAs (Salim, H.; Ferre, S.; Dalal, A.; Peterfreund, R. A.; Fuxe, K.; Vincent, J. D.; Lledo, P. M. Journal of Neurochemistry, 2000, 74, 432). In vivo, pharmacological blockade of A2a receptors using A2a antagonist leads to beneficial effects in dopaminergic neurotoxin MPTP(1-methyl-4-pheny-l,2,3,6-tetrahydropyridine)-induced PD in various species, including mice, rats, and monkeys (Ikeda, K.; Kurokawa, M.; Aoyama, S.; Kuwana, Y. Journal of Neurochemistry, 2002, 80, 262). Furthermore, A2a knockout mice with genetic blockade of A2a function have been found to be less sensitive to motor impairment and neurochemical changes when they were exposed to neurotoxin MPTP (Chen, J. F.; Xu, K,; Petzer, J. P.; Staal, R.; Xu, Y. H.; Beilstein, M.; Sonsalla, P. K.; Castagnoli, K.; Castagnoli, N., Jr.; Schwarzschild, M. A. Journal of Neuroscience, 2001, 21, RC143).
In humans, the adenosine receptor antagonist theophylline has been found to produce beneficial effects in PD patients (Mally, J.; Stone, T. W. Journal of the Neurological Sciences, 1995, 132, 129). Consistently, recent epidemiological study has shown that high caffeine consumption makes people less likely to develop PD (Ascherio, A.; Zhang, S. M.; Hernan, M. A.; Kawachi, I.; Colditz, G. A.; Sp izer, F. E.; Willett, W. C. Annals of Neurology, 2001, 50, 56). In summary, adenosine A2a receptor blockers may provide a new class of antiparkinsonian agents (Impagnatiello, F.; Bastia, E.; Ongini, E.; Monopoli, A. Emerging Therapeutic Targets, 2000, 4, 635).
Phosphodiesterase Inhibitors
There are eleven known families of phosphodiesterases (PDE) widely distributed in many cell types and tissues. In their nomenclature, the number indicating the family is followed by a capital letter that indicates a distinct gene. A PDE inhibitor increases the concentration of CAMP in tissue cells, and hence, is useful in the prophylaxis or treatment of various diseases caused by the decrease in cAMP level which is induced by the abnormal metabolism of CAMP. These diseases include conditions such as hypersensitivity, allergy, arthritis, asthma, bee sting, animal bite, bronchospasm, dysmenorrhea, esophageal spasm, glaucoma, premature labor, a urinary tract disorder, inflammatory bowel disease, stroke, erectile dysfunction, HIV/AIDS, cardiovascular disease, gastrointestinal motility disorder, and psoriasis.
Among known phosphodiesterases today, PDE1 family are activated by calcium-calmodulin; its members include PDE1A and PDE1B, which preferentially hydrolyze cGMP, and PDE1C which exhibits a high affinity for both CAMP and cGMP. PDE2 family is characterized as being specifically stimulated by cGMP. PDE2A is specifically inhibited by erythro-9(2-hydroxy-3-nonyl)adenine (EHNA). Enzymes in the PDE3 family (e.g. PDE3A, PDE3B) are specifically inhibited by cGMP. PDE4 (e.g. PDE4A, PDE4B, PDE4C, PDE4D) is a cAMP specific PDE present in T-cells, which is involved in inflammatory responses. A PDE3 and/or PDE4 inhibitor would be predicted to have utility in the following disorders: autoimmune disorders (e.g. arthritis), inflammatory bowel disease, bronchial disorders (e.g. asthma), HIV/AIDS, and psoriasis. A PDE5 (e.g. PDE5A) inhibitor would be useful for the treatment of the following disorders: cardiovascular disease and erectile dysfunction. The photoreceptor PDE6 (e.g. PDE6A, PDE6B, PDE6C) enzymes specifically hydrolyze cGMP. PDE8 family exhibits high affinity for hydrolysis of both cAMP and cGMP but relatively low sensitivity to enzyme inhibitors specific for other PDE families.
Phosphodiesterase 7 (PDE7A, PDE7B) is a cyclic nucleotide phosphodiesterase that is specific for cyclic adenosine monophosphate (cAMP). PDE7 catalyzes the conversion of cAMP to adenosine monophosphate (AMP) by hydrolyzing the 3′-phosphodiester bond of cAMP. By regulating this conversion, PDE7 allows for non-uniform intracellular distribution of cAMP and thus controls the activation of distinct kinase signalling pathways. PDE7A is primarily expressed in T-cells, and it has been shown that induction of PDE7A is required for T-cell activation (Li, L.; Yee, C.; Beavo, J. A. Science 1999, 283, 848). Since PDE7A activation is necessary for T-cell activation, small molecule inhibitors of PDE7 would be useful as immunosuppressants. An inhibitor of PDE7A would be predicted to have immunosuppressive effects with utility in therapeutic areas such as organ transplantation, autoimmune disorders (e.g. arthritis), HIV/AIDS, inflammatory bowel disease, asthma, allergies and psoriasis.
Few potent inhibitors of PDE7 have been reported. Most inhibitors of other phosphodiesterases have IC 50 's for PDE7 in the 100 μM range. Recently, Martinez, et a/. ( J. Med. Chem. 2000, 43, 683) reported a series of PDE7 inhibitors, among which the two best compounds have PDE7 IC 50 's of 8 and 13 μM. However, these compounds were only 2-3 times selective for PDE7 over PDE4 and PDE3.
Finally the following compounds have been disclosed, and some of them are reported to show antimicrobial activity against strains such as Plasmodium falciparum, Candida albicans and Staphylococcus aureus (Gorlitzer, K.; Herbig, S.; Walter, R. D. Pharmazie 1997, 504):
SUMMARY OF THE INVENTION
This invention provides a compound having the structure of Formula I
or a pharmaceutically acceptable salt thereof, wherein
(a) R 1 is selected from the group consisting of:
(i) —COR 5 , wherein R 5 is selected from H, optionally substituted C 1-8 straight or branched chain alkyl, optionally substituted aryl and optionally substituted arylalkyl; wherein the substituents on the alkyl, aryl and arylalkyl group are selected from C 1-8 alkoxy, phenylacetyloxy, hydroxy, halogen, p-tosyloxy, mesyloxy, amino, cyano, carboalkoxy, or NR 20 R 21 wherein R 20 and R 21 are independently selected from the group consisting of hydrogen, C 1-8 straight or branched chain alkyl, C 3-7 cycloalkyl, benzyl, aryl, or heteroaryl or NR 20 R 21 taken together form a heterocycle or heteroaryl; (ii) COOR 6 , wherein R 6 is selected from H, optionally substituted C 1-8 straight or branched chain alkyl, optionally substituted aryl and optionally substituted arylalkyl; wherein the substituents on the alkyl, aryl and arylalkyl group are selected from C 1-8 alkoxy, phenylacetyloxy, hydroxy, halogen, p-tosyloxy, mesyloxy, amino, cyano, carboalkoxy, or NR 20 R 21 wherein R 20 and R 21 are independently selected from the group consisting of hydrogen, C 1-8 straight or branched chain alkyl, C 3-7 cycloalkyl, benzyl, aryl, or heteroaryl or NR 20 R 21 taken together form a heterocycle or heteroaryl; (iii) cyano; (iv) a lactone or lactam formed with R 4; (v) —CONR 7 R 8 wherein R 7 and R 8 are independently selected from H, C 1-8 straight or branched chain alkyl, C 3-7 cycloalkyl, trifluoromethyl, hydroxy, alkoxy, acyl, alkylcarbonyl, carboxyl, arylalkyl, aryl, heteroaryl and heterocyclyl;
wherein the alkyl, cycloalkyl, alkoxy, acyl, alkylcarbonyl, carboxyl, arylalkyl, aryl, heteroaryl and heterocyclyl groups may be substituted with carboxyl, alkyl, aryl, substituted aryl, heterocyclyl, substituted heterocyclyl, heteroaryl, substituted heteroaryl, hydroxamic acid, sulfonamide, sulfonyl, hydroxy, thiol, alkoxy or arylalkyl,
or R 7 and R 8 taken together with the nitrogen to which they are attached form a heterocycle or heteroaryl group; (vi) a carboxylic ester or carboxylic acid bioisostere including optionally substituted heteroaryl groups
(b) R 2 is selected from the group consisting of optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl and optionally substituted C 3-7 cycloalkyl; (c) R 3 is from one to four groups independently selected from the group consisting of:
(i) hydrogen, halo, C 1-8 straight or branched chain alkyl, arylalkyl, C 3-7 cycloalkyl, C 1-8 alkoxy, cyano, C 1-4 carboalkoxy, trifluoromethyl, C 1-8 alkylsulfonyl, halogen, nitro, hydroxy, trifluoromethoxy, C 1-8 carboxylate, aryl, heteroaryl, and heterocyclyl; (ii) 'NR 12 R 11 wherein R 10 and R 11 are independently selected from H, C 1-8 straight or branched chain alkyl, arylalkyl, C 3-7 cycloalkyl, carboxyalkyl, aryl, heteroaryl, and heterocyclyl or R 10 and R 11 taken together with the nitrogen form a heteroaryl or heterocyclyl group; (iii) —NR 12 COR 13 wherein R 12 is selected from hydrogen or alkyl and R 13 is selected from hydrogen, alkyl, substituted alkyl, C 1-3 alkoxyl, carboxyalkyl, R 30 R 31 N (CH 2 ) p —, R 30 R 31 NCO(CH 2 ) p —, aryl, arylalkyl, heteroaryl and heterocyclyl or R 12 and R 13 taken together with the carbonyl form a carbonyl containing heterocyclyl group, wherein, R 30 and R 31 are independently selected from H, OH, alkyl, and alkoxy, and p is an integer from 1-6, wherein the alkyl group may be substituted with carboxyl, alkyl, aryl, substituted aryl, heterocyclyl, substituted heterocyclyl, heteroaryl, substituted heteroaryl, hydroxamic acid, sulfonamide, sulfonyl, hydroxy, thiol, alkoxy or arylalkyl;
(d) R 4 is selected from the group consisting of (i) hydrogen, (ii) C 1-3 straight or branched chain alkyl, (iii) benzyl and (iv) —NR 13 R 14 , wherein R 13 and R 14 are independently selected from hydrogen and C 1-6 alkyl; wherein the C 1-3 alkyl and benzyl groups are optionally substituted with one or more groups selected from C 3-7 cycloalkyl, C 1-8 alkoxy, cyano, C 1-4 carboalkoxy, trifluoromethyl, C 1-8 alkylsulfonyl, halogen, nitro, hydroxy, trifluoromethoxy, C 1-8 carboxylate, amino, NR 13 R 14 , aryl and heteroaryl; and (e) X is selected from S and O;
with the proviso that when R 4 is isopropyl, then R 3 is not halogen.
In an alternative embodiment, the invention is directed to compounds of Formula I wherein R 1 , R 3 and R 4 are as described above and R 2 is —NR 15 R 16 wherein R 15 and R 16 are independently selected from hydrogen, optionally substituted C 1-8 straight or branched chain alkyl, arylalkyl, C 3-7 cycloalkyl, aryl, heteroaryl, and heterocyclyl or R 15 and R 16 taken together with the nitrogen form a heteroaryl or heterocyclyl group; with the proviso that when R 2 is NHR 16 R 1 is not —COOR 6 where R 6 is ethyl.
This invention also provides a pharmaceutical composition comprising the instant compound and a pharmaceutically acceptable carrier.
This invention further provides a method of treating a subject having a condition ameliorated by antagonizing Adenosine A2a receptors or by reducing PDE activity in appropriate cells, which comprises administering to the subject a therapeutically effective dose of the instant pharmaceutical composition.
This invention further provides a method of preventing a disorder ameliorated by antagonizing Adenosine A2a receptors or by reducing PDE activity in appropriate cells in a subject, comprising administering to the subject a prophylactically effective dose of the compound of claim 1 either preceding or subsequent to an event anticipated to cause a disorder ameliorated by antagonizing Adenosine A2a receptors or reducing PDE activity in appropriate cells in the subject.
DETAILED DESCRIPTION OF THE INVENTION
Compounds of Formula 1 are potent small molecule antagonists of the Adenosine A2a receptors that have demonstrated potency for the antagonism of Adenosine A2a, A1, and A3 receptors.
Compounds of Formula I are also potent small molecule phosphodiesterase inhibitors that have demonstrated potency for inhibition of PDE7, PD E5, and PDE4. Some of the compounds of this invention are potent small molecule PDE7 inhibitors which have also demonstrated good selectivity against PDE5 and PDE4.
Preferred embodiments for R 1 are COOR 6 , wherein R 6 is selected from H, optionally substituted C 1-8 straight or branched chain alkyl, optionally substituted aryl and optionally substituted arylalkyl. Preferably R 6 is H, or C 1-8 straight or branched chain alkyl which may be optionally substituted with a substituent selected from CN and hydroxy.
Preferred embodiments for R 2 are optionally substituted heterocycle, optionally substituted aryl and optionally substituted heteroaryl. Preferred substituents are from one to three members selected from the group consisting of halogen, alkyl, alkoxy, alkoxyphenyl, halo, triflouromethyl; trifluoro or difluoromethoxy, amino, alkylamino, hydroxy, cyano, and nitro. Preferably, R 2 is optionally substituted furan, phenyl or napthyl or R 2 is
optionally substituted with from one to three members selected from the group consisting of halogen, alkyl, hydroxy, cyano, and nitro. In another embodiment of the instant compound, R 2 is —NR 15 R 16 .
Preferred substituents for R 3 include:
(i) hydrogen, halo, C 1-8 straight or branched chain alkyl, C 1-8 alkoxy, cyano, C 1-4 carboalkoxy, trifluoromethyl, C 1-8 alkylsulfonyl, halogen, nitro, and hydroxy; (ii) —NR 10 R, 11 wherein R 10 and R 11 are independently selected from H, C 1-8 straight or branched chain alkyl, arylC 1-8 alkyl, C 3-7 cycloalkyl, carboxyC 1-8 alkyl, aryl, heteroaryl, and heterocyclyl or R 10 and R 11 , taken together with the nitrogen form a heteroaryl or heterocyclyl group; (iii) —NR 12 COR 13 wherein R 12 is selected from hydrogen or alkyl and R 13 is selected from hydrogen, alkyl, substituted alkyl, C 1-3 alkoxyl, carboxyC 1-8 alkyl, aryl, arylalkyl, R 30 R 31 N (CH 2 ) p —, R 30 R 31 NCO(CH 2 ) p —, heteroaryl and heterocyclyl or R 12 and R 13 taken together with the carbonyl form a carbonyl containing heterocyclyl group, wherein , R 30 and R 31 are independently selected from H, OH, alkyl, and alkoxy, and p is an integer from 1∝6.
Particularly, R 3 is selected from the group consisting of
alkyl(CO)NH—, NH 2 , and NO 2 .
Preferred embodiments for R 4 include hydrogen, C 1-3 straight or branched chain alkyl, particularly methyl, amine and amino.
In a further embodiment of the instant compound, R 1 is COOR 6 and R 2 is selected from the group consisting of substituted phenyl, and substituted naphthyl or R 2 is NR 15 R 16 .
More particularly, R 1 is COOR 6 where R 6 is alkyl, R 2 is substituted phenyl or naphthyl or R 2 is NR 15 R 16 , and R 3 is selected from the group consisting of H, nitro, amino, NHAc, halo, hydroxy, alkoxy, or a moiety of the formulae:
alkyl(CO)NH—, and R 4 is selected from hydrogen, C 1-3 straight or branched chain alkyl, particularly methyl, and amino.
In a preferred embodiment, the compound is selected from the group of compounds shown in Table 1 hereinafter.
More preferably, the compound is selected from the following compounds:
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 2-amino4(1,3-benzodioxol-5yl)-5-oxo-, ethyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(6-bromo-1,3-benzodioxol-5-yl)-2-methyl-5-oxo-, ethyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7-amino4-(1,3 -benzodioxol-5-yl)-2-methyl-5-oxo-, ethyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(6-bromo-1,3-benzodioxol-5-yl)-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-(acetylamino)41,3-benzodioxol-5-yl)-2-methyl-5-oxo-, ethyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 2-methyl4-(3-methylphenyl)5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7-amino-4-(3,5-dimethylphenyl)-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7-amino-2-methyl4-(4-methyl-1-naphthalenyl)-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5dibromo-4-hydroxyphenyl)-2-methyl-8-nitro-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7,8-dichloro-4-(3,5-dibromo-4-hydroxyphenyl)-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 7-bromo(3,5-dibromo-4 -hydroxyphenyl)-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-bromo-4-(3,5-dibromo-4 -hydroxyphenyl)2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-[(3-carboxy-1-oxopropyl)amino]-4-(3,5-dimethylphenyl-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-[(3-carboxy-1-oxopropyl)amino]-2-methyl-4-(4-methyl-1-naphthalenyl)-5oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-8-[[4-(hydroxyamino)-1,4-dioxobutyl]amino]-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5dimethylphenyl)-8[[[(2-hydroxyethyl)amino]acetyl]amino]-2-methyl-5-oxo, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 8-[(4-carboxy-1-oxobutyl)amino]-4-(3,5-dimethylphenyl)-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-8-[[[(2-hydroxyethyl)methylamino]acetyl]amino]-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5dimethylphenyl)-2-methyl-8-[(4-morpholinylacetyl)amino]-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3,5-dimethylphenyl)-2-methyl-5-oxo-8-[(1-piperazinylacetyl)amino]-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-phenyl-2-amino-oxo-, ethyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(4-methylphenyl)-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3-bromophenyl)2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3-bromophenylamino)-2-methyl-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-phenyl-2-amino-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(2-furyl)-2-amino-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(3-furyl)-2-amino-5-oxo-, methyl ester
5H-indeno[1,2-b]pyridine-3-carboxylic acid, 4-(2-furyl)-2-amino-5-oxo-, ethyl ester
The instant compounds can be isolated and used as free bases. They can also be isolated and used as pharmaceutically acceptable salts. Examples of such salts include hydrobromic, hydroiodic, hydrochloric, perchloric, sulfuric, maleic, fumaric, malic, tartaric, citric, benzoic, mandelic, methanesulfonic, hydroethanesulfonic, benzenesulfonic, oxalic, palmoic, 2-naphthalenesulfonic, p-toluenesulfonic, cyclohexanesulfamic and saccharic.
This invention also provides a pharmaceutical composition comprising the instant compound and a pharmaceutically acceptable carrier.
Pharmaceutically acceptable carriers are well known to those skilled In the art and include, but are not limited to, from about 0.01 to about 0.1 M and preferably 0.05 M phosphate buffer or 0.8% saline. Such pharmaceutically acceptable carriers can be aqueous or non-aqueous solutions, suspensions and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, ethanol, alcoholic/aqueous solutions, glycerol, emulsions or suspensions, including saline and buffered media. Oral carriers can be elixirs, syrups, capsules, tablets and the like. The typical solid carrier is an inert substance such as lactose, starch, glucose, methyl-cellulose, magnesium stearate, dicalcium phosphate, mannitol and the like. Parenteral carriers include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's and fixed oils. Intravenous carriers include fluid and nutrient replenishers, electrolyte replenishers such as those based on Ringer's dextrose and the like. Preservatives and other additives can also be present, such as, for example, antimicrobials, antioxidants, chelating agents, inert gases and the like. All carriers can be mixed as needed with disintegrants, diluents, granulating agents, lubricants, binders and the like using conventional techniques known in the art.
This invention further provides a method of treating a subject having a condition ameliorated by antagonizing Adenosine A2a receptors or by reducing PDE activity in appropriate cells, which comprises administering to the subject a therapeutically effective dose of the instant pharmaceutical composition.
In one embodiment, the disorder is a neurodegenerative or movement disorder. In another embodiment, the disorder is an inflammatory disorder. In still another embodiment, the disorder is an AIDS-related disorder. Examples of disorders treatable by the instant pharmaceutical composition include, without limitation, Parkinson's Disease, Huntington's Disease, Multiple System Atrophy, Corticobasal Degeneration, Alzheimer's Disease, Senile Dementia, organ transplantation, autoimmune disorders (e.g. arthritis), immune challenge such as a bee sting, inflammatory bowel disease, bronchial disorders (e.g. asthma), HIV/AIDS, cardiovascular disorder, erectile dysfunction, allergies, and psoriasis.
In one preferred embodiment, the disorder is rheumatoid arthritis.
In another preferred embodiment, the disorder is Parkinson's disease.
As used herein, the term “subject” includes, without limitation, any animal or artificially modified animal having a disorder ameliorated by reducing PDE activity in appropriate cells. In a preferred embodiment, the subject is a human. In a more preferred embodiment, the subject is a human,
As used herein, “appropriate cells” include, by way of example, cells which display PDE activity. Specific examples of appropriate cells include, without limitation, T-lymphocytes, muscle cells, neuro cells, adipose tissue cells, monocytes, macrophages, fibroblasts.
Administering the instant pharmaceutical composition can be effected or performed using any of the various methods known to those skilled in the art. The instant compounds can be administered, for example, intravenously, intramuscularly, orally and subcutaneously. In the preferred embodiment, the instant pharmaceutical composition is administered orally. Additionally, administration can comprise giving the subject a plurality of dosages over a suitable period of time. Such administration regimens can be determined according to routine methods.
As used herein, a “therapeutically effective dose” of a pharmaceutical composition is an amount sufficient to stop, reverse or reduce the progression of a disorder. A “prophylactically effective dose” of a pharmaceutical composition is an amount sufficient to prevent a disorder, i.e., eliminate, ameliorate and/or delay the disorder's onset. Methods are known in the art for determining therapeutically and prophylactically effective doses for the instant pharmaceutical composition. The effective dose for administering the pharmaceutical composition to a human, for example, can be determined mathematically from the results of animal studies.
In one embodiment, the therapeutically and/or prophylactically effective dose is a dose sufficient to deliver from about 0.001 mg/kg of body weight to about 200 mg/kg of body weight of the instant pharmaceutical composition. In another embodiment, the therapeutically and/or prophylactically effective dose is a dose sufficient to deliver from about 0.05 mg/kg of body weight to about 50 mg/kg of body weight. More specifically, in one embodiment, oral doses range from about 0.05 mg/kg to about 100 mg/kg daily. In another embodiment, oral doses range from about 0.05 mg/kg to about 50 mg/kg daily, and in a further embodiment, from about 0.05 mg/kg to about 20 mg/kg daily. In yet another embodiment, infusion doses range from about 1.0 μg/kg/min to about 10 mg/kg/min of inhibitor, admixed with a pharmaceutical carrier over a period ranging from about several minutes to about several days. In a further embodiment, for topical administration, the instant compound can be combined with a pharmaceutical carrier at a drug/carrier ratio of from about 0.001 to about 0.1.
This invention still further provides a method of preventing an inflammatory response in a subject, comprising administering to the subject a prophylactically effective amount of the instant pharmaceutical composition either preceding or subsequent to an event anticipated to cause the inflammatory response in the subject. In the preferred embodiment, the event is an insect sting or an animal bite.
Definitions and Nomenclature
Unless otherwise noted, under standard nomenclature used throughout this disclosure the terminal portion of the designated side chain is described first, followed by the adjacent functionality toward the point of attachment.
As used herein, the following chemical terms shall have the meanings as set forth in the following paragraphs: “independently”, when in reference to chemical substituents, shall mean that when more than one substituent exists, the substituents may be the same or different;.
“Alkyl” shall mean straight, cyclic and branched-chain alkyl. Unless otherwise stated, the alkyl group will contain 1-20 carbon atoms. Unless otherwise stated, the alkyl group may be optionally substituted with one or more groups such as halogen, OH, CN, mercapto, nitro, amino, C 1 -C 8 -alkyl, C 1 -C 8 -alkoxyl, C 1 -C 8 -alkylthio, C 1 -C 8 -alkyl-amino, di(C 1 -C 8 -alkyl)amino, (mono-, di-, tri-, and per-) halo-alkyl, formyl, carboxy, alkoxycarbonyl, C 1 -C 8 -alkyl-CO—O—, C 1 -C 8 -alkyl-CO—NH—, carboxamide, hydroxamic acid, sulfonamide, sulfonyl, thiol, aryl, aryl(c 1 -c 8 )alkyl, heterocyclyl, and heteroaryl.
“Alkoxy” shall mean —O-alkyl and unless otherwise stated, it will have 1-8 carbon atoms.
The term “bioisostere ” is defined as “groups or molecules which have chemical and physical properties producing broadly similar biological properties.” (Burger's Medicinal Chemistry and Drug Discovery, M. E. Wolff, ed. Fifth Edition, Vol. 1, 1995, Pg. 785).
“Halogen” shall mean fluorine, chlorine, bromine or iodine; “PH” or “Ph” shall mean phenyl; “Ac” shall mean acyl; “Bn” shall mean benzyl.
The term “acyl” as used herein, whether used alone or as part of a substituent group, means an organic radical having 2 to 6 carbon atoms (branched or straight chain) derived from an organic acid by removal of the hydroxyl group. The term “Ac” as used herein, whether used alone or as part of a substituent group, means acetyl.
“Aryl” or “Ar,” whether used alone or as part of a substituent group, is a carbocyclic aromatic radical Including, but not limited to, phenyl, 1- or 2-naphthyl and the like. The carbocyclic aromatic radical may be substituted by independent replacement of 1 to 5 of the hydrogen atoms thereon with halogen, OH, CN, mercapto, nitro, amino, C 1 -C 8 -alkyl, C 1 -C 8 -alkoxyl, C 1 -C 8 -alkylthio, C 1 -C 8 -alkyl-amino, di(C 1 -C 8 -alkyl)amino, (mono-, di-, tri-, and per-) halo-alkyl, formyl, carboxy, alkoxycarbonyl, C 1 -C 8 -alkyl-CO—O—, C 1 -C 8 -alkyl-CO—NH—, or carboxamide. Illustrative aryl radicals include, for example, phenyl, naphthyl, biphenyl, fluorophenyl, difluorophenyl, benzyl, benzoyloxyphenyl, carboethoxyphenyl, acetylphenyl, ethoxyphenyl, phenoxyphenyl, hydroxyphenyl, carboxyphenyl, trifluoromethylphenyl, methoxyethylphenyl, acetamidophenyl, tolyl, xylyl, dimethylcarbamylphenyl and the like. “Ph” or “PH” denotes phenyl.
Whether used alone or as part of a substituent group, “heteroaryl” refers to a cyclic, fully unsaturated radical having from five to ten ring atoms of which one ring atom is selected from S, O, and N; 0-2 ring atoms are additional heteroatoms independently selected from S, O, and N; and the remaining ring atoms are carbon. The radical may be joined to the rest of the molecule via any of the ring atoms. Exemplary heteroaryl groups include, for example, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyrroyl, pyrazolyl, imidazolyl , thiazolyl, oxazolyl, isoxazolyl, thiadiazolyl, triazolyl, triazinyl, oxadiazolyl, thienyl, furanyl, quinolinyl, isoquinolinyl, indolyl, isothiazolyl, 2-oxazepinyl, azepinyl, N-oxo-pyridyl, 1-dioxothienyl, benzothiazolyl, benzoxazolyl, benzothienyl, quinolinyl-N-oxide, benzimidazolyl, benzopyranyl, benzisothiazolyl, benzisoxazolyl, benzodiazinyl, benzofurazanyl, benzothiopyranyl, indazolyl, indolizinyl, benzofuryl, chromonyl, coumarinyl, cinnolinyl, quinoxalinyl, indazolyl, pyrrolopyridinyl, furopyridinyl (such as furo[2,3-c]pyridinyl, furo[3,2-b]pyridinyl, or furo[2,3-b]pyridinyl), imidazopyridinyl (such as imidazo[4,5-b]pyridinyl or imidazo[4,5-c]pyridinyl), naphthyridinyl, phthalazinyl, purinyl, pyridopyridyl, quinazolinyl, thienofuryl, thienopyridyl, thienothienyl, and furyl. The heteroaryl group may be substituted by independent replacement of 1 to 5 of the hydrogen atoms thereon with halogen, OH, CN, mercapto, nitro, amino, C 1 -C 8 -alkyl, C 1 -C 8 -alkoxyl, C 1 -C 8 -alkylthio, C 1 -C 8 -alkyl-amino, di(C 1 -C 8 -alkyl)amino, (mono-, di-, tri-, and per-) halo-alkyl, formyl, carboxy, alkoxycarbonyl, C 1 -C 8 -alkyl-CO—O—, C 1 -C 8 -alkyl-CO—NH—, or carboxamide. Heteroaryl may be substituted with a mono-oxo to give for example a 4-oxo-1H-quinoline.
The terms “heterocycle,” “heterocyclic,” and “heterocycle” refer to an optionally substituted, fully or partially saturated cyclic group which is, for example, a 4- to 7-membered monocyclic, 7- to 11-membered bicyclic, or 10- to 15-membered tricyclic ring system, which has at least one heteroatom in at least one carbon atom containing ring. Each ring of the heterocyclic group containing a heteroatom may have 1, 2, or 3 heteroatoms selected from nitrogen atoms, oxygen atoms, and sulfur atoms, where the nitrogen and sulfur heteroatoms may also optionally be oxidized. The nitrogen atoms may optionally be quaternized. The heterocyclic group may be attached at any heteroatom or carbon atom.
Exemplary monocyclic heterocyclic groups include pyrrolidinyl; oxetanyl; pyrazolinyl; imidazolinyl; imidazolidinyl; oxazolyl; oxazolidinyl; isoxazolinyl; thiazolidinyl; isothiazolidinyl; tetrahydrofuryl; piperidinyl; piperazinyl; 2-oxopiperazinyl; 2-oxopiperidinyl; 2-oxopyrrolidinyl; 4-piperidonyl; tetrahydropyranyl; tetrahydrothiopyranyl; tetrahydrothiopyranyl sulfone; morpholinyl; thiomorpholinyl; thiomorpholinyl sulfoxide; thiomorpholinyl sulfone; 1,3-dioxolane; dioxanyl; thietanyl; thiiranyl; and the like. Exemplary bicyclic heterocyclic groups include quinuclidinyl; tetrahydroisoquinolinyl; dihydroisoindolyl; dihydroquinazolinyl (such as 3,4-dihydro-4-oxo-quinazolinyl); dihydrobenzofuryl; dihydrobenzothienyl; dihydrobenzothiopyranyl; dihydrobenzothiopyranyl sulfone; dihydrobenzopyranyl; indolinyl; isochromanyl; isoindolinyl; piperonyl; tetrahydroquinolinyl; and the like.
Substituted aryl, substituted heteroaryl, and substituted heterocycle may also be substituted with a second substituted-aryl, a second substituted-heteroaryl, or a second substituted-heterocycle to give, for example, a 4-pyrazol-1-yl-phenyl or 4-pyridin-2-yl-phenyl.
Designated numbers of carbon atoms (e.g., C 1-8 ) shall refer independently to the number of carbon atoms in an alkyl or cycloalkyl moiety or to the alkyl portion of a larger substituent in which alkyl appears as its prefix root.
Unless specified otherwise, it is intended that the definition of any substituent or variable at a particular location in a molecule be independent of its definitions elsewhere in that molecule. It is understood that substituents and substitution patterns on the compounds of this invention can be selected by one of ordinary skill in the art to provide compounds that are chemically stable and that can be readily synthesized by techniques known in the art as well as those methods set forth herein.
Where the compounds according to this invention have at least one stereogenic center, they may accordingly exist as enantiomers. Where the compounds possess two or more stereogenic centers, they may additionally exist as diastereomers. Furthermore, some of the crystalline forms for the compounds may exist as polymorphs and as such are intended to be included in the present invention. In addition, some of the compounds may form solvates with water (i.e., hydrates) or common organic solvents, and such solvates are also intended to be encompassed within the scope of this invention.
Some of the compounds of the present invention may have trans and cis isomers. In addition, where the processes for the preparation of the compounds according to the invention give rise to mixture of stereoisomers, these isomers may be separated by conventional techniques such as preparative chromatography. The compounds may be prepared as a single stereoisomer or in racemic form as a mixture of some possible stereoisomers. The non-racemic forms may be obtained by either synthesis or resolution. The compounds may, for example, be resolved into their components enantiomers by standard techniques, such as the formation of diastereomeric pairs by salt formation. The compounds may also be resolved by covalent linkage to a chiral auxiliary, followed by chromatographic separation and/or crystallographic separation, and removal of the chiral auxiliary. Alternatively, the compounds may be resolved using chiral chromatography.
This invention will be better understood by reference to the Experimental Details which follow, but those skilled in the art will readily appreciate that these are only illustrative of the invention as described more fully in the claims which follow thereafter. Additionally, throughout this application, various publications are cited. The disclosure of these publications is hereby incorporated by reference into this application to describe more fully the state of the art to which this invention pertains.
Experimental Details
I. General Synthetic Schemes
Representative compounds of the present invention can be synthesized in accordance with the general synthetic methods described below and illustrated in the following general schemes. The products of some schemes can be used as intermediates to produce more than one of the instant compounds. The choice of intermediates to be used to produce subsequent compounds of the present invention is a matter of discretion that is well within the capabilities of those skilled in the art.
Procedures described in Scheme 1, wherein R 3a , R 3b , R 3c , and R 3d are independently any R 3 group, and R 1 , R 2 , R 3 , and R 4 are as described above, can be used to prepare compounds of the invention wherein X is O.
Benzylidenes 2 may be obtained by known methods (Bullington, J. L; Cameron, J. C.; Davis, J. E.; Dodd, J. H.; Harris, C. A.; Henry, J. R.; Pellegrino-Gensey, J. L.; Rupert, K. C.; Siekierka, J. J. Bioorg. Med. Chem. Lett. 1998, 8, 2489; Petrow, V.; Saper, J.; Sturgeon, B. J. Chem. Soc. 1949, 2134). Hantzsch reaction of the benzylidene compounds with enamines 3 can be performed in refluxing acetic acid (Petrow et al., supra). When the desired enamines are not available, alternate Hantzsch conditions may be utilized which involve adding ammonium acetate to the reaction. The resulting dihydropyridines 4 are oxidized with chromium trioxide to obtain the desired pyridines 1 (Petrow et al., supra). In cases where the substitution pattern on the fused aromatic ring (R 3 ) leads to a mixture of regioisomers, the products can be separated by column chromatography.
In some cases, especially where R 2 is an alkyl group, another modification of the Hantzsch may be performed which uses three components (Bocker, R. H.; Buengerich, P. J. Med. Chem. 1986, 29, 1596). Where R 2 is an alkyl group it is also necessary to perform the oxidation with DDQ or MnO 2 instead of chromium (VI) oxide (Vanden Eynde, J. J.; Delfosse, F.; Mayence, A.; Van Haverbeke, Y. Tetrahedron 1995, 51, 6511).
In order to obtain the corresponding carboxylic acids and amides, the cyanoethyl esters 5 are prepared as described above. The esters are converted to the carboxylic acids by treatment with sodium hydroxide in acetone and water (Ogawa, T.; Matsumoto, K.; Yokoo, C.; Hatayama, K.; Kitamura, K. J. Chem. Soc., Perkin Trans. 1 1993, 525). The corresponding amides can then be obtained from the acids using standard means.
The procedure for making compounds where R 4 is NH 2 may be slightly modified. These compounds are prepared in one step from the benzylidenes 2 and alkyl amidinoacetate (Kobayashi, T.; Inoue, T.; Kita, Z.; Yoshiya, H.; Nishino, S.; Oizumi, K.; Kimura, T. Chem. Pharm. Bull. 1995, 43, 788) as depicted in Scheme 4 wherein R is R 5 or R 6 as described above.
The dihydropyridine lactones 9 can be synthesized from benzylidenes 8 (Zimmer, H.; Hillstrom, W. W.; Schmidt, J. C.; Seemuth, P. D.; Vogeli, R. J. Org. Chem. 1978, 43, 1541) and 1,3-indanedione, as shown in Scheme 5, and the corresponding pyridine is then obtained by oxidation with manganese dioxide.
Representative schemes to modify substituents on the fused aromatic ring are shown below. The amines 11 are obtained from the corresponding nitro compounds 10 by reduction with tin (II) chloride (Scheme 6). Reaction of the amines with acetyl chloride provide the amides 12.
In accordance with Scheme 7 wherein Y is 0, and n is an integer from 1-3, an alkyl chain with a carboxylic acid at the terminal end can also be added to the amines 11. For example, reaction with either succinic anhydrid (Omuaru, V. O. T.; Indian J. Chem., Sect B. 1998, 37, 814) or β-propiolactone (Bradley, G.; Clark, J.; Kernick, W. J. Chem. Soc., Perkin Trans. 1 1972, 2019) can provide the corresponding carboxylic acids 13. These carboxylic acids are then converted to the hydroxamic acids 14 by treatment with ethyl chloroformate and hydroxylamin (Reddy, A. S.; Kumar, M. S.; Reddy, G. R. Tetrahedron Lett. 2000, 41, 6285).
The amines 11 can also be treated with glycolic acid to afford alcohols 15 (Jursic, B. S.; Zdravkovski, Z. Synthetic Comm. 1993,23, 2761) as shown in Scheme 8.
As shown in Scheme 9, the aminoindenopyridines 11 may also be treated with chloroacetylchloride followed by amines to provide the more elaborate amines 16 (Weissman, S. A.; Lewis, S.; Askin, D.; Volante, R. P.; Reider, P. J. Tetrahedron Led. 1998, 39,7459). Where R 6 is a hydroxyethyl group, the compounds can be further converted to piperazinones 17.
The 4-aminoindenopyridines 19 can be synthesized from the 4-chloroindenopyridines 18 using a known procedure (Gorlitzer, K.; Herbig, S.; Walter, R. D. Pharmazie 1997, 504) or via palladium catalyzed coupling (Scheme 10).
Cyanoesters 20 can be prepared by known methods (Lee, J.; Gauthier, D.; Rivero, R. A. J. Org. Chem. 1999, 64, 3060). Reaction of 20 with enaminone 21 (lida, H.; Yuasa, Y.; Kibayashi, C. J. Org. Chem. 1979, 44, 1074) in refluxing 1-propanol and triethylamine gave dihydropyridine 22, wherein R is R 5 or R 6 as described above, (Youssif, S.; El-Bahaie, S.; Nabih, E. J. Chem. Res. (S) 1999, 112 and Bhuyan, P.; Borush, R. C.; Sandhu, J. S. J. Org. Chem. 1990, 55, 568), which can then be oxidized and subsequently deprotected to give pyridine 23.
II. Specific Compound Syntheses
Specific compounds which are representative of this invention can be prepared as per the following examples. No attempt has been made to optimize the yields obtained in these reactions. Based on the following, however, one skilled in the art would know how to increase yields through routine variations in reaction times, temperatures, solvents and/or reagents.
The products of certain syntheses can be used as intermediates to produce more than one of the instant compounds. In those cases, the choice of intermediates to be used to produce compounds of the present invention is a matter of discretion that is well within the capabilities of those skilled in the art.
EXAMPLE 1
Hantzsch Condensation to Form Dihydropyridine 4 (R 1 =COOMe; R 2 =3,5-dimethylphenyl; R 3b,c =Cl; R 3a,b =H; R 4 =Me)
To a refluxing solution of benzylidene 2 (0.500 g, 1.5 mmol) in acetic acid (10 mL) was added methyl-3-aminocrotonate (0.695 g, 6.0 mmol). The reaction was heated to reflux for 20 minutes, then water was added until a precipitate started to form. The reaction was cooled to room temperature. The mixture was filtered and washed with water to obtain 0.354 g (55%) of a red solid. MS m/z 450 (M + +23), 428 (M + +1).
EXAMPLE 2
Alternate Hantzsch Conditions to Form Dihydropyridine 4 (R 1 =CO 2 Me; R 2 =2,4-dimethylphenyl; R 3 =H; R 4 =Et)
To a refluxing solution of benzylidene 2 (1.00 g, 3.82 mmol) in acetic acid (12 Ml) was added methyl propionylacetate (1.98 g, 15.2 mmol) and ammonium acetate (1.17 g, 15.2 mmol). The reaction was heated for 20 min and then cooled to room temperature. No product precipitated from the solution, so the reaction was heated to reflux and then water was added until a solid began to precipitate. After cooling to room temperature, the mixture was filtered and the red solid washed with water to yield 1.29 g (90%) of product. MS m/z 396 (M + +23), 374 (M + +1).
EXAMPLE 3
Oxidation of Dihydropyridine 4 to Pyridine 1 (R 1 =COOMe; R 2 =3,5-dimethylphenyl; R 3a,b =Cl; R 3a,d =H; R 4 =Me)
To a refluxing solution of dihydropyridine 4 (0.250 g, 0.58 mmol) in acetic acid (10 mL) was added a solution of chromium (VI) oxide (0.584 g, 0.58 mmol) in 1 mL water. After 30 minutes at reflux, the reaction was diluted with water until a precipitate started to form. The mixture was cooled to room temperature and allowed to stand overnight. The mixture was filtered and washed with water to give 0.199 g (81%) of a yellow solid. MS m/z 448 (M + +23), 426 (M + +1).
EXAMPLE 4
Oxidation of Dihydropyridine 4 to Pyridine 1 (R 1 =COOMe; R 2 =(4-methyl)-1-naphthyl; R 3b,c =H, NO 2 /NO 2 , H; R=Me)
To a refluxing suspension of regioisomeric dihydropyridines 4 (3.59 g, 8.16 mmol) in acetic acid (40 mL) was added a solution of chromium (VI) oxide (0.816 g, 8.16 mmol) in 3 mL water. After 20 minutes at reflux, the reaction was diluted with water until a precipitate started to form. The mixture was cooled to room temperature and allowed to stand overnight. The mixture was filtered and washed with water to yield the mixture of regioisomers as a yellow solid. The products were purified by column chromatography eluting with hexanes:ethyl acetate to yield 1.303 g (37%) of pyridine 1 (R 3b =NO 2 ; R 3c =H) and 0.765 g (21%) of its regioisomer (R 3b =H; R 3c =N0 2 ). MS m/z 461 (M + +23), 439 (M + +1).
EXAMPLE 5
Alternate Three Component Hantzsch Reaction to Form Dihydropyridine 4 (R 1 =CO 2 Me; R 2 =cyclohexyl; R 3 =H; R 4 =Me)
Cyclohexane carboxaldehyde (2.0 g, 17.8 mmol), 1,3-indandione (2.6 g, 17.8 mmol), methylacetoacetate (2.0 g, 17.8 mmol), and ammonium hydroxide (1 mL) were refluxed in 8 mL of methanol for 1.5 hours. The temperature was lowered to approximately 50° C. and the reaction was stirred overnight. The reaction was cooled to room temperature, filtered and the solid washed with water. The residue was then dissolved in hot ethanol and filtered while hot. The filtrate was concentrated to yield 4.1 g (68%) of the product which was used without purification. MS m/z 336 (M − −1).
EXAMPLE 6
DDQ Oxidation of Dihydropyridine 4 (R 1 =CO 2 Me; R 2 =cyclohexyl: R 3 =H; R 4 =Me)
To a solution of dihydropyridine 4 (2.50 g, 7.40 mmol) in 15 mL of dichloromethane was added 2,3-dichloro-3,6-dicyano-1,4-benzoquinone (1.70 g, 7.40 mmol). The reaction was stirred at room temperature for four hours. The mixture was filtered and the residue was washed with dichloromethane. After the filtrate was concentrated, the residue was purified by column chromatography eluting with ethyl acetate: hexanes to yield 0.565 g (23%) of a yellow solid. MS m/z 358 (M + +23), 336 (M + +1).
EXAMPLE 7
MnO 2 Oxidation of Dihydropyridine 4 (R 1 =CO 2 Me; R 2 =4-(dimethylamino)phenyl: R 3 =H; R 4 =Me)
To a solution of dihydropyridine 4 (0.50 g, 1.3 mmol) in 10 mL of dichloromethane was added manganese dioxide (2.5 g, 28.7 mmol). The reaction was stirred at room temperature overnight before filtering and washing with dichloromethane. The filtrate was concentrated to yield 0.43 g (88%) of orange solid 1. MS m/z 395 (M + +23), 373 (M + +1).
EXAMPLE 8
Cleavage of Carboxylic Ester 5 (R 2 =2,4-dimethylphenyl; R 3 =H; R 4 =Me)
To a suspension of ester 5 (2.75 g, 6.94 mmol) in acetone (50 mL) was added aqueous 1 M NaOH (100 mL). After stirring at room temperature for 24 hours, the reaction mixture was diluted with 100 mL of water and washed with dichloromethane (2×100 mL). The aqueous layer was cooled to 0° C. and acidified with concentrated HCl. The mixture was filtered and washed with water to yield 1.84 g (77%) yellow solid 6. MS m/z 366 (M + +23), 343 (M + +1).
EXAMPLE 9
Preparation of Amide 7 (R 2 =2.4-dimethylphenyl; R 3 =H; R 4 =Me; R 5 =H; R 6 =Me)
A solution of carboxylic acid 6 (0.337 g, 0.98 mmol) in thionyl chloride (10 mL) was heated at reflux for 1 hour. The solution was cooled and concentrated in vacuo. The residue was diluted with CCl 4 and concentrated to remove the residual thionyl chloride. The residue was then dissolved in THF (3.5 mL) and added to a 0° C. solution of methylamine (1.47 mL of 2.0 M solution in THF, 2.94 mmol) in 6.5 mL THF. The reaction was warmed to room temperature and stirred overnight. The mixture was poured into water, filtered, washed with water and dried to yield 0.263 g (75%) of tan solid. MS m/z 357(M + +1).
EXAMPLE 10
Preparation of Pyridine 1 (R 1 =CO 2 Et: R 2 =4-nitrophenyl; R 3 =H; R 4 =NH 2 )
To a refluxing solution of benzylidene 2 (1.05 g, 3.76 mmol) in 10 mL of acetic acid was added ethyl amidinoacetate acetic acid salt (0.720 g. 3.76 mmol). The resulting solution was heated at reflux overnight. After cooling to room temperature, the resulting precipitate was removed by filtration and washed with water. This impure residue was heated in a minimal amount of ethanol and then filtered to yield 0.527 g (35%) of a yellow solid. MS m/z 412 (M + +23), 390 (M + +1).
EXAMPLE 11
Hantzsch Condensation of Benzylidene 8 (R 2 =3-methoxyphenyl) and 1,3-indandione)
The benzylidene 8 (2.00 g, 9.2 mmol), 1,3-indandione (1.34 g, 0.2 mmmol) and ammonium acetate (2.83 g, 36.7 mmol) were added to 30 mL of ethanol and heated to reflux overnight. The reaction mixture was cooled to room temperature and diluted with ethanol. A yellow precipitate was collected by filtration, washed with ethanol, and dried under vacuum to yield 1.98 g (63%) of the dihydropyridine 9. MS m/z 346 (M + +1).
EXAMPLE 12
Reduction to Prepare Amine 11 (R 1 =CO 2 Me; R 2 =4-methylnaphthyl; R 4 =Me)
To a refluxing suspension of pyridine 10 (0.862 g, 1.97 mmol) in 35 mL of ethanol was added a solution of tin (II) chloride dihydrate (1.33 g, 5.90 mmol) in 6 mL of 1:1 ethanol: concentrated HCl. The resulting solution was heated at reflux overnight. Water was added until a precipitate started to form and the reaction was cooled to room temperature. The mixture was then filtered and washed with water. After drying, the residue was purified by column chromatography eluting with hexanes: ethyl acetate to yield 0.551 g (69%) of an orange solid. MS m/z 431 (Me + +23), 409 (M + +1).
EXAMPLE 13
Acetylation of Amine 11 (R 1 =CO 2 Et; R 2 =3,4-methylenedioxyphenyl; R 4 =Me)
To a solution of amine 11 (0.070 g, 0.174 mmol) in 15 mL of dichloromethane was added triethylamine (0.026 g, 0.261 mmol) and acetyl chloride (0.015 g, 0.192 mmol). After stirring overnight at room temperature, the reaction mixture was diluted with water and then extracted with dichloromethane (3×35 mL). The combined organics were washed with brine, dried over MgSO 4 , and concentrated. The residue was purified by silica gel chromatography eluting with hexanes: ethyl acetate to yield 0.054 g (70%) of amide 12. MS m/z 467 (M + +23), 445 (M + +1).
EXAMPLE 14
Preparation of Carboxylic Acid 13 (R 1 =CO 2 Me; R 2 =3,5dimethylphenyl; R 4 =Me; Y=O; n=2)
To a suspension of amine 11 (0.079 g, 0.212 mmol) in 5 mL of benzene was added succinic anhydride (0.021 g, 0.212 mmol). After heating at reflux for 24 hours, the reaction mixture was filtered and washed with benzene. The residue was dried under high vacuum and then washed with ether to remove the excess succinic anhydride. This yielded 0.063 g (63%) of carboxylic acid 13. MS m/z 473 (M + +1).
EXAMPLE 15
Preparation of Carboxylic Acid 13 (R 1 =CO 2 Me; R 2 =3,5-dimethylphenyl: R 4 =Me; Y=H 2 : n=1)
To a refluxing solution of amine 11 (0.078 g, 0.210 mmol) in 5 mL of acetonitrile was added β-propiolactone (0.015 g, 0.210 mmol). The reaction was heated to reflux for 72 hours before cooling to room temperature. The reaction mixture was concentrated. The residue was mixed with 10% aqueous sodium hydroxide and washed sequentially with ether and ethyl acetate. The aqueous layer was acidified with concentrated HCl and extracted with dichloromethane (2×25 mL). The combined organics were dried over MgSO 4 , filtered, and concentrated. The residue was purified by column chromatography eluting with 5% MeOH in dichloromethane to yield 0.020 g (21%) of an orange solid. MS m/z 467 (M + +23), 445 (M + +1).
EXAMPLE 16
Preparation of Hydroxamic Acid 14 (R 1 =CO 2 Me; R 2 =(4-methyl)-1-naphthyl: Y=O; n=2; R 4 =Me)
To a 0° C. suspension of carboxylic acid 13 (0.054 g, 0.106 mmmol) in 10 mL of diethyl ether was added triethylamine (0.014 g, 0.138 mmol) and then ethyl chloroformate (0.014 g, 0.127 mmol). The mixture was stirred at 0° C. for 30 minutes and them warmed to room temperature. A solution of hydroxylamine (0.159 mmol) in methanol was added and the reaction was stirred overnight at room temperature. The mixture was filtered and the residue was washed with ether and dried under vacuum to yield 0.030 g (54%) of a yellow solid. MS m/z 524 (M + +1).
EXAMPLE 17
Preparation of Amide 15 (R 1 =CO 2 Me; R 2 =3,5-dimethylphenyl: R 4 =Me)
A mixture of amine 11 (0.201 g, 0.54 mmol) and glycolic acid (0.049 g, 0.65 mmol) was heated at 120-160° C. for 30 minutes. During heating, more glycolic acid was added to ensure that excess reagent was present. Once the starting material was consumed, the reaction was cooled to room temperature, and diluted with dichloromethane. The resulting mixture was extracted with 20% NaOH, followed by 10% HCl, and finally water. The combined organics were concentrated and triturated with ether. Purification by column chromatography eluting with ethyl acetate: hexanes yielded 0.012 g, (5%) of a yellow solid. MS m/z453 (M + +23), 431 (M + +1).
EXAMPLE 18
Preparation of Amide 16 (R 1 =CO 2 Me; R 2 =3,5-dimethylphenyl; R 4 =Me; NR 6 R 7 =morpholino)
To a 0° C. mixture of amine 11 (0.123 g, 0.331 mmol) in 2 mL of 20% a aqueous NaHCO 3 and 3 mL of ethyl acetate was added chloroacetyl chloride (0.047 g, 0.413 mmol). The reaction was warmed to room temperature and stirred for 45 minutes. The mixture was poured into a separatory funnel and the aqueous layer was removed. The organic layer containing the crude chloroamide was used without purification. To the ethyl acetate solution was added morpholine (0.086 g, 0.992 mmol) and the reaction was heated to approx. 65° C. overnight. The reaction was diluted with water and cooled to room temperature. After extraction with ethyl acetate (3×25 mL), the combined organics were washed with brine, dried over MgSO 4 and concentrated to yield 0.130 g (79%) of a yellow solid. MS m/z 522 (M + +23), 500 (M + +1).
EXAMPLE 19
Preparation of piperazinone 17 (R 1 =CO 2 Me; R 2 =3,5-dimethylphenyl; R 4 =Me; R 7 =H)
To a 0° C. solution of amide 16 (R 6 =CH 2 CH 2 OH) (0.093 g, 0.20 mmol), tri n-butylphosphine (0.055 g, 0.27 mmol) in 0.35 mL ethyl acetate was slowly added di-tert-butyl azodicarboxylate (0.062 g, 0.27 mmol) in 0.20 mL ethyl acetate. The reaction was allowed to stand for 15 minutes and then heated to 40° C. overnight. 4.2 M ethanolic HCl was added dropwise. The mixture was cooled to 0° C. and allowed to stand for 2 hours. The mixture was filtered and washed with cold ethyl acetate. Purification by column chromatography with 1-5% MeOH in CH 2 Cl 2 yielded 0.011 (12%) of a white solid. MS m/z 478 (M + +23), 456 (M + +1).
EXAMPLE 20
Preparation of 4-Aminoindenopyridine 19 (R 1 =CO 2 Me; R 4 =Me; R 6 =Me; R 7 =phenyl)
To a solution of 4-chloroindenopyridine 18 (0.069 g, 0.240 mmol) in 10 mL of 2-ethoxyethanol was added N-methylaniline (0.026 g, 0.240 mmol). The reaction was heated at reflux for 96 hours. After cooling to room temperature, the solution was concentrated. The residue was purified by column chromatography eluting with hexanes: ethyl acetate to yield 0.029 g (34%) of an orange solid. MS m/z 359 (M + +1).
EXAMPLE 21
Preparation of 4-Aminoindenopyridine 19 (R 1 =CO 2 Me; R 4 =Me; R 6 =H; R 7 =cyclopentyl) by Palladium Catalyzed Coupling
A mixture of 4-chloroindenopyridine 18 (0.100 g, 0.347 mmol), cyclopentylamine (0.035 g, 0.416 mmol), palladium (II) acetate (0.004 g, 0.0017 mmol), 2-(di-t-butylphosphino)biphenyl (0.010 g, 0.0035 mmol), and cesium carbonate (0.124 g, 0.382 mmol) in 10 mL of dioxane was heated at reflux overnight. The reaction was cooled to room temperature, diluted with water, and extracted with ethyl acetate (3×35 mL). The combined organics were washed with brine, dried over Na 2 SO 4 , and concentrated. The residue was purified by column chromatography eluting with ethyl acetate: hexanes. The purified oil was dissolved in ether and cooled to 0° C. To this solution was slowly added 1.0 M HCl in ether. The resulting precipitate was isolated by filtration, washed with ether, and dried under vacuum to yield 0.032 g (25%) of a yellow solid. MS m/z 359 (M + +23), 337 (M + +1).
EXAMPLE 22
Preparation of Dihydropyridine 21 (R 1 =CO 2 Me; R 2 =2-furyl; R 3 =H; R 4 =NH 2 )
Unsaturated cyanoester 20 (0.20g, 1.10 mmol), enamine 21 (0.20g, 0.75 mmol) and 5 drops of triethylamine were refluxed in 1-propanol (4 mL). After 3 hours, the reaction was concentrated to half the volume and cooled. The resulting precipitate was filtered and washed with 1-propanol. The precipitate was a mixture of products and therefore was combined with the filtrate and concentrated. Purification by column chromatography, eluting with ethyl acetate: hexane yielded 0.11 g (34%) of the red product 22. MS m/z465 (M + +23).
EXAMPLE 23
DDQ Oxidation/Deprotection of Dihydropyridine 22 (R 1 =CO 2 Me; R 2 =3-furyl; R 3 =H; R 4 =NH 2 )
To a solution of dihydropyridine 22(0.05 g, 0.11 mmol) in chlorobenzene (4 mL) was added 2,3-dichloro-3,6-dicyano-1,4-benzoquinone (0.05g, 0.22 mmol). The reaction was refluxed overnight before cooling to room temperature and diluting with diethyl ether. The reaction mixture was filtered through celite and concentrated in vacuo. Purification by column chromatography, eluting with ethyl acetate:hexane yielded 0.018 g (52%) of yellow product 23. MS m/z 343 (M + +23), 321 (M + +1).
Following the general synthetic procedures outlined above and in Examples 1-21, the compounds of Table 1 below were prepared.
TABLE 1 Ia MS No. R 1 R 2 R 3a R 3b R 3c R 3d R 4 (M + 1) 1 CN H H H H Me 341 2 CO 2 Et H H H H Me 388 3 CO 2 t-Bu H H H H Me 416 4 CO 2 t-Bu H H H H Me 432 5 CO 2 Et H H H H Me 389 6 CO 2 H H H H H Me 360 7 CO 2 Et H H H H Me 480 8 CO 2 Et H H H H Me 482 9 CO 2 Et H H H H Me 424 10 CO 2 H H H H H Me 376 11 CO 2 Et Ph H H H H Me 344 12 CO 2 Et H H H H Me 374 13 CO 2 Et H H H H Me 434 14 CO 2 Et H H H H Me 454 15 CO 2 Bn H H H H Me 450 16 H H H H Me 507 17 CO 2 Me H H H H Me 390 18 CO 2 Me H H H H Me 374 19 CO 2 Et H H H H Me 404 20 CO 2 Et H H H H Me 404 21 CO 2 Et H H H H Me 454 22 CO 2 Et H H H H NH 2 411 (M + 23) 23 CO 2 Et H H H H Me 388 25 CO 2 Et H H H H NH 2 405 26 CO 2 Et H H H H NH 2 390 27 CO 2 Et Ph H H H H NH 2 345 28 CO 2 Et H H H H Me 402 29 CO 2 Et H H H H Me 483 30 CO 2 Me Ph H H H H Me 330 31 CO 2 Et H H H H Me 402 32 CO 2 Et H NO 2 H H Me 433 33 H H H H Me 413 34 CO 2 Et H H H H Me 433 35 CO 2 Et H H NO 2 H Me 433 36 CO 2 Me H H H H Me 398 37 CO 2 Et H H NH 2 H Me 403 38 CONH 2 H H H H Me 359 39 CO 2 Et H H H H Me 372 40 CO 2 Et H NH 2 H H Me 403 41 CO 2 Et H H H H Me 334 42 CO 2 Et 2-Thienyl H H H H Me 350 43 CO 2 Me H H H H Me 358 44 CO 2 Me H H H H Me 388 45 CO 2 Me H H H H Me 419 46 CO 2 Me H H H H Me 388 47 CO 2 Me 4-Pyridyl H H H H Me 331 48 CO 2 Me H H H H Me 374 49 CO 2 Me H H H H Me 454 50 CO 2 Me H H H H Me 439 51 CO 2 Me H H H H Me 358 52 CO 2 Et H H H H Me 372 53 CO 2 Me H H H H Me 410 54 CO 2 Me H H H H Me 375 55 CO 2 Et H NHAc H H Me 445 56 CO 2 Et H H NHAc H Me 445 57 CO 2 Et H H H H Me 358 58 CO 2 Et H H H H Me 358 59 CO 2 Et H H H H Me 358 60 CO 2 Et H NO 2 H H Me 457 61 CO 2 Et H H NO 2 H Me 457 62 CO 2 Me H H H H Me 344 63 CO 2 Et H NH 2 H H Me 427 64 CO 2 Et H H NH 2 H Me 427 65 CO 2 Me H H H H Me 466 66 CO 2 Me H H H H Me 344 67 CO 2 Me H H H H Me 344 68 CO 2 Me H NO 2 H H Me 443 69 CO 2 Me H H NO 2 H Me 443 70 CO 2 Et H H H H i-Pr 400 71 CO 2 Me H NH 2 H H Me 413 72 CO 2 Me H H H H Me 399 73 CO 2 Me H H H H Et 372 74 CO 2 Me H H H H Me 398 75 CO 2 Me H H H H Me 394 76 CO 2 Me H H H H Me 372 77 CO 2 Me H NO 2 H H Me 403 78 CO 2 Me H H NO 2 H Me 403 79 CO 2 Me H H H H Me 394 80 CO 2 Me H NHAc H H Me 455 81 CO 2 Me H H H H Me 488 82 CO 2 Me H NH 2 H H Me 373 83 CO 2 Me H H NH 2 H Me 373 84 CO 2 Me H H H H Me 362 85 CO 2 Me H H H H Me 431 (M + 23) 86 CO 2 Me H H H H Me 380 (M + 23) 87 CO 2 Me H NO 2 H H Me 439 88 CO 2 Me H H NO 2 H Me 439 89 CO 2 Me H H H H Me 430 90 CO 2 Me H NH 2 H H Me 409 91 CO 2 Me H H NH 2 H Me 409 92 H H H H Me 397 93 CN H H H H Me 325 94 CO 2 Me H H H H NH 2 359 95 CO 2 Me H H H H NH 2 395 96 CO 2 H H H H H Me 344 97 H H H H Me 433 98 CN H H H H Me 361 99 H H H H C 2 H 2 O 2 358 100 H H H H C 2 H 2 O 2 357 101 Ph H H H H C 2 H 2 O 2 314 102 p-C 6 H 4 NO 2 H H H H C 2 H 2 O 2 361 103 H H H H C 2 H 2 O 2 364 104 H H H H C 2 H 2 O 2 342 105 CO 2 H H H H H Me 380 106 CONH 2 H H H H Me 343 107 CONHMe H H H H Me 357 108 CONMe 2 H H H H Me 371 109 H H H H C 2 H 2 O 2 378 110 H H H H C 2 H 2 O 2 328 111 H H H H C 2 H 2 O 2 356 112 H H H H C 2 H 2 O 2 328 113 CO 2 Me H H H H Me 375 114 H H H H C 2 H 2 O 2 328 115 CO 2 Me H H H H Me 373 116 CONH 2 H H H H Me 379 117 H H H H C 2 H 2 O 2 365 118 CO 2 Me H H H H Me 375 119 CONHMe H H H H Me 393 120 CONMe 2 H H H H Me 407 121 CO 2 Me H H H H Me 381 122 CO 2 Me H Cl Cl H Me 463 123 CO 2 Me H Cl Cl H Me 427 124 CO 2 Me H H H H Me 381 125 CO 2 Et H H H H Me 408 126 CO 2 Me H Cl Cl H Me 555 127 CO 2 Me Cl H H Cl Me 427 128 CO 2 Me 2-NO 2 -4,5- H H H H Me 421 OCH 2 O— C 6 H 2 129 CO 2 Me Cl H H Cl Me 558 130 CO 2 Me H H H H Me 345 131 CO 2 Et H Cl Cl H Me 477 132 CO 2 Me H H H H Me 503 133 Ac H H H H Me 472 134 Ac H H H H Me 342 135 CO 2 Me H H H H Me 331 136 H H H H Me 527 137 H H H H Me 397 138 CO 2 Me H H H H Me 362 139 CO 2 H H H H H Me 474 140 CO 2 H H H H H Me 344 141 CO 2 Me H H H H Me 346 142 CO 2 Me H H H H Me 380 143 CO 2 Me H H H H Me 486 144 CO 2 Me H H H H Me 436 145 CO 2 Me H H H H Me 518 146 H H H H Me 557 147 H Cl Cl H Me 466 148 CO 2 Et —NHPh H H H H Me 359 149 CO 2 Me H H H H Me 360 150 CO 2 Me H H H H Me 504 151 H H H H Me 420 152 C 3 H 5 O 3 H H H H Me 534 153 H H H H Me 385 154 H H H H Me 373 155 H H NO 2 H Me 574 156 CO 2 Me H Br H H Me 473 157 CO 2 Me H H Br H Me 473 158 H Cl Cl H Me 489 159 H H NO 2 H Me 590 160 H H H H Me 411 161 CO 2 Me H Br H H Me 436 162 CO 2 Me H H Br H Me 438 163 CO 2 Me H Br Br H Me 516 164 H Cl Cl H Me 597 165 H Cl Cl H Me 480 166 CO 2 Me H Br Br H Me 552 167 CO 2 Et H Br Br H Me 530 168 CO 2 Me F H H F Me 540 169 CO 2 Me H H NO 2 H Me 551 170 CO 2 Me H Cl Cl H Me 573 171 H H NO 2 H Me 444 172 H NO 2 H H Me 444 173 CO 2 Me F H H F Me 394 174 F H H F Me 433 175 CO 2 Me H Br Br H Me 548 176 CO 2 Me H H H H Me 355 177 CO 2 Me H NO 2 H H Me 421 178 CO 2 Me H H NO 2 H Me 453 (M + 23) 179 CO 2 Me H Cl Cl H Me 443 180 CN H H H H Me 341 181 CO 2 Me H H H H Me 598 182 CO 2 Me H Cl Cl H Me 435 183 CO 2 Et H H H H Me 387 184 CO 2 Et H H H H Me 373 185 CO 2 Me H H H H Me 612 186 CO 2 Et H H H H Me 410 187 CO 2 Me H H NO 2 H Me 345 188 CO 2 Me H Cl Cl H Me 668 189 CO 2 Me H H NO 2 H Me 413 190 CO 2 H H Cl Cl H Me 544 191 CN H H H H Me 565 192 CO 2 Me H Br H H Me 606 (M + 23) 193 CO 2 Me H H Br H Me 584 194 CO 2 Et H H H H Me 373 195 CO 2 Et H H H H Me 427 196 CO 2 Et H Cl Cl H Me 587 197 CO 2 Et H H H H Me 437 198 CO 2 Et H H H H Me 389 199 CO 2 Et H H H H Me 612 200 CO 2 Et H Cl Cl H Me 449 201 CO 2 Me H Cl Cl H Me 450 202 CO 2 Me H Cl Cl H Me 465 203 CO 2 Me H H H H Me 396 204 CO 2 Me H H H Me 473 205 CO 2 Me H H H H Me 345 206 CO 2 Me H H H H Me 359 207 CO 2 Me H Cl Cl H Me 444 208 CO 2 Me H H H H Me 355 209 CO 2 H H H H H Me 366 210 CO 2 Me H Cl Cl H Me 444 211 CO 2 Me H Cl Cl H Me 430 212 CO 2 Me H H H H Me 416 213 CO 2 Me H Cl Cl H Me 430 214 CO 2 Me H H H H Me 413 215 CO 2 Me H OMe OMe H Me 418 216 CO 2 Me H OMe OMe H Me 454 217 CO 2 Me H H H H Me 362 218 CO 2 Me H H H Me 445 219 CO 2 Me H H H H Me 359 220 CO 2 Me —NHPh H H H H Me 345 221 CO 2 Me H H H H Me 423 222 CO 2 Me 2-Pyridyl H H H H Me 353 (M + 23) 223 CO 2 Me H OMe OMe H Me 459 224 CO 2 Me H Cl Cl H Me 485 225 CO 2 Me H H H H Me 345 226 CO 2 Me H H NO 2 H Me 420 227 CO 2 Me H H NO 2 H Me 420 228 CO 2 Me H H H H Me 359 229 CO 2 Me H H H H Me 396 230 CO 2 Me H OH OH H Me 426 231 CO 2 Me H H F H Me 376 232 CO 2 Me H H NO 2 H Me 461 233 CO 2 Me H Cl Cl H Me 468 234 CO 2 Me H H H H Me 373 235 CO 2 Me H H H H Me 375 236 CO 2 Me H NO 2 H H Me 443 237 CO 2 Me H H NO 2 H Me 443 238 CO 2 Me H H H H Me 398 239 CO 2 Me H Cl Cl H Me 491 240 CO 2 Me H H H Me 509 241 CO 2 Me H H H Me 473 242 CO 2 Me H H H Me 509 243 CO 2 Me H H H H Me 310 244 CO 2 Me H H H Me 524 245 CO 2 Me H H H Me 488 246 CO 2 Me H H H H Me 308 247 CO 2 Me i-Pr H H H H Me 296 248 CO 2 Me H H H H Me 336 249 CO 2 Me Me H H H H Me 268 250 CO 2 Me H H H Me 474 251 CO 2 Me H H H Me 487 252 CO 2 Me N-Morpholino H H H H Me 339 253 CO 2 Me H H H H Me 337 254 CO 2 Me H H H Me 488 255 CO 2 Me H H H Me 474 256 CO 2 Me H H H Me 456 257 CO 2 Me H H H Me 431 258 CO 2 Me H H H Me 500 259 CO 2 Me H H H Me 499 260 CO 2 Me H H H Me 481 261 CO 2 Me H H H Me 500 262 CO 2 Me H H H Me 499 263 CO 2 Me H H H Me 431 264 CO 2 Me H H H H NH 2 397 (M + 23) 265 CO 2 Me Ph H H H H NH 2 353 (M + 23) 266 CO 2 Me H H H H NH 2 413 (M + 23) 267 CO 2 Me 2-Furyl H H H H NH 2 321 268 CO 2 Me 3-Furyl H H H H NH 2 321 269 CO 2 Me 2-Furyl H H H H Me 320 270 CO 2 Me 2-Furyl H H H NH 2 Me 335 271 CO 2 Me 2-Furyl NHOH H H H Me 351 272 CO 2 Et 2-Furyl H H H H NH 2 335 273 CO 2 Et 2-Furyl H Br H H NH 2 413 274 CO 2 Et 2-Furyl H H Br H NH 2 413 275 CO 2 Et H H H H Me 467 276 CO 2 Me H H H Me 481 277 CO 2 Me H H H Me 456 278 CO 2 Me H H H Me 473 279 CO2Me H H H Me 513 280 CO 2 Me H H H Me 516 281 CO 2 Me H H H Me 501 282 CO 2 Me H H H Me 566 283 CO 2 Me H H H Me 488 284 CO 2 Me H H H Me 541
III. Biological Assays and Activity
Ligand Binding Assay for Adenosine A2a Receptor
Ligand binding assay of adenosine A2a receptor was performed using plasma membrane of HEK293 cells containing human A2a adenosine receptor (PerkinElmer, RB-HA2a) and radioligand [ 3 H]CGS21680 (PerkinElmer, NET1021). Assay was set up in 96-well polypropylene plate in total volume of 200 mL by sequentially adding 20 mL1:20 diluted membrane, 130 mLassay buffer (50 mM Tris-HCl, pH7.4 10 mM MgCl 2 , 1 mM EDTA) containing [3H] CGS21680, 50 mLdiluted compound (4×) or vehicle control in assay buffer. Nonspecific binding was determined by 80 mM NECA. Reaction was carried out at room temperature for 2 hours before filtering through 96-well GF/C filter plate presoaked in 50 mM Tris.HCl, pH7.4 containing 0.3% polyethylenimine. Plates were then washed 5 times with cold 50 mM Tris.HCl, pH7.4., dried and sealed at the bottom. Microscintillation fluid 30 ml was added to each well and the top sealed. Plates were counted on Packard Topcount for [ 3 H]. Data was analyzed in Microsoft Excel and GraphPad Prism programs. (Varani, K.; Gessi, S.; Dalpiaz, A.; Borea, P. A. British Journal of Pharmacology, 1996, 117, 1693)
Adenosine A2a Receptor Functional Assay
CHO-K1 cells overexpressing human adenosine A2a receptors and containing cAMP-inducible beta-galactosidase reporter gene were seeded at 40-50K/well into 96-well tissue culture plates and cultured for two days. On assay day, cells were washed once with 200 mL assay medium (F-12 nutrient mixture/0.1% BSA). For agonist assay, adenosine A2a receptor agonist NECA was subsequently added and cell incubated at 37 C., 5% CO 2 for 5 hrs before stopping reaction. In the case of antagonist assay, cells were incubated with antagonists for 5 minutes at R.T. followed by addition of 50 nM NECA. Cells were then incubated at 37C., 5% CO 2 for 5 hrs before stopping experiments by washing cells with PBS twice. 50 mL 1× lysis buffer (Promega, 5× stock solution, needs to be diluted to 1× before use) was added to each well and plates frozen at −20C. For b-galactosidase enzyme colormetric assay, plates were thawed out at room temperature and 50 mL 2× assay buffer (Promega) added to each well. Color was allowed to develop at 37C. for 1 hr. or until reasonable signal appeared. Reaction was then stopped with 150 mL 1M sodium carbonate. Plates were counted at 405 nm on Vmax Machine (Molecular Devices). Data was analyzed in Microsoft Excel and GraphPad Prism programs. (Chen, W. B.; Shields, T. S.; Cone, R. D. Analytical Biochemistry, 1995, 226, 349; Stiles, G. Journal of Biological Chemistry, 1992, 267, 6451)
Assay of Phosphodiesterase Activity
The assay of phosphodiesterase activity follows the homogeneous SPA (scintillation proximity assay) format under the principle that linear nucleotides preferentially bind yttrium silicate beads in the presence of zinc sulfate.
In this assay, the enzyme converts radioactively tagged cyclic nucleotides (reaction substrate) to linear nucleotides (reaction product) which are selectively captured via ion chelation on a scintillant-containing bead. Radiolabeled product bound to the bead surface results in energy transfer to the bead scintillant and generation of a quantifiable signal. Unbound radiolabel fails to achieve close proximity to the scintillant and therefore does not generate any signal.
Specifically, enzyme was diluted in PDE buffer (50 mM pH 7.4 Tris, 8.3 mM MgCl 2 , 1.7 mM EGTA) with 0.1% ovalbumin such that the final signal:noise (enzyme:no enzyme) ratio is 5-10. Substrate (2,8- 3 H-cAMP or 8- 3 H-cGMP, purchased from Amersham Pharmacia) was diluted in PDE (4, 5, 7A) buffer to 1 nCi per μl (or 1 μCi/ml). For each test well, 48μl of enzyme was mixed with 47μl substrate and 5 μl test compound (or DMSO) in a white Packard plate, followed by shaking to mix and incubation for 15 minutes at room temperature. A 50 μl aliquot of evenly suspended yttrium silicate SPA beads in zinc sulfate was added to each well to terminate the reaction and capture the product. The plate was sealed using Topseal-S (Packard) sheets, and the beads were allowed to settle by gravity for 15-20 minutes prior to counting on a Packard TopCount scintillation counter using a 3 H glass program with color quench correction. Output was in color quench-corrected dpm.
Test compounds were diluted in 100% DMSO to a concentration 20× final assay concentration. DMSO vehicle alone was added to uninhibited control wells. Inhibition (%) was calculated as follows:
Nonspecific binding (NSB)=the mean of CPM of the substrate+buffer+DMSO wells
Total Binding (TB)=the mean of the enzyme+substrate+DMSO wells
% Inhibition listed in Table 1 = ( 1 - ( Sample CPM - NSB ) ) TB - NSB × 100.
The IC 50 values were calculated using the Deltagraph 4-parameter curve-fitting program. The IC 50 and % Inhibition data on PDE 4, 5, and 7A are listed for the indicated compounds in Table 2 below.
TABLE 2
MS
IC 50 (μM)/% inh.@μM
No.
R 1
R 2
R 3a
R 3b
R 3c
R 3d
R 4
(M + 1)
PDE7A
PDE4
PDE5
6
CO 2 H
H
H
H
H
Me
360
45%@ 20
49%@5
51
CO 2 Me
H
H
H
H
Me
358
0.055
0.353
2.7
56
CO 2 Et
H
H
NHAc
H
Me
445
0.074
0.333
2.5
70
CO 2 Et
H
H
H
H
i- Pr
400
2.11
73
CO 2 Me
H
H
H
H
Et
372
1.54
0.998
82
CO 2 Me
H
NH 2
H
H
Me
373
0.021
0.204
1.11, 0.864
90
CO 2 Me
H
NH 2
H
H
Me
409
0.005
0.237, 0.172
2.33
98
CN
H
H
H
H
Me
361
1.13
119
CONHMe
H
H
H
H
Me
393
0.658
41%@ 20
133
Ac
H
H
H
H
Me
472
1.54
134
Ac
H
H
H
H
Me
342
1.14
169
CO 2 Me
H
H
NO 2
H
Me
551
0.0053
0.184
170
CO 2 Me
H
Cl
Cl
H
Me
573
0.0087
0.557
190
CO 2 H
H
Cl
Cl
H
Me
544
5.9
191
CN
H
H
H
H
Me
565
0.593
197
CO 2 Et
H
H
H
H
Me
437
0.728
69%@5
0.362
219
CO 2 Me
H
H
H
H
Me
359
0.964
61%@5
1.1
220
CO 2 Me
—NHPh
H
H
H
H
Me
345
0.084
1.8
0.637
241
CO 2 Me
H
H
H
Me
473
0.0035
0.954
0.183
242
CO 2 Me
H
H
H
Me
509
0.0038
0.782
0.141
243
CO 2 Me
H
H
H
H
Me
310
2.6
245
CO 2 Me
H
H
H
Me
488
0.0053
0.875
0.185
248
CO 2 Me
H
H
H
H
Me
336
0.783
0.171
0.649
250
CO 2 Me
H
H
H
Me
474
0.0074
0.684
2.4
251
CO 2 Me
H
H
H
Me
487
0.0054
0.754
0.26
253
CO 2 Me
H
H
H
H
Me
337
0.905
0.85
0.303
254
CO 2 Me
H
H
H
Me
488
0.0067
0.664
0.765
261
CO 2 Me
H
H
H
Me
500
0.0063
0.477
0.63
262
CO 2 Me
H
H
H
Me
499
0.008
0.702
3.7
TABLE 3
Ki(nM)
A2a
MS
A2a
antagonist
A1
No.
R 1
R 2
R 3a
R 3b
R 3c
R 3d
R 4
(M + 1)
binding
function
binding
14
CO 2 Et
H
H
H
H
Me
454
451
22
CO 2 Et
H
H
H
H
NH 2
411 (M + 23)
70
253
18
CO 2 Me
H
H
H
H
Me
374
159
>1000
584
27
CO 2 Et
Ph
H
H
H
H
NH 2
345
42
36
554
23
CO 2 Et
H
H
H
H
Me
388
251
275
CO 2 Et
H
H
H
H
Me
467
263
41
CO 2 Et
H
H
H
H
Me
334
271
57
CO 2 Et
H
H
H
H
Me
358
400
67
CO 2 Me
H
H
H
H
Me
344
39
128
1853
66
CO 2 Me
H
H
H
H
Me
344
46
151
1591
85
CO 2 Me
H
H
H
H
Me
431 (M + 23)
35
>1000
5570
82
CO 2 Me
H
NH 2
H
H
Me
373
294
95
CO 2 Me
H
H
H
H
NH 2
395
286
135
CO 2 Me
H
H
H
H
Me
331
123
130
CO 2 Me
H
H
H
H
Me
345
222
141
CO 2 Me
H
H
H
H
Me
346
172
183
CO 2 Et
H
H
H
H
Me
387
191
208
CO 2 Me
H
H
H
H
Me
355
171
197
CO 2 Et
H
H
H
H
Me
437
148
217
CO 2 Me
H
H
H
H
Me
362
119
221
CO 2 Me
H
H
H
H
Me
423
76
258
2180
222
CO 2 Me
2-Pyridyl
H
H
H
H
Me
353 (M + 23)
237
198
CO 2 Et
H
H
H
H
Me
389
185
199
CO 2 Et
H
H
H
H
Me
612
301
279
CO2Me
H
H
H
Me
513
179
261
CO 2 Me
H
H
H
Me
500
472
280
CO 2 Me
H
H
H
Me
516
237
276
CO 2 Me
H
H
H
Me
481
304
258
CO 2 Me
H
H
H
Me
500
211
281
CO 2 Me
H
H
H
Me
501
201
262
CO 2 Me
H
H
H
Me
499
332
184
CO 2 Et
H
H
H
H
Me
373
140
195
CO 2 Et
H
H
H
H
Me
427
171
260
CO 2 Me
H
H
H
Me
481
163
263
CO 2 Me
H
H
H
Me
431
480
245
CO 2 Me
H
H
H
Me
488
276
264
CO 2 Me
H
H
H
H
NH 2
397 (M + 23)
342
265
CO 2 Me
Ph
H
H
H
H
NH 2
353
50
(M + 23)
267
CO 2 Me
2-Furyl
H
H
H
H
NH 2
321
<15
268
CO 2 Me
3-Furyl
H
H
H
H
NH 2
321
21
269
CO 2 Me
2-Furyl
H
H
H
H
Me
320
192
270
CO 2 Me
2-Furyl
H
H
H
NH 2
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This invention provides novel arylindenopyridines of the formula:
and pharmaceutical compositions comprising same, useful for treating disorders ameliorated by antagonizing Adensine A2a receptors or reducing PDE activity in appropriate cells. This invention also provides therapeutic and prophylactic methods using the instant pharmaceutical compositions.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 11/700,545, filed Jan. 31, 2007, now U.S. Pat. No. 7,693,623 which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/763,713, filed Jan. 31, 2006, and Ser. No. 60/844,866, filed Sep. 15, 2006. The above applications are incorporated herein by reference in their entirety.
TECHNICAL FIELD
This invention relates to railroad snow removal systems. More particularly, the present invention relates to a monitoring and control system for a network of snow removal devices.
BACKGROUND OF THE INVENTION
During the winter it is not uncommon for snow and ice to accumulate on and around railroad tracks. To maintain optimal track performance it is desirable to keep certain areas of the track free of snow and ice year round. For example, it is particularly desirable to keep the areas where tracks cross each other (frogs) and where tracks merge or split (switches) free of snow and ice. Though the system of the present disclosure will be described herein primarily with reference to railroad track switches, the description is not meant to be limiting. It should be appreciated that the system is applicable to other applications as well.
Railroad track switches are used to divert a train from one train track to another train track. The railroad switches typically include a pair of rails that move from a first position to a second position. The switches typically include moving parts that are exposed to the environment. Snow and ice build-up on the switch can cause the switch to malfunction.
A number of different types of railroad track switch snow removers are known. See, for example, U.S. Pat. No. 5,824,997 to Reichle et al.; U.S. Pat. No. 4,391,425 to Keep, Jr.; and U.S. Pat. No. 4,081,161 to Upright. The railroad track switch snow remover often includes a blower that blows heated air or ambient air across the switch. Though some heaters and blowers of the snow removing devices are electric powered, most are gas powered, as they are typically located in remote locations. Sometimes the snow removers include temperature and moisture sensors so that an operator at a remote location can determine when to turn the devices on or off. Some devices are programmed to automatically turn themselves on or off depending on the reading from the sensors.
A problem with the existing systems is that malfunctioning device can be difficult to identify. In some cases, the devices are turned on when it is not snowing or turned off when it is snowing. In the first case, fuel is wasted, and in the second, the switch may malfunction due to undesirable snow accumulation in the tracks. Moreover, existing switch snow removal control systems are not configured to collect, store, and/or report data regarding performance and other conditions of the device. A system that can be used to effectively monitor and control snow removal devices located in remote locations is desirable.
SUMMARY OF THE INVENTION
The present invention relates to a system for controlling and monitoring snow removal devices. According to one embodiment, the snow removal devices include sensors for measuring data, and a processor remotely transmits the measured data to a base station. In some embodiments the measured data is environmental data that can be accessed by an operator remotely on a handheld device or at a computer terminal operably connected to the snow removal devices. In such an embodiment, the operator can monitor the device and choose to override the automated operation of the snow removal devices.
According to another embodiment, the geographic location of each snow removal device is stored in a memory location on the device or at the base station, and the base station is configured to query the weather conditions at the stored geographic location.
In one embodiment, the measured data is compared with the queried data. If the measured data is within a certain predetermined acceptable range compared to the queried weather data, the snow removal device is characterized as being operational. However, if the sensor reading is outside of a predetermined range the operator is alerted. In an alternative embodiment the query data is processed to determine whether the snow removal device that corresponds with the particular geographic location should be on or off. The base station then determines whether the snow removal device is in fact on or off. If there is a discrepancy, the base station automatically notifies an operator.
In another embodiment the queried and measured data relate to the operational conditions of the device rather than environmental conditions. For example, the data may relate to the amount of fuel consumed by the device or amount of fuel remaining in the device. The measured data can be compared with data stored on a database that can be accessed by the base station. If a discrepancy is detected, the operator is alerted.
According to another embodiment the user can monitor and control the device via a computer or a handheld wireless computing device. The data is represented graphically to the operator via icons on a map, and the devices can be controlled by the user remotely.
A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to an individual feature or to a combination of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of a method of monitoring and controlling railroad switch snow removal devices in accordance with an embodiment of the invention;
FIG. 2 is a flow chart of an alternative method of monitoring and controlling railroad switch snow removal devices in accordance with an embodiment of the invention;
FIG. 3 depicts the network including a plurality of railroad switch snow removal devices according to an embodiment of the invention;
FIG. 4 is a schematic block diagram of a snow removal control unit according to an embodiment of the invention;
FIG. 5 depicts a user interface according to an embodiment of the invention;
FIG. 6 is a schematic illustration of a fuel tank monitoring system according to one embodiment of the invention;
FIG. 7 is a schematic illustration of several possible scenarios that are used to describe the operations of the invention;
FIG. 8 is a screen shot that displays a summary of the operating conditions of related snow melters according to an embodiment of the invention;
FIG. 9 is a screen shot that displays the detailed operating conditions of a selected snow melter according to an embodiment of the invention;
FIG. 10 is a screen shot that displays the control modes and on/off parameters of a selected snow melter according to an embodiment of the invention;
FIG. 11 is a screen shot that displays user rights to snow melters according to an embodiment of the invention;
FIG. 12 is a screen shot that displays fault notifications of snow melters according to an embodiment of the invention;
FIG. 13 is a screen shot that displays the location and identification of snow melters according to an embodiment of the invention;
FIG. 14 is a schematic diagram of an embodiment of the network according to the present disclosure; and
FIG. 15 is a schematic diagram of the embodiment of the network shown if FIG. 14 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring primarily to FIGS. 1 and 3 , a method of monitoring railroad switch snow removal devices 200 is shown. The first step includes identifying 10 a device and checking if the device 200 (shown schematically in FIG. 4 ) is on or off. In some embodiments the geographic location is stored at the base station 202 corresponding to a particular device identification number. In another embodiment the geographic location is stored at a memory location 301 at snow removal device 200 . The geographic location can be any number of references. In some embodiments, the geographic location is identified as specific geographic coordinates (e.g., longitude and latitude), while in other embodiments the geographic location is identified as a particular zip code. For example, referring to FIG. 13 , the snow melter is shown associated with a serial number, name, zip code, latitude, longitude, region, division, subdivision, and mile post. In some embodiments the above information is recorded and tracked by a provider upon installation of the snow removal devices.
Next, the base station 202 collects 20 weather data from a secondary source 204 that corresponds to the particular identified geographic location. Some exemplary secondary sources for weather data include: www.weather.com, www.cnn.com/weather/, and www.wunderground.com. Once the weather data is queried, the base station 202 determines 30 whether the device 200 should be on or off and checks 40 for any discrepancy. For example, if the secondary source indicates heavy snow at the particular geographic location, then the device should be on. In contrast, if the secondary source indicates that it is warm and sunny at the particular geographic location, the device should probably be turned off. If a discrepancy is detected, an operator 206 is alerted 50 so that the operator can investigate the discrepancy.
Referring to FIGS. 2 and 4 , an alternative method of monitoring and controlling railroad switch snow removal devices 200 is shown. The first step includes measuring 100 operating and environmental conditions. This step, for example, may include the step of measuring the ambient temperature, the ambient moisture content, and the available fuel. The next step is processing the data 112 by comparing 120 the measured data to a predetermined set of criteria. This step can include comparing the data with a predetermined set of criteria saved in a local memory location 301 to determine if snow is falling and if the device has enough fuel to run properly. In some embodiments this step is accomplished locally by the processor 300 that is located at the snow removal device 200 . In some embodiments, depending on the rate of snowfall, the ambient temperature, and the available fuel, the snow removal device 200 may automatically turn on or off as appropriate to ensure that snow and ice do not accumulate on the rails 402 of the switch 400 . In some embodiments the temperature of the heating or lack thereof is determined based on the measured criteria. For example, if the snow is determined to be dry and light, the heater 302 of the snow removal device 200 may be left off to conserve fuel and only the blower 304 will be turned on.
Referring primarily to FIGS. 2 , 3 and 4 , in some embodiments if the measured values are outside of a predetermined set of values an alert is transmitted 116 to the base station 202 . In some embodiments the base station 202 is configured to translate the received signal and determine, for example, whether a particular sensor 306 , 308 , 310 , 312 has malfunctioned or if the device is out of fuel. When an alert is sent, an operator 206 can view the alert remotely when connected to the base station 202 . In some embodiments the base station 202 is configured to page the operator 206 whenever a certain type of alert is received. For example, the base station 202 may be programmed to page the operator 206 when a snow removal device 200 has run out of fuel and snow is falling at that particular location. Such an alert enables an operator 206 to anticipate the failure of the particular switch 400 and make alternative arrangements as necessary.
Still referring primarily to FIGS. 2 , 3 and 4 , in the depicted embodiment the base station 202 measures 100 data from the snow removal devices 200 according to a maintenance check schedule. In some embodiments the collection of data is accomplished by configuring the snow removal devices 200 to periodically or continuously transmit measured data back to the base station 202 . In other embodiments, the base station 202 is configured to query data from the snow removal devices 200 at certain times or on command. The base station 202 also collects 118 a comparable set of data from a secondary source 204 . It should be appreciated that the step of collecting data from a secondary source can occur before, after, or simultaneously with the step of collecting data from the devices 200 . The secondary source 204 in some embodiments includes real time weather information. In other embodiments the secondary source includes maintenance records, such as the last time the snow removal devices 200 were refueled. Subsequently, the data collected from the snow removal devices 200 is compared with the data collected from the secondary sources 204 . If the datum from the snow removal devices 200 and the secondary sources 204 are outside of an acceptable range, an alert is triggered at the base station.
An alert may indicate, for example, that the snow removal device 200 is apparently low on fuel, even though the secondary source 204 maintenance records indicate that the snow removal device 200 was recently refueled. Once alerted to the discrepancy, the operator can investigate the issue further to determine if the snow removal device 200 is leaking, if the secondary source 204 maintenance records are inaccurate, or if the fuel sensor is inaccurate. If the operator 206 decides that the measured value is inaccurate, the operator 206 can reset (e.g., recalibrate) 122 the sensor or otherwise dismiss 126 the alert. In some embodiments the recalibration can be accomplished remotely, and in other embodiments the recalibration is accomplished via the user interface 314 located locally on the snow removal device 200 . In such embodiments the device 200 includes a receiver in addition to the transmitter 612 .
Alternatively, an alert may indicate, for example, that the measured temperature is substantially different than the temperature collected from the secondary weather data source that corresponds to the particular geographic location, which is measured and stored in a memory location. Once alerted of the discrepancy, the operator 206 may choose to override 124 the automatic on off control of the snow removal device 200 if appropriate, or otherwise dismiss 126 the alert. In such embodiments the device 200 includes a receiver in addition to the transmitter 612 . An operator 206 can check other nearby sensors or other secondary sources to determine whether the measured data or the queried data is more likely accurate.
Finally, the base station 202 can be configured to store 128 all the dates and times that the measured data from each snow removal device 200 was checked against data from a secondary source 204 . In some embodiments the next date and time that the measured data from that particular snow removal device 200 is check against data from a secondary source 204 is dependent on when the last check occurred and the outcome of the last check. In some embodiments, a number of different types of measured data is stored at the base station for maintenance purposes.
Referring primarily to FIG. 5 , according to one embodiment of the invention the data transmitted and processed at the base station can be accessed via an internet webpage. The data can in some embodiments be graphically represented via icons 401 , 403 , 404 , 406 , and 408 along tracks 410 on a map displayed on a computer screen 414 . The user can check the operational parameters and the measured data by clicking on the icon that corresponds with the snow removal device 200 of interest. In some embodiments an alert is indicated on the map by a flashing icon or an icon that turns a particular color, such as orange or red. In other embodiments, the color of the icon 401 , 403 , 404 , 406 , and 408 corresponds with whether the particular corresponding snow removal device 200 is on or off or is full or low on fuel.
According to some embodiments the data can be accessed by the operator 206 wirelessly on a handheld device 500 . In such an embodiment the operator can be in transit to service a particular snow removal device 200 and access real time data regarding the snow removal devices 200 in the field.
Referring to FIG. 6 , an embodiment is shown where fuel tank related data is measured to determine if the tank 600 is expected to be operational. To be operational the tank 600 must be able to supply fuel to the burner 604 . In the depicted embodiment the supplied fuel 618 is in gas form (e.g., propane or natural gas). To enable larger amounts of fuel 602 to be stored within the tank 600 , the fuel 602 in the depicted embodiment is pressurized so that most of the fuel 602 in the tank 600 is in liquid form. Fuel must change phase from liquid to gas to be effectively used. Accordingly, the mere fact that the tank 600 is not empty does not necessarily mean that the tank 600 is expected to be operational. Since whether a particular liquid will change into a gas is dependent on the temperature of the liquid and the pressure in the tank 600 , the temperature of the fuel 602 within the tank 600 and the pressure within the tank 600 factor into whether the tank 600 is operational (the colder a liquid is, the less likely the liquid will vaporize at a given pressure). In view of the above, as compared to only knowing the amount of fuel 602 in the tank 600 , also knowing the temperature of the fuel 602 , and the pressure within the tank 600 enables one to more accurately predict whether the tank 600 is operational.
According to one embodiment, to accurately estimate whether the tank 600 will be operational under certain conditions, preferably at least the following types of data are measured: the temperature in the tank 600 or the fuel 602 therein, the pressure within the tank 600 , and the level of liquid fuel within the tank 600 . Accordingly, to such an embodiment the system includes a temperature sensor 606 , a pressure sensor 608 , and a fuel level sensor 610 . It should, however, be appreciated that in alternative embodiments sensors measuring different data may be included. It should also be appreciated that alternative embodiments may include more or fewer sensors in part depending on the specific methodology used to analyze the data, which will be discussed in greater detail below. It should be appreciated that in alternative embodiments an electric heat non-combustion source may be employed (e.g., electric calrod heater). Such systems could include a system for measuring whether the necessary electric energy exists, similar to the fuel tank monitoring system described above.
In the depicted embodiment the sensors are connected to a transmitter 612 that is configured to transmit the measured data to a remote base station 614 or a network server 616 or both. In one embodiment the base station 614 uses equations to calculate whether or not the tank 600 is expected to be operational based on the measured data and known or inputted data. In other embodiments the base station 614 relies on empirical data to make its determination regarding the operability of the tank 600 . In yet other embodiments, a combination of empirical charts and equations are used in the analysis. In embodiments where empirical data is used in the analysis, the empirical data may be stored locally on a remote database and accessible via a network. In the depicted embodiment the empirical data is stored on a remote server 616 and accessible via the internet 620 . Base station 614 can be connected to the transmitter 612 via the cellular telephone network directly, or via a short range wireless communication system such as any of a variety of 802.11 wireless networks (e.g., Wi-MAX or Wi-Fi) or any radio or other wireless or wire communication systems.
In some embodiments the base station 614 tracks and stores the measured data to analyze the fuel usage history. For example, in some embodiments the level of fuel in the tank 600 is tracked over a set period of time. Such tracking can be used for many purposes including, for example, determining whether the measured data is likely accurate or inaccurate, or whether the sensors are operable and/or whether the tank 600 is leaking. For example, if the tracked history indicates that the tank 600 was initially full and has been in use for a very short period of time or no time at all but is now empty, the tank 600 may be leaking or the measured data may be inaccurate. In some embodiments the base station 614 is configured to alert the operator when a potential problem is detected.
The system disclosed in FIG. 6 , may also be used by an operator in determining the type of fuel that should be used for a particular application. In some embodiments the conditions, such as the expected ambient temperatures, may make a certain type of fuel preferable. The effectiveness and efficiency of particular fuels can be analyzed at the base station 614 based on the data collected by the sensors 606 , 608 , and 610 . It should be appreciated that many other analyses can be conducted based on data measured by the sensors and/or data queried from a local or remote server 616 .
Referring to FIG. 7 , the process of determining when it is appropriate to alert the operator of a failure or otherwise initiate the process of override, the operations of a failed device is illustrated. It is desirable to avoid false detection of device failures, which are the results of normal error. For example, for a period of time the device might be ON while it is snowing. During this period the operation of the system may be characterized by the upper left quadrant (i.e., the device is ON and the device should be ON). The snow might stop, but for a relatively short period of time the device might still be ON. During this period the operation of the system can be characterized as having moved to the lower left quadrant (i.e., the device is ON and the device should be OFF). During this time period, fuel is being wasted. This might occur because the sensors on the device, or the empirical data, or both, are slightly off. To avoid alerting the operator relating to small discrepancies which in time correct themselves, the system can be set up such that the system must operate in the lower left state for more than an hour before an alert is sent to the operator or a failure is otherwise deemed. On the other hand, the system be might be operating in the upper left quadrant and move to the upper right quadrant. This would occur if snow continue to fall, but the device turns itself off (i.e., the device is OFF and the device should be ON). Since it is important to prevent railroad switch failure, the system might be set to alert an operator or otherwise consider the discrepancy a failure after a relatively shorter period of time, for example, 10 minutes instead of an hour.
Still referring to FIG. 7 , as discussed above the time period for acceptable discrepancies is dependent on the type of discrepancy (i.e., if the device is ON when it should be off versus the device is off when it should be on). Another factor can relate to the context (i.e., what quadrant was the device previously operating in). For example, there may exist reasons to set different acceptable time periods of discrepancies based on whether the device moves into the upper right quadrant from the upper left quadrant or from the lower right quadrant. If the device moves to the lower right quadrant from the upper right quadrant (i.e., it starts from the state where it is OFF and it should be OFF, and moves to the state where it is OFF but should be on), the period of time of acceptable discrepancy might be longer than if the device moves to the same quadrant from the upper left quadrant. The latter occurrence might more likely indicate a failure, whereas the former might more likely indicate normal sensor variations.
Referring to FIGS. 8-13 , a specific embodiment of an internet based system is described in greater detail below. FIG. 8 is a screen shot showing a summary of the operating condition of snow melters under the control of a particular user. In the depicted embodiment, the summary of the snow melters can be organized by the user according to region, division, subdivision, mile post, or site group. In the depicted screen shot the designated region is North and the designated division is Twin Cities. Three snow melters fall within this category (i.e., East Wayzata, West Delano, and West Wayzata). The subdivision, mile post, and temperature for each of the three melters are displayed. In addition, the status and whether the melters are running are also displayed. From this screen the user can select any one of the three snow melters for further analysis.
FIG. 9 is a screen shot that corresponds with the East Wayzata snow melter shown in FIG. 8 . In addition to the summary information regarding the snow melter, detailed information relating to the control and operation parameters are displayed. In the depicted screen shot, East Wayzata is not running due to the air temperature, as shown under the machine status column. Other status options include Idle, Running-OK, Not Running-Faulted, Not Running-Timed Out, Not Running-Should Be-Weather, Running-Should Not Be-Weather, and Communication Failure. In the depicted embodiment, action is called (not running due to air temperature) for by the Weather Watcher system, which is driven by the secondary source data. In the depicted embodiment the secondary source data can be used as a check on the local sensors and controls on the snow melter, or it can be used to drive the system. If the local controls and sensors are used to drive the action of the system, the secondary weather data is used as a check and issues alerts when a discrepancy is detected.
Still referring to FIG. 9 , from this view the user can view an array of current status data that includes: fuel tank level, temperature set points, run time data, air temperature, rail temperature, motor voltage, duct pressure, gas pressure, total gas used, motor current, etc. Also, a link is provided to view a snapshot of the site to enable the operator to view the site. The fuel tank level is used to determine if the tank needs to be refilled, and also to calculate whether the tank is operational based on the temperature and other factors. The motor voltage and current are used to determine if the snow melter motor is operational, and also if the motor is running optimally or likely to fail. The duct pressure and gas pressure are used to troubleshoot, and also used to determine if the tank is expected to be operational. In addition, from this view the user clicks on tabs to further investigate the last fault reading, the operational history, and other control settings.
FIG. 10 is a screen shot that corresponds with the Controls tab of FIG. 9 . From this view the user can remotely operate the snow melter. The user can turn on or off the snow melter, adjust the temperature set points, and adjust the run times. In the depicted view the snow melter is configured to turn on continually when the air temperature is less than one degree Fahrenheit. The air temperature set point can also be used to prevent the snow melter from turning on. For example, the system can be configured such that if a sensed temperature is above a certain level, the device does not turn on.
Referring to FIG. 11 , a screen shot of the user assignment page is shown. The user assignment function allows for different levels of access rights to be assigned to different operators. Some operators can be authorized only to view the system, and others can be authorized to edit and modify the system. Moreover, those who are authorized to edit and modify the system may be authorized to edit and modify specific aspects of the system (e.g., gas, run hours, fault counts, and overtemp latch). In the depicted embodiment, all of the operators have full authorization to the system.
Referring to FIG. 12 , a screen shot of the notification setup is shown. The notification function allows for selective notification. Particular types of notification can be sent to particular users via particular means. For example, in the depicted embodiment, Peter Molenda is set to receive notification of fuse 2 faults by email only, whereas Eric Schneider is set to receive fuse 1 faults via cell phone, temperature faults via pager, and fuse 2 faults via email and work phone. In the depicted embodiment, the system administrator is set to receive notification of all of the faults. This system enables the messages to be sent to the person who is responsible for or best suited to dealing with the particular issue. FIG. 13 , as discussed above, is used to log in the identifying information of each of the snow melters.
Referring to FIGS. 14 and 15 , a general overview of a particular embodiment of a network according to the present disclosure is included below. The components of the network architecture include: SMC—Snow Melter Controller; RCC—Remote Communications Controller; WEB—Web services and portal hosting; SQL—SQL Server database; RR—Railroad client accessing web portals.
The general messaging flow scenarios are summarized below in outline form:
1. SMC Initiated
SMC RCC SMC detects a change of operating state (i.e. from off to running) and initiates a conversation with the RCC. SMC sends a message to the RCC containing the current snow melter operating and configuration parameters. RCC accepts and acknowledges the message from the SMC. SMC closes the conversation with the RCC after 1 minute of idle time. RCC captures the parameter values from the message. RCC WEB RCC initiates a conversation with the WEB. RCC sends the current snow melter parameters to the WEB. WEB acknowledges the message from the RCC. RCC closes the conversation with the WEB immediately. WEB captures the parameter values from the message. WEB updates the SQL database with the snow melter parameter values. WEB USER WEB analyzes the snow melter change of state to determine notification requirements. WEB issues notification messages to railroad clients for new snow melter conditions.
2. RCC Initiated
RCC SMC RCC initiates a conversation with the SMC. RCC sends a message to the SMC containing the command number. SMC accepts and acknowledges the message from the RCC. Included in the acknowledgement are all SMC parameter values. RCC closes the conversation with the SMC after 1 minute of idle time. RCC captures the parameter values from the message. RCC WEB RCC initiates a conversation with the WEB. RCC sends the current snow melter parameters to the WEB. WEB acknowledges the message from the RCC. RCC closes the conversation with the WEB immediately. WEB captures the parameter values from the message. WEB updates the SQL database with the snow melter parameter values. WEB USER WEB analyzes the snow melter change of state to determine notification requirements. WEB issues notification messages to railroad clients for new snow melter conditions.
3. WEB Initiated
WEB RCC WEB user presses the “Refresh Values” button on a web page. WEB initiates a conversation with the RCC. WEB sends a message to the RCC containing the command number. RCC accepts and acknowledges the message from the WEB. RCC SMC RCC initiates a conversation with the SMC. RCC sends a message to the SMC containing the command number. SMC accepts and acknowledges the message from the RCC. Included in the acknowledgement are all SMC parameter values. RCC closes the conversation with the SMC after 1 minute of idle time. RCC captures the parameter values from the message. RCC WEB RCC initiates a conversation with the WEB. RCC sends the current snow melter parameters to the WEB. WEB acknowledges the message from the RCC. RCC closes the conversation with the WEB immediately. WEB captures the parameter values from the message. WEB updates the SQL database with the snow melter parameter values. WEB USER WEB analyzes the snow melter change of state to determine notification requirements. WEB issues notification messages to railroad clients for new snow melter conditions.
From the foregoing detailed description, it will be evident that modifications and variations can be made in the devices and methods of the disclosure without departing from the spirit and scope of the invention.
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A snow removal system wherein snow removers located in remote locations can be monitored and controlled at a computing device. Data collected by sensors on the snow removal unit or data collected from a secondary source can be used to control the operation of the snow removers. In one embodiment, data regarding whether it is snowing at a particular location can be collected by moister sensors on the snow removal device and verified by on-line contemporaneous weather reports corresponding to the same location.
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BACKGROUND
The present invention relates generally to inlet swivels for hose reels. More particularly, the present invention relates to bearing arrangements for swivels capable of transmitting high-pressure fluids while also minimizing pressure drop.
Hose reels are commonly used in fluid handling industries, such as for the dispensing of pressurized air, lubricants, adhesives and the like. In these and other applications, bulk quantities of the pressurized fluid are distributed in much smaller volumes using a dispenser that is separated from a storage vessel via a hose. Lengthy hoses are used to facilitate wide ranging of the dispenser to many different distribution points. Hose reels are used to conveniently wind and un-wind the hose, thereby reducing the potential for damaging the hose or people tripping over the hose.
Typical hose reels utilize a swivel that is positioned at the axis of rotation of the reel. An inlet end of the swivel receives fluid from the bulk container, and delivers the fluid to a stationary frame of the hose reel assembly. A rotating end of the swivel receives fluid from the inlet end, and allows the hose to rotate with a drum of the hose reel assembly. The swivel is subject to axial loading from pressurized fluid flowing through the swivel and radial loading from the weight of the drum and hose. In order to withstand or eliminate the axial loading, typical high-pressure swivel couplings utilize a “balanced seal” design. In a typical balanced seal design, a non-rotating post having transfer holes, or perforations, can be joined to a sleeve that rotates about the post, forming a fluid path from the inside of the post, through the perforations and into the sleeve. Such a swivel is described in U.S. Pat. No. 5,052,432. The transfer holes, however, introduce a constriction into the fluid passage that generates an undesirable pressure drop and that also result in stress concentrations that limit the pressure rating of the swivel.
SUMMARY
A hose reel bearing arrangement supports a rotatable swivel shaft on a stationary hose reel frame. The bearing arrangement comprises a stationary bearing race, a rotating bearing race and a bearing. The stationary bearing race is anchored to the stationary hose reel frame, and has a stationary arcuate land for bearing an axial load, a stationary cylindrical land for bearing a radial load, and a stationary frustoconical intervening portion. The rotating bearing race is anchored to the rotatable swivel shaft, and has a rotating arcuate land for bearing the axial load, a rotating cylindrical land for bearing the radial load, and a rotating frustoconical intervening portion. The bearing is bracketed axially by the stationary arcuate land and the rotating arcuate land, and radially by the stationary cylindrical land and the rotating cylindrical land.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a hose reel having a high pressure swivel connecting a frame to a spool.
FIG. 2 is a cross-sectional view of the hose reel of FIG. 1 showing a high pressure swivel having an inlet housing and an outlet housing connected by a swivel shaft.
FIG. 3 is a close-up cross-sectional view of the hose reel swivel of FIG. 2 showing inner and outer bearing races surrounding the swivel shaft.
FIG. 4 is a close-up cross-sectional view of a ball bearing positioned between the inner and outer bearing races of FIG. 3 .
DETAILED DESCRIPTION
FIG. 1 is a perspective view of hose reel 10 having high pressure swivel 12 connecting frame 14 to spool 16 . Frame 14 includes base 18 to which are connected sidewalls 20 A and 20 B. Spool 16 includes drum 22 and disks 24 A and 24 B. Swivel 12 includes a bearing structure that rotatably couples sidewall 20 A with disk 24 A. A similar bearing structure (bearing 26 of FIG. 2 ) rotatably couples sidewall 20 B with disk 24 B. However, swivel 12 provides a fluid coupling between the exterior of frame 14 and the interior of spool 16 so that a hose can be wound around drum 22 .
Frame 14 provides a mounting structure upon which spool 16 can be rotated. Thus, frame 14 remains stationary as hose reel 10 is operated. Spool 16 rotates on swivel 12 and bearing 26 , which extend through the axis of rotation of drum 22 , axis A. As spool 16 rotates, a hose can be wound or un-wound from drum 22 . A hose (or tubing, conduit or the like) may be wound around drum 22 through window 28 , which is lined by rollers 30 A- 30 D to prevent damage to the hose. Swivel 12 allows unrestricted flow of high pressure fluid through swivel 12 to minimize pressure drop. Swivel 12 also includes a bearing that provides sufficient axial strength to counter the load generated by high pressure fluid within swivel 12 , and radial strength to bear the weight of spool 16 and the hose.
FIG. 2 is a cross-sectional view of hose reel 10 of FIG. 1 showing high pressure swivel 12 having inlet housing 32 and outlet housing 34 connected by swivel shaft 36 . Swivel 12 also includes retainer 38 and hub 40 . Spool 16 and outlet housing 34 are configured to rotate about axis A, while inlet housing 32 and frame 14 remain stationary.
Inlet housing 32 and retainer 38 are connected to each other via fasteners (not shown) such that sidewall 20 A is clamped in between. Thus, inlet housing 32 , retainer 38 and all of frame 14 remain stationary during operation of hose reel 10 . Inlet housing 32 may be positioned in different circumferential orientations about axis A with respect to frame 14 to accommodate different supply hose positions.
Swivel shaft 36 is positioned along axis A and is configured to rotate with spool 16 . Swivel shaft 36 extends through an opening in disk 24 A and an opening in hub 40 . Disk 24 A is clamped in between swivel shaft 36 and hub 40 . As such, hub 40 and swivel shaft 36 rotatable about axis A with spool 16 . Swivel shaft 36 is inserted through retainer 38 and into inlet housing 32 . Outlet housing 34 is also connected to swivel shaft 36 within drum 22 . Outlet housing 34 extends through an opening in drum 22 .
Inlet housing 32 , swivel shaft 36 and outlet housing 34 include interior flow passages through which fluid may flow, as is discussed with reference to FIG. 3 . Thus, a supply hose can be connected to inlet housing 32 to provide high pressure fluid to outlet housing 34 , which can be connected to a distribution hose wound around drum 22 between disks 24 A and 24 B. Union fittings may be used to join hoses to inlet housing 32 and outlet housing 34 . Alternatively, a hose may be directly coupled to swivel shaft 36 without the use of outlet housing 34 .
As will be discussed in greater detail with reference to FIGS. 3 and 4 , retainer 38 includes ball bearings situated between a stationary race and a rotating race that permit swivel shaft 36 to rotate within retainer 38 and inlet housing 32 . Swivel shaft 36 includes a non-restricted fluid passage through swivel 12 that allows for coupling to inlet housing 32 and outlet housing 34 without producing a pressure drop. In order to accommodate swivel shaft 36 within swivel 12 and to allow the fluid passage within swivel shaft 36 to pass through retainer 38 , hub 40 , disk 24 A without producing a restriction, retainer 38 includes ball bearing races that counteract the axial and radial forces generated by operation of hose reel 10 and the high pressure fluid flowing between inlet housing 32 and outlet housing 34 .
FIG. 3 is a close-up cross-sectional view of hose reel swivel 12 of FIG. 2 showing inner and outer bearing races 42 A and 42 B surrounding swivel shaft 36 . Swivel shaft 36 includes shaft 44 , outlet socket 46 , flange 48 and fluid passage 50 . Inlet housing 32 includes flange 52 , socket 54 and fluid passage 56 . Outlet housing 34 includes flange 58 and fluid passage 60 . Ball bearings 62 are positioned between the stationary outer race 42 A and the rotating inner race 42 B. Although outer race 42 A is shown integrally formed from retainer 38 , outer race 42 A may be provided by a separate piece positioned within a pocket inside retainer 38 .
As discussed above, inlet housing 32 is joined to retainer 38 to mount hose reel swivel 12 to sidewall 20 A. In particular, flange 52 is connected to outer race 42 A via fasteners (not shown). Thus, outer race 42 A and inlet housing 32 are held stationary via mounting to frame 14 via sidewall 20 A. Hub 40 is joined to swivel shaft 36 to mount outlet housing 34 to disk 24 A. In particular, hub 40 is connected to outlet socket 46 of swivel shaft 36 via fasteners (not shown) at locations 64 . Shaft 44 of swivel shaft 36 extends from outlet socket 46 to pass through bore 68 A in disk 24 A, bore 68 B in hub 40 and bore 68 C in retainer 38 , and into socket 54 . Thus, shaft 44 and inner race 42 B rotate along with disk 24 A of spool 16 . Ball bearings 62 roll between outer race 42 A and inner race 42 B.
Outlet housing 34 is inserted into outlet socket 46 within swivel shaft 36 until flange 58 engages outlet socket 46 . Inner race 42 B is mounted on shaft 44 within channel 70 of outer race 42 A, and is retained by threaded connection and secured by split ring 75 . Inner race 42 B is thus rotatable with swivel shaft 36 , while outer race 42 A is held in place via sidewall 20 A. Connected as such, fluid passages 56 , 50 and 60 are fluidly connected. Fluid passage 50 extends from flange 52 , through retainer 38 and hub 40 and into outlet socket 46 in a linear fashion, thereby eliminating any constrictions between fluid passages 56 and 60 .
Swivel 12 is provided with a variety of different seals, including fluid seals 76 A and 76 B and bearing seals 78 A and 78 B. In the depicted embodiment, fluid seal 76 A comprises an inner plastic sealing member and an outer elastomeric o-ring. However, fluid seal 76 A may comprise other off-the-shelf seals, such as o-rings, lip seals and the like. In the depicted embodiment, fluid seal 76 B and bearing seals 78 A and 78 B comprise o-ring seals, but may be other types of seals. Bearing seals 78 A and 78 B protect ball bearings 62 and races 42 A and 42 B from environmental elements, and may also be used to retain lubricant, such as grease, within races 42 A and 42 B. Fluid seals 76 A and 76 B prevent fluid traveling through fluid passages 50 , 56 and 60 from leaking out of swivel 12 .
Due to the load generated by pressure and large cross-sectional flow areas through fluid passages 50 , 56 and 60 , the axial loading within swivel 12 is greater than conventional hose reel swivels. Inner race 42 A and outer race 42 B are shaped to provide contact surfaces along ball bearings 62 that provide radial and axial support to swivel 12 .
FIG. 4 is a close-up cross-sectional view of ball bearing 62 positioned between rotating, inner race 42 B and stationary, outer race 42 A of FIG. 3 . Outer race 42 A includes axial land 80 A and radial land 82 A, while inner race 42 B includes axial land 80 B and radial land 82 B. Frusto-conical portion 84 A intervenes between axial land 80 A and radial land 82 A, while frusto-conical portion 84 B intervenes between axial land 80 B and radial land 82 B.
Axial lands 80 A and 80 B each form arcuate lands that have generally radial extending surfaces that circumscribe axis A. Axial land 80 A and axial land 80 B have approximately the same radius such that they oppose each other. Axial load L A is borne by axial lands 80 A and 80 B, which is ultimately transmitted to fasteners (not shown) that couple flange 52 of inlet housing 32 with retainer 38 (see FIG. 3 ). Axial lands 80 A and 80 B have radii of curvature C that is slightly larger than the radius of ball bearing 62 , thereby resulting in linear contact between ball bearing 62 and lands 80 A and 80 B.
Radial lands 82 A and 82 B each form cylindrical lands that circumscribe axis A. Radial land 82 A has a larger radius than radial land 82 B, and radial land 82 A radially overlaps radial land 82 B. Radial load L R is borne by radial lands 82 A and 82 B, which is ultimately transmitted to retainer 38 via ball bearings 62 . Ball bearings 62 also permit shaft 44 of swivel shaft 36 to rotate within retainer 38 and socket 54 of inlet housing 32 . Radial lands 82 A and 82 B are generally planar, thereby resulting in point contact between ball bearing 62 and lands 82 A and 82 B. Step 86 on shaft 44 engages with inner race 42 B to prevent translation of swivel shaft 36 under force from axial load L A .
Axial load L A and radial load L R are not transmitted at the edges of races 42 A and 42 B, as would occur in a conventional ball bearing arrangement. Axial lands 80 A and 80 B are positioned in central portions of races 42 A and 42 B, respectively, away from the edges of the races. Radial lands 82 A and 82 B are positioned at the edges of races 42 A and 42 B, respectively, but extend beyond the point of contact with radial load L R to space the load away from the edge of the race. Radial land 82 A forms an extended or extruded portion of race 42 A that is tangent to radial load L R . Likewise, radial land 82 B forms an extended or extruded portion of race 42 B that is tangent to radial load L R .
Lands 80 A and 82 A are separated by frusto-conical portion 84 A, which circumscribe a segment of ball bearing 62 of about fifty degrees or less. Likewise, lands 80 B and 82 B are separated by frusto-conical portion 84 B, which circumscribes a segment of ball bearing 62 of about fifty degrees or less. Portions 84 A and 84 B are curved such that ball bearing 62 will not ever engage portions 84 A and 84 B. Frusto-conical portions 84 A and 84 B, however, provide a gradual blending between axial lands 80 A and 80 B and radial lands 82 A and 82 B, respectively, to reduce stress concentrations in races 42 A and 42 B.
One advantage of swivel 12 is that there are no restrictions in fluid passages 50 , 56 and 60 , which is at least partially enabled by the load bearing capabilities of races 42 A and 42 B. The result of this is lower pressure drop through swivel 12 , which enables higher flow rates. Other advantages include higher pressure ratings and the ability to carry the pressure load, higher hose reel swivel life due to optimized bearing load transmission, and lower turning torques required for spool 16 , which lowers the spring and or motor power required to operate the reel. Swivel 12 provides bearing support for high axial loads induced by high pressures in fluid passage 50 and also radial loads from the weight of spool 16 and hose. The shape of races 42 A and 42 B minimizes Hertzian contact stress concentrations at the bearing race edges. The entire package of swivel 12 allows for a narrower reel footprint which is a desired customer feature.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A hose reel bearing arrangement supports a rotatable swivel shaft on a stationary hose reel frame. The bearing arrangement comprises a stationary bearing race, a rotating bearing race and a bearing. The stationary bearing race is anchored to the stationary hose reel frame, and has a stationary arcuate land for bearing an axial load, a stationary cylindrical land for bearing a radial load, and a stationary frustoconical intervening portion. The rotating bearing race is anchored to the rotatable swivel shaft, and has a rotating arcuate land for bearing the axial load, a rotating cylindrical land for bearing the radial load, and a rotating frustoconical intervening portion. The bearing is bracketed axially by the stationary arcuate land and the rotating arcuate land, and radially by the stationary cylindrical land and the rotating cylindrical land.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel optically active ester compound and a liquid crystal composition containing the same. More particularly, it relates to an optically active ester compound useful as a component of a ferroelectric liquid crystal composition and a ferroelectric liquid crystal composition containing the same.
2. Description of the Prior Art
Although the practical use of a liquid crystal element has started with the application thereof to the display of a watch or an electronic calculator, it is now applied to a widened field including pocket television, various displays and optoelectronic elements. Most of the liquid crystal display elements now used are of TN display type and use nematic liquid crystal materials. Since this type of display is of the photoreception type, it has disadvantages in that the speed of response is low and that the displayed images cannot be seen at some angles of vision, though it has advantages in that the eyes suffer little fatigue and that the power consumption is very low. In order to overcome these disadvantages, a display system using a ferroelectric liquid crystal has recently been proposed. Even in a display element using a ferroelectric liquid crystal, like in the case of the above TN liquid crystal display element, a ferroelectric liquid crystal must be practically used in a state mixed with several liquid crystal or non-liquid crystal compounds, i.e., as a so-called ferroelectric liquid crystal composition, in order to satisfy various characteristics.
On the basis of this idea, Japanese Patent Laid-Open No. 44548/1988 proposed the use of an optically active 2-methyl-1,3-propanediol compound as a component of a ferroelectric liquid crystal composition. However, a ferroelectric liquid crystal composition containing such a compound as a component is not sufficiently improved in the speed of response, though it is somewhat improved. Accordingly, a further improvement in the speed of response of a ferroelectric liquid crystal composition has been expected in order to put the composition to practical use.
SUMMARY OF THE INVENTION
Under these circumstances, the inventors of the present invention have intensively studied to find an optically active compound which can give a ferroelectric liquid crystal composition that is excellent in the speed of response and have found that a novel optically active ester compound represented by the following general formula (I) is very suitable for this object: ##STR3## wherein R stands for a C 1 ˜8 alkyl group or a C 1 ˜18 alkoxy group; R 1 stands for a C 1 ˜18 organic carboxylic acid residue which may be substituted; ##STR4## independent from each other, each stand for a benzene, pyridine, pyrimidine, pyrazine or pyridazine ring which may be substituted; and * stands for an asymmetric carbon atom.
When the optically active ester compound of the present invention represented by the above general formula (I) is used as a component of a liquid crystal composition, an SmC* phase is induced in the composition to bring about an extremely high speed of response and a large spontaneous polarization. Thus, an excellent ferroelectric liquid crystal composition can be provided.
DETAILED DESCRIPTION OF THE INVENTION
The compound represented by the general formula (I) will now be described in more detail.
The C 1 ˜18 alkyl group defined with respect to R includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, lauryl, myristyl, palmityl and stearyl groups, while the C 1 ˜18 alkoxy group includes those derived from the above alkyl groups.
The C 1 ˜18 organic carboxylic acid residue which may be substituted, defined with respect to R', includes not only carboxylic acid residues having alkyl groups described above with respect to R, but also those having alkynyl groups such as 1-butynyl, 2-butynyl, 2-pentynyl or 3-pentynyl group; those each having an alkyl group containing an optically active or racemic methyl group, such as 1-methylbutyl, 2-methylbutyl, 4-methyloctyl, 2,6-dimethylheptyl or 2,6-dimethyl-5-heptenyl; 1-octoxypropionic acid residue; and carboxylic acid residues each having a halogen- or cyano-substituted alkyl group such as 1-chloroethyl, 1-fluoroalkyl, 1-trifluoromethylalkyl, 1-cyano-2-methylbutyl or 1-chloro-2-methylbutyl group.
Although the optically active ester compound of the present invention represented by the above general formula (I) does not always exhibit properties as a ferroelectric liquid crystal by itself, it may be mixed with other liquid crystal or non-liquid crystal compounds to give a practically usable liquid crystal composition. Representative examples of the compound to be mixed include the following compounds, though not limited to them. ##STR5##
These compounds may also be used as a mixture of two or more of them with an arbitrary ratio.
According to the present invention, the optically active ester compound of the present invention is preferably used in an amount of 5 to 30 parts by weight per 100 parts by weight of a matrix liquid crystal (other liquid crystal or non-liquid crystal compound).
The present invention will now be described by referring to the following Examples, though it is not limited by them.
EXAMPLE 1 (SYNTHESIS EXAMPLE 1)
Synthesis of (1"S, 3"R)-4'-octyloxy-4-(1"-methyl-3"-butanoyloxybutyloxy)biphenyl ##STR6##
0.62 g of (R,R)-2,4-pentanediol, 1.49 g of n-octoxybiphenol, 1.57 g of triphenylphosphine and 1.04 g of diethyl azodicarboxylate were dissolved in 25 ml of ethyl ether. The obtained solution was stirred at a room temperature for 3 hours to precipitate triphenylphosphine oxide. The triphenylphosphine oxide was filtered out and the resulting filtrate was freed from the solvent. The solvent-free residue was purified by silica gel column chromatography using a n-hexane/ethyl acetate (7:3) mixture as a developing solvent to obtain 1.71 g of (1"S, 3"R)-4'-octyloxy-4-(1"-methyl-3"-hydroxybutyloxy)biphenyl as a white solid (m.p.: 69.2° to 69.9° C.).
0.38 g of the biphenyl compound prepared above, 0.11 g of butyric acid, 0.62 g of triphenylphosphine and 0.42 g of diethyl azodicarboxylate were dissolved in 10 ml of ethyl ether. The obtained solution was stirred at a room temperature for 2 hours to precipitate triphenylphosphine oxide. This triphenylphosphine oxide was filtered out and the filtrate was freed from the solvent. The solvent-free residue was purified by silica gel column chromatography using a n-hexane/ethyl acetate (95:5) mixture as a developing solvent to obtain 0.35 g of a colorless oil.
The infrared spectroscopic analysis of the oil revealed that the oil had the following characteristic absorptions, and the oil was thus identified as the objective compound:
______________________________________3030 cm.sup.-1 (vw), 2925 cm.sup.-1 (s), 2860 cm.sup.-1 (m),1730 cm.sup.-1 (s), 1605 cm.sup.-1 (s), 1585 cm.sup.-1 (vw),1495 cm.sup.-1 (s), 1470 cm.sup.-1 (m), 1380 cm.sup.-1 (m),2495 cm.sup.-1 (s), 1180 cm.sup.-1 (s), 1105 cm.sup.-1 (m), 820 cm.sup.-1 (s)______________________________________
EXAMPLE 2 (SYNTHESIS EXAMPLE 2)
Synthesis of (1"R, 3"R)-4'-octyloxy-4-(1"-methyl-3"-butanoyloxybutyloxy)biphenyl ##STR7##
The same procedure as that described in Example 1 was repeated except that (S,S)-2,4-pentanediol was used instead of the (R,R)-2,4-pentanediol. Thus, the synthesis of the objective compound was carried out.
The infrared spectroscopic analysis of the product revealed that the product had the following characteristic absorptions and the product was thus identified as the objective compound:
______________________________________3030 cm.sup.-1 (vw), 2925 cm.sup.-1 (s), 2860 cm.sup.-1 (m),1730 cm.sup.-1 (s), 1605 cm.sup.-1 (s), 1585 cm.sup.-1 (vw),1495 cm.sup.-1 (s), 1470 cm.sup.-1 (m), 1380 cm.sup.-1 (m),1240 cm.sup.-1 (s), 1180 cm.sup.-1 (s), 1105 cm.sup.-1 (m), 820 cm.sup.-1 (s)______________________________________
EXAMPLE 3 (SYNTHESIS EXAMPLE 3)
Synthesis of (1"R, 3"R)-4'-octyloxy-4-(1"-methyl-3"-butanoyloxybutyloxy)biphenyl ##STR8##
A mixture comprising 0.38 g of (1"S, 3"S)-4'-octyloxy-4-(1"-methyl-3"-hydroxybutyloxy)biphenyl, 0.79 g of butyric anhydride and 0.04 g of pyridine was reacted at 100° C. for 3 hours and the obtained reaction mixture was poured into 2 N hydrochloric acid. The obtained mixture was extracted with ethyl ether. The extract was washed with water, dried and freed from the solvent. The residue was purified by silica gel column chromatography using a n-hexane/ethyl ether (9:1) mixture as a developing solvent to obtain 0.36 g of a colorless oil.
The infrared spectroscopic analysis of the oil revealed that the oil had the following characteristic absorptions and the oil was thus identified as the objective compound.
______________________________________3030 cm.sup.-1 (vw), 2925 cm.sup.-1 (s), 2860 cm.sup.-1 (m),1730 cm.sup.-1 (s), 1605 cm.sup.-1 (s), 1585 cm.sup.-1 (vw),1495 cm.sup.-1 (s), 1470 cm.sup.-1 (m), 1380 cm.sup.-1 (m),1240 cm.sup.-1 (s), 1180 cm.sup.-1 (s), 1105 cm.sup.-1 (m), 820 cm.sup.-1 (s)______________________________________
EXAMPLE 4 (SYNTHESIS EXAMPLE 4)
Synthesis of (2"R, 3"S, 1'S, 3'S)-4'-octyloxy-4-[1'-methyl-3'-(2"-chloro-3"-methylpentanoyloxy)-butyloxy]biphenyl ##STR9##
The same reaction as that described in Example 1 was carried out except that 0.18 g of (2R, 3S)-2 -chloro-3-methylpentanoic acid was used instead of the butyric acid. The obtained product was purified by silica gel column chromatography using a n-hexane/ethyl acetate (95:5) mixture as a developing solvent to obtain 0.35 g of a colorless oil.
The infrared spectroscopic analysis of this oil revealed that the oil had the following characteristic absorptions and the oil was thus identified as the objective compound.
______________________________________3030 cm.sup.-1 (vw), 2925 cm.sup.-1 (s), 2860 cm.sup.-1 (m),1740 cm.sup.-1 (s), 1605 cm.sup.-1 (s), 1580 cm.sup.-1 (vw),1495 cm.sup.-1 (s), 1465 cm.sup.-1 (m), 1380 cm.sup.-1 (m),1240 cm.sup.-1 (s), 1175 cm.sup.-1 (s), 1110 cm.sup.-1 (m), 820 cm.sup.-1 (s)______________________________________
EXAMPLE 5 (SYNTHESIS EXAMPLE 5)
Synthesis of (1"S, 3"S)-5-decyl-2-[4'-(1"-methyl-3"-butanoyloxybutyloxy)phenyl]pyrimidine ##STR10##
The same reaction as that described in Example 1 was carried out except that 0.40 g of (1"S, 3"R)-5 -decyl-2-[4'-(1"-methyl-3"-hydroxybutyloxy)phenyl] pyrimidine was used instead of the (1"S, 3"R)-4'-octyloxy-4'(1"-methyl-3"-hydroxybutyloxy)biphenyl. The obtained product was purified by silica gel column chromatography using a n-hexane/ethyl ether (8:2) mixture as a developing solvent and distilled by the use of an Allihn condenser at 218° to 221° C./0.11 mmHg to obtain 0.20 g of a colorless oil.
The infrared spectroscopic analysis of the oil revealed that the oil had the following characteristic absorptions and the oil was thus identified as the objective compound.
______________________________________2920 cm.sup.-1 (s), 2850 cm.sup.-1 (m), 1730 cm.sup.-1 (s),1605 cm.sup.-1 (m), 1585 cm.sup.-1 (s), 1540 cm.sup.-1 (vw),1510 cm.sup.-1 (w), 1460 cm.sup.-1 (w), 1425 cm.sup.-1 (s),1375 cm.sup.-1 (w), 1325 cm.sup.-1 (vw), 1300 cm.sup.-1 (vw),1245 cm.sup.-1 (s), 1170 cm.sup.-1 (s), 1100 cm.sup.-1 (m), 940 cm.sup.-1 (vw), 845 cm.sup.-1 (w) 800 cm.sup.-1 (m)______________________________________
EXAMPLE 6 (USAGE EXAMPLE 1)
In order to evaluate the effect of the liquid crystal composition according to the present invention, the following four compounds were mixed with each other to obtain a matrix liquid crystal composition: ##STR11##
The above matrix liquid crystal composition was sandwitched between two glass plates and the phase of the composition was observed with a polarization microscope to ascertain the following phase transition: ##STR12##
90% by weight of the matrix liquid crystal composition was mixed with 10% by weight of an optically active ester compound of the present invention listed in Table 1 to prepared a liquid crystal composition. The phase transition temperatures of the composition were determined by the use of a polarization microscope in a similar manner to that described above. Further, the liquid crystal composition was injected into a transparent electrode cell of 2 μm thick glass oriented by rubbing and heated to 120° C. to obtain an isotropic liquid. The liquid crystal cell was gradually cooled and examined for the speed of response by applying a rectangular wave of ±15 V and 1 Hz thereto under crossed nicols. Further, the spontaneous polarization was determined by the triangular wave method. The results are shown in Table 1.
It can be understood from the results shown in Table 1 that the optically active ester compound of the present invention induces an SmC* phase to bring about an extremely short response time and a large spontaneous polarization even when it is added to a matrix liquid crystal composition only in an amount of 10%.
EXAMPLE 7 (USAGE EXAMPLE 2)
A matrix liquid crystal composition comprising the following components was prepared in a similar manner to that of Example 6: ##STR13##
90% by weight of the matrix liquid crystal composition prepared above was mixed with 10% by weight of an optically active ester compound of the present invention: ##STR14## to obtain a liquid crystal composition. This liquid crystal composition was examined for phase transition temperatures, speed of response and spontaneous polarization. The results are shown in Table 2.
EXAMPLE 8 (USAGE EXAMPLE 3)
A matrix liquid crystal composition comprising the following components was prepared in a similar manner to that of Example 6: ##STR15##
90% by weight of the matrix liquid crystal composition prepared above was mixed with 10% by weight of an optically active ester compound of the present invention listed in Table 3 to obtain a liquid crystal composition. This liquid crystal composition was examined for phase transition temperatures, response time and spontaneous polarization. The results are shown in Table 3.
As shown in the foregoing Examples, when the optically active ester compound of the present invention is used as a component of a liquid crystal composition, an SmC* phase is induced in the composition, so that the composition exhibits an extremely high speed of response and a large spontaneous polarization. Thus the present invention can provide an excellent ferroelectric liquid crystal composition.
TABLE 1__________________________________________________________________________ Tc - T = 10 τ PsCompound of the present invention SmC* SmA N* Isc (μsec) (nC/cm.sup.2)__________________________________________________________________________ ##STR16## · 25.9 · 50.5 · 58.1 · 330 -2.9 ##STR17## · 32.4 · 46.2 · 57.3 · 320 -4.4 ##STR18## · 32.1 · 46.4 · 57.0 · 320 +4.4 ##STR19## · 33.8 · 48.5 · 57.0 · 700 -0.5 ##STR20## · 27.5 · 44.5 · 56.3 · 380 -3.9__________________________________________________________________________
TABLE 2__________________________________________________________________________ Tc - T = 10 τ PsCompound of the present invention SmC* SmA N* Iso (μsec) (nC/cm.sup.2)__________________________________________________________________________Matrix not used · 59 · 73 · 84 · 330 +2.2liquidcrystalcompositionLiquid crystal composition ##STR21## · 45 · 70 · -- · 280 +8.8Matrix not used · 76.5 · 87.9 · 100.5 · 530 ≈0liquidcrystalcompositionLiquid crystal composition ##STR22## · 63.7 · 72.0 · -- · 380 +3.1__________________________________________________________________________
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An optically active ester compound useful as a component of a ferroelectric liquid crystal composition is represented by the following formula: ##STR1## wherein R is C 1-18 alkyl or C 1-18 alkoxyl; R' is C 1-18 alkyl or C 1-18 haloalkyl; and ##STR2##
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a surface-modified electrode and its use in a bioelectrochemical process in which electrons are transferred directly between an electrode and an electroactive biological material which is capable of accepting or donating one or more electrons. Many such materials are redox species having a reduced state in which they can accept electron(s) and an oxidised state in which they can donate electron(s). Bioelectrochemical processes of the above kind include processes of carrying out enzymatic reactions, especially for oxidising or reducing organic compounds, in which electrons are transferred from the electrode to the enzyme, to a protein with which an enzyme is complexed or to a cofactor. Other bioelectrochemical processes involve using the energy of biological materials, e.g. enzyme-producing bacteria, to donate electrons to an electrode and thereby drive a fuel cell.
The invention is concerned with a process of direct electron transfer, whereby electrons are transferred directly (mediatorlessly) to the electroactive biological material without the intervention, in that transfer, of any other redox species. Typical mediators are redox dyes and cofactors such as NAD(H) and NADP(H). The bioelectrochemical processes with which the invention is concerned involve the adsorption of the electroactive material from solution onto the surface of the electrode, whereat the electron transfer takes place directly between electrode and electroactive material.
2. Description of the Prior Art
A bioelectrochemical process of the above kind was first described in UK Pat. No. 2033428B (National Research Development Corporation). The corresponding U.S. Pat. No. 4,318,784. The patent described a process in which direct electron transfer takes place from a gold electrode to a protein exemplified by a methane mono-oxygenase enzyme derived from Methylosinus trichosporium, an enzyme complex of cytochrome p450, putidaredoxin and putidaredoxin reductase, and cytochrome c. The patent recommends use of 4,4'-bipyridyl or 1,2-bis(4-pyridyl)ethene as a promotor of the electron transfer. Subsequently, I. Taniguchi et al., J. Chem. Soc., Chem. Commun. 1032 (1982) reported 4,4'-dithiopyridine, otherwise known as bis(4-pyridyl) bisulphide, as a promotor. The process is primarily of interest to supply reducing equivalents which re-convert the oxidised form of an enzyme to its reduced form, for the enzyme catalysis of organic oxidation reactions. In other words, organic chemical reactions are driven by supplying electrical energy.
The 4,4'-bipyridyl-like promotor is not a mediator, but appears to be adsorbed onto the electrode surface to provide a suitable interface for attracting the protein. The protein most extensively studied is horse-heart (HH) cytochrome c. HH cytochrome c is known to contain residues of the amino acid lysine in a ring around the heme edge of the protein and it is believed that when HH cytochrome c forms a complex with a redox enzyme, electron transfer takes place via the heme edge. The theory is that the function of the promotor is to attract the heme edge of the cytochrome c to face the electrode. The ε-amino groups of the lysine residues near the heme edge might hydrogen-bond to the N-atom of a pyridine ring nitrogen of the 4,4'-bipyridyl molecule, the other end of which is possibly "perpendicularly" adsorbed on the electrode surface. See, for example, M. J. Eddowes and H. A. O. Hill, Faraday Discuss. Chem. Soc. 74, 331-341 (1982).
UK Pat. No. 2105750B (National Research Development Corporation) describes a bioelectrochemical process of the same kind but using a different type of electrode. Whereas in the specific description of the earlier patent gold electrode was used and the promotor was added to the electrolyte, the second patent uses an electrode incorporating a "binding species" therewithin. The binding species comprises ionic functional groups or non-ionic species giving rise to a dipole. The electroactive biological material has an oppositely charged site close to the electron transfer portion thereof, so that the biological material becomes temporarily bound to the electrode at the charged site. In the particular embodiments disclosed, the electrode is of graphite and the binding species is either an oxidised group produced by surface-oxidation of the graphite or a C 10 -C 30 fatty acid incorporated in the body of the graphite electrode during manufacture. The theory is that the binding species provides COO - or similar groups which, at appropriate pH, attract positively charged NH 3 + groups in the lysine residues of HH cytochrome c. The binding species is therefore similar in its theorised action to a 4,4'-bipyridyl promotor, except that it is apparently attracted to lysine residues by electrostatic rather than hydrogen bonding.
Recently, P. M. Allen et al., J. Electroanal. Chem 178, 69-86 (1984), examined 54 bifunctional organic compounds to assess their ability to promote the direct electrochemistry of horse-heart cytochrome c at a gold electrode. The assessment gave rise to the conclusion that successful promotors are of the general formula X Y, where X represents a group which adsorbs or binds to the gold surface through a nitrogen, phosphorus or sulphur atom, Y represents an anionic or weakly basic functional group which binds to the positively charged cytochrome c protein ionically or by hydrogen bonding, and the wavy line joining X and Y represents a chemical linkage which can be conformationally rigid or flexible, but which must direct the binding group Y outwardly from the surface of the electrode when group X is adsorbed or bound to the electrode. These X Y promotors are termed "surface modifiers" by P. M. Allen et al., and the same terminology will be used hereinafter. Examples of these surface modifiers are 4-mercaptopyridine, 4-mercaptoaniline, 2,3-dimercaptosuccinic acid, thiodiethanoic acid, 3,3'-thiobis(propanoic acid), 2,2'-thiobis(succinic acid), 4,4 'dithiopyridine, dithiobis(ethanoic acid), 2,2'-dithiobis(succinic acid), 3-thiophenethanoic acid acid, sodium monothiophosphate, 1,2-bis(4-pyridyl)ethene, 2,5-bis(4-pyridyl)-1,3,4-thiadiazole, pyridine-4-sulphonic acid and 4-pyridylphosphonic acid. Some of these compounds required pre-activation of the surface of the electrode with 4,4,'-dithiopyridine, followed by polishing the electrode.
Negatively-charged proteins such as rubredoxin and 2[4Fe-4S] ferredoxin do not give electron transfer with a graphite electrode as described above. However, when a multivalent cation such as Mg 2+ is added, they do give electron transfer, F. A. Armstrong et al., J. Amer. Chem. Soc. 106, 921-923 (1984). Clearly, the divalent Mg 2+ cation bridges between the negatively charged species in the electrode and the negatively charged site in the protein.
SUMMARY OF THE INVENTION
It has now been found that certain organic compounds will promote direct electron transfer between an electrode and a negatively charged protein and still further research has produced a class of compounds which, amazingly, are surface modifiers for both positively and negatively charged proteins.
It has now been found that compounds of formula ##STR2## wherein:
the pyridine ring shown is substituted in the 2-, 3-or 4-position by the (methylene)hydrazinecarbothioamide (MHC) group shown;
R 1 represents hydrogen atom(s) or one or two methyl or ethyl groups in the 2-,3- or 4-position (when the said position is not substituted by the (methylene)hydrazinecarbothioamide group shown);
R 2 represents a hydrogen atom or a methyl group;
R 3 represents a hydrogen atom or a methyl group; and
R 4 represents a hydrogen atom or a methyl group.
The compounds of formula (1) having these surface-modifying properties are (pyridinylmethylene)hydrazinecarbothioamides, hereinafter termed "PMHCs", and simple substitution derivatives thereof.
The invention includes electrodes, especially of gold, having a surface modified with a compound of formula (1). It further includes a process of preparing such a modified electrode which comprises adsorbing the compound of formula (1) onto the electrode surface. The use of the surface modifiers in the promotion of electron transfer is within the invention and also covered is a bioelectrochemical process of the kind described above. Such a bioelectrochemical process can be in either direction. Thus it includes a process in which electrons are supplied to an enzyme or to a protein which complexes with an enzyme thereby to drive a reaction, especially an organic reaction, catalysed by the enzyme. In the reverse direction, it covers a fuel cell in which energy from an organic reaction or a biological transformation is harnessed to produce electricity and possibly a useful by-product from the reaction or transformation.
According to a feature of the invention there is provided a bioelectrochemical process in which electrons are transferred directly between an electrode and an electroactive biological material which is not permanently bound to the electrode, said electroactive biological material having an electron transfer portion capable of receiving and donating electrons and also having close thereto a charged region, characterised in that a surface-modified electrode of the invention is used in the process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows d.c. cyclic voltammograms (a) and (b) of electric potential versus current using various test electrodes (i)-(vi) having a modified or unmodified surface and using a negatively charged protein.
FIG. 2 shows d.c. cyclic voltammograms (a) and (b) of electric potential versus current using the same test electrodes (i)-(vi) and another negatively charged protein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred compounds of formula (1) are the PMHCs themselves, these being the compounds in which R 1 , R 2 , R 3 and R 4 are all hydrogen atoms, i.e. of formula ##STR3## wherein the MHC group shown is a 2-, 3- or 4-position substituent of the pyridine ring.
The corresponding (benzenylmethylene)hydrazinecarbothioamides "BHMCs" do not serve as promotor for negatively or positively charged proteins. It is speculated that the PMHC derivatives are adsorbed on the electrode with the plane of the pyridine ring perpendicular to the plane of the electrode surface, whereas the BMHCs appear to be oriented so that the plane of the benzene ring lies "flat" or approximately parallel to the plane of the electrode surface.
The PMHCs, which are known compounds, and their derivatives can be prepared from the aldehyde or ketone and the appropriately substituted or unsubstituted thiosemicarbazide, according to the reaction scheme ##STR4## where R 1 R 2 , R 3 and R 4 and the pyridine ring substitution are as defined above.
P. M. Allen et al., supra, found that in many instances the selectivity of the bonding to the electrode was improved if the electrode was "pre-activated" by polishing it with 4,4'-bipyridyl or 4,4'-dithiopyridine. The polishing appears to block some of the available sites which in some way assists the surface modifier applied subsequently to bind to the surface of the electrode in a way which presents the Y group in a favourable orientation. Such pre-activation is not necessary when using PMHCs, but with some surface modifiers could be helpful in the context of the present invention.
The best test known to the inventors of whether the surface modifiers really do work is to use cyclic voltammetry. A complete cycle of current produced over a range of positive and negative electrode potentials with well defined and separated peaks is characteristically produced in the voltammogram. FIGS. 1 and 2 show such voltammograms and are discussed in the Examples. Well-defined peaks denote "faradaic current", i.e. that the number of electrons being taken from the external circuit is equal to the number transferred from the electrode to the protein in solution and vice versa when the direction of electron transfer is reversed.
The invention is applicable to any positively charged electroactive biological material (EABM), e.g. mammalian cytochrome c or any of the enzymes described in the prior patents referred to. It is also applicable to any negatively charged EABM such as plasto-cyanin, multi-modified cytochrome c, rubredoxin or 2[4Fe-4S] ferredoxin as well as to EABMs approximately neutral in charge, e.g. azurin from Pseudomonas spp. Horse-heart cytochrome c has a Positive charge of 9, cytochrome c 511 (from Pseudomonas aeruginosa) has a negative charge of -1 and cytochrome c 5 is intermediate in its charge, which is believed to be in the region of +4 to 5. All these proteins are usable in the present invention. The EABM can be a protein which forms a redox couple with an enzyme, an enzyme or a cofactor. It need only possess an electron transfer portion to accept and donate electrons from and to the electrode and a charged site in sufficiently close proximity to the electron transfer portion that attraction of the charged site to face the electrode causes the electron transfer portion to become oriented into a favourable configuration with respect to the electrode for the electron transfer to take place. Put more simply, the relative disposition of the electron transfer portion and charged site of the EABM should be effectively similar to that of the lysine group and heme edge in cytochrome c.
Referring to formula (1), the MHC group (whether unsubstituted or methyl-substituted) is preferably in the 3- or 4-position of the pyridine ring. Whereas PMHCs of all three pyridine ring isomers exhibit similar electron transfer characteristics in relation to the EABMs azurin, cytochrome c 551 and cytochrome c 5 , the 2-isomer is markedly inferior to the others when simultaneously HH cytochrome c is used as the EABM and the working electrolyte does not contain anions, such as perchlorate, which prevent formation of hydrogen bonds. It is believed that if the 2-isomer forms a hydrogen bond, as shown in formula (4): ##STR5## the pyridine nitrogen atom lone pair is not free to interact with the cytochrome c, thereby leading to reduce electron transfer properties. If the 2'-position is blocked by a methyl group, i.e. R 2 in formula (1) is CH 3 , however, hydrogen bonding is somewhat disrupted and the performance of the surface modifier is better than that of the corresponding PMHC in which R 2 in formula (1) is hydrogen. When hydrogen bond formation is disrupted by anions the performance of the ring-position isomers tends to become about the same.
The electrode can be of any material compatible with the surface modifier being adsorbed or bound thereon, e.g. of a noble metal such as Pt, Pd, Ag or Au, or of graphite.
The preferred material for the electrodes is gold and it is preferred that the surface of the electrode is cleaned by polishing (to remove any oxide layer on the gold surface) before the electrode is contacted with the surface modifier. An alusmina/water slurry can be used for this purpose.
The surface modifier can be adsorbed onto the electrode in any convenient way, of which simple dipping is preferred. Since only a surface layer of the modifier is required, the requisite extent of adsorption can be produced by dipping the electrode in a solution of low concentration thereof, for example at least 0.007, preferably at least 0.01, more preferably at least 1 millimolar. Any higher concentration up to saturation of the dipping solution could of course be used. The invention is therefore extremely economical in permitting such small concentrations of the surface modifier to be used.
The following Examples illustrate the invention. They show reversible electron transfer between gold or graphite electrodes and a selection of positively charged, overall neutral and negatively charged proteins. The surface modifiers used are 2-PMHC, 3-PMHC, 4-PMHC and derivatives thereof in accordance with the invention, (benzenylmethylene)hydrazinecarbothioamide, hereinafter "BMHC", of formula: ##STR6## and 2-aminoethanethiol, hereinafter "AET" (HS-CH 2 CH 2 -NH 2 ), dithiobisethanamine, hereinafter "DTBE" (NH 2 -CH 2 CH 2 -S-S-CH 2 -CH 2 -NH 2 ) and 4,4'-dithiopyridine otherwise termed bis(4-pyridyl)bisulphide, hereinafter "DPBS", of formula: ##STR7## all for comparative purposes.
EXAMPLES
Materials and methods
Direct current (d.c.) cyclic voltammograms were obtained using an Oxford Electrodes Ltd. potentiostat and recorded on a Bryans 26000 X-Y recorder. First and third cycle and steady state voltammograms were recorded. A 4 mm diameter gold disc working electrode (except in Example 5 where a graphite electrode was used), platinum gauze counter electrode and saturated calomel reference electrode (Radiometer K401) were used in a glass cell having a working compartment approximately 500 μl in volume. Except where otherwise stated the working compartment was filled with a solution of the protein (165 μM), sodium dihydrogen phosphate buffer (20 mM) sodium perchlorate (100 mM) and adjusted to the stated pH, usually 7 or 7.5, with sodium hydroxide. The sodium perchlorate was included to increase the ionic strength of the solution. Before each experiment the working electrode was polished with a 0.3 μm alumina/water slurry on cotton wool and then washed thoroughly with Milli-Q (doubly deionised) water.
Except where otherwise stated, surface modification was performed by dipping the freshly polished gold working electrode for 2 minutes into a 1 mM solution of the surface modifier in the same buffer-perchlorate solution used in the working compartment followed by copious washing with Milli-Q water.
A sweep rate of 20 mV sec -1 was used except where otherwise stated. The potential range used was between +400 mV and -200 mV (vs. SCE) this range being reduced according to the nature of the protein, to the minimum required to produce a cyclic voltammogram. Thus the starting and switching potentials were adjusted to ensure that they caused no distortion of the shape of the cyclic voltammograms: they were normally more than 120/n mV beyond the potentials of the peak anodic and cathodic faradaic currents, n being the number of electrons per molecule oxidised or reduced. For example, for plastocyanin the sweep was over the range +300 mV to -100 mV (vs. SCE) whilst for multi-substituted cytochrome c a range from +350 mV to -100 mV was employed.
3-PMHC was obtained from Lancaster Synthesis Ltd., as was AET, which was obtained as the hydrochloride. DTBE was obtained from the Aldrich Chemical Co. Ltd. as the dihydrochloride salt. BPBS was supplied as Aldrithiol-4, from Aldrich Chemical Co. Ltd., 2-PMHC, 4-PMHC and BMHC were synthesised from their parent aldehydes and thiosemicarbazide using standard methods, see J. Berstein et al., J. Amer. Chem. Soc. 73, 906 (1951). The properties of each compound were in good agreement with those reported, see F. E. Anderson et al., J. Amer. Chem. Soc. 73, 4967 (1951).
All the substituted PMHCs were synthesised from their parent aldehydes and substituted thiosemicarbazides using the same methods as for the unsubstituted PMHCs. The properties of each of the substituted PMHCs were in good agreement with those reported in the literature.
Spinach plastocyanin was isolated according to the method of Borchert et al., Biochem. Biophys. Acta 197, 78 (1970). The oxidised de-salted, product, having a purity ratio (A 275 /A 598 ) of 1.33 or better, was stored in liquid nitrogen in pellet form.
A modified cytochrome c bearing a net negative charge was obtained using the procedure of D. L. Brautigan et al., J. Biol. Chem. 253, 130 (1978). The method involves the modification of lysines by 4-chloro-3,5-dinitrobenzoic acid (CDNB) and yields mono-, di- and multi-substituted carboxydinitrophenyl (CDNP) derivatives of cytochrome c. The multi-substituted fraction was that eluted first from a 5×100 cm CM-32 chromatography column (Whatman Biochemcials Ltd., UK) with 25 mM phosphate buffer at pH 7.8. The multi-substituted fractions (approximately 3 liters) were pooled, adjusted to 0.01 M and applied to a 1×12 cm DE52 column (Whatman Biochemicals Ltd., UK) pre-equilibrated with 50 mM sodium cacodylate-HCl, pH 7.0. Cytochrome c with a net negative charge remained bound at the top of the column whilst a small amount of less extensively modified cytochrome c was not retained by the column and eluted in the void volume. The negatively charged cytochrome c was eluted with 50 mM cacodylate-HCl PH 7.0, 0.5 M NaCl and diafiltered, using an Amicon Ultrafiltration cell with a YM10 membrane, against distilled water. The modified cytochrome was subsequently frozen in liquid nitrogen in concentrated pellet form.
Native cytochrome c was horse-heart Type VI obtained from the Sigma Chemical Co. and was chromatographed on CM-32 to remove de-amidated forms according to the method of D. L. Brautigan et al., in "Methods in Enzymology" 53, Ed. D. Fleicher and L. Packer, Academic Press, New York, pages 128-164.
Cytochrome c 551 was isolated by the method of R. P. Ambler et al., Biochem. J. 131, 485 (1973).
Cytochrome c 5 was isolated by the method of D. C. Carter et al., J. Mol. Biol. 184, 279 (1985).
Azurin was isolated by the method of S. R. Parr et al., Biochem. J. 157, 423-434 (1976).
All other compounds used were of AnalaR grade. All solutions were made up with Milli-Q water and degassed with oxygen-free argon before use. Experiments were undertaken at 25° C. except where otherwise stated.
EXAMPLE 1
The third cycle d.c. cyclic voltammograms were produced for spinach plastocyanin (250 μM) at pH 7.5 and sweep rate of 20 mV sec -1 , using (i) bare gold, (ii) BMHC-modified gold, (iii) PMHC-modified gold, each of the three isomers of PMHC being tested in turn, (iv) bare gold, (v) BPBS-modified gold and (vi) AET-modified gold electrodes. The third cycle voltammograms are shown in FIG. 1 of the drawings.
At bare gold electrodes, FIG. 1(i) and (iv), no faradaic currents were observed. The change in the capacitative charging current due to surface modification (in the absence of the protein) is consistent with the chemisorption of the surface modifiers to the electrode surface and consequent alteration of the interfacial capacitance. BMHC-modified gold (ii) and BPBS-modified gold (v) also showed no faradaic responses. However, in the presence of isomers of PMHC, each of which gave the said voltammogram (iii), and 2-aminoethanethiol-modified gold electrodes (vi), faradaic currents were observed. The electrochemistry of plastocyanin is well-behaved at these surface-modified electrodes (iii) and (vi).
Table 1, which follows Example 3, gives electrochemical data for Examples 1-3. The separation of the CV peak potentials (ΔE pp ) is about 70 mV, consistent with a quasi-reversible one-electron system. It should be noted that, over the range of potentials used to study protein electrochemistry, no faradaic processes are attributable to the surface modifiers; they are thus not acting as redox mediators of electron transfer. The half-wave potential, E 1/2 , of plastocyanin (which is independent of modifier) does not differ significantly from previously reported values. Plots of peak current (i p ) versus the square root of the sweep rate (ν 1/2 ) are linear up to scan rates of 0.1 V sec -1 . Such plots allowed an estimation of the diffusion coefficient (D) and the heterogeneous rate constant (k s ) to be made. These data are given in Table 2, which follows Example 3.
The electrochemistry of plastocyanin at 25° C. is somewhat impersistent, manifest as a decrease in peak currents and an increase in peak separation. At 3° C., the electrochemistry was much more persistent. Addition of surface modifier to the bulk solution also increased the persistence.
Electron transfer between plastocyanin and the PS1 photosystem of plants is known to be sensitive to pH. Changing the pH had a dramatic effect on the electrochemistry of plastocyanin at an AET-modified electrode. At pH 8, the cyclic voltammograms corresponded to those of quasi-reversible electron transfer between the plastocyanin and the electrode. Decreasing the pH led to lower peak currents and an increase in the peak separations. At pH 6.0 and below no faradaic current was detected. It was also observed that the capacitative charging current of the AET-modified electrode (in the absence of protein) is pH-dependent. However, at PMHC-modified gold electrodes quasi-reversible electrochemistry was observed over the whole pH range, 4.5-8.0. (Thin layer electrophoresis confirmed that the PMHCs are electrostatically neutral between pH 4 and 9.)
EXAMPLE 2
Third cycle d.c. cyclic voltammograms were produced for multi-substituted CDNP-cytochrome c (165 μM) at pH 7.0, except for AET (pH 8.0), using the same electrodes as in Example 1. The steady state voltammograms are shown in FIG. 2.
Bare gold (i) and (iv) showed no faradaic current. All the isomers of PMHC (iii) showed quasi-reversible electrochemistry, but with BMHC (ii) there was no faradaic current. The BPBS-modified electrode (v) showed a small reduction faradaic current on the first cycle only. However, the AET-modified electrodes (vi) showed good faradaic responses and the separation of peak potentials of about 70 mV was consistent with quasi-reversible electron transfer.
EXAMPLE 3
D.c. cyclic voltammograms (not shown) were produced for native horse-heart cytochrome c at pH 7.5 or 8 and otherwise under the same conditions and using the same electrodes as in Example 2.
With native cytochrome c, BPBS and all the isomers of PMHC give quasi-reversible protein electrochemistry. At AET- and DTBE-modified gold electrodes, small reduction and re-oxidation currents were seen but no peaks were observed. Native cytochrome c also showed no faradaic responses at bare gold or a BMHC-modified gold electrode.
The following Tables give electrochemical data relating to Examples 1 to 3. The conditions were the same as in those Examples except that for Table 1 pHs of 7.0 to 8.0 were used and in Table 2 the pH of 7.5 was used. (The precise pH within the 7.0 to 8.0 range does not appear to influence the electrochemistry markedly, except in the case of AET, mentioned in Example 1.) At the temperature of 25° C. the electrochemistry of plastocyanin did not persist but that of the other proteins did.
TABLE 1______________________________________Electrochemical data from cyclic voltammograms ofplastocyanin, native HH cytochrome -c and multi-cytochrome -c atgold electrodes, unmodified and surface-modified as described inExamples 1-3.Multi-substitutedNative CDNP-HH cytochrome -c cytochrome -c PlastocyaninSurface ΔE.sub.pp E.sub.1/2 ΔE.sub.pp E.sub.1/2 ΔE.sub.pp E.sub.1/2Modifier (mV) (mV) (mV) (mV) (mV) (mV)______________________________________Bare gold (a) (a) (a)2-PMHC 92 +30 65 +165 70 +1353-PMHC 74 +30 -- -- 72 +1314-PMHC -- -- -- -- 94 +130AET (b) 68 +164 92 +135DTBE (b) 62 +162 100 +135BPBS 68 +30 (c) (a)______________________________________ Footnotes: (a) No protein electrochemistry was observed. (b) Small reduction and reoxidation currents, no peaks observed. (c) Small reduction current on first cycle only.
TABLE 2______________________________________Redox potential, diffusion coefficient and standardheterogeneous rate constant for plastocyanin, multi-substitutedCDNP-cytochrome -c as determined at pH 7.5, 25° C., by cyclicvoltammetry at a gold electrode, surface-modified by 2-PMHC. E.sub.1/2 (mVProtein vs. SCE) D(cm.sup.2 sec.sup.-1) k.sub.s (cm sec.sup.-1)______________________________________Spinach +135 7.5 × 10.sup.-7 4 × 10.sup.-3plastocyaninMulti-substituted +165 7.9 × 10.sup.-7 5 × 10.sup.-3(CDNP) horse-heartcytochrome -cNative horse-heart +30 5.0 × 10.sup.-7 3 × 10.sup.-3cytochrome -c______________________________________
The above Examples demonstrate that only the PMHCs promote good electrochemistry (electron transfer) of the strongly positively charged protein HH cytochrome c and the two negatively charged proteins, the plastocyanin and the multi-modified cytochrome c.
EXAMPLE 4
This Example shows the effect of varying the amount of surface modifier adsorbed on the electrode. The surface modifier used was 3-PMHC and the protein was native HH cytochrome c at a concentration of 175 μM. Scan rate was 100 mV sec -1 .
The relative amount of surface modifier deposited can be expressed in terms of the length of time for which the electrode is dipped in a solution of the surface modifier (provided, of course, that the saturation amount is not reached).
Table 3 below shows the results. It is concluded that 0.0075 mM or 7.5 μM is about lowest reasonable concentration of surface modifier. While one can use less, it is likely to require an unacceptably long dipping time. The larger the value of ΔE pp in Table 3, the less satisfactory the result (the voltammogram is "flatter" indicating that the maximum current in each direction was obtained at potentials which are more widely separated, representing slower electron transfer from electrode to protein and vice versa).
TABLE 3______________________________________Concentration of Dip time Peak to peak separation3-PMHC (mM) (sec) ΔE.sub.pp (mV)______________________________________0.75 15 750.75 5 750.075 5 1300.075 30 1000.075 120 900.0075 5 1600.0075 120 1200.0075 About 1200 120______________________________________
EXAMPLE 5
A polished graphite electrode in which the base plane (plane of the graphite rings) is parallel to the electrode surface was used. The graphite was obtained from Le Carbone GB Ltd. This electrode, unmodified, gave a cyclic voltammogram with HH cytochrome c, probably because there are defects in the surface in which oxidised carbon groups lie (as in UK Pat. No. 2105750B referred to above). Using 200 μM (1.6 mg/400 μl) native HH cytochrome c, the peak separation was 100 mV. When the graphite electrode was surface-modified by dipping in 4-PMHC, the peak separation was reduced to 85 mV, thus demonstrating an improvement.
EXAMPLE 6
This Example illustrates the use of cytochrome c 5 , azurin and cytochrome c 551 . The protein solution was buffered to pH 7.0 in 0.2 M sodium dihydrogen phosphate (without perchlorate). The electrode was dipped in 1 mM 4-PMHC in 0.1 M sodium dihydrogen phosphate (without perchlorate), pH 7.0. Good cyclic voltammograms were obtained. Table 4 shows the half wave potential and peak to peak separations. The results for azurin were the same irrespective of its Pseudomonas origin, i.e. whether from the species putida, aeruginosa or alcaligenes.
TABLE 4______________________________________ Half wave potential Peak to peak separationProtein E.sub.1/2 (mV vs. SCE) ΔE.sub.pp (mV)______________________________________Cytochrome +92.sub.5 83Azurin +70 75Cytochrome c.sub.551 +50 73______________________________________
EXAMPLE 7
This Example illustrates the use of 9 different surface modifiers according to the invention with 3 different proteins. The dipping solution containing the 1 mM concentration of surface modifier was of 0.1 M sodium dihydrogen phosphate (without perchlorate), adjusted with sodium hydroxide to pH 7.0. The working compartment contained the 165 μM protein solution in 0.2 M sodium cacodylate, adjusted with sodium hydroxide to pH 6.0. The peak to peak separations obtained in the cyclic voltammograms are shown in Table 5 below. It will be seen that in the absence of anions which disrupt formation of hydrogen bonds the 4-position isomers are superior to the 3-position isomers which are in turn markedly superior to the 2-position isomers when the protein is the highly positively charged HH cytochrome c. With the other, less highly positively charged, proteins, there is little difference between the ring isomers. Except in the case of the 2'-methyl group of the 2'-isomer, which appears to reduce the postulated hydrogen bonding effect, the introduction of methyl groups had little effect on the performance of the surface modifers.
TABLE 5______________________________________ ##STR8##Ring Native HHiso- cytochrome .sub.-c Cytochrome Azurin-c.sub.551mer R.sup.2 R.sup.4 ΔE.sub.pp (mV) ΔE.sub.pp (mV) ΔE.sub.pp (mV)______________________________________2- H H >250 67 752- CH.sub.3 H 190 63 702- H CH.sub.3 >250 77 883- H H 130 65 753- CH.sub.3 H 115 70 833- H CH.sub.3 115 68 774- H H 75 67 804- CH.sub.3 H 135 65 804- H CH.sub.3 113 67 80______________________________________
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In a bioelectrochemical process in which the electrons are transferred directly, without use of a mediator, such as a redox dye or cofactor, between an electrode and an electroactive biological material, such as an enzyme or a protein, in either direction, rapid electron transfer has previously been achieved between an electrode and the positively charged protein horse-heart cytochrome c by adding a surface-modifier such as 4,4'-bipyridyl or a derivative thereof.
It has now been found possible to promote electron transfer to either a positively or a negatively charged protein using the same surface-modifier for either job, namely a compound of formula ##STR1## wherein: the pyridine ring shown is substituted in the 2-, 3- or 4-position by the (methylene)hydrazinecarbothioamide group shown;
R 1 represents hydrogen atom(s) or one or two methyl or ethyl groups in the 2-,3- or 4-position (when the said position is not substituted by the (methylene)hydrazinecarbothioamide group shown);
R 2 represents a hydrogen atom or a methyl group;
R 3 represents a hydrogen atom or a methyl group; and
R 4 represents a hydrogen atom or a methyl group.
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
FIELD OF INVENTION
The present invention relates to luminaires or more specifically a sealing and physical shock absorbing gasket for a vandal-resistant luminarie.
BACKGROUND OF THE INVENTION
Many existing public locations, both indoor and outdoor, have luminaires installed. Even though these luminaires are intended to benefit the public they are often times an annoyance for a would be vandal or thief. Therefore, luminaires have long have been targeted for disablement or destruction by vandals, thieves, and others seeking to reduce the amount of light present in a given locale. Luminaire electrical component housings and lamps contained within the electrical component housings of such luminaires are typically fragile in construction. Physical impact or even mere jarring can disable a luminaire or even destroy a portion thereof. The damage can occur to the electrical component housing, lamp, lens, or other component thereby extinguishing the light emitted by the luminaire. Attempts have been made to address this problem for those seeking to maintain the functional status of a luminaire in a public place. This has been addressed by constructing armored luminaires which have an armored electrical component housing or by placing the luminaire out of reach to the public. However, the armor has tended to make the luminaire less aesthetic than desired and the locating of the luminaires out of reach often times decreases the ability of the luminaire to light a desired area. The armor and location of the luminaires has also tended to increase maintenance costs associated with keeping the luminaires operational. More recently, vandal resistant luminaires have been constructed of plastics. However, these luminaires have lacked the capability to resist tampering and to provide an aesthetic luminaire as is desired.
Thus a need continues to exist for luminaires to resist the attempts of vandals, would-be thieves, and the like from destroying the luminaire or extinguishing the light emitted thereby while providing adequate light, protection from environmental elements, and a means for maintaining the luminaire without excessive maintenance costs.
SUMMARY OF THE INVENTION
The present invention relates to a gasket for use in a vandal resistant luminaire intended for use in a public area and designed to resist physical damage from impact while providing adequate light, an aesthetic luminaire, and an economic means for maintenance. The luminaire gasket is designed to absorb physical shock placed on the luminaire lens, seal the lens with the electrical component housing and protect the lamp and other internal components from environmental elements.
Preferably the gasket is comprised of extra thick extruded silicon rubber and has a cross-sectional configuration that absorbs physical shock from lens impact while sealing against dust, moisture, and water. The cross-sectional configuration is such that when in a sealing configuration it is expanded providing a seal and when a shock is placed about the lens the gasket compresses wherein it absorbs the shock improving the luminaires resistance to tampering.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a vandal resistant luminaire showing external components thereof;
FIG. 2 is an exploded view of a vandal resistant luminaire showing the placement of a gasket therein;
FIG. 3 is a perspective view of a electrical component housing for a vandal resistant luminaire having a gasket placed about a front rim;
FIG. 4 is a cross-sectional view of an embodiment of a gasket for a vandal resistant luminaire in an expanded configuration;
FIG. 5 is a cross-sectional view of the gasket of FIG. 4 in a compressed configuration;
FIG. 6 is a cross-sectional view of an alternative embodiment of a gasket for a vandal resistant luminaire in an expanded configuration;
FIG. 7 is a cross-sectional view of another alternative embodiment of a gasket for a vandal resistant luminaire in an expanded configuration;
FIG. 8 is a cross-sectional view of yet another alternative embodiment of a gasket for a vandal resistant luminaire in an expanded configuration;
FIG. 9 is a cross-sectional view of an embodiment of a gasket for a vandal resistant luminaire having an open configuration; and
FIG. 10 is a cross-sectional view of an embodiment of a gasket for a vandal resistant luminaire having a solid configuration.
DETAILED DESCRIPTION
The present invention relates to a gasket for use in a vandal resistant luminaire intended for use in a public area and designed to resist physical damage from impact while providing adequate light, an aesthetic luminaire, and an economic means for maintenance. The luminaire gaskets depicted in the various figures are selected solely for the purpose of illustrating the invention. Other and different gaskets may utilize the inventive features described herein. Reference to the Figures showing embodiments are made only for descriptive purposes and are not intended to limit the scope of the claims and disclosure herein.
FIG. 1 shows the external components of vandal resistant luminaire 10 . Rear trim ring 12 covers electrical component housing 14 providing an aesthetically pleasing rear side of luminaire 10 while increasing security of luminaire 10 by providing a smooth outer side surface mounting flush against a wall or ceiling reducing pry and hold points. Electrical component housing 14 has an outer lip 24 visible in fully assembled luminaire 10 between rear trim ring 12 and front trim ring 16 . Front trim ring 16 locks onto electrical component housing 14 and is held in a locked position with locking fastener 19 extending through locking fastener receptacle 21 in front trim ring 16 . Front trim ring 16 holds lens 18 to electrical component housing 14 providing a smooth outer surface for vandal resistant luminaire 10 .
FIG. 2 shows the internal components of vandal resistant luminaire 10 and the placement of gasket 17 therein. Rear trim ring 12 is removed from electrical component housing 14 showing the outer configuration of electrical component housing 14 and cooperation between rear trim ring 12 and outer lip 24 of electrical component housing 14 . Lamp holder assembly 15 attaches within electrical component housing 14 and has lamp socket 20 on a front surface. The front surface of lamp holder 15 is preferably comprised of a reflective material. Front trim ring 16 holds lens 18 to electrical component housing 14 with gasket 17 there between providing a smooth outer surface for vandal resistant luminaire 10 . Gasket 17 is placed about gasket ring 28 , both of which are shown having a continuously round configuration, on electrical component housing 14 . Front trim ring 16 has locking lugs 26 for securing about electrical component housing 14 and locked thereto with locking fastener 19 depending into locking fastener receptacle 21 in front trim ring 16 . Lens 18 has outer lip 22 that cooperates with front trim ring 16 on an outer surface and gasket 17 in an inner surface.
FIG. 3 shows electrical component housing 14 having gasket 17 attached to gasket ring 28 . Within electrical component housing 14 is lamp holder assembly 15 having lamp socket 20 . Preferably, the outer surface of lamp holder assembly 15 is comprised of a reflective material and is attached to electrical component housing 14 with bracket and fastener combinations 23 . The electrical wiring, ballast(s), if needed, and other associated electrical components of luminaire 10 are contained within electrical component housing 14 behind lamp holder assembly 15 . On the outer rim of electrical component housing 14 above outer lip 24 are lug receptacles 34 for receiving locking lugs 26 on front trim ring 16 . Locking fastener 19 is also in the outer rim of electrical component housing 14 within a notch 36 for locking front trim ring 16 onto electrical component housing 14 .
FIG. 4 shows a cross-sectional view of a gasket 17 taken along 4 - 4 of FIG. 3 for vandal resistant luminaire 10 in an expanded configuration. Gasket 17 has hollow interior 17 a and is placed on gasket ring 28 by having gasket ring receiving notch 42 receiving gasket ring 28 . Lower wall 46 of gasket 17 has a raised portion for absorbing physical shock. Inner wall 44 is convex or depends slightly outward to top wall 49 . Top wall 49 is shown as being angled upward toward outer wall 48 providing a sealing surface toward an outer portion of luminaire 10 for sealing with lens 18 . Top wall 49 also has a thickened shock absorbing region 49 a . Outer wall 48 is convex or depends inward so that when a force is placed on top wall 49 outer wall 48 folds inward providing shock absorbing material 48 a and 48 b between electrical component housing 14 and lens 18 . FIG. 5 shows the gasket of FIG. 4 in a compressed configuration. In this configuration outer wall 48 is folded inward providing two additional layers of gasket material 48 a and 48 b between electrical component housing 14 and lens 18 . This inward collapsing wall provides gasket 17 with additional shock absorbing capacity when a physical shock is placed on top wall 49 .
FIG. 6 shows gasket 60 for a vandal resistant luminaire 10 in an expanded configuration. Gasket 60 has a cross-sectional configuration being substantially a mirror image of gasket 17 . Gasket 60 is placed on gasket ring 28 by having gasket ring receiving notch 62 receiving gasket ring 28 . Lower wall 66 of gasket 60 has raised area for absorbing physical shock. Outer wall 64 is convex and depends slightly outward to top wall 69 . Top wall 69 is shown as being angled upward toward inner wall 68 providing a sealing surface toward an inner portion for sealing with lens 18 . Top wall 69 also has a thickened shock absorbing region 69 a . Inner wall 68 is concave and depends inward so that when a force is placed on top wall 69 inner wall 68 folds inward providing shock absorbing material between electrical component housing 14 and lens 18 .
FIGS. 7 and 8 show cross-sectional views of alternative embodiments of a sealing shock absorbing gasket in an expanded configuration for vandal resistant luminaire 10 . FIG. 7 shows gasket 70 placed on gasket ring 28 by having gasket ring receiving notch 72 receiving gasket ring 28 . Lower wall 76 of gasket 70 has raised area for absorbing physical shock. Outer wall 74 and inner wall 78 are both concave and depend inward so that when a force is placed on top wall 79 both outer wall 74 and inner wall 78 fold inward providing shock absorbing material between electrical component housing 14 and lens 18 . Top wall 79 is shown as being substantially flat providing a sealing surface for sealing with lens 18 . Top wall 79 may optionally have a thickened shock absorbing region. Gasket 80 , as shown in FIG. 8 , is placed on gasket ring 28 by having gasket ring receiving notch 82 receiving gasket ring 28 . Lower wall 86 of gasket 80 has raised area with a void space 85 for absorbing physical shock. Outer wall 84 depends slightly inward to top wall 89 and folds inward when gasket 80 is compressed with a force placed on top wall 89 . Top wall 89 is shown as being angled upward toward outer wall 84 providing a sealing surface toward an outer portion for sealing with lens 18 . Top wall 89 has a thickened shock absorbing region. Inner wall 88 is convex and depends outwardly.
FIG. 9 shows gasket 90 for a vandal resistant luminaire 10 in an expanded configuration. Gasket 90 has an open cross-sectional configuration. Gasket 90 is placed on gasket ring 28 of electrical component housing 14 by having gasket ring receiving notch 92 receiving gasket ring 28 . Lower wall 96 of gasket 90 is substantially flat. Side wall 94 depends slightly outward to top wall 99 . Top wall 99 is shown as being curved providing a sealing surface for sealing with lens 18 .
FIG. 10 shows a cross-sectional view of a gasket 100 for vandal resistant luminaire 10 in an expanded configuration. Gasket 100 is placed on gasket ring 28 by having gasket ring receiving notch 142 receiving gasket ring 28 . Inner wall 144 depends slightly outward to top wall 149 . Top wall 149 is shown as being angled upward toward outer wall 148 providing a sealing surface toward an outer portion of luminaire 10 for sealing with lens 18 . Outer wall 148 depends inward so that when a force is placed on top wall 149 outer wall 148 folds inward. Inward collapsing wall 148 provides gasket 100 with additional shock absorbing capacity when a physical shock is placed on top wall 149 .
Preferably the vandal resistant luminaire gasket is comprised of a silicon rubber material. However, other materials having flexing, shock absorbing and sealing properties may be used to construct the gasket. Preferably the gasket is extruded and may have a thickened or even solid cross-sectional configuration providing additional shock absorbing capacity. In an expanded configuration the gasket seals dust, moisture, and water in the environment from the internal components of the luminaire. The sealing shock absorbing gasket can have a multitude of configurations, several of which have been shown.
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A gasket for a vandal resistant luminaire, the gasket is constructed to be disposed between an electrical component housing and a lens wherein the lens is held to the electrical component housing with a front trim ring surrounding an outer portion thereof. The gasket is designed to form a seal between the lens and electrical component housing and absorb physical shock placed on the lens and/or the electrical component housing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of loop antennas, and more particularly to adjustable wristband loop antennas for wristworn receiving devices.
2. Description of the Prior Art
Recent advances in miniaturization of receiver components have made possible the development of wristworn receiving devices, such as wristworn pagers. Various antenna configurations have been developed using loop antennas which have been located within the wristband of the wristworn receiving device. Examples of such wristband antennas are as follows. U.S. Pat. No. 4,754,285 issued to Robitaille and U.S. Pat. No. 4,769,656 issued to Dickey illustrate loop antennas suitable for use in expansion type wristbands. U.S. Pat. No. 4,713,808 issued to Gaskill illustrates a basic wristband loop antenna configuration, which presumably requires retuning for different wrist sizes. U.S. Pat. No. 4,922,260 issued to Gaskill illustrates a wristband loop antenna which presumably must be cut to adjust the length and the corresponding resonance of the antenna to fit the wearer's wrist. U.S. Pat. No. 4,977,614 issued to Kurcbart illustrates an apparatus for adjusting the length of a single segment loop antenna while automatically compensating for the antenna tuning. And U.S. Pat. No. 4,873,527 issued to Tan illustrates a combination ferrite loop and wristband loop antenna arrangement. Such antennas, as described above, are generally suitable for use only at lower operating frequencies, such as below approximately 170 Megahertz. As the operating frequency is increased, such loop antennas can become more difficult to tune, become more directional, and become more difficult to provide an impedance match to the RF amplifier. There is a need to provide a wristband loop antenna structure which is capable of overcoming the deficiencies described above for operating at frequencies in excess of 170 Megahertz.
SUMMARY OF THE INVENTION
A wristworn receiving device suitable for being worn about a wrist comprises a receiver for receiving radio frequency signals on a particular operating frequency, a housing for enclosing the receiver, a first wristband section coupled to the housing and including a first wristband loop antenna portion having a first end coupled to the receiver and a second end coupled to a movable clasp member, and a second wristband section coupled to the housing and including a second wristband loop antenna portion having a first end coupled to the receiver and a second end coupled to a fixed clasp member. The first and second wristband loop antenna portions include capacitive and inductive elements which partially resonate the first and second wristband loop antenna portions at the operating frequency. The second end of the second wristband loop antenna portion is coupled to the second end of the first wristband loop antenna portion and is positioned by the movable clasp member at first and second positions along the second end of the first wristband loop antenna portion so as to form a resonant loop antenna which remains substantially tuned to the operating frequency at the first and second positions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B, and 1C are pictorial diagrams illustrating the construction of the wristband loop antenna in accordance with the present invention.
FIGS. 2A, 2B and 2C are pictorial diagram illustrating the tuning arrangement of the wristband loop antenna in accordance with the present invention.
FIGS. 3a-3d is a pictorial diagram illustrating the electrical components associated with the wristband loop antenna in accordance with the present invention.
FIG. 4 is an electrical schematic diagram of the wristband loop antenna in accordance with the present invention.
FIGS. 5a-5e is a pictorial diagram illustrating the positions utilized in characterizing the wristband loop antenna in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A, 1B and 1C are pictorial diagrams illustrating the construction of the wristband loop antenna in accordance with the present invention. As shown in FIGS. 1A and 1C, the wristband loop antenna comprises two antenna segments constructed as wristband sections 102 and 104. The wristband section 102 comprises a first conducting element 106, an insulating element 108, and a second conducting element 110. In particular, the first conducting element 106 is formed as a generally rectangular sheet from a five mil thick (five thousandths of an inch thick) copper-clad KAPTON™ polyimide film, or other suitable dielectric material. The cladding is preferably two ounce copper laminated to the polyimide film. The insulating element 108 is formed as a generally rectangular sheet from a five mil thick non-clad KAPTON™ polyimide film, or other suitable dielectric material, which is somewhat wider in width and somewhat shorter in length than the first conducting element 106. The second conducting element 110 is formed having a first portion 112 which is generally rectangular, and a second portion 114, contiguous to the first portion 112, which is symmetrically tapered about the midline of the second conducting element 110, the function of which will be described in detail below. The second conducting element 110 is formed from a five mil thick copper-clad KAPTON™ polyimide film, or other suitable dielectric material, having a width somewhat wider than the insulating element 108. The insulating element 108 is positioned and adhesively attached using a pressure sensitive adhesive film to the polyimide film surface of the second conducting element 110. The first conducting element 106 is then positioned with the polyimide film surface facing the insulating element 108 and adhesively attached using a pressure sensitive adhesive film, or other suitable material, to the insulating element 108 thereby forming, as shown in FIG. 1B, the first antenna segment 118 having two conducting surfaces and approximately a fifteen mil thick insulator spaced therebetween. An insulated conductor 116, such as insulated, stranded wire, is then soldered to the conductor surface of the first conducting element 106 to provide electrical connection between the first antenna segment 118 and a receiver located within a housing which may include, among other things, paging decoding circuitry, watch circuitry, and an LCD display for displaying the time and any received messages. The first antenna segment 118 is then molded into a strap 120, using a silicon rubber material, such as BAYSILONE™ LSR2070 manufactured by Mobay Chemical Company or PELETHANE™ manufactured by Dow Chemical Company, or other suitable material.
Returning to FIGS. 1A and 1C, the wristband section 104 comprises a first conducting element 124, an insulating element 126, and a second conducting element 128. In particular, the first conducting element 124 is formed as a generally rectangular sheet from a five mil thick copper-clad KAPTON™ polyimide film, or other suitable dielectric material. The cladding is preferably two ounce copper laminated to the polyimide film. The insulating element 126 is formed as a generally rectangular sheet from a five mil thick non-clad KAPTON™ polyimide film, or other suitable dielectric material, which is somewhat wider in width and somewhat shorter in length than the first conducting element 124. The second conducting element 128 is formed having a first portion 130 which is generally rectangular, and a second portion 132, or tab portion contiguous to the first portion 130, which is symmetrical about the midline of the second conducting element 128. The second conducting element 128 is formed from three mil thick beryllium-copper sheet metal, or other suitable material such as quarter or half hard copper, having a width somewhat wider than the insulating element 126. When a sheet metal other than copper is utilized, the sheet metal should be suitably plated, such as with a tin or gold over nickel over copper plating, to improve the RF conductivity of the sheet metal and to prevent oxidation and improve solderability when required. The insulating element 126 is positioned and adhesively attached using a pressure sensitive adhesive film, or other suitable material, to the second conducting element 128. The first conducting element 124 is then positioned with the polyimide film surface facing the insulating element 126 and adhesively attached using a pressure sensitive adhesive film to the insulating element 126 thereby forming, as shown in FIG. 1B, the second antenna segment 134. An insulated conductor 136 is then soldered to the conductor surface of the first conducting element 124 to provide electrical connection between the second antenna segment 134 and a receiver. A clasp 140 is also soldered or attached by other suitable means, such as spot welding, to the tab portion 132 of the second conducting element 128. The second antenna segment 134 is then molded into a strap 138, as described above.
The first antenna segment 118 and the second antenna segment 134 can also be formed into a wristband using materials suitable for laminating, or also enclosed in other suitable nonconductive materials, such as leather. Also, while specifically described as using a copper-clad KAPTON™ polyimide film for the first conducting elements 106, 124 in the first and second antenna segments 118, 134, and the second conducting element 110 in the first antenna segment 118, it will be appreciated that a sheet metal such as copper, or beryllium-copper can be utilized as well with a corresponding adjustment in the thickness of the insulating elements 108, 126 to compensate for the loss of dielectric thickness due to the removal of the polyimide film. As described above, when a sheet metal other than copper is utilized, the metal should be suitably plated.
Returning to FIG. 1A, the first wristband section 102 is mechanically attached to the device housing 142 using a roll pin 144 with the second conducting element 110 positioned closest to the wrist. A roll pin 146 is also used to mechanically attach the second wristband section 104 to the housing 142 with the second conducting element 128 positioned closest to the wrist. Electrical connection is provided by the insulated conductors 116 and 136, as described above. A slider assembly 122, which can be moveably positioned along the length of the wristband section 102, together with the clasp 140, provides, in one embodiment, an adjustment means providing adjustment of the wristband size in a number of predetermined sized steps is provided, and in a second embodiment the adjustment means provides for the substantially continuous variability in the adjustment of the wristband size when the wristworn device is worn on the wrist. When the wristband segments are implemented as per the first embodiment, the slider assembly 122 is preferably provided with a dimple which is used to engage a plurality of blind holes positioned at regular intervals along the midline on the surface of strap 120, thereby providing for wristband size adjustments in the predetermined steps. When the wristband segments are implemented as per the second embodiment, the dimple on the slider assembly 122 is preferably omitted, thereby providing for wristband size adjustments in a continuously variable manner.
FIGS. 2A, 2B and 2C are pictorial diagrams illustrating the tuning arrangement of the wristband loop antenna in accordance with the present invention. As shown in FIGS. 2A, 2B and 2C, the tuning of the wristband loop antenna in accordance with the present invention is controlled by the amount of overlap of the first wristband section 102 and the section wristband section 104. In particular, as shown in FIG. 2, the antenna tuning is controlled by the overlap of the second conducting element 110 in the first wristband section 102 being proximally positioned between the second conducting element 128 of the second wristband section 104 and the wrist. When the wristworn device is placed on a large wrist, as shown in FIG. 2C, a minimum overlap 202 occurs between second conducting element 110 and the second conducting element 128. When the wristworn device is placed on a small wrist, as shown in FIG. 2B, a maximum overlap 204 occurs between second conducting element 110 and the second conducting element 128. And when the wristworn device is placed on an average wrist, as shown in FIG. 2A, a medium, or nominal wrist, overlap 206 occurs between second conducting element 110 and the second conducting element 128. The amount of overlap of the second conducting element 110 and the second conducting element 128 generates a variable capacitance, as will be described further below, which enables adaptive tuning of the wristband loop antenna. The tapered shape of the second portion 114 of the second conducting element 110 enables continuously tuning the loop antenna over the variation in wrist sizes while maintaining substantially constant antenna tuning. It will be appreciated that other conductor geometries, such as a conductor which is tapered from one edge to the other may be utilized as well to achieve substantially constant antenna tuning. It will be appreciated that the actual range of variation in the overlap being provided is a function of the relative wrist sizes for the group of individuals for which the wrist worn device is intended. Thus a wristband antenna intended for women may have a smaller variation and overall size than that intended for men.
FIG. 3 is a pictorial diagram illustrating the electrical components associated with the wristband loop antenna in accordance with the present invention. As shown in FIG. 3A, the insulated conductor 116 (not shown) and the first conducting element 106 represents a fixed value inductor L1 having an inductance value related to the geometry of the conductors at the particular operating frequency of the receiver. The overlapped metal areas comprising first conducting element 106, insulating element 108 and the first portion of the second conducting element 110 provide a fixed value capacitor C1 having a capacitance value related to the geometry of the overlap of first conducting element 106 and second conducting element 110. The length of the second conducting element 110 represents a fixed value inductor L2 having an inductance value related to the geometry of the conductor segment. That part of the first conducting element 106 which is not overlapped by the second wristband section represents a variable value inductor LV having an inductance value related to the geometry of the non-overlapped conductor segment and is the residual inductance remaining within the overall loop which was not partially resonated by capacitors C1, CV, and C2. The overlapped metal areas comprising the second portion of the first conducting element 114, the wristband cover material, and the first portion of the second conducting element 130 represent a variable value capacitor CV having a capacitance value related to the geometry of the overlap of the second portion of the first conducting element 114 and the second portion of the second conducting element 130. The length of the second conducting element 128 represents a fixed value inductor L3 having an inductance value related to the geometry of the conductor segment. And the insulated conductor 136 (not shown) and the second conducting element 128 represents a fixed value inductor L4 having an inductance value related to the geometry of the conductors at the particular operating frequency. It will be appreciated from the description provided above, the various capacitor and inductor components of the wristband loop antenna are defined in terms of lumped component elements, and other electrical models, such as using distributed component structures could be utilized to define the antenna operation as well.
As shown in FIG. 3B, at maximum overlap of the first and second wristband sections, the variable inductor value LVMIN is a relatively small inductance and can be substantially zero for the inductor LV as described above, while the variable capacitor value CMAX is a maximum capacitance value due to the maximum overlap of wristband section areas. As shown in FIG. 3C, when the overlap of the first and second wristband sections is at the median or midpoint, the variable inductor value LMID is at a median inductance value and corresponds to the added length of the second portion of the second conducting element 110 which is no longer overlapping the second wristband section, while the variable capacitor value CMID is at a median capacitance value corresponding to the geometry of the overlapped wristband section areas. And as shown in FIG. 3D, when the overlap of the first and second wristband sections is at the minimum, the variable inductor value LMAX is at a maximum inductance value and corresponds to the added length of the second portion of the second conducting element 110 which is no longer overlapping the second wristband section, while the variable capacitor value CMIN is at a minimum capacitance value corresponding to the geometry of the remaining overlapped wristband section areas.
In summary, the amount of overlap of the first antenna segment 118 in the first wristband section 102 and the second antenna segment 134 in the second wristband section 104 controls the value of the variable capacitance and inductance presented in the antenna circuit for tuning. As the amount of overlap is increased such as when placed on a smaller wrist, the variable capacitance value is increased while the variable inductance value is decreased, and as the amount of overlap is decreased, such as when placed on a larger wrist, the variable capacitance value is decreased while the variable inductance value is increased, resulting in a net constant impedance value being maintained within the antenna circuit, thereby maintaining a substantially constant tuning of the antenna. Because the first antenna segment 110 is overlapped by the second antenna segment 134 when the receiving device is being worn on the wrist, only a minimum amount of variability in the tuning of the antenna is encountered due to a minimization of the variations in the spacing between the first and second antenna segments 110, 128 and the relative insensitivity of the capacitor value CV to change due to the relatively thick dielectric presented between the first and second wristband sections. It will be appreciated the wristband clamping can be changed to overlap the second wristband section over the first wristband section as well, provided the wristband sections are constantly held in close proximity position.
FIG. 4 is an electrical schematic diagram of the wristband loop antenna in accordance with the present invention. The wristband loop antenna comprises a fixed value inductor L1, a fixed value capacitor C1, a fixed value inductor L2, a variable value capacitor CV, a variable value inductor LV, a fixed value inductor L3, a fixed value capacitor C2 and a fixed value inductor L4, all of which are connected in series. One output 402 of the wristband loop antenna is coupled to the receiver, and in particular, is coupled to one terminal of a fixed value capacitor C3, and one terminal of a fixed value capacitor CS. The other terminal of capacitor C3 is coupled to ground, while the other terminal of capacitor CS is coupled to the input of the RF amplifier 404. Fixed capacitors C3 and CS are used to match the wristband loop antenna into the RF amplifier in a manner well known in the art. The second output 406 of the wristband loop antenna is coupled to a first terminal of a variable capacitor C4. The second terminal of the variable capacitor C4 is coupled to ground. Variable capacitor C4 is used to tune the wristband loop antenna to the particular operating frequency. In the preferred embodiment of the present invention, the wristband loop antenna is tuned with the first and second antenna segments overlapped to approximately the median capacitance value for variable capacitor CV, when the wristworn device is placed on a substantially circular fixture which approximates the conductivity of the human wrist. In this manner, once the antenna has been tuned, variations in tuning encountered between the minimum wrist size and the maximum wrist size are substantially minimized.
It will be appreciated from the description provided above, the tuning of the wristband loop antenna constructed in accordance with the present invention is a function of a number of variables which are dependent upon the actual frequency of operation. The actual variation of the wristband size between a small wrist and a large wrist and the choice of wristband material and thickness determines the variation in capacitor value CV and the inductor value LV to tune the antenna. The actual plate sizes and dielectric thicknesses for capacitors C1 and C2, which are formed as described above, are functions of the operating frequency, the dielectric material utilized and the overall relative inductance of the basic loop antenna structure at the operating frequency. The value for C1 and C2 are selected to resonate the first and second wristband loop antenna segments at a predetermined resonant frequency which will be below the lowest operating frequency, thereby reducing the overall loop inductance. By proper selection of C1 and C2 capacitor values, a variable capacitor C4 having a range, such as on the order of from 1-10 picofarads, will enable tuning the wristband loop antenna over a relatively wide frequency range, such as from 270-290 MHz, while maintaining substantially constant antenna tuning over the complete range of wrist sizes. It will be appreciated that actual capacitor and inductor values are a function of the actual operating frequency and the required match to the RF amplifier, and may be larger or smaller than that described above.
FIG. 5 is a pictorial diagram illustrating some typical test positions utilized in characterizing the wristband loop antenna in accordance with the present invention. It will be appreciated that other test positions may be utilized as well to characterize other aspects of the performance of the antenna when the wristworn device is worn on the wrist, depending upon the degree of characterization which may be deemed necessary. Five typical test positions are shown. FIG. 5A corresponds to a position where the wearer of the wristworn device is facing the transmitting antenna, and has the arm positioned in front of the body, as shown. FIG. 5B corresponds to a position where the wearer of the wristworn device is facing the transmitting antenna, and has the arm positioned by the side of the body, as shown. FIG. 5C corresponds to a position where the wearer of the wristworn device is rotated ninety degrees relative to the transmitting antenna, and has the arm positioned to the side of the body facing the transmitting antenna, as shown. FIG. 5D corresponds to a position where the wearer of the wristworn device is facing the transmitting antenna, and has the arm positioned as if resting "on a table" with the arm pointed toward the transmitting antenna, as shown. And FIG. 5E corresponds to a position where the wearer of the wristworn device is facing the transmitting antenna and has the arm positioned straight out from the body at shoulder height, as shown. TABLE I below provides some typical performance data for a wristworn device operated at a frequency of approximately 280 MHz.
TABLE I______________________________________ FIG. FIG. FIG. FIG.POSITION A B FIG. C D E______________________________________RELATIVE 11 dB 17 dB 16.6 dB 19 dB 11 dBSENSITI- μV/M μV/M μV/M μV/M μV/MVITYCOMPARATIVE 0 dB -6 dB -5.5 dB -8 dB 0 dBSENSITI-VITY______________________________________
As can be observed from TABLE I, the wristworn loop antenna constructed in accordance with the present invention provides not only substantial H-field, or magnetic field, performance as indicated by the performance data for FIG. 5A, but also exhibits substantial E-field, or electric field, performance as indicated by the performance data for FIGS. 5B-5E. As demonstrated, a worst case null of approximately 6 dB (decibels)(B & C) to 8 dB (D) is obtained when the wrist worn device is positioned as shown in FIG. 5D, as compared to an expected null of on the order of 20-25 dB for a conventional loop antenna at the same operating frequency.
In summary, the wristband loop antenna constructed in accordance with the present invention provides improved antenna sensitivity as compared to a conventional loop antenna, while enabling the ability to continuously adjust the size of the wristband about the wrist. The reduction in worst case nulls is due to improved E-field performance which is created by symmetrically positioning conducting elements 106 and 124. The E-field performance is enhanced by varying the aspect ratio as of the width of first conducting elements 106 and 124 compared to the second conducting elements 110 and 128. As the width of the first conducting elements 106 and 124 approach the width of second conducting elements 110 and 128, the E-field performance is reduced, and conversely, as the width of the first conducting elements 106 and 124 are reduced compared to the width of second conducting elements 110 and 128, the E-field performance is enhanced. E-field performance is further enhanced as the frequency of operation is increased. While the description of the wristband loop antenna provided above demonstrates a significant improvement in the antenna efficiency at operating frequencies of 280 Megahertz, it will be appreciated that the antenna configuration disclosed can also provide improved antenna efficiencies at operating frequencies well below and well above the operating frequency indicated, and provide considerable antenna efficiency improvement over prior art wristband loop antennas which were usually limited to operating frequencies generally below 170 Megahertz.
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A wristworn receiving device suitable for being worn about a wrist comprises a receiver (404) for receiving radio frequency signals on a particular operating frequency, a housing (142) for enclosing the receiver (404), a first wristband section (102) including a first wristband loop antenna portion (118) and a movable clasp member (122), and a second wristband section (104) including a second wristband loop antenna portion (134) terminated in a fixed clasp member (140). The first (118) and second (134) wristband loop antenna portions are partially resonated at the operating frequency. The second wristband loop antenna portion (134) is coupled to the first wristband loop antenna portion (118) and is positioned by the movable clasp member (122) at first (204) and second (202 or 206) positions along the first wristband loop antenna portion (118) so as to form a resonant loop antenna which remains substantially tuned to the operating frequency at the first (204) and second (202 or 206 ) positions.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority to Korean Patent Application No. 10-2010-0067412 filed in the Korean Intellectual Property Office on Jul. 13, 2010, the entire contents of which is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a variable compression ratio apparatus. More particularly, the present invention relates to a variable compression ratio apparatus that changes compression ratio of gas mixture in a combustion chamber in accordance with operational conditions of an engine.
2. Description of Related Art
In general, thermal efficiency of heat engines increases when compression ratio is high and when igniting timing increases to a predetermined level in spark ignition engines. However, the spark ignition engines have a limit in increasing the ignition timing because the engines may be damaged by abnormal combustion when the ignition timing is increased at high compression ratio, which necessarily reduce the output power.
A variable compression ratio (VCR) apparatus is an apparatus that changes compression ratio of gas mixture in accordance with operational conditions of the engine. According to the compression ratio apparatus, fuel efficiency is improved by increasing the compression ratio of gas mixture under the low load condition of the engine, and knocking is prevented and the engine output is improved by reducing the compression ratio of the gas mixture under the high load condition of the engine.
In order to achieve the variable compression ratio, an oil chamber is formed inside a bias ring disposed in a small portion of a connecting rod and the bias ring is eccentrically rotated by hydraulic pressure generated by supplying oil into the oil chamber, which has been proposed; however, the variable compression ratio apparatus according to the related art has a problem that the distance from the bias ring to the center of the oil chamber is small, such that pressure for maintaining the position of the bias ring in the oil chamber is largely increased when explosion pressure is applied, and it is difficult to maintain the compression ratio.
Further, there is a problem requiring excessive oil pressure, which is needed to change the compression ratio.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
BRIEF SUMMARY OF THE INVENTION
Various aspects of the present invention are directed to provide a variable compression ratio apparatus having advantages of having an improved structure to efficiently change compression ratio in a cylinder.
In an aspect of the present invention, the variable compression ratio apparatus including an external piston, a piston pin mounted in the external piston, a crankshaft, and a connecting rod pivotally connecting the external piston with the crankshaft, may include an internal piston including a slot and sliding up or down in close contact to an interior circumference of the external piston, wherein the piston pin passes through the slot of the internal piston and the external piston, a latching pin passing through the piston pin and selectively sliding therein, variable sliders disposed to selectively contact one of both ends of the latching pin, at both sides thereof to push the one of the both ends to the opposite side, and a support plate slidably supporting the variable sliders such that the variable sliders reciprocate in perpendicular direction to the length direction of the latching pin, wherein one end of a connecting arm selectively rotating may be connected to the variable slider and a sliding direction of the variable sliders may be controlled by rotation of the connecting arm.
An oil chamber may be formed between the inside of the external piston and the top of the internal piston so as to selectively store oil therein to generate hydraulic pressure, wherein an oil supply channel may be formed in the connecting rod to supply oil to the oil chamber.
A control channel may be formed in the latching pin to receive oil from the oil supply channel formed in the connecting rod and oil in the control channel may be selectively supplied into the oil chamber by reciprocation of the latching pin.
Protrusions may be formed on an inner side of the variable sliders to correspond to the both ends of the latching pin, and the protrusions do not face each other in movement direction therebetween.
The rotary shaft and the variable slider may be connected by the connecting arm, wherein an adaptor integrally rotating with the rotary shaft may be mounted on an external circumferential surface of the rotary shaft, the rotary shaft and the connecting arm may be connected by a first hinge portion of the adaptor, and the connecting arm may be connected with the variable slider by a second hinge portion, such that as the rotary shaft selectively rotates in one direction, the connecting arm reciprocates straight by means of the first hinge portion and the second hinge portion.
A guide rail that guides the variable sliders reciprocating forward/backward may be formed on one side of a fixing block wherein the fixing block fixes the support plate and slidably supports the variable sliders.
The rotary shaft may be operated by a separate vacuum actuator.
An oil supply line may be formed on one side in the internal piston and an oil discharge line may be formed on the other side thereof, wherein an oil discharge hole may be formed through the other side of the internal piston to communicate with an oil chamber through the oil discharge line.
An oil supply hole may be formed through the one side of the internal piston to selectively communicate with a control channel of the latching pin, wherein a first check valve may be disposed in the oil supply line to selectively connect the control channel of the latching pin to the oil chamber and a second check valves may be disposed in the oil discharge line to selectively discharge the oil from the oil chamber to the outside, wherein a sliding pin may be disposed in the oil supply line to slide therein to open the oil supply line such that the control channel fluid-communicates with the oil chamber, when oil may be supplied to a side of the sliding pin.
An elastic member may be disposed at one end of the sliding pin to elastically support the end such that the oil supply line may be closed by the elastic member, when oil may be not supplied to the side of the sliding pin.
Locking protrusions formed to the sliding pin protrude from an external circumferential surface thereof in perpendicular direction to a motion direction of the sliding pin and integrally moves by a motion of the sliding pin, wherein an operational groove may be formed on the external circumferential surface of the internal piston and the locking protrusions protrude through operational holes formed through the operational groove.
A plurality of support protrusions may be formed downwards on the operation grooves in the internal piston and an operational ring having protrusions corresponding to the support protrusions on the interior circumference thereof may be inserted in the operation grooves, wherein the locking protrusions of the sliding pin and the protrusions of the operational ring may be engaged such that, as the sliding pin reciprocates, the operational ring selectively rotates in both directions by the protrusions of the sliding pin and the protrusions of the operational ring may be selectively engaged with the support protrusions in accordance with reciprocating direction of the operational ring.
According to the exemplary embodiment of the present invention, since hydraulic pressure may be selectively released or supplied through the oil chamber formed between the external piston and the internal piston, such that it may be possible to achieve a stable and efficient variable compression ratio.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 2 is a perspective view showing a driving part of the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 3 is an exploded perspective view of FIG. 2 .
FIG. 4 is an exploded perspective view showing an operation unit of the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a connecting rod used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 6 is a perspective view showing a piston pin used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 7 is a cross-sectional view showing when a latching pin has moved to one side from the combination position shown in FIG. 6 .
FIG. 8 is a cross-sectional view when the latching pin has moved to the other side from the combination position shown in FIG. 6 .
FIG. 9 is a view when the operation unit of the variable compression ratio apparatus according to an exemplary embodiment of the present invention operates at a high compression ratio and a low compression ratio.
FIG. 10 is a cross-sectional view when the operation unit of FIG. 9 is at a high compression ratio and a low compression ratio.
FIG. 11 is a cross-sectional view showing a sliding pin at a high compression ratio and a low compression ratio.
FIG. 12 is a perspective view showing a piston used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 13 is a cross-sectional view showing the front and rear sides of the piston used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 14 is a horizontal cross-sectional view showing the piston used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 15 is a front view of FIG. 14 .
FIG. 16 is a perspective view showing a variable slider used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 2 is a perspective view showing a driving part of the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 3 is an exploded perspective view of FIG. 2 .
FIG. 4 is an exploded perspective view showing an operation unit of the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a connecting rod used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 6 is a perspective view showing a piston pin used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 7 is a cross-sectional view showing when a latching pin has moved to one side from the combination position shown in FIG. 6 .
FIG. 8 is a cross-sectional view when the latching pin has moved to the other side from the combination position shown in FIG. 6 .
FIG. 9 is a view when the operation unit of the variable compression ratio apparatus according to an exemplary embodiment of the present invention operates at a high compression ratio and a low compression ratio.
FIG. 10 is a cross-sectional view when the operation unit of FIG. 9 is at a high compression ratio and a low compression ratio.
FIG. 11 is a sliding pin at a high compression ratio and a low compression ratio.
FIG. 12 is a perspective view showing a piston used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 13 is a cross-sectional view showing the front and rear sides of the piston used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 14 is a horizontal cross-sectional view showing the piston used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
FIG. 15 is a front view of FIG. 14 .
FIG. 16 is a perspective view showing a variable slider used in the variable compression ratio apparatus according to an exemplary embodiment of the present invention.
Referring to FIG. 1 to FIG. 4 , a variable compression ratio apparatus according to the exemplary embodiment of the present invention includes a driving part P composed of a rotary shaft 100 , a connecting arm 110 , and a variable slider 120 , and an operation unit F composed of an external piton 200 reciprocating by means of explosion of fuel in a cylinder of an engine and an internal piston 210 sliding in the external piston 200 , wherein the internal piston 210 includes a slot 150 and the piston pin 230 passes through the slot 150 . The slot 150 is larger than the diameter of a piston pin 230 to allow a sliding motion of the internal piston 210 in the external piston 200 .
The rotary shaft 100 is selectively rotated in both directions by an actuator 300 separately disposed outside a cylinder block (not provided with reference numeral).
The actuator 300 may be any device that can operate the rotary shaft 100 , such as a vacuum actuator.
In this configuration, the external piston 200 mounted in the cylinder block is disposed to reciprocate along the inner wall of the cylinder and operated by a crankshaft 400 operating with the external piston 200 , and the external piston 200 and the connecting rod 220 are connected by the piston pin 230 at the upper end of the connecting rod 220 .
Further, a latching pin 240 vertically reciprocating in the piston pin 230 is provided.
Further, a space is defined between the external piston 200 and the internal piston 210 .
That is, the internal piston 210 is disposed to vertically reciprocate in close contact to the inner circumference of the external piston 200 and an oil chamber 212 temporarily storing oil and generating pressure is formed in the space that is defined when the internal piston 210 moves down.
Referring to FIG. 5 , a separate oil supply channel 221 may be formed in the connecting rod 220 to supply oil into the oil chamber 212 through a control channel 242 of the latching pin 240 .
That is, the oil supplied through the oil supply channel 221 selectively communicates with the oil chamber 212 by selectively opening the control channel 241 of the latching pin 240 , in accordance with reciprocation of the latching pin 240 , as explained hereinafter.
That is, as shown in FIG. 7 and FIG. 8 , the control channel 241 is formed in the latching pin 240 , communicates with the oil supply channel 221 and selectively communicates with the oil chamber 212 in accordance with left-right reciprocation of the latching pin 240 , such that the oil flows into the oil chamber 212 .
The latching pin 240 includes check valves 215 and 315 and inner surface of the piston pin 230 includes locking grooves 255 such that check valves 215 and 315 are selectively open by being alternatively engaged into the locking grooves 255 in accordance with left-right reciprocation of the latching pin 240 .
In FIG. 7 , the check valve 215 is configured to control an oil flow of oil supply line 213 such that when the latching pin 240 moves in the left direction, a ball of the check valve 215 is locked to the locking groove 255 and thus the oil supply line 213 opens to supply oil to the oil chamber 212 through oil supply hole 228 formed in the internal piston 210 .
In contrast, in FIG. 8 , the check valve 315 is configured to control an oil flow of oil discharge line 214 such that when the latching pin 240 moves in the right direction, a ball of the check valve 315 is locked to the locking groove 255 and thus the oil discharge line 214 opens to discharge oil from the oil chamber 212 through oil discharge hole 227 formed in the internal piston 210 .
In this operation, the rotary shaft 100 is rotated about the axis by the separate actuator 300 . The actuator 300 may be a vacuum actuator, as described above.
Referring to FIG. 2 and FIG. 3 , two adaptors 101 may be attached to the outer circumferential surface of the rotary shaft 100 .
The pair of adaptors 101 connects a pair of connecting arms 110 with a pair of variable sliders 120 to integrally operate in accordance with rotation of the rotary shaft 100 .
A first hinge portion 102 is formed at one end of each of the adaptors 101 .
The adaptor 101 and the rotary shaft 100 are connected by the first hinge portion 102 , and the connecting arm 110 and the variable slider 120 are connected by a second hinge portion 103 formed at the other ends of the connecting arms 110 .
That is, as the rotary shaft 100 is rotated by the actuator 300 , the connecting arm 110 rotated by the first hinge portion 102 of the adaptor 101 reciprocates straight.
Therefore, the variable slider 120 hinged to the second hinge portion 103 of the connecting arm 110 also reciprocates straight.
In this configuration, the variable slider 120 has a support plate 122 with a guide rail, which assists straight motion, on the outer side.
Further, as shown in FIG. 16 , protrusions 123 are formed on the opposite inner sides of the variable slider 120 .
The protrusions 123 is disposed to correspond to both ends of the latching pin 240 .
Further, both protrusions 123 are positioned without overlapping each other in the front-rear direction.
That is, when both variable sliders 120 are on the same vertical line, opposite to each other, the protrusions 123 are not positioned on the same vertical line, such that as the variable sliders 120 selectively moves forward and backward, the protrusion 123 of any one of the variable sliders 120 presses any one end 242 of the latching pin 240 .
The support plate 122 may have a plate shape that is wide such that ensure a movement distance while guiding the variable slider 120 moving straight along the guide rail.
Further, a fixing block 124 is formed at the lower portion of the support plate 122 to slidably support the variable slider 120 and to fix the support plate 122 .
The fixing block 124 is provided to firmly fix the variable slider 120 and the support plate 122 in the cylinder block, using a connecting member.
The fixing block 124 includes a guide rail 144 such that the variable slider 120 slides thereon.
Referring to FIG. 9 to FIG. 12 , oil flow at a high compression ratio and a low compression ratio in the variable compression ratio apparatus according to the exemplary embodiment of the present invention can be seen.
FIG. 10A and FIG. 12 A show a low compression ratio, where the oil discharge line 214 formed in the internal piston 210 is opened by the check valve 315 and the oil supply line 213 is closed by the check valve 214 by right motion of the latching pin 240 .
That is, since the check valve 315 in the oil discharge line 214 of the internal piston 210 is opened and the check valve 215 in the oil supply line 213 is closed, the oil in the oil chamber 212 is discharged through a discharge hole 232 formed through one side of the internal piston 210 .
In an exemplary embodiment of the present invention, a sliding pin 216 is slidably disposed in the oil supply line 213 and elastically biased by an elastic member 225 . Accordingly, in the low compression ratio, the sliding pin 216 in the oil supply line 213 is moved in the left direction by the elastic member 225 since hydraulic pressure is not supplied in the oil supply line 213 .
Simultaneously, the hydraulic pressure generated in the oil chamber 212 is removed, such that the external piston 200 moves down.
FIG. 10B and FIG. 11B show a high compression ratio, where the oil supply line 213 formed in the internal piston 210 is open by the latching pin 240 .
That is, while the oil is supplied from the oil supply line 213 of the internal piston 210 , the oil discharge line 214 at the other side is closed by the check valve 315 , such that hydraulic pressure is generated in the oil chamber 212 .
In an exemplary embodiment of the present invention, a sliding pin 216 is slidably disposed in the oil supply line 213 and elastically biased by an elastic member 225 . Accordingly, in the high compression ratio, the sliding pin 216 in the oil supply line 213 is moved in the right direction while hydraulic pressure is supplied in the oil supply line 213 as shown in FIG. 11B .
Further, as shown in FIG. 14 and FIG. 15 , an operational protrusion 217 formed to the sliding pin 216 protrudes vertically outward with the motion direction of the sliding pin from the external circumferential surface, surrounding the external circumferential surface of the sliding pin 216 .
Further, an operational groove 218 is formed on the external circumferential surface of the internal piston 210 .
The operational groove 218 has an operational hole 219 formed radially outward through the groove.
In this configuration, the operational protrusion 217 protrudes outside the internal piston 210 through the operational hole 219 and operates with a plurality of locking protrusions 223 formed on the inner circumference of an operational ring 222 , which is described below.
The operational ring 222 is fitted on the external circumferential surface of the internal piston 210 .
Since the operational ring 222 has a ring shape and has the locking protrusions 223 substantially symmetric at both sides, on the interior circumference, as described above.
The locking protrusions 223 selectively rotate in both directions by engaging with each other in accordance with reciprocation of the operational protrusion 217 of the sliding pin 216 .
In this configuration, a support protrusion 224 protruding downward is formed above the operational groove 218 .
That is, as shown in FIG. 16 , as the operational ring 222 is rotated by the operational protrusion 217 of the sliding pin 216 , the locking protrusions 223 of the operational ring 222 are selectively supported by the support protrusions 224 of the operational groove 218 , or engaged with each other in the up-down direction. Therefore, the height changes by the distance ‘d’, such that the compression ratio changes.
According to the variable compression ratio apparatus according to the exemplary embodiment of the present invention, it is possible to stably carry combustion load at a high compression ratio in comparison to the structures of the related art, such that is it possible to stably achieve a compression ratio.
For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
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A variable compression ratio apparatus may include an external piston, a piston pin mounted in the external piston and a connecting rod, including an internal piston including a slot and sliding in an interior circumference of the external piston, wherein the piston pin passes through the internal piston and the external piston, a latching pin passing through the piston pin and selectively sliding therein, variable sliders disposed to selectively contact one of both ends of the latching pin, at both sides thereof to push the one of the both ends to the opposite side, and a support plate slidably supporting the variable sliders such that the variable sliders reciprocate perpendicular to length direction of the latching pin, wherein one end of a connecting arm selectively rotating may be connected to the variable slider and a sliding direction of the variable sliders may be controlled by rotation of the connecting arm.
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FIELD OF THE INVENTION
[0001] The present invention relates to an elevator system, in which at least one elevator car, or at least one lift cage, and at least one counterweight are moved in opposite directions in an elevator hoistway, wherein the at least one elevator car and the at least one counterweight run along guiderails, are supported by one or more suspension-and-traction means, and are driven by a traction sheave of a drive unit. The present invention relates particularly to the one or more suspension-and-traction means, viz. to a method of monitoring the one or more suspension-and-traction means of the elevator system, and to a device according to the invention for executing this method.
BACKGROUND OF THE INVENTION
[0002] In elevator systems it has proved advantageous to use suspension-and-traction means that are composed of at least one electrically conductive steel rope and non-conductive sheath, or of ropes made of special plastics, in which an electric conductor is integrated. By this means, for the purpose of monitoring the individual suspension rope or ropes—also known as cords—a monitoring current can be applied. In the electric circuit so formed, or in several so-formed electric circuits, the current flow or current strength, the voltage, the electrical resistance, or the electric conductivity, is measured and provides information about the intactness and/or degree of wear of the suspension-and-traction means.
[0003] So, for example, the published patent application DE 39 34 654 A1 discloses a serial connection of all of the individual cords and an ammeter, or, instead of an ammeter, an electronic circuit, in which the base resistance of an emitter-connected transistor is measured.
[0004] U.S. Pat. No. 7,123,030 B2 discloses a calculation of the electrical resistance through a measurement of the momentary voltage by means of a so-called Kelvin bridge, and a comparison of the voltage value determined by this means with an input reference value.
[0005] International patent publication WO 2005/094250 A2 discloses a temperature-dependent measurement of the electrical resistance value, or of the electrical conductance, in which the varying ambient temperature, and hence also the assumed temperature of the suspension means, is taken into account, which, particularly in tall elevator hoistways, can greatly vary.
[0006] A further international patent publication, WO 2005/094248 A2, discloses special circuits of the individual cords, to avoid electric fields and to avoid orthogonally migrating ions between the individual cords.
[0007] A European patent publication, EP 1 275 608 A1, of an application by the same applicant as for the present application, discloses a monitoring of the sheath by application to the cords of a plus-pole of a source of direct current, so that in the case of a damaged sheath, a mass contact occurs.
[0008] However, disadvantageous in all of these known monitorings of the suspension-and-traction means is that the information about the signs of wear, or about the prevailing anomalous state of the suspension-and-traction means, is present only as an overall result. In particular, cross-connections (short circuits) between cords greatly falsify the overall result.
SUMMARY OF THE INVENTION
[0009] An objective is therefore now to eliminate the said disadvantages of conventional monitoring devices, and to propose a monitoring device for suspension-and-traction means that delivers more accurate and qualitatively classifiable information about its state, thereby achieving a higher level of safety for the elevator system, and avoiding cost-intensive excessively early replacements of the suspension-and-traction sheaves.
[0010] A fulfillment of the objective consists in the first place in the arrangement of an electric circuit that can be applied to the suspension-and-traction means and contains at least two electric resistors, or resistance elements, which possess different resistance characteristics. In the individual case, this can be the resistance value itself, in principle, however, also the tolerance, the maximum power loss, the temperature coefficient, or, taking the same into consideration, the breakdown voltage, the stability, the (parasitic) inductance, the (parasitic) capacity, the noise, the impulse stability, or combinations thereof.
[0011] A first variant of a corresponding arrangement thus foresees a suspension-and-traction means that possesses at least one conductive cord. This suspension-and-traction means is largely sheathed, advantageously with an electrically insulating material such as, for example, rubber or a polyurethane. Connected to each of the conductive ends of the cord are mutually differing resistors. Additionally or alternatively, a further resistor, which differs again from the first two mutually differing resistors, is arranged on a contact point which is passed over by the suspension-and-traction means when in operation.
[0012] This contact point can, for example, be any return pulley, whether a return pulley that is arranged locationally-fixed in the elevator hoistway, or the, or one of the, return pulley(s) of the counterweight or of the elevator car. As a contact point, which is passed over by the suspension-and-traction means, a so-called retainer can also be considered, i.e. an anti-derailer, such as return pulleys usually have. Also, diverter pulleys of the counterweight, or of the elevator car, and in principle also the traction sheave, as well as metallic hoistway components, can be considered. The contact point can be a metallic surface, which, for example, is coated with a highly conductive material, such as copper or brass. Also brush contacts, in the form of, for example, carbon fiber brushes, copper brushes, or similar, can be used. The use of brushes has the advantage that the brushes enter into close contact with a surface of the suspension-and-traction means, i.e. that they, for example, exactly follow a contoured, or formed, surface, so that the entire surface is contacted. However, of primary importance is that the contact point is conductive, and advantageous that it can be grounded—in the case of operation of the monitoring device with direct current—or that a voltage can be applied to the contact point—in the case of operation of the monitoring device with alternating current—and that a contact with the conductive part, or conductive parts, of a suspension-and-traction means is possible in principle if this conductive part of the suspension-and-traction means comes into contact with this contact point.
[0013] This last-mentioned contact between the contact point, for example the return pulley, and the conductive part or conductive parts of the suspension-and-traction means can arise when, for example, individual wires of the cord break, and subsequently penetrate through the sheath. These broken wires touch against the contact point and thus, during the time of their touching, create an electric contact. Thus, by an analysis of the resulting total resistance, or of a corresponding current characteristic, both a discontinuity of a cord, a cross-current or a short circuit between cords, or damage to the sheath, or penetration of individual wires can be detected.
[0014] In an independent solution, this contact between the contact point and conductive parts of the suspension-and-traction means can also be used alone as an indication of damage to the suspension-and-traction means. In this solution, it is even possible to dispense with a resistor, except when a plurality of different resistors is arranged at different contact points. In an advantageous variant embodiment, this contact point is a sliding contact, or a contact point that is, for example, arranged at a small distance from the suspension-and-traction means. This contact point can be any part of the elevator system that the suspension means passes over. This can be, for example, a machine console in the vicinity of the drive machine, or it can be a component part of the car, or it can also be a protective guard or retainer. This contact point is advantageously arranged at a distance ranging from about 1 mm to 15 mm. In an advantageous embodiment, this distance can be set. Achieved by this means is that only true damage to the suspension-and-traction means results in a contact, while small signs of wear are ignored. The contact point is self-evidently embodied electrically conductively.
[0015] Alternatively, the known contact between the contact point, for example the return pulley, and the conductive part, or conductive parts, of the suspension-and-traction means can also be realized, in that, for example, the conductive cord of the suspension-and-traction means is not completely, but only largely, sheathed with non-conductive plastic. Contiguous conductive sections, or even complete parts of the circumference of the cross section, remain free, which extend over the entire length of the suspension-and-traction means, and can come into electrical contact with the return pulley. A further possibility for creating the contact between the cord and the return pulley, or between the contact point and the third resistor, is the integration of conductive strands in the sheath of the suspension-and-traction means. In principle, also a suspension-and-traction means with a conductive sheath is possible, but which then preferably has an insulation layer between the conductive cord and the conductive sheath.
[0016] A further variant foresees a suspension-and-traction means that has a plurality of parallel-running conductive cords. Also this suspension-and-traction means is largely sheathed. Connected to each of the conductive ends of the cord are mutually differing resistance elements, or resistors with specific characteristics, that are assigned to the individual cords. Arranged additionally if required is a single further resistor, which differs again from the other resistors, which, as explained above for the example of a single cord, is arranged on a contact point that is passed over by the suspension-and-traction means when in operation.
[0017] The mutually differing resistances, or resistance elements, that are arranged at the ends of the conductive cord and/or at the ends of the suspension-and-traction means are preferably integrated in contacting elements, as disclosed, for example, in European publication EP 127 56 08 A1. The contacting elements that are published in that document can be arranged not only at the ends of the suspension-and-traction means, but optionally also in between. Further contacting elements, in which the two mutually differing resistors at the ends of the conductive cord, and/or at the ends of the suspension-and-traction means, can preferably be integrated, are, for example, disclosed in the publication documents WO 2005/094249 A2, WO 2005/094250 A2 and WO 2006/127059 A2. The differing resistance elements can also be connected to the ends of the suspension-and-traction means, or integrated in these ends. Other arrangements of the resistors are also possible. Hence, they can be integrated in the connection conductor between the contacting element and a corresponding measurement apparatus.
[0018] The mutually differing resistors or resistance elements are connected with a measurement apparatus, or with a corresponding source of electric current, in such manner that, depending on the respective fault possibility, certain total resistances, current strengths, or—with constantly maintained current source—specific voltages result in the overall circuit. The respective measurement values that are obtained can thus be assigned to a respective incidence of damage. The measurement can be interrogated permanently, as well as at intervals, or only as required before and/or during each travel as a corresponding condition for release of a travel.
[0019] Further, variant embodiments of a such a monitoring device are realizable which, whether in combination with only one, or more than one, cords, and the corresponding number of mutually differing resistors, in case of need have not only one contacting point, over which the suspension-and-traction means passes, but also in case of need can be embodied with a plurality of contacting points.
[0020] As already stated, respective instances of damage can be cord-breakage, cross-circuit (short circuit between two cords), breakthrough, or a combination thereof.
[0021] In principle, with a monitoring device that is embodied in this manner, it is possible to determine the “quality” of an impending cord-break, since the specific resistance of a single cord increases when its cross-sectional area decreases due to increasing breakage of the individual strands. It is, however, preferable to select the mutually differing resistors at the ends of the cords with a magnitude that is a factor greater than the specific resistance of the cord, this factor lying in a range from 500 to 1500, but preferably having a value of approximately 1000. In this manner, a reliable independence of the measurement signal from the mutually differing resistances of the specific resistance of the cord is assured, which varies not only as a function of the cross-sectional area, but also in response to temperature differences which, in a tall elevator hoistway, can be considerable.
[0022] Because in an alternative, in addition to registering the total resistance of the at-least two mutually differing resistors, arranged in between is a contact point to a third resistor, which differs again from the at-least two resistors, it is possible to localize a cord-break, a cross-circuit, or a breakthrough of a cord, to a contact point or a combination thereof. The localization can take place in relation to the cord in question, or it can take place in relation to control data of the elevator system, and to an instant in time of the contact registration at the contact point. This takes place on the basis of the known information, where the contact point is arranged fixed, and/or the known elevator-car position, and/or a time measurement from putting the elevator system into travel, so that, based on the operating speed of the elevator system, the distance traveled by the suspension-and-traction means is calculable. This known, or calculated, position information is compared with the occurrence of a measurement signal at the third resistor, which is arranged in the contact point, or with the occurrence of a change in the measurement signal of this third resistor, and the occurrence of a change in the measurement signals in the at-least two first resistors, and thereby gives the position of an incidence of damage in the suspension-and-traction means. Preferably, the registering and/or calculation of these described values takes place with the aid of a processor, and automatically, and can be displayed on a display or monitor. The processor is preferably further able to store incidences of damage, and thereby to create a damage-accumulation picture.
[0023] Particularly in a monitoring device of this type for a suspension-and-traction means with a plurality of cords, and/or in a corresponding elevator system, it is possible, also preferably by means of the aiding processor, to evaluate the extent of the damage of the entire suspension-and-traction means in relation to the number of damaged spots, and in relation to the extent of a respective individual damaged spot, and thereby to issue a graded warning message. It can be realized, for example, that a suspension-and-traction means with, for example, 12 cords, of which one is broken, or in one of which a cross-circuit occurs only rarely and with low intensity, can still be used for a defined period of time without reservation. This defined safe period is registered by the processor and further shortened, or results in a standstill of the elevator system, if the extent of the damage should correspondingly increase, and/or a further incidence of damage should additionally occur.
[0024] By way of example, the following table shows examples of measurement values and incidences of damage that can occur. The following Table 1 shows possible measurement values of the total resistance in an exemplarily assumed example circuit of a monitoring device according to the invention for two cords A and B. Arranged at the one end of the first cord A is, for example, a resistor of 1 ohm, and at the other end of this first cord A is, for example, a resistor of 1.1 ohms. Arranged on the second cord B are, for example, identical resistors, but arranged mirror-inverted, i.e. at the one end of the second cord B is, for example, a further resistor of 1.1 ohms, and at the other end of this second cord B is, for example, a further resistor of 1 ohm. Arranged at the contact point (P), over which the suspension-and-traction means passes, is, for example, a fifth resistor, of 1.5 ohms. Assumed as voltage source is a direct-current source with a voltage of, for example, 1 volt.
[0025] Possible measurement values of the total resistance are therefore—
[0000] TABLE 1 Incidence of damage Cord break Cross- None A B A + B circuit None 1.050 2.100** 2.100** ∞** A-B 1.048 —** —** —** A-B (before break) — 1.624** 1.524** 2.200** A-B (after break) — 1.524** 1.624** 2.000** A-P 0.939 —** 1.700** —** A-P (before break) — 1.162** —** 2.600** A-P (after break) — 2.100** —** ∞** B-P 0.919 1.635** —** —** B-P (before break) — —** 1.141** 2.500** B-P (after break) — —** 2.100** ∞** A-B-P 0.912* —** —** —** A-B-P (before break) —* 1.158** 1.124** 2.024** A-B-P (after break) —* 1.388** 1.488** ∞**
where the measurement values marked with * are, for example, only a warning, and the measurement values marked with **, on the other hand, are followed by a shutdown of the elevator system. Possible measurement values of the current strength measured in an ammeter are—
[0000]
TABLE 2
Incidence of damage
Cord break
Cross-
None
A
B
A + B
circuit
None
0.952
0.476**
0.476**
0.000**
A-B
0.955
—**
—**
—**
A-B (before break)
—
0.616**
0.656**
0.455**
A-B (after break)
—
0.656**
0.616**
0.500**
A-P
1.064
—**
0.588**
—**
A-P (before break)
—
0.861**
—**
0.385**
A-P (after break)
—
0.476**
—**
0.000**
B-P
1.088
0.612**
—**
—**
B-P (before break)
—
—**
0.876**
0.400**
B-P (after break)
—
—**
0.476**
0.000**
A-B-P
1.096*
—**
—**
—**
A-B-P (before break)
—*
0.863**
0.890**
0.494**
A-B-P (after break)
—*
0.720**
0.672**
0.000**
[0026] Also in a monitoring device that is intended for suspension-and-traction means with a plurality of cords, the resistance elements, and/or the resistors, are preferably arranged mirror-inverted. In other words, in the case of three cords, the mutually differing resistors at the one adjacent ends of the cords have the characteristics x, y, z, while the resistors at the other adjacent ends of the cords have the characteristics z, y, x. The sum of the two resistors that are arranged in this manner on a single cord remains constant. Also, the sum of the resistors that are arranged in parallel at the one ends, preferably in one single first contacting element for all of the cords, and/or the sum of their characteristics x+y+z, is hence identical to the sum of the resistors that are arranged in parallel at the other ends, also preferably in one single second contacting element for all of the cords, and/or to the sum of their characteristics z+y+x. This does not impair the usability of the measurement results that are obtained, and brings the advantage of less expensive series manufacture.
[0027] To avoid falsification of the measurements, which can take place continuously, hence also during standstill of the elevator system, only during a travel, and/or before a travel, it is foreseen to conduct static charges of the elevator system away through a grounding, either continuously, or at least before a measurement takes place.
[0028] The disclosed monitoring devices are preferably combinable with a reverse-bending counter, so that a further information flows into the—preferably processor-aided—monitoring device, and hence the detection of the need for replacement of a suspension-and-traction means becomes even more reliable.
[0029] So far in the present application, mutually differing resistance elements have been disclosed. Instead of with resistors, a monitoring device is, however, also additionally, or entirely, realizable with other electronic components, for example with capacitors and coils. Here, on application of an alternating current, preferably the frequency, the inductance, the capacity, or combinations thereof, are measured.
[0030] Hence, in what follows below, an arrangement and a measurement of a plurality of mutually differing “resistance elements” is claimed, which as generic term can comprise the said electronic components. The measurement can relate to the following current parameters: to the resistance and/or to a resistance characteristic that is listed above, to the current strength, to the voltage, to the frequency, to the inductance, to the capacitance, or to a combination thereof.
[0031] In summary, such a monitoring device brings the following advantages:
[0032] In contrast to a simple continuity test, the measurement values are quantifiable and qualifiable, and hence, more precise, and graded warning messages can be generated.
[0033] The damaged points can be localized in the entire length of the suspension-and-traction means.
[0034] A cumulative damage picture can be created.
[0035] The measurement values are largely independent of the specific resistance of a cord.
[0036] Despite the presence of a possible cross-circuit, a cord-break remains detectable.
[0037] The low number of only two connection points due to the combined contacting elements.
DESCRIPTION OF THE DRAWINGS
[0038] The invention is explained in greater detail symbolically and exemplarily by reference to figures. The figures are described interrelatedly and overall. Identical reference symbols indicate identical components, reference symbols with different indices indicate functionally identical or similar components. Shown are:
[0039] FIG. 1 is a diagrammatic illustration of an exemplary elevator system with a monitoring device for the suspension-and-traction means according to the state of the art;
[0040] FIG. 2 is a diagrammatic illustration of a first variant embodiment of a monitoring device for a suspension-and-traction means with a cord;
[0041] FIG. 2 a is a schematic illustration of a second variant embodiment of a monitoring device for a suspension-and-traction means with two cords, at the same time illustrating a cross-circuit between the two cords, and an impending cord break of a cord;
[0042] FIG. 3 is a diagrammatic illustration of another variant embodiment of a monitoring device for the suspension-and-traction means; and
[0043] FIG. 4 is a diagrammatic illustration of a further variant embodiment of a monitoring device for the suspension-and-traction means.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.
[0045] FIG. 1 shows an elevator system 100 as known from the state of the art, for example in the 2:1 roping arrangement that is shown. Arranged movably in an elevator hoistway 1 is an elevator car 2 , which is connected via a suspension-and-traction means 3 to a movable counterweight 4 . In operation, the suspension-and-traction means 3 is driven by a traction sheave 5 of a drive unit 6 , which is arranged in a machine room 12 in the top area of the elevator hoistway 1 . The elevator car 2 and the counterweight 4 are guided by means of guiderails 7 a or 7 b respectively, and 7 c , which extend over the height of the hoistway.
[0046] With a hoisting height h, the elevator car 2 can serve a top hoistway door 8 , further hoistway doors 9 and 10 , and a bottom hoistway door 11 . The elevator hoistway 1 is formed of hoistway side-walls 15 a and 15 b , a hoistway ceiling 13 , and a hoistway floor 14 , arranged on which latter is a hoistway-floor buffer 19 a for the counterweight 4 , and two hoistway-floor buffers 19 b and 19 c for the elevator car 2 .
[0047] The suspension-and-traction means 3 is fastened to the hoistway ceiling 13 at a locationally-fixed fastening point or suspension-means hitch-point 16 a , and passes parallel to the hoistway side-wall 15 a to a suspension pulley 17 for the counterweight 4 , from there back over the traction sheave 5 to a first return and suspension pulley 18 a , and to a second return and suspension pulley 18 b , passes under the elevator car 2 , and to a second locationally-fixed fastening point or suspension-means hitch-point 16 b on the hoistway ceiling 13 .
[0048] Arranged in the vicinity of the first locationally-fixed fastening point or suspension-means hitch-point 16 a , and in the vicinity of the second locationally-fixed fastening point or suspension-means hitch-point 16 b , are respective first and second contacting elements 20 a and on the respective ends of the suspension-and-traction means 3 . Applicable to the contacting elements 20 a and 20 b is a symbolically drawn test circuit 23 , with a test-current IP, with which, for example, a simple continuity test of the suspension-and-traction means 3 is realizable to function as a monitoring device 200 .
[0049] FIG. 2 shows diagrammatically a monitoring device 200 a in an elevator system 100 a . Connected to the ends of a suspension-and-traction means 3 a , which consists essentially of a cord 21 and a sheath 22 that largely surrounds this cord 21 , are contacting elements 20 c and 20 d respectively. These contacting elements 20 c and 20 d preferably each have integrated in them a resistor R 1 , R 2 respectively, to which a test circuit 23 a , with a voltage source Ua and a test-current IPa, can be applied. Further, this test circuit 23 a has a grounding 24 and a measurement apparatus 25 , as well as an optional connection to a contact point P—for example a return pulley, over which the suspension-and-traction means 3 a passes—with a third resistor R 3 . The resistors R 1 -R 3 have mutually differing current and resistance characteristics so that, depending on a respective incidence of damage, the measurement apparatus 25 measures a classified measurement value that allows a diagnosis, and/or a graded warning message, and/or a shutdown of the elevator system 100 a . The test circuit 23 a can alternatively also be passed only over a contacting of the ends of the cord 21 and the contact point P. In this manner, damaged points in the suspension-and-traction means can be easily detected. The grounding 24 can also take place at another suitable point. So, for example, the contact point P can be connected directly to ground. By this means also, a plurality of contact points can be defined in the elevator system, each of which alone can detect defective spots in the suspension-and-traction means. Preferably, the registering and/or calculation of these described values takes place with the aid of a processor 30 , and automatically, and can be displayed on a display or monitor. The processor 30 is preferably further able to store incidences of damage, and thereby to create a damage-accumulation picture.
[0050] Symbolically shown in FIG. 2 a is a monitoring device 200 a ′ in an elevator system 100 a ′. In contrast to the monitoring device 200 a and the elevator system 100 a of FIG. 2 , a suspension-and-traction means 3 ′ has two cords 21 ′ and 21″ which are surrounded by a sheath 22 ′. A corner and/or a side of the elevator car 2 is shown in perspective and symbolically so that, for example, it can be seen that the suspension-and-traction means 3 ′—and preferably a second, not further shown suspension-and-traction means passes on the opposite side of the elevator car 2 —passing under the elevator car 2 over two return and/or suspension pulleys 27 a and 27 b . These return and/or suspension pulleys 27 a and 27 b form two optionally available contact points P 1 and P 2 , which—shown symbolically—are connected to resistors RP′ and RP″ respectively.
[0051] As already disclosed, at their respective ends, the cords 21 ′ and 21″ are preferably also advantageously connected to resistors RCa and RCa′ for the cord 21 ′, and to resistors RCb and RCb′ for the cord 21 ″. The characteristics of the resistors RCa, RCa′, RCb and RCb′, as well as optionally the resistors RP′, RP″, all mutually differ, or the resistors RCa, RCb and RCa′, RCb′ at the ends of the cords 21 ′ and 21″ are arranged mirror-inverted in relation to their characteristics. In other words, the characteristics of the resistors RCa and RCb′ and/or RCb and RCa′ can also be identical. The ends of the suspension means are connected via the respective resistance elements RCa and RCb′ and/or RCb and RCa′ to the measurement apparatus 25 ′.
[0052] Furthermore, in this FIG. 2 a , at the optional contact point P 1 , the incidence of damage of a cross-circuit Qsch is represented symbolically, in that it is outlined that the cords 21 ′ and 21 ″ no longer sit at a distance from each other in the sheath 22 ′ but, for example, through a sheath 22 ′ that has become damaged, become so close to each other that they enter into contact with each other.
[0053] The incidence of damage of an impending cord break Cb is symbolically shown at the also optional contact point P 2 . The cord 21 ′ begins to unravel its individual strands 26 that protrude from the sheath 22 ′ and thereby cause a contact at the return or suspension pulley 27 b , or at its support. Self-evidently, monitoring of the contact points P 1 , P 2 in the manner shown can also take place without resistors RCa, RCa′, RCb and RCb′.
[0054] Shown diagrammatically in FIG. 3 is another variant embodiment of a monitoring device 200 b for an outlined elevator system 100 b . A suspension-and-traction means 3 b has four cords 21 a - 21 d which are jointly surrounded by a sheath 22 a . Arranged at the respective ends of each of the cords 21 a - 21 d are contacting elements 20 e and 20 f . Integrated in each of these contacting elements 20 e and 20 f are four resistors R 1 ′, R 3 ′, R 5 ′, R 7 ′ and R 2 ′, R 4 ′, R 6 ′, R 8 ′ respectively, which are connected to a test circuit 23 b with a voltage source Ub, a test-current IPb, a grounding 24 ′, and a measurement apparatus 25 a . Furthermore, an optional contact point P′ with a resistor R 9 ′ is connected to the test circuit 23 b.
[0055] The resistors R 1 ′-R 9 ′ all have different current characteristics, or are optionally arranged mirror-inverted. In other words, for example, the resistor R 1 ′ can have a current characteristic w, the resistor R 3 ′ a current characteristic x, the resistor R 5 ′ a current characteristic y, and the resistor R 7 ′ a current characteristic z, while the resistor R 2 ′ has the current characteristic z, the resistor R 4 ′ the current characteristic y, the resistor R 6 ′ the current characteristic x, and the resistor R 8 ′ the current characteristic w. The sums w+z, x+y, y+x, z+w and also w+x+y+z at the one adjacent ends of the cords 21 a - 21 d , and z+y+x+w at the other adjacent ends, are identical. The current characteristic of the resistor R 9 ′ is different than w, x, y or z.
[0056] Shown diagrammatically in FIG. 4 is a further variant embodiment of a monitoring device 200 c for an outlined elevator system 100 c with a suspension-and-traction means 3 c . The suspension-and-traction means 3 c has 12 cords 21 a ′- 211 ′, which are all jointly surrounded by a sheath 22 b . Arranged at the one adjacent ends of the cords 21 a ′- 21 l ′ is a contacting element 20 g , in which resistors R 1 ″, R 3 ″, R 5 ″, R 7 ″, R 9 ″, R 11 ″, R 13 ″, R 15 ″, R 17 ″, R 19 ″, R 21 ″ and R 23 ″ are preferably integrated, each individual resistor being assigned to one of the cords 21 a ′- 21 l ′. Arranged at the other adjacent ends of the cords 21 a ′- 21 l ′ is a second contacting element 20 h , in which, similar to the first contacting element 20 g , resistors R 2 ″, R 4 ″, R 6 ″, R 8 ″, R 10 ″, R 12 ″, R 14 ″, R 16 ″, R 18 ″, R 20 ″, R 22 ″ and R 24 ″ are preferably integrated, each of which is also assigned to one of the cords 21 a ′- 211 ′.
[0057] Similar to FIG. 3 , the resistors R 1 ″-R 24 ″ are connected to a test circuit 23 c with a test-current IPc. The test circuit 23 c has further a voltage source Uc, a grounding 24 ″, and a measurement apparatus 25 b . Also connected to the test circuit 23 c is again an optional contact point P″ with a resistor R 25 ″.
[0058] Also similar to FIG. 3 , the resistors R 1 ″-R 23 ″ with odd reference numbers in relation to their current characteristics are preferably arranged mirror-inverted to the resistors R 2 ″-R 24 ″ with even reference numbers. The resistor R 25 ″, on the other hand, is preferably chosen different again from these twelve current characteristics.
[0059] The grounding 24 can, as described in the example of FIG. 2 , be arranged at any point of the system. Thus, the contact point P can be connected directly to ground. Therefore, contact points can also be defined in the elevator system that, each by itself, in interaction with the monitoring device, can detect defective points in the suspension-and-traction means.
[0060] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
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A monitoring device for a suspension-and-traction apparatus of an elevator system that includes at least one electrically conductive cord contains a measurement apparatus for determining a resulting resistance. The measurement apparatus is connected to the cord with contacting elements contacting opposite ends of cord. Damage to the suspension-and-traction apparatus is detected by a contact point that can register protruding conductive parts of the cord and, in another embodiment, the contacting elements each contain a plurality of mutually differing resistance elements such that each of at least two electrically conductive cords of the suspension-and-traction apparatus is connected to the monitoring device through two of the resistance elements.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present patent application refers to a process used to automatically iron the edges of slash pockets, and also the machine used to implement said process.
2. Description of Related Art
The ironing operation is currently carried out by hand, and therefore the ironing process and machine of the invention are an absolute novelty.
SUMMARY OF THE INVENTION
The machine of the invention provides for a loading station for the items to be ironed and means to transfer them automatically to the ironing station, where two ironing buffers operate and are situated over and under the ironing plane.
The plane is characterised by the presence of a large window over which the item to be ironed is moved and held, partly supported by the lower ironing buffer and partly supported by threads with suitable orientation adapted to favour the perfect ironing of the fabric and avoid the creation of undesired folds.
For major clarity the description of the invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, whereby:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of a pair of pants with a slash pocket with two edges, one over and one under the pocket cut;
FIG. 2 is a transversal cross-section of the slash pocket with edges in reversed position inside the pocket cut and ready to be ironed;
FIG. 3 is a perspective diagrammatic view of the ironing station of the machine of the invention;
FIGS. 4 to 7 are cross-sections with a transversal vertical plane of the two ironing buffers, each of them showing the position of the said buffers in the different steps of the ironing process.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For a better understanding of the invention, it is necessary to define the different parts of a slash pocket, as the one shown in Figure, 1 , which shows the pocket cut (TT), the edges (F) of the pocket cut (TT), the upper part (PS) and the lower part (P 1 ) of the pocket cut (TT).
FIG. 2 shows the loading station (SC) upstream of the ironing station (SS) shown in FIG. 3 .
At the loading station (SC) the item with the pocket to be ironed is placed as illustrated in FIG. 2 , which diagrammatically shows both a portion of the worktop (P) and a portion of the pocket mouth sectioned with a vertical plane orthogonal to the pocket cut (TT).
The pocket cut (TT) is bordered and finished by a pair of parallel edges (F) with reinforcements (R), while a facing (M) is designed to internally cover the mouth of the pocket.
As shown in FIG. 2 , the item is placed over the worktop (P) with the fabric (T) with the pocket having its external side (LE) up.
Two seams (C 1 , C 2 ) run parallel and equidistant on the fabric (T) with respect to the pocket cut (TT); the seam (C 2 ) is situated on the upper part (PS) of the pocket cut (TT) and affects the facing (M), the edge (F) and the reinforcement (R), while the seam (C 1 ) is situated on the lower part (PI) of the pocket cut (TT) and affects the edge (F) and relevant reinforcement (R), as shown in FIG. 2 .
In FIG. 2 , (T 2 ) identifies the folded sections of the reinforcement (R) and edge (F) that go over the seams (C 1 and C 2 ) and extend towards the pocket cut (TT).
In view of the above, this description continues with a detailed illustration of the machine used to implement the ironing process of the invention.
The machine is provided with a worktop (P) with a slot ( 1 ) that extends from the loading station (SC) to the ironing station (SS), ending in a rectangular window ( 2 ) where the fabric (T) is transferred and held long enough to allow the ironing means (MS) to perform their function correctly.
As shown in FIG. 3 , two pairs of threads ( 3 and 4 ) run on the worktop (P); the threads ( 3 ) of the first pair run inside the slot ( 1 ) and the window ( 2 ) in parallel position close to the border of the slot ( 1 ), while the threads ( 4 ) of the second pair are only extended in the window ( 2 ).
More precisely, the threads ( 4 ) of the second pair are respectively fixed to the connection vertexes ( 1 a ) between the slot ( 1 ) and the window ( 2 ) and continue with diverging direction through the window ( 2 ), as shown in FIG. 3 .
The fabric (T) is transferred from the loading station (SC) to the ironing station (SS) by means of transport blades of known type, which drag the fabric (T) over the worktop (P) along a direction that coincides with the longitudinal axis (X—X) of the slot ( 1 ), which is the same as the axis of the pocket cut (TT).
After the pocket has been placed in the loading station (SC), the first pair of threads ( 3 ) is situated under the fabric (T), and more precisely inside the fold (B) on the fabric (T) near the seams (C 1 and C 2 ), as shown in FIG. 2 .
The position of the threads ( 3 ) guarantees that the position of the edges (F) with relevant reinforcements (R) and the position of the facing (M) are perfectly maintained while the item is transferred from the loading station (SC) to the ironing station (SS), that is to say that the folding lines (B) maintain the distance and the parallel position with respect to the axis X—X of the slot ( 1 ).
The second pair of threads ( 4 ), that is to say the threads situated in the window ( 2 ), guarantee the perfect ironing of the pocket, since the threads ( 4 ) support the fabric (T) inside the window ( 2 ).
The ironing means (MS) include an overlapped pair of buffers ( 5 and 6 ) situated respectively over and under the worktop (P) in the window ( 2 ), both of them being supported by a jack ( 5 a and 6 a ) that allows them to move vertically.
The vertical travels of the lower buffer ( 6 ) are smaller than the travels of the upper buffer ( 5 ), it being understood that the two buffers mutually adhere on a plane coplanar to the worktop (P).
The lower buffer ( 6 ) in idle position is slightly lower with respect to the pair of threads ( 3 and 4 ) so as not to interfere with the correct position of the pieces of fabric (F, R, M) in the ironing station (SS), and particularly inside the window ( 2 ).
The lower buffer ( 6 ) is padded with silicone or honeycomb soft material of known type.
The upper buffer ( 5 ) includes a central body ( 5 b ) having basically the same dimensions as the lower buffer ( 6 ), and, as shown in FIGS. 4 to 7 , laterally provided with an opposite pair of jacks ( 5 c ) with horizontal axis, which support and actuate a pair of divaricating plates ( 7 ) folded with L-shape so as to partially cover the lower face ( 5 d ) of the central body ( 5 b ) with their horizontal wings ( 7 a ).
In the preferred embodiment of the invention, the horizontal wings ( 7 a ) have arched convex longitudinal borders ( 7 b ), so that the adherence points to the fabric (T) are closer to the pocket cut (TT) in the centre and farther from the pocket cut (TT) at the ends.
The presence of the arched shape is due to the need to adjust the ironing tension of the pieces of fabric (F, R, M, T), which must be higher in the central section of the pocket cut (TT), where the fabric can give way more easily, and lower in the ending sections of the pocket cut (TT), where ironing encounters some resistance in the continuity of the fabric (T) and in the seams at the two ends of the pocket cut (TT).
When the upper buffer descends over the lower buffer, the divaricating plates ( 7 ) press the pieces of fabric (T, F, R, M) situated between the two buffers ( 5 and 6 ) and then open out following to the activation of the jacks ( 5 c ).
Once the plates ( 7 ) have divaricated, the upper buffer ( 5 ) irons the pieces of fabric (T, F, R, M) with steam jets coming out of a series of holes drilled on the lower side ( 5 d ) of the central body ( 5 b ), which, according to a known construction, includes channels with valves to distribute and dispense steam through the said holes.
Once the dispensing of steam has ceased, the lower buffer ( 6 ) aspirates the steam dispensed by the upper buffer ( 5 ) by means of a series of upper holes.
Also the lower buffer ( 6 ) has a conventional construction, with a perforated surface and internal channels used to aspirate the steam dispensed by the upper buffer.
The ironing process includes nine operational steps, which are now illustrated in detail with reference to FIGS. 4 to 7 , which, for easier graphical reference, show the position of the ironing means (MS) at each operational step and not the pieces of fabric (T, R, F, M) to be ironed.
The worktop (P) is not sectioned in FIGS. 4 to 7 , which is only shown with a line (P 1 ).
During the nine operational steps the buffers ( 5 and 6 ), the divaricating plates ( 7 ) and the threads ( 3 and 4 ) cooperate to iron the fabric (T), edges (F), reinformcements (R), and facing (M).
The process includes the following sequences of operational steps:
a) raising of the lower buffer ( 6 ) until it slightly presses the threads ( 3 ) that partially sink in the soft surface of the buffer ( 6 ) (see FIG. 5 ); b) descending of the upper buffer ( 5 ) with the divaricating plates ( 7 ) in retracted position, until it adheres on the lower buffer ( 6 ) (see FIG. 6 ); c) divarication of the plates ( 7 ) (see FIG. 7 ); d) downward pressing of the upper buffer ( 5 ) and steam dispensing through the series of holes located on the lower face ( 5 d ) of the central body ( 5 b ) of the upper buffer ( 5 ); e) interruption of steam dispensing; f) steam and air aspiration by the lower buffer ( 6 ) through the said series of holes situated on the upper face; g) interruption of steam and air aspiration; h) raising of the upper buffer ( 5 ) to the idle position at the end of the upward travel and retraction of the divaricating plates ( 7 ); i) descending of the lower buffer ( 6 ) until it has reached the idle position (see FIG. 4 ).
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The present invention refers to a process and machine used to automatically iron the edges of slash pockets, comprising an ironing station with a pair of ironing buffers one over the other and two pairs of threads used to support and keep the section of fabric folded correctly, it being held near a large window crossed by the threads and housing the two buffers, with one buffer over and one buffer under the ironing plane.
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FIELD OF THE INVENTION
[0001] The present invention relates to compositions useful for the suppression of fugitive dust emissions and methods of suppressing dust emissions by application of an aqueous solution comprising a surfactant, wetting agent and an acrylic copolymer. The compositions of the invention are effective in wetting, penetrating and improving particle cohesion and reducing water evaporation. They can also be used as a knockdown agent for airborne dust and for minimising soil and dust erosion, blowing and loss from roads and bulk solids, controlling coal dust, mineral flotation processes, waste management applications and as a binding agent.
BACKGROUND OF THE INVENTION
[0002] Dust dissemination poses safety, health and environmental problems in many environments. Dust particles, both inhalant (up to 30μ) and respirable (up to 10μ), are known to contaminate food and water, and when inhaled, can result in serious respiratory ailments. In other cases, the presence of coal dust may lead to possible spontaneous combustion. Similar concerns are raised in other mining, chemical, steel and waste industries which generate smoke, dust, ash and other particulate matters. Dust emission is also a problem during road construction and the transportation of coal or pulverised minerals in railway cars or trucks.
[0003] The usual method for allaying dust is to apply a water spray either with a fixed or mobile pressurised spray system, gravity fed distribution or by water cannon. Water trucks are commonly used, for example, on mine haulage roads, quarry access, road constructions, unsealed roads and other types of dusty areas supporting traffic. The main problem with using water sprays is that the dust is controlled only for a short period of time depending on climatic conditions. This is particularly the case during road construction where application of the water spray has to be constantly repeated with a frequency of up to every hour or less to provide effective dust control. Even then, the dust abatement performance is often poor and there is a need for ready access to water, which can be particularly difficult to obtain during droughts.
[0004] Various methods have been employed to date in knock down dust suppressants and dust dissemination. Incorporation of hygroscopic salts such as calcium or magnesium chloride in the water sprays is often done in an attempt to retain moisture on the dusty surface, but the method is often disadvantageous due to high salt usage rates, moisture scavenging properties and equipment corrosion. Oil and oil-based emulsions, pine resin tall oil, and lignosulfonate as a by-product of paper-mills have been used for dust control purposes. See for example U.S. Pat. No. 4,417,992 which discloses the use of oil-containing emulsions comprising light paraffin solvents, water and cross-linked polymers for dust control. U.S. Pat. No. 4,746,543 discloses the use of an aqueous solution containing a mixture of water soluble acrylic polymers with water soluble non-ionic glycol polymers with sulfonate nonionic surfactants and co-surfactants as dust control agents. U.S. Pat. No. 4,594,268 discloses the use of an aqueous emulsion of methacrylate polymer as a dust control agent. U.S. Pat. No. 5,194,174 describes the use of non-viscous water based solutions including a polyvinyl alcohol and boric acid for suppressing dust. U.S. Pat. No. 4,801,635 describes a combination of water-soluble anionic acrylic polymers in combination with water-soluble non-ionic glycol polymers in an aqueous medium together with sulfonate surfactants for the control of dust emissions into the environment. U.S. Pat. No. 5,256,444 describes the control of fugitive dust emissions by the application of a water-soluble cationic polymer solution with a foaming agent. European Patent No. 0 134 106 describes compositions for dry dusty soil surface treatment and stabilisation of surface soil by application of an aqueous emulsion of homopolymers and copolymers of acrylic acid and a polybasic salt including surfactants and wetting agents.
[0005] Notwithstanding that there is a wide variety of dust suppressant compositions and methods available, there is a need for new, improved or at least alternative dust suppressant compositions for use in knocking down airborne dust and controlling fugitive dust emissions in the road building, waste control, mining, haulage and related industries. For example, road construction companies often revert back to the use of simple but generally ineffective water sprays rather than using aqueous suppressant compositions with durable dust control effect.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention relates to new and improved or at least alternative methods and compositions suitable for controlling fugitive dust emissions from bulk, granular or powdered solids.
[0007] According to an aspect of the invention there is provided a concentrate for dust suppression which comprises:
[0008] (a) an anionic surfactant;
[0009] (b) a fatty acid alkyl ester; and
[0010] (c) an acrylic-based copolymer emulsion.
[0011] According to another aspect of the present invention there is provided a method of suppressing dust comprising contacting a solid particulate dust producing material with a dust inhibiting amount of a treatment composition comprising a water-diluted concentrate of the invention.
[0012] According to another aspect of the invention there is provided a treatment composition for dust suppression comprising a concentrate according to the invention diluted with water.
[0013] According to another aspect the compositions of the invention can be used as a knockdown agent for airborne dust and for minimising soil and dust erosion, blowing and loss from roads and bulk solids, controlling coal dust, mineral flotation processes, waste management applications and as a binding agent.
[0014] According to yet another aspect of the invention there is provided the use of a fatty acid alkyl ester for improving fugitive dust suppression or knockdown properties of an acrylic copolymer emulsion.
[0015] These and other aspects of the invention are evident from the description and claims which follow.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In accordance with the invention the dust suppression concentrate is suitable for controlling dust on roads, underground roadways, open-cut mines, on mineral entailing piles, controlling dust and wind erosion from surfaces of pulverised coal and mineral piles contained within open transit carts and on other surfaces having finely divided particles subject to dusting.
[0017] The treatment composition of the invention is efficient in creating soil particle cohesion and abating airborne dust. The composition is further useful in wetting, penetrating and improving soil particle agglomeration and reducing water evaporation from soil and particles so treated. These properties assist to suppress dust at locations such as underground mine operations, haul roads, aboveground transfer interchange areas, quarries, road construction operations, stock piles, tips and rubbish dumps.
[0018] The dust suppressant compositions of the invention surprisingly show good synergy between the anionic surfactant, fatty acid alkyl ester and acrylic-based copolymer emulsions. The effectiveness of the compositions exceeds the wetting, penetration, durability and control of known suppression agents.
[0019] The anionic surfactants for use in the present invention are typical of long chain molecules having a long hydrophobic “tail” and a negatively charged “head”. These surfactants are widely used because of their good lathering, detergent and surface active properties. In a preferred embodiment, the sulphonated surfactant is preferably an aliphatic mono- or poly-sulphonated fatty acid, having a surface tension value below 30 dynes/cm.
[0020] Aliphatic mono- or poly-sulphonated fatty acids are preferred, such as those containing 8 to 20 and more preferably 8 to 16-carbon atoms in the fatty acid aliphatic chains. Examples of alkyl groups which may be used in the sulphonated fatty acids include, octyl, nonyl, decyl, dodecyl (lauryl), eicosyl, nicosyl, docosyl, tricosyl and tetracosyl group. The alkanoyl groups which may be used are monounsaturated analogues of those above, that is, octenyl, nonenyl and the like.
[0021] Alkanolamine and alkanolamide sulphonated fatty acids are preferred such as those containing C 1 to C 10 alkyl groups. These compounds are the condensation products of aliphatic fatty acids and hydroxy alkyl amines. Reference to alkanolamine and alkanolamide sulphonate fatty acids includes the mono-, di- and tri-alkanolamine and alkanolamide condensates. Fatty acid diethanolamide and diethanolamines are versatile and widely used surfactants. Examples of the fatty acid component of such compounds include ricinoleic, lauric, linoleic, tall oil, coco, oleic, stearic, capric and isosteric acid, all of which are described in Kirk-Othmer Encyclopedia of Chemical Technology 3rd Edition, Volume 22, at Table 24, which reference is incorporated herein in its entirety. The most preferred sulphonated fatty acids according to this invention are the
[0022] commercially available ethanolamine lauryl sulphates, particularly diethanolamine lauryl sulphate.
[0023] The fatty acid ethanolamine lauryl sulphates, as well the other sulphonated fatty acid surfactants, are useful for their surfactant and detergent properties. However not all sulphate surfactants proved highly efficient in the compositions of the present invention. Other surfactants such as ethoxylated dodecyl benzene sulphonates and dioctyl sulpho succinic acid surfactants whilst being useful in reducing surface tension and improving wetting and penetration into soil particles were found not to be particularly compatible with the polyvinyl acrylic emulsion copolymer due to coagulation.
[0024] The fatty acid alkyl ester is used to provide a low surface tension for the treatment compositions of the invention. Preferred esters of the invention are lactate and soyate esters derivable from corn and soy beans. Reference can be made to a natural ethyl lactate/methyl soyate blend sold under the trade name of Vertec Gold by Vertec Biosolvents. The fatty acid alkyl ester mixture is produced from a blend of ethyl lactate, derived from corn, and methyl soyate, derived from soy bean oil. The ester blend has a low viscosity (5 cp), low surface tension (21.1 dynes & 0.1% sln) and is used as a solvent in degreasing applications and graffiti removal. It is also formulated to be blended with other products such as hand cleaners, ink removers and paint strippers. The ester blend lowers surface tension of the treatment composition to improve wetting and penetration, reduces evaporation (being oil-based), reduces viscosity to improve pouring and mixing, reduces excessive foaming of the surfactant and is believed to form fibrillations with the acrylic copolymer to improve soil particle adhesion at lower application concentrations. Furthermore, this alkyl ester is endorsed by USB (United Soybean Board) as a bio-energy natural derivative for cleaning and gluing functions due to it being derived from natural sources.
[0025] Whilst the nature ethyl lactate/methyl soyate blend is particularly preferred, it will be understood that other such natural or synthetic fatty acid alkyl esters and blends thereof may be used in the treatment compositions and methods of the present invention. The fatty acid esters are typically methyl esters of C 8 -C 18 fatty acids commonly used as lubricants for metal cutting fluids, high temperature grinding and enamel graffiti removal. The lactate esters are commonly used as a solvent for nitrocellulose, cellulose acetate, resins, lacquers, paints and varnishes. The compounds have low surface tensions preferably below 30 dynes/cm, more preferably around 23 dynes/cm.
[0026] Use of acrylic-based copolymers for soil stabilisation, dust suppression and revegetation projects is known. Typically the acrylic polymer is compounded as a waterborne copolymer emulsion and diluted with water to a predetermined solids content before use. The emulsion copolymers can be used to coat soil and sand, binding particles together with a clear flexible film or crust when used in sufficient concentration. This barrier helps prevent erosion of soil and fugitive dust emissions by movement such as caused by wind or water. The acrylic copolymer also tends to reduce moisture evaporation on the soil surface. Once dry, this compound creates a hydrophobic barrier to lock the moisture both present and co-applied in the ground, thus reducing the frequency, volume and need for further applications.
[0027] The acrylic-based copolymers employed in the invention include those of acrylic acid and one or more unsaturated aliphatic carboxylic acids such as 2-chloroacrylic acid, 2-bromoacrylic acid, maleic acid, fumaric acid, itaconic acid, methacrylic acid, mesaconic acid or the like or unsaturated compounds copolymerisable with acrylic acid, for example, acrylonitrile, methyl acrylate, methyl methacrylate, vinyl acetate, vinyl propionate, methyl itaconate, styrene, 2-hydroxy ethyl methacrylate and the like. Suitable polyvinyl acrylic copolymers for use in the treatment compositions of the invention may be obtained from various sources including that sold as MARLOC supplied by Reclamare Company, Seattle, USA. This polyvinyl acrylic copolymer is of irreversible elastomeric character when polymerised in the presence of light, heat or catalyst.
[0028] Another highly preferred acrylic copolymer is ACROCRYL, a styrene acrylic copolymer emulsion, supplied by Nuplex Industries Australia. It has be observed that compositions of the invention made with ACROCRYL shows higher temperature stability especially around 40-50° C. assisting in storage of the concentrate and application once diluted.
[0029] The treatment composition of the invention has been designed to provide for application of acrylic copolymer adhesive agents in lower concentrations. The compositions of the invention are hitherto unknown and the advantages obtained are surprising compared to the polymer emulsions previously known for dust suppression. The compositions once applied penetrate the surface, blocking evaporation and conserving moisture.
[0030] Further agents to improve the stability, workability and surfactant properties of the formulations of the invention can be incorporated into the concentrate. For example, viscosifying agents such as hydrophilic polysaccharides may be incorporated to assist product stability at low concentration and partake in the efficiency of soil or dust particle cohesion. Hydrophilic polysaccharides are well known in the art and particular mention can be made of Xanthan gums such as Keizan manufactured by CP Kelco.
[0031] Xanthan gums further provide useful properties such as thickening, yeast stabilisation, suspension-ability, flow control, foam stabilisation, coating and film formation and textual quality and modification. The hydrophilic polysaccharides may be used in any form, for example, as isolated from a fermentation broth, or as a reconstituted dry product.
[0032] Additional soil wetting agents may be incorporated into the treatment compositions and concentrates of the invention. Representative soil wetting agents include nonionic surface active agents such as ethoxylated alkyl phenols and polyethylene oxide monolaurates.
[0033] Humectants such as magnesium chloride or calcium chloride may be formulated into the concentrates and treatment compositions. These chloride salts work well in helping to retain moisture in the treatment composition once applied to the soil or dust particle substrates. Further additives including preservatives, buffers and pH adjustment agents, colorants, formulating agents and the like may be used in the concentrates of the invention as appropriate.
[0034] The treatment composition is preferably supplied as a concentrate which is diluted prior to application. The concentrate readily dissolves in water and may be diluted either by controlled addition to a stream of water or added in bulk, such as to a tank of water for application. The treatment concentration can range from about 0.01 to 20%, but -preferably has a low concentration such as from 0.05% to 1.0%, more preferably from about 0.1% solution (1 g/L water) to 1.0% solution (10 g/L water). Water used to dilute the concentrate of this invention can be ordinary tap water, grey water, brackish (salty) water (such as from mines) or hard water (up to 30 grains CaCO 3 ). The treatment composition shows unrivalled efficiency and synergy when compared side-by-side with the individual ingredients, and particularly at the preferred low concentration of about 0.1% solution.
[0035] The concentrate and diluted solutions are nonflammable and susceptible to decomposition by soil micro-organisms. Yet the treatment compositions and methods provide effective residual or long term dust control compared to water or simple suppression formulations from a few hours or a day (at concentrations below 0.1%) to up to 7 days or more (at concentrations above 0.1%)
[0036] In controlled field trials, the compositions of the invention were found to provide 3 to 4 times more moisture conservation when used on dusty roads than water alone. The results suggest that when compared to the use of water at the same application rate and exposure time and conditions, the compositions of the invention were efficient in reducing respirable dust volume by 77% and inhalant dust volume by 78% at 0.2% concentration.
[0037] The compositions of the invention are also suitable for mineral flotation processes, separation and mineral washes due to the detergent effect of the surfactant compositions.
[0038] The compositions may also be used as a binding agent for seed germination control where seeds are anchored to their sowing location until germination takes place.
[0039] It will be understood that different concentrations, application rates and protocols, preferred water types, flow rates and nozzle applicator sizes and additives and diluents may be monitored depending on the dust suppression required, substrate or soil type encountered and the like as would be well known or ascertainable by one skilled in the art.
[0040] The present invention will now be described with respect to non-limiting examples which are regarded solely as illustrative and not unnecessarily restricting on the scope of the invention.
EXAMPLES
1. Concentrates
[0041] The dust suppression concentrate of the invention is prepared by required mixing order to avoid lumps and coagulation and ageing stability. The fatty acid alkyl esters (Vertec Gold) are emulsified with the anionic surfactant (Gardinol DA) for at least 30 minutes. The viscofying agent (Xanthan polysaccharide gum) is then added to the vortex to be dispersed in the emulsified esters and surfactant for at least 30 minutes. Once the Xanthan gum wets and expands, water is added to thin out the dispersion. The acrylic-based copolymer (MARLOC or ACROCRYL) is added as final step to provide a concentrate of about 40-55% solids and having a surface tension of about 27-29 dynes/cm. The final homogenisation is performed for minimum an hour. Representative concentrates are depicted in Table 1 below:
[0000]
TABLE 1
Exemplified Formulations and Range (% weight)
Ingredient
Trade Name
Ex. 1
Ex. 2
Ex. 3
Ex. 4
Ex. 5
Ex. 6
Range
1.
DEA Alkyl Sulphate
Gardinol DA
10
10
12
12
12
12
2-20
2.
Methyl Soyate/
Vertec Gold
10
6
10
6.2
6.25
6.35
5-20
Ethyl Lactate Blend
3.
Xanthan gum
Kelzan
2
—
3
0.1
0.05
0.05
0-3.0
4.
Water
Tap
—
—
—
2
5
2
0-10
5.
Polyvinyl Acrylic
MARLOC
78
84
75
79.7
76.7
—
30-95
Copolymer
6.
Styrene Acrylate
ACROCRYL
—
—
—
—
—
79.6
30-95
Copolymer
2. Treatment Compositions
[0042] The dust suppressant treatment compositions were prepared by diluting 1/1,000 of the concentrate to water. The efficiency of the treatment composition as a dust suppressant was evaluated by adding a 30 ml aliquot of the 0.1% solution on to 100 g of ground top soil in a 1 L jar with an opening of 70 mm in diameter. Comparative examples were prepared in parallel and compared with each of the individual components at the same 0.1% concentration.
[0043] The jars were charged with ground top soil to which the treatment compositions were added and then exposed untouched under high draft in an 8-cubic meter fumehood at a temperature of 21° C. and 35% relative humidity. After 36 hours of evaporation the jars were tumbled at 60 rpm for 30 minutes.
[0044] The efficiency of the treatment compositions was assessed by observing the disintegration of the cake into loose soil particles. It was found that the soil cakes for various ingredients including polyvinyl acrylic copolymers (MARLOC) were observed to have disintegrated into loose powder under the tumbling action. The loose powder has the reversed consistency of ground topsoil that becomes airborne under turbulence. In comparison, the treatment compositions of the invention were found to hold the cakes intact after 30 minutes of tumbling at 60 rpm. The results for the tumble test are depicted in Table 2 below.
[0000]
TABLE 2
Comparative Tumble Test Results after 36 hours evaporation
Solids of
pH
Surface
Evaporation
Concen-
0.1% @
Tension
Tumble Test
Product
Chemical
tration
22° C.
0.1%
0.1%
Water
tap
Nil
7.1
59.5
3/3 fail
Marloc
Polyvinyl
60%
6.6
35.0
3/3 fail
Acrylic
Duskil
Pine Resin
35%
6.9
27.3
3/3 fail
Emulsion
MgCl 2
Inorganic
100%
7.2
42.4
3/3 fail
Salt
3M Dust
Ex. 4 &
40-55%
6.5
27.1
3/3 PASS
Suppres-
Ex. 5
sant
[0045] The concentrates and treatment compositions of the invention are found to be efficient in dust suppression across a wide range of situations and conditions. The treatment composition is found to be effective in wetting, penetrating and improving soil and dust particle cohesion and reduces water evaporation. The achieved properties assist to suppress dust at locations such as underground mine operations, haul roads, aboveground transfer interchange areas, quarries, road construction operations and stock-piles. The treatment compositions show strong synergism with the three main components being the anionic surfactant, fatty acid alkyl esters and polyvinyl acrylic emulsion copolymer.
[0046] The concentrate of Ex. 6 containing the styrene acrylate copolymer ACROCRYL was diluted with tap water at various low concentrations. Surface tension values of below 30 dynes/cm provide for good wetting of substrates. The surface tension of the resultant treatment composition was below 30 dynes/cm at all lower concentrations ranging from 0.012 to 0.10 compared to tap water (reference) at about 52 dynes/cm. Higher concentrations of composition to water likewise have surface tensions well below 30 dynes/cm, more preferably below 26 dynes/cm. That is, even at high dilution (and hence low concentration), the product concentrates still gave treatment compositions having surface tensions below 30 dynes/cm post dilution. The treatment compositions thereby exhibiting excellent wetting ability. The results are shown in Table 3 below.
[0000]
TABLE 3
Surface tension studies of low concentration treatment compositions
from the Example 6 concentrate in tap water (dynes/cm)
% Concentration
Example 6
Surface Tension
—
52.0 (water)
0.012
29.7
0.025
27.7
0.050
27.6
0.075
27.3
0.10
26.2
3. Field Trials
[0047] The Nepean Gorge Lookout road in the Blue Mountains National Park, New South Wales, Australia has a gravel road being a mixture of blue metal and powdery dust covering clayed compacted soil. Driving vehicles on the road is a major source of inhalant and respirable dust emissions.
[0048] A 7,000 litre water truck equipped with drip bar, shower heads and water cannon driven by a motorised pump was supplied by Penrith City Council. Tests were conducted with water and the Ex. 6 composition of the invention diluted with water to 2:1,000 (0.2%) at an application rate of about 8-10 L/m 2 and truck speed of 10 km/h over 6 passes with 10 minute gaps. On day 2 and 3, the application volume was reduced to half and quarter respecitvely. Three days following the last application, the truck was driven along the road at 40-50 km/h for 10 passes to generate the dust for collection.
[0049] Dust suppressant treatment compositions were prepared in situ by diluting 14 L of the concentrate directly into the 7,000 water tank. Dissolution was competed by self-mixing following normal agitation following driving the truck for about 200 m. At slow speeds, sudden brake motions further assisted mixing.
[0050] Samples from the tank showed good mixing with the composition having a pH of about 7.1 and surface tension of about 28.5 dynes/cm.
[0051] Dry soil was taken from tyre tracks of non-treated areas a day before application. The surface was dug with a crowbar to about 2.5 cm depth and the soil collected in plastic vials and sealed for moisture analysis. Further samples were taken following application of either water or diluted concentrate as above at 24, 48 and 72 hours and 10 days in a similar manner. The weather conditions were sunny to partly cloudy and overcast, light to moderate winds and maximum temperatures ranging from about 25-32° C.
[0052] Dust volume recording was conducted by Coal Services Health Environmental Monitoring according to Australian Standards for gravimetric weight gain observation. DuPonnt air sampling pumps were employed to aspire dust particles into Cassella Cyclone monitors (respirable dust) and IOM 25 mm open-face samplers (inhalant dust).
[0053] An analysis of moisture retention of the treated and untreated soil was made at 24, 48 and 72 hours and after 10 days using a forced air oven at 100 C under standard conditions. The results are set out in Table 4 below:
[0000]
TABLE 4
Moisture Retention Analysis (% average moisture)
Test Product
24 h
48 h
72 h
10 days
Water
2.14
2.22
2.51
2.34
Ex. 6 (0.2%) in water
6.06
6.41
10.7
3.71
[0054] The compositions of the invention were found to be highly effective at retaining moisture compared to water alone. After 24 hours a 2.8 times improvement was observed, after 48 hours a 2.9 times improvement and after 72 hours a remarkable 4.3 times improvement. Even after 10 days an improvement of about 1.6 times that of water alone was observed.
[0055] These results translated into remarkable dust suppression results for the compositions of the invention. Table 5 below shows the results of dust generation studies for the soil at 3 days (72 hours) post treatment.
[0000]
TABLE 5
Dust Generation Studies at 72 Hours (mg/m 3 )
Test Product
Inhalant
Respirable
Water
8.9
1.9
Ex. 6 (0.2%) in water
5.1
1.1
[0056] The compositions of the invention were found to be highly effective at suppressing both inhalant and respirable dust at about 1.7 times as compared to water alone.
[0057] Following an initial heavy application, periodic application of the compositions of the invention (about once or twice a day to every two days) would save water, labour and equipment cost over conventional road and surface wetting procedures. A typical application protocol is:
WEEK 1: Day 1: Apply 0.2% composition at 8-10 L/m 2 with up to 6-8 passes and a gap of 10 minutes
Days 2-7: 2 continuous passes per day
WEEK 2: 2 continuous passes twice a week WEEK 3 (onwards): 2 continuous passes once a week or as needed
[0062] The compositions greatly assist in moisture retention and conservation and particle agglomeration. On average, the compositions of the invention have about 3 times more moisture retention activity than water alone and at least 50% more dust abatement ability than water alone. Use of polyvinyl acrylic copolymer emulsions in the compositions of the invention such as from test Examples 4 and 5 gave similar dust suppression and abatement results.
[0063] The compositions of the invention also show improved handling and activity over similar known dust suppression agents. The compositions are easy to handle, readily miscible with water from various sources and do not need prior dilution.
[0064] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification individually or collectively, and any and all combinations of any two or more of said steps or features.
[0065] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that the prior art forms part of the common general knowledge in the field of endeavour.
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The present invention relates to compositions useful for the suppression of fugitive dust emissions and methods of suppressing dust emissions by application of an aqueous solution comprising a surfactant, wetting agent and an acrylic copolymer. The compositions of the invention are effective in wetting, penetrating and improving particle cohesion and reducing water evaporation. They can also be used as a knockdown agent for airborne dust and for minimising soil and dust erosion, blowing and loss from roads and bulk solids, mineral flotation processes, waste management applications and as a binding agent.
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This is a continuation of copending U.S. application Ser. No. 07/580,222, now U.S. Pat. No. 5,189,820, filed on Sep. 10, 1990.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a frame in which a plurality of frame elements are angularly connected to each other through at least one connecting element to form an enclosure, to accommodate therein an article such as a picture, a photograph, a glass plate, a rear plate, an illumination louver, a smoothly planed board for a building interior trim, or the like.
2. Description of the Prior Art
A frame is disclosed in Japanese Patent Publication No. 26439/1964 in which a plurality of frame elements are connected respectively through a plurality of connecting elements to form an enclosure.
That is, the above Japanese Patent Publication No. 26439/1969 discloses the connecting elements which are formed respectively with connection engaging pawls which engage respectively with the frame elements. Each of the connection engaging pawls is formed on a surface of an L-shaped element in the form of a thin plate.
The connection element utilizes the connection engaging pawl to engage with the frame element. In the case where the article to be accommodated is mounted to or demounted from the interior of the frame in order to form the latter, the connection engaging pawl of the connecting element must be operated each time to demount the frame element from the frame.
Japanese Utility Model Publication No. 27318/1973 discloses other types of connecting elements.
Disclosed in the above Japanese Utility Model Publication No. 27318/1973 is a the connecting element in which a plain or flat plate is folded perpendicularly to form a connecting arm, and the connecting arm is formed with an inclined surface.
A dovetail groove in the frame element is inserted into the connecting arm, and an inclined surface of the connecting arm is tightened by screws from the side portion of the dovetail groove, so that the frame element is connected to the connecting element.
The connecting arm is inserted through the end of the dovetail groove of the frame, and an engaging pawl or a screw serves as a wedge and is engaged with the connecting arm, so that the frame element is connected to the connecting element.
Since the frame element is connected to and fixed to the connecting arm of the connecting element so that the frame is formed, the article accommodated in the frame can be taken out or removed such that the frame element is moved to its open position from the opposed connecting arms of the respective left- and right-hand connecting elements, and is separated from the connecting arm of the connecting element.
Alternatively, the article to be accommodated can be removed in the following manner. That is, the frame element is moved to its open position from the opposed connecting arms of the respective left- and right-hand connecting arms. The dovetail groove is utilized to move the frame element from the left- and right-hand connecting arms to enlarge the frame. An engaging section of the frame element is removed from the front-face peripheral edge section of the article to be accommodated.
Subsequently, another article to be accommodated is inserted into a space within the frame between the frame elements thereof. The connecting arm of the connecting element is pushed into the frame element. The frame element is agains connected and engaged by the connecting arm. Thus, the frame is formed.
Furthermore, a plurality of frame elements cooperating with each other to form a frame are disclosed in Japanese Utility Model Publication No. 24390/1975.
Disclosed in the above Japanese Utility Model Publication No. 24390/1975 is such an arrangement that, in order to mount and demount the article to be accommodated to and from each of the frame elements which cooperate with each other to form the frame, the frame element is composed of a pair of upper and lower frame elements. The upper frame element is assembled to the lower frame element so as to be angularly movable thereto partially. The lower and upper frame elements are abutted against each other by a spring. The article to be accommodated is held between the upper and lower frame elements.
Replacement of the article to be accommodated with respect to the frame, which are formed by the frame elements, is practiced in the following manner. That is, the upper frame element is angularly moved upwardly through about 90 degrees to rise, as a fulcrum of a portion at which the lower and upper frame elements are assembled with each other for angular movement. The upper frame elements rise subsequently, to open the upper edges at the four sides of the frame. The article to be accommodated is mounted to and demounted from the open face.
Further, a record-jacket holding panel is disclosed in Japanese Utility Model Provisional Publication No. 161565/1988 in which a lower frame element and an upper frame element are connected to each other through a film hinge, to form a frame.
In the above Japanese Utility Model Provisional Publication No. 161565/1988, a plurality of frame elements are framed such that their respective end faces are abutted against each other, and a rear plate is held along the outer periphery of the rear plate. The frame elements have their respective front-face elements and respective rear-face elements whose respective outer surface portions are connected to each other through a hinge. A spring is provided between the front-face element and the rear-face element. By the spring, the front-face element is biased such that record jackets superimposed upon the rear plate are clamped with respect to the rear plate. The front-face element is movable angularly about a hinge section against the spring. A record-jacket pushing bore is formed through the rear plate.
Mounting and demounting of the article to be accommodated to and from the frame are practiced from the frame front surface, as follows. That is, the front-face elements of the four-side frame elements rise upwardly about 90 degrees, and the upper edge of the frame is open.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a frame which is so simple in construction that, when an article to be accommodated is mounted and demounted, a plurality of frame elements are not removed from at least one connecting element, and that two frame elements having a lower frame element and an upper frame element are not connected to the connecting element. Each of the frame elements, in a simple frame structure, is engaged with the connecting elements for angular movement.
It is another object of the invention to provide a frame in which each of a plurality of frame elements is mounted to at least one connecting element so as to be movable angularly about a longitudinal axis of the frame element, whereby a side plate of the connecting element serves also as a falling-out preventing section with respect to a bearing section for the angularly movable frame element. Thus, when the frame element is moved angularly with respect to its open position, the frame element does not fall down and, for this reason, it is possible to easily move an article to be accommodated into and out of the frame.
It is still another object of the invention to provide a frame which is extremely simple in construction, which involves no waste of material, and which is easy to use in many applications.
A frame according to the invention can be utilized, for example, for building fittings or fixtures, furniture, an exhibition case, a signboard, an illumination appliance, or the like.
In the invention, only fitting between two kinds of elements including a frame element molding-processed by extrusion of aluminum or the like and a connecting corner element molded from elastic resin such as polycarbonate, polyacetal or the like, enables each frame element to be connected to the connecting element for angular movement, to form the frame. The frame element on one side of the frame is angularly moved outwardly to open one side edge of the frame. Thus, taking-in and -out of the article to be accommodated including the rear plate and the like can easily be done through the open location, without breaking the frame.
An intermediate partition is provided within the frame element to divide the space into two space sections. One of the two space sections is brought to a space for holding the front-face peripheral edge portion of the article to be accommodated. The other space section is brought to a space in which the connecting element is fitted.
An inward flange is provided at an outward end of the space in the frame element, in which the connecting element is fitted, so that a concave bearing section is formed.
In one aspect of the invention, the distance from the outward side of an angularly-movable shaft of the connecting element to an angular-movement stoppage section and a distance from a concave bearing section of the frame element to an engaging pawl is made equal to each other or is equalized each other, whereby an opening width of the fitting space in the frame element with respect to the connecting element is narrowed correspondingly to the projecting portion of the flange.
Further, the projecting dimension of the flange is equal to or larger than one half the thickness of the shaft at the forward end of the side plate.
The corner of the side plate of the connecting element is cut out to form a convex shaft at the end of the side plate.
The convex shaft is provided at the forward end of the side plate which serves as a leaf spring.
A convex, concave or any other engaging section for prevention of getting-out may be provided at a location engaged with the intermediate partition of the frame element or the connecting section between the shaft section and the connecting element.
An angular-movement stoppage section is provided at a position where the engaging pawl is abutted against the connecting element, and at a location where the frame element is moved to its closed position, or where the frame element is moved to its fully open position.
Another angular-movement stoppage section is provided on an angular-movement sliding contact face between the connecting element and the frame element. The angular-movement stoppage section is provided midway of angular movement of the frame element, a location where the frame element is open to the maximum, a location where the frame element is closed, or the like.
An angular-movement engaging pawl is provided on the outer periphery concentric with a center of the concave bearing section, that is, on the intermediate partition.
In the case where the article to be accommodated is held between the intermediate partition of the frame element and the front-face engaging section, the intermediate partition is brought to a curved surface concentric with the concave bearing section.
The connecting element is arranged such that, when the frame element is moved to its open position, the rear-face section of the connecting element projects as compared with the position of the rear-face portion of the frame element.
A cut-out maybe provided at the end of the flange. The cut-out has such a dimension that its length is of the order to two times a distance from the center of the convex shaft section to the frame-element surface of the concave shaft section.
At this time, a step is provided above the cut-out of the frame element.
A tongue-like spring, which has, at its forward end, an inclined surface and which can be urged against a part of the connecting element, may be provided at a position where the frame element is moved to its closed position, that is, at the angular-movement stoppage position.
The tongue-like spring provided on the connecting element has a forward end which may be brought to a hook-shaped engaging pawl.
In this case, the tongue-like spring is formed with a finger catch for releasing the hook-shaped engaging pawl.
In the case where an article to be accommodated thinner than a predetermined dimension, the article is clamped with a spring provided on the outer peripheral surface of the intermediate partition of the frame element at a location between the intermediate partition of the frame element and the front-face engaging section.
The front-face engaging section for holding the front-face peripheral edge section of the article to be accommodated is provided at the upper edge of the frame element.
The connecting element may be such that one of the connecting sections is brought to a pivotal connecting section, and the other connecting section is brought to a connecting section which is not pivotal.
At this time, a cap is mounted to an end of a space in the angularly moved frame, in which the article is accommodated.
The sliding contact surface between the connection engaging section of the frame element and the connection engaging section of the connecting element is inclined whereby the connection engaging section of the connecting element is fed axially outwardly of the frame element under the action which moves angularly the frame element outwardly.
In the connecting element, the connection engaging section, the side plate and the angular-movement stoppage section are united together, and a triangular reinforcing plate is formed in unison at the angular-movement stoppage section which is arranged perpendicularly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a part of one of a plurality of frame elements according to a first preferred embodiment of this invention;
FIG. 2 is a perspective view of one of a plurality of connecting elements according to the first embodiment;
FIG. 3 is a cross-sectional view of a part of the first embodiment;
FIG. 4 is a cross-sectional view of a part of a second embodiment;
FIG. 5 is a cross-sectional view of a part of the first embodiment at another position;
FIG. 6 is a cross-sectional view of a part of a third embodiment;
FIG. 7 is a perspective view of a part of the first embodiment as viewed from the bottom;
FIG. 8 is a perspective view of the entire frame in which a part of the first embodiment is cut out and parts thereof are removed;
FIG. 9 is a cross-sectional view of the first embodiment, showing the relationship between the first embodiment and an article to be accommodated;
FIG. 10 is a cross-sectional view of FIG. 9 under another condition;
FIG. 11 is a cross-sectional view of FIG. 9 under still another condition;
FIG. 12 is a fragmentary partially cut-out perspective view of a frame element according to a fourth embodiment;
FIG. 13 is a cross-sectional view of the embodiment illustrated in FIG. 12;
FIG. 14 is a cross-sectional view of FIG. 3 under another condition;
FIG. 15 is a cross-sectional view of a fifth embodiment;
FIG. 16 is a cross-sectional view of FIG. 15 under another condition;
FIG. 17 is an exploded perspective view of a sixth embodiment;
FIG. 18 is an exploded perspective view of a seventh embodiment;
FIG. 19 is a partially cut-out perspective view of the entire embodiment illustrated in FIG. 18;
FIG. 20 is a cross-sectional view of an eighth embodiment;
FIG. 21 is a cross-sectional view of a ninth embodiment;
FIG. 22 is a perspective view of a connecting element according to a tenth embodiment;
FIG. 23 is a partially broken-away perspective view of an eleventh embodiment; and
FIG. 24 is a partially cut-out perspective view of a twelfth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, there is shown a frame which is composed of a plurality of frame elements 1 (only one of which is shown) molding-processed by extrusion of a blank formed of a material such as aluminum or the like, and a plurality of connecting elements 5 (only one shown) molded by elastic resin such as polycarbonate, polyacetal or the like.
Each of the frame elements 1 is formed with an intermediate partition 11 at a side surface of a side plate 20. The intermediate partition 11 is curved convexly downwardly along a longitudinal direction. A front engaging section 12 extending along the longitudinal direction and curved convexly toward intermediate partition 11 is formed at an upper edge of the side plate 20. The intermediate partition 11 has its forward end which is provided with an engaging pawl 13.
The side plate 20 is provided with a support section 14 at a location below the intermediate partition 11. The support section 14 is adapted to support the outer side section of the connecting element 5. A flange 15 projects toward the forward end of the intermediate partition 11 from the lowermost edge 18 of the side plate 20, through a step 19 (FIG. 7). Thus, a space A is defined between the side plate 20 and the intermediate partition 11.
The flange 15 is curved to form a concave bearing section 15a. An antiskid engaging section 16 for receiving a convex by edged shaft section 51a of the connecting section 5 is provided adjacent a location above the concave bearing section 15a. A concavely curved connection engaging section 17 engageable with a correspondingly sized connection engaging section 55 of the connecting element 5 is provided on an inner surface of the convexly curved intermediate partition 11.
FIG. 2 shows the connecting element, by which two frame elements 1 connect at an angle (as best seen in FIG. 7) to form a corner of a frame, 5 which has a pair of intersecting outer side plates 51 each consisting of a leaf spring extending perpendicularly. An inner surface of each side plate 51 at an upper edge thereof is formed with a first extended angular-movement stoppage section 53 at a position where the frame element 1 is moved to its open position. A pair of convexly-curved angular-movement sliding-contact surfaces 54a and 54b are provided for guiding the engaging pawl 13 of the frame element 1, each curved in a concentric relation to the center of the concave bearing 15a (when a frame element 1 is fitted thereto); and formed to extend downwardly away from the first angular-movement stoppage section 53. A second angular-movement stoppage section 54 located midway of angular movement of the frame element 1 is formed, in a concave manner, at a location between the convexly curved angular-movement sliding-contact surfaces 54a and 54b. A third angular-movement stoppage section 52 is formed at a lower end of the angular-movement sliding-contact surface 54b at the time the frame element 1 is moved to its closed position. The connection engaging section 55 engageable with the connection engaging section 17 of the frame element 1 is formed at the upper surface of the side plate 51 and at the upper surfaces of the respective convexly curved surfaces 54a and 54b. Portions of the connection engaging sections intersect at the top of the intersection corner formed by side plates 51, as best seen in FIG. 2. A triangular reinforcing plate 50 is formed in unison with the third angular-movement stoppage section 52. The triangular reinforcing plate 50 has its inner edge which is formed with a support wall 56 for an article 3 to be accommodated (refer to FIG. 9). The triangular reinforcing plate 50 is provided therein with a bore 57 for wall surface fixing. A pivot section 51a is formed at a part of the lower edge of the side plate 51. In order to form the side plate 51 into a leaf spring, a corner portion of the outer side wall of the side plate 51 is cut out to form a cut-out 58. An inclined surface 52a for feeding the engaging pawl 13 of the frame element 1 into the third angular-movement stoppage section 52 is formed at the upper portion of the third angular-movement stoppage section 52. Further, an inclined surface 152a may be formed at a forward end of a tongue-like spring 152 which is provided at the curved surfaces 54a and 54b, to form an angular-movement engaging section.
FIG. 3 shows a condition under which the frame element 1 and the connecting element 5 are fitted in each other. FIG. 3 illustrates a partial cut-out 51p at the forward end of the side plate 51, and an inclined surface 152a at the forward end of the tongue-like spring 152.
FIG. 4 shows an embodiment which comprises an angular-movement fixing engaging pawl 152b provided on the tongue-like spring 152 engageable with the engaging pawl 13 of the frame element 1, and a clamp wall 152h provided on the third angular-movement stoppage section 52.
FIG. 5 shows movement of the engaging pawl 13 of the frame element 1 from the inclined surface 52a to the first angular-movement stoppage section 53. Note that relative angular movement between frame element 1 and the corresponding side of the connecting element is about a direction parallel to the side.
FIG. 6 shows an embodiment in which curvature of the side plate 51 is made large.
The frame elements 1 and the connecting elements 5 are used at the upper edges of the side plates 51 to form a rectangular frame illustrated in FIG. 8.
Regarding the rectangular frame, assembling of the frame elements 1 and the connecting elements 5, mounting of the article 3 to be accommodated, opening of the frame elements 1, and so on will be described in order.
The frame elements 1 are fitted in each other in such a manner that the side plates 51 of the connecting elements 5 illustrated in FIG. 2 are pushed until the third angular-movement stoppage sections 52 are engaged respectively with the engaging pawls 13 of the frame elements 1, from the open sections at the lower ends of the respective spaces A in the frame elements 1 illustrated in FIG. 1. In this manner, the frame elements 1 are connected to each other. As is readily seen, for example in FIGS. 7, 19, 23 and 42, the intersecting sides of connecting element 5 are formed to be shorter than the frame elements engaged therewith.
At this time, the side plate 51 is pushed by the flange 15, and is accommodated in the space A in the frame element 1 while being elastically deformed.
Further, the convex shaft section 51a of the side plate 51 is in sliding contact with the concave shaft section 15a of the frame element 1, and serves as a pivotal section for the frame element 1.
At this time, the connection engaging section 17 of the frame element 1 and the connection engaging section 55 of the connecting element 5 are fitted in each other simultaneously.
When the side plates 51 of the four connecting elements 5 are pushed respectively into the spaces A at both the ends of the four frame elements, assembling of the frame illustrated in FIG. 8 is completed.
Mounting of the article 3 to be accommodated is practiced in the following manner. That is, as shown in FIGS. 9 or 11, the frame element 1 is moved angularly about the convex shaft section 51a of the connecting element 5 and is moved to its open position. The article 3 to be accommodated rests on the curved intermediate partition 11 of the frame element 1. The frame element 1 is again moved angularly about the convex shaft section 51a and is moved to its closed position as shown in FIG. 10.
At this time, the curved intermediate partition 11 of the frame element 1 is into sliding contact with the peripheral edge of the article 3 to be accommodated at the rear face thereof, so that the article 3 to be accommodated is held between the intermediate partition 11 and the engaging section 12 of the frame element 11 at the front face thereof.
If the angle of the angular movement of the frame element 1 is made large and, as shown in FIG. 9, if frame element 1 is brought down such that the forward end of the front-face engaging section 12 is located below the forward end of the intermediate partition 11, the article to be accommodated can be taken into and out from the lateral side of the frame element 1.
Further, if the frame elements 1 at the adjacent two sides are moved to their respective open positions as shown in FIG. 8, it is possible to mount and demount the article 3 to be accommodated to and from the frame elements 1 from the above.
Stoppage of the angular movement of the frame element 1 with respect to the connecting element 5 is practiced by the engaging section 13 of the frame element 1 and the first through third angular-movement stoppage sections 53, 54 and 52 of the connecting element 5.
It is possible to optionally set resistance at stoppage by the spring strength of the side plate 51 and/or the spring strength of the intermediate partition 11 of the frame element 1.
The inclined surface 52a provided in front of the third angular-movement stoppage section 52 shown in FIG. 5 serves to feed the engaging pawl 13 of the frame element 1 into the stoppage section 52.
The engaging section 13 of the frame element 1 is urged against the third stoppage section 52 by the inclined surface 52a, so that it is possible to prevent the frame element 1 from being inadvertently moved to its open position with respect to the connecting element 5.
The angle between the inclined surface 52a and the third stoppage section 52 is made acute, whereby it is possible to fixedly mount the frame element 1 to the connecting element 5 with a strong force.
Furthermore, as shown in FIG. 3, the steep inclined surface 152a is provided in front of a tongue-like spring 152 which is provided at the pair of curved surfaces 54a and 54b of the connecting element 5. The tongue-like spring 152 is urged toward the interior of the connecting element at sliding contact between the curved surfaces 54a and 54b and the engaging section 13. Thus, the engaging section 13 of the frame element 1 is engaged with the steep inclined surface 152a.
The strength of the engagement is adjusted by appropriate choice of the material and configuration of the tongue-like element 152, the angle of the inclined surface 152a, and the like.
The arrangement may be such that the forward end of the tongue-like spring 152 is not brought to the inclined surface 152a, but, as shown in FIG. 4, is brought to an engaging pawl 152d, so that the forward end of the tongue-like spring 152 is brought to an antiskid engaging section in mesh with the engaging section 13.
Moreover, the arrangement may be such that the engaging pawl 152d and the inclined surfaces 52a of the curved surfaces 54a and 54b are used together, the engaging pawl 152d of the tongue-like spring 152 can be broken and cut at a cut-out 152e, the broken and cut frame element 1 is brought to a frame section which is movable angularly, and the frame element 1, in which the engaging pawl 152d of the tongue-like spring 152 is maintained as it is, is brought to an immovable frame section. In this manner, it is possible to optionally form the angularly-movable frame section and the angularly-immovable frame section by the same connecting element 5.
A fixing releasing pawl or a finger catch 152f for the engaging pawl 152d is provided at the lower end of the tongue-like element 152.
The arrangement may be such that another element (not shown) is assembled in substitution for the engaging pawl 152d provided at the tongue-like spring 152 according to the embodiment, to optionally practice switching of engaging and disengagement of the engaging section 13.
In order to enhance close contact between the corner of the frame element 1 and the corner of the tablet, the frame element 1 having its corner cut through 45 degrees is mounted to the connecting element 5. When the frame elements 1 are moved angularly toward the outside from the condition that the cut surfaces of the frame elements 1 are abutted against each other, portions of the frame elements 1 getting inwardly of the convex shaft sections 51a impinge against each other and become immovable. Accordingly, in order to avoid such collision, as shown in FIG. 7, a cut-out 18 must be provided at the ends of the adjacent flange 15.
In the case where the tablet is seen as a commodity, the cut-outs 18 serve as such severe defects that bores are formed respectively at the corners of the tablet.
Close fitting at the corners of the tablet requires a close-fitting accuracy of the corners, as will be called life of the tablet.
Further, if the feeding force of the inclined surface 52a is made large and if the forward end of the convex shaft section 51a is moved outwardly together with opening of the shaft element 1 as shown in FIGS. 5 and 6, the convex bearing section 15a of the frame element 1 is pushed outwardly by the spring action of the side plate 51.
In this manner, the spring force of the side plate 51 moves the concave bearing section 15a of the frame element 1' outwardly, as indicated by the phantom lines in FIGS. 5 and 6, when the frame element 1 is angularly moved outwardly so as to be opened.
When the concave bearing section 15a is moved outwardly under the spring force of the side plate 51, the impinging portion between the end face of the frame element 1 and the end face of the adjacent frame element 1 during angular movement thereof is reduced correspondingly to the outward movement. Accordingly, it will suffice that the cut-out 18 is small.
Moreover, in order to make the cut-out 18 even smaller, as shown in FIG. 6, a thin-wall section 151a may be provided at the forward end of the side plate 51 to reduce the convex shaft section 51a.
Alternatively, if a metallic spring of the order of 0.4 mm to 0.5 mm is assembled as the convex shaft section 51a, it is possible to further reduce the convex shaft section 51a.
Furthermore, if the sliding contact surface between the connection engaging section 17 of the frame element 1 and the connection engaging section 55 of the connecting element 5 is brought to a screw-feeding inclined surface, closing angular movement of the frame element 1 enables the connecting element 5 to be drawn into the space A in the axial direction of the angular movement.
Further, such angular movement as to move the frame element 1 to its open position enables the connecting element 5 to be fed outwardly of the angular movement shaft from the space A.
As a result, it is possible to move the center of the convex shaft section 51a outwardly of the surrounding of the frame elements 1.
Furthermore, as shown in FIG. 7, if the step 19 projecting upwardly of the cut-out 18 is provided so that it is made difficult to view the cut-out 18 from the forward portion of the tablet, the arrangement is further effective.
In the case where the article 3 to be accommodated has a relatively small thickness, there may be concern that a gap will occur between the front-face engaging section 12 of the frame element 1 and the article 3 to be accommodated.
In order to avoid this problem, in the embodiment illustrated in FIGS. 12 through 14, a leaf spring 61a located in to the intermediate partition 11 is mounted to a space between the intermediate partition 11 and the front-face engaging section 12 of the frame element 1. With such an arrangement, the article 3 to be accommodated is pushed from its rear face by the leaf spring 61a, while the frame element 1 is moved to its closed position from the condition that the article 3 to be accommodated rests on the intermediate partition 11, and is urged against the front-face engaging section 12 of the frame element 1. Thus, the above-described gap is prevented from occurring.
Furthermore, in an embodiment illustrated in FIGS. 15 and 16, a leaf spring 61 folded in a thin configuration and having a lower portion curved at n is fixedly mounted to a position between the intermediate partition 11 and the front-face engaging section 12 of the frame element 1. Thus, it is possible to produce similar functional advantages. The configuration and the mounting position of the connecting engaging sections 55 and 17 of the respective frame element 1 and connecting element 5 are determined depending upon the fact that the connecting section for preventing movement of the frame element 1 and the connecting element 5 in the angular-movement axial direction is brought to detachable type or fixing type.
In the case where the connection section is to be of a detachable type, the left- and right-hand frame elements 1 adjacent the frame element 1 to be demounted are moved angularly to a predetermined angle and are moved to their open positions. The groove in the connection engaging section 55 of the connecting element 5 and the projection on the connection engaging section 17 of the frame element 1 are aligned with each other. The intermediate frame element 1 is pushed up and is released.
The predetermined angle is determined depending upon a feeling on the circumstances or knowledge of use such as the fully open position of the frame element 1, a position midway of the angular movement, or the like.
In connection with the above, it is further convenient if a temporary stop is provided midway of the angular movement and is combined with means for perceiving each position.
Release between the frame elements 1 and the connecting elements 2 can also be done by the following method.
A lower end of the side plate 51, which serves as the convex shaft section 51a within the concave bearing section 15a of the frame element 1, is partially cut out, to form a partial cut-out 51p as shown in FIGS. 2 and 3. A screwdriver may be applied with its forward end abutted against the partial cut-out 51p. A force is applied via the screwdriver with the edge of the flange 15 of the frame element 1 serving as a fulcrum. The side plate 51 is thus elastically deformed, and the convex shaft section 51a is detached from the concave bearing section 15a of the frame element 1.
In another embodiment (not shown), both the ends of the frame element 1 shown in FIG. 1 are cut at 45 degrees. A pair of V-shaped cut-into sections are formed into two intermediate locations from the interior under such a condition that the side plate 18 of the frame element 1 remains to be cut. The pair of cut-into sections are bent into such a configuration that three sides are surrounded. The couplings 5 shown in FIG. 2 are connected respectively to both end faces.
The connecting elements 5 are fitted respectively into the spaces A at both the ends of another frame element 1 which has its length the same as that between the V-shaped cut-into sections. Thus, there is obtained a frame in which only one side of the frame is movable angularly.
In this case, it is also possible to angularly move the angularly-movable frame element 1 whereby the article 3 to be accommodated is drawn from the side face of the frame.
The foregoing will be described further with reference to FIG. 8. The connecting elements g1 and g2 are omitted, and the interior of the single frame element 1 at the positions p1 and p2 are cut into a V-shaped configuration, and are bent.
An assembly, in which the connecting elements g3 and g4 are fitted in both ends of another frame element 1Q, is pushed into the ends p3 and p4 of the frame element, to form a frame.
As shown in FIG. 5, if the lower section of the connecting element 5 projects with respect to a horizontal position of a rear-face section 1a of the frame element 1 to provide a projection 58, it is possible to move the frame element 1 angularly without contact of the lower portion of the rear-face section 1a of the frame element 1 with the wall surface. In this case, it is possible to replace the article 3 to be accommodated by another one, while the connecting element 5 is mounted to the wall surface or the like.
An embodiment illustrated in FIG. 17 is such that a connection engaging inclined surface 117a of a connection engaging section consisting of a fitting bore 117 having its upper section formed narrow, which is provided on the intermediate partition 11 of the frame element 1, is in sliding contact with a connection engaging section 155 which consists of a projection provided on the connecting element 5.
Angular movement of the frame element 1 causes the inclined surface 117a to clamp the connection engaging section 155 of the connecting element 5 at the connection engaging section 117 of the frame element 1, or to release the clamping.
In this embodiment, an inclined surface 352a is provided on a tongue-like spring 352 which is connected to the reinforcing plate 50 and which is formed with a cut groove at its three sides. The inclined surface 352a is engageable with the engaging pawl 13 which is provided on the intermediate partition 11 of the frame element 1.
FIGS. 18 through 20 show an embodiment in the case where a frame element 1 is one in which each end is cut perpendicularly.
The connecting element in the embodiment uses a pair of connecting sections, one being angularly movable, and the other being immovable angularly. A pair of caps 121 are mounted respectively to both the ends of the front-face engaging section 12 of the frame element 1 which is located at the front face of the article 3 to be accommodated.
One of a pair of side plates 251 in the connecting element 5 serves as a spring element when the one side plate 251 is fitted in and engaged with an inside of a flange 215 which is formed at a lower end of one frame element 201.
A bore 217 formed in an intermediate partition 211 of the one frame element 201 serves as a connection engaging section which is capable of being fitted about a projection 255 formed on the one side plate 251 of the connecting element 5.
If the end of the frame element 1 is cut perpendicularly as is in the present embodiment, the corner of the frame element 1 is not brought to a sharp configuration.
Further, since the cap 121 is mounted to the end of the angularly movable frame element 1, it is possible to eliminate a further acute feeling.
The embodiment illustrated in FIG. 21 is one in which the configuration of the frame element 1 is made flat and thin.
In the embodiments illustrated in FIGS. 1 and 18, the space A of the frame element 1 and a holding space B for the article to be accommodated are arranged in the thickness direction of the frame.
Instead, the embodiment illustrated in FIG. 21 is such that the frame element 1 has a top plate 301 connected to the side plate 20, a partition plate 311 is provided on the top plate 301, and the space A and the clamping space B for the article to be accommodated are arranged horizontally.
The article 3 to be accommodated is clamped between a bottom wall 305 and a side wall 306 of the reinforcing plate 50 fitted in the bottom of the connecting element 5 and the front-face engaging section 12 provided on the inner edge of the top plate 301 of the frame element 1.
FIG. 22 shows an embodiment in which an inclined surface 55a for moving the connecting element 5 in the angular-moving axial direction of the frame element 1, accompanied with the angular movement of the frame element 1 illustrated in FIG. 17, is provided on the connection engaging section 55 of the connecting element 5.
In this case, the projection-like connection engaging section 17 of the frame element 1 may be one illustrated in FIG. 1.
FIG. 23 shows an embodiment in the case where the frame elements 1 according to the invention are mounted respectively to the connecting elements 5 formed at an edge of a box.
In the present embodiment, a plurality of pockets 252p are formed at the edge of the box, and a plurality of leaf springs 252 each having an inclined surface 252a are mounted respectively to the pockets 252p.
The inclined surface 252a serves similarly as the inclined surface 152a illustrated in FIG. 2.
FIG. 24 shows an embodiment of a frame which comprises a connecting element and a plurality of frame elements 301. In the connecting element, a plurality of holding projections 7 for the article 3 to be accommodated are formed respectively at the corners of a dish-like rear plate 6. The dish-like rear plate 6 has its edges each of which is provided with an engaging pawl 8 and a finger-catching recess 9' for removing the article 3 to be accommodated. Each of the frame elements 301 is provided with an engaging pawl 13 which is engageable with the engaging pawl 8 of the dish-like rear plate 6.
In this disclosure, there are shown and described only the preferred embodiments of the invention, but, as aforementioned, it is to be understood that the invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.
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A frame, including a plurality of frame elements 1 and at least one connecting corner element 5 on which the frame elements 1 are mounted in intersected relation, is provided to form a readily accessed enclosure to accommodate therein an article, a glass plate to allow viewing of the article, a backing plate at the rear and an illumination louver. At least one of the frame elements 1 is mounted to the connecting corner element 5 for relative angular movement therebetween, to facilitate easy opening of the enclosure and access to the space defined therein.
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TECHNICAL FIELD
[0001] Embodiments of the invention relate to methods of indoor mushroom cultivation, growing or production.
BACKGROUND
[0002] Indoor commercial production of mushrooms allows for tight regulation of growing conditions such as air, temperature and relative humidity while substantially eliminating contaminants and pests. This technique typically employs trays or beds for growing the mushrooms which provides the advantages of scalability and easier harvesting. The trays or beds typically include a substrate such as compost and a casing soil that is disposed above the substrate.
[0003] The casing soil serves as a water reservoir for the mushrooms and a typical watering technique employed includes spraying the beds or trays from above. While using such a spraying technique it is normally required during certain stages of mushroom growth to stop the watering in order to limit the sprayed water from coming into contact with the developing mushrooms. Wet mushrooms may also enhance occurrence of mushroom diseases such as bacterial blotch. At this time, since watering is halted, the water content in the casing and substrate may decrease to below optimal levels.
[0004] PCT Publication No. WO 2006/090965 describes a certain type of drip irrigation tube with scar cuts that are formed on rubber dripping elements. These scars are prevented from direct exposure with the culture medium layer in order to prevent mycelia from being coated in these scar cuts which will clog the exit for water. The ability to effectively add water to the casing layer without wetting the mushrooms may be seen to have the advantages of: adding the needed water to the mushrooms during the entire crop cycle, minimizing the incidence of mushroom diseases, enhancing mushroom quality, and reducing costs of casing and energy.
SUMMARY
[0005] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope.
[0006] The present invention is expressed by the features of the independent claims and aspects. The dependent claims and aspects refer to preferred embodiments.
[0007] Embodiments of the present invention relate to methods for irrigation and cultivating mushrooms using drip irrigation pipes in an indoor environment. By irrigating mushroom with drip pipes as opposed to conventional irrigation with sprinklers, damage to mushrooms may be avoided or limited and irrigation may be performed during longer and more regular intervals.
[0008] In one form of the present invention the method may comprise steps of providing a horizontally extending bed in which a substrate layer and a casing layer that is disposed over the substrate layer are provided. And, the drip irrigation pipes are disposed in the bed preferably in the casing layer.
[0009] In one aspect of the present invention irrigation via the drip irrigation pipes is affected by measurements of water evaporation in the indoor environment outside of the bed. These measurements may derive a value M which may be taken periodically. Possibly these measurements can be taken every N hours with N being either a fraction smaller than 1 hour or any value larger than 1 hour.
[0010] In various forms of the present invention from the measurements of water evaporation an amount of liquid to be irrigated can be derived and irrigated preferably in pulses to the bed and/or mushrooms.
[0011] In one aspect of the present invention the irrigated liquid may be used to maintain a generally constant liquid content in the casing layer while gradually decreasing the liquid content in the substrate preferably compost layer. Possibly relative short liquid pulses optionally with long intervals between pulses may result in an irrigation procedure in which liquid is maintained more in the casing layer and seeps less towards the substrate later below the casing layer. Longer irrigation pulses optionally with shorter intervals between pulses may result in more liquid that is irrigated to the bed that then seeps down towards the substrate layer. Since the preferable compost material of the substrate may physically change over time resulting in its reduced liquid holding capacity—it may be preferable as irrigation proceeds to limit the amount of liquid reaching the substrate layer. And this may be achieved by changing pulse length and time intervals between pulses.
[0012] Further aspects of the present invention will be apparent also from the following numbered aspects:
1. A method of indoor mushroom cultivation comprising the steps of:
providing a horizontally extending bed comprising a substrate layer and a casing layer that is disposed over the substrate layer, and providing drip irrigation pipes that are disposed in the casing layer.
2. The method according to aspect 1, wherein the disposing of the drip irrigation pipes in the casing layer is performed after the casing layer has been disposed over the substrate layer. 3. The method according to aspect 1 or 2, wherein the disposing of the drip irrigation pipes in the casing layer is by urging the drip irrigation pipes into the casing layer. 4. The method according to aspect 3, and comprising a device for urging the drip irrigation pipes into the casing layer, the device being adapted to move in a horizontal direction above the casing layer. 5. The method according to aspect 4, wherein as the device moves above a given portion of the casing layer it urges at least some of the drip irrigation pipes to be disposed into that given portion. In one form this may be performed by providing the device with a slanted sleeve with one upper end located above the bed and a second lower end located within the bed preferable opening into the casing layer. A drip irrigation pipe threaded though the sleeve with its leading end projecting out beyond the lower end of the sleeve, can then be urged into the bed by moving the device horizontally along the bed towards one end of the bed while keeping the pipe's leading end fixed in place to and/or adjacent e.g. another end of the bed. 6. The method according to anyone of the preceding aspects, wherein the drip irrigation pipes are disposed in the casing layer such that their apertures for discharging liquid face substantially the same given direction. This may assist in more accurately controlling where irrigation is provided and reduce possibility of over irrigation that may harm the crop. 7. The method according to aspect 6, wherein the given direction is up. 8. The method according to anyone of aspects 1 to 7, and further comprising a step of irrigating liquid using the disposed drip irrigation pipes, and wherein an amount A of liquid irrigated is determined according to parameters monitored in the indoor environment outside of the bed and parameters monitored in the bed. 9. The method according to anyone of aspect 8, wherein the amount A of liquid irrigated is irrigated in pulses. 10. The method according to aspect 8, wherein the parameters monitored in the indoor environment outside of the bed are associated to at least one of: a bellow communicating air to and from the indoor environment, a shutter controlling communication of air to and from the indoor environment, a temperature gauge measuring the temperature within the indoor environment outside of the bed. 11. The method according to aspects 8 or 9, wherein the parameters monitored in the bed are at least one of: a moisture sensor in the casing layer, a moisture sensor in the substrate layer, a tensiometer in the casing layer, a tensiometer in the substrate layer. 12. The method according anyone of aspects 8 to 11, wherein the liquid irrigated comprises water and/or nutrient amendments. 13. The method according anyone of aspects 8 to 12, wherein the drip irrigation pipes comprise at each aperture in a respective pipe a drip emitter through which liquid passes before being discharged out of the pipe. 14. The method according to aspect 13, wherein each one of the drip emitters has a discharge-pressure threshold greater than zero so that only when local liquid pressure at a location of an emitter in the pipe is greater than zero the emitter will discharge liquid from the pipe. 15. The method according to aspect 14, wherein each one of the drip emitters is a regulated drip emitter that has a discharge rate of liquid out of the pipe that is substantially independent of variations in local liquid pressure at the location of the emitter in the pipe. 16. The method according to aspect 15, wherein the discharge rate of liquid out of the each drip emitter is lower than 1 liter/hour. 17. The method according to aspect 16, wherein the discharge rate of liquid out of each drip emitter is substantiality 0.7 liter/hour. 18. The method according to anyone of aspects 1 to 7, and further comprising a step of irrigating liquid using the disposed drip irrigation pipes, and wherein an amount A of liquid irrigated is determined according to a measure M taken of water evaporation in the indoor environment outside of the bed. 19. The method according to aspect 18, wherein the measure of water evaporation in the indoor environment outside of the bed is taken every N hours. 20. The method according to aspect 19, wherein the determination of the amount A of liquid irrigated is according to A=M×N×F, wherein F is a parameter determined according to the value of M. 21. The method according to aspect 20, wherein K is a threshold parameter of water evaporation, Fu is a first value for F and Fd is a second value for F that is smaller than Fu, and if M >K then F =Fu and otherwise F =Fd. 22. The method according to aspect 21, wherein when M and K are measured in gram to square meter of water. 23. The method according to anyone of aspects 18 to 22, wherein the amount A of liquid irrigated is irrigated in pulses. 24. The method according to anyone of the preceding aspects, wherein the substrate layer comprises compost and the casing layer comprises peat moss and limestone. 25. A method of indoor mushroom cultivation comprising the steps of:
providing a horizontally extending bed comprising a substrate layer and a casing layer that is disposed over the substrate layer, providing drip irrigation pipes that are disposed in the bed, and irrigating liquid using the disposed drip irrigation pipes, wherein an amount A of liquid irrigated is determined according to a measure M taken of water evaporation in the indoor environment outside of the bed.
26. The method according to aspect 25, wherein the measure of water evaporation in the indoor environment outside of the bed is taken every N hours. 27. The method according to aspect 26, wherein the determination of the amount A of liquid irrigated is according to A=M×N×F, wherein F is a parameter determined according to the value of M. 28. The method according to aspect 27, wherein K is a threshold parameter of water evaporation, Fu is a first value for F and Fd is a second value for F that is smaller than Fu, and if M>K then F=Fu and otherwise F=Fd. 29. The method according to aspect 28, wherein when M and K are measured in gram to square meter of water. 30. The method according to anyone of aspects 25 to 29, wherein the amount A of liquid irrigated is irrigated in pulses. In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.
BRIEF DESCRIPTION OF THE FIGURES
[0048] Exemplary embodiments are illustrated in referenced figures. It is intended that the embodiments and figures disclosed herein are to be considered illustrative, rather than restrictive. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying figures, in which:
[0049] FIGS. 1 and 2 show side views of a bed for mushroom cultivation during optional steps of disposal of drip irrigation pipes therein in accordance with an embodiment of the present invention;
[0050] FIG. 3 shows a flow diagram of an algorithm for controlling irrigation of the bed in accordance with an embodiment of the present invention; and
[0051] FIG. 4 shows graphs for substrate and casing layers optimal water content during the mushroom growth cycle when irrigation can be provided.
[0052] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated within the figures to indicate like elements.
DETAILED DESCRIPTION
[0053] Attention is first drawn to FIGS. 1 and 2 . In an embodiment of the present invention, an indoor commercial bed 10 for mushroom cultivation, growth and/or production; may include a tray (not shown) upon which a substrate layer 12 may be laid. Substrate layer 12 optionally consists of compost, and a casing layer 14 optionally consisting of peat moss and/or limestone may be laid upon it. Within the casing layer 14 drip irrigation pipes 16 may be disposed for irrigating mushrooms such as White Button mushrooms/Champignon and Portobello (scientifically named Agaricus bisporus ), Agaricus blazei, Lepista nuda, or the like.
[0054] Typical phases of mushroom cultivation may be defined as: Phase I (composting), Phase II (pasteurization and conditioning), Phase III (Spawning and mycelium growth), Casing, Pinning and harvest. The casing phase is when casing layer 14 is laid upon substrate 12 and after that the irrigation pipes 16 can be disposed into the casing layer 14 . Irrigation from that point can take place during the entire crop cycle, especially during pinning before the first flush (i.e. harvest of mushrooms) and between flushes when spray irrigation is typically avoided. The irrigation can include water and nutrient-amendments.
[0055] For the disposal of the drip irrigation pipes 16 into the casing layer 14 a mechanical device 18 that travels above the bed 10 may be used. Device 18 can be used optionally, by traveling in a horizontal direction H 1 , for spreading the drip pipes 16 upon the bed 10 ( FIG. 1 ), and then in an opposing second horizontal direction H 2 , for disposing the drip pipes 16 into casing later 14 . An optional roller 17 that trails after device 18 as it disposes the drip pipes into the casing layer can be used to slightly compress the casing layer back into place where it was before the insertion of the pipes ( FIG. 2 ).
[0056] In some embodiments of the invention, provision of irrigation to the bed by an irrigation system including the drip irrigation pipes 16 may be controlled in accordance with an algorithm 20 having a flow diagram similar to that shown in FIG. 3 . The flow diagram delineates an optionally diurnal water provision cycle in which the irrigation system provides pulses of water to the bed.
[0057] In a block 22 , optionally values for parameters that control the liquid provision cycle: Tcal, K, Fu and Fd can be determined by optionally being manually inputted by a grower using the irrigation system or his advisor. Tcal is a time during the diurnal cycle at which the irrigation system acquires a measure M of water evaporation in the indoor environment outside of the bed. K is a threshold value of water evaporation, and Fu is a factor used when M is greater than K and Fd is a factor used when M is not greater than K.
[0058] In step 24 algorithm 20 checks a system clock (not shown) to acquire a reading of the time, “Tclock”. In a decision block 26 the time Tclock is checked to see if it is about equal to Tcal. If it is not, then the algorithm returns to block 24 to acquire a new reading for Tclock. If on the other hand Tclock is about equal to Tcal, algorithm 20 advances to a block 28 and acquires a reading of M of the water evaporation in the indoor environment outside of the bed. The algorithm then proceeds to decision block 30 to check if the acquired reading of M is greater than the threshold value K. If it is not, then the algorithm proceeds to block 32 to determine an amount A of water to be irrigated to the bed according to the equation A=M×Tcal×Fd. If on the other hand reading M is greater than the threshold value K then the algorithm proceeds to block 34 to determine the amount A of water to be irrigated to the bed according to the equation A=M×T cal×Fu. After either block 32 or 34 the algorithm proceeds to a block 36 where T clock is initialized to zero and from there the algorithm returns to decision block 26 to start a consecutive cycle that will lead to a consecutive irrigation cycle.
[0059] The needed water amount A, may be divided into pulses of irrigation, that are provided at optionally given time intervals, until the amount A has been fed to the bed.
[0060] By way of an example, a mushroom production bed may be sized and equipped such that it has: a width of 1.3 meters, a length of 24 meters, 8 drip lines that are disposed in parallel in the casing layer, with about 6 drip emitters per meter length having each a regulated discharge rate of 0.7 liter/hour. In such a setup, Tcal can initially be set to 5 hours, K can be equal to 40 gram/m 2 , Fu can be equal to 2 and Fd can be equal to 1.3. Following this example, If a measure M of the water evaporation in the indoor environment outside of the bed is equal to 50 gram/m̂2 then A=50×5×2=500 gram (i.e. 0.5 liter). This amount can be divided into pulses of 0.25 liter that are provided twice to the bed with a time difference of optionally 2 hours between the pulses. If on the other hand the measure M is equal to 30 gram/m̂2 then A=30×5×1.3=195 gram (i.e. about 0.2 liter), and this amount can optionally be divided into pulses of 0.1 liter that are provided twice to the bed with a time difference of 2 hours between the pulses.
[0061] In experiments conducted by the inventors, it was demonstrated, that while typical casing layer thickness of 5.5 centimeters is used, when conventional spray irrigation is provided, with drip irrigation, it was possible to reduce the thickness of the casing layer to 3.2 centimeters, without harming the yield or the quality of the mushrooms. Attention is now drawn to FIG. 4 that shows optimal water content graphs, for the substrate and casing layers that are applicable to certain conditions and certain bed configurations that were tested by the inventors. It has been found over a period of time, during which drip irrigation can be provided, that the casing layer's water content may optimally be kept during the entire crop cycle at the needed level. With respect to the substrate (i.e. compost), on the other hand, it has been found that its water content may optimally be reduced over the same period due to physical degradation that the substrate undergoes which decreases its water holding capacity. Optionally, for conditions in a bed to substantially follow this water content pattern, it has been found that shorter pulses of water tend to affect more the humidity of the casing layer while longer pulses affect also the humidity of the substrate (compost) layer. As a result, as the production of mushrooms progresses and time passes the average length of the pulses may become shorter in order to substantially maintain the same level of humidity in the casing while reducing water content of the compost.
[0062] In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.
[0063] Although the present embodiments have been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the scope of the invention as hereinafter claimed.
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For indoor mushroom cultivation, a method of irrigating the mushrooms includes drip irrigation pipes in the bed. The drip irrigation pipes can be disposed in a casing layer that overlies a substrate layer, and irrigation can be according to measurements taken in the environment outside of the bed.
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The present invention relates to a toolkit for balancing the load of an application distributed among several machines belonging to a distributed data processing system in a local area network.
FIELD OF THE INVENTION
The current trend in the development of data processing systems is to form a data processing system through the association of a plurality of machines connected to one another through a network for example a local area network. Any user can run applications of widely varied types on this set of machines. These applications call services which supply the information required to handle the problem or problems they are working on, which are offered by all or some of these machines.
When an application in the process of running requires the use of a particular service, in current practice, it proceeds in the following manner:
either it chooses, in a purely random manner, the machine which will provide it with this service and assigns the work to this machine,
or it makes a circular choice among all the machines, which means that it assigns by turns, always in the same chronological order, the work of providing the services it requires in succession: thus, if the system has three machines, it assigns the work of providing the services it requires first to machine No. 1 , those it requires second to machine No. 2 , those it requires third to machine No. 3 , and so on in the following order: No. 1 , No. 2 , No. 3 , No. 1 , etc.
No matter which of the two cases described above applies, none of the work of any of the machines is optimized in terms of time, and the capabilities of these machines in terms of speed and performance are used only at a level far below their maximum.
There are some known solutions which make it possible to eliminate these drawbacks: one of these is described in French patent application No. 94 08764, filed Jul. 13, 1994 by the Assignee of the subject application, under the title “Open Data Processing System with Multiple Servers”. In a system of this type, formed by the association of a central system called a client with several servers, each server calculates its own load based on the criteria specific to each application running on the client, as well as its foreseeable development over time, and transmits these two factors to the client. The latter, when a particular application requires the services of a server, chooses the one with the lightest load during the period of time in which the services must be rendered and assigns it the work of supplying the services requested.
SUMMARY OF THE INVENTION
The present invention constitutes an improvement and a generalization of the preceding solution.
According to the invention, the tool at the service of a distributed application running on the machines of a distributed data processing system in a local area network, which is intended for balancing the load on each of these machines, is characterized in that it comprises a plurality of data processing modules called DAEMONs which run on these machines, one of which is called the master, the others being agents,
the master and the agents each having means for calculating the load of the machines on which they are running, at first predetermined sampling instants, and means for storing the load data of the master and the agents,
the master containing:
means for collecting the load data of each agent, at second predetermined sampling instants,
means for sending the load data of each agent to all of the other agents,
each agent containing:
means for receiving the load data of the other agents,
the local agent closest to the application indicating to the latter, at the request of the latter, the machine with the lightest load, the application then making the decision to request this machine to execute the services it needs.
BRIEF DESCRIPTION OF THE DRAWING
Other characteristics and advantages of the present invention will become apparent from the following description given as a non-limiting example in reference to the appended drawings. In these drawings:
FIG. 1 shows a distributed data processing system which includes the load balancing toolkit according to the invention.
FIG. 2 shows the controller for distributing the master-agent roles among the various elements which constitute the load balancing toolkit according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
1) ESSENTIAL CHARACTERISTICS OF THE TOOL ACCORDING TO THE INVENTION
A) Structure:
The various essential characteristic elements of the load balancing toolkit ORC for (load balancing toolkit, in English) (load balancing toolkit, in English) in a distributed data processing system according to the invention—for simplicity's sake, from this point forward, it will be called the “toolkit”—appear in FIG. 1 .
As shown in FIG. 1, the distributed data processing system, which can be any type whatsoever, here called SID, comprises four data processing machines of any size and shape whatsoever, namely MCO, MC 1 , MC 2 , MC 3 . Each of these machines—small-, medium, or large-scale computers—comprise the usual elements, namely one or more central processor unit, called CPU , memories associated with the latter, input/output units (I/O units,) and means for connecting to the network RE. These means are symbolically represented by two-way arrows which represent the data links between the four machines MCO through MC 3 in FIG. 1 .
The toolkit ORC itself comprises the master MS 0 and the three agents A 1 , A 2 , A 3 . Any agent can also be a master, depending on conditions which will be explained below. Both the master and the agents are constituted by data processing tools known to one skilled in the art as DAEMONs. A DAEMON is a data processing tool or entity running on a machine, which is capable of responding to a question.
Inside each of the machines MCO through MC 3 , the DAEMONs MS 0 , A 1 , A 2 , A 3 are respectively associated with shared memories MPO, MP 1 , MP 2 , MP 3 . Each of them contains the load of the corresponding machine, but also the loads of the other machines in SID.
FIG. 1 assumes that the distributed application is running on the machine MC 2 and that it requires services supplied by the other machines MCO, MC 1 , MC 3 . This application is designated APU. The places where the master and the agents are located are independent from the place where APU is running.
B) Operation:
The following are the main lines of operation of the tool ORC, it being understood that during the establishment of communication between all the machines in the system SID, it is assumed to be established that MS 0 is the master and that A 1 , A 2 , A 3 are the agents. Refer again to FIG. 1, and specifically to the arrows and the circled numbers which accompany them, which respectively indicate the direction of the information flowing between the master and the agents, and the sequence of operations.
OPERATION 1: Each agent as well as the master collects, for the machine on which it is running, at given time intervals which constituted the first determined sampling instants ti, the load data of this machine, for each of the elements which constitute it (the CPU load, the loads of the associated memories, the loads of the I/Os, the network load, etc.). From the load of each element, expressed as a percentage of its maximum allowable load, the total load of the machine in question is calculated. This is accomplished by load calculation means, respectively MCC 0 for MS 0 , MCC 1 for A 1 , MCC 2 for A 2 , MCC 3 for A 3 . These means are simply constituted by calculation programs which implement the load calculation method described below, in paragraph 2: “Method for load calculation by each of the agents.”These means are naturally an integral part of the master and of each agent, MS 0 , A 1 through A 3 and for this reason they are not represented per se in FIG. 1, for simplicity's sake. Once the total load of the machine in question is calculated a set of statistical data on the load of this machine, namely DSC, is obtained. In FIG. 1, this operation is shown for the agent A 2 only, obviously for the purpose of preserving the clarity of this figure.
OPERATION 2: At regular intervals, the agents send MS 0 the statistical load data from the corresponding machine, through the network (for A 2 , through the link L 2 between MC 2 and MC 0 ).
OPERATION 3: The master MS 0 centralizes, at practically the same regular intervals defined for Operation 2 , which constitute the second determined sampling instants Ti, all the statistical load data of all the agents, as well as its own, at the level of its associated shared memory, in this case MP 0 . This centralization is in fact an operation for collecting the load data. It is therefore executed by load data collection means, respectively MRC 0 for MS 0 , MRC 1 for A 1 , MRC 2 for A 2 , MRC 3 for A 3 , which are in fact collection programs integrated into the master and into each of the agents A 1 through A 3 and are therefore not represented in FIG. 1 for simplicity's sake.
OPERATION 4: The master MS 0 sends, using sending means MTCO, all this data to each agent A 1 , A 2 , A 3 through the network RE, namely through the links L 1 between MC 0 and MC 1 , L 2 between MC 0 and MC 2 , L 3 between MC 0 and MC 3 , MTC 0 is an integral part of MS 0 and is therefore not represented in FIG. 1 for simplicity's sake.
OPERATION 5: Each agent receives this load data and copies it into its associated shared memory. MP 1 for A 1 , MP 2 for A 2 , MP 3 for A 3 . This is accomplished by the means MRCC 1 through MRCC 3 for A 1 through A 3 respectively, which means are integral parts of the latter and are not represented in FIG. 1 for simplicity's sake.
OPERATION 6: The application APU scans the shared memory of the machine on which it is running to search it for the load estimated for each of the machines, and at the moment it needs the determined services to be rendered, it deduces the machine with the lightest load at this moment and requests the latter to render it these services.
2) METHOD FOR LOAD CALCULATION BY EACH OF THE AGENTS:
Examples of loads on the CPU, memory, Input/Output, and network RE elements are described below.
The description of the method for load calculation by each of the means MCCO through MCC 3 is given in reference to Tables 1 through 4, which appear below and in which the loads are given as percentages.
TABLE 1
Sample load data
stored in any shared memory associated with an agent (expressed as a %)
t1
t2
t3
t4
t5
t6
t7
CPU load (W1)
35
12
42
73
92
65
33
Memory load (W2)
45
32
33
67
46
32
40
Network load (W3)
12
6
33
20
12
38
5
Input/output load (W4)
25
30
56
46
78
44
32
TABLE 2
synthesis of series of global load data for each machine
t1
t2
t3
t4
t5
t6
t7
MC0
56
32
67
63
79
82
54
MC1
23
34
45
56
67
62
79
MC2
32
38
34
42
35
32
36
MC3
96
94
79
82
74
79
68
TABLE 3
extrapolation
of the value of the global load after a time T for each machine
t1
t2
t3
t4
t5
t6
t7
t8 = t7 + T
MC0
56
32
67
63
79
82
54
estimated 73
MC1
23
34
45
56
67
62
79
estimated 82
MC2
32
38
34
42
35
32
36
estimated 36
MC3
96
94
79
82
74
79
68
estimated 73
TABLE 4
application of the power coefficient, comparison and selection
MC0
MC1
MC2
MC3
Estimated capacity
73
82
36
76
Power coefficient
2.5
2
0.8
1.5
Coefficient of the available
67.5
36
51.2
36
capacity
(100 − estimated load) *
power coefficient
The calculation of the load for each agent and master is identical to that described in the above-mentioned patent. It is briefly summarized here.
The total load Wt of an agent (and also of the master) is obtained using the following formula:
Wt=k1*W1+k2*W2+k3*W3+k4*W4, in which:
W 1 is the percentage of the utilization of the central processor of the agent in terms of time,
W 2 is the percentage of the utilization of the memory of the agent, that is, the ratio between the storage capacity actually used and its total capacity,
W 3 is the percentage of the utilization of the network by the agent, that is, the ratio between the number of pieces of information sent and received by the agent and the maximum allowable rate in the network,
W 4 is the percentage of the utilization of the input/output units by the agent.
k 1 , k 2 , k 3 , k 4 are specific weighting factors of the processor, the memory, the network, and the input/output units. Their sum is equal to 1. Their values depend on the nature of the application in the process of running, in this case APU on the machine MC 2 .
The loads W 1 , W 2 , W 3 , W 4 are measured and Wt is calculated as shown in each of the tables in Appendix 1, at determined sampling instants t1, t2, t3, t4, t5, t6, t7, etc. of the period T (which are, in fact, the instants ti mentioned above in the description of Operation 1).
Table 1 gives an example of load data collected by any agent, for example A 1 , relative to the corresponding machine MC 1 , for all the instants t1 through t7. This data is, of course, stored in the shared memory MP 1 of the machine MC 1 on which A 1 is running, before it is sent to MS 0 .
This table shows, for example, that W 1 is equal to 35 at the instant t1, W 2 to 67 at the instant t4, W 3 to 38 at t6, W 4 to 32 at t7, and so on.
A calculation program API associated with APU, which runs on MC 2 , then applies—for the load data of each agent and the master which, after the execution of Operation 3, is contained in the shared memory MP 0 of MC 0 associated with MS 0 —the weighting factors k 1 through k 4 specific to the corresponding machines for the application APU.
Thus Table 2 is obtained, which shows, for each of the machines MCO through MC 4 , the global load value Wt at the instants t1 through t7. Thus it may be seen that, for MC 0 , Wt is equal to 56 at the instant t1, 32 at t2, 67 at t3, etc. For MC 1 , Wt is equal to 23 at t1, 34 at t2, etc., and so on for the other machines.
The following step for calculating the load for all the machines consists of estimating, by extrapolation, using the known mathematical method of least error squares, the value of the estimated load Wt at the instant t8=(t7+T).
Thus, Table 3 is obtained. This table makes it possible to read, for example, that the estimated values of the loads of MCO through MC 3 at this instant t8 are 73, 82, 36, and 76, respectively.
Next, a power coefficient Cp specific to each machine is applied to the total load of each machine in order to obtain its actual available capacity rate C 1 , using the formula:
C1=(100−Wt(estimated))*Cp
In effect, it is important to take into account the characteristics of each machine, given that this is a heterogeneous data processing environment wherein the power, the size and the type of the machines which compose it are different. Thus, if a machine has a light load but at the same time does not have enough processing power to provide the services requested of it by the application APU at a given moment, it is obvious that another machine must provide these services. Hence the necessity for a correction factor in order to define the load, and hence the existence of the power coefficient CP which corresponds to this purpose.
The coefficient Cp of a given machine is calculated by generating a synthesis of the power of the central processor CPU, the capacity of the memories, the processing power of the input/output units, etc. It is recalculated each time the hardware configuration of the machine is changed or its operating system is modified. Likewise, each time the general configuration of the distributed data processing system SID is changed, all the coefficients CP of all the machines in the system are redefined. A Cp equal to 1 corresponds to a medium-scale machine, which is defined by the user.
In Table 4, it is possible to read examples of actual available capacity rates C 1 for each machine MCO through MC 3 . Thus, for MCO, with an estimated capacity rate of 73 and a power coefficient Cp of 2.5, the actual available capacity rate is 67.5. The same figures are respectively 82, 2, 36 for MC 1 , and so on for MC 2 and MC 3 .
3) METHOD FOR SELECTING THE MASTER MS 0 :
The basic philosophy is that any DAEMON running on any machine can be a master. It is therefore important to develop a mechanism which makes it possible to define which one of them will be the master and the conditions for its selection, as well as the modalities for its replacement should it fail.
The selection mechanism must ensure that at least 1 DAEMON is running and that two of them cannot be masters simultaneously (especially if they start up at the same time).
It is composed of the following 5 main phases:
Phase 1: When a DAEMON starts up, it generates a unique identifier ID in conformity with the protocol used in the network RE, for example in conformity with the TCP-IP protocol used in the exemplary embodiment of the invention described herein. This identifier is composed of the Ethernet address (Ethernet is the part of the TCP-IP protocol related to local area networks and is used in the exemplary embodiment described herein. Ethernet being understood to be standardized and therefore known to one skilled in the art), the moment at which the identifier is transmitted, and a random value. At the same time, it puts itself into an intermediate state and sends these two pieces of information (its current state, ID) through the network RE to all the machines in the network.
Phase 2: it waits to receive the identical information from the other DEMONS, for determined a time interval Tr (on the order of 5 to 10 seconds). It is a candidate for the role of master.
Phase 3: As soon as it receives this information, it analyzes it.
If it comes from a DAEMON which is in fact a master, that is, considered to be MS 0 , it considers itself to be an agent.
If it comes from a DAEMON in an intermediate state, it compares its own identifier with the one it receives.
If its own identifier is lower than the one it receives, it retains the right to be the master MS 0 .
If its own identifier is higher than or equal to the one it receives, it cedes the position. It then retransmits the two pieces of information (its own ID, its state) and again waits for responses during the time interval Tr, also called the timer.
Phase 4: Once this time interval has elapsed, the DAEMON in question tries again. In order to avoid a loss of messages, which is always possible in the network RE, it uses the following procedure:
The transmission and the listening for responses are repeated 5 times.
If the DAEMON in question receives a response from another DAEMON which reveals itself to be an agent, it can be sure that a master MS 0 exists and it waits for the response from the latter to reach it.
Phase 5: When 5 repetitions have taken place, and the DAEMON in question has not received any response from the other DAEMONs, it then decides that it is the master MS 0 .
When one of the three agents A 1 through A 3 realizes that the master MS 0 is no longer communicating with it, it starts the procedure below in all its phases, which results in the choice of a new master chosen from among the three.
Moreover, the master periodically notifies all the machines in the system SID of its existence. If the master detects the existence of another master, the procedure is restarted by the one whose ID is lower.
FIG. 2, which shows the controller AUT which distributes the master-agent roles among the various DAEMONs running on the machines of SID, will make it easier to understand the sequence of the different phases 1 through 5 described above.
This controller AUT comprises 5 states:
State IO: The DAEMON in question sends the two pieces of information (its own ID, its state), which corresponds to Phase 1 .
State I 1 : This DAEMON listens for responses from the other DAEMONs, which corresponds to Phases 2 and 3 .
State I 2 : This DAEMON waits for the time interval Tr to elapse, and for a possible response from the master MS 0 .
State A: The DAEMON in question becomes an agent A 1 , A 2 or A 3 .
State M: The DAEMON in question becomes the master MS 0 .
The events which correspond to this controller, which are denominated e 1 through e 8 , are the following:
e1: The DAEMON in question has disseminated its ID and its state and has set a time interval Tr.
e2: An ID is received, and the local identifier ID (that of the DAEMON in question) is lower than the identifier it receives.
e3: An ID is received, and the local ID is greater than or equal to the ID received.
e4: The time interval Tr has expired.
e5: The time interval Tr has expired and the number of attempts is less than 5, or an agent has just responded.
e6: The master has just responded.
e7: The time interval Tr has expired, the number of attempts is equal to 5, and no agent has responded.
e8: The connection with the master is lost.
e9: Detection by a master of the existence of another master with a higher ID.
While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth herein, are intended to be illustrative, not limiting. Various changes may be made without departing from the true spirit and full scope of the invention as set forth herein and defined in the claims.
APPENDIX 1
TABLE 1
Sample load data
stored in any shared memory associated with an agent (expressed as a %)
t1
t2
t3
t4
t5
t6
t7
CPU load (W1)
35
12
42
73
92
65
33
Memory load (W2)
45
32
33
67
46
32
40
Network load (W3)
12
6
33
20
12
38
5
Input/output load (W4)
25
30
56
46
78
44
32
TABLE 2
synthesis of series of global load data for each machine
t1
t2
t3
t4
t5
t6
t7
MC0
56
32
67
63
79
82
54
MC1
23
34
45
56
67
62
79
MC2
32
38
34
42
35
32
36
MC3
96
94
79
82
74
79
68
TABLE 3
extrapolation
of the value of the global load after a time T for each machine
t1
t2
t3
t4
t5
t6
t7
t8 = t7 + T
MC0
56
32
67
63
79
82
54
estimated 73
MC1
23
34
45
56
67
62
79
estimated 82
MC2
32
38
34
42
35
32
36
estimated 36
MC3
96
94
79
82
74
79
68
estimated 73
TABLE 4
application of the power coefficient, comparison and selection
MC0
MC1
MC2
MC3
Estimated capacity
73
82
36
76
Power coefficient
2.5
2
0.8
1.5
Coefficient of the available
67.5
36
51.2
36
capacity
(100 − estimated load) *
power coefficient
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A tool at the service of a distributed application running on machines of a distributed data processing system running in a local area network, intended for balancing the load on each of the machines of the system, includes a master daemon and a plurality of agent demons. The master and each of the agents calculate the load of the machine on which they are running. The master collects the load data of each of the agents at a first sampling interval and sends that collected load data to all of the agents. At the request of the distributed application, the local agent closest to the application indicates to the application which machine has the lightest load. The application then makes the decision to request the machine with the lightest load to execute the services the application requires. As necessary, the tool selects a master from the agents, thereby ensuring the existence and uniqueness of a master at all times, regardless of failure affecting one 1010 or more machines in the data processing system.
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FIELD OF THE INVENTION
In one aspect, the present invention relates to devices for obtaining subterranean material samples. In another aspect, the present invention relates to devices for retaining subterranean material samples in sampler housings. In yet another aspect, the present invention relates to methods for obtaining subterranean material samples.
BACKGROUND OF THE INVENTION
Cone penetrometer systems are commonly used for analyzing subterranean materials and conditions and for developing stratigraphic maps. Recently, cone penetrometer systems have been used in addressing underground contamination problems. Through subsurface analysis, sample recovery, and mapping, cone penetrometer systems have been used to determine the existence and nature of underground contamination problems and to evaluate possible solutions.
A cone penetrometer system will typically utilize a long tubing string having a sensing tool, a sampling tool, and/or some other type of tool positioned on the end thereof. The tubing string is preferably driven, without drilling or turning, into the ground using a hydraulic ram. In some applications, the tubing string is driven 300 or more feet into the ground. For convenience, the hydraulic ram is typically included on a cone penetrometer truck.
In conducting a cone penetrometer test, a relatively small diameter tubing string having a cone on the end thereof is typically driven into the ground first. The cone can be equipped with electronic sensors which take seismic readings and measure such parameters as: the frictional forces encountered by the tubing string; pore water pressure; temperature; inclination; and resistivity. This data is processed and interpreted to obtain a complete stratigraphic map of the test site. Once the stratigraphic data is obtained, the small diameter tubing string is typically pulled out of the ground.
Next, a tubing string having a sample retrieving tool positioned on the end thereof is typically driven into the ground. Sample retrieving tools can be used to obtain underground soil and/or water samples from any particular zone of interest.
The soil sampling tool used heretofore is composed generally of: a sample barrel for collecting the sample material; a rod having one end attached to the end of the penetrometer tubing string; and a tapered driving tip attached to the other end of said rod. As the soil sampling tool is driven into the ground, the rod extends through the sample barrel such that the base end of the sample barrel abuts the end of the tubing string and the driving tip projects from, and blocks, the forward end of the sample barrel. The outside diameter of the base of the driving tip is slightly smaller than the inside diameter of the sample barrel so that the driving tip can be retracted from the forward end of the sample barrel to the base of the sample barrel.
When the soil sampling tool reaches a desired underground sampling location, the penetrometer tubing string is pulled from the ground a sufficient distance to retract the driving tip from the forward end of the sample barrel to the base end of the sample barrel. As the tubing string is being pulled from the ground in order to retract the driving tip, the sample barrel is held at a fixed position in the ground by soil which has compacted around the sample barrel as a result of the driving operation. When the driving tip reaches the base end of the sample barrel, the driving tip and rod automatically lock in place so that the rod can be used to push the sample barrel, which is now open to receive the underground material sample, deeper into the formation. As the sample barrel is pushed deeper into the formation, soil is forced into the forward end of the sample barrel. After the sample barrel has been filled with sample material, the sample barrel is pulled from the ground.
The above-described soil sampling tool is designed primarily for use in stratigraphic analysis rather than environmental analysis. Specifically, the tool is designed primarily to allow the recovery and visual classification of underground soil samples.
The above-described soil sampling tool has numerous shortcomings, particularly when used for collecting samples for environmental analysis. For example, the tool's driving tip does not completely seal the forward end of the sample chamber; consequently, material, e.g., water and/or soil, from other formations enters and contaminates the sample chamber as the sampling tool is driven into the ground. Additionally, since the forward end of the sample barrel must remain open after the sample is taken, unconsolidated sample material can simply fall out of the forward end of the sample barrel as the sample barrel is pulled from the ground. Further, the sample barrel does not hold a sufficient quantity of sample material for the performance of a complete environmental analysis. In order to obtain a quantity of sample material sufficient for a complete environmental analysis, the sampling tool must be driven into and withdrawn from the ground numerous times.
Previous attempts to increase the size of the sample barrel have been largely unsuccessful. Substantially increasing the size of the sample barrel greatly increases the amount of stress encountered by the rod member when said rod member is used to drive the sample chamber deeper into the ground. Further, any increase in the length of the sample chamber must be matched by a corresponding increase in the length of the rod member. However, it has been found that any substantial increase in rod member length greatly increases the risk of rod member breakage.
In addition to the above, it has not been possible heretofore to obtain a continuous core sample using a cone penetrometer system. As indicated, any significant increase in sample chamber length must be matched by a corresponding increase in rod member length. Thus, increasing the length of the sample chamber renders the rod member extremely vulnerable to breakage. Consequently, the collection of a continuous core sample from a depth exceeding about 10 feet has heretofore required the use of a drilling system.
SUMMARY OF THE INVENTION
The present invention provides an apparatus and a method for obtaining a subterranean material sample. The inventive method comprises the step of inserting the inventive apparatus into the ground. The inventive apparatus comprises: an elongate housing having a passageway extending longitudinally therethrough; a tip member; and a locking means. The elongate housing has a first end and a second end. The passageway extending through the housing has a first portion and a second portion, said first portion being closer than said second portion to the first end of the elongate housing. The tip member is positionable in the second portion of the passageway such that the tip member protrudes from the second end of the housing. The tip member is movable in the passageway from the second portion of the passageway to the first portion of the passageway. The locking means releasably prevents the tip member from moving from the second portion of the passageway to the first portion of the passageway. The inventive apparatus preferably further comprises a sealing means, associatable with the tip member, for sealing the passageway when the tip member is positioned in the second portion of the passageway.
The present invention also provides a device for retaining material in a housing. The device comprises a plurality of resilient petal members which will open to allow the material to pass therethrough into the housing. However, the petal members will resiliently close to prevent the sample material from passing therethrough out of the housing.
In contrast to the soil sampling tools and methods used heretofore, the present invention allows the in-depth collection of a continuous core sample using a cone penetrometer system. Using only a single insertion of the inventive apparatus, a sufficient quantity of sample material can be obtained from a given underground location for the performance of a complete environmental analysis. Additionally, the passageway extending through the housing of the inventive apparatus is sealed as the inventive apparatus is driven into the ground; consequently, the present invention substantially eliminates the abovedescribed contamination problems. Further, the present invention provides means for preventing sample material from falling out of the inventive apparatus as the apparatus is withdrawn from the ground.
Further objects, features, and advantage of the present invention will be readily apparent to those skilled in the art upon reference to the accompanying drawings and upon reading the following description of the preferred embodiments.
DESCRIPTION OF THE DRAWINGS
FIG. 1 provides a cutaway side view of an embodiment of the sampling apparatus of the present invention.
FIG. 2 provides a top cutaway view of the inventive sampling apparatus taken along line 2--2 depicted in FIG. 1.
FIG. 3 provides an enlarged side view of a portion of the sampling apparatus depicted in FIG. 1.
FIG. 4 provides a side view of an embodiment of the sample holding device of the present invention.
FIG. 5 provides a top view of the inventive sample holding device.
FIG. 6 provides a cutaway side view of a second embodiment of the sampling apparatus of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Depicted in FIGS. 1-3 is an embodiment of the sampling apparatus 2 of the present invention. Apparatus 2 comprises: an adapter 4; one or more sample tubes 6; a tip holder 8; and a cutting member 10. Adapter 4, sample tube(s) 6, tip holder 8, and cutting member 10 define a housing having a passageway 12 extending longitudinally therethrough. Apparatus 2 further comprises a tip retainer 14, a sample holder 16, locking keys 18, a tip member 20, and a tip locking member 22.
As depicted in FIG. 1, adapter 4 is a tubular member having an internally threaded portion 24 at one end thereof for connecting apparatus 2 to the end of a penetrometer tubing string. Adapter 4 has an externally threaded portion 26 at the other end thereof for connecting adapter 4 to a sample tube 6. O-ring 28 is positioned at the base of externally threaded portion 26 for sealing the connection between adapter 4 and sample tube 6. As will be apparent to those skilled in the art, the internal and external diameters of the various portions of adapter 4 can be varied as necessary for connecting apparatus 2 to penetrometer tubing strings having outside diameters which are smaller than, larger than, or equivalent to the outside diameter of sample tube(s) 6.
Each sample tube 6 is a tubular member having an internally threaded portion 30 at one end thereof and an externally threaded portion 32 at the other end thereof. Each sample tube preferably has a length in the range of from about 12 to about 13 inches. Depending upon the amount of sample and/or the length of sample core desired, any number of serially connected sample tubes 6 can be included in apparatus 2. The internally threaded portion 30 of the first sample tube 6 is connected to the externally threaded portion 26 of adapter 4. The externally threaded portion 32 of the last sample tube 6 is connected to tip holder 8. An O-ring 34 is positioned at the base of each externally threaded portion 32 in order to seal the connection between the serially connected sample tubes 6 and between the last sample tube 6 and tip holder 8.
Tip holder 8 comprises: an internally threaded portion 36 for connecting tip holder 8 to the last sample tube 6; an annular interior lip 38, adjacent internally threaded portion 36, having an abutment surface 40; a cylindrical interior bore portion 42 adjacent lip 38; a cylindrical interior bore portion 44 having an internal diameter less than that of bore portion 42; an interior bore portion 46 extending from cylindrical bore portion 42 to cylindrical bore portion 44, said bore portion 46 defining a frusto-conical interior surface 48; a cylindrical interior bore portion 50 adjacent bore portion 44 and having an interior diameter less than that of bore portion 44; and a shoulder 52 defined by the transition from bore portion 44 to bore portion 50. Tip holder 8 further comprises a frusto-conical exterior surface 54, for facilitating the insertion of apparatus 2 into the ground, and an externally threaded portion 56 for connecting tip holder 8 to cutting member 10.
Cutting member 10 comprises: an internally threaded portion 58 for connecting cutting member 10 to tip holder 8; a cylindrical interior bore portion 60, adjacent portion 58, having an internal diameter substantially equivalent to the internal diameter of bore portion 50 of tip holder 8; a frusto-conical exterior surface 62; and a circular cutting edge 64 defined by the intersection of frusto-conical exterior surface 62 with the interior surface of bore portion 60.
Tip member 20 comprises a conically-shaped driving tip 66; a cylindrical portion 68, adjacent the base of conically-shaped driving tip 66, having an outside diameter equivalent to the outside diameter of the base of tip 66; a cylindrical end 70, adjacent cylindrical portion 68, having an outside diameter less than the outside diameter of cylindrical portion 68; and a shoulder 72 defined by the transition from cylindrical end 70 to cylindrical portion 68. A threaded bore 74 is provided in cylindrical end 70 of tip member 20 for connecting tip member 20 to tip locking member 22.
Tip locking member 22 comprises a first cylindrical portion 76 and a second cylindrical portion 78. First cylindrical portion 76 has a larger exterior diameter than second cylindrical portion 78. The exterior diameter of second cylindrical portion 78 is substantially equivalent to the exterior diameter of cylindrical portion 68 of tip member 20. A shoulder 80 is defined by the transition between cylindrical portion 76 and cylindrical portion 78. A cylindrical bore 82 is provided in the end of second cylindrical portion 78. The inside diameter of cylindrical bore 82 is slightly greater than the exterior diameter of cylindrical end 70 of tip member 20 so that cylindrical end 70 can be received within cylindrical bore 82. The end of first cylindrical portion 76 is provided with a cylindrical bore portion 84 and a frusto-conical bore portion 86. Bore portion 84, and bore portion 86 define a recess 85 in the end of tip locking member 22 for receiving keys 18 when apparatus 2 is unlocked. Cylindrical bore portion 84 defines a rim 88 on the end of cylindrical portion 76 on which keys 18 are positioned when apparatus 2 is locked. A bore 90 runs longitudinally through tip locking member 22 and is provided for connecting tip locking member 22 to tip member 20 using bolt 92.
An O-ring 94 is positioned between tip member 20 and tip locking member 22 as shown in FIGS. 1 and 3. O-ring 94 is compressed between tip member 20 and tip locking member 22 as tip member 20 is driven into the ground. O-ring 94 is preferably sized such that, during the driving operation, O-ring 94 is urged snugly against the interior surface of cylindrical bore portion 50 of tip holder 8 and thereby effectively seals passageway 12.
As shown in FIGS. 1-3, keys 18 are preferably pie-shaped pieces which are positionable between abutment surface 40 and rim 88. Each key preferably has a lip portion 96 which extends partially into recess 85 when keys 18 are positioned on rim 88. Apparatus 2 utilizes at least one key 18. Apparatus 2 preferably utilizes at least two keys 18. Apparatus 2 most preferably utilizes three keys 18 as shown in FIG. 2. Projections 89 are preferably provided on rim 88 for positioning and spacing keys 18 on rim 88 and for limiting the radial movement of keys 18.
As is apparent in FIGS. 1-3, the clearances (a) between annular lip 38 and the cylindrical portion 76 of tip locking member 22 and (b) between cylindrical portion 76 and the remaining portions of tip holder 8 below annular lip 38 are insufficient to allow locking keys 18 to fall to the outside of cylindrical portion 76. Consequently, when keys 18 are positioned as shown in FIGS. 1-3 and tip locking member 22 is urged upward in tip holder 8 (i.e., toward adapter 4), keys 18 are caught between rim 88 and lip 38 such that rim 88 binds against keys 18 and tip locking member 22 is thus prevented from moving through lip 38. However, when tip locking member 22 is lowered in tip holder 8 (i.e., when shoulder 80 of tip locking member 22 is moved toward shoulder 52 of tip holder 8), the outside ends of keys 18 contact frusto-conical surface 48 and are pushed by surface 48 into recess 85. With keys 18 thus positioned in recess 85, tip locking member 22 can subsequently move freely through annular lip 38.
Sample holder 16 is illustrated in FIGS. 1 and 3-5. Sample holder 16 comprises: a cylindrical portion 98; an outwardly extending lip 100 at the base of cylindrical portion 98; and a plurality of resilient petal members 102 extending upwardly and inwardly from the other end of cylindrical portion 98. The outside diameter of cylindrical portion 98 is slightly less than the inside diameter of sample tube(s) 6 so that sample holder 16 can be received within the male threaded end of sample tube 6. Sample holder 16 is held in place in apparatus 2 by lip 100 which is positionable between the male end of sample tube 6 and the female end of tip holder 8 in the manner shown in FIGS. 1 and 3.
Sample holder 16 can be formed, for example, by: (1) fabricating a thin-walled, cylindrical, 304 stainless steel member 104 having a lip 100 at the base thereof; (2) cutting a petal pattern 106 from a thin sheet of beryllium copper spring flex material, said pattern 106 having a rectangular portion and a plurality of petals 102 extending from one long side of the rectangular portion; (3) wrapping the rectangular portion of petal pattern 106 around the outside of cylindrical ring member 104; (4) attaching the rectangular portion of petal pattern 106 to ring member 104 by resistance welding; (5) bending petals 102 inwardly to the positions shown in FIGS. 4 and 5; (6) heat treating the sample holder 16 at about 600° F. for about one hour; and then (7) air quenching the sample holder.
Resilient petal members 102 of sample holder 16 flex open to allow tip locking member 22, tip member 20, and underground soil sample material to pass therethrough into sample tube(s) 6. Once the sample material passes therethrough, petal members 102 resiliently close and thereby prevent the sample material from falling out of sample tube(s) 6.
Tip retainer 14 used in apparatus 2 is identical to sample holder 16. Tip retainer 14 is positioned inside the male end of adapter 4. The lip 100 of tip retainer 14 is positioned between the male end of adapter 2 and the female end of sample tube 6. As sample tubes 6 are filled with sample material, tip locking member 22 and tip member 20 are forced through tip retainer 14. The petal members of tip retainer 14 flex open to allow tip locking member 22 and tip member 20 to pass into the interior of adapter 4. After tip member 20 passes into adapter 4, the petals of tip retainer 14 resiliently close to prevent tip locking member 22 and tip member 20 from falling back into sample tubes 6.
As is apparent, the outside diameters of all portions of tip locking member 22 and tip member 20 are sufficiently small to allow tip locking member 22 and tip member 20 to pass through passageway 12 from tip holder 8 to adapter 4. Tip locking member 22 and tip member 20 are prevented from falling out of the cutting end of apparatus 2 by the abutment of tip locking member shoulder 80 with tip holder shoulder 52.
If the penetrometer tubing string does not have an internal diameter large enough for receiving tip locking member 22 and tip member 20, sufficient bore space is preferably provided in the male end of adapter 4 for receiving tip locking member 22 and tip member 20 after tip locking member 22 and tip member 20 pass completely through tip retainer 14. Alternatively, an additional sample tube 6 can be added to the sample tube string and used for holding members 20 and 22. The additional sample tube 6 is positioned adjacent adapter 4. With the additional sample tube 6 thus positioned in apparatus 2, tip retainer 14 is simply positioned in the male end of the additional sample tube 6 rather than in the male end of adapter 4.
In the method of the present invention, apparatus 2 is first assembled as shown in FIGS. 1-3. In order to prevent tip locking member 22 and tip member 20 from moving downward in tip holder 8 when, prior to insertion, the assembled apparatus 2 is suspended above the ground, tape can be applied to tip member 20 and cutting member 10. Any tape applied to the exterior of apparatus 2 will be quickly removed from apparatus 2 by abrasion as apparatus 2 is driven into the ground. Alternatively, when apparatus 2 is suspended above the ground, tip locking member 22 and tip member 20 can be held in the position shown in FIG. 1 by hand. If tip locking member 22 is allowed to drop within tip holder 8 when apparatus 2 is suspended above the ground, locking keys 18 will be forced into recess 85 by frusto-conical interior surface 48. Consequently, tip locking member 22 will be "unlocked" such that tip locking member 22 and tip member 20 will not remain in the driving end portion of apparatus 2 as apparatus 2 is being driven into the ground.
Following assembly, apparatus 2 is driven into the ground to a desired subterranean location. Apparatus 2, and the cone penetrometer string to which apparatus 2 is attached, are preferably driven into the ground using a hydraulic ram.
As apparatus 2 is run into the ground, the ground resistance encountered by tip member 20 urges tip member 20 and tip locking member 22 toward the adapter end of apparatus 2. However, as discussed above, locking keys 18 positioned between rim 88 and annular lip 38 prevent tip locking member 22 from leaving tip holder 8. Consequently, tip member 20 is held substantially in the position shown in FIG. 1 as apparatus 2 is driven into the ground.
The ground resistance encountered by tip locking member 20 as apparatus 2 is driven into the ground also urges tip member 20 more tightly against tip locking member 22. The resulting compressive force substantially flattens O-ring 94 and thereby forces O-ring 94 snugly against the internal surface of cylindrical interior bore portion 50 of tip holder 8 so that O-ring 94 effectively seals passageway 12. Consequently, soil and/or water from other formations are prevented from entering sample tube(s) 6 as apparatus 2 is driven into the ground.
When apparatus 2 reaches a desired underground location, the driving operation is discontinued and the penetrometer tubing string is pulled a slight distance in the direction opposite to the direction in which said tubing string was driven into the ground. As is apparent, pulling the tubing string in the manner just described also moves the housing of apparatus 2 in the direction opposite to the direction in which apparatus 2 was driven into the ground. However, during this pulling operation, subterranean material which has compacted around tip member 20 as a result of the driving operation will hold tip member 20 and tip locking member 22 in fixed position in the underground formation until shoulder 52 of tip holder 8 abuts shoulder 80 of tip locking member 22.
During the pulling operation, as shoulder 52 of tip holder 8 approaches shoulder 80 of tip locking member 22, frusto-conical interior surface 48 of tip holder 8 contacts the outer ends of locking keys 18 and pushes the locking keys into recess 85. Consequently, this pulling operation unlocks tip locking member 22 so that tip locking member 22 and tip member 20 are thereafter allowed to move out of tip holder 8 toward adapter 4.
After the penetrometer tubing string has been pulled a sufficient distance to unlock tip locking member 22, the tubing string is driven further into the ground in order to fill sample tube(s) 6 with underground sample material. As the penetrometer tubing string drives the housing of apparatus 2 further into the ground, tip locking member 22, and tip member 20, which are now unlocked, remain in fixed position in the underground formation. Consequently, as the housing of apparatus 2 is driven deeper into the ground, tip locking member 22 and tip member 20 travel through sample holder 16, through sample tube(s) 6, through tip retainer 14, and into adapter 4. After tip locking member 22 and tip member 20 pass through tip retainer 14, the petal members of tip retainer 14 will resiliently close to prevent tip locking member 22 and tip member 20 from falling back into sample tube(s) 6 and thereby interfering with the sample collected in apparatus 2.
As apparatus 2 is driven deeper into the ground and tip member 20 is forced within passageway 12 toward adapter 4, circular cutting edge 64 cuts a sample material core from the underground formation. The sample material core travels through sample holder 16 and is received in sample tube(s) 6.
After the sample tubes 6 have been filled with sample material, apparatus 2 is pulled from the ground. As apparatus 2 is pulled from the ground, the petal members of sample holder 16 resiliently close in order to prevent unconsolidated sample material from falling out of sample tube(s) 6.
After apparatus 2 is removed from the ground, apparatus 2 is disassembled such that the subterranean sample core can be pushed out of sample tube(s) 6.
A second embodiment of the inventive apparatus 110 is depicted in FIG. 6. Apparatus 110 is particularly desirable for use when samples must be taken from unconsolidated, watery and/or mushy underground formations. The material in such formations may be too fluid to force tip locking member 22 and tip member 20 through sample tubes 6 and past tip retainer 14. If the formation material does not possess sufficient strength to force tip locking member 22 and tip member 20 through passageway 12, an adequate amount of the material cannot be collected in apparatus 2.
Apparatus 110 includes essentially all of the features of apparatus 2. However, apparatus 2 also includes a tube member 112, a rod member 114, and a cable connection 116. Further, in forming apparatus 110, the bolt 92 of apparatus 2 is replaced with a rod member 118 having external threads at one end thereof, for connecting rod member 118 to tip member 20, and a head portion 120 at the other end thereof.
As shown in FIG. 6, tube member 112 is positionable in apparatus 2 such that the lower portion of tube member 112 extends between locking keys 18 and into recess 85. The outside diameter of tube member 112 is preferably such that, when tube member 112 is positioned as shown in FIG. 6, tube member 112 will prevent locking keys 18 from falling into recess 85. Consequently, tube member 112 will prevent tip locking member 22 from unlocking when the apparatus 2 is suspended above the ground. Tube member 112 thereby eliminates the need to apply tape to tip member 20 and cutting member 10.
Tube member 112 has an inwardly extending lip 122 at the end thereof closest to tip locking member 22. Lip 122 has an inside diameter which is less than the outside diameter of the base of head portion 120 of rod member 118.
Rod member 114 is attached, by welding or by other means, to the end of tube member 112 furthest from tip locking member 22. If the apparatus 110 includes a tip retainer 14 as shown in FIG. 6, rod member 14 must be of sufficient length to extend through tip retainer 14 when shoulder 52 of tip holder 8 is abutting shoulder 80 of tip locking member 22 and tube member 112 is resting against the frusto-conical portion 86 of recess 85. Otherwise, a cable which is run down the penetrometer tubing string for connecting with cable connection 116 could be prevented by tip retainer 14 from reaching cable connection 116.
Cable connection 116 is preferably a commercial male air fitting (e.g., a Milton Kwik-Change Style A coupler) which is screwed onto, or otherwise attached to, the end of rod member 114. After apparatus 110 is driven into the ground to a desired location, a female air connection (not shown) connected to the end of a cable is lowered, or otherwise run into, the penetrometer tubing string toward apparatus 110. As will be understood by those skilled in the art, the internal spring member of the female air connection should be removed prior to inserting the female connection into the penetrometer string so that, when the female connection reaches the male connection, the internal ball members of the female connection will automatically move into the groove portion of male connection 116. Additionally, the groove portion of male connection 116 is preferably ground down sufficiently on one side so that the female connection can be removed from male connection 116 by jerking the cable.
Once assembled, apparatus 110 is driven into the ground in the same manner as apparatus 2. However, when apparatus 110 reaches a desired location in the formation, a female connection attached to the end of a cable is run into the penetrometer tubing string until said female connection reaches and connects with male connection 116. The cable is then used to pull tube member 112 away from tip locking member 22 a sufficient distance to allow locking keys 18 to fall into recess 85. With tube member 112 thus positioned, tube locking member 22 of apparatus 110 is unlocked in the same manner as described above for tube locking member 22 of apparatus 2.
After tip locking member 22 is unlocked, tube member 112 is pulled still further from tip locking member 22 until lip 122 of tube member 112 contacts the base of head portion 120 of rod member 118. The cable is then used to pull tip locking member 22 and tip member 20 through passageway 12 and into adapter 4, thus ensuring that tip locking member 22 and tip member 20 are retained by retainer 14. With the tip locking member 22 and tip member 20 thus retained at the adapter end of apparatus 110, said tip locking member and said tip member cannot interfere with the collection and retention of sample material in sample tube(s) 6.
When tip locking member 22 and tip member 20 are secured behind tip retainer 14, the female cable connection is removed from male connection 116 by jerking said cable. The female connection and cable are then pulled out of the cone penetrometer tube string.
Thus, the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned above as well as those inherent therein. While numerous changes may be made by those skilled in the art, such changes are encompassed within the scope of the invention as defined by the appended claims.
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The present invention provides an apparatus and method for obtaining a subterranean material sample. The inventive sampling apparatus comprises an elongate housing having a passageway extending longitudinally therethrough, a tip member movable through the passageway, and a locking means for releasably preventing the tip member from moving from a first portion of the passageway to a second portion of the passageway. The inventive sampling method comprises the step of inserting the inventive sampling apparatus into the ground. The present invention also provides a device for retaining material in a housing, said device comprising a plurality of resilient petal members.
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FIELD OF THE INVENTION
The present invention relates to the field of underground boring, and particularly to horizontal boring for placement of utility lines and the like.
BACKGROUND OF THE INVENTION
Impact-operated boring tools are well-known in the art. U.S. Pat. No. 3,756,328 issued to Sudnishnikov et al. discloses one such device. Impact-operated boring tools are used for burrowing holes in soil, particularly horizontal or near horizontal passages for installation of utility lines when trenching is undesirable. As the name implies, such boring tools function by impact. The tools possess a striking member (striker) slidable within a cylindrical housing. The striker delivers impacts on a surface at the front end of the housing. This impacting motion within the tool itself causes the soil around the tool to compact away from the nose of the housing, thus forming a hole.
The movement of the striker against the front surface is accomplished through the supply of pressurized fluid (such as compressed air) to a chamber behind the striker. Reciprocal movement is accomplished through the use of a control sleeve and ports in the striker. When the striker reaches a particular point in its forward path, the ports move past the sleeve to define an opening between the chamber behind the striker and the chamber in front of the striker. This allows the compressed air to pass to the chamber along the sides and in front of the striker. Because the cross-sectional area of the chamber in front of the striker is larger than the chamber behind the striker, the compressed air in the front chamber then forces the striker backwards. As the striker moves backwards, the opening defined by the ports is closed. When the striker reaches a particular point in its rearward path, the ports in the striker again move past the control sleeve to define an opening between the front chamber and exhaust passages leading to the atmosphere. The compressed air from the front of the striker is thus exhausted to the atmosphere. At this point, the pressure inside the chamber behind the striker again becomes greater than the pressure in front of the striker. Consequently, the striker begins to move forward once more.
Reversible impact-operated boring tools are also well-known in the art. U.S. Pat. No. 4,683,960 issued to Kostylev et al. discloses such a device. A reversing mechanism is often necessary to retrieve the tool from the hole being burrowed in case the tool encounters an obstruction in the soil or deviates greatly from a straight path.
Over the years, numerous attempts have been made to improve the safety and reliability of the reversing mechanisms. Trying to simplify the means for switching from the forward to the reverse mode of operation often resulted in uncertainty about which direction the machine was traveling in the hole. It seemed that the simpler it was to switch modes, the easier it was to switch accidently. Apart from the obvious danger this posed to the operators of the tool, this could also be very time consuming. If an operator were to switch modes accidently, time thought to be spent on burrowing may actually be time spent on retrieving the tool unwittingly. The error would not be discovered immediately, thereby wasting valuable operation time.
The prior art discloses various means for accomplishing reverse motion. Some require interrupting the pressurized fluid supply. Others require manipulation of the hose supplying the pressurized fluid to the tool, either by rotating the hose or by pulling it back. Still others require both the interruption of the pressurized fluid supply and the manipulation of the hose. However, each means has its disadvantages.
U.S. Pat. No. 4,662,457 to Edward J. Bouplon discloses a reversing mechanism requiring both means. The pressurized fluid supply must be terminated and then the hose must be rotated approximately one quarter turn clockwise in order to switch to the reverse mode of operation. Sometimes, when the pressurized fluid supply is terminated and the tool is therefore shut off, the tool does not restart when the pressurized fluid supply is recommenced. U.S. Pat. No. 4,840,237 to Helmuth Roemer discloses a reverse mechanism requiring that the hose be rotated. When the hose is flexible, it is often difficult to relate the degree of rotational motion of the hose at the surface to the degree of rotational motion at the tool itself, which may be some distance away. Consequently, it is often difficult to reverse the operation of the tool, or to be certain of the direction of operation.
U.S. Pat. No. 4,683,960 to Kostylev et al. discloses a reversing mechanism that requires applying sufficient force to a steel cable surrounding the air supply hose to overcome the compression force of a spring within the cable. Compression of the spring enables reverse operation of the tool. An alternate embodiment of the invention depicts a flanged tube within the air supply hose for accomplishing the same result as the steel cable--compression of the spring. There is no way of knowing whether the tension force is sufficient to overcome the compression force of the spring, which may be some distance away, in order to reverse the direction of operation. Consequently, the uncertainty concerning which direction the tool is operating remains.
U.S. Pat. No. 4,214,638 to Sudnishnikov et al. is an earlier patent which discloses a reversing mechanism that does not require manipulation of the fluid supply hose. The invention employs a control valve for alternately supplying compressed air or suction to the boring tool. When suction is applied, a control element within the tool is displaced. The tool operates in the reverse mode when compressed air is then resupplied. To switch back to the forward mode, suction is re-applied. This causes the control element to be displaced back to the position for forward movement. While no hose manipulation is required in the above invention, the exact same procedure is employed for switching from forward to reverse mode. Consequently, uncertainty regarding which direction the tool is operating remains.
U.S. Pat. No. 4,250,972 issued to Paul Schmidt on Feb. 17, 1981 discloses a patent employing a second compressed air supply. The patent claims to disclose a method for reversing operation of impact-operated boring tools that does not require any hose manipulation and which assures starting of the ram borer in any position along a borehole. Reverse motion is achieved when the second compressed air supply is initiated.
The impacting motion within the tool presents some problems associated with the service-life of the tool. Most tools contain a sleeve made of an elastomeric material within the tailpiece assembly to dampen some of the shocks emitted by the tool in operation. The sleeve is placed between the fluid inlet tubes and the tailpiece, and is usually glued to both. It is the gluing in this region which has presented the problems. The glue must be carefully chosen to be strong enough to withstand the shocking motion. However, the attachment becomes weakened as the glue ages and dirt gathers in the region of the gluing, thus the service-life of the tool is decreased.
Due to the uncertainty presented by the current means for reversing operation of impact-operated boring tools, and the increased labor and time often involved, an alternate means for reversing operation quickly and safely is needed. Due to the decrease in service-life associated with current shock dampening means in tailpiece assemblies, an alternate assembly is needed.
SUMMARY OF THE INVENTION
In one aspect, the invention relates to a reversible impact-operated boring tool. The tool disclosed employs a secondary fluid supply line which supplies pressurized fluid to a directional valve within the tool. When pressurized fluid is supplied to this directional valve, the tool operates in the forward mode to burrow holes in the soil. When pressurized fluid is exhausted from this directional valve, the tool operates in the reverse mode for retrieval. The primary pressurized fluid supply which enables reciprocal movement of the tool does not have to be terminated, nor does the supply hose have to be manipulated in any manner.
In another aspect, the invention relates to a distinct valving member comprising an inner spring and which is attached in such a manner permitting it to slide along both the outer and inner fluid inlet tubes while preventing the passage of pressurized fluid through the region of attachment. The sliding motion is accomplished using a secondary fluid supply by which pressurized fluid is supplied to the inner chamber of the directional valve. A spring surrounding the inner fluid inlet tube and contained within the directional valve helps to keep the directional valve in the position enabling forward motion of the tool. When the pressurized fluid is exhausted from the directional valve, the pressure exerted on the forward portion of the valve from the primary fluid supply is sufficient to compress the spring, thereby moving the directional valve to the position enabling the rearward motion of the tool.
In another aspect, the invention relates to a modification in the tailpiece assembly. The tailpiece assembly of the tool disclosed comprises a shock dampener glued to the exterior of the outer fluid inlet tube and to the interior of a steel canister. The steel canister is then press fit into the tailpiece. The press fitting of the canister eliminates some of the problems in service-life associated with gluing the shock dampener directly to the tailpiece such as aging and weakening of the glue, maintaining cleanliness of the assembly, and selection of inappropriate glue.
In another aspect, the invention relates to a method for rapidly alternating from the forward mode of operation to the reverse mode of operation, comprising a secondary fluid supply possessing a control valve. When the control valve is turned to a particular position, pressurized fluid is supplied to a directional valve, and the striker is directed against a surface in the front of the tool. This causes the tool to move forward. When the control valve is turned to another position, pressurized fluid is exhausted from the directional valve, and the impact of the striking member is now directed to a surface in the rear of the tool. This causes the tool to move rearward. The tool can be switched back to the forward mode by turning the control valve so that pressurized fluid is supplied to the directional valve once more.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following description, taken in conjunction with the accompany drawings, in which:
FIG. 1 is a longitudinal side view of the reversible impact-operated boring tool in the forward mode of operation;
FIG. 2 is a longitudinal sectional view of the reversible impact-operated boring tool illustrating the reversing mechanism in greater detail;
FIG. 3 is a longitudinal side view of the reversible impact-operated boring tool in the reverse mode of operation;
FIGS. 4 and 5 are sectional views depicting the directional valving member in the positions for forward (FIG. 4) and reverse operation (FIG. 5) of the tool.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The FIGURES illustrate a reversible impact-operated boring tool 10 forming a first embodiment of the present invention which includes a hollow outer housing 14 that consists of a torpedo-shaped body 12 and a coaxial tailpiece 40. An air driven piston-like striker 70 reciprocates lengthwise in the housing 14. If the striker 70 impacts at the right end of the housing 14 as seen in FIG. 1, the tool will be driven forward. Conversely, if the striker impacts at the left end of the housing as seen in FIG. 3, reverse motion results.
To control the motion of striker 70, a directional valving member 100 is provided which is slidably mounted on inner fluid inlet tube 60 and outer fluid inlet tube 58. The valving member 100 is slidable between a first, forward position on the tubes, as seen in FIG. 1, and a second, rearward position as seen in FIG. 3. A valving member chamber 102 is defined inside the valve member 100. A spring 104 inside valving member chamber 102 is in contact with the forward end of the valving member 100 and with outer fluid inlet tube 58 adjacent the rear end of the valving member 100. A slotted spring supporting ferrule 68 circumferentially surrounds the inner fluid inlet tube and comprises three slots which communicate the valve member chamber with the fluid supply.
The striker 70 defines jointly with the housing 14 a rear operating chamber 72 and a forward operating chamber 80. The striker 70 is essentially cylindrical in shape but has a frustroconical taper at the front to form a flat forward impact surface 71. The striker has ports 74 through the cylindrical shell of the striker which connect the forward chamber 80 alternately with the rear chamber 72 and then with the exhaust passages 49 during reciprocal movement.
There is an anvil 90 fixedly attached to the outer housing 14 which is circumferentially surrounded by the outer housing 14 at the tapered end of the housing and which projects beyond the outer housing 14 at the front of the tool. The anvil 90 contains a rearwardly facing impact surface 92 upon which the striker 70 impacts during forward motion of the tool. The front end projection 94 accommodates different boring heads for different soil compositions.
Both fluid inlet tubes 60 and 58 are connected to hoses supplying pressurized fluid through a hose nut 56 in the rearward region covered by the tailpiece 40. The inner fluid inlet tube 60 is threadedly attached to the hose nut 56. The outer fluid inlet tube is attached to the hose nut 56 by means of a flange 59 on the outer fluid inlet tube 58 in operative association with an annular notch 55 in the hose nut which together accommodate an "O" ring 57 to provide an "O" ring seal when the inner fluid inlet tube 60 is screwed into the hose nut. A secondary fluid supply hose with a diameter of 1/8 inch is in operative association with the secondary fluid inlet tube through the smaller passage 52 in the hose nut 56 which is threaded at the rearward end. A 1/8 inch hose coupling 38 threadedly attaches the secondary fluid supply hose to the hose nut. A primary fluid supply hose with a diameter of 1 inch is in operative association with the primary fluid inlet tube through the larger passage 54 in the hose nut 56 which is threaded at the rearward end. A 1 inch hose coupling 24 threadedly attaches the primary fluid supply hose to the hose nut.
The tailpiece functions to prevent dirt from entering the tool and to dampen the vibrations when the tool is in operation. The taper attachment portion of the tailpiece 42 press fits into the tailpiece 44. Together, these tailpiece portions cover the entire hose coupling region. A flanged portion of the outer fluid inlet tube 62 helps prevent the forward axial displacement of the tailpiece 44.
The tailpiece assembly 40 comprises a shock damper 48 made of elastomeric material for dampening the vibrations caused by the impacting motion within the tool. The shock damper 48 is fixedly attached to the exterior of the outer fluid inlet tube 58 and to the interior of a steel canister 47. The steel canister 47 is then press fit into the tailpiece 44. Axial exhaust passages 46 transverse the tailpiece 44. A flanged portion 45 on the tailpiece, in conjunction with the canister 47 and fixedly attached shock dampener 48, helps prevent the rearward axial displacement of the outer fluid inlet tube. The interior circular surface 49 of the tailpiece 44 facing towards the front of the tool serves as the forwardly facing impact surface when the tool is operated in the reverse mode.
The secondary fluid supply comprises a control valve 32 mounted in the line at a convenient position for control, preferably at the operator's station, for supplying pressurized fluid to or exhausting pressurized fluid from the directional valving member 100. The control valve contains ports 34 such that when the lever 33 on the control valve is positioned perpendicular to the secondary fluid supply hose 36 the pressurized fluid is exhausted from the directional valving member 100. When the lever 33 is positioned parallel to the secondary fluid supply hose 36, pressurized fluid passes into the directional valving member 100.
FORWARD OPERATION
To begin operation of the tool in the forward mode, the control valve is positioned to pressurize chamber 102. The pressurized fluid passes along the interior of the outer fluid inlet tube 58 and through the slots 68 in the supporting ferrule 66 into the valve member chamber 102. The pressurized fluid present in the valve member chamber 102 and the spring 104 within the directional valving member 100 maintain the precompression position as indicated in FIG. 1. The directional valving member 100 is prevented from sliding further forward by a retaining ring 64 circumferentially surrounding the inner fluid inlet tube 60. "O" ring seals 106 and 107 between the directional valving member 100 and the outer and inner fluid inlet tubes 58 and 60 permit the sliding motion of the directional valving member 100 over the tubes while preventing the leaking of pressurized fluid from within the valve member chamber 102.
The primary fluid supply is then initiated and pressurized fluid is fed by the primary fluid supply line 22 through the interior of the inner fluid inlet tube 60 into the rear operating chamber 72. The presence of pressurized fluid in the valve member chamber 102 and the force of the spring 104 prevents the pressure exerted by the pressurized fluid in the rear operating chamber 72 on the directional valving member 100 from moving the member 100 from the forward position. The force of pressurized fluid in the rear operating chamber 72 pushes the striker 70 forward to impact against the rearwardly facing impact surface 92 of the anvil 90, i.e., the front or forward impact surface. The ports 74 overlie the outer surface of member 100 to prevent air flow from chamber 72 to chamber 80. As the striker 70 approaches the forwardmost position in it axial pathway, ports 74 in the striker move past the forward end of member 100 and begin to connect the rear operating chamber 72 with the forward operating chamber 80. As pressurized fluid begins accumulating in the forward chamber 80, the striker 70 is forced in a rearward direction due to the increased surface area of the exterior of the striker 70.
Because of the position of the directional valving member 100, the front operating chamber 80 connects with the axial exhaust passages 46 as the striker moves rearward well before the striker would hit surface 49. The pressurized fluid in the front operating chamber is thereby exhausted to the atmosphere. When this occurs, the high pressure inside the rear operating chamber 72 causes the striker 70 to being to travel forward once more. This reciprocal movement will continue as long as the primary fluid supply 20 continues to supply pressurized fluid to the rear operating chamber 72.
REVERSE OPERATION
To begin operation in the reverse mode, the lever 33 on the control valve 32 is positioned perpendicular to the secondary fluid supply hose 36. This simultaneously terminates the supply of pressurized fluid to the valve member chamber 102 and enables the exhaust of pressurized fluid present in the valve member chamber 102 to the atmosphere through ports 34 in the control valve 32. As the fluid is exhausted from the valve member chamber 102, the pressure exerted on the directional valving member 100 by the pressurized fluid in the rear operating chamber 72 causes the directional valving member 100 to slide rearward, thereby compressing the spring 104, and moving valving member 100 to the rearward position shown in FIG. 3. When the spring 104 is compressed, the directional valving member 100 extends past the cupped flange 63 of the outer fluid inlet tube 58. The cupped flange 101 of the directional valving member 100 is slid back to the wrench flat 61 on the inner air inlet tube 60.
The primary fluid supply 20 continually supplies pressurized fluid to the rear chamber 72. With the directional valving member 100 now in the position depicted in FIG. 3, the forward path of the striker 70 is shortened, and the rearward path is lengthened. During forward movement of the striker 70, the ports 74 in the striker 70 connect the rear operating chamber 72 with the forward operating chamber 80 sooner than when the tool is operating in the forward mode. The striker 70 thus begins traveling rearward before impacting on the rearwardly facing front impact surface 92. During the rearward movement of the striker 70, the ports 74 in the striker 70 connect the forward chamber 80 with the atmosphere through the axial exhaust passages 46 much later (i.e., the striker must be closer to the tailpiece than when this occurs in the forward mode). As shown in FIG. 3, the ports 74 in the striker 70 don't connect the forward chamber 80 with the axial exhaust passages 46 until the rear impact surface 78 of the striker 70 virtually abuts against the forwardly facing rear impact surface 49 of the tailpiece 40. Impact against the rear of the tool is thereby achieved. As with the forward operation, the striker 70 will continue to reciprocate against the rearwardly facing impact surface 49 as long as the primary fluid supply 20 continues to supply pressurized fluid to the rear operating chamber 72.
To switch back to the forward mode, the lever 33 on the control valve 32 is once again positioned parallel to the secondary fluid supply hose 36. As pressurized fluid begins to pass into the valve member chamber 102, the pressure exerted within the valve member and spring 104 cause the directional valving member 100 to slide forward to the position shown in FIG. 1, abutting the retaining ring 64. The retaining ring 64 around the inner air inlet tube 60 prevents the directional valving member 100 from sliding any further along the inner fluid inlet tube 60. With the directional valve in the position shown in FIG. 1, the striker 70 once again impacts against the rearwardly facing front impact surface 92 of the anvil 90 during forward axial movement.
It will be understood that the above description is of a preferred exemplary embodiment of the invention and is meant to be illustrative, not limitative. Modifications may be made in the structural features of the invention without departing from the scope of the invention as expressed in the appended claims.
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A reversible impact-operated boring tool and a method for reversing the direction of operation of the same rapidly and safely is disclosed. The tool according to the invention possesses a second supply line for supplying pressurized fluid to the tool. The second supply line provides pressurized fluid to a directional valve within the tool. The tool operates in the forward mode for borrowing into the soil when pressurized fluid is supplied to this directional valve. When the pressurized fluid supply is terminated and the fluid is exhausted from the valve, the tool operates in the reverse mode. The tool according to the invention can be reversed safely without any need for hose manipulation and without turning off the primary fluid supply line.
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FIELD OF THE INVENTION
[0001] The present invention is directed to a bladder catheter for transurethral introduction into the urinary bladder through the urethra, composed of a flexible catheter shaft having a refillable balloon element secured thereto, which communicates with a filling channel integrated in the wall of the catheter shaft.
BACKGROUND
[0002] When providing health care, the use of bladder catheters is often required. Bladder catheters in use today are composed of a flexible catheter shaft, to whose distal end, which is placed in the urinary bladder, a fluid-refillable ballon element is fastened. The catheter shaft has a filling channel, which leads into the balloon interior via an opening in the catheter wall. The main purpose of the balloon element is to securely mechanically anchor the catheter in the urinary bladder. In addition, when placed in the opening of the bladder, the balloon has a certain sealing function and prevents urine from flowing out of the bladder, past the catheter and through the urethra.
[0003] In the unfilled state, the balloon element resembles a sleeve pulled over the catheter shaft, fitting on the shaft all-around, typically under slight tensioning, in any case, however, in a fold-free manner. The sleeve is comparable to a hose fitting, and is usually fabricated from the same material or a substantially identical material as the shaft, but is modified in its elongation properties. Conventional balloon elements are designed with this specific type of construction, which, in the emptied state, fits closely on the shaft, to enable the balloon element to be advanced with as little as possible resistance, through the urethra into the bladder lumen. In this way, painful irritations or lesions of the urethra's mucous membrane, caused by folds or bulges in the wall of the balloon element that previously existed or formed during the advancing motion, are avoided when inserting the catheter. Once the balloon element is securely introduced into the bladder, the sleeve (balloon element) closely fitting on the shaft, is elastically expanded into a balloon by a fluid, under relatively high pressure. The material typically selected for the catheter shaft and the balloon element of conventional catheters, latex or silicon, permits an elastic expansion of the balloon element to a volume of 5 and 30 ml, respectively. These are the two standard balloon volumes for bladder catheters used in clinical practice.
[0004] Ideally, the balloon element, that has been elastically expanded into a balloon, fully retracts, even after a longer-term use of the catheter, and closely fits on the catheter shaft as a sleeve-type hose fitting, without forming folds or bulges. In this way, the drained balloon element does not cause any painful irritation or trauma to the sensitive urethra epithelium even during removal of the catheter. Typically, however, the balloon element, that has been elastically expanded for an extended period of time into a balloon, is not able to be fully elastically retracted onto the shaft. The partial loss of the sleeve elasticity caused by an elastic expansion of the balloon element over several days can be accelerated by the action of chemically aggressive urinary components (e.g., uric acid). In the case of latex-based catheters, given a long-period use, the urine regularly leads to a pronounced stiffening of the balloon element, but also to a considerable loss of elasticity of the catheter shaft. Once drained, balloon elements of the known type of construction, having a latex- or silicon-based sleeve, often exhibit residual, coarse folds or bulges in the (not fully) retracting envelope, and pose a considerable risk of injury to the patient.
[0005] Moreover, catheter materials customarily used up to now (latex, silicon, or latex- or silicon-based materials, and/or composite materials made of latex and silicon) have other clinically relevant disadvantages.
[0006] One drawback (particularly when latex materials are used) is that the balloon element does not always open out symmetrically with respect to form when elastically expanding and can burst in response to slight lateral weighting. The stability of the balloon anchoring in the opening of the bladder can be adversely affected by a pronounced asymmetry of the balloon with respect to form. Moreover, a pronounced asymmetry of the filled balloon element, depending on its placement in the opening of the bladder, can cause the catheter lumen to snap off.
[0007] A final disadvantage is that the balloon element of catheters of a conventional type of construction, as necessitated by the particularities of the manufacturing and the material, must remain below specific wall thicknesses. The minimum wall thickness of the elastically expanding sleeve, when filled to form the balloon, must be such that it is able to avoid, with certainty, falling below a lower, critical minimum wall thickness, below which the danger of rupture exists, in response to increasing shaping-out of the balloon (and the reduction in the balloon wall thickness accompanying the elastic expansion). The minimum wall thickness of the balloon element that fits on the shaft in the manner of a sleeve is typically within the range of at least 100 micrometers and requires relatively high pressures when the sleeve undergoes elastic expansion or deformation. During expansion, the balloon element assumes a shape predominantly in the radial, but also in the longitudinal direction (elongation). With increasing filling volume, the pressures forming in response to the predominantly radial elastic expansion of the balloon envelope in many cases cause a compression or stenosis of the drainage lumen of the catheter. This lumen-narrowing effect is furthered by the likewise occurring elastic expansion of the balloon in the longitudinal direction and, as a consequence thereof, the the elongation of the catheter shaft in the balloon region. Both elongation components can lead to a considerable narrowing or stenosis of the catheter lumen.
[0008] It is a complex process to manufacture conventional bladder catheters, and one that requires many individual steps. In many cases, the particular dipping or molding processes do not ensure a satisfactory surface quality of the catheter and balloon. Above all, the silicon processing yields slightly rough and irregular boundary surfaces. This promotes the incrustation of urinary components, as well as the bacterial colonization of catheter surfaces.
[0009] The particular difficulty also arises when silicon is used, of water substantially permeating through the balloon envelope. To ensure that the balloon is adequately filled, it must typically be refilled in an almost daily cycle.
SUMMARY OF THE INVENTION
[0010] The object of the present invention is to avoid the above-mentioned disadvantages associated with the catheters of known methods heretofore and to devise a bladder catheter which will be able to be simply manufactured from a standpoint of production engineering and, above all, which will benefit the patient over long-term catheter use.
[0011] The objective is achieved in accordance with the present invention for a bladder catheter of the type mentioned at the outset in that the balloon element and the catheter shaft are made of a polyurethane, a polyurethane-polyvinyl chloride blend, or of a comparable, polyurethane-based material. It is, in fact, already known to manufacture a polyurethane shaft using the extrusion method for bladder catheters, and the method has been tried and tested in clinical applications on patients. However, due to its inadequate elongation properties, polyurethane was considered unsuitable for balloon elements of conventional design types.
[0012] For that reason, catheters having a polyurethane shaft were provided in known methods heretofore with balloon elements of latex or silicon or of related, similarly volume-expandable materials. A polyurethane sleeve that is pulled over the shaft (typical shaft diameter of approximately 4 to 6 mm for adults) and fits closely thereon, could only be elastically expanded to a balloon of a sufficient size (filling volume 5 or 30 ml) under very high pressure, which was only be able to be conditionally produced by the user using conventional means. The stresses produced in the wall of the balloon being shaped out would be considerable in any case. The drainage lumen of the catheter would be substantially constricted by the immense balloon filling pressure, as previously described.
[0013] Surprisingly, it turns out, however, that a polyurethane balloon element may nevertheless be used when manufacturing a bladder catheter, particularly when the balloon element is preformed into a balloon, as a balloon film having a wall thickness of 5 to 20 micrometers, preferably 5 to 15 micrometers. The preferably partially preformed base-state balloon in accordance with the present invention fits closely on the shaft wall in the empteied state, its envelope being folded. The preformed base-state balloon is provided in a generally known manner with two shaft pieces via which it is fastened to the catheter shaft. There is no need in accordance with the present invention to reduce the shaft diameter which allows for the base-state balloon that sits or lays folded on the shaft. The user may select the shaft thickness of the catheter in the usual manner and without any restrictions.
[0014] To conform to the catheter types in use today, the present invention proposes two basic, partially preformed, so-called base-state balloon types, which, in the completely filled, fully formed state (working balloon) have a filling volume of 5 ml or 30 ml.
[0015] To be able to achieve a working filling volume of 5 ml using filling pressure values that do not compromise the catheter shaft, the base-state balloon is designed in such a way that, in the unexpanded at-rest or base state, i.e., when the balloon is filled to the freely unfolded at-rest or base-state form (preferably spherical or spindle form), it has an at-rest or base-state volume of approximately 1.2 to 2.5 ml. In this filled base state, the cuff envelope is still unexpanded.
[0016] The balloon is preferably fastened to the shaft in the longitudinally extended form. In the process, the shaft pieces of the balloon are fixed to the shaft in such a way that they are maximally spaced apart, while avoiding a tensile stretching of the balloon envelope. The balloon envelope orients itself in a shaft-parallel lengthwise fold formation, and clings closely to the catheter shaft. The remaining at-rest filling volume in the balloon fastened in this manner, is typically less than 0.05 ml, preferably within the range of only 0.01 to 0.03 ml.
[0017] In the case of the specific embodiment of the 5 ml working filling volume, the wall thickness of the balloon envelope is preferably within the range of from 5 to 10 micrometers.
[0018] Given a larger working filling volume of, for example, 30 ml, in the unexpanded base state, i.e., when filling the balloon to the freely unfolded at-rest form (preferably cylindrical or spherical form), the base-state balloon receives a volume at rest of approximately 4 to 10 ml. The balloon is preferably fastened to the shaft in the longitudinally extended form (in the manner corresponding to the 5 ml balloon). The at-rest volume of the cuff applied in this manner is typically less than 0.08 ml, preferably in the range from only 0.02 to 0.04 ml. In the case of the specific embodiment of the 30 ml working filling volume, the wall thickness of the balloon envelope is preferably within the range of from 5 to 15 micrometers.
[0019] The polyurethane polymer used, the uninflated volume of the base-state balloon, and the wall thickness of the balloon are selected in such a way that the safety range of volumetric expandability of the balloon is preferably 300 to 400 percent and does not exceed a safety range of from 400 to 450 percent.
[0020] The balloon envelope that forms longitudinal or also unaligned folds allows a partially preformed base-state balloon to be elastically expanded to the filled working balloon in that comfortable pressure values are applied which do not constrict the catheter lumen. In the case of the preformed balloon according to the present invention, the filling pressure is typically only 50-200 mbar (given 5 ml working volume) and 50-250 mbar (given 30 ml working volume), respectively.
[0021] For the balloon according to the present invention, Pellethane 2363 materials having a Shore hardness of 70 to 90 along with their respective subforms (A,AE) are preferably used. Materials of other manufacturers having comparable technical material data may be used correspondingly.
[0022] The balloon, together with its shaft pieces, is bonded or fused to the catheter shaft. In the manufacturing of the base-state balloon, the transition regions from the shaft pieces to the central, mid-position diameter of the base-state balloon are designed to have wall thicknesses which continuously decrease from the shaft piece to the central, mid-position diameter.
[0023] It is advantageous when, after joining the balloon to the catheter shaft, the end rims of the shaft pieces are smoothed, for example, by the action of heat or application of solvents, so that no sharp-edged transitions are present in the transition region from the shaft to the balloon.
[0024] In addition, when polyurethane is used for the catheter shaft, the wall thickness of the catheter shaft is advantageously smaller than in previous designs, enabling the catheter drainage lumen to be enlarged, given the same external diameter. Thus, given a favorable material selection, a shaft wall thickness of from 0.4 to 0.8 mm, preferably from 0.4 to 0.6 mm suffices. The catheter shaft nevertheless retains its rigidity or safety against buckling, as required for insertion into the urethra in patient applications. To further reduce the catheter wall thickness, the catheter shaft is preferably formed from two concentrically extruded tubes, the inner tube preferably being designed to be thinner and harder than the outer tube (co-extrusion). To achieve the same objective, a spiral reinforcement or a stabilizing mesh worked into the shaft are also conceivable.
[0025] Moreover, the surfaces of both the balloon preferably fabricated using the blow-molding method and, respectively, of the preferably extruded shaft are of highest quality when polyurethane is used. Incrustation by urinary components, as well as bacterial colonization are rendered difficult by the special surface evenness.
[0026] The catheter described in accordance with the present invention is simple to manufacture in terms of production engineering and eliminates the need for cost-intensive manufacturing steps in comparison to conventional catheter types, such as, above all, latex catheters manufactured using the dipping method.
[0027] The catheter shaft is preferably provided with a plurality of filling openings in the region covered by the balloon. These filling openings have a square, preferably rectangular shape. This substantially prevents the thin film of the balloon from being able to close this opening or these openings in the manner of a valve and thereby complicate the process of emptying the balloon.
[0028] The dimensional design of the base-state balloon is calculated, i.e., its wall thickness is selected in a way that allows the envelope to be elastically expanded up to the working volume, while avoiding a non-elastic overstretching, i.e., the elasticity of the ballon material is completely retained, even in the case of long-term catheter use. Therefore, once the balloon is completely drained, it clings closely to the catheter shaft, again in longitudinal folds, as it is withdrawn through the urethra, and it is non-traumatizing.
[0029] The so-called suprapubic bladder catheter, another embodiment and version of a bladder catheter that is common in practice, may likewise be optimized by combining a polyurethane shaft with a polyurethane-based balloon element in accordance with the present invention. When the suprapubic catheter system is used, a hollow needle element is inserted through the anterior abdominal wall directly into the urinary bladder, directly above the pubic bone. The needle element may be designed as a conventional hollow needle, as a guide needle that is laterally open across the entire length of the needle (the catheter is inserted laterally into the guide needle), or, for example, as a so-called spread-type needle (the hollow needle is composed of two halves which are separable from one another by spreading).
[0030] Preformed balloon elements, in the specific embodiment according to the present invention of the balloon element having a working volume of 5 ml in the wall-thickness range of preferably 5 to 10 micrometers, may be pushed through the application needle when a lubricating agent is used, without having to restrict the diameter of the catheter shaft. Thus, the patient may also benefit from the afore-mentioned advantages of a bladder catheter that is manufactured in its entirety from polyurethane, when the suprapubic version is used.
[0031] It is also vitally important to the patient, who is typically catheterized suprapubically for extended periods of time, that the drained balloon element be removable, to the greatest possible degree without causing trauma, through the puncture channel in the bladder and abdominal wall that has already healed or granulated following a relatively long catheter application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The present invention is explained in greater detail on the basis of exemplary embodiments illustrated in the drawings, whose figures show:
[0033] FIG. 1 a lateral, part-sectional view of the distal end of the catheter;
[0034] FIG. 2 a lateral view of the catheter prior to its insertion; and
[0035] FIG. 3 a lateral view of the catheter prior to its introduction into or withdrawal from the urethra.
DETAILED DESCRIPTION
[0036] FIG. 1 shows the distal end of a bladder catheter 1 in a part-sectional, lateral view. Balloon element 3 , which is shown in a sectional view both as base-state balloon 4 (volume at rest) and as inflated balloon 5 (working volume), is fastened to catheter shaft 2 . Balloon element 3 is made of a polyurethane-based material; in its form as base-state balloon 4 , it has a wall thickness of 5 to 20, preferably of 5-15 μm. It is provided with shaft pieces 6 and 7 , via which it is bonded to catheter shaft 2 . At its distal end, hollow catheter shaft 2 has opening 8 , via which urine can flow out of the urinary bladder. A filling channel 9 situated in the wall of catheter shaft 2 leads to opening or plurality of openings 10 in catheter shaft 2 , which is/are placed in the region of balloon element 3 .
[0037] Once catheter 2 is introduced into the urinary bladder through the urethra, a suitable fluid, directed through channel 9 and opening(s) 10 into balloon element 3 , fills balloon element 3 , i.e., elastically expands it as it is increasingly filled from the base-state volume to its working volume.
[0038] In its completely emptied state, balloon element 3 fits on the surface of shaft 2 , as shown in FIGS. 2 and 3 .
[0039] In FIG. 2 , balloon element 3 shapes itself into a fold formation 11 that runs in the longitudinal direction of catheter shaft 2 . Fold formation 11 substantially extends between the two shaft pieces 6 and 7 .
[0040] The fold formation permits a bulging of balloon element 3 , which leads to base-state balloon 4 shown in FIG. 1 . This bulging takes place without any appreciable pressure and may vary in magnitude depending on the material used. In the unexpanded, freely unfolded state, base-state balloon 4 contains a volume at rest which is clearly less than the filling volume contained in filled balloon 5 (working volume). To illustrate the present invention, base-state balloon 4 is sketched having a relatively large volume at rest in FIG. 1 . To reduce the overall space required by the fold formation to the greatest degree possible, base-state balloon is mounted on the shaft in the longitudinally oriented form. The shaft pieces of the balloon are spaced as far apart as possible, as shown in FIG. 2 , without thereby tensioning the balloon envelope.
[0041] The transition region from shaft pieces 6 and 7 to the central, mid-position section of balloon 3 is kept as a continuous, fluid transition, so that the wall thicknesses continuously decrease from the thickness at shaft pieces 6 and 7 to the thickness at the central, mid-position diameter of base-state balloon 4 . The end rims 12 and 13 of shaft pieces 6 and 7 are smoothed, so that there is no sharp-edged transition.
[0042] As indicated in the upper portion of FIG. 2 , catheter shaft 2 may be composed of two preferably co-extruded tubes 14 and 15 , which fit one inside the other.
[0043] The lower portion of FIG. 2 shows the option of providing catheter shaft 2 with a spiral reinforcement 16 of metal.
[0044] FIG. 3 shows one specific embodiment of balloon element 3 , where base-state balloon 4 is fastened to the shaft in such a way that it is not aligned in a fold formation, but folded randomly or unsystematically. Thus, the shaft pieces of the balloon are not maximally spaced apart, but to a lesser degree.
[0045] The fold formation may run in any way at all, thus, for example, also transversely or at right angles to the catheter axis. However, since the balloon wall is exceptionally thin, once the ballon is drained, it may cling very closely to the surface of catheter shaft 2 . In some instances, hanging sack-like folds 17 or 18 form at shaft pieces 6 or 7 when the catheter is inserted or removed. On the right side of FIG. 3, 17 denotes a hanging sack-like fold which forms during insertion of the catheter, and on the left side of the figure, 18 denotes a hanging sack-like fold which forms during removal of the catheter through the urethra. However, in the wall-thickness range named in accordance with the present invention, even such hanging sack-like folds have no disadvantageous effect during passage of the balloon element through the urethra.
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A bladder catheter for transurethral introduction into the urinary bladder by the urethrae, includes an elastic catheter shank with a fillable balloon element secured thereto and connected to a filling channel incorporated into the wall of the catheter shank. The balloon element and the catheter shank are made of polyurethane, a polyurethane-polyvinylchloride mixture or similar polyurethane-based material.
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[0001] The present invention relates generally to a manner by which to communicate packet data in a packet radio, or other, communication system that uses a packet retransmission scheme. More particularly, the present invention relates to apparatus, and an associated method, in which selectably to combine a data packet together with a selected number of retransmissions thereof, sent pursuant to the retransmission scheme, and thereafter decoding the data. Selection of how many times to retransmit the data packet and when to perform the decoding operations is made responsive to channel conditions of the channel upon which the data packet, and the retransmissions thereof, are communicated. Improved decoder performance is provided as channel conditions are used to select the amount of data redundancy to be introduced prior to performing the decoding operations.
BACKGROUND OF THE INVENTION
[0002] A communication system operates to communicate data between a sending station and a receiving station. The data is communicated upon a communication channel formed between the sending and receiving stations. If necessary, the data to be communicated by the sending station is first converted into a form to permit communication of the data upon the communication channel. The data communicated upon the communication channel is detected at the receiving station. And, subsequent to detection of the data at the receiving station, operations are performed upon the data to recover the informational content thereof.
[0003] Many different types of communication systems have been developed and implemented. In some communication systems, the data to be communicated by the sending station to the receiving station is communicated in the electrical form by way of wireline connections interconnecting the sending and receiving stations. And, in some communication systems, the data is communicated in electromagnetic form, by way of radio links formed between sending and receiving stations. And, some communication systems include communication paths between endpoints formed of the sending and receiving stations that include both wireline and radio link portions such that the data is communicated in electrical form along a portion of the communication path and in electromagnetic form along another portion of the communication path.
[0004] The communication system is referred to as being a radio communication system when radio links are used to communicate the data in electromagnetic form. In contrast to a conventional wireline communication system that requires electrical connections to be formed between the sending and receiving stations, a radio communication system is inherently mobile. That is to say, because radio links, rather than wireline connections, are used along at least a portion of the communication paths extending between the sending and receiving stations, the sending and receiving stations need not be positioned in fixed locations, connected to wirelines, to permit communications to be effectuated therebetween.
[0005] A cellular communication system is a type of radio communication system that has achieved wide levels of usage and has been installed throughout extensive portions of the world. Successive generations of cellular communication systems have been developed. Reference is commonly made to at least three generations of cellular communication systems. A so-called, first-generation, cellular communication system generally refers to a cellular communication system that utilizes an analog modulation technique. An AMPS (advanced mobile phone service) cellular communication system is exemplary of a first-generation, cellular communication system. A so-called, second-generation, cellular communication system typically refers to a cellular communication system that utilizes a digital, multiple-access communication scheme. A GSM (global system for mobile communications) cellular communication system and an IS-95 (interim standard—1995), CDMA (code-division, multiple-access) cellular communication system are each exemplary of a second generation cellular communication system.
[0006] Third-generation, cellular communication systems are presently under development. Third-generation, cellular communication systems refer generally to cellular communication systems intended to provide universal communication service, including effectuation of data services, voice services, and multi-media services. Proposals for third-generation, cellular communication systems generally provide for IP (Internet Protocol)-formatted data. And, subsequent-generation, cellular communication systems are also being proposed. Such subsequent-generation cellular communication systems are generally also packet-based communication systems.
[0007] In a packet-based, communication system, data that is to be communicated by a sending station to a receiving station is formatted into data packets. And, the data packets are communicated upon the communication channel, usually during discrete bursts, and delivered to a receiving station. The data packets are operated upon by the receiving station to recover the informational content thereof. The communication channel upon which the packet data is communicated typically exhibits fading characteristics such that values of the data contained in a packet, when delivered to the receiving station differs in some values with the corresponding values of the data when transmitted by the sending station.
[0008] Operations performed upon the data packets at the receiving station attempt to compensate for the distortion introduced upon the data during its transmission upon the communication channel. If the distortion cannot adequately be compensated for, the informational content thereof cannot be recovered.
[0009] Some packet communication systems utilize a packet retransmission scheme in which a data packet is retransmitted by the sending station if the data packet has not been affirmed to have been adequately communicated to the receiving station. ARQ and HARQ retransmission schemes are used in a feedback setup in which the receiving station generates an acknowledgment when the informational content of the data packet is recovered at the receiving station. If the informational content is not acceptably recovered, the acknowledgment is not returned to the sending station. And, in an HARQ system, a negative acknowledgment is also returned to the sending station when the informational content of a data packet cannot acceptably be recovered. Retransmission of the data packet is thereafter effectuated. Multiple retransmissions of the data packet, if necessary, can also be effectuated. By sending multiple transmissions of the data packet, the likelihood that the informational content thereof can be recovered is increased.
[0010] 1×EV-DO and 1×Ev-DV, cellular system standard specification proposals, related to the proposed cdma2000 system, provide for analogous such retransmission schemes. In such present proposals, packet data is communicated to a mobile station, and a mobile station selectably requests packet retransmission as well as indicating to a base station of such system of channel conditions on a forward link upon which the packet data is communicated. If an initial transmission of a data packet, when received at the mobile station, is in error, the mobile station returns an NAK (negative acknowledgment) to the base station. Additional retransmissions of the data packet occur until the data packet is received correctly or until a maximum number of retransmissions occur. The retransmissions sometimes involve incremental redundancy where subsequent packets contain new parity information, as well as repeat redundancy where the same information is retransmitted.
[0011] Such existing retransmission schemes, however, generally perform data combining operations and decoding operations at each successive retransmission of a data packet. This existing operation is computationally-intensive and power-consumptive.
[0012] An improved manner by which to communicate packet data pursuant to a retransmission scheme that is less computationally-intensive and power-consumptive would be advantageous.
[0013] It is in light of this background information related to packet communication systems that the significant improvements of the present invention have evolved.
SUMMARY OF THE INVENTION
[0014] The present invention, accordingly, advantageously provides apparatus, and an associated method, by which to facilitate communication of packet data in a packet radio, or other, communication system.
[0015] Through operation of an embodiment of the present invention, a manner is provided by which to combine a data packet together with a selected number of retransmissions thereof.
[0016] Thereafter, the data is decoded. Selection of the number of retransmissions of the data packet prior to performance of decoding operations thereon is made responsive to channel conditions of the channel upon which the data packet and the retransmissions thereof are communicated. When the communication channel conditions are poor, greater numbers of retransmissions of the data packet are performed and combined theretogether prior to performance of decoding operations thereon. And, when channel conditions are determined to be good, fewer numbers of retransmissions are sent prior to performance of decoding operations upon the combination of the originally-transmitted data packets together with the retransmissions thereof.
[0017] Instead of performing decoding operations subsequent to each retransmission of the data packet, a selected number of data packet retransmissions are caused to be sent to the receiving station, and, once received, decoding operations are then performed. Reduced power consumption required to perform the decoding operations results as decoding operations need not be performed subsequent to every retransmission of the data packet.
[0018] Operation of an embodiment of the present invention takes advantage of a general relationship between a packet error rate of values of a data packet, subsequent to performance of decoding operations thereon, and the number of retransmissions of the data packet. The packet error rate generally decreases as a function of increased numbers of retransmissions of the data packet. By combining an increased number of values of the data packet as a result of increased numbers of retransmissions thereof, the likelihood of a packet error is reduced. By selecting a number, N, of retransmissions prior to performing decoding operations, reduced numbers of decoding operations are performed while also providing a significant likelihood of adequate recovery of the informational content of a data packet.
[0019] In one implementation, the number, N, of retransmissions of a data packet is a fixed value, calculated in advance, either theoretically or based upon operational simulations. The data packet together with the selected number of retransmissions thereof are provided to a combiner that buffers, or otherwise combines, the values provided thereto. Operation of a decoder is inhibited until all N retransmissions of the data packet are received at the receiving station. Once the selected number of retransmissions are received, the decoder operates to decode the values received at the receiving station.
[0020] In another implementation, the number, N, of retransmissions is dynamically, or otherwise adaptively, determined. The number of retransmissions is determined, e.g., by measuring a channel quality indication and accumulating values thereof at successive retransmissions of the data packet. When the cumulative sum of the accumulated values equals, or exceeds, a threshold, the values are combined and provided to a decoder to decode the values provided thereto. In another implementation, the dynamic selection of the number N of retransmissions is made based upon instantaneous measurements, such as measurements made together with, or subsequent to, retransmission of the data packet. If the instantaneous measurement equals, or exceeds, a threshold value, the values of the data packet together with the selected number of retransmissions thereof already-transmitted to the receiving station or provided to a decoder to be decoded thereat.
[0021] In one implementation, a mobile station is operable in a packet radio communication system, such as a cellular communication system constructed to communicate 1×EV-DO communication system, to which packet data is communicated by a base station. The mobile station includes a channel quality estimator that generates forward-link channel communication conditions of the forward-link channel upon which the packet data is communicated to the mobile station. Channel quality estimates are provided to a controller. The controller controls operation of a packet buffer and combiner and a turbo decoder. The controller also controls generation of acknowledgment and negative acknowledgment (ACK/NAK) responses that are returned by the mobile station to the base station subsequent to detection at the mobile station of a data packet. Responsive to indications of the channel quality estimated by the estimator, the controller selectably causes negative acknowledgment messages to be returned to the base station, thereby precipitating retransmission of the data packet. The data packet, together with retransmissions thereof, are buffered and combined at the packet combiner. When the channel quality estimate generated by the estimator is of values, either instantaneously or cumulatively, at least as great as a selected threshold, the controller initiates generation of a positive acknowledgment (ACK) message to be returned to the base station. The controller also releases the values buffered and combined at the packet combiner and causes decoding operations to be performed by the decoder when the values of the data are provided thereto.
[0022] Because the decoder does not need to operate at each successive retransmission of the data packet, reduced computational complexity, as well as reduced levels of power consumption, are provided pursuant to operation of an embodiment of the present invention.
[0023] In these and other aspects, therefore, apparatus, and an associated method, are provided for a packet communication system. Packet data is communicated to a first communication station pursuant to an ARQ retransmission scheme upon a communication channel by a second communication station. Recovery of the values of a data packet communicated to the first communication station is facilitated. A data packet combiner is coupled to receive at least a selected data packet of the packet data together with a selected number of retransmissions of the selected data packet. The data packet combiner at least buffers the selected data packet and the selected number of retransmissions thereof. A decoder is coupled to the data packet combiner. The decoder is selectably operable to recover values of the selected data packet and the selected number of retransmissions thereof. The decoder selectably decodes the values provided thereto to form a decoded representation of the selected data packet. A controller is coupled to receive indications of channel conditions of the communication channel. The controller operates responsive to the indications of the channel conditions and selects the selected number of retransmissions buffered at the packet data combiner, together to be provided to the decoder.
[0024] A more complete appreciation of the present invention and the scope thereof can be obtained from the accompanying drawings which are briefly summarized below, the following detailed description of the presently-preferred embodiments of the invention, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 illustrates a functional block diagram of a packet radio communication system in 110 which an embodiment of the present invention is operable.
[0026] [0026]FIG. 2 illustrates a graphical representation of an exemplary relationship between the number of retransmissions of a data packet in a packet radio communication system that utilizes a packet retransmission scheme and the corresponding packet error rate of a decoded packet, decoded from a combination of the values of the data packet together with the retransmissions thereof.
[0027] [0027]FIG. 3 illustrates a functional representation of operation of a portion of an embodiment of the present invention.
[0028] [0028]FIG. 4 illustrates a method flow diagram that lists the method steps of the method of operation of the method of an embodiment of the present invention.
DETAILED DESCRIPTION
[0029] Referring first to FIG. 1, a communication system, shown generally at 10 , provides for the communication of packet data between communication stations. Here, the communication system forms a packet radio communication system, such as a third-generation, cellular communication system that operates to provide 1×EV-DO or 1×Ev-DV data services. While the following description shall describe operation of an embodiment of the present invention in which the packet communication system comprises a packet-based, cellular communication system, it should be understood that an embodiment of the present invention is analogously also operable in other types of packet-based communication systems.
[0030] Packet-formatted data is communicated between communication stations of the communication system during a communication session to effectuate a communication service. Here, the communication system is shown to include a mobile station 12 that operates to communicate packet-formatted data by way of a radio link 14 with a network part of the communication system to which a correspondent node 16 is connected. Data that is originated at the correspondent node, for instance, is communicated to the mobile station by way of a communication path formed through the network part of the communication system, and upon the radio link 14 . The correspondent node and the mobile stations form the endpoints of a communication session pursuant to which a communication service is effectuated.
[0031] The network part of the communication system includes a radio access network (RAN) 18 and a packet data network (PDN) 22 , such as the Internet backbone. The packet data network and the radio access network are connected together by way of a gateway (GWY) 24 . The radio access network, in the exemplary implementation, is formed of the network infrastructure of a CDMA 2000, cellular communication system that provides for 1×EV-DO and 1×Ev-DV data services in which packet-formatted data is communicated upon a forward link of the radio link 14 to the mobile station.
[0032] The mobile station forms a radio transceiver capable of both receiving data communicated thereto upon the forward link of the radio link as well as sending data upon a reverse link of the radio link. And, pursuant to a packet retransmission scheme, the mobile station operates to generate ACK and NAK messages upon the reverse link of the radio link to acknowledge successful delivery of a data packet or, alternately, to instruct the network part of the communication system to retransmit a data packet.
[0033] The mobile station is here shown to include a radio frequency (RF) part 32 that operates at radio frequencies upon data received at the mobile station and data to be transmitted to the mobile station. The RF part is coupled to a receive modem 34 and to a transmit modem 36 . The receive modem operates upon data received at the mobile station and down-converted in frequency during operation of the RF part. And, the transmit modem generates transmit data that is provided to the RF part 32 . The mobile station includes apparatus 42 of an embodiment of the present invention. The apparatus is coupled to the receive modem 34 by way of the line 44 and to the transmit modem by way of the line 46 .
[0034] The apparatus 42 includes a packet combiner 48 and a forward link channel quality estimator 52 . The packet combiner and the estimator are each coupled to the line 44 . When a data packet communicated upon the forward link to the mobile station is detected thereat and operated upon by the RF part and the receive modem, the data packet is provided to the packet combiner to be buffered thereat and selectably combined with other data packets buffered thereat. Namely, during operation of an embodiment of the present invention, a data packet together with a selected number of retransmissions thereof, are buffered and selectably combined at the packet combiner.
[0035] The forward link channel quality estimator 52 operates to estimate communication conditions upon the forward link channel upon which the packet data is communicated. The estimate is obtained responsive to indicia contained in, or derived from, the data packets received at the mobile station.
[0036] The apparatus further includes a turbo decoder 54 that is coupled to the packet combiner 48 . The decoder is selectably operable to decode the data buffered, and combined, at the packet combiner. Decoded output data is generated on the line 56 upon completion of decoding operations by the decoder.
[0037] The apparatus further includes a controller 58 . The controller is coupled to receive channel quality estimates formed by the estimator 52 . The controller selectably generates control signals for application, here represented by way of the lines 62 and 64 , to the packet combiner 48 and to the turbo decoder 54 , respectively. The controller further selectably generates the ACK and NAK messages to be returned on a reverse link channel to the network part of the communication system. Responsive to instantaneous, or cumulative, values of the estimate formed by the estimator, the controller causes generation of the ACK or NAK messages as well as causes operation of the packet combiner to release the data buffered and combined thereat to the decoder and also to cause decoding operations to be performed by the decoder.
[0038] [0038]FIG. 2 illustrates a graphical representation of a plot 72 of a packet error rate formed as a function of a number of retransmissions of a data packet pursuant to the data retransmission scheme by which the communication system in FIG. 1 is operable. The plot indicates that with increasing numbers of retransmissions, the packet error rate of decoded data decreases. The plot indicates that, probabilistically, a data packet can be correctly decoded on its first transmission to the mobile station. Here, N retransmissions corresponds to a point on the plot at which an acceptable chance of correctly decoding the packet occurs. The value of N is calculated in advance, theoretically, or by way of simulations of operation.
[0039] Operation of the controller takes into account the relationship defined by the plot 72 in the generation of the ACK and NAK messages as well as the control signals applied to the packet combiner and turbo controller.
[0040] [0040]FIG. 3 illustrates a functional representation of operation of the controller 58 that forms a portion of the apparatus 42 . Here, the controller causes generation of the signals on the lines 62 , 64 , and 46 responsive to accumulated values of the channel quality estimate formed by the estimator 52 (shown in FIG. 1). At each successive retransmission of the data packet, an indicia of the channel condition estimated by the estimator is provided by way of line 55 to a cumulator 74 that forms a functional portion of the controller. The cumulator accumulates values of the indicia of the estimates to form a cumulative total. Indications of the cumulative total are provided to a comparator 76 that compares the cumulative total with a threshold value, here indicated to be applied to the comparator by way of the line 78 . When the comparator indicates that the cumulative total is at least as great as the threshold value, an indication is generated on the line 82 . Responsive to such indication, NAK messages are no longer generated by the mobile station. Also, the data buffered and combined at the packet combiner is released to the turbo decoder and a decoded representation of the data packet is generated on the line 56 at which point, if the packet is decoded successfully, an ACK message is transmitted. Otherwise, an NAK is transmitted.
[0041] In another implementation, instantaneous values, rather than cumulative values, are provided to the comparator to be compared against a threshold value. The application of instantaneous values is represented by the line 84 , shown in dash, in the figure.
[0042] Because the decoder need not be operated subsequent to each retransmission of a data packet, improved power-performance of the mobile station is permitted.
[0043] [0043]FIG. 4 illustrates a method, shown generally at 92 , of the method of operation of an embodiment of the present invention. The method facilitates recovery at a first communication station of values of a data packet communicated thereto by a second communication station.
[0044] First, and as indicated by the block 94 , a selected data packet of the packet data transmitted to the first communication station is buffered. Then, and as indicated by the block 96 , a selected number of retransmissions of the selected data packet is selected to be transmitted to the first communication station. The selected number is selected responsive to indications of channel conditions of the communication channel.
[0045] Then, and as indicated by the block 102 , retransmissions of the selected data packet are further buffered. And, as indicated by the block 104 , the selected data packet is selectably decoded together with the selected number of retransmissions thereof.
[0046] When the number of retransmissions of the data packet is dynamically selected, changing communication conditions on the communication channel upon which the data packet is communicated can correspondingly be quickly changed to increase, or decrease, the number of packet data retransmissions to increase throughput, or increase redundancy as appropriate, to best effectuate communication of the packet data.
[0047] The previous descriptions are of preferred examples for implementing the invention, and the scope of the invention should not necessarily be limited by this description. The scope of the present invention is defined by the following claims:
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Apparatus, and an associated method, for a packet radio communication system that utilizes a packet retransmission scheme. A data packet, together with a selected number of retransmissions thereof are sent to a mobile station, or other receiving station. A channel condition estimator estimates channel conditions on the communication channel and, responsive to the channel condition estimates, selection is made of the number of packet data retransmissions that are to be effectuated prior to performing decoding operations to recover the informational content of the data packet.
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