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TECHNICAL FIELD
This invention relates to improvement to earthboring tools, especially to steel tooth bits that use hardfacing containing carbide particles to enhance wear resistance.
BACKGROUND ART
The earliest rolling cutter earth boring bits had teeth machined integrally from steel, conically shaped, earth disintegrating cutters. These bits, commonly known as “steel-tooth” or “mill-tooth” bits, are typically used for penetrating relatively soft geological formations of the earth. The strength and fracture-toughness of steel teeth permits the effective use of relatively long teeth, which enables the aggressive gouging and scraping action that is advantageous for rapid penetration of soft formations with low compressive strengths.
However, it is rare that geological formations consist entirely of soft material with low compressive strength. Often, there are streaks of hard, abrasive materials that a steel tooth bit should penetrate economically without damage to the bit. Although steel teeth possess good strength, abrasion resistance is inadequate to permit continued rapid penetration of hard or abrasive streaks.
Consequently, it has been common in the art since at least the early 1930s to provide a layer of wear resistant metallurgical material called “hardfacing” over those portions of the teeth exposed to the severest wear. The hardfacing typically consists of extremely hard particles, such as sintered, cast or macrocrystalline tungsten carbide dispersed in a steel, cobalt or nickel alloy binder or matrix. Such hardfacing materials are applied by heating with a torch a tube of the particles which welds to the surface to be hardfaced a homogeneous dispersion of hard particles in the matrix. After hardfacing, the cone is preferably heat treated, which typically includes carburizing and quenching from a high temperature to harden the cone. The particles are much harder than the matrix but more brittle. After hardening, the matrix has a hardness preferably in the range from 53 to 68 Rockwell C (RC). The mixture of hard particles with a softer but tougher steel matrix is a synergistic combination that produces a good hardfacing.
There have been a variety of different hardfacing materials and patterns, including special tooth configurations, to improve wear resistance or provide self sharpening. Generally, the hardfacing applied to the teeth of new bits is in a preapplication ratio range of 50 to 80 percent carbide particles, typically about 70 percent, in a metal matrix of iron, nickel, cobalt or their alloys. The thickness of the hardfacing deposit on new bits is usually about {fraction (1/16)} to ⅛ inch over the flanks, end portions and top of the crest of the tooth. Portions of the hardfacing may be somewhat thicker. The thicker portions are generally at the corners where the flanks intersect the crest. These thicker portions may be up to double that of other areas.
Worn bits have been retipped by adding a type of hardfacing to the teeth after they have been worn. Often a substantial part of the original hardfacing would be worn off along with a portion of the underlying steel teeth. The retipping hardfacing materials typically used are about 35-50% by weight of carbide particles with a fairly soft copper, bronze, brass or iron matrix. The soft matrix allows the retipper to shape the new tooth being formed. Depending on the extent of wear, the hardfacing may be quite thick, even greater than {fraction (3/16)} inch on top of the top of the underlying steel tooth. Retippers normally do not heat treat the retipped bit. Because of the softer matrix and the lack of heat treating the hardness of the matrix after application on a retipped tooth would normally be considerably less than a new bit tooth. While satisfactory for very soft drilling, such as water well drilling, the retipped hardfacing is not as wear resistant as the original equipment hardfacings described above, which contain a higher percentage of carbide particles and a harder matrix metal.
While hardfacing provides good wear resistance for a steel tooth bit, teeth are still susceptible to breakage. Breakage is generally thought to occur due to portions of the teeth being too brittle. Brittleness, particularly in smaller diameter drill bits, is at least partially caused by the underlying carburized layer. The standard manufacturing procedure is to carburize the steel cone after it is hardfaced to harden the surface for resisting erosion. The carburizing is performed in a furnace, using either a gas or a pack process. This process adds carbon throughout the hardfacing, and also increases the carbon content in a carburized layer near the surface of the steel, the layer having a depth of about 0.030 to 0.140 inch depending upon bit size and application. The carburizing process creates a carburized layer even below the hardfacing.
If the tooth crest is fairly sharp as in smaller cones, the carburized layer becomes deeper at the crest of the tooth because the carburized layers on the two flanks and sharp crest tend to merge. This makes the crest brittle. Even though subsequently carburized, this brittle area can be subject to premature tooth failure.
DISCLOSURE OF INVENTION
In this invention, the underlying steel tooth or stub is formed with a shorter length than conventional. The flanks of the tooth stub will be sufficiently far from each other at the crest or top of the tooth stub to prevent the carburized layers on the flanks and crest from merging. Therefore there is no increase in carburized layer depth at the crest, unlike the prior art teeth with sharp crests. The distance from one flank to the other, measured perpendicular to the axis of the tooth at the crest, is greater than twice the depth of the carburized layers on the flanks.
A layer of hardfacing is applied to the top and flanks of the tooth stub, forming an apex for the tooth. The layer of hardfacing is much thicker than normally used, preferably equal to or greater than {fraction (3/16)} inch on the crest. The hardfacing layer has an axial depth that is preferably at least 15 percent the axial length of the tooth stub.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of an earth-boring bit of the steel tooth type constructed in accordance of this invention.
FIG. 2 is a sectional view of a tooth of an earth-boring bit as in FIG. 1, but showing a prior art design.
FIG. 3 is a sectional view, taken along the line 3 — 3 of FIG. 4, of a tooth constructed in accordance of this invention.
FIG. 4 is a sectional view of the tooth of FIG. 3, taken along the line 4 — 4 of FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, an earth-boring bit 11 , modified in accordance with the present invention, is depicted. Earth-boring bit 11 includes a bit body 13 having threads 15 at its upper extent for connecting bit 11 into a drill string (not shown). Each leg of bit 11 is provided with a lubricant compensator 17 . At least one nozzle 19 is provided in bit body 13 for directing pressurized drilling fluid from within the drill string and bit against the bottom of the borehole.
The cutters 21 , 23 , generally three (one of which is obscured from view in FIG. 1 ), are rotatably secured to respective legs of bit body 13 . A plurality of inner row teeth 25 are arranged in generally circumferential rows on cutters 21 , 23 , being integrally formed on the cutters, usually by machining. Heel row teeth 29 are located at the outer edges of each cutter 21 , 23 adjacent gage surface 30 .
FIG. 2 illustrates a tooth 27 which in the prior art would be in a heel row in place of heel row teeth 29 (FIG. 1) in the cutter 21 of FIG. 1 . Prior art tooth 27 is formed with a milling cutter which forms a root 31 , inclined flanks 33 , 35 and an elongated crest 37 . One of the flanks 33 , 35 is a leading flank and the other a trailing flank, considering the direction of rotation of cutter 21 .
Tooth 27 has an axis 39 which is substantially perpendicular to the cutter axis 40 of rotation (FIG. 4 ). A carburized layer 41 is formed in the underlying steel of tooth 27 in a conventional process. Carburized layer 41 is generally in the depth range from about 0.030 to 0.140 inch depending upon bit size and application. The depth of carburizing layer 41 is not uniform because of the sharpness of crest 37 . Because of the short distance from one flank 33 to the other flank 35 at crest 37 , a deeper area 41 a of carburizing layer 41 will result at crest 37 . Carburized portion 41 a becomes deeper because of the merging of the carburized layers 41 underlying flanks 33 , 35 . The distance from flank 33 to flank 35 , measured perpendicular to axis 39 at crest 37 , is less than twice the average depth of carburized layer 41 on flanks 33 , 35 .
A layer of hardfacing 43 is applied over tooth 27 . It may be of various types, typically containing tungsten carbide granules in an alloy steel matrix. The thickness of hardfacing 43 on flanks 33 , 35 and on top of crest 37 is about {fraction (1/16)} to ⅛ inch. Heat treating, which includes carburizing, is usually performed after hardfacing. In another type of prior art tooth, shown in U.S. Pat. No. 5,351,771, curved recesses are located at the junctions of the flanks with the crest. If tooth 27 had those recesses, the thickness of hardfacing 43 would be about double in the recesses than on the top of crest 37 and on flanks 33 , 35 . In another type of prior art tooth, a slot is located on the leading flank as in U.S. Pat. No. 5,445,231. If tooth 27 had such a slot, the thickness of hardfacing 43 on the flank over the slot would be about double that of the rest of tooth 27 .
FIG. 3 shows a heel row tooth 29 constructed in accordance with this invention. Tooth 29 has a steel stub 47 which is integrally formed with cutter 21 in a conventional manner by milling. Stub 47 is shorter than the steel portion of tooth 27 of the prior art. Stub 47 extends upward from roots 49 , has flanks 51 , 52 that incline toward each other, and outer and inner ends 53 , 55 . Roots 49 are the valleys between teeth 29 , as shown in FIG. 1 . During rotation about cutter axis 40 (FIG. 4 ), one flank 51 , 52 leads while the other trails. Flanks 51 , 52 join outer and inner ends 53 , 55 , terminating in a top or crest 57 . Top 57 is shown to be flat and perpendicular to tooth axis 58 , but could be of other configurations.
Stub 47 has a carburizing layer 59 that is uniform and of a depth of about 0.080 to 0.120 inch. Carburized layer 59 is formed conventionally after hardfacing. Carburized layer 59 does not have an increased depth layer at the top 57 . The distance between flanks 51 , 52 , measured perpendicular to tooth axis 58 at the junction with top 57 , is substantially greater than twice the depth of carburized layer 59 . The carburized layers 59 on flanks 51 , 52 do not merge with each other at top 57 .
A hardfacing layer 61 is applied to tooth stub 47 in a conventional manner. Hardfacing 61 may be of a variety of types, but preferably includes tungsten carbide granules or particles in an alloy steel matrix. The matrix binder may contain iron, nickel, cobalt and their alloys and has a hardness after application on tooth stub 47 and heat treating in the range from about 53 to 68 RC. The tungsten carbide particles are in a pre-application ratio in a hardfacing tube of about 50 to 80 percent by weight, preferably about 70 percent. Because of its extra thickness on top 57 , hardfacing 61 will be applied in multiple passes, but without allowing the earlier passes to cool substantially. After hardfacing 61 is applied, cutter 21 is heat treated in a conventional manner. The heat treating process creates the carburized layer 59 and also enhances the hardfacing 61 .
Hardfacing 61 is shaped generally to form an extension or apex of stub 47 to resemble the configuration of prior art tooth 27 . The apex of hardfacing 61 includes flanks 63 , 65 which extend generally in the same direction from flanks 51 , 52 , respectively, terminating in a crest 67 . The apex of hardfacing 61 also has outer and inner end portions 69 , 71 which extend in the same direction from tooth stub outer and inner end portions 53 , 55 , respectively. Hardfacing 61 also may have a thinner portion, typically about 0.047 to 0.125 inch, that will cover a portion of tooth stub flanks 51 , 52 and outer and inner ends 53 , 55 .
Flanks 63 , 65 of hardfacing 61 converge to a fairly sharp crest 67 . The overall length of tooth 29 from root 49 to crest 67 , measured along tooth axis 58 , is conventional. However, the thickness 75 of hardfacing 61 measured from top 57 of stub 47 to crest 67 is much greater than previously utilized with this type of hardfacing, being at least {fraction (3/16)} inch. Thickness 75 will normally be twice or more the thickness of hardfacing 61 covering tooth stub flanks 51 , 52 and outer and inner ends 53 , 55 . In the embodiment shown, tooth stub 47 has a shorter axial length 73 , measured along axis 58 from root 49 to top 57 , than axial thickness 75 of hardfacing 67 . However, tooth stub length 73 could be longer than hardfacing thickness 75 . Tooth stub length 73 should not be so long so as to decrease the distance between tooth stub flanks 51 , 52 to a point where their carburized layers 59 merge and become extra deep. For a very large diameter bit having long teeth, the minimum axial thickness 75 of {fraction (3/16)} inch of hardfacing 61 will be not less than 15 percent the axial length 73 of tooth stub 58 . For smaller diameter bits, 8¼ inch or less, the minimum axial thickness 75 of {fraction (3/16)} inch divided by axial length 73 will normally be higher, at least 35 percent.
The invention has significant advantages. Utilizing an extra-thick hardfacing layer reduces the width of the underlying steel crest from flank-to-flank. This blunter underlying or tooth stub top avoids extra-deep carburizing layers at the top of the tooth stub. A shorter tooth stub and a thicker hardfacing layer on top can reduce brittleness and the possibility of breakage without reducing overall tooth length.
While the invention has been shown in one of its forms, it should be susceptible to various changes without departing from the scope of the invention. For example, although shown only on a heel row tooth, the hardfacing in accordance with this invention could also be applied to inner row teeth and various tooth geometries. | An earth-boring bit has a bit body with at least one earth disintegrating cutter mounted on it. The cutter is generally conically shaped and rotatably secured to the body. The cutter has a plurality of teeth formed on it. The teeth have underlying stubs of steel which are integrally formed with and protrude from the cutter. The stubs have flanks which incline toward each other and terminate in a top. A carburized layer is formed on the flanks and the top to a selected depth. The stub has a width across its top from one flank to the other that is less than twice the depth of the carburized layer. A layer of hardfacing is coated on the tops and flanks of the stub, forming an apex for the tooth. | 4 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of 371 of PCT/SE00/02143 filed on Nov. 1, 2000 and foreign application 9909 077-9 file in Sweden on Nov. 18, 1999.
BACKGROUND OF THE INVENTION
Automatic identification systems that include identification devices (also called data carriers, escort memories, cards, or ID tags) that deliver information from the identification devices by coding, modulation and reflection of an incident microwave signal in the form of an information containing sideband, without supplying further energy to the identification device, have been known in the art since the middle of the 1970s. Such RFID systems (Radio Frequency Identification systems) are related to “backscatter technology” and are particularly common in the microwave range, e.g. at 915 MHz, 2.45 GHz and 5.8 MHz. 2.45 GHz is also a frequency band that can be used for other radiation sources, such as RFDC links, for instance (Radio Frequency Data Communication links). This means that interference problems originating from RFDC systems can occur.
The present invention provides an RFID system that is robust with respect to interference from, among others, these RFDC systems, but also with respect to interference from other systems which give rise to interferences that are short and unsynchronized in relation to the identification messages.
As distinct from RFID, RFDC operates with microwave transmitters at both ends of the transmission link. RFDC systems often utilize so called spread spectrum technology, where the RFDC messages are transmitted at different microwave frequencies in accordance with a controlled pattern in order to counteract fading effects and interferences/disturbances, from other systems, and where the frequency hops rapidly between different values, so-called frequency hopping.
RFID systems can also operate in accordance with spread spectrum technology, and the invention can thus also be applied to minimize interferences from such systems, and also to suppress interferences from any other system which gives rise to interferences that are shorter than the identification messages of the RFID system.
One problem with present day identification systems is that they are highly sensitive to interferences from sources that deliver signals at the receiver frequency of the RFID systems, for instance in the 2.45 GHz band, which is freely available for many applications. Examples of interference sources include so-called Bluetooth links, systems according to the 802.11 standard, RFID systems that include so called downlinks (i.e. systems that send short microwave pulses to the identification device in order to activate and/or to send data to the identification device), RFID systems that include battery-free identification devices, which are energized from the microwave transmitter of the reader via a microwave signal that is modulated in some way or another, radar stations, microwave ovens, personal detectors in alarm systems, automatic door openers, video transmission links, etc.
SUMMARY OF THE INVENTION
The present invention relates to an identification device and/or identification reader or write/read unit functioning in the microwave range. The invention is adapted to suppress interferences from primarily communications and/or identification systems that operate in accordance with a so-called spread spectrum technique in the form of frequency hopping, or so-called direct sequency. It also is adapted to suppress interferences from any other system that transmits microwave signals at fixed or hopping frequencies, and where the signal has been modulated. A microwave signal delivered from the reader is received by the identification device, modulated with an information sideband on one side or on both sides thereof and the information sideband(s) is/are reflected back to the reader without supplying said signal with further energy. The data content of the identification device includes redundancy, for instance by including a data checksum in the data message of said identification device. The message in the identification device is repeated unchanged at least two times in sequence, and the identification device message has a longer time duration than the anticipated interference, so that only a part of said message can be disturbed. In the event of the checksum/redundancy control indicating that the message has been disturbed when making a comparison between at least two mutually sequential messages, the reader establishes which data bits deviate between the messages, and, after intermediate storage of the messages in the reader, substitutes these deviating bits between the messages by trial and error until the checksum/redundancy control gives an accepted result and therewith registers the message as being a correct message. Alternatively, when all possible combinations have been tried and a correct result has still not been obtained, the test is continued with all possible combinations of the data content of subsequent messages.
The invention is further characterized in that the write/read unit may be of a kind that transmits pulsated microwave signals. The write/read unit in one particular embodiment varies its frequency between different values, so-called spread spectrum technology, by frequency hopping. In a further embodiment said unit carries out the redundancy check by checksum calculation in accordance with the CRC method. Only messages that fail the redundancy test are tested by substitution of disturbed parts in their identification messages.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to an exemplifying embodiment thereof, shown in the accompanying drawings, in which:
FIG. 1 illustrates an RFID system of the so-called backscatter type;
FIG. 2 illustrates an RFID system in an interfering field;
FIG. 3 illustrates two consecutive identification messages;
FIG. 4 illustrates interferences from a spread-spectrum RFDC system;
FIG. 5 illustrates how interfered messages have been reconstructed; and
FIG. 6 illustrates a technical solution for this reconstruction.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a read unit 1 and an identification device 2 that are interconnected via a microwave signal 3 . The read unit includes a microwave oscillator 4 which irradiates the identification device antenna 14 via the antenna 5 . The electronic unit 7 of the identification device 2 receives, encodes, modulates and reflects the signal from the read unit with information according to the data present in the electronic unit of the identification device, and therewith creates so-called identification messages 8 for the read unit.
The data content of these messages may be pre-programmed in the identification device or may be programmable, for instance, via microwaves or via a contact device not shown, or in some other way.
The identification messages 8 are delivered to a receiver antenna 6 in the read unit. The receiver antenna, however, need not necessarily be separate from the transmitter antenna 5 , but is so shown in the Figure solely for the sake of simplicity.
The microwave signal received from the identification device by the antenna 6 is transposed to a baseband in a mixer 9 in the read unit 1 , by mixing the signal with part of the signal sent by the antenna 5 , so as to re-create the identification messages 8 and pass said messages to the computer part 10 of the read unit.
Identification device data and other information can therewith be made available via the communications channel 13 , for instance by serial communication in accordance with some typical method.
An important function of the system described hitherto is its redundancy check of the identification messages. For instance, if the identification device is located close to its range limit, its signal to the antenna 6 will only marginally exceed the noise level of the system and certain bits in the message will be erroneous, i.e. the recreated message in 8 b will not fully coincide with the message delivered by the identification device in 8 a.
It would be very unfortunate if such errors were reported to superordinate systems. For instance, an automatically identified train travelling at high speed could unintentionally be switched into a railway siding, or an automatically but erroneously identified parking customer could unintentionally cause billing for someone else, etc. This type of error is called a substitution error and is avoided by said redundancy check. In this document, only one redundancy check method, the checksum method, will be mentioned, even though several other methods can be applied to the same end.
Checksum calculations are based on the assumption that the message 8 does not only contain the data 11 to be transmitted, but that corresponding information has also been coded into a checksum 12 , and the checksum has been calculated on the basis of said data in accordance with some formula, for instance CRC16 or CRC32, and therewith has been programmed into the identification device in order to include the message.
The computer part 10 of the read unit is now able to differentiate between correct messages and erroneous messages with the aid of said formula, by comparing the content of the data part 11 with the checksum part 12 . The messages in which checksum and data do not agree are rejected by the computer part 10 , so that these messages cannot be reported further to the superordinate system via the communications channel 13 . So-called substitution error has been eliminated in this way, i.e. such errors where erroneous messages are reported as correct messages even though they are in fact erroneous, for instance by having been distorted by noise. This is known technology, described here to clarify the invention.
FIG. 2 illustrates an RFID system of the aforedescribed type in the presence of interferences, where reference numeral 21 identifies an RFDC transmitter which communicates with one or more other transmitters (not shown) via microwaves. Reference numeral 21 , however, may identify each other type of apparatus that transmits microwaves which may cause disturbances in the communication between identification device 2 and read unit 1 —also including other RFID systems.
However, for the sake of clarity it is assumed that the illustrated transmitter 21 is an RFDC transmitter according to the so-called Bluetooth standard at 2.45 GHz, more specifically communicating in the frequency band of 2400–2480 MHz permitted in accordance with CEPT and other authorities, said band also being assumed as standard for data communication in accordance with IEEE 802.11 and also that the RFID system functions at the frequency band of 2446–2454 MHz accepted by CEPT for identification systems, i.e. the so-called A VI band.
The signal 3 a from the identification device will now have competition from the signal 5 from the RFDC transmitter. If the identification device is located at its range limit, e.g. 10 meters from the read unit, it can be shown theoretically that interference from the signal 5 can be significant even if the RFDC transmitter 21 should be located at a relatively long distance from the read unit, e.g. a distance of 100 meters. The invention is intended to make the RFID system resistant to these interferences.
FIG. 3 shows two successive RFID messages 31 and 32 with identical data fields 33 and checksum fields 34 . The messages are, however, partially disturbed, more specifically in the intervals 35 and 36 . For instance, interval 35 may represent 10 disturbed bits of a total of 100 bits in the data field 33 .
FIG. 4 shows how disturbances, or interferences, according to FIG. 3 can occur.
It is assumed in this embodiment that the RFID system operates in the RFID band 41 , a band, which, for instance, may have a width of 8 MHz at 2450 MHz. The identification messages 31 and 32 are transmitted at the frequency in this band to which the read unit is set, or more specifically close to said frequency on either side or on both sides thereof in the form of a sideband or sidebands that contain identification message data. Naturally, the frequency of the RFID transmitter may hop between different frequencies in the RFID band from time to time, so-called spread spectrum technique. However, since this does not affect the principle of the invention, it is assumed for the sake of simplicity that the illustrated RFID system operates at a fixed frequency.
It is also assumed that the receiver of the read unit is optimized to receive the aforesaid information sideband in the best possible way, i.e. the receiver band is only as wide as is required for the messages to be transmitted in an optimal manner. If the bandwidth, for instance, should be 100 kHz, the data transmission rate of the message should be of the same order of magnitude.
It is assumed that the illustrated RFDC transmission of FIG. 4 operates in accordance with the spread spectrum technique with hopping frequency over a band 44 that includes the RFID band, where the frequency, for instance, hops between 80 different channels over a bandwidth of 80 MHz. The RFDC link continues to transmit data at a relatively high data transmission rate, for instance a rate at which each individual channel takes up a frequency space of 1 MHz in width, wherewith the RFDC transmitter transmits constantly but at hopping frequencies according to the pattern 45 , 46 , 47 , 48 , and so on.
The interference events that occur, and that the present invention protects against, have been shown in FIG. 4 , where the frequency of the RFDC frequency 47 is shown to collide with the RFID message 31 .
Without the aid of the present invention, the earlier described redundancy check would have rejected the message 31 as a substitution error, and successive messages would also have been rejected due to non-agreement of their checksum calculations. The RFID link thus becomes totally blocked by the RFDC link.
FIG. 5 illustrates a testing procedure according to the described invention, and FIG. 6 illustrates a device for carrying out the procedure.
The messages 31 and 32 illustrated in FIG. 3 and originally containing identical data 33 and checksum 34 , but where a number of bits 35 and 36 have been disturbed in accordance with FIG. 4 , result in rejection of both messages.
A processor 61 that in addition to carrying out standard redundancy checks in accordance with the aforedescribed also checks for deviations between mutually successive messages in order to establish possible differences between the messages. The incoming unaccepted messages are placed in a memory bank 62 for successive processing in the processor 61 .
If, for instance, the disturbed messages 31 and 32 are now compared with each other bit for bit, the processor will discover two uncertain areas 51 and 52 in which deviations occur. Nevertheless, the processor draws the conclusion that the two messages are identical, because both checksums 34 are identical. An interference or disturbance event has thus probably occurred.
The processor 61 then tests first the event 55 , by replacing the deviating area or region 52 in the message 31 with the alternative bit pattern 36 , but when carrying out a redundancy check will interpret the message as being erroneous, because the thus changed message 55 now includes errors both at 53 and 54 .
The processor will then test event 56 , by replacing the deviating area or region 51 with corresponding data in message 32 , and will therewith find that the thus changed message 56 agrees with the redundancy check. The message is therewith accepted. The computer part 10 will thus only receive messages when interferences, or disturbances, from different sources, for instance from Bluetooth-type RFDC systems, are filtered out.
In accordance with the present invention, the processor 61 may be given one of a number of different forms, e.g. the form of a gate matrix, and need not contain software. A hardware solution is to be preferred for dealing with simple interference events, as the solution can be carried out very rapidly.
In order to handle complicated interference events, the processor 61 may consist of a signal processor that has powerful mathematical functions, as this facilitates the use of advanced calculation algorithms for interference suppression. It may for example happen that the message contains disturbances at several positions, where a larger number of messages are interfered with in succession, and where disturbances also in the checksum need to be dealt with, and so on.
The illustrated embodiment thus constitutes only a limited description of how interferences, or disturbances, can be filtered out. Moreover, there has been illustrated with the aid of a simple example a technique which filters out those interferences, or disturbances, that can be expected when an RFID system is operated in a frequency range where several different applications are in good agreement with each other, e.g. in the so-called ISM band (Industrial, Scientific and Medical), 2.45 GHz.
Furthermore, there has been shown in the illustrated example solely an RFID system in which a non-modulated microwave signal is transmitted from the read unit, which may be the case when the identification device contains a constantly oscillating circuit for clocking its internal logic and its modulation circuits connected to the identification device antenna.
In another embodiment, the read unit may also be used to activate the identification device, for instance by transmitting pulsed microwave signals that are detected by circuits in the identification device, and therewith, for instance, starting an oscillator incorporated in the identification device for forward clocking of data to the modulator circuits connected to the identification device antenna.
In yet another embodiment, the read unit may transmit pulsed microwave signals for transferring data to the identification device for storage in a memory incorporated in the identification device and/or for controlling the function of said device. Consequently, the read unit is at times also referred to as a write/read unit. | Apparatus and a method for enhancing the interference resistance of so-called RFID systems, wherein identification messages delivered from an identification device are longer than the time for which an anticipated interference or disturbance is calculated to continue, and wherein the messages contain redundancy, such as a checksum. The messages are delivered from the identification device repetitively, and are redundancy checked. In the event of any discrepancy in the redundancy check, such as when the checksum is checked against the data content of the message and is found in disagreement, successive messages are checked bit for bit against each other. Any deviations between otherwise previously rejected messages are assumed to be due to external interference and are thus successively substituted until the redundancy check gives an accepted result, such as through the medium of a checksum check according to the so-called CRC method. | 7 |
REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. application Ser. No. 12/573,278, entitled “FIBER SPECTROSCOPIC PROBE MOUNTABLE ON A MICROSCOPE”, filed on Oct. 5, 2009, by Ryan E. Sullivan, Qingxiong Li, Xin J. Zhou, and Sean X. Wang. The subject matter of the above mentioned U.S. applications is hereby incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention generally relates to a fiber spectroscopic probe, and more specifically to a fiber spectroscopic probe mountable on a microscope.
BACKGROUND
[0003] Raman microscopy is a useful spectroscopic technique that permits nondestructive, spatially resolved measurements within the samples. Conventional Raman microscopes such as those disclosed in U.S. Pat. No. 5,194,912 to Batchelder et al. suffer from bulky sizes, which limits them only to laboratory usages. Recently, with the development of diode lasers as the excitation light source, Raman spectrometers were made as compact attachments that can be mounted onto a standard microscope to convert it into a Raman microscope. Some exemplary apparatus can be found in U.S. Pat. No. 7,102,746 to Zhao and U.S. Pat. No. 7,403,281 to Carron et al., which are hereby incorporated herein as references. Yet the large number of optical components in a Raman spectrometer still places a lower limit on its physical size. As a result, the incorporation of the Raman spectrometer inevitably alters the optical path length of the microscope. Certain modifications have to be made to the microscope to accommodate the Raman spectrometer, which may disturb the microscope's originally designed functions.
[0004] There thus exists a need for an improved spectroscopic accessory that can be mounted onto a standard microscope to add a spectroscopic function to the microscope and in the meantime induces minimum alteration to the optical path of the microscope.
SUMMARY OF THE INVENTION
[0005] It is the overall goal of the present invention to solve the above mentioned problems and provide a fiber spectroscopic probe that can be mounted directly above the objective lens of a standard microscope to add a spectroscopic function to the microscope. The constructed microscope with fiber spectroscopic probe is suitable for micro-sampling, Raman analysis, as well as fluorescence analysis and can be easily reconfigured for different excitation/detection wavelengths. The fiber spectroscopic probe only consists of a minimum number of optical components and is compact enough to induce minimum alteration to the optical path of the microscope.
BRIEF DESCRIPTION OF THE FIGURES
[0006] The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
[0007] FIG. 1 is a schematic side view of a first exemplary embodiment of the fiber spectroscopic probe that is mounted on a microscope;
[0008] FIG. 2 is a schematic top view of the fiber spectroscopic probe of FIG. 1 ;
[0009] FIG. 3 is a schematic side view of a second exemplary embodiment of the fiber spectroscopic probe that is mounted on a microscope; and
[0010] FIG. 4 is a schematic top view of the fiber spectroscopic probe of FIG. 3 .
[0011] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
DETAILED DESCRIPTION
[0012] Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to a fiber spectroscopic probe mountable on a microscope. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
[0013] In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
[0014] FIG. 1 and FIG. 2 show a schematic side view and a schematic top view of a first exemplary embodiment of the fiber spectroscopic probe, respectively. In this exemplary embodiment, the fiber spectroscopic probe 100 is a fiber Raman probe, which can be mounted onto a standard microscope 200 to convert it into a Raman microscope.
[0015] Referring to FIG. 1 , the microscope 200 is a standard light microscope comprising the following components: an epi-illumination light source 206 and a trans-illumination light source 220 for providing illumination, a stage 212 for holding the sample 210 , a nosepiece 202 and a plurality of objective lenses 204 for collecting the reflected or transmitted light from the sample, as well as an eyepiece 216 and a camera 218 as the viewing device. The epi-illumination light produced by the light source 206 is reflected by a beam splitter 208 (preferably a half-silvered mirror) into the main optical path of the microscope. The focus of the microscope can be adjusted though a knob 214 .
[0016] Referring to FIG. 1 and FIG. 2 , the fiber Raman probe 100 comprises an input optical fiber 102 for delivering excitation light from a laser light source (not shown). The laser light from the input optical fiber 102 is collimated by an optical lens 104 and transmits through a band-pass optical filter 106 to remove the out-of-band background noise. The filtered laser light is then reflected by a dichroic beam splitter 108 to be directed toward an output tube 110 . The output tube 110 is enclosed in an adapter member 114 to be mounted onto the microscope 200 in a position directly on top of the nosepiece 202 and the objective lens 204 . The distal end of the output tube 110 comprises two transparent windows (or two openings) 116 and a 45° dichroic beam splitter 112 . The dichroic beam splitter 112 is transmissive to the wavelengths of the illumination light and reflective to the wavelengths longer than that of the laser light such that the laser light is reflected towards the objective lens 204 to be focused onto the sample 210 . Here the laser light shares the same optical path as the illumination light of the microscope. The laser light excites a Raman scattered light (a spectroscopic signal) from the sample 210 , which is collected by the objective lens 204 and then reflected by the dichroic beam splitter 112 into the output tube 110 . The Raman scattered light transmits through the dichroic beam splitter 108 to be reflected by a mirror 118 and directed toward a long-pass optical filter 120 and an optical lens 122 . The long-pass optical filter 120 acts as a Rayleigh rejection filter to remove the Rayleigh scattered light from the Raman scattered light. The optical lens 122 then focuses the Raman scattered light into an output optical fiber 126 to be transmitted to a spectrometer device (not shown) for spectrum analysis. In this exemplary embodiment, the laser light source is preferably a diode laser with its output wavelength in the near infrared (NIR) region. The dichroic beam splitter 108 has a cut-off wavelength near the laser wavelength to reflect the laser light and in the meantime transmit the Raman scattered light at longer wavelengths. The fiber Raman probe 100 may further comprise two fiber adapters 130 and 132 , which allow the user to change the types of output and input optical fibers in accordance to the spectrometer device and the laser light source that are used. For example, the user may choose a single mode laser as the light source and a single mode fiber as the input optical fiber such that the laser light can be focused to a small spot size on the sample to increase the spatial resolution of the Raman microscope. The user may also select a multimode laser light source and a multimode input optical fiber so that the power of the excitation light can be increased to enhance the intensity of the Raman scattering signal.
[0017] Both the input optical fiber 102 and the output optical fiber 126 of the fiber Raman probe 100 have a limited optical aperture of less than a few hundred microns (less than a few microns for single mode fiber). Thus the excitation light can be focused to a small spot size on the sample. In the meantime, the output optical fiber 126 will reject most of the out-of-focus light from the sample. This spatial filtering effect adds a confocal feature to the constructed Raman microscope and allows it to examine a series of sections of the sample at different depths. Two spatial pinholes 124 and 128 (either fixed or adjustable) can be inserted in front of the input end of the output optical fiber 126 and the output end of the input optical fiber 102 , respectively to provide further control of their optical apertures such that this ‘confocal’ spatial filtering effect can be further enhanced.
[0018] The fiber Raman probe 100 contains only a minimum number of optical components. As a result, its thickness can be made very small (e.g. <1 cm) so that the incorporation of the fiber Raman probe only induces a minimum alteration to the optical path length of the microscope. This brings in several advantages. First, the fiber Raman probe 100 can be mounted directly above the nosepiece 202 and the objective lens 204 of the microscope, where the light beam exhibits the smallest spot size in the optical path. Thus the Raman scattered light from the sample can be effectively collected by the fiber Raman probe and in the meantime, the reflected (epi-illumination mode) or transmitted (trans-illumination mode) visible light from the sample 210 will not be blocked. Second, the illumination condition of the microscope (such as Kohler illumination in the epi-illumination mode) will not be disturbed by the incorporation of the fiber Raman probe. Third, the fiber Raman probe does not occupy any viewing port of the microscope hence not affecting its normal viewing function.
[0019] With some minor modifications to its optical components, the same fiber probe 100 can be used for other spectroscopic applications as well. For example, by replacing the NIR laser light source with an ultraviolet (UV) or visible light source and adjusting the spectral property of the optical components correspondingly, the fiber probe can convert a standard microscope into a fluorescence microscope for examining the fluorescence or phosphorescence property of the samples.
[0020] FIG. 3 and FIG. 4 show a schematic side view and a schematic top view of a second exemplary embodiment of the fiber spectroscopic probe, respectively. The fiber spectroscopic probe 300 has a similar structure as does the fiber Raman probe 100 of FIG. 1 and FIG. 2 except that the adapter member 314 is detachable from the spectroscopic probe. The adapter member 314 has a receptacle 334 to secure the output tube 310 of the spectroscopic probe and mount the spectroscopic probe on top of the nosepiece 202 and the objective lens 204 of the microscope 200 . This configuration allows the user to switch between different types of fiber spectroscopic probes without changing the adaptor member, which ensures the alignment of the output optical path of the spectroscopic probe with that of the microscope. In addition, the adaptor member 314 may comprise two or more switchable dichroic beam splitters 312 and 316 at different operating wavelengths such that the user may select a set of excitation/detection wavelengths. For example, the user may switch between a 532 nm fiber Raman probe and a 785 nm fiber Raman probe by simply switching the dichroic beam splitter of the adapter member 314 . This reconfiguration capability allows the user to select the optimum excitation/detection wavelength according to the type of sample to be measured. Alternatively, the adaptor member 314 may comprise a multiband beam splitter (not shown), which has multiple reflection bands at different wavelengths to be used for different excitation/detection wavelengths.
[0021] In a slight variation of the previous disclosed embodiments, the dichroic beam splitter 112 in FIG. 2 or 312 and 316 in FIG. 4 is replaced with an optical mirror. The optical mirror has a physical size comparable to the beam size of the laser light yet smaller than the beam size of the illumination light such that only a portion of the reflected (epi-illumination mode) or transmitted (trans-illumination mode) illumination light from the sample will be blocked. Thus the normal viewing function of the microscope is not disturbed by the incorporation of the fiber spectroscopic probe. The transmissive/reflective property of the optical mirror is wavelength-independent. Hence it can be used for all excitation/detection wavelengths.
[0022] In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. The numerical values cited in the specific embodiment are illustrative rather than limiting. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued. | A fiber spectroscopic probe that can be mounted directly above the objective lens of a standard microscope to add a spectroscopic function to the microscope. The constructed microscope with fiber spectroscopic probe is suitable for micro-sampling, Raman analysis, as well as fluorescence analysis and can be easily reconfigured for different excitation/detection wavelengths. The fiber spectroscopic probe only consists of a minimum number of optical components and is compact enough to induce minimum alteration to the optical path of the microscope. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of commonly owned U.S. patent application Ser. No. 08/102,830, filed Aug. 6, 1993, now U.S. Pat. No. 5,377,636.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to solenoid operated pump-line-nozzle fuel injections systems for internal combustion engines. In particular, to such fuel injection systems in which an inline injection pump utilizes a solenoid-operated control for regulating injection timing and the quantity of fuel injected.
2. Description Of Related Art
Inline injection pumps and pump-line-nozzle fuel injections systems using such pumps are old and well known. A discussion of several examples of such pumps and systems, and the efforts taken to improve their construction so that the increasing demands for low exhaust emissions can be met, can be found, for example, in SAE publication no. SP-703, Recent Developments in Electronic Engine Control & Fuel Injection Management, paper nos. 870433, 870434 and 870436, pages 37-42, 43-51 & 65-77 published February, 1987. Inline pumps have a separate pumping cylinder for supplying fuel to each injection nozzle of the injection system, to which it is connected by a fuel line (hence, the name pump-line-nozzle injection system), a respective injection nozzle being provided for each engine cylinder. While inline pumps, such as those described in the papers cited above, are able to independently control injection timing and injection quantity, none of the known inline pumps produces individual cylinder control of both timing and fuel quantity on an infinitely adjustable basis; that is, typically such pumps having a control rack which adjusts all pumping cylinders in the same manner at the same time, and frequently using a step-wise adjusting driver.
Another type of pump used in pump-line-nozzle systems is a distributor pump. Examples of such pumps can be found in U.K. Patent Nos. 442,839 and 1,306,422 as well as U.S. Pat. Nos. 3,035,523 and 4,502,445, and a system and component description of both inline and distributor pumps can be found at page 24 of the above-cited SAE publication SP-703 in paper no. 870432 as well. In distributor pumps, only a single pumping cylinder is provided and a rotary distributor determines which injection nozzle will receive a specific dose of fuel. Inherently, such pumps cannot provide individual cylinder control since they lack individual pumping cylinders to control; however, as indicated, e.g., in U.S. Pat. Nos. 2,947,257 and 2,950,709, such distributor pumps can be constructed as multicylinder pumps as well (but in such a case they essentially become inline pumps, with a rack, cam or other single regulating mechanism being used to control "the whole of the injectors" and to insure that fuel delivery "is the same for all the cylinders"), so that individual cylinder control is still not obtained.
Another type of fuel injection system, which is fundamentally different from pump-line-nozzle systems, is the unit injector fuel injection system. In such a system, a positive displacement pump is used to supply fuel at low pressure, typically at constant pressure of e.g., 30 psi, to a respective unit fuel injector associated with each engine cylinder. The unit injectors, themselves, regulate the timing and metering of the fuel into the respective engine cylinder and also develop the high pressure, e.g., at least 15,000 psi at which the fuel needs to be injected into the engine cycle if the requirements for increased fuel economy and decreased emissions are to be achieved.
Solenoid operated fuel injectors of the unit injector type having characteristics of the type sought to be obtained with the inline pump of the pump-line-nozzle injector system of the present invention have been in use for some time, and an example of such an injector can be found in commonly-owned U.S. Pat. No. 4,531,672 to Smith. In this type of injection, a timing chamber is defined between a pair of plungers that are reciprocatingly displaceable within the bore of the body of the injector and a metering chamber is formed in the bore below the lower of the two plungers. A supply rail in the engine delivers a low pressure supply of fuel to the injector body. To control this supply of fuel, a solenoid valve is disposed in the flow path between the fuel supply rail and the injector bore and the plungers block and unblock respective ports leading from injector body fuel supply circuit into the timing and metering chambers.
During the operation of such an injector, the port to the timing chamber is opened during retraction of the plungers to allow fuel to enter the timing chamber. During the injector downstroke, the timing port is closed by the upper plunger, and then, the metering port is opened to direct the supply of fuel into the metering chamber. During the entire time, from the start of the timing period through the end of the metering period, the solenoid valve remains open.
In an existing unit injector design, sold by the Cummins Engine Co. under the CELECT trademark, shown in FIGS. 1-3, improved performance is achieved. In this existing unit fuel injector 1, as shown in FIG. 1, initially, during the retraction stroke, with the solenoid valve 3 closed, the metering plunger 5 and the timing plunger 7 rise together, and fuel under rail pressure is metered into the metering chamber 9. When the proper quantity of fuel has been metered, the solenoid valve 3 is opened (FIG. 2), allowing fuel to flow into the timing chamber 11, causing the pressure at the top and bottom of the metering plunger to be equalized, thereby stopping movement of the metering plunger 5 while the timing plunger 7 continues to rise, and the timing chamber 11 to fill, as the retraction stroke is completed.
During the downstroke, prior to the time at which injection is to commence, as shown in FIG. 3, the solenoid valve 3 remains open and fuel is forced back out of the timing chamber 11, through the solenoid valve 3 into supply circuit. A relief valve assembly 15 is provided to vent high pressure spikes from the rail side of the injector 1 to the drain side thereof (enlarged detail of FIG. 3). More specifically, the relief valve assembly 15 comprises a valve member 15a which is urged against a relief port 15b by a coil spring 15c which is disposed in a barrel member 17, the upper surface of which forms the bottom wall of the metering chamber 5 and which contains channels through which fuel flows between the fuel inlet port and the metering chamber and from the metering chamber to a drain passage 21. When the pressure of the backflowing timing fluid exceeds that of spring 15c, the valve member 15a unblocks relief port 15b, thereby opening a path from the fuel supply circuit to drain passage 21. At the end of the injection phase, when the solenoid 3 is closed, the top edge of the metering plunger 5 passes below at least one timing fluid spill port 23, thereby evacuating the timing chamber 11 via the drain passage 21. Additionally, passages 5a in the metering plunger 5 are brought into communication with at least one spill port 25 by which a small quantity of fuel is spilled to the fuel supply circuit. Then, the described cycle of events is repeated.
However, while unit fuel injector fuel injection systems are available by which the amount of fuel injected and timing of its injection can be independently and infinitely adjusted on a individual cylinder and cycle-to-cycle basis, using a relatively simple, single solenoid control for each injector, unit injectors, due to increased tasks associated therewith in comparison to the injection nozzle of a pump-line-nozzle injection system, is relatively large in comparison to the injection nozzle of pump-line-nozzle injection systems. As a result, the use of unit fuel injector systems has been confined to large, heavy duty engines since insufficient space exists in the engine valve area of smaller engines to accommodate unit fuel injectors. Thus, there still is a need for further improvements to pump-line-nozzle fuel injector systems of the type to which this invention is directed, in order to provide the degrees of precision control needed to meet the competing demands for both increased fuel economy and decreased engine exhaust emissions.
In another unit fuel injector system development of the assignee of the present application, which is disclosed by several of the present inventors with another inventor in co-pending U.S. patent application Ser. No. 08/208,365, a metering system for controlling the amount of fuel supplied to the combustion chambers of a multi-cylinder internal combustion engine comprises a fuel pump for supplying fuel at low pressure to a first and a second group of unit fuel injectors via first and second fuel supply paths, respectively. A first solenoid-operated fuel control valve, positioned in the first fuel supply path between the fuel pump and the first set of unit fuel injectors, controls the flow of fuel to the first set of unit fuel injectors while a second solenoid-operated fuel control valve, positioned in the second fuel supply path between the fuel pump and the second set of unit fuel injectors, controls the flow of fuel to the second set of unit fuel injectors. Only one injector from the first group and one injector from the second group of unit fuel injectors can be placed in a mode for receiving fuel from the fuel pump at any given time during the operation of the engine, thereby allowing the metering of each injector to be independently controlled over a greater time period. The system may also include a first solenoid-operated timing fluid control valve positioned in a first timing fluid supply path associated with the first group of unit fuel injectors and a second solenoid-operated timing fluid control valve positioned in a second timing fluid supply path associated with the second group of unit fuel injectors, wherein at any given time only one injector from the first group and one injector from the second group of injectors can be placed in a timing fluid receiving mode. The injectors are capable of being in the fuel receiving mode, establishing a metering period, and the timing receiving mode, establishing a timing period, at the same time to increase the amount of time available for metering both timing fluid and fuel. By grouping the various injectors based on the order of injection, so that the injectors from each group are placed in the injection mode in spaced periods throughout each cycle of the engine, e.g. injectors from other groups injecting in the period of time between each injection mode, the system can be designed to permit longer metering and timing periods.
The unit injectors may include an injector body having an injection orifice at one end and a cavity communicating with the orifice and containing inner and outer plunger sections arranged to form a variable volume metering chamber between the inner plunger and the orifice for receiving fuel during the metering period and a variable volume timing chamber between the inner and outer plungers for receiving timing fluid during the timing period. The solenoid-operated valves are moved between open and closed positions during the metering and timing periods to allow fuel and timing fluid, respectively, to flow to the metering and timing chambers thereby defining metering and timing events, respectively. The metering and timing events for each injector occur only between periodic, relatively quick injection strokes of the plungers thereby minimizing the operating response time requirements of the control valves. The fuel supply passage to the metering chamber of each injector contains a spring-loaded check valve for preventing the flow of fuel out of the metering chamber while also preventing combustion gases from entering the supply passage and disturbing the effective control of metering. The injectors may be either open or closed nozzle injectors. A pressure regulator maintains the pressure in the timing fluid and fuel supply paths at a substantially constant pressure. Also, flow control valves may be provided downstream of the fuel pump to provide a fixed flow rate independent of fuel pressures upstream and downstream of the flow control valves.
SUMMARY OF THE INVENTION
In view of the foregoing, it is an object of the present invention to provide an pump-line-nozzle fuel injector system in which an inline injection pump utilizes a solenoid-operated control for regulating injection timing and the quantity of fuel injected so as to enable the amount of fuel injected and timing of its injection to be independently and infinitely adjusted on a individual cylinder and cycle-to-cycle basis in a manner minimizing the number of solenoid valves required as well as the operating pressure and response time requirements for the solenoid valves.
In connection with the preceding object, it is a more specific object to adapt known unit fuel injector technology to the environment of pump-line-nozzle systems where the compressibility of the fuel has a significant effect due to the length of the line between the pump and the nozzle.
A still further object is to provide an inline pump in which a pair of solenoid valves control metering and timing for a group of pumping cylinders in accordance with time-pressure (TP) principles (the quantity metered being determined by the amount of time that the respective valve is open), the pumping cylinders being grouped based on the order of injection, so that only one pumping cylinder from each group is placed into an injection mode and a timing mode at any given time.
Yet another object of the present invention is to achieve the foregoing objects through the use of the cam profile of the operating cam used to drive timing and metering plungers of each pumping cylinder as the mechanism by which initiation of injection is controlled.
These and other objects are achieved in accordance with a preferred embodiment of the invention in which a low pressure supply pump is coupled to a high pressure pump having a plurality of pumping cylinders, each of which has a cam-driven timing plunger and a floating metering plunger. During the retraction stroke, flow to a timing chamber formed between the pistons is controlled by a first solenoid valve while the fuel flow into a metering chamber is controlled by a second solenoid valve. During metering, the discharge side of the pump is closed relative to a high pressure delivery line by a delivery valve. During the compression stroke, return flow is precluded by check valves in the supply lines to the timing and metering cylinders. Most importantly, since only one pumping cylinder of each pumping group undergoes its metering and injection phases at a given time, the timing and metering plungers of the other pumping cylinders being held in their maximally inwardly displaced, end-of-injection positions at that time, a single set of timing and metering solenoid valves can be used to individually meter fuel into the metering chamber and timing fluid into the timing chamber, independently and with the quantities metered being infinitely adjustable on a individual cylinder and cycle-to-cycle basis. Once the fuel is sufficiently pressurized, the delivery valve opens and the fuel is delivered to the respective injector via the high pressure delivery line from the particular one of the pumping cylinders.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, show a preferred embodiment in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is schematic cross-sectional depiction of an existing unit fuel injector during a metering phase;
FIG. 2 is schematic cross-sectional depiction of the FIG. 1 fuel injector during a timing chamber filling phase;
FIG. 3 is schematic cross-sectional depiction of the FIG. 1 fuel injector during a timing phase;
FIG. 4 is a schematic diagram of a pump-line-nozzle fuel injection system in accordance with the parent application;
FIG. 5 is a schematic diagram as in FIG. 4, but of a modified embodiment of the parent application.
FIG. 6 is a schematic diagram of a pump-line-nozzle fuel injection system in accordance with the present application;
FIG. 7 is a schematic diagram of a pump-line-nozzle fuel injection system of FIG. 6 showing the grouping of plural pumping cylinders with respect to respective fueling and timing solenoid valves; and
FIGS. 8a-8c are cross-sectional schematic views of a portion of the pump-line-nozzle fuel injection system of FIG. 6, showing the plunger positions and cam angles of the pumping cylinders of a first set of pumping cylinders at an engine crank angle of 0°, 120° and 240°, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 4, the pump-line-nozzle fuel injection system 10 in accordance with the parent application can be seen to be comprised of an inline high pressure pump 12 having a plurality of identical pumping cylinder units C (only one of which is shown), each of which is connected by a high pressure line 14 to a respective one of a plurality of engine fuel injectors 16 (only one of which is shown), and corresponding in number to the number of cylinders of the internal combustion engine with which it is to be used (not shown). A low pressure supply pump 18 draws fuel from a fuel supply (such as a vehicle fuel tank) and supplies the fuel to each of the pumping cylinder units C of inline pump 12, via a fuel supply circuit 20, at a pressure of, e.g., about 30 psi, which is held substantially constant by a pressure regulator 22.
Since the construction and operation of all of the pumping cylinder units C of inline pump 12 are identical, for simplicity, only the single pumping cylinder unit C shown will be described in detail, it being understood that such descriptions are not limited to only that one cylinder unit. On the other hand, it should be realized that each of the several pumping cylinder units of pump 12 is independently, individually controllable with respect to the timing and quantity of fuel caused to be injected thereby under the control of the Electronic Control Module (ECM) 24, as will be explained further below.
As illustrated, each pumping cylinder unit C comprises a timing plunger 26 and a metering plunger 28 that are reciprocatingly received in a bore of the pump 12. The timing plunger 26 is spring-loaded against a tappet 31 which rides on the periphery of a respective lobe of a pump cam shaft 33, pump cam shaft 33 being linked to the engine drive shaft to rotate in synchronism therewith. In view of the high pressures generated by the pumping unit C, e.g., approximately 15,000-18,500 psi, to at least partially compensate for the length of high pressure line 14 and the compressibility of the fuel therein, timing plunger 26 is, preferably, larger in diameter, about one-third larger, than the metering plunger 28 so as to achieve a fast pumping rate. For example, it has been found to be suitable to use a timing plunger of 12 mm diameter with a metering plunger of 9 mm.
A variable volume timing chamber 40 is defined in the bore of the pumping cylinder between the timing plunger 26 and a facing end of the metering plunger 28, and a metering chamber 42 is defined between the opposite end of the metering plunger and a delivery valve 44. The flow of timing fluid (which may be engine lubrication oil, or fuel as illustrated) into and out of the timing chamber is controlled by a solenoid valve 46, and return flow out of the metering chamber 42 is prevented by a metering check valve 48.
During the retraction stroke of timing plunger 26, initially, metering plunger 28 is drawn down with it and fuel flows into the metering chamber from a respective branch 20a of the fuel supply circuit 20. At the same time, solenoid valve 46 prevents timing fluid from flowing into timing chamber 40. When the ECM 24 determines that the appropriate quantity of fuel has been metered, it causes solenoid valve 46 to open. This starts the flow of timing fluid, in this case fuel via a timing fluid flow branch 20b of fuel supply circuit 20, into the timing chamber 40. This also has the effect of balancing the pressures at the opposite sides of the metering piston 28, so that it stops moving and floats relative to timing plunger which continues to move downward as it follows the cam 33. Furthermore, to insure that the metering plunger is held stationary and to prevent return flow leakage through the check valve 48, a spring 50 acts between the facing ends of the timing and metering plungers in order to prevent the metering plunger from drifting downward and to maintain enough pressure on the fuel in the metering chamber 42 to close the check valve 48. In this way, a precisely metered quantity of fuel to be injected is trapped in the metering chamber 42 once solenoid valve 46 opens and the timing chamber 40 fills with timing fluid (fuel).
As the tappet 31 continues to track the curvature of the lobe of cam 33, at the end of the retraction stroke, the timing plunger is caused to move in its compression stroke toward the metering piston and the discharge end of the pumping cylinder. However, until the ECM 24 determines that the appropriate time for commencement of injection has arrived, solenoid valve 46 remains open and the fuel is forced back out of the timing chamber 40, through the solenoid valve 46 to the supply circuit 20. To prevent this outflow of fuel from affecting the supply of fuel to travel to other pumping cylinder units via their supply branches 20a, a relief valve can be provided to vent high pressure spikes from the supply side of the system 10 to the drain side thereof, such a relief valve being schematically depicted by block 52 at the manifold junction from which the branches 20a, 20b extend; however, it will be appreciated that the relief valve 52 can be placed at any of a number of other locations instead.
Once the ECM 24 determines that the appropriate time for initiation of injection has arrived, it triggers closing of solenoid valve 46, thereby trapping the remainder of the fuel serving as the timing fluid in the timing chamber 40. This trapped fuel acts as a hydraulic link between the timing plunger 26 and the metering plunger 28, and thus, causing the upward force on the timing plunger 26 to be transferred to the metering plunger 28, pressurizing the fuel in the metering chamber 42. When the pressure of the fuel in the metering chamber 42 reaches the required level, e.g., 15,000-18,500 psi, the delivery valve 44 pops open, allowing the fuel to flow from the metering chamber 42 into the high pressure line 14 and into the injector 16. Because of the nozzle spray holes are closed by a needle valve of injector 16, continued upward movement of the plungers 26, 28, causes the pressure of the fuel to increase, and when the needle valve opening pressure is reached, the fuel causes the needle valve in the nozzle of injector 16 to open, so that the fuel exits spray holes of the nozzle into the combustion chamber of the engine. However, since the nozzle holes for a flow restriction, the fuel pressure will steadily increase as injection progresses and the plungers 26, 28 are driven further into the cylinder bore by the action of the tappet 31 and cam 33.
Injection is terminated when a T-shaped spill passage 54 in the metering piston 28 is brought into communication with a spill line 56, at which point the pressure in the metering chamber drops rapidly as the remaining fuel is spilled therefrom, thereby allowing the needle valve in injector 16 to close abruptly. The delivery valve 44 also closes and is designed to control line dynamics in high pressure line 14 so as to prevent secondary injection and insure a positive end to fuel injection. Immediately after the metering spill passage 54 reaches spill line 56, the end of the metering plunger 28, bounding the timing chamber 40, clears a drain port to drain line 58, spilling the timing fluid from the timing chamber 40 to drain as the timing plunger completes its inward movement, thus, completing the injection cycle.
The ECM can be of conventional design receiving various engine operating parameter inputs P 1 , P 2 . . . P n , such as engine speed, load, etc. and determining the appropriate times for opening and closing the solenoid valves 24 on the basis thereof and can also adjust for the compressibility of the fuel and the length of high pressure lines 14. Due to similarities between the embodiments of the parent case and the above-noted CELECT unit injector, they can share such components as the ECM, sensors and solenoid valve, and will enable service tools used with that unit injector for calibration and problem diagnosis to be used with the pump-line-nozzle system of parent case, thereby increasing its cost effectiveness, and it can be implemented on existing engines without redesign of the engine head or block. Likewise, no significant changes from the system and operation described above are needed to implement the mentioned ability to use lubrication oil as the timing fluid instead of fuel; that is, timing fluid line 50b and timing fluid drain line 58 need only be connected to the lubrication oil circuit instead of the fuel supply circuit as represent in FIG. 5 with the engine oil pump serving to supply lubrication oil to the timing chamber when the solenoid valve 46 opens.
In this context, the nature and significance of the further developments incorporated into the preferred embodiment of a pump-line-nozzle fuel injection system 10' of the present application shown in FIGS. 6-8. In the following description, emphasis is placed on the points of distinction between system 10' and system 10 in accordance with the parent application, those attributes not being described being the same, a repeated description thereof having been omitted for the sake of brevity. Accordingly, those components which remain unchanged bear the same reference numerals while those which have been modified are distinguished by prime (') designations and new reference characters being applied to components having no counterpart.
As can be seen from FIGS. 6-8, pump-line-nozzle fuel injection system 10' is comprised of an inline high pressure pump 12' having a plurality of identical pumping cylinder units C', in the example shown in FIG. 7, pump 12' (for use with a six cylinder engine, not shown) has six cylinder units C' 1 to C' 6 , which receive fuel from a low pressure pump 18 via a supply circuit 20 containing a pressure regulator 22, and which deliver fuel at high pressure via a high pressure line 14 to a respective fuel injector 16. As also represented, the cylinder units C' 1 to C' 3 and C' 4 to C' 6 are arranged to be grouped together so that flow to them from a common fueling branch 20'a and a common timing branch 20'b is controlled by a respective fueling solenoid 46'a and timing solenoid 46'b together with a check valve 48'a, 48'b for each cylinder. This is in contrast to the case, explained above, for the embodiments of the FIGS. 4 and 5, where each cylinder unit C has a solenoid 46 in flow path 20b to each timing chamber and a check valve 48 in the flow path 20a to each metering chamber. The arrangement of FIGS. 6-8, therefore, is advantageous in that only four solenoid valves are required instead of six (offering reductions in system size, weight and cost), and these solenoids need only act on low pressure fluid (less than 300 psi) and their response time requirements can be reduced (e.g., to 2 to 12 msec).
Furthermore, unlike the case of the embodiments of FIGS. 4 and 5, where the solenoid valve 46 controls both the quantity of fuel injected and the timing at which injection is initiated, thereby requiring high sensor accuracy and high solenoid valve responsiveness, the embodiment of FIGS. 6-8, utilizes the profile of camshaft 33' to determine when injection is initiated with the quantities of timing fluid and fuel metered being controlled by the separate solenoid valves 46a, 46b under the control of the electronic control module ECM. In particular, for each group of cylinder units C' 1 to C' 3 and C' 4 to C' 6 , only cylinder unit C' is active for receiving fuel and time fluid at any given time.
That is, as can be seen from FIGS. 8a-8c viewed together, as one pumping unit C', of a group of three pumping units, has completed its injection stroke (FIG. 8a), another one of the pumping units has commenced its metering phase (FIG. 8c). At the same time, the third pumping unit (FIG. 8b) remains in its fully extended, end-of-injection position, on the outer base circle of the cam surface of its cam 33'. Put another way, at any given time only one pumping cylinder C' of each pumping group is in a metering and injection phase, the others being held against downward movement. In this way, the single fueling solenoid valve 46'a and the single timing solenoid valve 46'b can control flow to metering and timing chambers of all pumping cylinders C' of the group with the cams 33' controlling the initiation of injection. During injection, the check valves 48'b, 48'a serve to prevent return flows from the timing and metering chambers 40, 42 back through the solenoid valves 46'b, 46'a. Opening and closing of the solenoid valves 46a, 46, is set by the ECM on the basis of various engine operating parameter inputs, such as engine speed, load, etc. as with the embodiment of FIGS. 4 and 5, with the amount of fuel/timing fluid metered being a function of the pressure in the supply circuit 20 and the amount of time that the respective solenoid valve 46a, 46b is open while the tappet 31 and plunger 26 are descending along the metering (inwardly descending) portion of the cam surface of cam 33'.
This construction and operation causes the fuel to be metered immediately before it is injected instead of over almost a full rotation of the cam, improving engine control and response time, especially at low engine speeds. Furthermore, the timing of the opening and closing of the solenoid valves relative to camshaft position becomes less critical since the valves only have to be open during the metering period; injection timing is controlled by the camshaft profile and metered quantity of fuel and not by when the solenoid is actuated (as in the embodiment of FIGS. 4 & 5). As a result, problems related to position sensor accuracy and gear train torsional effects are eliminated.
Additionally, with the above-described system, the possibility also exists to vary the injection pressure electronically. That is, a common drain line 59 is connected to all of the fuel injectors 16. A drain solenoid valve 60 is disposed in the common drain line 59 and forms a pressure control means for creating a backpressure in drain line 59 between injections, and in turn, this increases the initial pressure in the high pressure lines 14 by acting in a closing direction on a closing needle valve of the injectors 16 or on the delivery valve 44. It has been found that a higher initial pressure in the high pressure line 14 produces an increase in the injection pressure by approximately the same amount as the backpressure-induced increase.
While only a preferred embodiment in accordance with the present invention has been shown and described, it is understood that the invention is not limited thereto, and is susceptible to numerous changes and modifications as known to those skilled in the art. Therefore, this invention is not limited to the details shown and described herein, and includes all such changes and modifications as are encompassed by the scope of the appended claims.
Industrial Applicability
The present invention will find a wide range of applicability for small and midrange engines, especially diesel engines, requiring full electronic fuel control to reduce emissions and improve fuel consumption. Furthermore, it will be particularly attractive to those who also make or use engines having unit injector type fuel injection systems due to the opportunities for increased cost effectiveness. | A pump-line-nozzle fuel injection system in which a low pressure supply pump is coupled to a high pressure in-line pump having a plurality of pumping cylinders, each of which has a cam-driven timing plunger and a floating metering plunger. During the retraction stroke, flow to a timing chamber formed between the pistons is controlled by a first solenoid valve while the fuel flow into a metering chamber is controlled by a second solenoid valve. During metering, the discharge side of the pump is closed relative to a high pressure delivery line by a delivery valve. During the compression stroke, return flow is precluded by check valves in the supply lines to the timing and metering cylinders. Most importantly, since only one pumping cylinder of each pumping group undergoes its metering and injection phases at a given time, the timing and metering plungers of the other pumping cylinders being held in their maximally inwardly displaced, end-of-injection positions at that time, a single set of timing and metering solenoid valves can be used to individually meter fuel into the metering chamber and timing fluid into the timing chamber, independently and with the quantities metered being infinitely adjustable on a individual cylinder and cycle-to-cycle basis. Once the fuel is sufficiently pressurized, the delivery valve opens and the fuel is delivered to the respective injector via the high pressure delivery line from the particular one of the pumping cylinders. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of copending U.S. application Ser. No. 10/082,447, filed Feb. 22, 2002, entitled “METHODS OF FORMING AND USING A CORSAGE BAG”, which is a continuation of U.S. application Ser. No. 09/455,275, filed Dec. 6, 1999, entitled “ARTICLE AND METHODS OF PRODUCING SAME”, now abandoned.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a bag and more particularly, but not by way of limitation, to a bag that is capable of encompassing an item such as a corsage. The present invention also relates to methods of making such a bag as well as methods for its use.
[0004] 2. Brief Summary of the Related Art
[0005] Bags and processes for producing bags are well known in the art. In the past, such bags required numerous seals, folds, and adhesive material covering the blank of material from which the bag was formed. The materials involved in such a process and article can be quite costly and cause the bag to be economically unfeasible for use. Therefore, new and improved bags and methods for producing such bags requiring less material and adhesive are being sought.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0006] [0006]FIG. 1 is a pictorial plan view of a sheet of material employed to form a bag in accordance with the present invention.
[0007] [0007]FIG. 2 is a pictorial representation of an articulated form of a bag of the present invention formed from the sheet of material of FIG. 1.
[0008] [0008]FIG. 3 is a pictorial plan view of another sheet of material employed to form a bag in accordance with the present invention.
[0009] [0009]FIG. 4 is a pictorial representation of an articulated form of a bag of the present invention formed from the sheet of material of FIG. 3.
[0010] [0010]FIG. 5 is a pictorial plan view of another sheet of material employed to form a bag in accordance with the present invention.
[0011] [0011]FIG. 6 is a pictorial representation of an articulated form of a bag of the present invention formed from the sheet of material of FIG. 5.
[0012] [0012]FIG. 7 is a pictorial plan view of yet another sheet of material employed to form a bag in accordance with the present invention.
[0013] [0013]FIG. 8 is a pictorial representation of an articulated form of a bag of the present invention formed from the sheet of material of FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
[0014] According to the present invention, a bag is provided for encasing an item, such as a corsage. Broadly, the bag is constructed from a sheet of material having a bonding material disposed on isolated and individualized sections of the sheet of material. Once the bonding material is on the sheet of material, it is articulated into a bag having fin and/or lap seams at the point of sealing. In one embodiment, the bonding material may be a heat sealable lacquer which is applied to isolated and individualized sections of the sheet of material.
[0015] Referring now to the drawings, and more particularly to FIG. 1, shown therein and designated by reference numeral 5 is a sheet of material. The sheet of material 5 is articulated into a bag 10 as shown in FIG. 2.
[0016] The term “sheet of material” when used herein means at least one flexible sheet of material. The thickness of the sheet of material may vary, but generally the sheet of material will have a thickness in a range from about 0.0002 mil to about 30 mil, and more desirably from about 0.01 mil to about 20 mil. The sheet of material may be any material capable of being articulated into a bag configuration, such as polymeric film, foil, paper, tissue, laminations and combinations thereof. The sheet of material may have a substantially textured surface. The term “paper” as used herein, means treated or untreated paper, corrugated paper or cardboard or any other form of paper material. The term “polymeric film” means a synthetic polymer such as polypropylene or a naturally occurring polymer such as cellophane. A polymeric film is relatively strong and not as subject to tearing as might be the case with paper or foil.
[0017] When the sheet of material is a polymeric film, a flexible sheet of liquified thermoplastic film can be extruded from an extruder in a conventional and well known manner. The flexible sheet of liquified thermoplastic film can be passed through a cooler which cools the liquified thermoplastic film into a sheet of solidified thermoplastic film, i.e. the sheet of material. The sheet of material may also be formed of two or more sheets of material which have been laminated or adhesively connected to one another.
[0018] The sheet of material may also vary in color. Further, the sheet of material may be provided with designs or decorative patterns which are printed, etched, and/or embossed therein using inks or other printing materials. When printed and embossed, the design or decorative patterns may be in register, may be out of register, or may be partially in register and partially out of register. An example of an ink which may be applied to the surface of the sheet of material is described in U.S. Pat. No. 5,147,706 entitled “Water Based Ink on Foil and/or Synthetic Organic Polymer” issued to Kingman on Sep. 15, 1992 and which is hereby incorporated herein by reference. Additionally, the sheet of material may have various colorings, flocking and/or metallic finishes, or other decorative surface ornamentation applied separately or simultaneously or may be characterized totally or partially by pearlescent, translucent, transparent, iridescent or the like qualities. Each of the above named characteristics may occur alone or in combination. The sheet of material may also be opaque, translucent, partially clear, and/or tinted yet having some transparency.
[0019] As shown in FIG. 1, the sheet of material 5 has a first surface 30 , the first surface 30 having a first edge portion 40 , a second edge portion 50 , and a third edge portion 55 . A bonding material 58 is disposed on a portion of the first surface 30 such that the bonding material 58 extends along the first edge portion 40 , the second edge portion 50 , and the third edge portion 55 substantially as shown in FIG. 1. Thus, the first, second, and third edge portions 40 , 50 , and 55 of the first surface 30 define areas of adhesion 57 . The remaining portion of the sheet of material 5 , which is free of adhesive, defines a substantially open area 59 which does not have the bonding material 58 thereon.
[0020] The bonding material 58 may be disposed in a continuous manner across the entirety of the first edge portion 40 , the second edge portion 50 , and the third edge portion 55 of the first surface 30 . In an alternative embodiment, the bonding material 58 may be selectively applied in such a manner as to not completely cover the first edge portion 40 , the second edge portion 50 , and the third edge portion 55 . In this embodiment, the bonding material 58 may be applied as a plurality of dots, strips, or dabs of the bonding material 58 which are applied to alternating areas of the first edge portion 40 , the second edge portion 50 , and the third edge portion 55 . Furthermore, the bonding material 58 can be applied in any geometric form and in any pattern. In any event, it is to be appreciated that the bonding material 58 is not applied to the entirety of the sheet of material 5 , but rather to selective parts of the sheet of material 5 to leave the open area 59 on the first surface 30 of the sheet of material 5 .
[0021] The bonding material 58 may be applied to the sheet of material 5 in any manner which allows for the timely and economical placement of the bonding material 58 onto the sheet of material 5 . For example, the bonding material 58 may be printed onto the sheet of material 5 by brushes, rollers, wires, sponges, and/or other mechanical and/or automated processes. Furthermore, the bonding material 58 may be printed onto the sheet of material 5 with a jet printer, such as an ink jet printing apparatus. In any event, any mechanical or automated process which allows for the correct placement of the bonding material 58 onto the sheet of material 5 is contemplated for use.
[0022] The term “bonding material” may be any material capable of bondingly holding at least two surfaces in a substantially adjacent position. The bonding material may be a hot stamped adhesive, a pressure adhesive, a hot melt adhesive, a water-proof adhesive, a cohesive, a heat sealable lacquer and combinations thereof. The term “heat sealable lacquer” as used herein means a coating substance consisting of resinous materials, such as cellulose esters, cellulose ethers, shellac, gum, alkyd resins and the like, which are dissolved in a solvent that evaporates rapidly on application such as ethyl alcohol, thereby leaving a tough, adherent film. Lacquers which are useful in the present invention maybe mixtures, such as lacquers produced by mixing styrene-acrylic emulsions, such as Lucidene 603 and Lucidene 395 (Morton International, Inc., 100 North Riverside Plaza, Chicago, Ill. 60606) with a non-ionic surfactant, such as Sufynol 465 (Air Products and Chemicals, Inc., 751 Hamilton Boulevard, Allentown, Pa. 18195-1501) and ammonia (G.S. Robbins and Company, 126 Chateau Avenue, St. Louis, Mo. 63102). The lacquer produced as described above may also contain a wax emulsion in water, such as Liquitron 440 (Carrol Scientific, Inc., 5401 S. Dansher Road, Countryside, Ill. 60525).
[0023] As stated above, the bonding material 58 may be an adhesive, such as a pressure sensitive adhesive, or a cohesive. Where the bonding material 58 is a cohesive, a similar cohesive material must be placed on both surfaces which are to be bonded together. As stated above, the bonding material 58 may be heat sealable and in this instance, the adjacent portions of the materials must be brought into contact and then heat must be applied to affect the seal. The lacquers described above are but one type of the bonding material 58 which is heat sealable. The bonding material 58 may also be a material which is sonic sealable and vibratory sealable. In the case of one type of heat sealable lacquer, the heat sealable lacquer may be applied to a sheet of material 5 and then heat, sound waves, or vibrations are then applied to effect the sealing.
[0024] The term “bonding material” also includes any heat or chemically shrinkable material, static, electrical or other electrical, magnetic, mechanical or barb-type fastening or clamps, curl-type characteristics of the film and the materials in a sheet of material which cause the sheet of material to take on certain shapes, and any type of welding method which may weld the sheet of material into an articulated bag.
[0025] The sheet of material 5 may further include at least one scent, the bonding material 58 may also include a scent, or both the sheet of material 5 and the bonding material 58 may include a scent. The scent may be incorporated into the structure of the sheet of material 5 during the fabrication of the sheet of material 5 or may be applied to the sheet of material 5 after it has been manufactured and before the sheet of material 5 is articulated into the bag of the present invention, such as bag 10 (FIG. 2). The scent may also be applied to the bag 10 of the present invention after it has been articulated from the sheet of material 5 . Examples of scents utilized herein include floral scents (flower blossoms or other portions of plants), food scents (chocolate, sugar, fruits), herb or spice scents (cinnamon), and the like. Additional examples of scents include flowers (i.e. roses, daisies, lilacs), plants (i.e. fruits, vegetables, grasses, and trees), foods (i.e. candies, cookies, cake), food condiments (i.e. honey, sugar, salt), herbs, spices, woods, roots, and the like, or any combinations of the foregoing. Such scents are known in the art and commercially available.
[0026] The scent may be applied to the sheet of material 5 by spraying the scent thereon, painting the scent thereon, brushing the scent thereon, lacquering the scent thereon, immersing sheet of material the 5 in a scent-containing liquid, exposing the sheet of material 5 to the scent containing gas or any combination thereof. The scent may also be incorporated onto the sheet of material 5 during the manufacture, extrusion, and/or lamination of the sheet of material 5 .
[0027] When articulated, the sheet of material 5 forms a generally tubular sheath, indicated by reference numeral 60 shown in FIG. 2. The tubular sheath 60 is provided with an interior surface 70 , an exterior surface 80 , a end top 90 , and a bottom end 100 . The tubular sheath 60 is articulated from the sheet of material 5 by folding the sheet of material 5 over and onto itself such that the first edge portion 40 of the sheet of material 5 is substantially adjacent the second edge portion 50 thereof. As shown in FIG. 2, where the first edge portion 40 is adjacent the second edge portion 50 , a first area of engagement 120 is defined. When the sheet of material 5 is folded over and onto itself, the third edge portion 55 folds over and onto itself as well, thereby defining a second area of engagement 130 . The first area of engagement 120 is exaggerated in size in FIG. 2 for purpose of description and it should be appreciated that the first area of engagement 120 , in practice, may be substantially smaller and less noticeable. The first area of engagement 120 is generally shaped and sized as a fin seal—i.e., the first edge portion 40 is directly adjacent and in alignment with the second edge portion 50 . The first area of engagement 120 also has an amount of the bonding material 58 disposed between the first edge portion 40 and the second edge portion 50 of the sheet of material 5 for affecting a seal therebetween. When sealed in this manner, the sheet of material 5 is articulated into the tubular sheath 60 having a fin seal seam, defined generally by the first area of engagement 120 .
[0028] As stated above, the second area of engagement 130 is created by the third edge portion 55 being folded over onto itself. Through the creation of the second area of engagement 130 , the bottom end 100 of the tubular sheath 60 is generally flattened. An amount of the bonding material 58 , which is disposed on the third edge portion 55 , is thus operably interspersed in the second area of engagement 130 such that the bottom end 100 is substantially closed. In the embodiment shown in FIG. 2, the bottom end 100 is sealed in a fin seal manner generally along the second area of engagement 130 .
[0029] Thus, as shown in FIG. 2, when the first and second areas of engagement 120 , 130 have been articulated and bondingly sealed, the bag 10 is formed. The bag 10 defines an interior retaining space 140 which is suitable for holding and retaining an item, such as a floral grouping or a corsage. Thus, the top end 90 of the bag 10 is in a substantially open and unobstructed configuration prior to an item being placed in the interior retaining space 140 of the bag 10 and the top end 90 coordinates with the interior retaining space 140 to provide egress to the interior retaining space 140 . After an item is placed in the interior retaining space 140 , the top end 90 may be crimped, folded, stapled, glued and/or mechanically closed in any manner whatsoever which allows for the retention of the item within the interior retaining space 140 of the bag 10 .
[0030] In an alternative embodiment of the invention, shown in FIGS. 3 and 4, a bag 10 A (FIG. 4) is formed from a sheet of material 5 A (FIG. 3) having a first surface 30 A and a second surface 150 . The first surface 30 A includes a first edge portion 40 A and a second edge portion 50 A. The second surface 150 includes a third edge portion 55 A. The third edge portion 55 A does not extend the entire length of an outside edge 160 located on the second surface 150 of the sheet of material 5 A: rather, the third edge portion 55 A extends generally to a midpoint 165 of the sheet of material 5 A, with the midpoint 165 being indicated generally by a dashed line shown in FIG. 3. A bonding material 58 A is disposed on at least a portion of the first, second, and third edge portions 40 A, 50 A, and 55 A, respectively. Thus, the first, second, and third edge portions 40 A, 50 A, and 55 A, respectively, define areas of adhesion 57 A. The remaining portion of the sheet of material 5 A which is free of adhesive defines a substantially open area 59 A which does not have the bonding material 58 A thereon.
[0031] Still referring to FIG. 4, when articulated, the sheet of material 5 A forms a generally tubular sheath 60 A, having an interior surface 70 A, an exterior surface 80 A, a top end 90 A, and a bottom end 100 A. The tubular sheath 60 A is articulated from the sheet of material 5 A by folding the sheet of material 5 A over and onto itself such that the first edge portion 40 A is substantially adjacent the second edge portion 50 A. The sheet of material 5 A is folded generally along the midpoint 165 when forming the tubular sheath 60 A.
[0032] As shown in FIG. 4, when the bag 10 A is articulated, i.e. where the first edge portion 40 A is adjacent the second edge portion 50 A, a first area of engagement 120 A is generally defined. Also, when the bag 10 A is articulated, the third edge portion 55 A is folded up toward the top end 90 A such that the third edge portion 55 A bondingly engages the exterior surface 80 A of the tubular sheath 60 A, and thereby defines a second area of engagement 130 A. In the embodiment shown in FIGS. 3 and 4, the first area of engagement 120 A is generally sized and shaped as a fin seal—i.e. the first edge portion 40 A is adjacent the second edge portion 50 A. The bonding material 58 A is located between the first edge portion 40 A and the second edge portion 50 A of the sheet of material 5 A such that first and second edge portions 40 A and 50 A are bondingly connected to one another so as to form the fin seal where the fin seal is generally defined by the first area of engagement 120 A.
[0033] The second area of engagement 130 A is generally characterized as being defined by a lap seal, i.e., the third edge portion 55 A is folded up toward the top end 90 A such that the third edge portion 55 A bondingly engages the exterior surface 80 A of the tubular sheath 60 A. By creating this lap seal at the second area of engagement 130 A, the bottom end 100 A is substantially flattened and closed, thereby providing the tubular sheath 60 A having two sealed areas of engagement 120 A, 130 A, respectively, and the substantially open top end 90 A.
[0034] Thus, as shown in FIG. 4, when the first and second areas of engagement 120 A, 130 A have been articulated and bondingly sealed the bag 10 A is formed. The bag 10 A has an interior retaining space 140 A which is suitable for holding and retaining an item, such as a floral grouping or a corsage. The top end 90 A is in a substantially open and unobstructed configuration prior to an item being placed within the interior retaining space 140 A. After an item is placed in the interior retaining space 140 A, the top end 90 A may be crimped, folded, stapled, and/or mechanically closed in any manner whatsoever which allows for the retention of the item in the interior retaining space 140 A.
[0035] In another embodiment of the present invention, shown in FIGS. 5 and 6, a bag 10 B (FIG. 6) is formed from a sheet of material 5 B. The sheet of material 5 B has a first surface 30 B and a second surface 150 B. The first surface 30 B includes a first edge portion 40 B and a second edge portion 50 B. The second surface 150 B includes a third edge portion 55 B. A bonding material 58 B is disposed on at least a portion of the first edge portion 40 B, the second edge portion 50 B, as well as on the third edge portion 55 B. Thus, the first, second and third edge portions 40 B, 50 B, 55 B, respectively, define areas of adhesion 57 B. The remaining portion of the sheet of material 5 B which is free of adhesive defines a substantially open area 59 B which does not have the bonding material 58 B thereon.
[0036] When articulated, the sheet of material 5 B forms a generally tubular sheath 60 B. The tubular sheath 60 B further includes an interior surface 70 B, an exterior surface 80 B, a top end 90 B, and a bottom end 100 B.
[0037] The tubular sheath 60 B is articulated from the sheet of material 5 B by folding the sheet of material 5 B over and onto itself such that the second edge portion 50 B overlaps and is substantially adjacent the third edge portion 55 B. As shown in FIG. 6, where the second edge portion 50 B overlaps the third edge portion 55 B, a first area of engagement 120 B is defined. When the sheet of material 5 B is folded, the first edge portion 40 B is folded onto itself and defines a second area of engagement 130 B.
[0038] The first area of engagement 120 B is generally sized and shaped as a lap seal, i.e., the third edge portion 55 B is adjacent the second edge portion 50 B. The first area of engagement 120 B also has an amount of the bonding material 58 B disposed between the third edge portion 55 B and the second edge portion 50 B. The bonding material 58 B holds and seals the second edge portion 50 B adjacent the third edge portion 55 B. When folded and sealed in this manner, the sheet of material 5 B is articulated into the tubular sheath 60 B having a lap-seal seam. This lap seal is defined generally by the first area of engagement 120 B.
[0039] As stated above, the second area of engagement 130 B is created by the first edge portion 40 B being folded over and onto itself. Through the articulation of the second area of engagement 130 B, the bottom end 100 B of the tubular sheath 60 B is generally flattened. The bonding material 58 B, which is disposed on the first edge portion 40 B, is thus operably interspersed within the second area of engagement 130 B such that the flattened bottom end 100 B of the tubular sheath 60 B is held and sealed by the bonding material 58 B. In the embodiment shown in FIG. 6, the bottom end 100 B of the tubular sheath 60 B is sealed in a fin seal manner generally along the second area of engagement 130 B.
[0040] Thus, as shown in FIG. 6, when the first and second areas of engagement 120 B and 130 B have been articulated and bondingly sealed, the bag 10 B is formed. The bag 10 B has an interior retaining space 140 B which is suitable for holding and retaining an item, such as a floral grouping or a corsage. The top end 90 B is in a substantially open and unobstructed configuration prior to an item being placed in the interior retaining space 140 B. After an item is placed in the interior retaining space 140 B, the top end 90 B may be crimped, folded, stapled, curved, and/or mechanically closed in any manner whatsoever which allows for the retention of the item within the interior retaining space 140 B.
[0041] In an additional embodiment of the present invention, shown in FIGS. 7 and 8, a bag 10 C is formed from a sheet of material 5 C. The sheet of material 5 C has a first surface 30 C and a second surface 150 C. The first surface 30 C includes a first edge portion 40 C. The second surface 150 C includes a second edge portion 50 C and a third edge portion 55 C. The third edge portion 55 C does not extend along the entire length of an outside edge 160 C of the second surface 150 C; rather, the third edge portion 55 C extends generally to a midpoint 165 C of the sheet of material 5 C, with the midpoint 165 C being indicated generally by a dashed line in FIG. 7.
[0042] A bonding material 58 C is applied to at least a portion of the first, second, and third edge portions 40 C, 50 C, and 55 C, respectively. Thus, the first, second and third edge portions 40 C, 50 C, and 55 C, respectively, define areas of adhesion 57 C. The remaining portion of the sheet of material 5 C which is free of adhesive defines a substantially open area 59 C which does not have the bonding material 58 C thereon.
[0043] When articulated, the sheet of material 5 C forms a generally tubular sheath 60 C, having an interior surface 70 C, an exterior surface 80 C, a top end 90 C, and a bottom end 100 C.
[0044] The tubular sheath 60 C is articulated from the sheet of material 5 C by folding the sheet of material 5 C over and onto itself such that the first edge portion 40 C overlaps and is substantially adjacent to the second edge portion 50 C. As shown in FIG. 8, where the first edge portion 40 C overlaps the second edge portion 50 C, a first area of engagement 120 C is defined. During folding, the third edge portion 55 C is folded over and onto itself defining a second area of engagement 130 C.
[0045] The first area of engagement 120 C is generally sized and shaped as a lap seal, i.e., the first edge portion 40 C is adjacent the second edge portion 50 C. The first area of engagement 120 C also has an amount of the bonding material 58 C disposed between the first edge portion 40 C and the second edge portion 50 C. The bonding material 58 C holds and seals the first edge portion 40 C adjacent the second edge portion 50 C. When folded and sealed in this manner, the sheet of material 5 C is articulated into the tubular sheath 60 C having a lap seal seam. This lap seal seam is defined generally by the first area of engagement 120 C.
[0046] The second area of engagement 130 C is generally formed into a lap seal, i.e., the third edge portion 55 C is folded up and bonded to the top end 90 C of the tubular sheath 60 C such that the third edge portion 55 C bondingly engages the exterior surface 80 C of the tubular sheath 60 C. By creating this lap seal at the second area of engagement 130 C, the bottom end 100 C of the tubular sheath 60 C is substantially flattened, closed, and sealed by the bonding material 58 C disposed on the third edge portion 55 C. The tubular sheath 60 C is thereby provided having the two sealed first and second areas of engagement 120 C, 130 C and the substantially open top end 90 C.
[0047] Thus, as shown in FIG. 8, when the first and second areas of engagement 120 C, 130 C have been articulated and bonded, the bag 10 C is formed. The bag 10 C has an interior retaining space 140 C which is suitable for holding and retaining an item, such as a floral grouping or a corsage. The top end 90 C is in a substantially open and unobstructed configuration prior to an item being placed in the interior retaining space 140 C. After an item is placed in the interior retaining space 140 C, the top end 90 C may be crimped, folded, stapled, and/or mechanically closed in any manner whatsoever which allows for the retention of the item in the interior retaining space 140 C.
[0048] Thus it should be apparent that there has been provided in accordance with the present invention a bag that fully satisfies the objectives and advantages set forth above. Although the 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, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. | A bag capable of displaying and protecting an item during shipping, transportation, handling and/or display. The bag is fabricated from at least one sheet of material which is formed into a tubular sheath having a heat-sealable bonding material disposed solely on portions of the tubular sheath of material so as to bondingly hold the tubular sheath of material in a bag-like configuration. The portions of the tubular sheath having the heat-sealable bonding material thereon may be configured as either lap or fin seals or combinations thereof. There is also provided methods for producing such a bag and methods for its use. | 1 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This application is a U.S. National Phase Application under 35 U.S.C. §371 of International Patent Application No. PCT/CN2010/071606, filed Apr. 7, 2010, and claims the benefit of Chinese Patent Application No. 200910188570.7, filed Nov. 28, 2009, and Chinese Patent Application No. 201010116533.8, filed Jan. 26, 2010, all of which are incorporated by reference herein. The International Application was published in Chinese on Jun. 3, 2011 as International Publication No. WO/2010/074115 under PCT Article 21(2).
FIELD OF THE INVENTION
The present invention relates to the field of organic synthesis, and more specifically to an antimicrobial compound and preparation thereof.
BACKGROUND OF THE INVENTION
Bacterial or fungal infection has become a worldwide important topic which poses a threat to human health and is given much attention in global medical and health services. It is one of important tools for dealing with bacterial or fungal infection to confer a material or article surface with antimicrobial property to prevent bacterial or fungal growth or multiplication thereon, even to kill bacteria or fungi on the surface. Now, internationally, antimicrobial materials can be divided into four main classes: (1) inorganic antimicrobial agents, for example, nano titanium dioxide, nano silver, nano copper, and their ions; (2) organic antimicrobial agents, for example, quaternary ammonium salts, thiazoles; (3) macromolecular antimicrobial agents, for example, macromolecular quaternary ammonium salts; and (4) natural antimicrobial agents and modifications thereof, for example, chitosan, sorbic acid.
It is the most common for conferring a material or article surface with antimicrobial property to apply a coating containing an antimicrobial agent (for example, nano silver, nano copper and their ions, or others) on the surface. The bacteriostasis or bactericidal effects of nano silver, nano copper, and other heavy metals and their ions are achieved by means of slow release of their metal ions into the environment. However, with usage time increasing, the antimicrobial activity of these materials gradually decreases, until it is eventually lost completely. In addition, microbial variation may be induced, resulting in an increase in the probability of drug resistance. Moreover, the harmfulness of nanomaterials is gradually being recognized and concerned. Organic antimicrobial agents and natural antimicrobial agents have poor heat resistance, which often limits their use ranges. Macromolecular quaternary ammonium salt antimicrobial agents are focused because they can overcome the shortcomings such as high volatility, difficulty in processing, and poor chemical stability of micromolecular antimicrobial agents, have excellent antimicrobial activity, and do not easily permeate into the human skin. For example, Ruowen Fu group [Reactive & functional polymers, 2007, 67:355-366] prepared a series of macromolecular quaternary ammonium salts of methacrylates as antimicrobial agent, having minimum inhibitory concentration(MIC) of 1.56-20 mg/mL. The polymeric antimicrobial agents are also mainly polymeric quaternary ammonium salts and polymeric haloamines, which have undesirable thermal stability. Moreover, in order to obtain a good antimicrobial agent, it is usually required that the antimicrobial agent is water-soluble. So, there is loss in these non-immobilized macromolecular antimicrobial agents, resulting in lack of durability in antimicrobial activity, and also putting a burden on the environment. For example, Lowe et al. [J. Appl. Polym. Sci., 2006, 101:1036-1041] prepared a series of polymeric betaine antimicrobial agents, having minimum inhibitory concentration (MIC) of 1125-2000 ug/mL, which provides a new thought to develop antimicrobial agents. But, they have no reactive functional group that can be immobilized, so that the disadvantage of loss due to release cannot be avoided.
The antimicrobial agent with such release property has at least two adverse factors: (1) the implanted antimicrobial agent has time-dependant release and is lack of persistent antimicrobial activity; (2) the released antimicrobial agent puts a burden on the environment. These factors cannot be neglected and it is inevitable to develop and prepare a green non-released antimicrobial agent. Immobilizing a group with antimicrobial activity onto a material or article surface through chemical bonding can confer the material or article with persistent antimicrobial activity, and also, would not cause contamination on the environment. Madkour [Langmuir, 2009, 25: 1060-1067] prepared a coating with rapid antimicrobial property by reacting a halogen-containing silane with a hydroxyl-containing surface and further employing atom transfer radical polymerization. However, this method has a complicated process and harsh conditions, and is difficult to be industrialized. Saif [Langmuir, 2009, 25:377-379] prepared an organosilicon quaternary ammonium salt antimicrobial agent having persistent antimicrobial activity, and DC-5700 early developed by DOW Corning also belongs to this class. But, the quaternary ammonium salt antimicrobial agent has poor heat resistance, limiting its use range.
It is a new requirement in the development of human society to research and develop a new class of durable antimicrobial agent that can be immobilized, by overcoming the disadvantages present in the field of current antimicrobial agents as described above.
SUMMARY OF THE INVENTION
One object of the present invention is to provide an antimicrobial compound, which can be tenaciously bonded to many material or product interfaces with a reactive function group (siloxane group) via chemical bonding made to generate persistent antimicrobial activity and hydrophilicity.
The organosilicon betaine type antimicrobial compound provided by the present invention has a general formula I:
in which, R 0 ═H, R 3 X;
R 1 is selected from —CH 3 or —CH 2 CH 3 ; R 2 is selected from —OR 1 , —CH 3 , or —CH 2 CH 3 ; R 3 is selected from —(CH 2 ) m NH(CH 2 ) n , where m, n=1-6, or —(CH 2 ) p , where p=1-10; R 4 is —(CH 2 ) q CH 3 , where q=0-17, or R 4 ═H; R 5 is —(CH 2 ) q CH 3 , where q=0-17, or R 5 ═H; R 6 is selected from —(CH 2 ) r NH(CH 2 ) t , where r, t=1-10, or —(CH 2 ) u , where u=1-6; Y is selected from —COO, or —SO 3 .
In the general formula I, the substituents R 4 and R 5 are the same or different.
Another object of the present invention is to provide a method of preparing the antimicrobial compound, which has a simple synthesis process, easily controlled conditions, a high yield, and is easy to be industrialized.
This subject is achieved by a method of preparing the antimicrobial compound comprising the steps of:
preparing a tertiary amine-containing organic siloxane and continuously reacting the tertiary amine-containing organic siloxane with a reactant B by keeping in an environment at 10-80° C. with stirring for 1-48 h, to yield a white precipitate; filtering or isolating by centrifugation the white precipitate, to yield an organosilicon betaine type antimicrobial compound, i.e. target product; The reactant B is one selected from propane sultone, butane sultone, acrylic acid, β-propiolactone, X(CH 2 ) v SO 3 − , or X(CH 2 ) v CO 2 − , where X is Br, Cl or I, v is a positive integer greater than or equal to 1.
A typical synthetic route of the preparation method above is:
In the preparation steps above, the tertiary amine-containing organic siloxane is prepared by: reacting (R 1 O) 2 R 2 SiH with a reactant A by hydrosilylation at 10-80° C. in the presence of a platinum-based catalyst with stirring for 1-48 h; where R 1 is selected from —CH 3 or —CH 2 CH 3 , and R 2 is selected from —OR 1 , —CH 3 or —CH 2 CH 3 ; and the reactant A is a tertiary amine-containing alkene, preferably dimethylallylamine or diethylallylamine.
In the preparation steps above, the platinum-based catalyst is selected from chloroplatinic acid catalyst, SiO 2 supported platinum catalyst, activated carbon supported platinum catalyst, or Karstedt type platinum catalyst.
In the preparation steps above, the tertiary amine-containing organic siloxane can also be prepared by: reacting (R 1 O) 2 R 2 SiR 3 X and R 4 R 5 NH at 20-80° C. with a NaOH/isopropanol solution added as catalyst with stirring for 2-48 h; where R 1 is —CH 3 or —CH 2 CH 3 ; R 2 is —OR 1 , —CH 3 or —CH 2 CH 3 ; R 3 is selected from —(CH 2 ) p , where p=1-10; R 4 is —(CH 2 ) q CH 3 , where q=0-17; R 5 is —(CH 2 ) q CH 3 , where q=0-17; X is Br, Cl or I.
The present invention also provides another method of preparing the antimicrobial compound, comprising the step of: continuously reacting an amino-containing siloxane with a reactant B by keeping in an environment at 10-80° C. with stirring for 1-48 h to yield an organosilicon betaine type antimicrobial compound, i.e. target product.
Similarly, the reactant B is one selected from propane sultone, butane sultone, acrylic acid, β-propiolactone, X(CH 2 ) v SO 3 − , or X(CH 2 ) v CO 2 − , where X is Br, Cl or I, v is a positive integer greater than or equal to 1.
The advantages of the technical solutions above is in that the antimicrobial compound has a reactive functional group—siloxane, which can be subjected to chemical bonding with many material interfaces, thereby rendering a material or article surface treated with the antimicrobial compound persistent antimicrobial activity and stronger hydrophilicity. Also, the preparation method has a simple synthesis process and easily controlled conditions, and is easy to be industrialized, which facilitates its wide applications. In addition, the antimicrobial compound has unique advantages such as resistance to acids, alkalis and salts, especially low toxicity and good chemical stability and thermal stability, so that an article surface treated with the antimicrobial compound can be subjected to various common disinfection treatments.
DETAILED DESCRIPTION OF THE INVENTION
In order to make the above objects, technical solutions and advantages of the invention more apparent, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention and not to limit the present invention.
Embodiment 1
98.6 g triethoxysilane [(CH 3 CH 2 O) 3 SiH] was weighted and added to a round-bottomed flask with mechanical stirring and a reflux apparatus. After 0.2 ml of chloroplatinic acid/isopropanol catalyst was added, 51.2 g dimethylallylamine [CH 2 ═CHCH 2 N(CH 3 ) 2 ] was slowly added dropwise via a dropping funnel with stirring at 60° C. After the dropwise addition was completed, the reaction was continued for 1 h. The temperature was reduced to 50° C., and then 73.2 g propane sultone [
hereafter referred to simply as 1,3-PS] (dissolved in 400 mL absolute ethanol) was added dropwise. After the dropwise addition was completed, the reaction was continued for 1 h, to yield a white precipitate. The precipitate was isolated by centrifugation and purified several times, to yield an organosilicon-sulfonic acid type betaine antimicrobial agent, with the structural formula: (CH 3 CH 2 O) 3 Si(CH 2 ) 3 + N(CH 3 ) 2 (CH 2 ) 3 SO 3 − , and having a minimum inhibitory concentration (MIC) of 15 mg/mL and a minimum bactericidal concentration (MEC) of 20 mg/mL for both E. coli (8099) and S. aureas (ATCC6538).
Embodiment 2
107.8 g methyldiethoxysilane [(CH 3 CH 2 O) 2 CH 3 SiH] was weighted and added to a flat-bottomed flask with magnetic stirring and a reflux apparatus. After 0.25 g SiO 2 supported platinum-gold catalyst was added, 88.9 g diethylallylamine [CH═CHCH 2 N(CH 2 CH 3 ) 2 ] was slowly added dropwise via a dropping funnel with magnetic stirring at 30° C., and the reaction time was started. After 8 h of reaction, the catalyst was recovered by filtration under reduced pressure. Then, the filtrate was collected, to which 97.6 g 1,3-PS (dissolved in 400 mL absolute ethanol) was added dropwise. The reaction was continued at 30° C. for 10 h, to yield a white precipitate. The precipitate was filtered and purified by washing with ethanol several times, to yield an organosilicon-sulfonic acid type betaine antimicrobial agent, with the structural formula: (CH 3 CH 2 O) 2 SiCH 3 (CH 2 CH 3 ) 3 + N(CH 3 ) 2 (CH 2 ) 3 SO 3 − , and having a MIC of 25 mg/mL and a MBC of 30 mg/mL for both E. coli (8099) and S. aureas (ATCC6538).
Embodiment 3
107.6 g methyldiethoxysilane [(CH 3 CH 2 O) 2 CH 3 SiH] was weighted and added to a flat-bottomed flask with magnetic stirring and a reflux apparatus. After 0.20 g of Karstedt type platinum-gold catalyst was added, 68.2 g dimethylallylamine [CH 2 ═CHCH 2 N(CH 3 ) 2 ] was slowly added dropwise via a dropping funnel with magnetic stirring at 20° C., and the reaction time was started. After 24 h of reaction, the catalyst was recovered by filtration under reduced pressure. Then, the filtrate was collected, to which 93.2 g sodium chloroacetate [ClCH 2 CO 2 Na] (dissolved in 400 mL absolute ethanol) was added dropwise. The reaction was continued at 20° C. for 24 h, to yield a white precipitate. The precipitate was isolated by centrifugation and purified several times, to yield an organosilicon carboxylic acid type betaine antimicrobial agent, with the structural formula: (CH 3 CH 2 O) 2 SiCH 3 (CH 2 ) 3 + N(CH 3 ) 2 CH 2 CO 2 − , and having a MIC of 20 mg/mL and a MBC of 25 mg/mL for both E. coli (8099) and S. aureas (ATCC6538).
Embodiment 4
107.6 g methyldiethoxysilane [(CH 3 CH 2 O) 2 CH 3 SiH] was weighted and added to a round-bottomed flask with mechanical stirring and a reflux apparatus. After 0.20 g activated carbon supported platinum-gold catalyst was added, 68.2 g dimethylallylamine [CH 2 ═CHCH 2 N(CH 3 ) 2 ] was slowly added dropwise via a dropping funnel with stirring at 50° C. After the dropwise addition was completed, the reaction was continued for 2 h. The catalyst was recovered by filtration under reduced pressure. Then, the filtrate was collected, to which 57.7 g β-propiolactone
(dissolved in 400 mL butanone) was added dropwise. The reaction was continued for 6 h at 40° C., to yield a white precipitate. The precipitate was isolated by centrifugation and purified several times, to yield an organosilicon carboxylic acid type betaine antimicrobial agent, with the structural formula: (CH 3 CH 2 O) 2 SiCH 3 (CH 2 ) 3 + N(CH 3 ) 2 (CH 2 ) 2 CO 2 − , and having a MIC of 10 mg/mL and a MBC of 20 mg/mL for both E. coli (8099) and S. aureas (ATCC6538).
Embodiment 5
142.5 g N,N-diethyl-3-aminopropyltrimethoxysilane [(CH 3 CH 2 ) 2 N(CH 2 ) 3 Si(OCH 3 ) 3 ] was weighted and added to a flat-bottomed flask with magnetic stirring and a reflux apparatus. 73.2 g 1,3-PS (dissolved in 400 mL acetone) was slowly added dropwise with magnetic stirring. The reaction was continued for 48 h at 10° C., to yield a white precipitate. The precipitate was isolated by centrifugation and purified several times, to yield an organosilicon sulfonic acid type betaine antimicrobial agent, with the structural formula: (CH 3 O) 3 Si(CH 2 ) 3 + N(CH 2 CH 3 ) 2 (CH 2 ) 3 SO 3 − , and having a MIC of 15 mg/mL and a MBC of 20 mg/mL for both E. coli (8099) and S. aureas (ATCC6538).
Embodiment 6
97.8 g trimethoxysilane [HSi(OCH 3 ) 3 ] was weighted and added to a flat-bottomed flask with mechanical stirring and a reflux apparatus. After 0.20 g activated carbon supported platinum-gold catalyst was added, 88.9 g diethylallylamine [CH 2 ═CHCH 2 N(CH 2 CH 3 ) 2 ] was slowly added dropwise via a dropping funnel with magnetic stirring at 50° C. After the dropwise addition was completed, the reaction was continued for 2 h. The heating was stopped, and the catalyst was recovered by filtration under reduced pressure. Then, the filtrate was collected, to which 93.2 g ClCH 2 CH 2 SO 3 Na (dissolved in 400 mL absolute ethanol) was added dropwise. The mixture was heated to 50° C. and further reacted for 10 h, to yield a white precipitate. The precipitate was filtered and purified by washing with absolute ethanol several times, to yield an organosilicon sulfonic acid type betaine antimicrobial agent, with the structural formula: (CH 3 O) 3 Si(CH 2 ) 3 + N(CH 2 CH 3 ) 2 (CH 2 ) 2 SO 3 − , and having a MIC of 20 mg/mL and a MBC of 25 mg/mL for both E. coli (8099) and S. aureas (ATCC6538).
Embodiment 7
124.0 g N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane [NH 2 (CH 2 ) 2 NH(CH 2 ) 3 SiCH 3 (OCH 3 ) 2 ] was weighted and added to a flat-bottomed flask with a magnetic stirrer and a reflux apparatus. 73.2 g 1,3-PS (dissolved in 400 mL absolute ethanol) was slowly added dropwise with magnetic stirring. The mixture was heated to 40° C. and reacted for 2 h, to yield an organosilicon sulfonic acid type betaine antimicrobial agent as yellowish oil, with the structural formula: (CH 3 O) 3 Si(CH 2 ) 3 NH(CH 2 ) 2 + NH 2 (CH 2 ) 3 SO 3 − , and having a MIC of 25 mg/mL and a MEC of 30 mg/mL for both E. coli (8099) and S. aureas (ATCC6538).
Embodiment 8
119.2 g chloropropyltrimethoxysilane [(CH 3 O) 3 SiCH 2 CH 2 CH 2 Cl] was weighted and added to a round-bottomed flask with a mechanical stirrer and a reflux apparatus. 60.7 g di-n-propylamine [(CH 3 CH 2 CH 2 ) 2 NH] (dissolved in 200 ml absolute ethanol) was slowly added dropwise via a dropping funnel with stirring at 80° C. After the dropwise addition was completed, the reaction was continued for 10 h, and then the temperature was reduced to 30° C. 73.2 g 1,3-PS (dissolved in 200 mL absolute ethanol) was added dropwise. The reaction was continued for 10 h, to yield a white precipitate. The precipitate was isolated by centrifugation and purified several times, to yield an organosilicon sulfonic acid type betaine antimicrobial agent, with the structural formula: (CH 3 O) 3 Si(CH 2 ) 3 + N(CH 2 CH 2 CH 3 ) 2 (CH 2 ) 3 SO 3 − , and having a MIC of 15 mg/mL and a MBC of 20 mg/mL for both E. coli (8099) and S. aureas (ATCC6538).
The resulting products from the above examples were used for treating a glass surface respectively, a superhydrophilic surface at a contact angle of less than 10° C. was all obtained. In addition, they were tested for antimicrobial activity and persistent antimicrobial activity using the colony counting method, and the results are shown in table 1.
TABLE 1
Analysis of persistent antimicrobial activity of antimicrobial agents in
embodiments 1-8 (plate counting method)
Wash times
Sample
Strain
0
1
5
10
30
Embodiment
E. coli
99.9%
99.8%
99.5%
99.0%
99.2%
1
S. aureas
99.9%
99.9%
99.6%
99.5%
99.0%
Embodiment
E. coli
99.9%
99.9%
99.3%
98.9%
98.5%
2
S. aureas
99.9%
99.9%
99.9%
99.6%
99.0%
Embodiment
E. coli
99.9%
99.8%
99.2%
97.9%
97.2%
3
S. aureas
99.9%
99.9%
99.5%
98.2%
97.6%
Embodiment
E. coli
99.9%
99.8%
99.0%
98.6%
98.1%
4
S. aureas
99.9%
99.9%
99.6%
98.9%
98.3%
Embodiment
E. coli
99.9%
99.7%
99.0%
98.7%
98.0%
5
S. aureas
99.9%
99.9%
99.5%
98.8%
98.2%
Embodiment
E. coli
99.9%
99.8%
99.3%
97.9%
97.2%
6
S. aureas
99.9%
99.9%
99.5%
98.2%
97.6%
Embodiment
E. coli
99.9%
99.5%
99.1%
98.6%
98.0%
7
S. aureas
99.9%
99.8%
99.6%
99.1%
98.2%
Embodiment
E. coli
99.9%
99.7%
99.3%
98.7%
98.2%
8
S. aureas
99.9%
99.9%
99.5%
98.8%
98.5%
In other preferred embodiments of the present invention, an equivalent amount of substance of CH 3 CH 2 (CH 3 O) 2 SiH, CH 3 CH 2 (CH 3 CH 2 O) 2 SiH, CH 3 (CH 3 O) 2 SiH can be selected in place of (CH 3 CH 2 O) 3 SiH or (CH 3 O) 3 SiH or (CH 3 CH 2 O) 2 CH 3 SiH; also, an equivalent amount of substance of butane sultone, acrylic acid, X(CH 2 ) v SO 3 Na, or X(CH 2 ) v CO 2 Na (where X is Br, Cl or I; v is a positive integer greater than or equal to 1) can be selected in place of propane sultone, β-propiolactone, ClCH 2 CO 2 Na, or ClCH 2 CH 2 SO 3 Na.
The descriptions above are only several embodiments of the present invention, which are described specifically and in detail, and therefore, these cannot be construed as limiting the scope of the present invention. It should be noted that other many modifications and improvements can be made by one skilled in the art, without departing from the concept of the present invention, and such modifications and improvements fall into the scope of the present invention. | The present invention relates to the field of organic synthesis, and provides an organosilicon betaine type antimicrobial compound having a general formula I and preparation thereof:
the antimicrobial compound provided by the present invention has a reactive functional group—siloxane, which can be subjected to chemical bonding with many material interfaces, thereby endowing a material or article surface treated with the antimicrobial compound I persistent antimicrobial activity. Also, the preparation of the compound has a simple process and easily controlled conditions, and is easy to be industrialized, which facilitates its wide applications. | 2 |
CLAIM OF PRIORITY
[0001] This application claims priority to an application entitled “L-Band Light Source with Improved Amplifying Efficiency and Stabilized Output Power,” filed with the Korean Intellectual Property Office on Dec. 19, 2003 and assigned Ser. No. 2003-93866, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an optical module, in particular to an L-band light source.
[0004] 2. Description of the Related Art
[0005] A light source with a wide wavelength band is needed to measure the optical characteristics employed in optical communication. Moreover, the wavelength band of the optical signals used in optical communication is 1520 nm˜1620 nm when at least one erbium doped fiber amplifier (EDFA) is employed. Thus, a light source capable of measuring optical characteristics of various optical components within such a wavelength band is needed.
[0006] A wavelength division multiplexing passive optical network (WDM-PON) has recently been highlighted as a technology for a high-speed fiber-to-the-home (FTTH) network. In a WDM-PON attention is paid to the broadband light source that is used along with a wavelength locked Fabry Perot laser diode (FP-LD) in order to accommodate a plurality of subscribers. Existing available broadband light sources mainly employ a white light source or an EDFA outputting amplified spontaneous emission (ASE). However, because white light sources have low output power, they are limited in measuring the optical characteristics of a light source or an optical component for a WDM-PON which requires high output power. In addition, EDFAs are not economical in price.
[0007] U.S. Pat. No. 6,507,429 issued to Gaelle Ales et al. and entitled “Article Comprising a High Power/Broad Spectrum Superfluorescent Fiber Radiation Source” discloses a broadband source for outputting C-band (1520 nm˜1570 nm) ASE and L-band (1570 nm˜1620 nm) ASE. The broadband light source includes first and second rare earth element doped optical fibers, and an isolator located between the optical fibers. First pumping light from a first pump light source is supplied to the first rare earth element doped optical fiber and second pumping light from second pump light source is supplied to the second rare earth element doped optical fiber. The first rare earth element doped optical fiber has a length longer than that of the second rare earth element doped optical fiber about five times. A reflector reflects ASE inputted from the first rare earth element doped optical fiber, thus assisting generation of L-band ASE in the first rare earth element doped optical fiber. The second rare earth element doped optical fiber conducts functions of amplifying the L-band ASE and generating C-band ASE. As a result, the broadband light source is able to output C-band and L-band ASEs through an output end thereof.
[0008] However, the typical broadband optical source has poor output efficiency. This is due to the isolator being between the first and second rare earth element doped optical fibers; thus, the C-band ASE outputted to the rear side of the second rare earth element doped optical fiber cannot be used. In addition, if the output power of the first pump light source is changed so as to tune the output power of the L-band ASE (obtained from the first rare earth element doped optical fiber), not only the output power of the L-band ASE but also the output power of the C-band ASE is changed. In contrast, if the output power of the second pump light source is changed so as to tune the C-band ASE (obtained from the second rare earth element doped optical fiber), not only the output power of the C-band ASE, but also the output power of the L-band ASE is changed. Accordingly, since the output powers of the C-band ASE and L-band ASE are affected by one another, it is more difficult to control the output power of the broadband light source.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention has been made to reduce or overcome the above-mentioned problems occurring in the prior art. One object of the present invention is to provide an L-band light source having improved amplifying efficiency and stabilized output power. Thus, the L-band light source is suitable for measuring the characteristics of an optical component or use as a broadband light source for a WDM-PON.
[0010] In accordance with the principles of the present invention, an L-band light source is provided and includes: a gain medium having first and second sides, and configured to generate an L-band amplified spontaneous emission (ASE); a first pump light source to generate first pumping light; a first wavelength selective coupler to supply the first pumping light to the gain medium; and a first reflector to reflect a part of ASE outputted to the fist side of the gain medium, the first reflector having a predetermined reflection wavelength included in C-band.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0012] FIG. 1 shows a construction of an L-band light source according to a first embodiment of the present invention;
[0013] FIG. 2 shows a construction of an L-band light source according to a second embodiment of the present invention;
[0014] FIG. 3 shows a construction of an L-band light source according to a third embodiment of the present invention; and
[0015] FIG. 4 is a view for illustrating characteristics of output power of the broadband light source shown in FIG. 1 .
DETAILED DESCRIPTION
[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. For the purposes of clarity and simplicity, a detailed description of known functions and configurations incorporated herein will be omitted as it may make the subject matter of the present invention unclear.
[0017] FIG. 1 shows a construction of an L-band light source according to a first embodiment of the present invention. The L-band light source 100 comprises a fiber Bragg grating (FBG) 120 , first and second pump light sources 130 , 135 , first and second wavelength selective couplers (WSCs) 140 , 145 , a gain medium 150 , and an isolator (ISO) 160 . The fiber Bragg grating 120 , the gain medium 150 , the first and second wavelength selective couplers 140 , 145 and the isolator 160 are connected in series using a first optical waveguide 110 . The first pump light source 130 is connected in parallel to the gain medium 150 using a second optical waveguide 112 and the second pump light source 135 is connected in parallel to the gain medium 150 using a third optical waveguide 114 .
[0018] The first pump light source 130 outputs first pumping light, and the first and second pump light sources 130 , 145 may each incorporate a laser diode outputting light having a wavelength of 980 nm or 1480 nm.
[0019] The first wavelength selective coupler 140 is located between the fiber Bragg grating 120 and the gain medium 150 . The first wavelength selective coupler 140 supplies pumping light to the gain medium 150 .
[0020] The second pump light source 125 outputs second pumping light. The second wavelength selective coupler 145 is located between the gain medium 150 and the isolator 160 . The second wavelength selective coupler 145 supplies the second pumping light to the gain medium 150 .
[0021] The gain medium 150 is located between the first and second wavelength selective couplers 140 , 145 and has a length suitable for generating L-band ASE. The gain medium 150 is controlled to have a relatively long length. Thus, it generates ASE in a wavelength band of 1520 nm˜1620 nm. In addition, the C-band (1520 nm˜1570 nm) ASE in the generated ASE is absorbed while progressing within the gain medium 150 . As a result, the gain medium 150 serves to amplify the L-band (1570 nm˜ASE 1620 nm) with a lower output power generated at the end of the gain medium 150 . For example, the gain medium 150 may incorporate an EDF having a length of about 50 m. The gain medium 150 outputs ASE to a first and second side, hereinafter, front and rear sides, thereof as it is pumped by the first and second pumping light. The ASE outputted to the front side of the gain medium 150 passes the second wavelength selective coupler 145 and the isolator 160 . Then the ASE is outputted to the outside through the output end 104 of the L-band light source 100 . The ASE outputted to the rear side of the gain medium 150 passes the first wavelength selective coupler 140 . Then, the ASE is inputted into the fiber Bragg grating 120 .
[0022] The fiber Bragg grating 120 is located between a terminal end 102 of the L-band light source 100 and the first wavelength selective coupler 140 . The fiber Bragg grating 120 has a predetermined reflection wavelength and reflects a part of the inputted rear side ASE to the gain medium 150 . The rear side ASE reflected from the fiber Bragg grating 120 passes the first wavelength selective coupler 140 . Then, the rear side ASE is inputted into the gain medium 150 , thus pumping the gain medium 150 . The ASE having passed the fiber Bragg grating 120 is inputted into the terminal end of the L-band light source 100 and disappears. The fiber Bragg grating 120 may have a reflection wavelength of 1560 nm.
[0023] In order to prevent the rear side ASE reflected from the terminal end 102 of the broadband light source 100 from being inputted into the first wavelength selective coupler 140 , an angled connector may be provided at the terminal end 102 of the broadband light source 100 . Alternatively, an additional isolator may be installed between the terminal end 102 and the fiber Bragg grating 120 . It is also possible to form a reflecting body which reflects about 4% of the rear side ASE. This can be accomplished by cutting an end surface of the first optical waveguide 110 vertically to the progressing direction of the rear side ASE, whereby the reflected C-band ASE can improve the output power of the L-band ASE.
[0024] The isolator 160 is located between the gain medium 150 and the output end 104 of the broadband light source 100 . The isolator 160 passes the front side ASE inputted from the gain medium 150 and blocks light progressing in the opposite direction.
[0025] FIG. 4 is a view for illustrating output characteristics of the broadband light source shown in FIG. 1 . FIG. 4 shows output spectrum 430 of the broadband light source 100 and output spectrum 430 obtained after removing the fiber Bragg grating 120 from the broadband light source 100 . The fiber Bragg grating 120 has a wavelength of 1560 nm, and the reflected spectrum 410 of the fiber Bragg grating 120 is shown in the drawing. It can be seen that the L-band ASE is efficiently amplified after the gain medium 150 is pumped with reflected light having a wavelength of 1560 nm. At this time, the amplified intensity of L-band ASE may be varied depending on the power of the reflected light. If the power of the reflected light is too high, the reflected light takes the energy of the L-band ASE and the reflected light may be amplified whereas the power of the L-band ASE may decrease. As a result, the gain medium 150 may be placed in a saturated condition in a predetermined power range.
[0026] FIG. 2 shows a construction of an L-band light source according to a second embodiment of the present invention. The L-band light source 200 comprises first and second fiber Bragg gratings 220 , 225 , first and second pump light sources 230 , 235 , first and second wavelength selective couplers 240 , 245 , a gain medium 250 , and an isolator 260 .
[0027] The first pump light source 230 outputs first pumping light. The first wavelength selective coupler 240 is located between the first fiber Bragg grating 220 and the gain medium 250 . The first wavelength selective coupler 240 supplies the first pumping light to the gain medium 250 .
[0028] The second pump light source 235 outputs second pumping light. The second wavelength selective coupler 245 is located between the gain medium 250 and the second fiber Bragg grating 225 . The second wavelength selective coupler 245 supplies the second pumping light to the gain medium 250 .
[0029] The gain medium 250 is located between the first and second wavelength selective couplers 240 , 245 and has a length suitable for generating L-band ASE. The gain medium 250 outputs ASE to the front and rear sides thereof as it is pumped by the first and second pumping light. The ASE outputted to the front side of the gain medium 250 passes the second wavelength selective coupler 245 . Then, the ASE is inputted into the second fiber Bragg grating 225 . The ASE outputted to the rear side of the gain medium 250 passes the first wavelength selective coupler 240 . Then, the ASE is inputted into the first fiber Bragg grating 220 .
[0030] The first fiber Bragg grating 220 is located between a terminal end 202 of the L-band light source 200 and the first wavelength selective coupler 140 . The first fiber Bragg grating 220 has a predetermined reflection wavelength and reflects a part of the inputted rear side ASE toward the gain medium 250 . The rear side ASE reflected from the first fiber Bragg grating 220 passes the first wavelength selective coupler 240 . Then, the rear side ASE is inputted into the gain medium 250 , thus pumping the gain medium 250 . The rear side ASE having passed the first fiber Bragg grating 220 is inputted into the terminal end 202 of the L-band light source 200 and disappears. The first fiber Bragg grating 220 may have a reflection wavelength of 1560 nm.
[0031] The second fiber Bragg grating 225 is located between the second wavelength selective coupler 245 and the isolator 160 and has a predetermined reflection wavelength included in the C-band. The second fiber Bragg grating 225 reflects a part of the inputted front side ASE toward the gain medium 250 . The front side ASE reflected from the second fiber Bragg grating 225 passes the second wavelength selective coupler 245 . Then the front side ASE is inputted into the gain medium 250 , thus pumping the gain medium 250 . The ASE having passed the second fiber Bragg grating 225 passes the isolator 260 and then the ASE is outputted to the outside through the output end 204 of the L-band light source 200 . The second fiber Bragg grating 225 may have a wavelength of 1550 nm. If the reflection wavelengths of the first and second fiber Bragg gratings 220 , 225 are the same as one another and the reflected ASEs are not sufficiently absorbed within the gain medium 250 , they may form a resonance structure and cause oscillation. Therefore, it is possible to make the first and second fiber Bragg gratings 220 , 225 have different wavelengths.
[0032] The isolator 260 is located between the second fiber Bragg grating 225 and the output end 204 of the broadband light source 200 . The isolator 260 passes the front side ASE having passed the second fiber Bragg grating 225 and blocks light progressing in the opposite direction.
[0033] FIG. 3 shows a construction of an L-band light source according to a third embodiment of the present invention. The L-band light source 300 comprises a reflector 320 , a fiber Bragg grating 360 , first and second pump light sources 330 , 335 , first and second wavelength selective couplers 340 , 345 , a gain medium 350 , and an isolator 370 .
[0034] The first pump light source 330 outputs first pumping light. The first wavelength selective coupler 340 is located between the reflector 320 and the gain medium 350 . The first wavelength selective coupler 340 supplies the first pumping light to the gain medium 350 .
[0035] The second pump light source 335 outputs second pumping light. The second wavelength selective coupler 345 is located between the gain medium 350 and the fiber Bragg grating 360 . The second wavelength selective coupler 345 supplies the second pumping light to the gain medium 350 .
[0036] The gain medium 350 is located between the first and second wavelength selective couplers 340 , 345 and has a length suitable for generating L-band ASE. The gain medium 350 outputs the ASE to the front and rear sides thereof as it is pumped by the first and second pumping light. The ASE outputted to the front side of the gain medium 350 passes the second wavelength selective coupler 345 . Then, the ASE is inputted into the fiber Bragg grating 360 . The ASE outputted to the rear side of the gain medium 350 passes the first wavelength selective coupler 340 . Then, the ASE is inputted into the fiber Bragg grating 360 .
[0037] The reflector 320 is provided at a terminal end of the L-band light source 300 . The reflector 320 reflects the inputted rear side ASE toward the gain medium 350 . The ASE reflected from the reflector 320 passes the first wavelength selective coupler 340 . Then the ASE is inputted into the gain medium 350 , thus pumping the gain medium 350 .
[0038] The fiber Bragg grating 360 is located between the second wavelength selective coupler 345 and the isolator 370 and has a predetermined reflection wavelength included in C-band. The fiber Bragg grating 360 reflects a part of the inputted front side ASE toward the gain medium 350 . The ASE reflected from the second fiber Bragg grating 360 passes the second wavelength selective coupler 345 . Then, the front side ASE is inputted into the gain medium 350 , thus pumping the gain medium 350 . The ASE having passed the fiber Bragg grating 360 passes the isolator 370 . Then, the ASE is outputted to the outside through the output end 304 of the L-band light source 300 .
[0039] The isolator 370 located between the fiber Bragg grating 360 and the output end 304 of the broadband light source 300 . The isolator 370 passes the front side ASE having passed the fiber Bragg grating 360 and blocks light progressing in the opposite direction.
[0040] Advantageously, an L-band light source according to the present invention reuses a part of ASE generated in a gain medium as pumping light by employing a fiber Bragg grating.
[0041] Accordingly, amplifying efficiency is increased and output power is stabilized. The present invention also enables fabrication of (1) an expanded broadband light source and (2) a light source for measuring an optical characteristic of an optical component, needed in a wavelength division multiplexing passive optical network to be developed in earnest in the future.
[0042] While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | An L-band light source is provided that has improved amplifying efficiency and stabilized output power. The L-band light source comprises: a gain medium having first and second sides, and configured to generate an L-band amplified spontaneous emission (ASE); a first pump light source to generate first pumping light; a first wavelength selective coupler to supply the first pumping light to the gain medium; and a first reflector to reflect a part of ASE outputted to the fist side of the gain medium, the first reflector having a predetermined reflection. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 13/764,994, filed Feb. 12, 2013, which claims the benefit of U.S. Provisional Application Ser. No. 61/598,558, filed Feb. 14, 2012, both applications being herein incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to improvements for golf course bunkers and, more particularly, to the creation and utilization of modular, porous bunker paver blocks to improve the longevity and appearance of sand bunkers.
BACKGROUND OF THE INVENTION
[0003] The golf course bunker originated in Scotland and Ireland as a hazard on the golf course (other hazards including rough areas, water, mounds, trees and the like), where these hazards are included in a golf course design as obstacles for strategy and direction, as well as for aesthetic purposes. In its earliest form, the bunker was more of a natural sand pit and was not formally maintained. In time, design styles changed and the bunker became a formalized tool that was utilized by course designers to create unique challenges for golfers. Indeed, most of the great, well-known golf courses include dramatic bunkers, where their styles vary from steep slopes with sand or turf to expansive areas with relatively flat contours.
[0004] Contemporary bunker maintenance is a major part of a golf course superintendent's responsibilities. Indeed, the time required to maintain bunkers at their expected high degree of quality can be challenging, particularly on courses that include upwards of a hundred bunkers or more. While maintenance crews spend a certain amount of time repairing bunker damage resulting from golf play, the majority of bunker maintenance is associated with repair from rain events and other environmental causes. Indeed, when a rainstorm occurs, the required repair work on bunkers may be extreme. For example, when a storm event occurs, the sand can be washed from the high spots on bunker slopes to lower regions in the bunker, exposing the subsoil on the slopes. The sand can be contaminated by subsoil color or even become mixed with stone particles that form the lower drainage area of a bunker. Inasmuch as this contamination is almost impossible to remove the sand, the old sand is usually removed and replaced with fresh sand, increasing bunker maintenance costs.
[0005] There have been some attempts in the past to address these problems associated with golf course bunker maintenance. In some cases, fabric liners have been installed as a barrier between the subsoil and the bunker sand. However, these liners tend to degrade over time, and are known to have a limited holding capacity, particularly on slopes. Liners are also held in place by metal stakes that may become exposed (especially in northern climates) due to ground freeze/heaving, etc.
[0006] Instead of a liner formed of as a sheet of material, other solutions have used spray coatings of a material over the subsoil. In some cases, a concrete spray is used. Again, this material tends to degrade over time and is especially sensitive to the temperature variations associated with northern climates (particularly ground freeze). These coatings are also difficult to repair and minimize the ability of the course to modify the bunker design without totally demolishing the concrete material.
[0007] Various types of aggregate materials have also been used as a thin boundary layer between the subsoil and the sand, creating an area with improved drainage and defining a physical boundary between the sand and the subsoil. Aggregates such as a bituminous layer with stone aggregate, polymer spray stone aggregate and rubber-polymer layers with stone aggregate have all been used. Regardless of the material selection, these aggregate structures have been found to have limited holding capacity against steep bunker slopes and tend to move downward over time, thus causing the covering sand to move as well. Again, these aggregate arrangements are difficult to repair and require a total bunker reconstruction if a design change is desired.
[0008] Thus, a need remains in the art for an arrangement that provides the drainage characteristics necessary to maintain the longevity and appearance of a golf course bunker, while providing the necessary protection of steep slopes and allowing for bunker design modifications to be accommodated.
SUMMARY OF THE INVENTION
[0009] The needs remaining in the prior art are addressed by the present invention, which relates to improvements for golf course bunkers and, more particularly, to the creation and utilization of modular, porous bunker paver blocks to improve the longevity and appearance of sand bunkers.
[0010] In accordance with one embodiment of the present invention, golf course bunker drainage system has been developed that is a modular structure taking the form of a plurality of porous bunker paver blocks formed of material exhibiting vertical and horizontal infiltration rates similar to bunker sand. The plurality of porous bunker paver blocks is disposed as a boundary layer between a bunker subsoil bottom surface and overlying bunker sand, allowing rainwater to efficiently drain away from the bunker sand while also maintaining the integrity of the bunker shape and preventing movement of sand and other materials along steeply sloping bunker sidewalls.
[0011] The bunker paver blocks are preferably formed to have side and end faces of a form that allows for the blocks to interlock as they are placed next to each other. The top surface of the bunker paver blocks can be textured to promote adherence of the bunker sand to the block, and the bottom surface of the blocks can be textured to help anchor the blocks in place along the bottom surface of a bunker.
[0012] Other and further aspects and embodiments of the present invention will become apparent during the course of the following discussion and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Referring now to the drawings, where like numerals represent like parts in several views:
[0014] FIG. 1 is a top view of an exemplary bunker paver block 10 formed in accordance with the present invention;
[0015] FIG. 2 is a top view of a plurality of bunker paver blocks, as disposed in an interlocking arrangement, as may be used within a golf course sand bunker;
[0016] FIG. 3 is a cut-away side view of an exemplary golf course sand bunker, illustrating the placement of the bunker paver blocks of the present invention with respect to the other components of a typical bunker;
[0017] FIG. 4 is a cut-away side view of a set of three bunker paver blocks, illustrating different types of textured top surfaces useful for binding bunker sand thereto; and
[0018] FIG. 5 is a close-up, cut-away side view of a portion of a sand bunker, formed to include modular paver bunkers with a serrated surface, formed in accordance with the present invention.
DETAILED DESCRIPTION
[0019] FIG. 1 is a top view of an exemplary bunker paver block 10 formed in accordance with the present invention. Importantly, bunker paver block 10 comprises a pervious or porous material, such vulcanized rubber, plastic or crumb rubber with a binding agent. Acceptable binding agents include polymer adhesives, bituminous asphalt, epoxy-based materials, or the like. New or recycled materials (or a combination thereof) may be used to form the bunker paver blocks, as long as the created bunker paver block exhibits the desired pervious/porous properties. Moreover, any suitable manufacturing process may be used to form the paver blocks and is not considered to be germane to the present invention.
[0020] In accordance with the present invention, bunker paver 10 is formed as a pervious or porous structure such that its infiltration rate (both horizontal and vertical) are at least similar to the infiltration rate of the bunker sand overlying the bunker paver. With this property, bunker paver blocks 10 create the drainage properties required for a golf course sand bunker, while the modular nature of the interlocking paver blocks permits them to be arrangement and re-arranged as necessary as bunker designs are modified.
[0021] Continuing with reference to FIG. 1 , bunker paver 10 is illustrated as including a pair of opposing end faces 12 , 14 and a pair of opposing side faces 16 , 18 . In a preferred embodiment of the present invention, the topology of bunker 10 as defined by faces 12 , 14 , 16 and 18 is designed to allow for adjacent bunker paver blocks to interlock in a manner that allows for the overall plurality of bunker paver blocks to hold each other in place.
[0022] FIG. 2 is a top view of a plurality of bunker paver blocks, as disposed in an interlocking arrangement, as may be used within a golf course bunker. As shown, a top “row” of bunker paver blocks 10 - 1 , 10 - 2 and 10 - 3 are disposed adjacent to one another, with end face 12 - 1 of bunker paver block 10 - 1 positioned adjacent to end face 14 - 2 of bunker paver block 10 - 2 . Similarly, end face 12 - 2 of bunker paver block 10 - 2 is positioned adjacent to end face 14 - 3 of bunker paver block 10 - 3 . For the sake of example, it is presumed that end face 14 - 1 of bunker paver block 10 - 1 is disposed towards the center C of an associated bunker (not shown), with the paver blocks then positioned against an upwardly sloping wall of a bunker, with bunker paver block 10 - 3 positioned towards an upper edge E of the bunker.
[0023] A second row of bunker paver blocks is shown as interlocking with the first row as described above. In particular, side face 18 - 4 of bunker paver block 10 - 4 is shown as positioned to mate with a right-hand half of side face 16 - 1 of bunker paver block 10 - 1 and a left-hand half of side face 16 - 2 of bunker paver block 10 - 2 , similar to a brick laying pattern. A second bunker paver block 10 - 5 of the second row is shown as interlocking in a similar fashion with bunker paver blocks 10 - 2 and 10 - 3 . A third row of bunker paver blocks 10 - 6 , 10 - 7 and 10 - 8 is also shown in FIG. 2 as interlocking with the pair of bunker paver blocks 10 - 4 and 10 - 5 of the second row.
[0024] The topology of the side faces of bunker paver blocks 10 is shown to provide this interlocking to provide mechanical stability to the combination paver blocks forming the bunker drainage system. This mechanical stability will allow for the bunker paver blocks to remain in place, particularly along steep sloping sidewalls, overcoming a major problem associated with various prior art arrangements. When bunker sand is then placed over the plurality of bunker paver blocks, the additional weight will further provide mechanical stability, with some of the sand working into the interfaces between adjacent paver blocks and provide further rigidity to the interlocking structure.
[0025] An added benefit of the arrangement of the present invention is that by virtue of utilizing a plurality of modular bunker paver blocks, a natural microdrain channel 20 will be formed at the edges where paver blocks abut one another. Microdrain channels 20 provide additional paths for drainage of rain from the bunker. These additional microdrain channels are not found in prior art, unitary bunker liners.
[0026] FIG. 3 is a cut-away side view of an exemplary golf course sand bunker, illustrating the placement of the bunker paver blocks of the present invention with respect to the other components of a typical sand bunker. As shown, a sand bunker is formed by creating a hollowed region of a desired contour in a portion of native soil (or subsoil) 30 . A drainage area 32 is formed at the lowest natural portion of the contour, and a drainage pipe 34 is disposed in drainage area 32 . While not always used, an additional drainage layer 36 of aggregate stone (or other suitable material) may be disposed across an area of the exposed bunker in the region of drainage area 32 .
[0027] In accordance with the present invention, a plurality of bunker paver blocks 10 is then positioned over subsoil 30 (or drainage layer 36 , if used), where the individual, modular bunker paver blocks are placed within the bunker in the interlocking pattern as shown in FIG. 2 . Beyond the porous nature of the block material itself, microchannel drains 20 at the interface between adjacent blocks 10 also assist in quickly and efficiently draining water from the bunker sand. Bunker sand 40 is then placed over the positioned bunker paver blocks 10 . Clearly, the inclusion of modular bunker paver blocks 10 provides a boundary between bunker sand 40 and subsoil 30 , preventing the sand from being contaminated by the subsoil. This same protection as provided by modular bunker paver blocks 10 prevents any aggregate material of layer 36 from infiltrating the bunker sand.
[0028] In one exemplary embodiment, a bunker paver of the present invention may be formed to include a rough or corrugated top surface. This feature has been found to stabilize the sand overlying the paver and hold the sand in place, particularly on bunker slopes. FIG. 4 is a cut-away side view of a set of three bunker paver blocks 10 -A, 10 -B and 10 -C, each exhibiting a different textured top surface 40 useful for adhering sand to the paver blocks. It is to be understood that the forms shown in FIG. 4 are exemplary only and various other roughened topologies may be formed on a bunker paver top surface in accordance with the teachings of the present invention.
[0029] Referring to FIG. 4 , bunker paver 10 -A is shown as having a top surface 42 -A which illustrates a squared-off corrugation. The accumulation of sand within trenches 44 -A will assist in helping the sand particles to remain in contact with each other and minimize the movement of sand on bunker slopes.
[0030] Bunker paver 10 -B is shown as including a serrated top surface 42 -B. In this case, the placement of bunker paver blocks 10 -B in a bunker such that edges 44 -B point upward (towards the edge of the bunker) so as to allow for sand to naturally collect in each section. Again, this particular arrangement include a serrated top surface of a bunker paver, prevents movement of bunker sand (particularly on slopes). Bunker paver 10 -C is shown as having a top surface 42 -C of a scalloped design, creating indented areas for sand accumulation.
[0031] FIG. 5 is a close-up, cut-away side view of a portion of a sand bunker, formed to include modular paver bunkers with a serrated surface, formed in accordance with the present invention. As shown, a set of modular bunker paver blocks 10 is positioned across the bottom surface of the bunker, covering both subsoil 30 and drainage aggregate 36 . Adjacent bunker paver blocks 10 are disposed in an interlocking pattern (as shown in FIG. 2 , for example), with an exemplary end edge 12 of a first bunker paver positioned against an end edge 14 of an adjacent bunker. Microdrain channels 20 are evident in this view.
[0032] As described above, the plurality of modular bunker paver blocks 10 shown in FIG. 5 are formed to include serrated top surface 42 -B. Bunker paver blocks 10 are positioned with edges 44 -B pointing upwards, allowing for bunker sand to accumulate in regions 46 -B. By accumulating sand in this manner, the possibility of sand releasing from sloping bunker sidewalls is greatly reduced. In the particular embodiment as shown in FIG. 5 , bottom surface 48 of bunker paver blocks 10 is also roughened, where this additional texture on bottom surface 48 assists in fixing blocks 10 in place against the subsoil (and/or aggregate material) on the bottom of an associated bunker.
[0033] By virtue of using modular bunker paver blocks in accordance with the present invention, the limitations of the prior art solutions are overcome and various advantages become apparent. In particular, the interlocking arrangement of modular paver blocks creates a mechanical force that holds the arrangement in place, minimizing the possibility of bunker damage along sloping sidewalls (as well as the release of sand from these sidewalls).
[0034] The modular paver blocks are preferably sized so that an individual may perform their placement arrangement without needing other assistance. If necessary, the bunker paver blocks may be cut to properly fit along the edges of a sand bunker or modify internal paver block angles. Moreover, if an individual bunker paver becomes somehow damaged or breaks, the maintenance personnel need only remove the damaged paver block and replace it, leaving the rest of the bunker paver blocks undisturbed.
[0035] In situations where it is desired to modify the design of a bunker, the uncovered bunker paver blocks can be removed, realigned, etc. in order to change the particular bunker design. The modularity also allows for the various paver blocks to slightly move as the ground underneath the bunker heaves during freezing and warming conditions, absorbing this movement without causing the overall bunker integrity to be compromised.
[0036] Although only some preferred embodiments of the invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the preferred embodiments without departing from the advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention. | A golf course bunker drainage system has been developed that is a modular structure taking the form of a plurality of porous bunker paver blocks formed of material exhibiting vertical and horizontal infiltration rates at least the same as bunker sand. The plurality of porous bunker paver blocks is disposed as a boundary layer between a bunker subsoil bottom surface and overlying bunker sand, allowing rainwater to drain into the subsoil, with excess rainwater directed away from the bunker sand. The use of bunker paver blocks also maintains the integrity of the bunker shape and prevents movement of sand and other materials along steeply sloping bunker sidewalls. | 4 |
This application claims benefit of international application PCT/EP95 /05182, filed Dec. 30, 1995.
BACKGROUND OF THE INVENTION
The present invention relates to an automated pile raising machine for fabric.
Pile-raising is a process giving a fabric a hairy, velvet-like appearance while simultaneously increasing the softness and heat insulating, as well as colour, characteristics thereof.
In raising machines, in particular in raising machines with metal trimmings, cleaning brushes are provided which are suitable for cleaning and sharpening the trimmings of pile and counter-pile cylinders. In particular, at least one pair of brushes must be provided, one of which can act on the trimmings of the raising pile cylinders, and the other on the trimmings of the counter-pile cylinders. In order to correctly perform such cleaning and sharpening tasks, the brushes are required to revolve perfectly in phase with the respective cylinders.
At present, this necessary timing of rotation of brushes and pile and counter-pile cylinder sets is accomplished by providing various types of mechanical transmission means, e.g., constituted by chains, toothed belts, gear wheels or sprocket wheels, or the like, between the pulleys or sprocket wheels of the motor means driving the revolving drum, and pulleys arranged integral with the shafts of the brushes.
The above structure results, for example owing to the natural arising of clearances in chain meshes, in rupture of belt and gear wheel teeth, and so forth, in the possibility of sudden loss of timing and/or motion transmission between the parts. Or, the loss can be also caused by external events, such as wear or improper service.
Although sometimes also a sensor is provided which in a relatively short time can cause the revolution-driving motor means to be stopped, the processed fabric gets often wound on the brushes, which remain in contact with the raising cylinders, with consequent damaging and blocking which imply long dead times of the whole raising machine.
Furthermore, it may happen that the cleaning brushes revolve out-of-phase relative to the drum, until they cause the irreparable damaging of the needles and metal points installed on the surfaces of brushes and cylinders.
A first minor remedy, however not so effective, is constituted by the presence of clutch means between the transmission means which transmit the revolutionary motion to the brushes, and the same brushes, which may slide by an angle of 180° on an average, or, at maximum, corresponding to a complete revolution between the parts. However, in any case, fabric winding on the brushes may still occur in case of missed timing of the revolving elements.
A second type of remedy to limit the damage in the case lack of synchronism is constituted by a torque-limiting coupling, which rapidly acts on the cleaning brushes. Unfortunately, as a rule, regulating such a coupling is rather complex, because the intervention threshold torque value must be set by taking into account both the (relatively high) starting-up torque and the steady-state operating torques, which are considerably lower than the starting-up torques.
Furthermore, the presence of the above-cited transmission means implies, as a natural consequence thereof, a certain structural and maintenance complexity of the raising machine.
It should also be underlined that, should the brush/drum cylinder timing have to be changed, a whole series of changes in parts arrangements and adjustments and regulation operations must be carried out, possibly including all those mentioned above, with considerable increases in production costs due to machine dead times and lack of automation and reliability as to the correct execution of requests and necessary changes.
SUMMARY OF THE INVENTION
The purpose of the present invention is of providing a raising machine, in particular with metal trimmings, which does not display any of the above-cited drawbacks.
A further purpose is of providing a raising machine of the above-cited type which reduces as extensively as possible the need for interventions and in a nearly automatic way performs the several functions of correct motion transmission and mutual timing of the parts, while avoiding any possible types of damaging of its structural parts.
The adoption of single motor means or electrical motor units associated with the drum and at least one of the cleaning brushes, all of them being piloted by an electric-electronic system, makes possible the necessary timing to be accomplished with getting rid of the traditional toothed pulley transmission means with the relevant gear wheels which, as said, do not secure the necessary reliability.
It is important to observe that the timing existing in a machine according to the present invention is not rigidly fixed forever, as, on the contrary, the case is for the traditional machines using the torque limiting coupling.
On the contrary, in the machine according to the present invention, one can rapidly and finely act on synchronization. This is particularly useful in those cases when fabric penetrates between the drum and the cleaning brushes, owing to slowing-down, tearing or breakage of the same fabric.
Moreover, the elimination of the torque limiting coupling contributes to render the structure of the raising machine of the present invention still simpler and hence cheaper.
BRIEF DESCRIPTION OF THE DRAWING
The characteristics and advantages of an automated raising machine according to the present invention will be clearer from the following exemplifying, non-limitative disclosure, made by referring to the accompanying schematic drawings, in which:
FIG. 1 shows a cross-sectional view of a first exemplifying embodiment of a raising machine according to the present invention, having two mutually superimposed drums;
FIG. 2 shows an enlarged side view limited to the area of the lower drum and to the brush bearing plate of the machine shown in FIG. 1;
FIG. 3 shows an enlarged bottom plan view according to arrow "F" of FIG. 2, of the only brush bearing plate;
FIG. 4 shows a schematic front view of a second embodiment of the raising machine according to the present invention; and
FIG. 5 shows a block diagram of the electric-electronic system of the machine of FIG. 4.
DETAILED DESCRIPTION
Referring first to FIGS. 1-3, a possible--however, non-limitative--embodiment is shown, of an automated pile raising machine for fabric according to the present invention.
This exemplifying embodiment illustrates a raising machine of the type having two mutually superimposed drums; however, of course, the raising machine of the present invention may be of the single-drum type or in-line multiple-drums-type as well.
FIG. 1 schematically illustrates a raising machine having two mutually superimposed drums, generally indicated by (11), in which, on a carrier/housing structure indicated in figure by a side wall (12), two drums (13) are supported/housed. These drums (13) revolve around shafts (14) driven to revolve by a respective motor means or ratiomotor means (15) and each of them supports a set of raising, or processing, cylinders, respectively operating in pile mode (16) and in counter-pile mode (17), arranged according to drum generatrices and mutually alternating.
The cylinders (16) and (17) are driven to revolve, by mutually independent drive means according to mutually independent revolution directions by transmission means schematically indicated at (18) and motor-driven at 18a).
A fabric to be processed, schematically indicated at (19), which unwinds from a feed roll, not shown in figure, is fed to the raising machine and, running on return rollers (20) and other devices, comes to the surface of the first drum (13). Here, the fabric runs on the pile (16) and counter-pile (17) processing cylinders, revolving in opposite directions. After leaving the first drum (13), the fabric runs along a similar path on the second, underlying drum (13) before leaving the machine and being sent, e.g., to a new roll winding. Further alternative paths, e.g., on one single drum (13), are indicated in phantom line at (19').
At that zone of the side surface of the drum in which the pile and counter-pile raising cylinders (16) and (17), respectively, are not in contact with the fabric (19), a pair of brushes (21) and (22) are arranged. The brushes (21) and (22) perform the task of cleaning and sharpening the trimmings provided on the raising cylinders (16) and (17). At each drum (13), the brush (21) acts on a set of pile cylinders (16) and the brush (22) acts on a set of counter-pile cylinders (17).
In a machine according to the present invention, a motor means, schematically indicated at (23), controls and regulates the angular speed, e.g., of the brush (22). In fact, the motor means (23) is directly constrained onto the shaft of the brush (22) to which also a sprocket wheel (27) is keyed. On the latter, a toothed belt (25) winds around which is suitable for transmitting the revolution motion also to a second sprocket wheel (26) which is integrally arranged onto the shaft of the second brush (21).
Furthermore, the toothed belt (25) winds around a third sprocket wheel (24), which regulates the tension of the toothed belt (25). It should be observed that the toothed belt (25) winds around the sprocket wheels (26) and (27) on opposite sides thereof, so as to cause the brushes to revolve in mutually opposite directions. In fact, the brushes (21) and (22) are required to revolve in phase in the revolution direction of the respective cylinders (16) and (17).
Furthermore, according to the present invention, it should be understood that both the ends of the sprocket wheels (26) and (27) carrying shafts and the respective brushes (21) and (22) and the third sprocket wheel (24) are supported on a plate (28).
This plate (28) is of an elongated shape which approximately follows the circular outline of the side surface of the drum (13) and, at one of its ends is hinged, at (29) onto the side wall (12) of the carrier structure of the raising machine. At its other end, the plate is hinged in (30) onto the end of a stem (31) of the ram of a cylinder (32), which is rotatably hinged, at (33), onto the side wall (12).
FIG. 2 shows, in solid line, the position in which the stem (31) of the ram of the cylinder (32) is extended outwards so as to cause the plate to come into engagement with a shoulder element (34) which is integral with the side wall (12) and consequently cause the respective brushes (21) and (22) to come into engagement with the respective pile (16) and counter-pile (17) cylinders. Clearly, when the stem (31) gets retracted inside the cylinder (32), the plate (28) gets so rotated as to cause the brushes (21) and (22) to move away from the raising cylinders of the respective drum (13), as is schematically illustrated in phantom line in FIG. 2.
FIG. 3 clarifies to a greater extent the positioning of the motor means (23) on the shaft of the brush (22), the hinging (29) of the plate (28) onto the side wall (12), and the positioning of the cylinder (32) used in order to cause the plate (28) to swing.
From FIG. 2, one will furthermore see the presence of a set of sensors which detect, instant-by-instant, the angular position of the drum and of the brushes. In fact, a first sensor (35) is provided so as to be integral with the side wall (12), and is suitable for detecting, e.g., a plurality of notches (36) provided on a plate (37) integrally revolving with each of drums (13). Clearly, the number of notches is correlated with the number of raising cylinders provided on the drum (13).
A second sensor (38) and a third sensor (39) are installed on the plate (28) so as to detect relevant notches provided, as in the preceding case, on plates, integrally revolving with both brushes (21) and (22), so as to check the angular position thereof.
The three sensors (35), (38) and (39) are, of course, connected, through connecting lines (42), with an electronic apparatus, which is schematically shown at (40), which detects the signals. Due to the presence of a processor, schematically depicted in (41), the electronic equipment (40) verifies the predetermined timing of the several revolving elements, i.e., of their drive motor means, through connecting lines (43). In that way, a perfectly timed correlation is realized between the drum, or the raising rollers thereof, and the brushes designed to interact on the raising rollers
The presence of sensors (38) and (39) allows, in the event when a lack of cylinders/brushes timing is detected, the electronic equipment (40) to immediately intervene, by causing the cylinder. (32) to retract the stem (31) and consequently cause the brushes (21) and (22) to get disengaged from the raising cylinders (16) and (17). In that way, the fabric is prevented from winding around the brushes, thus avoiding burdensome machine stops and damage possibilities. This disengagement takes place also in the event of electrical and/or pneumatic power supply interruption.
Briefly, operation of the raising machine according to this first embodiment (FIGS. 1-3) of the present invention is as follows.
In the illustrated example, at starting-up time, the raising machine has its plate (28) so positioned that the brushes (21) and (22) are disengaged from the raising cylinders (16) and (17) of the drum (13). Upon machine enabling, the drum starts revolving, driven by its motor means (15), while the pair of motors (18a) with transmission means (18) cause both groups of raising cylinders (16) and (17) to start revolving. The motor means (23) drives the brushes (21) and (22) to revolve, and the correct timing of brushes, drum, and drum raising cylinders is immediately checked by means of sensors (35,38,39). In case of positive result, the plate (28) is pushed to rotate by the ram/cylinder (32) and the brushes get engaged with the respective raising cylinders. This check continues throughout machine running, at each revolution of the brushes, so that, when an incorrect timing is detected, the plate is caused to immediately return back to its initial (start-up) position, with the brushes and raising cylinders getting consequently disengaged.
The advantage clearly emerges of such an inventive technical solution, in which the disengagement is not enabled following mechanical breakages, and in any case the above-cited disengagement is accomplished, with the drawbacks which affect the machines known from the prior art being completely overcome.
This possibility of stopping and moving the brushes away from the drum is particularly important in the event when the fabric winds around and is caught by the brushes. In fact, any risk of damage to the metal trimmings and to the same cylinders is avoided. Furthermore, advantageously, no clutches have to be installed between the transmission means which transmit the revolutionary motion to the brushes and the same brushes, with the structure of the machine being simplified.
One should observe that the motor means (23) which determines the control and regulation of the angular speed can be a stepper motor, a brushless motor, a drive system with an inverter, or the like.
In the same way, in the disclosed and illustrated exemplary embodiment, a transmission by a toothed belt is provided between both brushes; however, in an equivalent way and without departing from the scope of the present invention, either two gear wheels keyed on the shafts of the respective brushes, or a chain transmission, or similar means can be provided.
One can even think of installing on each brush a respective motor means, thus eliminating any problems associated with incorrect transmission timing, and electronically correlating the rotation of both motor means.
The presence of sensors operatively connected with the electronic equipment makes furthermore possible a nearly immediate and automatic timing to be accomplished of the brushes and drum cylinders, e.g., in the event when the operating direction of the machine must be rapidly changed. Thus, mechanical elements to be actuated in case of brushes and drum rotation changes are got rid of with an automatically reversible machine with drums operating in both directions being provided.
The elimination of the transmissions--which, on the contrary, are provided in the presently used raising machines--besides increasing timing reliability, allows the necessary machine servicing to be sharply reduced. Of course, also manufacturing the various component parts is considerably simplified by the elimination of the components of the several transmissions.
Referring to FIGS. 4 and 5, a second embodiment of a raising machine according to the present invention will be discussed now.
The raising machine, generally indicated by (51), comprises a revolving drum, indicated at (52), on the periphery of which the pile cylinders and the counter-pile processing cylinders, indicated by the reference numerals (57) and (58), respectively, are arranged in a mutually alternating arrangement, and are caused to revolve around their revolution axis (535), while simultaneously revolving around the drum (52).
By the reference numeral (53), an electronic encoder is indicated--referred to, from now on, as the "encoder"--integrally mounted on the drum (52), which converts the analog data corresponding to the angular positions of the drum (52) into digital signals.
The encoder (53) generates a determined number of voltage pulses per each revolution of drum (52). Furthermore, the encoder (53) generates a voltage pulse every time that it runs beyond a reference notch (536) provided on the framework (51') of the machine (51). Such a pulse is commonly referred to as the "zero pulse", because it corresponds to the initial phase of the periodic function which represents the revolution motion of the drum (52).
By (56) and (56'), two cleaning brushes are indicated, each of which is provided with two trimmings, indicated with the reference numerals (520) and (520'), equipped with needles, indicated by with the reference numerals (521) and (521'), acting as cleaning organs inside the trimmings (57') and (58') of the processing cylinders (57) and (58).
The trimmings (520) and (520') are installed on the contours of the brushes (56) and (56'), in such a way that the needles (521) and (521') will enter between the metal points (524) and (524') with which the processing cylinders (57) and (58) are equipped. Each of the cleaning brushes (56) and (56') performs the task of cleaning a determined set of processing cylinders, i.e., the pile cylinders (57), or the counter-pile cylinders (58).
By the numerals (510) and (510'), two electrical motor units are indicated, which transmit motion, through pulleys (59) and (59'), to the cleaning brushes (56) and (56'). By the numerals (55) and (55'), two proximity sensors are indicated which are respectively installed on each of the brushes (56) and (56').
Each of the sensors (55) and (55'), according to whether the sensor is installed on the brush (56) which performs the cleaning of the pile cylinders (57), or the sensor is installed on the brush (56') which performs the cleaning of the counter-pile cylinders (58), detects the passage of the set of corresponding processing cylinders and supplies, for each set of cylinders, an electrical output signal constituted by a set of voltage pulses, i.e., one pulse per each passage of the sensor in front of each relevant processing cylinder.
From the position of zero pulse, relevant to the passage of encoder (53) beyond the reference position (536), inside the electric-electronic system (537) begins, per each drum (52) revolution, the comparison between the phase of the periodical function which represents the revolution motion of both brushes (56) and (56') and the phase of the periodical function which represents the revolution motion of the drum (52), associated with the motion of the processing cylinders (57) and (58).
In particular, referring to FIG. 5, in the block diagram of the electric-electronic system (537) of the machine the following elements can be located:
a detector unit (517) constituted by the encoder (53) and both proximity sensors (55) and (55'), which converts the analog signals corresponding to the angular positions of the drum (52) and of the brushes (56) and (56') into digital signals to be sent to an electronic measuring unit (516);
an electronic measuring unit (516) which collects and processes said digital signals, constituted by a programmable frequency divider (511), equipped with an electronic module (522) for input data entering through the keyboard (533)!, a frequency-to-voltage converter (512), two comparators (513) and (513') and two adder devices (of the type equipped with operational amplifiers) (514) and (514');
an electrical driver unit (54) constituted by two driver circuits (515) and (515') (each of which is referred to, from now on, as "driver"), by three electrical motor units (510), (510') and (519) which drive the cleaning brush (56), the cleaning brush (56') and the drum (52), respectively, and a pilot circuit (525) which drives the electrical motor unit (519) of the drum (52);
a power supply unit (518) which controls the pilot circuit (525); and
an electronic control circuit (523) which watches for the actual presence of the electrical signals generated by the encoder (53) and the proximity sensors (55) and (55') and, based on them, verifies the preservation of the desired phase synchronism.
In particular, the reference numeral (511) indicates a frequency divider constituted by binary circuits and programmable by means of an electronic module (522), which makes it possible such data to be entered through a keyboard (533), as the number of divisions of frequency of signals coming from encoder (53) and the number of processing cylinders (57) and (58) present on drum (52).
The electronic module (522) automatically calculates the "synchronism positions", i.e., the angular positions of encoder (53) relative to a radial reference axis (538) (which, in the illustrated case, is also vertical). At those positions, the electric-electronic circuit (537) verifies and possibly corrects the phase shift between the revolution motion of the drum and the revolution motion of the brushes in order to preserve the necessary synchronism.
In practice, the corresponding angle to each synchronism position is equal to the ratio of the whole round angle to the number of processing cylinders (57) and (58) present in the raising machine (51). As the number of the cylinders (57) and (58) usually is 16, 24 or 36, the value of the angle will be comprised within the range of from 10 to 20 degrees.
Furthermore, the electronic module (522) is provided with a liquid crystal display (532) which displays the data when the latter are entered by the user through the keyboard (533), and furthermore displays the possible synchronism error between the phase of the drum (52) and of the brushes (56).and (56').
If a synchronism error is detected, an acoustical alarm signal is simultaneously enabled. The operator is thus given the possibility of evaluating the extent of such an error and of actuating, or less, based on the result of such an evaluation, the drivers (515) and (515)' (On the keyboard (533) an option key can be provided in order to select the drivers (515) and (515') enabling/disabling modalities.), or of not taking this alarm into consideration, in at all particular moments, such as, e.g., machine (51) starting-up or stopping transients when the implied inertias can cause phase errors which are larger than those errors which can be detected during normal steady-state machine (51) running and which, however, do not cause any particular damages owing to the low operating speed and the short time interval during which they occur.
The digital signal constituted by voltage pulses, generated by the encoder (53) and corresponding to the passage of the encoder (53) before each position of synchronism relatively to the radial reference axis (538) is sent to the input of the programmable divider (511).
To the input the zero pulse, i.e., the voltage pulse generated by the encoder (53) at its passage before the reference notch (536) is sent as well.
The digital signal corresponding to the synchronism positions generated as the output signal from the programmable divider (511) is sent to a first phase comparator (513) which compares the phase thereof to the phase of signal coming from sensor (55) installed on brush (56) and to a second phase comparators (528) which compares the phase thereof to the phase of signal coming from sensor (55') installed on brush (56').
Each error detected during the comparison processes is added, with its algebraic sign, through the adder devices (514) and (514'), to a baseline reference value for drum (52) angular speed. The reference signal is an electrical voltage signal and is derived either from the encoder (53), installed on the drum (52), by means of the frequency-to-voltage converter (512) which converts the frequency of the digital signal corresponding to the synchronism positions into a voltage signal, or by means of a tachometrical generator (not shown in the drawings also integral with the drum (52).
Both so-corrected output signals from both adder devices (514) and (514') are respectively sent to both drivers (515) and (515') which feed both electrical motor means or motors (510) and (510'), driving the cleaning brushes (56) and (56'), with power.
The baseline reference signal for drum angular speed displays a first portion during which the angular speed increases with time according to a directly proportional trend (i.e., during the time period immediately following machine start-up), then a second portion during which the angular speed remains constant (steady-state machine operation), then, finally a third, decreasing-speed portion, which starts when power supply to the machine is switched off and lasts until the drum (52) eventually stops.
The algebraic addition operation of such baseline reference signal to the signal coming from each of comparators (513), (528) is necessary in order to check the sensibility of the system and prevent that, at any extremely small phase error between the drum (52) and the brushes (56) and (56'), the electronic measuring unit (516) commands anyway the enabling of the electrical motor means (55) and (55').
The reference numeral (523) indicates an electronic control circuit which checks that the digital output signals from the encoder (53) and the proximity sensors (510) and (510') are actually present.
In practice, this function is obtained by taking the output signals from the encoder (53) and the proximity sensors (55) and (55') and performing a further phase comparison, at all analogous to the preceding one. In fact, a programmable divider (511') to the input of which the same signals are sent which come from the encoder (53) and the proximity sensors (55) and (55'); an electronic module (522') which divides the frequency of said signals and is entered as the electronic module (522); and two phase comparators (513') and (528'), to the input of which the signals are sent which come from the divider (511') and, respectively, the proximity sensors (55) and (55'), are used.
The output signals from the phase comparators (513) and (528') are sent each to a Schnitt trigger comparator (529) and (529'), at the input of which also the signal which comes from the phase comparator (513) and the signal which comes from the phase comparator (528), respectively, are present.
The Schmitt triggers (529) and (529') perform a comparison between the input signals and, if differences between the signals are detected, enable an alarm visual and sound signalling procedure, by means of the devices (531) and (531'), e.g., piezoelectric buzzers or LED diodes. If, due to any reason, the encoder (53) and/or the proximity sensors (55) and (55') do not supply output signals or supply them improperly, the control circuit (523) detects such signal lack/error in order to secure a better measurement reliability.
The control circuit (523) is structurally similar to the electronic measuring unit (516) and can therefore be easily reproduced based on electronic unit (516). In that way, the overall manufacturing costs can be reduced.
A further advantage offered by the present invention is the possibility the raising machines manufacturer is given, of standardizing its production by installing the same electric/electronic system (537), without any modifications and/or adjustments, on machines of the type indicated with (51), having a different number of processing cylinders (57) and (58). In fact, it is enough that the user enter the number of processing cylinders (57) and (58) by means of the keyboard (533) of the electronic module (522).
Another drawback observed in the raising machines (51) known from the prior art, is the impossibility of submitting the metal points (524) and (524') of cylinders (57) and (58)--which are known to show only seldom a same wear rate--to a differentiated sharpening operation.
On the contrary, in the raising machine (51) according to the present invention, as the movement of drum (52) can be made independent from the movement of brushes (56) and (56'), the metal points (524) and (524') of each preselected processing cylinder (57) or (58) can be sharpened by operating on it, with drum (52) being stationary and brushes (56) and (56') being kept moving, until the end of the sharpening process which, obviously, implies that the revolution motion of cylinder (57) or (58) around itself continues, as driven by auxiliary means (not shown), like, e.g., a revolving chuck.
Finally, it is important to remark that, by operating in that way, a specific action of desired duration is obtained of the cleaning brush (56) or (56') on the metal points (524) or (524') of the processing cylinder (57) or (58), with a particularly effective sharpening being consequently obtained.
Furthermore, such a sharpening method offers a number of other advantages, such as:
the angular speed of the cleaning brush (56) or (56') can be adjusted as a function of effectiveness and, therefore, a time saving during this step is obtained;
the fabric need not be removed from machine (51) and therefore the dead times are avoided which are due to operation interruption and to fabric installation on the rollers before re-starting the drum
cleaning the processing cylinders (57) and (58) and sharpening the metal points (524) and (524') can be automatically carried out during the needed time for drum (52) to revolve by one single revolution; and
the average life of the trimmings (57') and (58') which contain the metal points (524) and (524') is longer than the average life of the trimmings (57') and (58') submitted to a traditional sharpening operation. In fact, traditionally, upon considering the necessary time for unloading the raising machine (51) and the impossibility of sharpening a predetermined set of processing cylinders (57) or (58), the users prefer to use the trimmings (57' and 58') until their wear threshold, and then replace all of them. Unfortunately, after such a replacement, the freshly installed trimming (57') or (58') requires a some-days-long break-in run during which the fabric is not perfectly processed.
All these time wastes resulting eventually in missed production or fabric quality lowering, can be prevented by systematically operating according to the modalities provided according to the present invention.
Clearly, many changes may be supplied by those skilled in the art to the raising machine according to the present invention, without departing from the scope of protection of the inventive idea, and, clearly, when practicing the invention the shapes of the illustrated details can be different, and same details may be replaced by technically equivalent elements.
For example, for particular fabric types and/or processes, reversing the direction of revolution of drum (13) or (52) of the machine (and, consequently, of the pile or counter-pile processing cylinders (16, 57) or (17, 58), respectively, could become necessary. In that case, both cleaning brushes (21 or 56) and (22 or 56') will operate on the other cylinder set opposite to the cylinder set on which they were operating before revolution direction reversal.
If the toothed-belt/sprockets or gear wheels transmission known from the prior art are adopted, the only possible system for that purpose consists in introducing a mechanical phase shift by means of a clutch engagement/disengagement device additionally to the torque limiting coupling.
On the contrary, if the solution according to the present invention is adopted, it is enough that a switch (534) purposely installed on the keyboard (533) or in the electronic control system (523) or, anyway, in the electric/electronic system (537) be switched, which shifts the signal by the desired phase. | An automated pile-raising machine for fabric, in which the fabric is advanced about at least one drum, in contact with alternatingly interspersed pile and counter-pile rotating cylinders cleaned by respective cleaning brushes, a timing control system including sensors is provided for coordinating operation of the cylinders and brushes. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a Continuation-In-Part of my co-pending U.S. patent application Ser. No. 07/471,884 filed Jan. 29, 1990, now U.S. Pat. No. 5,011,524, which is a divisional application of my prior U.S. patent application Ser. No. 07/278,447, filed Dec. 1, 1988, now U.S. Pat. No. 4,897,099. The entire disclosure in that patent is expressly incorporated herein by this reference.
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for providing purified ice pieces and purified liquid water from a source of unpurified liquid water. More particularly, the present invention provides an alternative approach to melting ice pieces in a method and apparatus of the type generally disclosed in my aforementioned U.S. Pat. No. 4,897,099.
In my U.S. Pat. No. 4,897,099 I disclose a method and apparatus for forming purified ice pieces from unpurified water, such as tap water. The ice pieces are periodically harvested and collected in a bin, the bottom of which is heated as necessary to melt desired quantities of the ice to provide a supply of purified water.
In the embodiment disclosed in FIG. 2 of my aforesaid patent, heat for melting the ice is derived from a flow of room air, propelled by a fan and conducted along the bottom of the ice bin.
The present invention provides the alternative method of transferring heat from the room environment to the bottom of the bin by convective fluid flow, and controlling this heat transfer by a flow control device such as an air damper or a water valve.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide an alternative method and apparatus to that disclosed in my U.S. Pat. No. 4,897,099 for applying thermal energy to a collection bin for purified ice, thereby melting some of the ice to provide and collect purified water.
In accordance with the present invention, a fluid medium such as air, or water, is brought in contact with the bottom of the ice bin. As ice is melted in the bin the fluid is cooled, thus becoming denser and heavier. It then falls in a convective downward flow through an air duct or a water pipe to a lower height level where it encounters a like fluid which has been warmed by the room environment and is thus less dense and lighter. As this fluid moves downwardly away from the bin bottom in the duct or pipe, it is replaced by warmer fluid which has been warmed by the room environment. This influx of warm fluid provides more heat to melt ice, and is in turn cooled and flows downward through the duct or pipe. In this way a continuous ice melting and fluid flow is established.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and many of the attendant advantages of the present invention will be appreciated more readily as they become better understood from a reading of the following description considered in connection with the accompanying drawings wherein like parts in each of the several figures are identified by the same reference numerals, and wherein:
FIG. 1 is a schematic flow diagram of a system constituting one embodiment of the present invention;
FIG. 2 is a schematic flow diagram of a second embodiment of the system of the present invention; and
FIG. 3 is a schematic flow diagram of still another embodiment of the system of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order to facilitate reference to the disclosure material incorporated herein from my U.S. Pat. No. 4,897,099, two-digit reference numerals appearing in the accompanying drawing are chosen to correspond to those reference numerals employed in the aforesaid patent for like elements. Three-digit reference numerals appearing in the accompanying drawings designate elements not present in the aforesaid patent. In the interest of brevity, and to facilitate understanding of the subject matter of the present invention, the following description omits discussion of the portions of the system not directly related to the invention subject matter.
Referring now to FIG. 1 of the accompanying drawings, the overall ice-forming and melting system is illustrated schematically. Compressor 9 draws refrigerant vapor from evaporator 2 and discharges it to condenser 10. Liquid refrigerant flows via liquid line 11 and metering device 12 back to evaporator 2, in a continuous refrigeration cycle. Water pressurized by pump 14 flows over plate 3, and ice pieces 5, 6, 7 and 8 are formed. When periodic harvesting is initiated, the ice pieces fall into bin 18. Bin switch 21 remains closed and thus keeps compressor 9 energized until the level of ice in bin 18 reaches the sensor element of bin switch 21, at which time the switch opens and de-energizes compressor 9. Should the ice level at bin switch 21 drop at a later time, it would close again and re-energize compressor 9. At selected times the ice collected in bin 18 is heated by a flow of ambient air warmed by the room environment and entering inlet duct 200 so as to flow in contact with heat exchange fins 38. Inlet duct 200 slopes downward from its intake to help establish a convective flow by preventing backflow. After contact with fins 38, this cooled air flows downward through down-duct 201, through damper 202, and through discharge duct 203, to mix with ambient air warmed by the room environment. A continuous convective flow is thus established.
Any ice which melts in bin 18 drains through a pipe 22, having its inlet at the bottom of the bin, into a bottle 23 or other container resting on a platform 24 hinged at a positionally fixed point 25. By "positionally fixed" it is meant that the hinge or pivot point 25 is stationary relative to the common cabinet or housing for all of the components described herein. If bottle 23 is less than full, its weight is overcome by the resilient bias force of a balance spring 26 pulling platform 24 counter clockwise (as viewed in the drawing) to swing the platform upwardly. This upward movement causes an upward movement of control link 27 connected to platform 24 at connecting pivot 28, the latter being movable relative to the common system housing. Upward movement of control link 27 causes counter-clockwise rotation of a rocker arm 29 about a fixed pivot point 30 to which it is connected at a movable pivot point 31. The rotation of rocker arm 29 causes an override switch 32 to close, thereby bypassing bin switch 21 and permitting compressor 9 to run regardless of the state of the bin switch. Extension arm 204 is attached to platform 24, and control link 205 is connected to it at movable pivot point 206. Control link 205 connects at movable pivot point 207 to control arm 208 to actuate damper 202 about fixed pivot point 209, so that when platform 24 is in the upward position, damper 202 is open. In this way, when bottle 23 is less than full, damper 202 is open and melting of ice by convective air flow continues. Ice resting on the bottom of bin 18 is thus melted at a relatively fast rate and the resulting water is drained via pipe 22 into bottle container 23.
As ice melts at the bottom of the bin, the weight of the ice pieces in the bin causes more ice pieces to continually move downwardly to the bin bottom. Meanwhile, the ice-making function continues, providing a supply of fresh ice pieces that are collected in the bin. When container 23 is full, its weight overcomes the bias force of balance spring 26 and causes platform 24 to drop (i.e., pivot clockwise about fixed pivot 25). This movement, transmitted via extension arm 204, control link 205 and control arm 208, causes damper 202 to move to a closed position, thus interrupting the convective air flow and the melting of ice in bin 18. Also, the downward movement of platform 24 is transmitted via control link 27 and rocker arm 29 to the override switch 32 which opens and leaves control of ice making to bin switch 21. The use of control link 205 to couple movements of platform 24 and damper 202 could be replaced by other practical, alternative means of achieving such a coupling. As an additional alternative precaution, for higher overall efficiency, a similar damper might be added to the inlet duct 200 and coupled in the same manner.
FIG. 2 illustrates an embodiment in which the ice melting, convective flowing medium is water. Heat exchange tube 220 is in contact with the bottom of bin 18. Warming coil 221 is in the room environment, outside of the insulated cabinet enclosure. Supply pipe 222 and return pipe 223 connect heat exchange tube 220 and warming coil 221, and all of these connected components are filled with water, or some other suitable liquid. Valve 224 is capable of shutting off flow in return pipe 223, and is actuated by a control arm 225 connected to control link 27 at movable pivot point 226. All other features of the system in this embodiment are the same as described in the embodiment of FIG. 1.
In operation, when bottle 23 is less than full, platform 24 and control link 27 are in their upward positions, as described earlier. This upward position of control link 27 causes control arm 225 to hold valve 224 in the open position. Water in heat exchange tube 220 is cooled by the presence of ice in bin 18 and flows downward in convective flow, through the open valve 224 and return pipe 223, to warming coil 221. Since warming coil 221 is located in the warmer room environment, the returning water is warmed, and then rises, flowing through supply pipe 222 to heat exchange tube 220 to supply more heat for ice melting, thus establishing a continuous convective flow and melting function. A raised section 227 of supply pipe 222 helps to establish a convective flow by preventing backflow. Standpipe 228 helps maintain water level in the convection loop by allowing for expansion. The melting function continues until bottle 23 is full, at which time platform 24 and control link 27 move downwards causing valve 224 to move to the closed position. This interrupts the convective flow, causing the melting function to cease. The use of control arm 225, to couple movements of platform 24 and valve 224, could be replaced by other practical, alternative means of achieving such a coupling. As an additional alternative precaution, for higher overall efficiency, a similar valve might be added in supply pipe 222 and coupled in the same manner.
FIG. 3 illustrates an embodiment similar to the embodiment of FIG. 2 except that the system condenser 230 is specifically air cooled. Condenser fan 231 draws ambient air, warmed by the room environment, over the tubes of condenser 230 where it is warmed further and passes over warming coil 221. This arrangement provides more effective heating by warming coil 221. In this arrangement it is necessary that the system condenser be mounted in a location below the ice bin 18; accordingly, a longer discharge line 232 and longer liquid line 233 are employed.
From the foregoing description it will be appreciated that the invention makes available a novel method and apparatus for efficiently melting ice collected in a bin as part of an ice-forming process in which the ice is formed as purified ice pieces from an unpurified source of water, and wherein the purified ice is melted to provide a supply of purified water.
Having described preferred embodiments of a new and improved ice maker and water purifier with controlled condensing temperature in accordance with the present invention, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as defined by the appended claims. | A refrigeration system employed as an icemaker, in which part of the ice so produced is stored in a bin, and in which, part of the ice is then melted to provide a supply of purified water in a container. In one embodiment convection flow of air conveys heat from the ambient room environment to the bottom of the ice bin to achieve this melting. In a second embodiment a convection flow of water is employed for this purpose. Controls are provided to automatically control melting, to maintain a predetermined level in the purified water container. | 5 |
BACKGROUND OF THE INVENTION
[0001] The present invention pertains to vibratory rollers for soil and backfill compaction and, more particularly, to an improved shaft assembly for a vibratory roller.
[0002] Vibratory rollers are well known in the utility and road construction industries for compacting backfill and other fill materials. Typically, such rollers include a large cylindrical roller drum attached to a piece of off-road equipment for movement over the surface to be compacted. A vibratory exciter shaft is mounted axially inside the drum, journaled to rotate independently of the drum and driven at high speed to impart vibratory motion to the drum to facilitate compaction. A vibratory roller may also be mounted with a scraper blade, such as shown in the apparatus of U.S. Pat. No. 5,062,228.
[0003] As shown in the above-identified patent and typical of the prior art, the exciter shaft comprises a solid steel shaft to opposite ends of which are welded aligned eccentric weights. It is also known to fasten the eccentric weights to the solid shaft with bolted connections. The opposite ends of the solid shaft are journaled in the end walls of the drum utilizing a bearing and seal arrangement. It has been found, however, that a solid steel eccentric shaft, having a typical diameter of about 3 inches (about 75 mm), is subject to excessive deflection at high speed rotation in the unsupported center of the shaft. This deflection is transmitted to the bearings and end seals, resulting in excessive misalignment, overheating, leakage and eventual failure of both the seals and bearings. Also, bolted connections are less reliable and more susceptible to failure then welds.
[0004] In accordance with the present invention, the prior art solid steel shaft is replaced by a hollow shaft of improved stiffness, yet lower weight, with an improved mounting for the eccentric weights and a lubrication system that is more effective and efficient.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a shaft assembly for a vibratory roller of the type having a roller drum enclosed by annular end walls on opposite axial ends of the drum, the shaft assembly comprising a cylindrical tubular shaft, eccentric weights mounted on the interior wall of the tubular shaft and equally distributed axially therewithin, a pair of shaft ends that enclose the opposite axial ends of the tubular shaft, each shaft end including a reduced diameter stub shaft that carries a bearing and seal journaled in the drum end wall for rotation relative thereto.
[0006] In the preferred embodiment, a tubular shell encloses the tubular shaft and is operatively attached at opposite ends to the end walls of the roller drum for rotation therewith. The tubular shell and the tubular shaft define a sealed annular oil chamber. In the preferred construction, each drum end wall has mounted centrally therein an end cap that surrounds one of the stub shafts and provides the journaled mounting for the bearing and seal. The end cap includes a cylindrical outer surface portion that is adapted to be received in a counterboard end of the tubular shell for attachment thereto. One of the stub shafts is provided with a drive connection for transmitting driving rotation to the tubular shaft.
[0007] In the preferred embodiment, the eccentric weights comprise a solid semi-cylindrical weight on each end of the interior of the tubular shaft adjacent the shaft ends, the weights positioned in axial alignment within the tubular shaft. Each of the eccentric weights has a diameter equal to the ID of the tubular shaft. Preferably, oil distribution elements are attached to the OD of the tubular shaft and oriented with respect to the direction of shaft rotation to direct oil in the oil chamber axially toward the bearings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The drawings illustrate the best mode presently contemplated of carrying out the invention.
[0009] In the drawings:
[0010] FIG. 1 is a perspective view, partly exploded and partly in section, showing the shaft assembly of the present invention.
[0011] FIG. 2 is an enlarged sectional view through the drum of a vibratory roller showing the mounting of the shaft assembly of the present invention.
[0012] FIG. 3 is a sectional view taken on line 3 - 3 of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] Referring to FIGS. 1 and 2 , a roller drum 10 for a vibratory roller has a cylindrical outer wall 11 enclosed at opposite ends by annular end walls 12 . An arrangement (not shown) for mounting the roller drum 10 to a carrying vehicle, such as a tractor, is connected to the end walls 12 . Such a mounting arrangement is shown, for example, in above-identified U.S. Pat. No. 5,062,228 which is incorporated by reference herein.
[0014] A vibratory shaft assembly 13 of the present invention is mounted on the axis of the drum 10 between the end walls 12 . The shaft assembly 13 includes a cylindrical tubular shaft 14 which, in one embodiment, is made from a steel tube having an OD of 6 inches (about 150 mm) and a wall thickness of 0.25 inch (about 6 mm). This thin wall tubular shaft 14 replaces the solid steel shaft used in the prior art, as shown in the above identified patent.
[0015] The opposite ends of the tubular shaft 14 are closed with a pair of shaft ends 15 which are machined from circular bar stock. The shaft ends 15 are welded to the ends of the tubular shaft 14 , but prior to attachment, a semi-cylindrical eccentric weight 16 is welded to the ID of the tubular shaft at each end. Each eccentric weight 16 has a diameter that corresponds to the ID of the tubular shaft 14 and is positioned to lie immediately adjacent the inside face 17 of a shaft end 15 . Each shaft end 15 includes a reduced diameter stub shaft 18 on which is mounted the inner race of a bearing 20 and the inner surface of a rotary seal 21 .
[0016] The tubular shaft 14 is enclosed by a tubular shell 22 that is welded at opposite axial ends around the periphery of circular openings 23 in the drum end walls 12 . The tubular shaft 14 , including the shaft end 15 , bearing 20 and seal 21 , is mounted for rotation within the tubular shell 22 by an end cap 24 . The mounting assembly to be described is essentially identical for both ends of the shaft assembly 13 . Thus, each end cap 24 has a cylindrical outer surface 25 by which the end cap is received in a counterbore 26 in the end of the tubular shell 22 . An O-ring seal 27 seats in a groove in the cylindrical outer surface 25 to prevent leakage of oil past the shell 22 and end cap 24 interface. Each end cap 24 also includes an outer mounting flange 28 by which the end cap is attached to the drum end wall 12 with a circular pattern of mounting bolts 30 . The ID of the end cap 24 is provided with an inside counterbore 31 which receives the outer race of the bearing 20 . The bearing is held in place with a retaining ring 32 . The end cap also has an interior flange 33 that receives the outer face of the seal 21 which, in turn, is enclosed and held on the surface of the stub shaft 18 by a breather cap 34 . The breather cap is used only on one axial end of shaft assembly, the end cap 24 at the opposite end being tapped for attachment of the drive pulley (not shown) or the like used to impart rotary motion to the tubular shaft 14 .
[0017] Thus, the cylindrical tubular shaft 14 and eccentric weights 16 mounted therein are journaled by the shaft ends 15 for rotation inside and relative to the tubular shell 22 . The thin annular space 35 between the OD of the tubular shaft 14 and the ID of the tubular shell 22 is partially filled with oil to provide lubrication for the bearings 20 . The main seals 21 and O-ring seals 27 retain the oil within the annular space 35 . Oil distribution elements 36 are welded to the OD of the tubular shaft 14 to assist in lubricating the bearings 20 . The annular space 35 is filled with oil only to a depth of about ⅓ the diameter of the tubular shell 22 . The oil distribution elements 36 comprise short lengths of bar stock or key stock and are oriented with respect to the direction of shaft rotation to direct oil in the annular space 35 toward the bearings 20 .
[0018] In addition to the preferred embodiment described above, the tubular shaft 14 could be mounted in a manner in which it extends through the end walls 12 of the roller drum 10 and journaled for rotation relative to the drum on external bearings. The external bearings could be attached, for example, to the plate on the carrying vehicle which also mounts the drum 10 for rotation. Such a plate or “spider” be shown as item 16 in U.S. Pat. No 5,062,228. With bearings mounted externally of the drum 10 , the tubular shell 22 and the end caps 24 of the preferred embodiment may also be eliminated because an oil chamber 4 internal lubrication of the bearings would no longer be needed. Nevertheless, a fully functional alternative construction utilizing the hollow cylindrical shaft 14 and internally mounted eccentric weights 16 may still be used. With respect to the eccentric weights, instead of the two semi-cylindrical weights 16 welded to the interior of the tubular shaft 14 , alternate constructions, such as a single piece of bar stock welded to the inner wall of the shaft, could also be used.
[0019] By replacing the solid steel shaft of the prior art with the tubular shaft 14 of the present invention, shaft deflection has been reduced considerably and, as a result seal movement and bearing misalignment are also reduced. In addition, the mounting of the eccentric weights 16 inside the tubular shaft 14 (rather than on the OD of the solid shaft of the prior art) minimizes the disturbance of oil in the oil chamber 35 , thereby reducing foaming and maintaining lower operating temperatures in the oil. The vibratory shaft assembly 13 of the present invention provides a marked improvement in operation, a lighter weight assembly, and substantially improved bearing and seal life. | An eccentric shaft assembly for a vibratory roller utilizes a cylindrical tubular shaft that considerably reduces the weight of the assembly, decreases substantially oscillatory shaft deflection during rotation and thereby improves bearing and seal life. The eccentric weights are mounted on the interior of the tubular shaft, thereby simplifying manufacture and providing a smoother operation. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to electronic rectifier circuits and, more particularly, to single phase circuits having a low input current distortion.
A basic single phase rectifier circuit includes a full wave bridge for rectifying an AC input voltage and a circuit branch including the series connection of an inductor and a capacitor which is connected across the output terminals of the bridge. The capacitor voltage is delivered to a load. Efficient conversion of single phase AC to DC voltage is hampered by non-sinusoidal input currents which result from the operation of such circuits. If the inductance of the inductor is very large, the input current of the bridge rectifier approximates a square wave. For more practical values of inductance, the input current consists of the sum of a square wave and a lagging fundamental component of the current. Such input currents have a very large total harmonic distortion, which causes the input power factor to be low, limiting the power available from a given wire or protective device. The distorted input currents will cause distortion in the line voltage. Ideally, the input current should look like the input voltage, so that the rectifier appears as a linear, resistive load to the rest of the power system, yielding unity input power factor and an ideal current crest factor of 1.414.
To reduce the input current distortion of the basic rectifier circuit described above, a boost converter can be added by placing a diode between the inductor and capacitor and connecting a switching device across the series connection of the diode and capacitor. The switching device can be turned on and off to develop a DC voltage on the capacitor which exceeds the peak of the AC input- voltage. With the switch off, the rectified output of the bridge is connected to the capacitor through the diode. The switch is turned on to increase current through the inductor and turned off to decrease current through the inductor. Turning off the switch dumps the energy from the inductor to the capacitor. For 60 Hz inputs, the switch may be operated at a rate of 40 kHz to 75 kHz, thereby providing precise control of the input current to match the input voltage waveform This is a switching rate of about 1000 times the input line frequency
For AC systems operating at high line frequencies, such as 20 kHz, this high frequency ratio is not practical. For high efficiency, a ratio of 10 times the line frequency would be more practical. A lower switching frequency requires the use of a larger inductor to keep the ripple current down to a reasonable level. The larger inductor causes a cross-over distortion problem. Near zero cross-over, there is no input voltage available to drive current into the inductor The current lags the input voltage causing a notch effect in the current waveform with low order harmonics which are difficult to filter.
It is therefore desirable to devise a single phase rectifier circuit which operates with relatively low input current distortion but operates at a relatively low switching rate such that it is practical for use in relatively higher frequency AC systems.
SUMMARY OF THE INVENTION
Single phase rectifier circuits constructed in accordance with the present invention produce a full wave rectified voltage by rectifying an AC input voltage and coupling the rectified voltage to a filter capacitor through an inductor. A switching circuit is provided for switching the sum of the rectified voltage and the voltage on the capacitor across the inductor to drive current through the inductor thereby storing energy in the magnetic field of the inductor. Turning off the voltage to the inductor transfers this energy to the capacitor, thereby boosting the voltage on the capacitor. In the preferred embodiment, the switching circuit is a half bridge boost converter.
This invention encompasses both rectifier circuits constructed as discussed above and the method of power factor improvement performed by those circuits. The invention utilizes the capacitor voltage to drive inductor current when the magnitude of the rectified voltage is insufficient to perform this function This permits a reduction in input current distortion with a relatively low switching frequency. Such circuits have reduced losses at high AC line frequencies and can be implemented in a voltage feedback loop of a voltage regulator to provide control of the rectified output voltage magnitude.
DESCRIPTION OF THE DRAWINGS
The invention will become more readily apparent from the following description of the preferred embodiment thereof, shown by way of example only, in the accompanying drawings, wherein:
FIG. 1 is a simplified schematic diagram of a rectifier circuit constructed in accordance with one embodiment of the present invention;
FIGS. 2, 3, and 4 are waveforms illustrating the operation of the circuit of FIG. 1; and
FIGS. 5A and 5B are schematic diagrams of one implementation of the circuit of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, FIG. 1 is a simplified schematic diagram of a single phase, rectifier circuit constructed in accordance with one embodiment of the present invention. An AC input voltage is provided by an external source 10 to input terminals 12 and 14 of a full wave rectifier bridge BR1. This results in a full wave rectified voltage at the output terminals 16 and 18 of the bridge. A circuit branch comprising the series connection of an inductor L1 and a diode CR1 is electrically connected between a first bridge output terminal 16 and a load terminal 20. An output capacitor C1 is connected between the load terminals 20 and 22. A pair of controllable switching devices, in the form of field effect transistors Q1 and Q2, and a pair of diodes, CR1 and CR2, are connected to form a half bridge boost converter circuit. A control circuit 24 senses the input current to the bridge via current transformer 26 and controls the operation of transistors Q1 and Q2 in a manner which reduces the input current distortion.
With both Q1 and Q2 off, the rectified voltage from bridge BR1 is connected to the load 28 through diodes CR1 and CR2. With both Q1 and Q2 on, the DC voltage across capacitor C1 is connected in series with the bridge output voltage to increase the current through inductor L1 at a faster rate by applying this increased voltage.
FIG. 2 is a waveform 30 of the input current for the circuit of FIG. 1. Note that there is no notch at zero current to cause low order harmonic distortion. The waveform illustrated in FIG. 2 has about 1.5% 3rd harmonic and 1.2% 5th harmonic with a total harmonic distortion of about 7.3%. If a simple low pass LC filter tuned to the 7th harmonic is added to the input of the circuit of FIG. 1, the input current distortion is reduced even further as illustrated by waveform 32 of FIG. 3. Waveform 32 has a total harmonic distortion of about 4.1%.
The relatively low distortion input current waveforms of FIGS. 2 and 3 were obtained with a switching frequency of about 12 times the fundamental AC input frequency. To improve efficiency, it is desirable to reduce the switching frequency even further. Waveform 34 of FIG. 4 shows the results obtained with a modification in the operation described above. For this waveform, the drive signal to transistor Q1 or Q2 is disabled when there is sufficient voltage at the bridge output to drive the inductor current. The circuit then reverts to the normal boost converter configuration in which only one transistor is switched. This lowers the voltage applied to the inductor and eliminates the extra switching points at the top of the current waveform. FIG. 4 shows about 8 switches per cycle. The unfiltered current waveform has a total harmonic distortion of about 6.6% compared to about 7.3% for FIG. 2. Better performance is obtained with a lower switching frequency by using this switched mode of operation.
FIGS. 5A and 5B are schematic diagrams of a circuit which was built in accordance with this invention to prove the performance and obtain the current waveforms illustrated in FIGS. 2, 3, and 4. For clarity, lines connecting FIGS. 5A and 5B are labeled a, b, c, d, e and f. AC power from an external source 10 is delivered to the circuit through a variable autotransformer T1 and an isolation transformer T3. A low pass filter 38, comprising resistor R1, inductor L2 and capacitor C2, is inserted between t output of transformer T3 and bridge BR1. Circuit 36, comprising variable autotransformer T2, isolation transformer T4 and bridge rectifier BR2, produces a separately adjustable and isolated reference voltage at point 40. An input current sensing circuit 42 comprising bridge BR3 and resistor R2, receives a current signal representative of the input current to bridge BR1 from current transformer 26 and produces a voltage representative of that input current at point 44. A comparator circuit 46 comprising amplifier U1, and resistors R3, R4, R5, R6, and R7, compares the voltages at points 40 and 44 and produces a control signal at point 48. This control signal is utilized by a drive circuit 50 comprising an isolated half bridge driver U2 (e.g. IR2110) , diode CR3, capacitor C4, and resistors R8 and R9, to control the operation of transistors Q1 and Q2. In the comparator circuit, resistors R6 and R7 can be varied to control the hysteresis of the control circuit to reduce the number of switching points in the waveform.
A switching mode control circuit 52 comprising amplifier U3, and resistors R10, R11, R12 and R13 allows the circuit of this invention to be operated in the normal booster, half bridge, or switched modes described above. When switch S1 is connected to terminal 54, the noninverting input of amplifier U3 is grounded, causing its output to be low. This disables the drive for transistor Q1 so the circuit operates as a normal booster. With S1 connected to terminal 56, the inverting input of amplifier U3 is grounded, forcing the output high. This causes the drive for transistor Q1 to switch at the same time as the drive for transistor Q2, causing half bridge operation. With S1 connected to terminal 58, amplifier U3 switches low when the reference voltage exceeds a predetermined magnitude, for example, 72 volts for a 115 volt 400 Hz AC input. This causes the circuit to operate in the switched mode as described above, changing from half bridge to normal booster operation during the cycle. The circuit can also be operated as a normal rectifier by removing control power or adjusting the reference voltage at point 40 to zero.
With the controls activated, the output voltage can be adjusted up to 200 volts DC for a 115 volt AC input. When operated as a closed loop system, the reference input would be derived from a separate winding on the power transformer, rectified, and multiplied by a DC voltage error signal, resulting in control of the output DC voltage as well as input current distortion.
It should now be apparent that this invention controls input current distortion of a single phase rectifier, to improve the power factor, with the lowest possible switching frequency This reduces losses at high line frequencies. The circuit can also be implemented in a voltage feedback loop to provide control of the rectified output voltage. Although the present invention has been described in terms of what is presently to be is preferred embodiment, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention. It is therefore intended that the appended claims cover such changes. | A single phase rectifier circuit produces a full wave rectified voltage by rectifying an AC input voltage, couples the rectified voltage to a filter capacitor through an inductor, and repeatedly switches the sum of the rectified voltage and the voltage on the capacitor across the inductor, thereby reducing input current distortion and improving the power factor of the circuit. When the rectified voltage is of a sufficient magnitude to drive current through the inductor, switching of the capacitor voltage across the inductor can be eliminated. The switching function is performed by a half bridge boost converter. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to garden tools; and, more particularly, to a hydraulically actuated tool which utilizes water under pressure from a garden hose to actuate a cutting element to thereby cut branches or the like.
2. Description of the Prior Art
Various types of garden tools are known for cutting branches or the like. Such tools do not work well on branche over a particular diameter. Other tools require a great forc to cut large diameter branches, such force being beyond that of many people, such as women and children. Still other branch cutting tools wear quickly or the blades are knocked out of alignment in attempting to cut branches over a certain diameter. All such tools require the grasping of a pair of handles to move two blades together to cut a branch between the blades.
There is a need for a branch cutting tool which can cut quickly and easily branches of a relatively large diameter. Such a tool should provide a force independent of that of the operator to effect such cutting.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a hydraulically actuated branch cutting tool.
It is a further object of this invention to provide a cutting tool which can apply a cutting force to branches or the like independent of the strength of the operator.
It is still another object of this invention to provide a cutting tool which utilizes the ready availability of water pressure from a garden hose to cut branches or the like.
It is a further object of this invention to carry out the foregoing objects in an economical and inexpensive manner.
These objects and others are preferably accomplished by providing a housing having a piston therein, a piston shaft connected to the piston and a branch cutting blade at the end of the shaft. The blade is movable in a guide for receiving a branch between the guide and the blade. A water inlet is provided into the piston controlled by a hand grip. When water is introduced under pressure into the inlet and the hand grip is actuated, the blade is moved into contact with the guide to thereby cut a branch trapped therebetween.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a vertical, partly cross-sectional, view of a hydraulically actuated garden tool in accordance with the invention;
FIG. 2 is a view taken along lines II--II of FIG. 1;
FIG. 3 is a perspective view of the tool of FIG. 1 about to be actuated to cut a branch;
FIG. 4 is a perspective view similar to FIG. 2 after actuation to cut the branch; and
FIGS. 5 through 7 are vertical views of portions of the tool of FIG. 1 showing various modifications thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawing, a garden tool 10 is shown having a main housing 11 which may be cylindrical and sealed at each end by end walls 12,13. A conventional piston garden hose fitting 14 is provided having a fixed hand grip 15, a movable actuating lever 16 and a threaded portion 17 having threads 18 threadable into a threaded opening 19 in wall 12.
The interior of portion 17 is conventional having a piston shaft 20, a piston 21, a coil spring 21' normally biasing piston 21 to the right in FIG. 1, and end wall 22 with shaft 20 extending therethrough and terminating in an enlarged end 23. The other end of the shaft 20 extends out of portion 17 and through a slot in lever end 24 and terminates in a threaded nut 27 threaded on end 28 of shaft 20 so as to make the travel of shaft 20 adjustable. Lever 16 is pivotally connected via pivot pin 25 to a bracket 26 secured to grip 15 and portion 17. A stop flange 29 is fixedly secured to lever 16 and overlies nut 27.
It can be appreciated that moving lever 16 in the direction of arrow 30 moves lever end 24 in the opposite direction which pulls nut 27 and thus shaft 20 via piston 21 to move shaft 20 away from opening 31 in wall 22 to thus permit water introduced into grip 14 to exit out of opening 31 and into housing 11.
The foregoing has described a conventional pistol hose fitting well known in the art and which forms no particular part of my invention other than in the environment claimed. Obviously, other hose-type grips may be substituted, as long as fluid emitting therefrom can be controlled.
A conventional garden hose 81 having a threaded fitting 32 may be threaded into threaded opening 33 of hand grip 15.
End walls 12,13 and housing 11 may be of any suitable rigid material, such as polyvinyl chloride or the like. A piston 34, which may be any suitable material, such as nylon, is slidably mounted in housing 11 of a configuration, such as cylindrical, related to the inner configuration of housing 11. A peripheral groove 35 is provided on piston 34 for receiving a resilient O-ring 36 therein. Piston 34 has a centrally located threaded aperture 37 extending axially thereto for receiving the threaded end 38 of a rod 39. Rod 39 extends out of housing 11 in an axial direction as will be discussed. A bleed valve 40 is provided on piston 34 having a shaft 41 loosely disposed in an aperture 42 through piston 34 off-center from aperture 37. Shaft 41 terminates out of piston 34 in an enlarged head 43. Travel of valve 40 is limited by a spring 44 biasing a ball 45 selectively entering grooves 46,47 in shaft 41 as will be discussed. A coil spring 48 encircles rod 39 between piston 34 and end wall 13. Coil spring 48 encircles a boss 49 on piston 34 and guide rod 80 of housing 50 extending through end wall 13. Housing 50 may also be of any suitable rigid material, such as plastics, eg polyvinyl chloride. Housing 50 is preferably a tube cemented in opening 51 in end wall 13 and containing guiding rod 39 therein.
A port 52 is provided in end wall 13 communicating with both the interior of housing 11 and the exterior thereof. Portion 53 of port 52 may be internally threaded for receiving an elbow fitting 54 therein, for reasons to be discussed. Guide rod 50 is part of housing 80.
If desired, filter 55 may be provided in housing 11 and suitable seals, such as a washer 56 may be provided at end wall 11 at threads 18.
Housing rod 50 extends out of housing 11 and is threadably received in a sleeve or collar 57 of a branch receiving hook 58. Hook 58 includes an elongated portion 59 welded or otherwise secured to collar 57 extending away from housing 11 to a U-shaped hook portion 60. Plate 59,60 may be one-piece, if desired, or two abutted secured portions.
As shown in FIG. 2, portions 59,60 are comprised of two spaced sections forming a slot 61, the sections being retaine in spaced relationship by spaced welds 62 or the like.
Rod 39 extends through housing 50 in collar 57 and, at its terminal end 63, has a cross-pin 64 in a suitable aperture therein extending through a like aperture in a branch cutting blade 65. Blade 65 includes an integral guide portion 66 adapted to ride in the slot 61 and a sharpened generally semi-circular end 67. As will be discussed, end 67 is adapted to move into the portion of slot 61 at hook portion 60 when tool 10 is actuated. Finally, a stop nut 68 is threaded onto the terminal end of housing 50 to provide a stop for the rear or non-cutting end 69 of blade 65.
In operation, as shown in FIG. 3, hose 81 is connected to grip 15 and a flexible hose 70 is connected to fitting 54 and may be of any suitable length and configuration. Hose 70 is used to deflect water away from tool 10 during operation. A tree branch 71 or the like is disposed in hook portion 60 in the path of travel of blade 65. The water is turned on and pistol grip fitting 14 is actuated, as heretofore described, which introduces water under pressure into housing 11 on the rear of piston 34 closing valve 40 (FIG. 1 position) and moving piston 34 against the bias of spring 48. This moves rod 39, coupled to piston 34, which, in turn, moves blade 65 in the slot 61 of hook portion 60 thus chopping off branch 71 caught between blade 65 and hook portion 60 (FIG. 4). Any water leakage past piston 34 flows out fitting 54 and through hose or tube 70 away from the operator. Release of lever 16 stops the flow of water to piston 34 and spring 48 biases piston 34 back to the FIG. 1 position. When the shaft 41 of valve 40 hits end wall 13, it opens the valve with ball 45 now entering groove 47 to stop the travel thereof. This permits spring 48 to bias piston 34 back to the FIG. 1 position. The extent of travel of piston 34 is shown as x in FIG. 1. Of course, piston 34 also abuts against rod 50 to stop its travel. Valve 40 of course closes when head 43 contacts end wall 12. Hose 70 may be coupled to housing 31, if desired. Fitting 54 may be turnable in any desired direction. In place of flexible tubing 70, a rigid tube 72 may be provided having a threaded end 73 threading on fitting 54 for directing the water in a predetermined direction toward or away from tool 10. Also, as shown in FIG. 6, a rigid spraying attachment 74 may be threaded via threaded end 75 to fitting 54 with water spraying out of sprayer 76 to disperse the excess water over a wide area. The amount and size of holes in sprayer 76 may be varied to give either a spraying or misting effect. Also, a handle 77 may be provided fixedly secured to housing 11 (or threaded in suitable threaded openings therein) to provide a grip for the operator and counterbalance the forces acting on tool 10. Handle 77 may also be foldable, if desired.
It can be seen that I have disclosed a tool which can be used to take advantage of the easy availability and tremendous force of water pressure to cut branches or twigs or the like. In fact, the tool of my invention can be actuated with only 30 pounds of pressure.
The design of this device includes several safety features, the most important of which is the fact that the combined portions 59, 60 act as a blade sheath to cover the exposed area of the blade during time of acutation. It is difficult for a finger to be severed or cut unless it is actually placed within the jaw of this hook-shaped sheath.
Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A hydraulically actuated garden tool including a housing, a piston in the housing and a shaft connected to the piston extending out of the housing and terminating in a cutting blade. A guide is provided receiving the blade therein when the piston is actuated. A water inlet, controlled by a handle, is provided leading into the housing so that the introduction of water under pressure into the housing moves the piston, when the handle is actuated, to move the blade into the guide to cut a branch trapped therebetween. | 0 |
PRIOR APPLICATIONS
This application claims priority of U.S. Utility application Ser. No. 12/235,480 filed Sep. 22, 2008 which claims priority of U.S. Provisional Application 60/974,348 filed Sep. 21, 2007. Both applications are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates generally to the field of door frames. More specifically the present invention relates to a frame, its kit, and a method for installing an expandable door frame for conventional storm doors within the opening bounded by a door jamb and a header.
SUMMARY OF THE INVENTION
The present invention is an expandable frame for a storm door. The frame is mounted onto the header and door jamb in an entrance. The expandable feature of the frame eliminates the need to affix U-shaped brackets along the sides of a storm door when the storm door is smaller than the height or width of the entry. The frame includes an expandable header assembly, an expandable lock-side assembly and a hinge-side piece. The header assembly includes a frame mount and a header stop. The frame mount is mounted onto the underside of an entry-way header and the header stop is then attached to the frame mount. The separation between the frame mount and the header stop is adjustable. The hinge-side piece is mounted vertically along a door jamb on one side of the entrance. The lock-side assembly includes a lock-side stop and a frame mount. The frame mount for the lock-side assembly is mounted vertically onto a door jamb generally parallel to the hinge-side piece. The lock-side stop is then attached to the frame mount. The lock-side assembly, like the header assembly, is adjustable.
It is an aspect of the present invention to provide an expandable frame and its kit that is easily installed in an entrance and adjusted, so that the dimensions of the entry will accommodate a storm door.
It is another aspect of the present invention to provide a method of installing an expandable frame assembly that will allow the user to adjust the dimensions of the opening in an entry to accommodate a storm door having smaller dimensions than the height and width of the opening.
It is yet another aspect of the present invention to provide an expandable door frame having the advantageous characteristics mentioned above, which is simple in structure and economical in manufacture, and staunch, durable and reliable to effectively provide an adequate frame around the entry of a storm door.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion taken in conjunction with the following drawings, in which:
FIG. 1 is a left-side elevational view of the header assembly of the expandable frame of the present invention as viewed along line I-I in FIG. 9 ;
FIG. 2 is a left-side elevational view of the header assembly of the expandable frame of the present invention as viewed along line II-II in FIG. 10 ;
FIG. 3 is a view from above the lock-side assembly of the expandable frame of the present invention as viewed along line III-III in FIG. 7 ;
FIG. 4 is a view from above the lock-side assembly of the expandable frame of the present invention as viewed along line IV-IV in FIG. 8 ;
FIG. 5 is a view from above the hinge-side piece of the expandable frame of the present invention as viewed along line V-V in FIG. 6 ;
FIG. 6 is a fragmentary perspective view of the expandable frame of the present invention showing the hinge-side piece;
FIG. 7 is a fragmentary perspective view of the expandable frame of the present invention showing the lock-side assembly in the closed position.
FIG. 8 is a fragmentary perspective view of the expandable frame of the present invention showing the lock-side assembly in the open position.
FIGS. 9 a and 9 b are fragmentary top perspective views of the expandable frame of the present invention showing the header assembly in the closed position.
FIG. 10 is a fragmentary top perspective view of the expandable frame of the present invention showing the header assembly in the open position.
FIG. 11 is a fragmentary bottom perspective view of the expandable frame of the present invention showing the header assembly in the closed position.
FIG. 12 is a fragmentary bottom perspective view of the expandable frame of the present invention showing the header assembly in the open position.
FIG. 13 is a plan view of a prior art U-bracket system
FIG. 14 is a perspective view of the header-stop, lock-side stop, and hinge-side piece of the present invention as seen from the outside of a house
FIG. 15 is a perspective view of the header-stop, lock-side stop, and hinge-side piece of the present invention as seen from the inside of a house
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Reference is now made to the drawings, wherein like characteristics and features of the present invention shown in the various FIGURES are designated by the same reference numerals.
The expandable door frame of the present invention includes a header assembly 20 , a hinge-side piece 45 , and a lock-side assembly 60 . The expandable door frame may be made of any material suitable to support a door within an entrance, depending on the location, weight, and type of door.
FIGS. 1 and 2 depict a header assembly 20 . The header assembly 20 comprises a frame mount 21 and a header stop 22 . The frame mount 21 has a bottom surface 23 integrally connected to two generally parallel side walls 24 that are generally perpendicular to the bottom surface 23 . The frame mount 21 is mounted onto the header of an entrance, such that the bottom surface 23 is generally flush with the underside of the header. The frame mount 21 preferably has at least one mounting hole 25 in which a mounting screw 26 is inserted to attach the frame mount 21 to the underside of the header. The bottom surface 23 of the frame mount 21 is optionally shaped to include at least one groove 27 . The grooved bottom surface reduces the amount of material needed to construct the frame mount without depriving the frame mount of the strength and rigidity needed to support the header stop. The frame mount 21 also includes additional holes to receive an adjustment screw 28 and a locking screw 29 .
Upon mounting the frame mount 21 onto the underside of the header, an adjustment screw 28 is inserted through the adjustment screw hole 30 in the frame mount 21 and into the header. The header stop 22 is then mounted onto the frame mount 21 . The header stop 22 includes a top surface 31 integrally connected to two generally parallel expander walls 32 , a door stop 33 , and a lip 34 . When the header stop 22 is mounted onto the frame mount 21 , the two parallel side walls 24 of the frame mount 21 are in sliding contact with the two parallel expander walls 32 of the header stop 22 , the lip 34 extends in a direction generally perpendicular to the expander walls 32 , and the top surface 31 of the header stop 22 rests against the head of the adjustment screw 28 . The header stop 22 includes an adjustment screw hole 35 in registry with the adjustment screw 28 and a locking screw hole 36 in registry with the locking screw hole 37 in the frame mount 21 . The head of the adjustment screw 28 is larger than the diameter of the adjustment screw hole 35 which enables the header stop 22 to rest on the head of the adjustment screw 28 .
The header assembly 20 expands between a closed position depicted in FIG. 1 and an open position depicted in FIG. 2 . The distance between the top surface 31 of the header stop 22 and the bottom surface 23 of the frame mount 21 depends on the depth in which the adjustment screw 28 is inserted into the header. In FIG. 1 , the adjustment screw 28 is inserted into the header to a depth that allows the top surface 31 of the header stop 22 to contact the two parallel side walls 24 of the frame mount 21 . In FIG. 2 , the adjustment screw 28 has not penetrated the header as deep as the adjustment screw depicted in FIG. 1 , thus the header assembly 20 is expanded to the open position because the top surface 31 of the header stop 22 rests on the head of the adjustment screw 28 . The adjustment screw hole 35 in the header stop 22 provides access to the adjustment screw 28 to vary the depth of the adjustment screw 28 in the header. When a user has selected the appropriate depth for the adjustment screw, the header stop 22 is locked in place by inserting a locking screw 29 through the locking screw holes 36 , 37 in the header stop 22 and the frame mount 21 .
The door stop 33 of the header stop 22 optionally includes a weather stripping groove 38 . The header stop 22 also includes a lip 34 that shields water or other elements from entering the top of a storm door. The depth of the adjustment screw 28 should be set so that the header assembly 20 has expanded to a position that allows a storm door to pass under the lip 34 and contact the door stop 33 when closed. The header stop 22 optionally includes a clearance hole 39 in registry with the mounting screws 26 for the frame mount 21 to provide quick access to the mounting screws 26 without having to remove the header stop 22 . The header stop 22 also optionally includes a cover groove 40 in which the adjustment screw holes 35 , locking screw holes 37 , and clearance holes 39 reside. The cover groove 40 accepts a cover 43 , as shown in FIG. 12 , in order to conceal the various screws inserted in each hole and provide a more aesthetically pleasing look for the header assembly 20 when installed. The header assembly 20 may optionally include a notch 41 created by removing a section of the door stop 33 , so that the bottom surface 42 of the header stop 22 can rest on the hinge-side piece 45 .
Referring now to FIGS. 5 and 6 , the hinge-side piece 45 comprises a mounting surface 46 , a hinge section 47 , and a door stop 48 . The hinge-side piece 45 is mounted vertically onto a door jamb of an entrance on the side of the entrance that coincides with the hinge on a door that is mounted on the door frame. The hinge-side piece 45 is mounted so that the mounting surface 46 is generally flush with the door jamb and preferably has at least one mounting hole 49 in which a mounting screw 51 is inserted to attach the hinge-side piece 45 to the door jamb. The mounting surface 46 of the hinge-side piece 45 is optionally shaped to include at least one groove 50 . The grooved surface reduces the amount of material needed to construct the hinge-side piece without depriving the hinge-side piece of the strength and rigidity needed to support a door.
Unlike the header assembly 20 and the lock-side assembly 60 , the hinge-side piece 45 is not adjustable. The hinge-side piece 45 includes a hinge section 47 that can receive a pin, such as a pin inserted into a piano hinge, which are typically used to mount storm doors. The door stop 48 for the hinge-side piece 45 also optionally includes a weather stripping groove 52 .
FIGS. 3 and 4 demonstrate a sectional view of the lock-side assembly 60 . The lock-side assembly 60 comprises a frame mount 21 , similar to the header assembly 20 , and a lock-side stop 61 . The frame mount 21 is similar to the frame mount 21 for the header assembly 20 , except that the lock-side assembly 60 is mounted vertically on the door jamb, generally parallel to the hinge-side piece 45 on the opposite side of the entrance. This side of the entrance coincides with the lock-side of a door that is mounted on the door frame. The bottom surface 23 of the frame mount 21 for the lock-side assembly 60 is mounted generally flush with the surface of the door jamb. The frame mount 21 preferably has at least one mounting hole 25 in which a mounting screw 26 is inserted to attach the frame mount 21 to the door jamb.
Similar to the header assembly, upon mounting the frame mount 21 onto the door jamb, an adjustment screw 62 is inserted through an adjustment screw hole 30 in the frame mount 21 and into the door jamb. The lock-side stop 61 is then mounted onto the frame mount 21 . The lock-side stop 61 includes a top surface 63 integrally connected to two expander walls 64 , and a door stop 65 . One of the expander walls 64 can be optionally curved to resemble the hinge section 47 of the hinge-side piece 45 to provide a more symmetrical and aesthetically pleasing look to the door frame when installed.
When the lock-side stop 61 is mounted onto the frame mount 21 , the two side walls 24 of the frame mount 21 are in sliding contact with the two expander walls 64 of the lock-side stop 61 , and the top surface 63 of the lock-side stop 61 rests against the head of the adjustment screw 62 . The lock-side stop 61 includes an adjustment screw hole 66 in registry with the adjustment screw 62 and a locking screw hole 67 in registry with the locking screw hole 37 in the frame mount 21 . The head of the adjustment screw 62 is larger than the diameter of the adjustment screw hole 66 which enables the lock-side stop 61 to rest on the head of the adjustment screw 62 .
The lock-side assembly 60 expands between a closed position depicted in FIG. 3 and an open position depicted in FIG. 4 . The distance between the top surface 63 of the lock-side stop 61 and the bottom surface 23 of the frame mount 21 depends on the depth in which the adjustment screw 62 is inserted into the door jamb. In FIG. 3 , the adjustment screw is inserted into the door jamb, such that the top surface 63 of the lock-side stop 61 is in contact with the two parallel side walls 24 of the frame mount 21 . In FIG. 4 , the adjustment screw 62 has not penetrated the door jamb as deeply as the adjustment screw depicted in FIG. 3 , thus the lock-side assembly 60 has expanded to the open position because the top surface 63 of the lock-side stop 61 rests on the head of the adjustment screw 62 . The adjustment screw hole 66 in the lock-side stop 61 provides access to the adjustment screw 62 to vary the depth of the adjustment screw 62 in the door jamb. When a user has selected the appropriate depth for the adjustment screw 62 , the lock-side stop 61 is locked in place by inserting a locking screw through the locking screw holes 67 , 37 in the lock-side stop 61 and the frame mount 21 .
The door stop 65 of the lock-side stop 61 optionally includes a weather stripping groove 72 . The lock-side stop 61 optionally includes a clearance hole 68 in registry with the mounting screws 69 for the frame mount 21 to provide quick access to the mounting screws 69 without having to remove the lock-side stop 61 . The lock-side stop 61 also optionally includes a cover groove 70 in which the adjustment holes 66 , locking holes 67 , and clearance holes 68 reside. The cover groove 70 accepts a cover in order to conceal the various screws and provide a more aesthetically pleasing look for the lock-side assembly 60 when installed. The lock-side assembly 60 optionally includes a notch 71 created by removing a section of the door stop 65 , so that the lip 34 and door stop 33 of the header stop 22 can rest on the lock-side assembly 60 .
While preferred embodiments of the invention have been disclosed and described in detail, it is to be understood that the invention is not so limited, but rather it is intended to include all embodiments which would be apparent to one skilled in the art and which come within the spirit and scope of the invention. | An expandable frame for a storm door mounted onto the header and door jamb in an entrance, a frame kit, and method of installation. The expandable frame includes an expandable header assembly, an expandable lock-side assembly and a hinge-side piece. The header assembly includes a frame mount and a header stop mounted onto the underside of the header, the hinge-side piece is mounted vertically against the door jamb on one side of the entry, and the lock-side assembly includes a lock-side stop and a frame mount mounted vertically onto the door jamb opposite the hinge section. A user can adjust the position of the header assembly and lock-side assembly to accommodate a door having smaller dimensions than the height and width of the entrance. | 4 |
FIELD OF THE INVENTION
This invention relates to a drive point device, and in particular to a device useful for underground fluid sampling, groundwater sparging, soil gas extraction, groundwater extraction or groundwater monitoring.
BACKGROUND OF THE INVENTION
Numerous devices have been proposed for groundwater sampling and monitoring, such as described in my U.S. Pat. Nos. 4,669,554 and 5,046,568. These devices are for short-term use but in some cases for geological or operational reasons it may be desirable to leave the device in the ground for reuse. In such cases, however, to reduce costs of such devices, and their use, it is desirable to be able to withdraw and reuse the drive rods after the device has been inserted into the ground without interfering with the usefulness of the device for its intended purpose. In addition, where a device is to be used for air injection, vacuum extraction or controlled sampling, it is desirable to provide a good annular seal between the device and the ground after the device is driven into the ground. It is also desirable to maintain such a seal while the drive rods are withdrawn after the drive point device has been placed in the ground.
The present invention provides a novel drive point device, means for retrofitting existing drive points, and other similar direct-push devices, such as the BAT ENVIRO PROBE sampling device, which permits reuse of the drive rods while also providing a seal between the device and the ground to facilitate air injection, vacuum extraction and groundwater sampling.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a device adapted to be inserted, e.g., driven or pushed, into the ground to create a borehole, which comprises a drive point, a fluid passage section above the drive point, sealing means, e.g. an annular sealing collar or sealing body, positionable above the intake section, either in the initial insertion of the drive point into the ground or in exposing the fluid passage section after the drive point is positioned in the ground, an annular adapter and at least one annular drive rod connected to the adapter and releasably connected to the sealing collar or body. The sealing collar or body is sized with respect to the created borehole to substantially seal it to the ground when the device is in the borehole. The fluid passage section comprises means to allow fluid to enter or leave the interior of the device below the collar and to be supplied or withdrawn to the ground surface through a conduit disposed within the device, which could also be used to accommodate sampling means. In lieu of a separate "adapter," a segment of drive rod may serve as the adapter, in which case that segment of drive rod is releasably connected directly to the sealing collar or body.
In one embodiment, an extension tube is provided adjacent the drive point which is connected to the sealing collar, either by welding or threading, an adapter (or a drive rod segment) is connected to the collar, a perforated means is disposed within the extension tube and a conduit, such as a PVC drop pipe, is disposed within the adapter and drive rod and in fluid communication with the perforated means so that fluid may pass between the perforated means and the drop pipe. In still another embodiment, a perforated pipe is provided which extends upwardly from the drive point and is connected to the sealing collar, as aforesaid. However, in this embodiment, the perforated means is a heavy-walled pipe of sufficient strength to withstand the force applied to the driving rod to drive the device into the ground. A cylindrical screen may be disposed around the perforations in the pipe to preclude dirt and other debris from clogging the pipe.
In still another embodiment, an annular seal container body is provided which extends upwardly from the drive point and which, like the sealing collar in the previous described embodiment, is sized with respect to the borehole to substantially seal the body to the ground after the device has been driven into the ground. An annular adapter is threadedly connected at its lower end to the seal container body and at its opposite end to the drive rod. In this as in all previously described embodiments, selected threaded connections are oppositely threaded so that the drive rod and adapter can be removed from the sealing collar or body by unscrewing the drive rod and releasing the adapter from the seal container body or collar and leaving the sealing collar or body in the ground with the drive point and intake section. Perforated means are disposed within the seal container body and, advantageously, may be connected to the drive point, such as by being welded or threaded thereto. A drop pipe is disposed within the drive rod which is placed in fluid communication with the fluid passage section, which in this case is by connection to the perforated means. An annular resilient sealing means may be provided for sealing around the drop pipe when the drive rod and seal container body are raised to expose the perforated means, so as to allow fluid to pass between, i.e. leave or enter, the perforated means from the borehole. The adapter described in connection with this embodiment may also be used with the other described embodiments, if desired.
To facilitate connecting the perforated pipe to the drive point, it is advantageous to provide a tapered threaded stub extending upwardly from the drive point to accommodate perforated pipes of different internal diameter. The tapered threaded stub can act to "self-thread" or "self-tap" the pipe and make the connection to the drive point. Tapered threaded stubs of different configurations, such as straight taper or stepped, threaded tapers, may be used. The latter provides still more flexibility in accommodating perforated pipes of different internal diameter.
In another embodiment the interior of the sealing collar or body may be provided with internal threads sized to self-tap the outside diameter of the drop pipe. This too may be provided in different configurations, such as a straight threaded taper or two or more stepped threaded tapers to accommodate drop pipes of different outside diameters. Additional sealing means, such as a cup seal, rod wiper or "O" rings may be provided at all threaded connections of the drop pipe to produce a substantially air-tight seal to prevent contamination to the interior of the drop pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-described and other features and advantages of the invention will be more fully understood when considered in connection with the followed detailed description and accompanying drawings, wherein:
FIG. 1 is a schematic side elevation view of one embodiment of the device provided in accordance with the invention;
FIGS. 2, 3 and 4 are schematic side views of different embodiments of the drive point as it may be threaded to facilitate self-tapping of perforated plastic
FIGS. 5 and 6 are schematic side views of different embodiments showing internally self-threading connectors for plastic drop pipes;
FIGS. 7 and 9 are schematic side elevation views of the embodiments of FIGS. 1 and 8, respectively, with the fluid passage sections exposed;
FIG. 8 is a schematic side elevation of another embodiment of the invention; and
FIG. 10 is a schematic side elevation view of an additional embodiment of the invention.
DETAILED DESCRIPTION
The drive point device and various embodiments of the device and components thereof are described in the following description in conjunction with the accompanying drawings wherein like numbers refer to like parts.
As shown in the drawings, referring to FIG. 1, the drive point device of the invention may advantageously employ an inexpensive drive point 10a, also referred to as "cone," which is at the lowermost portion of the device to facilitate driving the device into the ground, an extension tube 12a, sealing collar 14a, adapter 16a and annular drive rods 18. A perforated pipe 20, or the like, is disposed within the extension tube to facilitate fluid passage to and from the ground zone in which the device is driven. A drop pipe 22 is provided to be in fluid communicating relationship with the perforated pipe, in the embodiment shown as being threadedly connected thereto. An important aspect of the invention is that the device includes means for providing a substantial seal with the ground when the device is in a borehole. The sealing mechanism in the embodiment shown in FIG. 1 is a sealing collar 14a. The sealing collar 14a is releasably connected to the adapter 16a, such as by the threaded connection shown or by other known quick-release mechanisms. The annular drive "rod" 18 is connected to the adapter 16a and more than one drive rod segment may be sequentially connected to each other as necessary to drive the drive point to the desired depth in the ground. In lieu of adapter 16a, a drive rod segment with an oppositely threaded end may serve as an "adapter" for connection to the collar. Any suitable releasable connecting means may be employed, such as a pin and keyway or other type of connector that would permit the disconnection of the drive rod downhole. However, the presently preferred releasable connecting means is the use of reverse threads at adjacent ends of the sealing collar and adapter so that the drive rod and adapter can be released from the sealing collar by unscrewing the drive rod and thereby releasing the adapter from the sealing collar so as to isolate the collar and the fluid passage section comprising the perforated pipe located beneath the collar, which remain in the ground after the drive rods and adapter are removed following insertion and connection of the drop pipe to the perforated pipe.
As previously described, a drop pipe 22, which may be a PVC pipe or pipe made of other inexpensive material, is disposed within the drive rod 18 and is located to be in fluid-communicating relationship with the means comprising the fluid passage section of the device. If the fluid passage section comprises a perforated pipe, then the drop pipe may be connected to, or disposed adjacent the upper end of, the perforated pipe, and if the fluid passage section comprises a screen, the drop pipe can be similarly located in fluid-communicating relationship with the screen. The drop pipe 22 should be sealed in such a manner to avoid contamination to the interior of the pipe from above the fluid passage section. This may be accomplished by connecting the drop pipe to the collar as in FIG. 1, such as by threading the pipe to the collar as shown or by connecting the drop pipe to the perforated pipe in the fluid passage section.
The term "fluid passage section" as used herein is intended to refer to that portion of the device that enables passage of fluid, gas or liquid, in directions to and from, i.e. between the ground (including ground water) and the device. Thus, the device may be used to withdraw fluid, e.g. for sampling, etc., or for introducing pressurized fluid to the ground.
An important aspect of the invention is that it is possible to leave the fluid passage section within the borehole while removing the drive rod after the device has been placed in proper position within the ground. Properly sizing the internal diameter of the drive rod to be used enables a smaller-diameter, less-expensive drop pipe to be run inside the drive rod and connected, e.g. threaded, to the adapter or collar or to the perforated means directly. After the internal pipe is connected, the drive rod(s) may be disconnected and removed, leaving the drop pipe to provide a fluid-passing connection between the intake section and the ground surface. The sealing collar provides a tight annular seal for sparging or soil gas and groundwater removal.
Where desired, a grout seal can be placed inside the drive rod but outside the drop pipe as the drive rod is removed. This is another way of providing a seal between the drop pipe and the surface.
To seal the device to the ground, the sealing collar has an enlarged diameter and is sized so that a substantial seal is formed between the collar and the ground, i.e. lateral surfaces of the borehole formed by driving the device into the ground. In other words, the outside diameter of the sealing collar is not less than the outer diameter of the other components of the device.
In the embodiment illustrated, the drive point includes a centrally extending stub 11 which leaves a shoulder 13 around the perimeter of the drive point into which the extension tube 12a is fitted. Also shown in this embodiment is a stub that terminates in a tapered threaded portion 15. The tapered threaded portion provides an excellent means for connecting the perforated pipe to the drive point and is able to accommodate pipe of different internal diameter. The threads also allow a plastic pipe to "self-thread" or "self-tap" and form a sealed connection to the drive point, thereby allowing the fluid-passing contact zone with the ground to be controlled by controlling the positioning of the perforations.
To introduce fluid into or out of the fluid passage section, the drive rod(s) 18 are raised, which in turn raises the sealing adapter 16a and collar 14a and the extension tube 12a to the position shown in FIG. 7. By raising the extension tube, fluid is allowed to enter or leave the interior of the device through perforations in pipe 20. As can be seen, this permits the extraction of a fluid sample through the drop pipe or the application of a vacuum force where the device is used for vacuum extraction. If a sample is to be taken, a suitable sampling device, as known to the art, is sent down the drop pipe. Alternatively, vacuum may be applied to extract the fluid, e.g. water or volatile organics, from the borehole and the ground surrounding the borehole in the vicinity of the fluid passage section of the device. In another alternative, fluid under pressure may be injected into the pipe for sparging purposes. The portion of the device from the collar down toward the drive point may be left in the ground along with the internal drop pipe. Similarly, the drop pipe itself may be fixed in position since it is connected to the sealing collar directly.
Alternative drive point configurations to those shown in FIG. 1 are shown in FIGS. 2-6. The drive point in FIG. 2 has a straight tapered stub designed to enable a plastic perforated pipe of varied internal diameter to self-tap and be secured to the drive point, as previously described. FIG. 2 and FIG. 3 show the same configuration with the groove 6, FIG. 2, and an "O" ring 8 shown in the groove in FIG. 3, to provide a seal between an extension tube such as 12a in FIG. 1 and the drive point 10b before the extension tube is raised to expose the fluid passage section, i.e. the perforated pipe 20 in this embodiment. An oversize groove can accommodate "O" rings of various thicknesses. In lieu of the tapered threads 15 shown in FIG. 3, the stub 11 may be provided with concentric barbs to fasten the pipe 20 to the drive point.
Another variation is the drive point shown in FIG. 4, which has a stepped threaded stub, designed to accommodate a still wider range of plastic pipe internal diameters which may be connected at 17a or 17b. This figure also shows the use of shims 19 that may be used to fit oversize extension tubes to the drive point.
An alternative technique for joining the plastic drop pipe to the intake section is shown in FIGS. 5 and 6, where the annular sealing collar 14a is provided with internal threads, which may be a straight taper 25 as shown in FIG. 5 or a stepped taper 27 as shown in FIG. 6. Here too, the threads may facilitate the self-tapping of the plastic drop pipe and seals 29a and b, such as a cup seal, rod wiper or "O" ring, may be provided to seal the pipe and prevent contamination to the interior. If desired, a seal, e.g. a cup seal 31 (FIG. 5), can be provided at the top of the perforated pipe or screen to prevent fluid injected into the device from bypassing between the pipe and extension tube when the tube is raised. With the embodiments shown in FIGS. 5 and 6 the drop pipe is not connected directly to the perforated pipe, but is nonetheless in fluid-communicating relationship with the perforated pipe.
A variation of the embodiment of FIG. 1 is shown in FIG. 8. In this embodiment a similar drive point 10b is used, to which is connected a perforated pipe 20 by means of threaded tapered stub 15, and a drop pipe 22 is connected directly to the perforated pipe 20. However, an elongated annular sealing body 14b replaces the extension tube 12a and the sealing collar 14a, shown in FIG. 1, and performs the function of both. Thus, the sealing body 14b seals the device to the lateral surfaces of the borehole, just as does the collar 14a since it is also sized so that none of the other components of the device have a larger outside diameter.
In the embodiment of FIG. 8, an adapter 16b is connected to both the sealing body 14b and drive rod 18, as in FIG. 1, with opposite ends reverse-threaded. Therefore, the adapter 16b is removable with the drive rods 18 while leaving the sealing body 14b downhole with the drive point 10b and perforated tube 20.
Raising the drive rods as shown in FIG. 9 while in place causes the seal container body to be raised from the drive point, exposing the interior perforated pipe or screen so as to allow fluid to enter. A resilient seal such as a cup seal or "wiper" 30 is provided to seal to the outside surface of the drop pipe above the perforated pipe or screen when the seal container body is raised to a position where the cup seal contacts the solid drop pipe attached to the perforated pipe or screen. Once the seal container body is raised so that the cup seal is in contact with the drop pipe, the drive rod(s) may be removed for reuse, leaving the drop pipe sealed to the seal container body within the borehole. Fluid-sampling devices may be inserted or a vacuum may be applied or pressurized fluid for sparging may be introduced, as desired.
The resilient seal may be comprised of an internal gasket such as a rod wiper. However, any similar device may also be used to seal the outside diameter of the drop pipe instead of having an internal pipe threaded as shown in the previous embodiment. The drop pipe, which can be threaded directly onto the top of the screen, will slide through the seal, or alternatively the screen and drop pipe can be put into place after the power point device is driven into position in the ground but before opening the intake section.
The device of the present invention eliminates the need for long bodies to house the intake section, e.g. screen, since the screen can be disposed within the drive rods as the device is driven into position. In order to effect a substantial seal between the device and the lateral surfaces of the borehole, i.e. the surrounding ground, the sealing collar or sealing body should be the same diameter as the drive rod or larger.
FIG. 10 illustrates still another embodiment of the device and shows a drive point 10c, sealing collar 14c and adapter 16c. However, in this embodiment, a perforated heavy-walled pipe 40 replaces both the extension tube 12a and perforated pipe 20 in the embodiment shown in FIG. 1. Also, a cylindrical screen 42 is shown surrounding the pipe 40 to prevent debris from entering the pipe. The pipe is shown threadedly connected to the adapter but it may be welded or joined by any other suitable means. The collar 14c is threadedly connected, with reverse threads, to the adapter 16c so that the adapter can be removed with the drive rods after the device has been driven into place. At the opposite end, to the connection to the pipe 42, the collar is provided with internal threads, which may be as shown in FIGS. 5 and 6, to enable drop pipe 22 to connect to the collar 14c and be in fluid communication with the fluid passage section, e.g. perforated pipe 40. Drive rods may be connected to the adapter 16c, as shown.
In this configuration, after the drive rod 18 and adapter 16c are removed, the drop pipe 22 will remain attached to the collar 14c and in fluid-communicating relationship with the interior of the perforated pipe 40.
The FIG. 10 embodiment also shows how a standard drive point may be retrofitted with a collar to enjoy the benefits of the invention. The extension tube of FIG. 1 is replaced with the heavy-walled pipe 40 and is advantageously surrounded with a cylindrical screen 42 to prevent silt or other debris from clogging the perforated pipe 40, collar 14c and adapter 16c to facilitate the connection to the drive rod 18. The heavy-walled pipe is sturdy enough to enable the drive point to be driven into the ground by applying force to the driving rod connected to the sealing collar and/or adapter. For example, elements 10C, 40 and 42 would comprise a "standard drive point."
The collar is provided with threaded interior and threaded exterior sections, as previously described, and the adapter is threadedly connected to the collar and the annular drive rod is threadedly connected to the adapter. The threads connecting the adapter to the collar are opposite so that the adapter and drive rod can be released and removed from the collar by unscrewing the drive rod and releasing the adapter from the sealing collar. Alternatively, as discussed above, a segment of drive rod may be used as an adapter by oppositely threading the lower end to connect to the collar.
Although threaded connections between the heavy-walled pipe and the sealing collar are shown, it would also be possible to weld the two together if desired. In use, the drive point, heavy-walled pipe and screen remain in position in the ground after the adapter and drive rods have been removed following connection of the drop pipe to the sealing collar.
It is apparent from the foregoing that various changes and modifications may be made without departing from the invention. For example, a septum and septum-retaining means may be disposed at the top of the fluid-passage section, e.g. perforated pipe which may be penetrated by a probe sent down the drop pipe to extract a sample. Accordingly, the scope of the invention should be limited only by the appended claims, wherein | Described is a device for driving into the ground which includes a drive point, a fluid passage section, an annular seal and an annular drive rod. The annular seal is the widest member and fits snugly in a borehole formed after the device is driven into the ground to form a seal. Specially configured drive points are also described. | 4 |
BACKGROUND OF THE INVENTION
This invention relates generally to fatigue-resistant and damage-tolerant components and methods of producing such components.
Various metallic, ceramic, and composite components, such as gas turbine engine fan and compressor blades, are susceptible to cracking from fatigue and damage (e.g. from foreign object impacts). This damage reduces the life of the part, requiring repair or replacement.
It is known to protect components from crack propagation by inducing residual compressive stresses therein. Methods of imparting these stresses include shot peening, laser shock peening (LSP), pinch peening, and low plasticity burnishing (LPB). These methods are typically employed by applying a “patch” of residual compressive stresses over an area to be protected from crack propagation, for example a leading edge of a gas turbine engine compressor blade.
During a burnishing operation, the depth of the compressive residual stress layer can be controlled with process parameters. It is known to control those parameters to transition from high stress areas to low stress areas to prevent a high gradient from compressive to tensile stress fields (this technique is known as “feathering”). However, through the rest of the process, the parameters are held constant, even when processing non-uniform cross-sections (triangular cross-sections, for example). This can result in areas of tensile stresses between layers of compressive residual stress, along with areas where the compressive residual stresses are higher than the intended range.
FIG. 1 illustrates a generic metallic component 10 with a surface 12 . A burnishing element 14 is pressed against the surface under substantial pressure and translated along a selected path. In this example the burnishing element 14 is a sphere, but cylindrical rollers are also used. Typically a pressurized fluid is used to force the burnishing element 14 onto the surface 12 of the component 10 . Mechanically loaded tools are also used. Appropriate equipment, of a known type, typically CNC controlled, is provided to load the burnishing element 14 , and to move it along the desired path. The pressing force used during burnishing is such that it induces plastic strain and a region of residual compressive stresses 16 within the component 10 near a burnished area 18 . A region of residual tensile stresses 17 exists around the border of the region 16 .
FIG. 2 illustrates an exemplary gas turbine engine compressor blade 20 . This component is used merely as an example of a part to which both prior art methods and the present invention may be applied. the present invention is equally applicable to other types of components susceptible to cracking from fatigue or damage, such as compressor stator vanes, fan blades, turbine blades, shafts and rotors, stationary frames, actuator hardware and the like. Such components may be made from metal alloys, ceramics, or composite materials (e.g. carbon fiber composites). The compressor blade 20 includes an airfoil 22 , a platform 24 , and a shank 26 . In this particular example the shank 26 includes a dovetail 28 for being received in a slot of a rotating disk (not shown). The airfoil 22 has a leading edge 30 , a trailing edge 32 , a tip 34 , a root 36 , a pressure side 38 , and a suction side 40 opposite the pressure side 38 . A burnishing tool 42 carrying a burnishing element 14 is shown tracing out a selected burnishing path “P” along the surface of the airfoil 22 . In this example, the path “P” includes a plurality of linear segments 23 arranged in a series of S-turns. The path has a footprint with a width “W” determined by the width of the burnishing element 14 and the applied pressure. The linear segments 23 are separated by an step-over distance “S”. In cases where the step-over distance S is less than the width W, overlap of the segments 23 will occur. In most applications, there will be substantial overlap to achieve adequate coverage and desired stress profiles.
FIGS. 3A and 3B illustrate a prior art burnishing treatment being applied to edge 32 of the airfoil 22 . FIG. 3A shows the treatment being applied to the pressure side 38 by a single burnishing element 14 , while the airfoil is supported by a block 44 . In this case, a constant applied pressure in the normal direction “f” is selected to generate a region 46 of residual compressive stress which has depth “d” defined as a distance from the surface of the pressure side 38 , expressed as a fraction of the total thickness of the airfoil 22 at the point of measurement. The burnishing element 14 is moved from left to right. The depth d will decrease substantially as the burnishing element 14 traverses the thicker portion of the airfoil 22 distal from the trailing edge 32 . The result is that the interior boundary 48 of the region 46 is not parallel to a mid-chord plane M of the airfoil 22 . Under these circumstances, the depth d will vary significantly from a desired magnitude at opposite axial ends of the region 46 , regardless of which end is used as the basis for setting the applied pressure.
FIG. 3B illustrates the prior art burnishing treatment being applied to both the pressure side 38 and the suction side 40 of the airfoil 22 by opposed burnishing elements 14 and 14 ′. In this case, the applied pressure in the normal directions, denoted f and f′, are selected to generate regions 50 and 52 of residual compressive stress which have depths d and d′ measured from the surface of the pressure side 38 and suction side 40 , respectively, and expressed as a fraction of the total thickness of the airfoil 22 at the point of measurement. The depths d and d′ are typically chosen to generate through-thickness residual compressive stress near the trailing edge 32 . However, as shown, the depths d and d′ will decrease substantially as the burnishing elements 14 and 14 ′ traverse the thicker portion of the airfoil 22 distal from the trailing edge 32 . The result is that the interior boundaries 54 and 56 of the regions 52 and 54 are not parallel to a midplane M of the airfoil 22 . If the pressures f and f are just enough that through-thickness residual compressive stress is produced near the trailing edge 32 , this results in an internal region 58 of residual tensile stress at thicker portions of the airfoil 22 . It is possible to select the pressures f and f′ so that the regions 50 and 52 merge to produce through-thickness residual compressive stress, even at the thickest portion of the treated area. However, this would result in excessive compressive stress levels near the trailing edge 32 , because of overlap of the regions 50 and 52 . It could also damage the airfoil 22 and result in undesired deformation.
In light of the above shortcomings of the prior art, there is a need for a method of producing uniform through-thickness residual compressive stresses in components of variable thickness.
BRIEF SUMMARY OF THE INVENTION
The above mentioned need is met by the present invention, which provides a method for varying the parameters of a burnishing operation in consideration of the workpiece thickness so that a desired penetration depth of residual compressive stress is achieved regardless of local thickness.
According to one aspect, the invention provides a component having at least one exterior surface, the component including at least one region of residual compressive stress extending inwards from the surface in at least one selected area within which the thickness of the component varies, the region surrounded by an interior boundary.
According to another aspect of the invention, an airfoil for a gas turbine engine includes a root spaced apart from a tip, spaced-apart leading and trailing edges, a suction side extending from the leading edge to the trailing edge, and an opposed pressure side extending from the leading edge and the trailing edge. A thickness of the airfoil is defined between the pressure side and the suction side; and a first region of residual compressive stress extending inward from a first area of a selected one of the pressure side and the suction side. The thickness of the airfoil varies within the first area, and the first region is surrounded by a first interior boundary, A second region of residual compressive stress extends inward from a second area of a the other one of the pressure side and the suction side, the thickness of the airfoil varying within the second area, wherein the second region is surrounded by a second interior boundary. Substantially all of the first and second interior boundaries are blended together.
According to another aspect of the invention, a method of reducing crack propagation in components includes: providing a component having an exterior surface; and using a burnishing element to apply a varying pressure to the exterior surface within a selected area, within which the component has a varying thickness, so as to create a region of residual compressive stress surrounded by an interior boundary; wherein the distance from the interior boundary to the exterior surface at any given location within the selected area is independent of the thickness of the component at that location.
According to another aspect of the invention, a method of reducing crack propagation in components includes providing a component having opposed, spaced-apart first and second exterior surfaces; and using first and second burnishing elements to apply a varying pressure to the exterior surfaces within respective first and second selected areas, within which the component has a varying thickness, so as to create first and second regions of residual compressive stress surrounded by first and second interior boundaries. The distance from each of interior boundaries to the respective exterior surface at any given location within the respective selected area is independent of the thickness of the component at that location.
According to another aspect of the invention, a method of reducing crack propagation in components, includes: providing a component having opposed, spaced-apart first and second exterior surfaces; and using a first burnishing element to apply a pressure to the first exterior surface within a first selected area, within which the component has a varying thickness, while moving the first burnishing element along a first preselected path including segments separated by a step-over distance, so as to create a first region of residual compressive stress surrounded by a first interior boundary; wherein the step-over distance is selected to control an amount of overlap between adjacent segments, consequently changing the distance from the first interior boundary to the first exterior surface, such that the distance from the interior boundary to the first exterior surface at any given location within the first selected area is independent of the thickness of the component at that location.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which:
FIG. 1 is a schematic side view of a prior art burnishing process being applied to a surface of a component;
FIG. 2 is a schematic perspective view of a prior art burnishing process being applied to a gas turbine engine compressor blade;
FIG. 3A is a schematic side view of a prior art burnishing treatment being applied to a single side of the compressor blade of FIG. 2 ;
FIG. 3B is a schematic side view of a prior art burnishing treatment being applied to both sides of the compressor blade of FIG. 2 ;
FIG. 4A is a schematic side view of a burnishing treatment as described herein being applied to a single side of a compressor blade;
FIG. 4B is a schematic side view of a burnishing treatment as described herein being applied to both sides of a compressor blade; and
FIG. 5 is a side view of a burnishing treatment as described herein being applied to a component of variable thickness.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 4A and 4B illustrate an exemplary burnishing treatment in accordance with an aspect of the invention being applied to the trailing edge region of an airfoil 122 , which before treatment is identical to the airfoil 22 described above. FIG. 4A shows the treatment being applied to the pressure side 138 within a selected area by a burnishing element 114 , while the airfoil 122 is supported by a block 144 . The treatment described herein may be applied to any portion of the airfoil 122 . In this case, the applied pressure in a direction normal to the surface, indicated at F, is selected to generate a region 146 of residual compressive stress which has a depth D (this could also be described as penetration) measured from the surface of the suction side 138 , and expressed as expressed as a fraction of the total thickness of the airfoil 122 at the point of measurement. To achieve a more uniform depth D, the burnishing parameters are changed as the burnishing element 114 moves to areas of different thicknesses. Specifically, as the burnishing element 114 is moved from a position near the trailing edge 132 to a thicker portion of the airfoil 122 distal from the trailing edge 132 , the pressure F in the normal direction is increased. The pressure is generally proportional to the thickness. Using this varying pressure, it is possible to generate a region 146 which has an interior boundary 148 with a selected profile. The interior boundary 148 may be made parallel to an arbitrary preselected interior plane. In the illustrated example, a substantial portion of the interior boundary 148 is substantially parallel to, and coincident with, a midplane M of the airfoil 122 .
The depth D may also be manipulated to control the interior boundary 148 in whole or in part by controlling the amount of overlap between burnished segments as the burnishing element 114 is moved through a selected path. For example, if the step-over distance (denoted “S” in FIG. 2 ) is greater than the burnished segment width “W”, there will be no overlap. As the step-over distance is decreased to less than the width “W”, the overlap increases. The greater the overlap, the greater the depth D will be. This is true even when the applied pressure is held constant, although the effect on depth D of overlap alone is thought to be less than that of the burnishing pressure,
FIG. 4B illustrates an exemplary burnishing treatment in accordance with another aspect of the invention being applied to both the pressure side 138 and the suction side 140 of the airfoil 122 within selected areas thereof by opposed burnishing elements 114 and 114 ′. In this case, the applied pressures in the normal directions, indicated at F and F′ are selected to generate regions 150 and 152 of residual compressive stress which have depths D and D′ measured from the surface of the pressure side 138 and suction side 140 , respectively, and expressed as a fraction of the of the total thickness of the airfoil 122 at the point of measurement. This depths D and D′ are chosen so that substantially all of their interior boundaries 154 and 156 are blended together at a midplane M of the airfoil 122 . Substantially all of, or portions of, the interior boundaries 154 and 156 may be coincident with each other. This results in the generation of through-thickness residual compressive stress in the selected areas without exceeding desired compressive stress levels. As noted above, the interior boundaries 154 and 156 may have arbitrary preselected profiles and may be made parallel to arbitrary, preselected interior planes. The area of residual tensile stress 58 described above with respect to the prior art method is eliminated.
The depths D and D′ may also be manipulated to control the interior boundaries 154 and 156 in whole or in part by controlling the amount of overlap between burnished segments as the burnishing elements 114 and 114 ′ are moved through selected paths, as described above with respect to the single burnishing element 114 .
FIG. 5 illustrates the another exemplary burnishing treatment in accordance with an aspect of the invention being applied to a surface 238 of a component 222 within a selected area by a burnishing element 214 . In this case, the surface 138 includes at least one feature 139 (such as a ridge or groove) which extends significantly above or below the remainder thereof. The applied pressure F in the normal direction is varied as described above to generate a region 250 of residual compressive stress which has a varying depth D″ measured from the surface 238 and expressed as a fraction of the total thickness of the component 222 at the point of measurement. Using this varying pressure, it is possible to give the interior boundary 254 a selected profile. The interior boundary 254 may be made parallel to an arbitrary preselected interior plane. In this case, the depth D″ is varied such that substantially all of the interior boundary of 254 of the region 250 is substantially parallel to the surface 238 .
The pressure variation described above may be achieved in various ways. For example, the pressure could be manually varied by operator control as the burnishing element traverses different portions of the workpiece. However, as the motion of the burnishing element is typically CNC-controlled, it is possible to analyze the dimensions of the workpiece and based on those dimensions, generate and store a data “map” relating desired pressure to identifiable coordinates points on the workpiece. The pressure on the burnishing element would then be automatically varied by the burnishing equipment based on reference to the map as the burnishing equipment moves the burnishing tool through a selected path having segments separated by a step-over distance as described above. In addition, the step-over may be controlled either to manipulate the overlap between segments when using a constant pressure, as described above, or to hold a selected amount of overlap constant throughout the process, since the width of the burnished segment varies with varying pressure. For example, if the burnishing pressure is increased, causing an increase in the width of the burnishing line, the control would correlate the increased pressure to the resulting increased with and the step-over distance for the next segment would be decreased so that the overlap is not undesirably increased.
The foregoing has described fatigue- and damage-resistant components and methods for making such components. While specific embodiments of the present invention have been described, it will be apparent to those skilled in the art that various modifications thereto can be made without departing from the spirit and scope of the invention. Accordingly, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation, the invention being defined by the claims. | A method of reducing crack propagation includes: providing a metallic component having an exterior surface, and using a burnishing element to apply a varying to the exterior surface within a selected area, within which the component has a varying thickness, so as to create a region of residual compressive stress of surrounded by an interior boundary. The distance from the interior boundary to the exterior surface at any location within the selected area is independent of the thickness of the component at that location, and may be controlled by changing the pressure and/or an amount of overlap between burnished segments. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a liquid raw material supply unit for a vaporizer for supplying a liquid raw material to the vaporizer.
[0003] 2. Description of Related Art
[0004] In recent years, a high-integration design has been demanded for semiconductor memory devices and embedded memory LSIs using capacitors such as DRAM (Dynamic Random Access Memory) and FeRAM (Ferroelectric Random Access Memory). In response to such demands, high dielectric constant materials have to be used for manufacture of semiconductors. The high-dielectric materials are often used in liquid state. In many cases, accordingly, a liquid raw material is supplied to a vaporizer in which the liquid raw material is vaporized, and this vaporized gas is supplied to a reactor. This process therefore needs a liquid raw material supply line for supplying the liquid raw materials to the vaporizer.
[0005] If the liquid raw material remains in the liquid raw material line and the vaporizer, it may result in reaction products which will be deposited in the line and the vaporizer. Such deposits are likely to cause various problems; e.g., they become a particle generation source, leading to a lower yield ratio, they clog control valves and line pipes, or they clog nozzles of the vaporizer. To avoid those problems, the liquid raw material supply line is usually subjected to a cleaning process after supply of the liquid raw material to the vaporizer. In the cleaning process, the liquid raw material remaining in the line pipes and the vaporizer is cleaned or washed with a cleaning solution (by liquid-liquid replacement) and then the cleaning solution is removed from the line pipes and the vaporizer by a purge gas (by liquid-gas replacement).
[0006] An example of the above liquid raw material supply line is arranged as shown in FIG. 6 that liquid raw material lines 101 and 102 each comprising a valve and pipes for feeding a liquid raw material and a cleaning solution line 103 comprising a valve and pipes for feeding a cleaning solution are connected to a main line 105 with one end connected to a vaporizer and the other end connected to a purge gas line 104 . In this liquid raw material line, a liquid raw material is fed from the liquid raw material line 101 or 102 to the main line 105 , and the liquid raw material fed into the main line 105 is then supplied to the vaporizer.
[0007] For cleaning, here, the cleaning solution is fed from the cleaning solution line 103 to the main line 105 , thereby cleaning the line and the vaporizer through which the liquid raw material has passed with the cleaning solution. After cleaning using the cleaning solution, a purge gas is introduced into the purge gas line 104 to thereby remove the remaining cleaning solution from the liquid raw material supply line.
[0008] Another example of the liquid raw material supply line is shown in FIG. 7 , which is arranged such that monoblock valves X 1 to X 4 each comprising a plurality of valves are connected to each other through pipes. In this liquid raw material supply unit, a pressurizing gas (e.g., He gas or another inert gas) is fed into a valve V 2 of the monoblock valve X 1 and then enters a liquid raw material tank 121 through a valve V 1 of the monoblock valve X 1 and a valve V 4 of the monoblock valve X 2 to pressurize the liquid raw material to be supplied to the vaporizer through the valve V 1 of the monoblock valve X 2 , and the monoblock valves X 3 and X 4 in order.
[0009] For cleaning, here, when a washing solution is fed into the valve V 1 of the monoblock valve X 1 , the washing solution flows in the monoblock valve X 3 via a valve V 3 of the monoblock valve X 2 . The washing solution then flows in a valve V 2 of the monoblock valve X 3 and a valve V 2 of the monoblock valve X 4 sequentially. By this process, the passages through which the liquid raw material has passed are cleaned. After cleaning using the washing solution, an inert gas such as an Ar gas is introduced as a purge gas into a valve V 3 of the monoblock X 1 to remove the remaining washing solution from the passages.
[0010] However, both the aforementioned liquid raw material supply lines are fundamentally constructed of a plurality of valves and a plurality of pipes. This construction disadvantageously needs a large mounting space, which could impede miniaturization and high integration.
[0011] In the former liquid raw material line, when the cleaning solution is fed into the main line 105 for cleaning, a liquid remaining or staying zone (a dead space) tends to occur in the liquid raw material supply line 101 or 102 . When the purge gas is fed into the main line 105 , on the other hand, a liquid remaining or staying zone (a dead space) is likely to occur in the liquid raw material supply lines 101 and 102 and the cleaning solution supply line 103 respectively. Thus, a replacement rate (or replacement capability) of the residual or remaining liquid (a liquid-liquid replacement rate and a liquid-gas replacement rate) is poor, which needs much time for replacement of the residual liquid, resulting in a longer cleaning time. This also leads to a prolonged cycle time of a semiconductor manufacturing device and hence a lower manufacturing efficiency. Further, the liquid-gas replacement rate is extremely poor with the result that the cleaning solution remaining after cleaning could not be replaced completely by the purge gas.
[0012] In the latter liquid raw material supply line, on the other hand, the time required for cleaning could be shortened (the replacement rate of the residual liquid could be enhanced). However, the monoblock valves X 1 to X 4 used in the line have very complicated flow passages respectively.
BRIEF SUMMARY OF THE INVENTION
[0013] The present invention has been made in view of the above circumstances and has an object to provide a liquid raw material supply unit in a miniaturized and integrated design with simple passage configurations, capable of reducing liquid remaining or staying zones, thereby enhancing a replacement rate of residual liquid.
[0014] Additional objects and advantages of the invention will be set forth in part 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 attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
[0015] To achieve the above object, the present invention provides a liquid raw material supply unit for a vaporizer, adapted to supply a liquid raw material to the vaporizer that vaporizes the liquid raw material, the unit comprising: a manifold internally formed with a flow passage; and a plurality of fluid control valves mounted on the manifold, wherein the plurality of fluid control valves includes: a liquid raw material control valve for controlling supply of the liquid raw material to the flow passage; a cleaning solution control valve for controlling supply of a cleaning solution to the flow passage; a purge gas control valve for controlling supply of a purge gas to the flow passage; and a first introducing control valve connectable to the vaporizer for controlling supply of a fluid from the flow passage to the vaporizer, the purge gas control valve, the cleaning solution control valve, the liquid raw material control valve, and the first introducing control valve being mounted on the manifold in this order from an upstream side of the manifold, wherein the flow passage is connected to valve ports of the plurality of control valves respectively, the valve ports communicating with valve openings of the respective control valves, and the flow passage is configured to allow the purge gas supplied from the purge gas control valve to directly flow in the valve ports of the cleaning solution control valve and the liquid raw material control valve placed downstream from the purge gas control valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate an embodiment of the invention and, together with the description, serve to explain the objects, advantages and principles of the invention.
[0017] In the drawings,
[0018] FIG. 1 is a partially sectional view showing a schematic configuration of a liquid raw material supply unit in a preferred embodiment;
[0019] FIG. 2 is a graph showing test results of a liquid-liquid (salt water-pure water) replacement rate in the case where salt water is supplied from a first liquid raw material supply valve (line);
[0020] FIG. 3 is a graph showing test results of a liquid-liquid (salt water-pure water) replacement rate in the case where salt water is supplied from a second liquid raw material supply valve (line);
[0021] FIG. 4 is a sectional view showing a schematic configuration of a liquid raw material supply unit in a comparative example;
[0022] FIG. 5 is a partially sectional view showing a schematic configuration of a liquid raw material supply unit in another example;
[0023] FIG. 6 is a schematic diagram of a structural outline of a liquid raw material supply line in a prior art; and
[0024] FIG. 7 is a schematic diagram of a structural outline of a liquid raw material supply line in another prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] A detailed description of a preferred embodiment of a liquid raw material supply unit for a vaporizer according to the present invention will now be given referring to the accompanying drawings. The configuration of the liquid raw material supply unit of the present embodiment will be explained referring to FIG. 1 . FIG. 1 is a partially sectional view showing a schematic configuration of the liquid raw material supply unit of the present embodiment.
[0026] The liquid raw material supply unit 10 includes a purge gas supply valve 30 , a cleaning solution supply valve 40 , a first liquid raw material supply valve 50 , a second liquid raw material supply valve 60 , and an introducing valve 70 connectable to a drain (hereinafter, referred to as a “drain introducing valve”, which corresponds to a second introducing valve of the present invention), which are fixedly mounted in line on the upper surface of a manifold 20 internally formed with flow passages, as shown in FIG. 1 . Further, an introducing valve 80 connectable a vaporizer (hereinafter, referred to as a “vaporizer introducing valve”, which corresponds to a first introducing valve of the present invention) is attached to the left side of the manifold 20 . Specifically, the purge gas supply valve 30 , the cleaning solution supply valve 40 , the first liquid raw material supply valve 50 , the second liquid raw material supply valve 60 , the drain introducing valve 70 , and the vaporizer introducing valve 80 are arranged in this order from the upstream side of the manifold 20 . Through a flow passage 21 formed in the manifold 20 , the purge gas supply valve 30 , the cleaning solution supply valve 40 , the first liquid raw material supply valve 50 , the second liquid raw material supply valve 60 , the drain introducing valve 70 , and the vaporizer introducing valve 80 are connected to one another. The flow passage 21 includes V-shaped passages 23 , 24 , 25 , and 26 , and a communication passage 27 . Through a flow passage 22 of the manifold 20 , the vaporizer introducing valve 80 is connected to a vaporizer.
[0027] The liquid raw material supply unit 10 is constructed to perform supply of a first liquid raw material and a second liquid raw material to the vaporizer, cleaning of the unit 10 and the vaporizer with a cleaning solution after the supplying of the first and second liquid raw materials, and removal of residual cleaning solution or others by a purge gas after the cleaning. The liquid raw material supply unit 10 comprising the valves 30 , 40 , 50 , 60 , 70 , and 80 that are mounted on the manifold 20 can achieve miniaturization and high integration. Accordingly, the liquid raw material supply unit 10 can be installed close to the vaporizer.
[0028] The purge gas supply valve 30 is configured to control supply of a purge gas (a nitrogen gas in the present embodiment) to the flow passage 21 of the manifold 20 . In the purge gas supply valve 30 , a valve chamber 31 is connected to a purge gas supply source through a valve chamber port not shown and also connected to the flow passage 21 of the manifold 20 through a valve opening 32 and a valve port 33 opening on a mounting surface (a lower surface).
[0029] The cleaning solution supply valve 40 is configured to control supply of the cleaning solution (THF in the present embodiment) to the flow passage 21 of the manifold 20 . In the cleaning solution supply valve 40 , a valve chamber 41 is connected to a cleaning solution supply source through a valve chamber port not shown and also connected to the flow passage 21 of the manifold 20 through a valve opening 42 and a valve port 43 opening on a mounting surface (a lower surface).
[0030] The first liquid raw material supply valve 50 is configured to control supply of the first liquid raw material (strontium in the present embodiment) to the flow passage 21 of the manifold 20 . In the first liquid raw material supply valve 50 , a valve chamber 51 is connected to a first liquid raw material supply source through a valve chamber port not shown and also connected to the flow passage 21 of the manifold 20 through a valve opening 52 and a valve port 53 opening on a mounting surface (a lower surface).
[0031] The second liquid raw material supply valve 60 is configured to control supply of the second liquid raw material (titanium in the present embodiment) to the flow passage 21 of the manifold 20 . In the second liquid raw material supply valve 60 , a valve chamber 61 is connected to a second liquid raw material supply source through a valve chamber port not shown and also connected to the flow passage 21 of the manifold 20 through a valve opening 62 and a valve port 63 opening on a mounting surface (a lower surface).
[0032] The drain introducing valve 70 is configured to control introduction of a fluid flowing through the flow passage 21 of the manifold 20 into a drain for discharging the fluid from the liquid raw material supply unit 10 . In the drain introducing valve 70 , a valve chamber 71 is connected to the drain through a valve chamber port not shown and also connected to the flow passage 21 of the manifold 20 through a valve opening 72 and a valve port 73 opening on a mounting surface (a lower surface).
[0033] The vaporizer introducing valve 80 is configured to control supply of a fluid flowing through the flow passage 21 of the manifold 20 to the vaporizer. In the vaporizer introducing valve 80 , a valve port 83 opening on a mounting surface (a right surface) and communicating with a valve opening 82 is connected to the flow passage 21 of the manifold 20 , and a valve chamber port 84 communicating with a valve chamber 81 is connected the flow passage 22 .
[0034] Here, the purge gas supply valve 30 , the cleaning solution supply valve 40 , the first liquid raw material supply valve 50 , the second liquid raw material supply valve 60 , and the drain introducing valve 70 are connected to one another through the flow passage 21 of the manifold 20 . To be more specific, adjacent valves, that is, the purge gas supply valve 30 and the cleaning solution supply valve 40 , the cleaning solution supply valve 40 and the first liquid raw material supply valve 50 , the first liquid raw material supply valve 50 and the second liquid raw material supply valve 60 , and the second liquid raw material supply valve 60 and the drain introducing valve 70 , are connected through the corresponding V-shaped passages 23 , 24 , 25 , and 26 respectively.
[0035] More specifically, inlets 23 a to 26 a and outlets 23 b to 26 b of the V-shaped passages 23 to 26 are formed opening on the upper surface of the manifold 20 in such a manner as to communicate with the valve ports 33 , 43 , 53 , 63 , and 73 of the valves 30 , 40 , 50 , 60 , and 70 respectively. In other words, the inlet 23 a of the V-shaped passage 23 is connected to the valve port 33 of the purge gas supply valve 30 while the outlet 23 b is connected to the valve port 43 of the cleaning solution supply valve 40 . The inlet 24 a of the V-shaped passage 24 is connected to the valve port 43 of the cleaning solution supply valve 40 while the outlet 24 b is connected to the valve port 53 of the first liquid raw material supply valve 50 . Further, the inlet 25 a of the V-shaped passage 25 is connected to valve port 53 of the first liquid raw material supply valve 50 while the outlet 25 b is connected to the valve port 63 of the second liquid raw material supply valve 60 . The inlet 26 a of the V-shaped passage 26 is connected to the valve port 63 of the second liquid raw material supply valve 60 while the outlet 26 b is connected to the valve port 73 of the drain introducing valve 70 .
[0036] As above, the outlet 23 b of the V-shaped passage 23 and the inlet 24 a of the V-shaped passage 24 are formed to open at the same position to be connected to the valve port 43 of the cleaning solution supply valve 40 . In other words, the V-shaped passages 23 and 24 are connected to each other at the outlet 23 b (or the inlet 24 a ), i.e., at a joint portion with respect to the valve port 43 . Further, the outlet 24 b of the V-shaped passage 24 and the inlet 25 a of the V-shaped passage 25 are formed to open at the same position to be connected to the valve port 53 of the first liquid raw material supply valve 50 . In other words, the V-shaped passages 24 and 25 are connected to each other at the outlet 24 b (or the inlet 25 a ), i.e., at a joint portion with respect to the valve port 53 . The outlet 25 b of the V-shaped passage 25 and the inlet 26 a of the V-shaped passage 26 are formed to open at the same position to be connected to the valve port 63 of the second liquid raw material supply valve 60 . In other words, the V-shaped passages 25 and 26 are connected to each other at the outlet 25 b (or the inlet 26 a ), i.e., at a joint portion with respect to the valve port 63 .
[0037] The valve port 73 of the drain introducing valve 70 and the valve port 83 of the vaporizer introducing valve 80 are connected through the communication passage 27 . With the above configuration, a fluid to be supplied from each of the first liquid raw material supply valve 50 , the second liquid raw material supply valve 60 , the cleaning solution supply valve 40 , and the purge gas supply valve 30 can be supplied to the vaporizer or discharged to the drain by control of the drain introducing valve 70 and the vaporizer introducing valve 80 .
[0038] Operations of the aforementioned liquid raw material supply unit 10 will be explained below. When the first liquid raw material is to be supplied to the vaporizer, the first liquid raw material supply valve 50 and the vaporizer introducing valve 80 are opened while other valves 30 , 40 , 60 , and 70 are closed. Thus, the first liquid raw material fed from the first liquid raw material supply valve 50 is allowed to pass through the flow passage 21 , i.e., the V-shaped passages 25 and 26 and the communication passage 27 and flow in the vaporizer introducing valve 80 . The vaporizer introducing valve 80 placed in an open state at this time allows the first liquid raw material flowing in the valve 80 to be supplied to the vaporizer through the flow passage 22 .
[0039] When the second liquid raw material is to be supplied to the vaporizer, the second liquid raw material supply valve 60 and the vaporizer introducing valve 80 are opened while other valves 30 , 40 , 50 , and 70 are closed. Thus, the second liquid raw material fed from the second liquid raw material supply valve 60 is allowed to pass through the flow passage 21 , i.e., the V-shaped passage 26 and the communication passage 27 and flow in the vaporizer introducing valve 80 . The vaporizer introducing valve 80 placed in the open state at this time allows the second liquid raw material flowing in the valve 80 to be supplied to the vaporizer through the flow passage 22 .
[0040] For cleaning, the cleaning solution supply valve 40 and the vaporizer introducing valve 80 are opened while the other valves 30 , 50 , 60 , and 70 are closed. Thus, the cleaning solution fed from the cleaning solution supply valve 40 is allowed to pass through the V-shaped passages 24 , 25 , 26 and the communication passage 27 and flow in the vaporizer introducing valve 80 . The vaporizer introducing valve 80 placed in the open state at this time allows the cleaning solution flowing in the valve 80 to be supplied to the vaporizer through the flow passage 22 . In this way, the cleaning solution is supplied to the passages, the valves, and the vaporizer through which the first or second liquid raw material has passed, thereby cleaning the liquid raw material supply unit 10 and the vaporizer.
[0041] When the cleaning solution is to be supplied, the valve ports 53 , 63 , and 73 may become liquid remaining zones (dead spaces), but respective volumes are extremely small as compared with a conventional case. The cleaning solution fed from the cleaning solution supply valve 40 to the V-shaped passage 24 flows in the valve port 53 of the first liquid raw material supply valve 50 and then in the V-shaped passage 25 . The cleaning solution flowing in the V-shaped passage 25 flows in the valve port 63 of the second liquid raw material supply valve 60 and then in the V-shaped passage 26 . The cleaning solution flowing in the V-shaped passage 26 flows in the valve port 73 of the drain introducing valve 70 and then in the communication passage 27 . In the above way, the cleaning solution is directly allowed to flow in the valve ports 53 , 63 , and 73 which may become liquid remaining zones. Accordingly, the cleaning solution collides with the residual liquid staying in the valve ports 53 , 63 , and 73 sequentially to gradually push out the residual liquid from the valve ports 53 , 63 , and 73 or dissolve the residual liquid. This makes it possible to efficiently replace the residual liquid by the cleaning solution. Thus, the liquid-liquid replacement rate can be enhanced. Consequently, the first or second liquid raw material remaining in the flow passages of the liquid raw material supply unit 10 can completely be replaced by the cleaning solution in a shorter time than the conventional case.
[0042] Test results of replacement rates of the liquid raw material supply unit 10 of the present embodiment and that of the conventional liquid raw material supply line shown in FIG. 6 are shown in FIGS. 2 and 3 . FIG. 2 is a graph showing the test result of a liquid-liquid (salt water-pure water) replacement rate in the case where salt water is supplied from the first liquid raw material supply valve (line). FIG. 3 is a graph showing the test result of a liquid-liquid (salt water-pure water) replacement rate in the case where salt water is supplied from the second liquid raw material supply valve (line).
[0043] In the tests, salt water (0.5%) was filled in the flow passage instead of the liquid raw material and then pure water was supplied at a rate of 2 mL/min. Then, water discharged from the supply unit 10 and the conventional supply line through respective supply ports connectable with the vaporizers, was stored by 10 mL, and electric conductivity of the stored water was measured. Based on the previously measured electric conductivity of each of pure water and salt water, the salinity was calculated from the measured electric conductivity. In the tests, the salinity was compared between the both cases until the salt water was diluted to the salinity of 1.0 ppm or below.
[0044] In a comparison between the liquid raw material supply unit 10 and the conventional liquid raw material supply line of FIG. 6 in regard to a replacement time needed for replacement until the salinity was reduced to 1.0 ppm, as clearly found in FIGS. 2 and 3 , the liquid raw material supply unit 10 of the present embodiment (a solid line in the graph) shows a superior replacement rate to the conventional liquid raw material supply line (a dotted line in the graph). Specifically, in the case where the salt water was supplied from the first liquid raw material supply line (valve), the replacement time needed until the salinity was reduced to 1.0 ppm was about 90 min. in the liquid raw material supply unit 10 , whereas it was as much as about 220 min. in the conventional liquid raw material supply line, as shown in FIG. 2 . In the case where the salt water was supplied from the second liquid raw material supply line (valve), the replacement time needed until the salinity was reduced to 1.0 pm was about 70 min. in the liquid raw material supply unit 10 , whereas it was as much as about 170 min. in the conventional liquid raw material supply line.
[0045] The above results reveal that the liquid raw material supply unit 10 of the present embodiment can largely shorten a cleaning time needed for cleaning the liquid raw material supply unit 10 , resulting in a shortened cycle time of a semiconductor manufacturing device, thereby improving production capacity. A consumption amount of the cleaning solution can also be reduced for cutting on costs.
[0046] After completion of the cleaning using the cleaning solution as above, the purge gas supply valve 30 and the drain introducing valve 70 are opened and other valves 40 , 50 , 60 , and 80 are closed. Thus, the supply of the cleaning solution from the cleaning solution supply valve 40 is stopped while supply of a purge gas from the purge gas supply valve 30 is started. The purge gas supplied from the purge gas supply valve 30 is discharged from the liquid raw material supply unit 10 via the drain introducing valve 70 . Such supply of the purge gas is intended to completely remove the residual liquid from the liquid raw material supply unit 10 to prevent possible corrosion or other disadvantages. In some instances, the drain introducing valve 70 is closed and the vaporizer introducing valve 80 is opened to supply the purge gas to the vaporizer.
[0047] When the purge gas is to be supplied, similarly, the valve ports 43 , 53 , and 63 may become liquid remaining zones (dead spaces), but respective volumes are extremely small as compared with the conventional case. The purge gas supplied from the purge gas supply valve 30 into the V-shaped passage 23 flows in the valve port 43 of the cleaning solution supply valve 40 and then in the V-shaped passage 24 . The purge gas introduced into the V-shaped passage 24 flows in the valve port 53 of the first liquid raw material supply valve 50 and then in the V-shaped passage 25 . The purge gas flowing in the V-shaped passage 25 then flows in the valve port 63 of the second liquid raw material supply valve 60 and then in the V-shaped passage 26 . The purge gas flowing in the V-shaped passage 26 then flows in the valve port 73 of the drain introducing valve 70 , passing through the drain introducing valve 70 , and then is discharged outside.
[0048] In the above way, the purge gas is allowed to directly flow in the valve ports 43 , 53 , and 63 which may become liquid remaining zones. Accordingly, the purge gas collides with the residual liquid staying in the valve ports 43 , 53 , and 63 sequentially to gradually push out the residual liquid from the valve ports 43 , 53 , and 63 . Even where the residual liquid has large surface tension, it can be fully replaced by the purge gas. The liquid-gas replacement rate can therefore be enhanced. This makes it possible to completely remove the residual cleaning solution from the liquid raw material supply unit 10 .
[0049] Here, the liquid raw material supply unit 10 of the present embodiment provided with the manifold 20 made of acrylic was checked by a residual liquid condition in each of the valve ports 43 , 53 , 63 , and 73 . As an object for comparison with the liquid raw material supply unit 10 , a liquid raw material supply unit using a manifold 20 a provided with a flow passage configuration as shown in FIG. 4 was similarly checked by the residual liquid condition in each of valve ports 43 , 53 , 63 , and 73 . It should be noted that the manifold 20 a is formed with a main flow passage 21 a extending straight in a longitudinal direction of the manifold 20 a , in place of the flow passage 21 of the manifold 20 , and sub-passages 35 , 45 , 55 , 65 , and 75 connecting the main flow passage 21 a to the valve ports 33 , 43 , 53 , 63 , and 73 of the corresponding valves 30 , 40 , 50 , 60 , and 70 .
[0050] A comparison of the replacement capability (rate) using the purge gas between the liquid raw material supply unit 10 and the liquid raw material supply unit shown in FIG. 4 obviously indicates that the liquid raw material supply unit 10 had a superior replacement capability to the liquid raw material supply unit as shown in FIG. 4 . It was specifically found in the liquid raw material supply unit 10 that when the purge gas was supplied to the flow passage 21 of the manifold 20 , the liquid was completely replaced by the purge gas without remaining in the valve ports 43 , 53 , 63 , and 73 which may become dead spaces. It was conversely found in the liquid raw material supply unit shown in FIG. 4 that when the purge gas was supplied to the flow passage 21 a of the manifold 20 a , the liquid remained in the valve ports 43 , 53 , 63 , and 73 which might become dead spaces and the sub-passages 35 , 45 , 55 , 65 , and 75 . Thus, the liquid raw material could not be completely replaced by the purge gas.
[0051] In the liquid raw material supply unit 10 of the present embodiment as described above, the purge gas supply valve 30 , the cleaning solution supply valve 40 , the first liquid raw material supply valve 50 , the second liquid raw material supply valve 60 , and the drain introducing valve 70 are integrally mounted on the upper surface of the manifold 20 , in line in that order from the upstream side of the manifold 20 , and the vaporizer introducing valve 80 is further attached to the left side of the manifold 20 . Thus, the miniaturization and high integration can be achieved. The valve ports 33 , 43 , 53 , 63 , and 73 of the adjacent valves among the purge gas supply valve 30 , the cleaning solution supply valve 40 , the first liquid raw material supply valve 50 , the second liquid raw material supply valve 60 , and the drain introducing valve 70 are connected by the corresponding V-shaped passages 23 , 24 , 25 , and 26 . Consequently, the liquid remaining zones may be reduced to only the valve ports 43 , 53 , 63 , and 73 at most. In case liquid remains in those valve ports 43 , 53 , 63 , and 73 , it can be gradually pushed out sequentially by the replacement fluid (a cleaning solution or a purge gas) supplied from upstream to collide with the residual liquid. This makes it possible to enhance the replacement rate of the residual liquid by the cleaning solution or purge gas.
[0052] The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For instance, the aforementioned embodiment exemplified the liquid raw material supply unit 10 with the first liquid raw material supply valve 50 and the second liquid raw material supply valve 60 both being mounted on the manifold 20 for supplying two kinds of liquid raw materials. As an alternative, a unit may be arranged to supply a single kind of a liquid raw material shown in FIG. 5 , in which the first liquid raw material supply valve 50 is mounted on the manifold 20 , and a passage block 66 is mounted instead of the second liquid raw material supply valve 60 on the manifold 20 .
[0053] While the presently preferred embodiment of the present invention has been shown and described, it is to be understood that this disclosure is for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims. | A liquid raw material supply unit for a vaporizer is adapted to supply a liquid raw material to the vaporizer that vaporizes the liquid raw material. The unit comprises: a manifold internally formed with a flow passage; and a plurality of fluid control valves mounted on the manifold, wherein the plurality of fluid control valves includes: a liquid raw material control valve for controlling supply of the liquid raw material to the flow passage; a cleaning solution control valve for controlling supply of a cleaning solution to the flow passage; a purge gas control valve for controlling supply of a purge gas to the flow passage; and a first introducing control valve connectable to the vaporizer for controlling supply of a fluid from the flow passage to the vaporizer, the purge gas control valve, the cleaning solution control valve, the liquid raw material control valve, and the first introducing control valve being mounted on the manifold in this order from an upstream side of the manifold, wherein the flow passage is connected to valve ports of the plurality of control valves respectively, the valve ports communicating with valve openings of the respective control valves, and the flow passage is configured to allow the purge gas supplied from the purge gas control valve to directly flow in the valve ports of the cleaning solution control valve and the liquid raw material control valve placed downstream from the purge gas control valve. | 5 |
RELATION TO OTHER APPLICATIONS
This application is a continuation-in-part of copending U.S. Patent application Ser. No. 900,763, filed on Apr. 27, 1978.
BACKGROUND OF THE INVENTION
Hollywood bed frames are commonly made with angle iron frame members which may be folded and/or disassembled for shipping or moving and which are adjustably assemblable to accommodate different sizes of mattresses. Such frames may be provided with center support rail members stretching between the cross rails for better support of King-size mattresses. It is desirable for assembly, disassembly, and adjustment purposes that the frame members be readily but firmly attached to one another, but without the use of loose nuts, bolts, clamps, clamp screws, or other elements, and without the use of tools.
Prior efforts to provide interlocking joints for such bed frames are best exemplified in the U.S. Pat. Nos. 3,775,783 3,736,602; and 3,824,638.
U.S. Pat. No. 3,755,783 discloses assembly joints for bed frame members having pairs of L-shaped slots opening to the edges of the members for engagement with pairs of projections on mating members, and these joints are assembled and disassembled by simple rectilinear motions of the mating joint members laterally and longitudinally relative to one another. U.S. Pat. No. 3,737,602 discloses assembly joints for bedframe members having pairs of slots disposed in mutual angular relation to one another for engagement with pairs of projections on mating members, and the joints are assembled and disassembled by a combination of a relative rectilinear motion between joint elements generally parallel to one of the slots to engage one mating projection therewith, followed by a relative rotary motion between elements to engage the other slot and projection. U.S. Pat. No. 3,824,638 discloses assembly joints for bed frame members having L-shaped and straight slots adjacent one another, similar to those of the present invention, for assembly by rectilinear relative motions of the joint members parallel to the two legs of the L-slot followed by relative rotary motion between the members, to engage a projection in each of the slots.
Various combinations of slots and projections have been provided in bed frame members for interlocking assembly, by the above-mentioned patents and others not so relevant, but none have provided the yieldable, snap-action retaining features of the present invention which ensure that any disassembly of the members will be purposeful and not accidental.
SUMMARY OF THE INVENTION
Briefly described, the present invention provides an interlocking joint for snap-together assembly of first and second members of a metal bed frame and the like for assembly by complex motions which cannot be undone by simple rectilinear motions of one member relative to the other. The joint includes a first frame member having a first projection thereon having a body adjacent the member, and a second frame member with a first projection receiving slot formed therein. This first slot has an entry portion for entry of the first projection into the first slot, a communicating portion extending from the entry portion, and a projection retaining portion spaced away from the entry portion. The projection retaining portion is larger than the communicating portion, and is connected to the entry portion by the communicating portion. A resilient retaining means is associated with the first projection for engaging the periphery of the retaining portion for releasably retaining the projection in the enlarged retaining portion of the first slot.
Preferably, the resilient retaining means is disposed for resiliently compressible movement into the enlarged retaining portion for releasably preventing passage of the projection therefrom into the communicating portion, and for initial movement to permit entry of the projection into the first slot and subsequent removal from the retaining portion. Preferably the retaining means includes a contacting portion having a generally convex shape disposed toward the first frame member for engaging the periphery of and for seating the retaining means in the retaining portion of the first slot, and the retaining means is resiliently biased toward the first frame member. The entry portion of the first slot is preferably disposed at an edge of the second frame member.
In the preferred embodiment of the joint, the retaining means includes a spring washer and the first projection has an enlarged head spaced from the first frame member to form a stop for compression of the washer thereagainst, which washer may be a Belleville spring washer.
In other preferred embodiments, the entry portion of the first slot comprises an intersection of the slot with an admitting enlargement of the slot of size suitable to allow passage therethrough of the retaining means, and the projection retaining portion of the first slot may include a countersink providing a seat for the retaining means.
Yet another preferred embodiment includes an oversized resilient bushing instead of a Belleville washer, which bushing is mounted on the body of the first projection and forming part of the retaining means, the bushing having a generally cylindrical shape with an outside diameter greater than the width of the communicating portion of the first projection receiving slot for releasably retaining the first projection in the enlarged retaining portion of the first slot. The resiliency and size of the bushing and the size of the body of the first projection permit sufficient deformation of the bushing for forced passage of the bushing mounted on the first projection through the communicating portion of the first projection receiving slot, and the first projection has an enlarged head spaced away from the first frame member on the body of the first projection for retaining the bushing on the body.
The joint also includes a second projection on one of the frame members spaced from the location of the engaging of the retaining means and the retaining portion of the first slot. This second projection has a body adjacent its associated frame member and an enlarged head spaced therefrom for admittance of the other of the frame members therebetween. A second projection receiving slot in the other of the frame members receives the second projection and is disposed to retain it therein when the first projection is retained in the first slot retaining portion.
Preferably, the second slot has an entry portion thereof for entry of the second projection thereinto to dispose the second slot between the head of the second projection and its associated frame member, and has a portion connected to the entry portion and extending at a substantial angle to the extent of the first projection receiving slot for reception of the second projection when the first projection is retained in the retaining portion of the first slot by the retaining means.
In the preferred embodiment of the joint the entry portion of the second slot is disposed in the other frame member spaced away from the entry portion of the first slot at a different spacing from that between the first projection and the second projection when the first projection is retained in the retaining portion of the first slot by the retaining means.
Other embodiments of the joint may have a common entry portion for the first slot and the second slot, and the entry portion for the second slot may comprise an intersection of the second slot with an admitting enlargement thereof of size suitable to allow passage therethrough of the enlarged head of the second projection.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is A perspective view from the foot end of a Hollywood bed frame including several of the preferred embodiments of the present invention;
FIG. 2 is an enlarged foot-end elevational view of the adjacent portions of the separated bed frame members forming the nearest interlocking joint of FIG. 1;
FIG. 3 is a view similar to FIG. 2, showing the joint at an intermediate step of assembly;
FIG. 4 is a view similar to FIG. 2, showing the completely assembled joint;
FIG. 5 is a bottom view of the joint of FIG. 4;
FIG. 6 is an enlarged view of the joint of FIG. 4 as viewed along line 6--6 of FIG. 5, showing the projection within the communicating portion of the slot and the washer compressed accordingly;
FIG. 7 is an enlarged cross-sectional view of the joint of FIG. 4 taken along line 7--7 of FIG. 4 with the projection and Belleville washer in the enlarged retaining portion of the slot;
FIG. 8a is an enlarged perspective view of a shouldered rivet and Belleville washer retaining means ready for attachment to an interlocking joint member, and FIGS. 8b-d are enlarged elevational views of alternative retaining means embodiments;
FIG. 9 is a view similar to FIG. 4 showing an alternative second slot configuration;
FIG. 10 is a bottom view of the slot of FIG. 2 as viewed along the line 10--10 of FIG. 2;
FIG. 11a and b are foot-end elevational and horizontal cross-sectional views, respectively, of an alternative embodiment of the slot of FIG. 2;
FIG. 12 is a plan view of the interlocking joint between the center support rail and the head end cross rail of the frame of FIG. 1;
FIG. 13 is a bottom view of an alternative interlocking joint as used between the center support rail and the foot-end cross rail of the frame of FIG. 1;
FIG. 14 is a view similar to FIG. 4 of an alternative embodiment of the joint thereof;
FIG. 15 is an elevational view of the slotted member of the joint of FIG. 14;
FIG. 16 is a view similar to FIG. 4 of another alternative embodiment of the joint thereof;
FIG. 17 is a plan view similar to the left portion of FIG. 4, partially cut away to show a resilient bushing on a shouldered rivet in an alternative interlocking joint;
FIG. 18 is a cross-sectional view of the joint of FIG. 17 taken along the line 18--18 thereof;
FIG. 19 is a plan view of the joint of FIG. 17 showing the projection within the communicating portion of the slot and the bushing compressed accordingly;
FIG. 20 is a cross-sectional view of the joint of FIG. 19 taken along the line 20--20 thereof;
FIG. 21 is an enlarged perspective view of the bushing of FIGS. 17-20; and
FIG. 22 is a view similar to FIG. 4 showing a single-slot embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the interlocking bed frame members according to the present invention are shown in FIG. 1 as used in a typical Hollywood bed frame 20 having a pair of side rails 22, 24, a pair of cross rail assemblies 26, 28, and a center support rail 30, these members all formed basically from angle iron. The side rails 22, 24 are commonly connected to the cross rail assemblies 26, 28 by rivets 32 which allow the short end members 34, 36 of the cross rail assemblies 26, 28 to pivot in against the side rails 22, 24 for space-saving packaging or transport when disassembled from the mid-portions 38 of the cross rail assemblies 26, 28.
Interlocking joints 40, 42 constructed according to the preferred embodiments of the present invention as hereinafter described allow ready assembly and disassembly of the end members 34, 36 and the mid-portions 38. Center support interlocking joints 44, 46 similarly allow ready assembly and disassembly of the mid-portions 38 and the center support rail 30. Typically, the side rails 22, 24 and the center support rail 30 each have downwardly extending legs 48 attached thereto near the ends there of for supporting the bed frame 20 above a floor, and the casters 50 are attached to the lower ends of the legs 48 to contact the floor for easy movement of the frame 20 thereon.
For simplicity of disclosure, the single bed frame of FIG. 1 is shown with various interlocking arrangements according to different embodiments of the present invention incorporated in the single bed frame. It should be recognized that the present invention encompasses the use of only one of the joints on a bed frame as well as the use of more than one of each kind or different kinds on the same bed frame.
The interlocking joint 42 of the present invention in the form shown nearest the viewer in FIG. 2 is formed by mating projections from, and slots in, the mid-portion 38 and the short end member 36, respectively, of the cross rail assembly 26. Additional sets of slots as indicated by the numeral 51 in FIG. 1, at suitable spacings along the end members, are provided for adjustment of the bed frame to selected widths.
The angle iron short end member 36 has a "doll's head" first slot 52 formed vertically in the vertical flange 54 thereof near the free end thereof. The slot 52 intersects with the outside edge of the flange 54 thereby forming an entry portion 56 of the slot 52 at the intersection, and extends inwardly of the flange 54 therefrom forming a connecting and communicating portion 58 of the slot 52 from the entry 56 to an enlarged retaining portion 60 thereof typically of circular form larger than the communicating portion thereof and resembling a doll's head in silhouette. The angle iron mid-portion 38 of the cross rail assembly 26 has a first projection 62 thereon in the form of a shouldered rivet, as shown in FIG. 7, whose riveting shank 66 extends from the outside of the mid-portion 38 through the vertical flange 64 thereof by means of a clearance hole 68 therein located at a suitable distance from the right end thereof as explained hereinafter. The projection or rivet 62 has a body 70 whose diameter is sized for clearance within the communicating portion 58 of the slot 52, and a shoulder 72, part of the body 70 and disposed adjacent the flange 64, where the body 70 is necked down to form the riveting shank 66. The shoulder 72 is conventionally clinched tight against the outside of the midportion 38 by swaging a head 74 on the extending end of the riveting shank 66 on the inside of the midportion 38, at the same time expanding the shank 66 to a metal-to-metal fit inside the hole 68 to make the projection 62 essentially a permanent part of the midportion 38. A conventional rivet head 76 is provided at the projecting end of the body 70 and spaced from the flange 64 to retain a Belleville spring washer 78 mounted on the body 70 with its generally convex- or conical-shaped contacting portion 79 disposed toward the flange 64.
The head 76 is spaced from the flange 64 suitably to form a stop for the Belleville washer 78 on the body 70 so that when the body 70 of the projection 62 enters, or is received, within the slot 52, with the slot 52 disposed between the head 76 and the flange 64, the Belleville washer 78 will form a resiliently movable or compressibly resilient retaining means for engaging between the rivet head 76 and the periphery 80 of the enlarged retaining portion 60 of the slot 52 in a partially compressed condition, being compressibly expandable for seating movement into the retaining portion 60 for releasably preventing passage of the projection 62 from the enlarged portion 60 into the communicating portion 58 of the slot 52. Inherently, the well-known cross-sectional shape of the washer 78, as shown in FIG. 7, provides means disposed between the head 76 of the projection 62 and the contacting portion 79 of the washer 78 for compressible resilient biasing of the contacting portion 79 toward the end member 36. However, suitable force applied along the extent of the slot 52 will further compress the Belleville washer 78 against the head 76 to allow the projection 62 to move out of the retaining portion 60 into the communicating portion 58 and therethrough to and past the entry portion 56 for removal of the projection 62 from the slot 52. Reverse movement will cause like compression of the washer 78 to permit the projection 62 to enter the slot 52 and move therethrough to the retaining portion 60 for "snap-together" engagement for retention therein and removal therefrom.
In the preferred embodiment of the present invention as shown in FIGS. 3-5, the just-described projection and slot and retaining elements are combined with another projection and slot similar to those disclosed in the center support rail interlocking joint of the aforementioned U.S. Pat. No. 3,824,638. A second projection or rivet 82 has its riveting shank 84 extended through a clearance hole 86 in the vertical flange 64 of the midportion 38. This projection 82 is spaced away from the first projection 62 and the location of the engaging of the retaining means 78 and the retaining portion 60 toward and near the right end of, and lengthwise of, the midportion 38. The projection 82 has its shank 84 riveted to form a head 88 thereon, thereby fixing the body 90 of the projection 82 tight against its shoulder 92 and against and adjacent to the outside of the flange 64.
The enlarged head 94 on the body 90 of the projection 82 is spaced from the flange 64 for admittance of the vertical flange 54 of the short end member 36 therebetween. An L-shaped second slot 96 is formed in the flange 54 for receiving the body 90 of the projection 82 therein, one leg of the slot 96 being disposed to communicate and intersect with the outside edge of the flange 54 to form an entry portion 98 of the slot 96 for entry of the projection 82 thereinto to dispose the slot 96 between the enlarged head 94 and the flange 54 of the end member 36.
An angular portion 100 forming the other leg of the L-shaped second slot 96 extends at a substantial angle to the extent of the doll's head first slot 52 and is connected to the entry portion 98 of the slot 96 by the connecting portion 102 thereof for reception of the body 90 of the projection 82 for retention therein during the engaging of the retaining portion 60 of the slot 52 by the retaining means formed by the Belleville washer 78, i.e. when the first projection 62 is retained in the first slot retaining portion 60. The connecting portion 102 is disposed generally parallel to the communicating portion 58 of the doll's head slot 52.
The entry portion 98 of the slot 96 is spaced from the retaining portion 60 and the entry portion 56 of the slot 52 (and thereby from the location of the engaging of the retaining means or Belleville washer 78 and the retaining portion 60 during such engagement) at a different spacing from that between the first projection 62 and the second projection 82 when the first projection 62 is retained in the first slot retaining portion 60 by the retaining means 78.
As shown in FIG. 3, the interlocking joint 42 is assembled manually by slipping the body 90 of the projection 82 into the L-shaped slot 96 to the vicinity of the blind end of the angular portion 100 thereof (the angled-off corner 104 of the midportion 38 may be provided for clearance with the horizontal flange 106 of the short end member 36 during this assembly), and then slipping the body 70 of the projection 62 into the doll's head slot 52 until the Belleville washer 78 engages the retaining portion 60 thereof as shown in FIGS. 4 and 5. The extent of the communicating portion 58 of the slot 52 may be angled about 5° from perpendicularity to the outside edge of the flange 54 so that is approximates a segment of an imaginary arcuate slot centered at the blind end of the angular portion 100 of the slot 96. The extent of the angular portion 100 may be angled about 15° to the extent of the end member 36.
The engagement of the flange 106 at the left end thereof on top of the midportion 38 combined with the engagement of the projection 82 in the L-shaped slot 96 then locks the cross rail assembly 26 in straight disposition against the weight of the bedding or beings placed thereon while the engagement of the projection 62 in the doll's head slot 52 locks the cross rail assembly 26 from endwise telescoping movement. The size of the joint members, or projections, and the spacing between projections are all chosen so that the joint elements will not be deformed by normal weights or loads carried thereby. Thus the joint 42, once assembled, can only be disassembled by lifting up on the cross rail assembly to pivot the joint members about the projection 82 as shown in FIG. 3, and the detenting or retaining action of the retaining Belleville washer 78 in the retaining portion 60 of the doll's head slot assures that any such disassembly must be purposeful and not accidental.
Other embodiments of the present invention may be preferred for various reasons. In this regard, FIG. 9 shows an embodiment of an alternative interlocking joint 107 according to the present invention in which the entry portion 108 of a keyhole-shaped second slot 110 is formed by the intersection of its angular portion 112 with an admitting enlargement 114 thereof suitable to allow the passage of the enlarged head 94 of the second projection 82 therethrough. Thereafter, assembly of this joint 107 would proceed as previously described for the interlocking joint 42. The joint 107 may be substituted for the joint 42 and provides a stronger short end member 26 since there is no opening in the bottom edge of the vertical flange 54 thereof.
It is apparent that the interlocking joint 40 is merely an opposite hand version of the joint 42, and, of course, all the joints disclosed herein are subject to similar rearrangement.
Similarly, the embodiment shown in FIGS. 14 and 15 discloses a second alternative interlocking joint 116 wherein the doll's head slot and the L-shaped second slot are combined to form a composite "bird-billed" slot 118 in which a single common entry portion 120 serves a single common communicating portion 122 to admit both projections 62 and 82 suitably to the slot 118.
Where adjustment to more than one bedding width is not required perhaps the strongest and most economical embodiment of the invention is disclosed in FIG. 16, wherein a third alternative interlocking joint 124 is shown with its first projection 62 in its previously disclosed disposition on the midportion 38, as is the doll's head slot 52 on the end member 36; but the second projection 82 has its shank 84 riveted to the vertical flange 54 of the end member 36 with its body 90 and head 94 extending rearwardly therefrom. The projection 82 is located at a suitable distance to the right along the end member 36 from the slot 52 to mate with a straight second slot 126 opening to the right end edge of the vertical flange 64 of the midportion 38 and disposed at a substantial angle to the doll's head slot 52 during completed assembly of the joint. Assembly of the joint is accomplished essentially as explained hereinbefore, with the second projection 82 first slipped into the second slot 126 with the end member 36 angularly disposed to the midportion 38, and then the first projection 62 slipped into the doll's head slot 52 by conterclockwise rotation of the end member 36 about the projection 82 to the interlocking parallel engagement position with the midportion 38 as shown in FIG. 16.
A fourth alternative interlocking joint 46 is disclosed in FIG. 12, where the disposition of slots and projections is similar to that disclosed in the center rail support interlocking joint of the aforementioned U.S. Pat. No. 3,824,638, but the doll's head slot 52 in the midportion 38 and the Belleville washer 78 on the first projection 62 from the center support rail 30 have been introduced as components of the present invention. Construction and assembly of this center support rail interlocking joint 46 are obviously generally those of the joint 42 shown in FIG. 4.
Another embodiment of the invention is disclosed by the center support rail interlocking joint 44 shown in FIG. 13, where the first and second projections 62 and 82 are riveted to the midportion 38 with their bodies and heads on the underside of the horizontal flange 128 thereof, so that the midportion 38 is not weakened by slots in the central portion thereof. The doll's head first slot 52 opens to the end edge of the center support rail 30, while the straight second slot 126 opens to the side edge of the center support rail 30, with suitable spacings between projections and slots as explained hereinbefore for the same purpose of interlocking assembly to prevent shifting of the midportion 38 either laterally or lengthwise thereof with respect to the center support rail 30. Deliberate disassembly is possible, but only after overcoming the detenting engagement of the Belleville washer 78 carried on the projection 62 with the doll's head slot 52 by rotating the support rail 30 counterclockwise with respect to the midportion 38. This embodiment has the additional advantage that the slots, projection heads, and Belleville washer are all concealed and protected beneath the midportion 38 where bedclothes will not catch on them.
A further alternative embodiment of the doll's head slot 52 as shown in FIGS. 2 and 10 may take a form such as that shown in FIG. 11a and b, where the modified doll's head slot 130 includes a plain slot 132, an entry portion 134 where the slot 132 intersects the outside edge of an angle iron member, and a countersink forming an enlarged retaining portion 136 generally concentric to the slot 132 widthwise thereof and providing a seat for engagement with a retaining means such as a Belleville washer 78. Other embodiments of the doll's head slot are possible, such as the use of an admitting enlargement similar to the enlargement 114 of the keyhole slot 110 to allow passage therethrough of the retaining means to permit entry of the first projection into the doll's head slot.
The resilient movable or compressibly resilient retaining means formed by the Belleville washer 78 has a contacting portion 79 of conical shape but may alternatively be formed by other devices including contacting portions having generally convex shapes disposed toward the doll's head slot for engaging the periphery of the enlarged retaining portion 60 thereof and means for resilient biasing of the contacting portions toward the portion 60 as shown in FIG. 11b-d. A split helical, generally conical-faced washer 138 may be compressed axially between a first slot and the head 76 of the projection 62, a split helical washer or spring 140 behind a washer 142 with a contacting portion 143 having a generally convex shape may be used likewise, or a countersunk-type head 144 on a shouldered pin 146 may be biased into retaining engagement with a doll's head slot by a spring or split washer 148 disposed on the projection shank 150 of the pin 146 between a crosspin 152 therein and the back side of the projection-carrying member 154.
Alternatively, the resilient moveable or compressibly resilient retaining means may be a resilient generally cylindrical bushing 156 (as shown in FIGS. 12-21) mounted on the body 158 of an alternative first projection 160 from the flange 64. The outside diameter of the bushing 156 may typically be 0.375 inches, the inside diameter 0.325 inches, and the diameter of the body 158 may typically be about 0.280 inches, whereby the bushing 156 is oversized and may be squeezed or deformed out-of-round (as shown in FIGS. 19 and 20) over the body 158 sufficiently for permitting its forced passage through the communicating portion 58 (typically 0.340 inches wide) of a first projection receiving doll's head slot 52 in the flange 54 having an enlarged retaining portion 60 typically of about 0.360 inches diameter. The bushing 156 reverts resiliently toward its normal cylindrical shape when forced into the enlarged retaining portion 60 as shown in FIGS. 17 and 18, so that the bushing 156 releasably or detentingly retains the projection 160 within the retaining portion 60 of the slot 52 until forced back through the communicating portion 58 of the slot 52. The bushing may typically be formed from a plastic material such as nylon, polyester with glass fiber, or other suitable materials.
The projection 160 has a conventional rivet head 162 provided at the projecting end of the body 158 for freely retaining the bushing 156 thereon, for admitting the flange 54 between the head 162 and the flange 64, and for preventing significant flatwise separation of the flanges 54 and 64. The length of the bushing 156 is about the same as the thickness of the flange 54. An angled entry enlargement 164 of the slot 52 facilitates assembly of the oversized bushing 156 into the communicating portion 58 of the slot 52.
The bushing 156 may alternatively be used with the slot alternatives as shown in FIGS. 9, 12, 13, 14, and 16, or with a single projection 160 from a flange 64 and a single doll's head L-shaped slot 166 in a flange 54 to provide a suitably rigid self-interlocking joint 168, as shown in FIG. 22, where the horizontal flanges 106 and 170 of the rail portions 36 and 38 respectively become a functioning part of the joint 166, the rigidity being dependent on suitably spacing the projection 160 and the slot 166 from the respective lengthwise extremities of the rail portions 38 and 36. The alternative resilient retaining means of FIG. 8 might also be used with the slot 166.
While a number of alternative preferred embodiments have been disclosed above and illustrated in the drawings for disclosure purposes only, the possibilities of other constructions within the scope of this invention are by no means exhausted, and the disclosure herein is not intended to limit the scope of the present invention, which is to be determined by the scope of the appended claims. | Bed frame members are provided for quick, snap-together, interlocking assembly for preventing relative rectilinear motion between members without loose or screwthread parts. One member has a first slot with an enlarged retaining portion and a mating member has a projection thereon for entrance into the slot. The projection carries a Belleville washer having its conical convex face disposed for engagement with the slot for compression as the projection moves thereinto and for retaining engagement with the periphery of the enlarged retaining portion of the slot when the projection has been fully inserted in the slot. A second slot in one member has a portion disposed at a substantial angle to the first slot and receives a second projection disposed on the other member. When the second projection is positioned within the angularly disposed portion of the second slot, the Belleville washer may be detentedly engaged with the retaining portion of the first slot by relative rotary motion of the two members which are then locked from rectilinear motion relative to one another, and may be disengaged only by relative rotary movement to detentably disengage the retaining member from the retaining portion and from the first slot, after which rectilinear motions will disengage the second projection from the second slot. Instead of the washer, an oversized cylindrical resilient bushing may be used for deformation out-of-round when passing into the slot and detented engagement when the projection is fully inserted in the slot. | 8 |
RELATED APPLICATION DATA
[0001] This application is a non-provisional of application 61/375,789, filed Aug. 20, 2010, which is incorporated herein by reference.
[0002] In application Ser. No. 12/797,503, filed Jun. 9, 2010, and Ser. No. 12/855,996, filed Aug. 10, 2010, the assignee detailed a variety of technologies useful with smartphones and related systems, to help advance such devices into the realm of intuitive computing. The present technology concerns further improvements to the assignee's previous work, especially in the area of user interfaces.
[0003] The principles and teachings from these just-cited documents are intended to be applied in the context of the presently-detailed arrangements, and vice versa.
INTRODUCTION OF THE TECHNOLOGY
[0004] A variety of easy-to-use interface techniques have been devised for computer devices, and are now in widespread use.
[0005] One familiar interface involves interaction with web pages and other documents that incorporate hyperlinks (aka “links”).
[0006] In one particular scenario, when such a page is presented on a computer screen, hyperlinks are commonly shown in text of a different color (e.g., blue) and may be underlined. A user can move a mouse (or other pointing device) to position a mouse-controlled arrow cursor on, or near, the link. As the cursor approaches the underlined text, the arrow commonly switches to a hand cursor. This indicates to the user that the cursor is within an active zone. The user can then issue a “click” command with the mouse, activating the link and causing new information to be presented on the screen.
[0007] Such an arrangement is shown by the web page excerpt of FIG. 1 . The normal arrow cursor has changed to a hand cursor, and an underline has appeared under the blue hyperlinked text “DRMC.” Also shown by the dashed box in FIG. 1 is the “rollover zone” (sometimes termed the “hot area”) 102 that is associated with the link. When the arrow cursor enters this area, the cursor changes form, and a user click activates the link. (The extent of the rollover zone is not revealed to the user expressly; rather it is discovered by the user through use.)
[0008] Occasionally, when the cursor enters the rollover zone, a “tool tip” will appear on the screen. This is an annotation that is commonly used to provide the user further information about the link before it is activated.
[0009] Menus in application programs often work similarly. A user moves a mouse to position the arrow cursor on a button or other control. Instead of the cursor changing to a hand, the button/control is commonly highlighted—indicating that a click will invoke that function. Often a “tool tip” will be presented—giving additional information about the control at which the cursor is positioned.
[0010] It will be recognized that such interactions involve three stages. In the first, the arrow cursor is distant from a hyperlink/control, and clicking does nothing (at least as respects the hyperlink/control). This may be regarded as an “idle” stage.
[0011] In the second stage, the arrow cursor is within a zone associated with the hyperlink/control. In this position, something happens—the cursor changes form, or the control changes its appearance—alerting the user that the cursor is in position to activate something. This may be regarded as a “hovering” stage. No action is invoked by hovering unless/until the user issues a “click” command.
[0012] When the user issues a “click” command, the hyperlink/control is activated and takes an action. This third stage may be regarded as the “activated” stage.
[0013] Many of the UI principles familiar from desktop computers have counterparts on smartphones. For example, a link in a hyperlinked page is typically denoted visually (e.g., by a different color, and/or by underlining) so as to indicate its extra functionality. To activate the link, the user simply taps on the screen in a region on, or close to, the link. Likewise with a button or other control in a software program.
[0014] In the smartphone case, it will be recognized that there is no counterpart to the “hovering” stage. Until the user taps the screen, the presented page may be regarded as in an “idle” stage. When the issues a tap, it switches to an “activated” stage.
[0015] The user's “tap” operation on the smartphone screen is a form of gesture. Smartphones commonly support a variety of other gesture-based user commands. One is to sweep a finger down (or up) the screen—causing the displayed page of information to scroll down (or up). Another is to “pinch” with two fingers (placing the fingers on the screen, and moving them together). This causes the displayed page of information to be displayed at lower resolution—as by zooming-out. Conversely, the opposite operation, to “spread” with two fingers, causes the displayed page of information to be shown at greater resolution—as by zooming-in.
[0016] In one aspect, the present technology concerns counterparts to smartphone gestural user interface operations that can be used with printed documents and other tangible objects.
[0017] In another aspect, the present technology concerns mapping mouse-based user interface operations for use with camera-equipped smartphones.
[0018] The foregoing and additional features and advantages of the present technology will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows an excerpt of a web page, showing a prior art interaction technique using a mouse and a desktop computer.
[0020] FIG. 2 shows a page of classified advertising, as imaged by a smartphone camera and displayed on a smartphone screen.
[0021] FIG. 3A shows a pointer cursor presented on a smartphone screen.
[0022] FIG. 3B shows a hand cursor presented on a smartphone screen, together with a “tool tip” display of associated information.
[0023] FIG. 4A shows two gestures, involving momentarily tipping the top of the phone down or up.
[0024] FIG. 4B shows two gestures, involving momentarily twisting the top of the phone towards the left or right.
[0025] FIG. 5 shows how a printed page may be virtually divided into blocks, indicated, e.g., by row and column numbers.
[0026] FIGS. 6A and 6B show other styles of cursors presented on a smartphone screen.
[0027] FIG. 7 shows a first form of cover flow-style user interface, by which augmented classified advertising may be reviewed on a smartphone.
[0028] FIG. 8 shows a second form of cover flow-style interface.
[0029] FIG. 9 shows a “Magic Lens” interface.
DETAILED DESCRIPTION
[0030] The present technology is described in the context of digitally watermarked printed material, such as newspapers. However, the detailed principles are more generally applicable, e.g., requiring neither digital watermarks, nor printed material.
[0031] Digital watermark technology is used to embed auxiliary data into print, image or audio content. Exemplary watermarking arrangements are shown in the assignee's U.S. Pat. No. 6,590,996 and in published application 20100150434.
[0032] Commonly, digital watermarks are steganographic; that is, they escape attention. Often, watermarks are wholly imperceptible to humans, such as when pixels comprising an image are changed so subtly that the human eye literally cannot distinguish any difference. In other implementations, watermarking causes a change that is visible—but of such a character that a human viewer is not alerted that the marking conveys plural-bits of auxiliary data.
[0033] An example of the latter category of digital watermarking is background tinting. An inoffensive pattern of tiny dots, fine lines, or other features may extend across a piece of paper or other physical object—effectively giving the object an apparent tint. Such arrangement is particularly useful with newspapers and magazines. Different columns or other areas of text can be encoded with different backgrounds (conveying different watermark payload data), or an entire page can be encoded with the same payload. Examples are shown in the assignee's U.S. Pat. Nos. 6,985,600, 6,947,571 and 6,724,912, and in earlier-cited application Ser. No. 12/855,996.
[0034] FIG. 2 shows such an arrangement. Here, a smart phone camera is imaging a page of digitally watermarked classified advertising from a newspaper. (The paper is positioned about 6 inches from the camera.)
[0035] To access the functionality enabled by the watermark, the user activates a watermark reading mode of the smartphone. (This can be done in various ways known in the art, such as by a verbal instruction, a touch screen interaction, a physical button touch, etc.) In the watermark reading mode, a cursor arrow 112 appears over the imaged page of classified advertising, as shown in FIG. 3A . (The advertising imagery is not depicted in this and other figures, for clarity of illustration.)
[0036] Each enabled ad on the newspaper page has a rollover area associated with it. When the user moves the phone (or paper) so that the cursor arrow 112 is within the rollover area, the cursor changes form—to a hand cursor 114 . A tool-tip 116 may also appear. This is shown in FIG. 3B .
[0037] The presentation of the hand cursor is familiar to the user, from experience with conventional computers. The user understands that this indicates the device is now ready to take an action (e.g., obtain additional information) upon receipt of a signal from the user. Rather than using a mouse, however, the user in this particular arrangement provides the activating input signal by a gesture.
[0038] A number of gestures can be sensed by a smartphone, using built-in sensors (e.g., accelerometers, gyroscopes, and magnetometers). Gestures can also be sensed by analyzing apparent motion of features within imagery captured by the phone's camera.
[0039] FIG. 4A shows two exemplary gestures: tipping the top of the phone briefly down and then up—termed “tip-down,” and the reciprocal “tip-up” gesture. FIG. 4B shows two more—momentarily cocking the phone to the left a bit (e.g., 10-30 degrees) and then returning to its former orientation, termed “twist-left,” and the complementary “twist-right” motion. A great number of other phone movements can also be used as gestures signaling user intent to phone software. (Earlier work by the assignee in gesture interfaces is shown in U.S. Pat. No. 7,174,031.)
[0040] In the exemplary embodiment, a tip-down gesture is used to signal that the user wants to pursue a link associated with the hand cursor. When this gesture is sensed, the phone presents a screen of detailed information about the selected advertisement—commonly with a richer presentation of information than is available from the print ad alone, e.g., including photos, links to videos, etc.
[0041] The foregoing discussion described a simple interaction from the user's viewpoint. The following discussion provides underlying technical details of this exemplary embodiment.
[0042] When the watermark reader is activated, the software monitors data output from the phone's camera system. The software wants to read a watermark—any watermark—to learn something about the user's activity.
[0043] In an illustrative embodiment, the watermark detector does not try to read a watermark unless imagery of a suitable quality is available. If suitable imagery is available, it is buffered and analyzed to determine whether a watermark appears present. If so, a watermark reading operation is performed.
[0044] Various assessments can be performed in this regard. One is to consider the phone's motion. If the phone is moving actively, the imagery is probably too blurry to be useful for watermark reading. Phone motion can be judged from sensor data (e.g., accelerometer, gyroscope). If the indicated motion exceeds a threshold, the captured imagery may be disregarded as of little use. In contrast, if the motion is below a threshold, the user is holding the phone steady enough that imagery suitable for watermark decoding may be captured.
[0045] Instead of inferring image blurriness/sharpness from other sensors, the pixel data itself can be examined. Sharp imagery (as contrasted with blurry imagery) tends to be characterized by relatively higher contrast, stronger edges, and higher frequency content. Image processing techniques familiar to artisans can be applied to pixel data in order characterize one or more of these parameters, and derive a metric indicating relative image quality. Again, only if the quality is above a threshold is watermark analysis performed.
[0046] Yet another technique for assessing image quality is to employ tools provided with the phone. The operating system of the Apple iPhone 4, for example, exposes various parameters that identify when the camera system's auto-focus portion has achieved focus-lock, when its auto-exposure portion has set a suitable exposure, and when its white balance portion has set a suitable white balance. In particular, the “CoreVideo” class of interfaces provided by the operating system expose such information, and can be invoked to pass such data to the watermark reader. Watermark detection/reading may be performed only if one or more of these (e.g., at least auto-focus lock) indicates suitable image quality.
[0047] When promising imagery is available, further testing may be applied before watermark reading is started. For example, the imagery may be checked for a dynamic range that is likely to allow watermark decoding. Similarly, the imagery can be checked for “flatness”—indicating a relative lack of features (as may occur if the camera is pointing to a blank wall), suggesting no watermark is present. (The assignee's U.S. Pat. No. 7,013,021 details useful screening strategies.)
[0048] When a frame of imagery is available that appears suitable, the software commences watermark analysis, e.g., using the techniques detailed in the assignee's U.S. Pat. No. 6,590,996 and published application 20100150434. (In some implementations, the frame may be a composite—formed using pixel data from two or more frames.)
[0049] The decoded watermark payload data may be of different types. In one arrangement it comprises a page ID, and a block ID. The page ID is a unique identifier that is associated with a particular newspaper page (e.g., page D5 of the Oregonian , metro edition, Aug. 20, 2010). The block ID indicates a particular region of the page.
[0050] As shown in FIG. 5 , a page can be regarded as composed of an array of square tiles 202 a , 202 b , etc. Each tile, or block, can be identified by a number. In the illustrated arrangement, each block is identified by two numbers—a row number and a column number.
[0051] Thus, a decoded watermark may have a payload including a page ID of 7B32A9, and a block ID of {1,4}. The former takes 24 bits to represent; the latter may take 8 bits. Larger or smaller watermark payloads can of course be used.
[0052] As soon as the watermark software has successfully read a watermark from captured imagery, it sends the decoded payload to a remote database system, and requests corresponding data in return. The database system includes information stored by the newspaper about watermarked pages and their contents (or includes pointers to other remote systems where such information is stored). From such remote repository, the smartphone requests information about the page and its contents.
[0053] The returned information indicates the user is looking at page D5 of the Aug. 20, 2010 Oregonian —and further indicates a particular tile region of the page. Assuming that network considerations permit, the returned information desirably also includes summary information about each advertisement on the page—together with links where additional information for each ad is stored. (Provision of such information in anticipation of later possible use speeds system response if the user later decides to view or use such information.)
[0054] To recap, in the exemplary embodiment, all of the above operations may occur as soon as a first sharp frame of imagery is available to the watermark decoder portion of the phone. No user action—other than activating the watermark reader—is required. (As detailed in earlier-cited application Ser. Nos. 12/797,503 and 12/855,996, user activation of watermark-reading functionality is not required in other embodiments. Instead, the phone may always be alert to possible digital watermarks in captured imagery.)
[0055] Once the phone has received information about the newspaper page from the remote system, consideration can then be given to the position of the cursor 112 on the page. As detailed in the earlier-referenced patent documents, the detailed digital watermark includes embedded registration data allowing the watermark software to discern a 6D pose of the watermarked object (i.e., the newspaper page).
[0056] More particularly, the watermark detector can sense the rotation of the captured imagery from its originally-encoded orientation, the scale of the watermark from its original size (related to viewing distance), and the translation of the sensed watermark pattern from the watermark's origin (further noted below). The viewing angle (expressed as offset from perpendicular) can also be estimated.
[0057] In the detailed arrangement, each block 202 is tinted with a unique watermark pattern tile that conveys the page ID, and a block ID for that block. (Although each block has a slightly different payload, they all appear unobtrusively uniform to a human observer.) As detailed in the cited documents, an illustrative watermark pattern tile is formed of 128×128 square sub-regions (termed watermark elements, or “waxels”). These sub-regions are located vertically and horizontally at a spacing of 66 to the inch. (In magazines, higher waxel density, such as 150 to the inch, may be used.) Thus, in this particular embodiment, a block 202 is 1.94 inches on each side. Each watermark tile has an origin at the upper left corner. (The watermark origin is the reference point from which the translation part of pose is related, as waxel offset in X- and Y-.)
[0058] The block 202 a , in the upper left corner, has its top edge at the top of the page, and its left edge at the left page margin (assuming the watermark tinting goes to the edges of the page). Block 202 a , next to it, again has its top edge at the top of the page, but its left edge 1.94″ from the left margin.
[0059] The upper left corner (origin) of each block 202 can similarly be determined from its block ID, which indicates row and column position. For example, block {3,2} has its upper left corner 3.88″ down from the top of the page, and 1.94″ from the left margin of the page. Thus, from the block ID, together with the pose data discerned from the watermark, the position of the arrow cursor 112 in FIG. 3A , within the printed page, can be resolved to 1/66 th of an inch, both vertically and horizontally. (The depicted cursor is at the center of the smartphone screen, although this is not necessary.)
[0060] The information returned from the remote database can be organized in terms of the X- and Y-position of each advertisement on the page (in inches, waxels, or otherwise). For example, the returned information can include coordinates for a rollover zone for each advertisement.
[0061] If the cursor arrow is found to have its tip within a rollover zone (or if the paper or camera is moved so as move the tip within such a zone), the software responds by changing the cursor to the hand form shown in FIG. 3B . The information returned from the remote database, associated with this rollover zone, can include a tool tip 116 (e.g., “1967 Mustang”) indicating the subject or other information associated with this part of the page.
[0062] The information returned from the remote database can also include the text of the printed advertisement, and typically includes other expanded information as well. If the operating system reports receipt of a user gesture (e.g., a “tip down” gesture), all such expanded information can be presented to the user.
[0063] (The attentive reader will note that the “top down” gesture deflects the camera aim from its original position, and results in the capture of blurred imagery—assuming frames are captured in free-running fashion. To facilitate use of phone-moving gestures in connection with camera imagery, the phone desirably has a first-in, first-out memory buffer where it stores recent frames of imagery—of a quality suitable for watermark detection. When a gesture is sensed that implicates camera imagery, this buffer is consulted to retrieve a frame of imagery that was stored before the gesture-associated movement began (typically the last-stored). The gesture-indicated operation is then performed by reference to this recalled frame of imagery.)
[0064] In one particular embodiment, when a hand cursor is displayed on the screen, and a tip-down gesture is sensed, the earlier-retrieved expanded information is presented on top of the camera imagery. (The imagery may be dimmed or made transparent, and/or the expanded information may be presented in a box that supplants the camera imagery in its area.) Alternatively, the camera imagery may be removed from the screen, and the expanded information may be presented alone.
[0065] In some implementations, the information returned from the remote database does not include all the expanded information for each advertisement on the page, but includes only links to such information. In this case, when the arrow cursor changes to a hand cursor, the smartphone can automatically use the link associated with that rollover zone to retrieve the expanded information (from wherever it is stored)—without waiting for a user gesture that triggers display of such information. The hand cursor, alone, is enough expression of user interest to warrant retrieval of the associated information.
[0066] As just noted, display of the hand cursor indicates at least a low level of user interest in that part of the printed page. (If the user then gestures, this expresses a still higher level of interest.) Such information is useful to various parties, e.g., the newspaper publisher, advertisers, third party consumer demographic repositories such as Nielsen, etc. Accordingly, certain embodiments of the present technology store information (a data log) indicating the printed content over which the user's smartphone at least momentarily rendered a hand cursor. Such action indicates likely user hovering over such point (e.g., to review a displayed tool tip). This logged information (which can also include other information, such as how long the user hovered over such ad, and whether the ad was pursued further, as by gestural invocation) may be provided to interested parties, e.g., in exchange for payment to the user, or in accordance with terms of service of the software. Those parties, in turn, can take action based on such “audience measurement” information, e.g., generating and providing reports to interested parties, setting different prices for advertising at different locations in the newspaper, etc. (E.g., if data shows that the upper outer corner of the newspaper pages are those most commonly noted by users, then advertisements placed at such locations may warrant higher insertions rates.)
[0067] FIG. 7 shows a “cover-flow” presentation of classified advertising information on a screen of a smartphone, in accordance with another aspect of the present technology. In such embodiment, expanded information for one advertisement is presented prominently on a virtual pane 250 a displayed near the center of the screen. Above and below (or to the right and left, depending on implementation) are partial views of other panes 250 b - 250 g . For these panes, less information is presented—such as just a title.
[0068] As the user moves the smartphone camera, panning up or down a column of advertising, the panes of the cover-flow interface flip in animated fashion, revealing details about adjoining advertisements. If the expanded information for the full page of advertising has been received from the database, then such panning yields a fluid, rippling display—akin to a magician artfully manipulating a deck of cards. But in this case the cards serve as lenses revealing further information about topics of interest to the user, all based on print media.
[0069] Again, still more information may be available. The pane 250 a shown in FIG. 7 , for example, includes a single picture, and limited text. While this pane is displayed, the user may make a tip-down motion with the phone, triggering presentation of still additional information—such as a gallery of other pictures, video, detailed specifications, etc. Again, such information may have been earlier downloaded from a remote store, and cached for ready delivery when so-requested by the user.
[0070] Other gestures may trigger other actions. For example, a tip-up gesture may cause the expanded information to be added to a memory for later review; a twist-left gesture may cause the expanded information to be emailed to a default destination, or posted to a social networking page associated with the user, etc.
[0071] The cover-flow interface of FIG. 7 , like some others, faces a screen real estate issue. The viewer typically is less interested in the imagery captured by the smartphone, than in the expanded information to which such imagery enables access. Yet the imagery is a useful aid to navigation of the print media. As a compromise, the cover-flow interface can optionally include a virtual window 252 that allows the user to see an excerpt of imagery captured by the camera, as if visible from behind the cover flow. (Such imagery is omitted from FIG. 7 for clarity of illustration.)
[0072] The depicted window 252 is not at the center of the display screen. Yet it is the center of the display screen where the user commonly expects to find the cursor that points to items of interest. In the depicted arrangement the window 252 presents a rectangular excerpt of imagery taken from the center of the camera's field of view. A cursor icon can be presented in the middle of this window, pointing at imagery at the center of the camera's field of view. By such arrangement, the user retains the spatial context provided by a cursor overlaid on the printed imagery towards which the camera is directed, while still providing the other benefits of the cover-flow interface. (This rectangular window 252 may be stationary and persistent through the flipping animation of the different panes, as the camera is moved up or down the page.)
[0073] FIG. 8 shows a second cover-flow interface. In this embodiment, a window 254 is again provided for the display of captured imagery. In this case, however, the window extends essentially the full height of the display—allowing for a taller presentation of newspaper imagery. (Again, the presented imagery is taken from the center of the camera's field of view.) This particular implementation does not present a cursor within the window 254 .
[0074] The embodiment of FIG. 8 is well suited for use with static, rather than live, camera imagery. The software can store a static image captured from the printed page, allowing the user to thereafter navigate by reference to this stored image. Such navigation can be done much later. For example, the user may capture imagery from a newspaper while standing in line in a coffee shop, and hours later—during lunch—explore based on the earlier-captured imagery.
[0075] In particular, the user can navigate by tapping the displayed imagery in window 254 at a desired point, or by sweeping a finger up or down the window. This latter action causes the cover-flow animation to activate, successfully flipping different panes into view.
[0076] Although the window 254 is of limited width, the user can also sweep a finger sideways across the window. This causes the underlying imagery to move with the finger (as is familiar from the Apple iPhone and the like)—revealing new parts of the captured imagery. For example, by sweeping a finger to the left, this causes new imagery to enter the window from the right, e.g., exposing a new column of advertising that the user can then browse. Such imagery can also be manipulated with “pinch” and “spread” gestures—causing the imagery to be presented at greater resolution (i.e., focusing on a smaller area) or lesser resolution (i.e., allowing a larger area to be seen). Again, such resized or repositioned imagery can be used as the basis for user browsing, using the cover flow paradigm.
[0077] In still other implementations of the cover-flow interface, the imagery from the camera may be displayed full-screen, but dimmed, or with reduced contrast. The depicted cover-flow arrangement may then be superimposed on this background—with a degree of transparency providing a sense of visual context with the underlying camera imagery.
[0078] It will be recognized that on-going interaction with captured imagery from the printed object is not required. Once a first watermark has been decoded from any point on a newspaper page, the smartphone can retrieve expanded information for all content on the page (indeed, for all content in the newspaper). The paper itself is not, strictly speaking, thereafter needed.
[0079] For example, the interface of FIG. 8 may omit the window 254 . To browse ads on the imaged page of the paper, the user can simply make a sweeping scroll-up or scroll-down gesture with a finger on the screen. The expanded information corresponding to the advertising, downloaded from the remote computer, can be recalled from the memory, in order of their spatial positions, and presented in animated fashion using the cover-flow interface. The user can switch to an adjoining column of advertising by a sweeping finger motion to the left or right on the screen.
[0080] Moreover, the information presented on the display needn't be ordered in accordance with the spatial positions of the corresponding advertisements on the printed page. The information can be sorted by any other metadata, such as price, distance to the seller (e.g., estimated by telephone exchange or zip code), automobile model year, automobile color, etc. Such options can be defined by auxiliary menus, which may be invoked using conventional UI techniques.
[0081] In interfaces that make use of imagery corresponding to the printed page (e.g., FIGS. 7 and 8 ), it will be recognized that such imagery needn't all be captured by the smartphone. Once a first image of the page has been captured by the smartphone, the watermark reveals particulars about the publication and page number. Pristine imagery for the entire page (or for the entire publication) can be downloaded from the remote database, and thereafter be used instead of the (typically lower quality) imagery captured by the smartphone camera.
[0082] Again, a log detailing all of the information presented on the smartphone screen, and the duration of each such impression, can be collected and provided to third party users, such as Nielsen, if desired.
[0083] Smartphone cameras enable still other functionality. Consider, in particular, use of touch screen gestures.
[0084] Touchscreen gestures are useful UI constructs, but are best suited for non-portable devices. When used with a portable device, such as a smartphone, one hand typically holds the phone, and the other hand performs the touchscreen gesture. But it is not always convenient to devote both hands to smartphone operation.
[0085] In accordance with other aspects of the present technology, this two-hand modality can be avoided. Instead of gesturing with a finger (or fingers) on a touch screen, a corresponding command is issued by moving the phone.
[0086] Consider the “spread” gesture, which causes the display to zoom-in on an image being displayed. As is conventional, two hands are required, one to hold the phone, and the other to execute the “spread” gesture.
[0087] Camera imagery can be employed to effect such operation single-handedly. The user simply moves the phone's camera towards whatever it is pointing to. Software in the phone performs feature tracking on imagery captured by the phone, and notes features moving towards the edge of the frame as the camera is physically moved towards an object. The object being imaged, and the camera data, need not be displayed on the screen. Instead, the stream of captured camera imagery is a proxy for finger gestures on the touch screen. By noting that the user is physically zooming the camera towards a subject, the software performs a corresponding zooming operation on whatever information is displayed on the smartphone screen—just as it did in the prior art in response to a spreading touch gesture.
[0088] Conversely with a pinching gesture. Movement of the camera away from a subject serves in lieu of the second hand performing the pinching gesture on the touch screen.
[0089] Rather than perform a feature tracking operation on the captured imagery, the smartphone may detect changing scale of a digital watermark included in a sequence of frames of captured imagery. If the scale increases, this indicates that the user is moving the phone towards a watermarked object—signaling an intended zoom-in operation on whatever information is being displayed on the screen. Conversely, if the scale decreases, this signals an intended zoom-out operation.
[0090] Although not yet enabled on the iPhone, the Apple Mac Book Pro has another touch screen gesture that rotates whatever information is displayed on the screen. This gesture involves placing two fingers on the screen, and then twisting the finger stance—while maintaining the inter-finger distance substantially constant.
[0091] In analog, a smartphone user can simply rotate the device, which serves to rotate the imagery captured in the camera's field of view. Such rotation can again be sensed from feature tracking in the captured imagery, or by reference to orientation information available from a 6D pose vector produced by the noted watermark detector.
[0092] The smartphone mode in which it interprets camera data as a proxy for touch-screen gestures can be launched by various known arrangements, such as spoken command, button press, whole phone gesture (e.g., FIGS. 4 A/ 4 B), or even a touch-screen gesture. It can be discontinued by similar means.
Magic Lens
[0093] Magic Lens (aka “Toolglass”) is a user interface (UI) concept originally developed by researchers at Xerox PARC, that never became viable due to perceived impracticality. In accordance with aspects of the present technology, such UI is implemented in a highly practical form.
[0094] The Magic Lens arrangement is a two-handed UI. With one hand, the user operates a first pointing device (e.g., a mouse). This device moves a gridded palette of tools, commonly presented as a transparent overlay, on the user's desktop. One tool may be Copy. Another may be Paste. Another may be Email. Another may be Print. Etc.
[0095] The user manipulates the gridded tool overlay so that a desired tool (e.g., Print) is positioned over a particular object to which the tool is to be applied (e.g., a desktop icon representing a file).
[0096] Then, with the other hand, the user operates a second pointing device (e.g., a second mouse), which moves a cursor on the screen. The user positions this cursor to point at a particular tool within the displayed gridded array of tools. (Recall that the user earlier operated the first pointing device to position the tool grid with the Print tool overlying the desktop file icon.) Once the cursor has been positioned over the Print tool, the user clicks the second mouse. This causes the file represented by the icon to be printed.
[0097] This arrangement involves the spatial confluence of three objects: a feature on the user's original screen (e.g., desktop), in appropriate spatial alignment with a particular tool in the gridded palette, together with the mouse cursor.
[0098] Such arrangement is detailed in Xerox's U.S. Pat. No. 5,617,114, and in a number of journal publications. Two are by Xerox's Bier, et al, namely Toolglass and Magic Lenses: The See-Through Interface, Proc. of SIGGRAPH '93, 73-80 (attached to provisional application 61/375,789 as Appendix A) and A Taxonomy of See-Through Tools, SIGCHI '94 (attached to provisional application 61/375,789 as Appendix B).
[0099] The impracticality of this arrangement proved to be its two-handed operation. Such style of man-machine interaction was found to be ill-suited for most work environments.
[0100] In accordance with this aspect of the present technology, such impracticality is overcome by using the smartphone camera in a manner analogous to the first pointing device, and using the user's thumb (or other finger) in a manner analogous to the second pointing device.
[0101] FIG. 9 shows an example. In this mode of operation (which can be invoked by the user in conventional ways), associated software presents a gridded palette of tools as an overlay (optionally, transparent) on top of imagery captured by the smartphone camera. Each tile in the grid has a function associated therewith, identified by a label or other indicia. For example, tool tile 302 is labeled with the function PRINT. Each tile may also include some indicia by which the user can precisely aim the function to indicate with a particular point in the imagery, although such feature is not strictly necessary. In the illustrative embodiment a “+” (crosshair) is used.
[0102] The user positions the phone camera so that the desired function tile overlays a desired excerpt of imagery, e.g., a particular newspaper article or classified ad (not shown for clarity of illustration). The user then taps the desired function tile (e.g., PRINT) using a thumb, or other finger. This tap is sensed by the touchscreen interface provided by the smartphone operating system, and triggers execution of the selected function, applied to the object denoted by the “+”. In this case, the classified advertisement is printed on the default printer.
[0103] There are numerous variations on this theme. Indeed, essentially all of the operations, and constructs, detailed in the cited Xerox documents can be implemented by an artisan with a camera-equipped smartphone based on the foregoing description, without undue experimentation. These principles can likewise be applied to known two-handed UIs of other design—with camera position being one degree of control, and the user's tap at a desired location of the screen being another degree of control.
[0104] Other features and arrangements not contemplated in the Xerox documents, but taught herein and in the documents incorporated by reference, can similarly be applied using such arrangement, again without undue experimentation.
[0105] For example, the PRINT function just noted need not print just the text of the classified advertisement as published in the newspaper being imaged by the user. Instead, the expanded information obtained from a remote database—based on decoded watermark data, can be printed. In this case, the printed version of the advertisement is more detailed than the original.
[0106] Similarly, the camera imagery tapped by the user need not be “live.” Instead, after positioning the camera to overlay the tool palette at a desire position on the live imagery, the user can issue an instruction to capture a static frame (e.g., by a gesture, or spoken instruction). Once the frame is thereby frozen, the user can tap the desired tool tile to launch the desired operation—without worry that such manipulation might cause the tool palette to shift relative to the captured imagery.
[0107] A great number of other such variations are well within the skill of the artisan from the present disclosure.
Concluding Remarks
[0108] From the foregoing, it will be recognized that the present technology extends concepts of user interfaces, and camera usage models, for smart phones. In one aspect, a graphical user interface for print media is provided. Moreover, such user interface leverages users' prior experiences interacting with online web pages, making such interaction intuitive—even without any instruction
[0109] It will be recognized that the detailed arrangements are exemplary only. Actual implementations are likely to differ in numerous details, such as with different iconography, different gesture vocabularies, additional actions and features, etc. Thus, the described arrangements should not be taken as bounding our technology, but rather as illustrating the inventive features in sample implementations, among myriad possible implementations.
[0110] Likewise, although described primarily in the context of classified advertising, it will be recognized that the same principles are also applicable in other contexts, including other print content, such as news articles, photographs, display advertising, etc.
[0111] Consider, for example, a news article. A newspaper may highlight a word or phrase within an article, using a distinctive typeface or other presentation, to indicate to the reader that expanded content is available. Such a graphical clue is familiar to users because of widespread use of such clues on web pages to denote hyperlinks. Indeed, the presentation adopted by the newspaper can mimic web page hyperlinks, such as by printing such words in blue color, and/or underlined. (Bolding may also be used.)
[0112] As before, as soon as the user captures a single suitable image frame from anywhere on the page, the publication and the page can be identified. Expanded content for the page can be downloaded to the smartphone, and cached for ready user access. Again, the downloaded information includes data defining the extent of the rollover zone associated with each item on the page. The size of the rollover zone can be smaller or larger, depending on whether the number of separately linked words/phrases is greater or smaller. If an article has just a single linked phrase (e.g., the lead-in sentence), the rollover box can be defined to encompass the entirety of that article on the printed page. At the other extreme, each word in an article may have its own link to (potentially different) expanded content.
[0113] In other arrangements, the availability of linked content is not indicated by highlighted words or phrases. Instead, users may become accustomed to find that essentially all print media has associated linked content. Holding the phone relatively stationary over any print media may result in discovery of the background tint at that location, causing the cursor to switch to a hand, and signal that the linked content is ready for display at the user's instruction. A tool tip foreshadowing the information available from the linked data may be presented, to help the user decide whether to follow the link.
[0114] Likewise with photographs published in a newspaper. Consider a photograph of President Obama and family. Positioning the smartphone so that the cursor 112 is over one of the children's faces may cause a tool tip to appear, e.g., identifying the child by name. Gesturing with the phone can then summon expanded information, such as the Wikipedia page for that child. (Watermarking in photographic imagery may be by tinting, or the halftone elements comprising the picture may be subtly modified to convey the auxiliary data—putting more signal energy where it is relatively less visible, and putting less energy where it may be relatively more visible, as is familiar to artisans.)
[0115] The cover-flow interface is useful not just with classified advertising, but also with newspaper articles. Again, by capturing a single image of any part of any newspaper page, the entire newspaper contents may be downloaded to the smartphone. The headline and lead paragraph (and optionally a photo) from each article may be presented on a cover flow pane. The user can review an electronic counterpart to the newspaper by sweeping a finger across the screen, flipping through successive panes/stories.
[0116] Again, the panes may be ordered in correspondence with their order in the printed newspaper, but this is not essential. Other orderings can be used. One ordering relies on user profile data, e.g., based on historical usage patterns. If the user historically spends more time reviewing stories involving local government and the Seattle Mariners, then such articles can be presented among the first panes shown. Conversely, if the user seems to have no interest in articles about reality shows, and obituaries, these materials can be put at the end of the cover-flow article order.
[0117] Sometimes the user may be rushed, and not able to explore all the expanded content made available by such technology. In one implementation, the phone stores expanded content for each item over which the user causes the cursor to hover (i.e., changing to a hand cursor). This information is kept in a virtual briefcase, or other data structure, in which it can be readily reviewed when the user has more leisure.
[0118] The artisan will recognize that this technology has natural social networking implications. One is that the user's history in reviewing expanded content may be posted to a social networking site, and shared with selected ones of the user's friends. Typically, such history is filtered before posting, based on profile settings or stored rules. An exemplary user may specify that the social networking page can identify (and link to) the three articles that the user spent the longest time reviewing within the past week, within the news section and/or opinion sections of the newspaper.
[0119] FIGS. 6A and 6B show other forms of cursors 402 , 404 that can be employed with the present technology. In the prior art, such cursors have been presented in consistent, unchanging fashion, e.g., to indicate the zone of imagery on which the camera tries to focus. In accordance with aspects of the present technology, such cursors can serve to convey information about the camera system, or the captured imagery, to the user.
[0120] For example, progress in achieving focus—or a state of focus lock—can be signaled by changes to the cursor, such as by changing its size (e.g., becoming smaller as focused is gained). When focus lock is achieved, the cursor may change color.
[0121] Alternatively, the color of the cursor may be animated to signal progress in achieving focus, e.g., starting red, and progressing through a sequence of other conspicuous colors until it ends with black when focus is achieved. If focus is not achieved, the color can revert to its original red (or to another color).
[0122] Similarly, the cursor may flash at a rate dependent on a camera or image parameter. Or it may be animated (e.g., in a racing lights fashion) at a speed dependent on such a parameter.
[0123] Even the shape of the cursor may be modulated, e.g., with the straight lines taking a wavy or otherwise distorted form, with the amplitude and/or frequency of the distortion effect indicating a parameter of potential interest to the user.
[0124] Different of these effects can also be combined.
[0125] While focus was cited as an example of a parameter of potential interest to the user, others include auto exposure, white balance, degree of camera shake, the relative quality of the image for decoding a watermark, etc.
[0126] Another parameter of potential interest is viewing angle. Watermark detectors work best when looking straight down on the watermarked medium. If a watermarked page is viewed from an angle, the time required to decode the watermark increases.
[0127] The viewing angle can be estimated from the imagery—both from the watermark itself, and also from other visual clues (e.g., square boxes become distorted into trapezoids).
[0128] If the camera is looking straight-down onto the page, the cursors may be presented as shown in FIGS. 6 A/ 6 B. (Or, better still, in square- rather than rectangular-form.) If the camera is viewing the page from an angle, a corresponding side of the cursor can be presented in exaggerated size. The user will naturally tend to move the phone so that the cursor is presented in a symmetrical fashion, with its top and bottom sides all of equal dimension, indicating optimum viewing.
[0129] Alternatively, such viewing angle information can be conveyed by other modifications to the displayed cursors, including those reviewed above in connection with focus, etc.
[0130] The cited patent documents provide additional details that can be used to implement embodiments of the present technology. The described functionality can be implemented in software form by an artisan from the present disclosure, without undue experimentation. Details concerning the iPhone device, including its user interface, are provided in Apple's published application 20080174570.
[0131] To provide a comprehensive disclosure without unduly lengthening this specification, applicants incorporate-by-reference the patent applications and documents referenced above. (Such materials are incorporated in their entireties, even if cited above in connection with specific of their teachings.) These references disclose technologies and teachings that can be incorporated into the arrangements detailed herein, and into which the technologies and teachings detailed herein can be incorporated. The reader is presumed to be familiar with such prior work. | Certain aspects of the present technology concern counterparts to smartphone gestural user interface operations that can be used with printed documents and other tangible objects. Other aspects involve mapping mouse-based user interface techniques for use with camera-equipped smartphones. A great variety of other features and arrangements are also detailed. | 6 |
This is a division of application Ser. No. 490,842 filed May 2, 1983, now U.S. Pat. No. 4,532,242.
TECHNICAL FIELD
The present invention relates to compounds which are known as triazolo[4,3-c]pyrimidines, and more specifically as 1,2,4-triazolo[4,3-c]pyrimidines. The pharmacological use of these compounds as bronchodilators, pharmaceutical compositions containing these compounds, and synthetic intermediates for the preparation of certain of these compounds are also within the scope of the invention.
BACKGROUND OF THE INVENTION
Some 1,2,4-triazolo[4,3-c]pyrimidines are known to the art. Certain 3-amino-1,2,4-triazolo[4,3-c]pyrimidines are disclosed in the patents discussed below:
United Kingdom Pat. No. 859,287 discloses what are believed to be the compounds 3-amino-7-methyl-5-methythio-1,2,4-triazolo[4,3-c]pyrimidine and 3-amino-7-chloro-5-methyl-1,2,4-triazolo[4,3-c]pyrimidine.
United Kingdom Pat. No. 873,223 broadly describes 6-hydrazinylpyrimidines which may contain alkyl, substituted alkyl, alkenyl, cycloalkyl, alkylthio and halogen sustituents in the 2-, 4- and 5-positions. These pyrimidines are used as intermediates in the preparation of 1,2,4-triazolo[4,3-c]pyrimidines.
United Kingdom Pat. No. 898,408 discloses 3-amino-1,2,4-triazolo[4,3-c]pyrimidines which are substituted on the pyrimidine ring at the 5-position by an alkyl, alkylthio, or amino substituent, at the 7-position by an alkyl, halogen-substituted alkyl or halogen substituent, and at the 8-position by hydrogen or an alkyl or alkenyl substituent. This patent also broadly describes, as intermediates, 6-hydrazinylpyrimidines which may contain alkyl, alkylthio or amino in the 2-position, alkyl, substituted alkyl or halogen in the 4-position, and hydrogen, alkyl or alkenyl in the 5-position.
The following related articles disclose the synthesis of certain 1,2,4-triazolo[4,3-c]pyrimidines as intermediates in the preparation of 1,2,4-triazolo[1,5-c]pyrimidines and as potential branchodilators.
G. W. Miller et al., J. Chem. Soc., 1963, 5642, discloses 1,2,4-triazolo[4,3-c]pyrimidines which are substituted at the 3-position by amino or imino substituents, and on the pyrimidine ring by alkyl substituents or alkyl and alkenyl substituents.
G. W. Miller et al., J. Chem. Soc., 1963, 3357, discloses the compound 3-hydroxy-7-methyl-5-n-propyl-1,2,4-triazolo[4,3-c]pyrimidine.
W. Broadbent et al., J. Chem. Soc., 1963, 3369, discloses the compound 3-mercapto-7-methyl-5-n-propyl-1,2,4-triazolo[4,3-c]pyrimidine.
Still other 1,2,4-triazolo[4,3-c]pyrimidines are disclosed in the following articles and patent:
Shiho et al., Yakagaku Zasshi, 1956, 76, 804, discloses 1,2,4-triazolo[4,3-c]pyrimidines which are substituted at the 3-position by alkyl or phenyl substituents, and on the pyrimidine ring by both methyl and methoxy substituents.
Temple et al., J. Org. Chem., 1968, 33, 530, discloses the compound 8-amino-7-chloro-5-triazolo[4,3-c]pyrimidine-3(2H)-one.
D. J. Brown et al., Aust. J. Chem., 1978, 31, 2505, discloses 1,2,4-triazolo[4,3-c]pyrimidines which are substituted at the 3-position by hydrogen or an alkyl substituent, and on the pyrimidine ring by hydrogen and/or alkyl substituents.
D. J. Brown et al., Aust. J. Chem., 1979, 32, 1585, discloses 1,2,4-triazolo[4,3-c]pyrimidines which are substituted at the 3-position by hydrogen or an alkyl substituent, and on the pyrimidine ring at the 5-position by a halogen, hydrazino, methylthio or methyl substituent, and at the 7-position by a methyl substituent. This paper also describes the compound 6-hydrazinyl-4-methyl-2-methylthiopyrimidine.
U.S. Pat. No. 4,269,980 discloses 5-, 7- and 8-(optionally substituted-phenyl)-1,2,4-triazolo[4,3-c]pyrimidines. These compounds may be substituted at the 3-position by hydrogen or an alkyl substituent and are anxiolytic agents. This patent also describes, as intermediates, 6-hydrazinylpyrimidines which contain an optionally-substituted phenyl group in the 2, 4 or 5-position.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to 1,2,4-triazolo[4,3-c]pyrimidines which are bronchodilators. The invention also relates to a method for inducing bronchodilation in a mammal using a 1,2,4-triazolo[4,3-c]pyrimidine of the invention, and to pharmaceutical compositions comprising an effective amount of a 1,2,4-triazolo[4,3-c]pyrimidine of the invention and a pharmaceutically acceptable carrier. The invention also relates to synthetic intermediates useful for preparing certain of the 1,2,4-triazolo[4,3-c]pyrimidines of the invention.
More specifically, the present invention relates to compounds of the formula I ##STR1## wherein R 3 is hydrogen or lower alkyl; R 5 is hydrogen, lower alkyl, lower alkylthio or benzylthio; R 7 is hydrogen, lower alkyl, halogen, phenyl, N-(lower alkyl)amino, N,N-di(lower alkyl)amino, lower alkylthio or benzylthio; and R 8 is hydrogen, lower alkyl, halogen or phenyl; with the provisos that at least one of R 5 and R 7 is lower alkylthio or benzylthio, or R 7 is N-(lower alkyl)amino or N,N-di(lower alkyl)amino; when R 5 is lower alkylthio, R 7 is halogen, phenyl or lower alkylthio, or R 8 is halogen or phenyl, or R 7 is halogen, phenyl, or lower alkylthio and R 8 is halogen or phenyl; and when R 7 is phenyl, R 5 is benzylthio or lower alkylthio; and pharmaceutically acceptable acid-addition salts of the compounds of Formula I.
The present invention also relates to compounds of the Formula II: ##STR2## wherein R 10 is hydrogen, lower alkyl, lower alkylthio or benzylthio; R 12 is hydrogen, lower alkyl, halogen, phenyl, N-(lower alkyl)amino, N,N-di(lower alkyl)amino, lower alkylthio or benzylthio; and R 13 is hydrogen, lower alkyl, halogen or phenyl; with the provisos that at least one of R 10 and R 12 is lower alkylthio or benzylthio, or R 12 is N-(lower alkyl)amino or N,N-di(lower alkyl)amino; when R 10 is lower alkylthio, R 12 is lower alkylthio or phenyl, or R 13 is chloro, fluoro or phenyl, or R 12 is lower alkylthio or phenyl and R 13 is chloro, fluoro or phenyl; and when R 12 is phenyl, R 10 is benzylthio or lower alkylthio.
"Lower alkyl" as used in the instant specification and claims designates straight or branched-chain alkyl groups containing one to four carbon atoms. Preferred lower alkyl groups are methyl, ethyl and n-propyl.
"Halogen" as used in the instant specification and claims designates fluoro, chloro and bromo.
Presently preferred compounds of Formula I are those wherein R 5 is alkylthio and R 7 or R 8 is halogen. Another preferred subclass of compounds is that wherein R 7 is N-lower alkylamino or N,N-di(lower alkyl)amino.
Presently preferred compounds of Formula II are those wherein R 10 is hydrogen, lower alkyl or benzylthio; R 12 is lower alkyl, phenyl, N-(lower alkyl)amino, N,N-di(lower alkyl)amino or lower alkythio; and R 13 is hydrogen, lower alkyl, halogen or phenyl. Another preferred subclass of compounds of Formula II is that wherein R 10 is lower alkylthio and R 12 is phenyl. Still another preferred subclass of compounds are those wherein R 10 and R 12 are lower alkylthio and R 13 is hydrogen.
Specific examples of preferred compounds of Formula I which are active at concentrations of 10 μg per ml or lower in protecting against histamine-induced contraction of isolated guinea pig tracheal tissue are: 5-methylthio-7-chloro-1,2,4-triazolo[4,3-c]pyrimidine; 8-chloro-3-ethyl-5-methylthio-1,2,4-triazolo[4,3-c] pyrimidine; and 3-ethyl-8-fluoro-5-methylthio-1,2,4-triazolo[4,3-c]pyrimidine. This assay is discussed in greater detail below.
The bronchodilator activity of the compounds of Formula I was assessed by the measurement of effects on isolated tracheal spirals. This is a well-known and long established in vitro test method. The bronchodilator activity was determined as follows: Female guinea pigs were sacrificed, and each trachea removed and cut into a spiral strip. This strip was mounted in a constant temperature (37° C.) muscle bath having a volume of approximately 15 ml. The bathing medium was Krebs-Henseleit solution. Movement of the tracheal strip was measured by means of an isometric transducer connected to an electric recorder. The bath was aerated with a mixture of 95% carbon dioxide and 5% oxygen. Contractions were induced in the strips by the addition of a suitable amount of histamine, acetylcholine or barium chloride. The amount of a given compound of Formula I (measured in μg/ml) required to provide greater than 75% relaxation of drug-induced contraction is considered an effective concentration. For comparison, a well known standard bronchodilator, aminophylline, requires concentrations of 50 μg/ml versus histamine, 100 μg/ml versus acetylcholine and 10 μg/ml versus barium chloride to provide greater than 75% relaxation.
Some of the compounds of Formula I were also found to have activity as mucolytics in an in vitro test for mucus production in which rats are orally dosed with compound prior to sacrifice, and the trachea is isolated and incubated with radiolabelled glucosamine. The effect of compounds of Formula I on the incorporation of glucosamine into extracellular mucus is determined. An active compound reduces incorporation of glucosamine.
The compounds of Formula I may be administered to mammals in order to obtain bronchodilation. The compounds may be administered orally, parenterally or by inhalation. Preferably, the compounds are administered parenterally. The usual effective human dose will be 0.1 to 50 mg/kg of body weight.
Acid-addition salts of compounds of Formula I are generally prepared by reaction of a compound of Formula I with an equimolar amount of a relatively strong acid, preferably an inorganic acid such as hydrochloric, sulfuric or phosphoric acid, in a polar solvent. Isolation of the salt is facilitated by the addition of a solvent in which the salt is insoluble, an example of such a solvent being diethyl ether.
The compounds of Formula I wherein R 3 , R 5 , R 7 and R 8 as defined above may be prepared via the following Reaction Scheme I wherein each "Alk" is independently lower alkyl. ##STR3##
In Reaction Scheme I, a compound of Formula III is reacted with an orthoester of Formula IIIA to provide a compound of Formula I. Orthoesters of Formula IIIA are well known and readily available. Examples of suitable orthoesters of Formula IIIA include trimethyl orthoformate, triethyl orthoformate, triethyl orthoacetate, triethyl orthopropionate trimethyl orthobutyrate, trimethyl orthiosobutyrate and the like. Since the orthoesters of Formula IIIA are liquids, it is convenien to mix the intermediates of Formula III with an excess of orthoester and heat the mixture at reflux until reaction is complete. Good yields of the desired compounds of Formula I are isolated by conventional methods. When R 5 is hydrogen, it is necessary to monitor the reaction as it proceeds, or rearrangement to the 1,5-c isomer may occur. Monitoring is conducted by conventional methods such as thin-layer chromatography or nuclear magnetic resonance analysis. The reaction is readily halted by cooling. The structural assignments are made based on infrared and nuclear magnetic spectral analyses. The products are generally white crystalline solids.
In many cases, the intermediates of Formula III are novel compounds, the novel intermediates being those of the more specific Formula II above.
The compounds of Formula III wherein R 3 , R 5 and R 8 are as defined above and R 7 is hydrogen, lower alkyl, halogen, phenyl, lower alkylthio or benzylthio may be prepared as follows in Reaction Scheme II. ##STR4##
In Reaction Scheme II, a substituted 4-chloropyrimidine of Formula IV is reacted with hydrazine hydrate to provide an intermediate of Formula V which may then be reacted via Reaction Scheme I to provide certain compounds of Formula I. Compounds of Formula IV are known or may be prepared from known starting materials using conventional methods. The reaction of Reaction Scheme II is generally carried out by adding two equivalents of hydrazine hydrate to a solution of the compound of Formula IV. The solvent employed is generally a lower alkanol. The reaction is facile and is generally carried out at moderate temperatures, for example, from -20° C. to the reflux temperature of the reaction solvent. The solid product is separated by conventional methods such as filtration, extraction or chromotography, and then is available for use in Reaction Scheme I.
The compounds of Formula III wherein R 3 , R 5 and R 8 are as defined above and R 7 is N-(lower alkyl)amino or N,N-di(lower alkyl)amino may be prepared as follows in Reaction Scheme III wherein "Alk" is lower alkyl and R 15 is hydrogen or lower alkyl. ##STR5##
In Reaction Scheme III, a 4-chloro-6-pyrimidine of Formula VI is reacted with a primary or secondary lower alkyl amine of Formula VIA to provide an intermediate of Formula VII. Compounds of Formula VI are known or may be prepared from known starting materials using conventional methods. Generally, the compound of Formulas VI and amine of Formula VIA are heated together in the absence of solvent, or optionally (and preferably) in the presence of a solvent which does not participate in the reaction such as water. Two equivalents of the amine are preferably used. Alternatively, one equivalent of the amine may be replaced by an inorganic base to neutralize the hydrogen chloride, but lower yields are generally obtained. The reaction mixture is heated at a temperature up to or at the reflux temperature. A temperature is chosen which provides an adequate reaction rate. God yields of the desired products are isolated by conventional methods such as filtration, extraction or chromatography. The novel intermediates of Formula VII are solids whose structural assignments are confirmed by infrared and nuclear magnetic resonance spectral analyses. The intermediates of Formula III may then be employed in Reaction Scheme I to prepare certain compounds of Formula I.
The compounds of Formula III wherein R 3 , R 5 and R 7 are as defined above and R 7 is lower alkylthio may be prepared as follows in Reaction Scheme IV wherein "Alk" is lower alkyl and "M" is an alkali metal. ##STR6##
In Reaction Scheme IV, a 6-chloro-4-hydrazinopyrimidine of Formula VIII is reacted with an alkali metal alkylthiolate of Formula VIIIA to provide a 6-(alkylthio)-pyrimidylhydrazine of Formula IX. Compounds of Formula VIII are known or may be prepared from known starting materials using conventional methods. The reaction of Reaction Scheme IV is generally carried out in a suitable solvent such as an alcohol. Suitable alkali metal alkylthiolates include sodium methyl mercaptide, potassium methyl mercaptide, sodium ethyl mercaptide and the like. The reaction is generally promoted by heating the mixture, for example, at the reflux temperature of the reaction mixture.
The following examples are provided to illustrate the methods used in the invention. They are not intended to limit the invention.
EXAMPLE 1
Preparation of 7-Chloro-5-methylthio-1,2,4-triazolo[4,3-c]pyrimidine
A mixture of 7.0 g (0.037 mole) of 4-chloro-6-hydrazino-2-methylthiopyrimidine and 100 ml of triethyl orthoformate was heated at reflux for 48 hours. Cooling provided a precipitate which was isolated by filtration, and then recystallized from an ethanol-hepane mixture, with treatment with decolorizing charcoal. The product was red crystals of 7-chloro-5-methylthio-1,2,4-triazolo[4,3-c]pyrimidine, m.p. 164°-165° C. Analysis: Calculated for C 6 H 5 N 4 ClS: %C, 35.9; %H, 2.5; %N, 27.9; Found: %C, 36.0; %H, 2,5; %N, 28.5.
EXAMPLES 2-18
Using the method of Example 1, and starting with the indicated pyrimidine of Formula III, the indicated compounds of Formula I were prepared (Table I). The structures were confirmed by elemental, infrared and nuclear magnetic resonance spectral analyses.
TABLE I__________________________________________________________________________ Product of Formula IEx. (m.p. in °C.);No. Pyrimidine of Formula III Orthoester Recrystallization Solvent__________________________________________________________________________ 2 2-benzylthio-4-hydrazino-6- triethyl 5-benzylthio-3-ethyl-7-n-propyl- n-propylpyrimidine orthopropionate 1,2,4-triazolo[4,3-c]pyrimidine (70-72); hexanes 3 2-benzylthio-4-hydrazino-6- triethyl 5-benzylthio-7-n-propyl-1,2,4- n-propylpyrimidine orthoformate triazolo[4,3-c]pyrimidine (74-75); hexanes 4 2-benzylthio-4-hydrazino-6- triethyl 5-benzylthio-3-methyl-7-n- n-propylpyrimidine orthoacetate propyl-1,2,4-triazolo[4,3-c]- pyrimidine (137-139); cyclohexane 5 6-(N,N--diethylamino)-4- trimethyl 7-(N,N--diethylamino)-5-methyl- hydrazino-2-methyl- orthoformate 1,2,4-triazolo[4,3-c]pyrimidine pyrimidine (133-135); benzene/hexanes 6 5-bromo-4-hydrazino-2- triethyl 8-bromo-3-ethyl-5-methylthio- methylthiopyrimidine orthopropionate 1,2,4-triazolo[4,3-c]pyrimidine (162-165); benzene/hexanes 7 5-bromo-4-hydrazino-2- triethyl 8-bromo-3-methyl-5-methylthio- methylthiopyrimidine orthoacetate 1,2,4-triazolo[4,3-c]pyrimidine (220-222); ethanol 8 5-bromo-4-hydrazino-2- triethyl 8-bromo-5-methylthio-1,2,4- methylthiopyrimidine orthoformate triazolo[4,3-c]pyrimidine (166-168); ethyl acetate/hexanes 9 5-chloro-4-hydrazino-2- triethyl 8-chloro-3-ethyl-5-methylthio- methylthiopyrimidine orthopropionate 1,2,4-triazolo[4,3-c]pyrimidine (167-169); ethyl acetate10 2,6-bis(methylthio)-4- triethyl 5,7-bis(methylthio)-1,2,4- hydrazinopyrimidine orthoformate triazolo[4,3-c]pyrimidine (179-181); ethanol/hexanes11 6-chloro-4-hydrazino-2- triethyl 7-chloro-5-methylthio-8-phenyl- methylthio-5-phenylpyrimidine orthoformate 1,2,4-triazolo[4,3-c]pyrimidine (170-171); benzene/hexanes12 6-chloro-4-hydrazino-2- triethyl 7-chloro-3-methyl-5-methylthio- methylthio-5-phenylpyrimidine orthoacetate 8-phenyl-1,2,4-triazolo[4,3-c]- pyrimidine (169-172); cyclohexane13 6-chloro-4-hydrazino-2- triethyl 7-chloro-3-ethyl-5-methylthio- methylthio-5-phenylpyrimidine orthopropionate 8-phenyl-1,2,4-triazolo[4,3-c]- pyrimidine (156-158); benzene/hexanes14 5-fluoro-4-hydrazino-2- triethyl 8-fluoro-3-methyl-5-methyl- methylthiopyrimidine orthoacetate thio-1,2,4-triazolo[4,3-c]- pyrimidine (234-236); ethanol15 5-fluoro-4-hydrazino-2- triethyl 8-fluoro-3-ethyl-5-methylthio- methylthiopyrimidine orthopropionate 1,2,4-triazolo[4,3-c]pyrimidine (139-141); benzene/hexanes16 5-fluoro-4-hydrazino-2- triethyl 8-fluoro-5-methylthio-1,2,4- methylthiopyrimidine orthoformate triazolo[4,3-c]pyrimidine (140-142); none17 5-chloro-4-hydrazino-2- triethyl 8-chloro-3-methyl-5-methylthio- methylthiopyrimidine orthoacetate 1,2,4-triazolo[4,3-c]pyrimidine (228-229); glyme/hexanes18 5-chloro-4-hydrazino-2- triethyl 8-chloro-5-methylthio-1,2,4- methylthiopyrimidine orthoformate triazolo[4,3-c]pyrimidine (155-157); ethanol/hexanes__________________________________________________________________________
EXAMPLE 19
Preparation of 5-Ethylthio-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine
A mixture of 5.0 g (0.020 mole) of 2-ethylthio-4-hydrazino-6-phenylpyrimidine and 50 ml of triethyl orthoformate was heated at its reflux temperature for about 65 hours, and was then allowed to cool to about 20° C. The mixture was poured into ice, and the precipitated product was collected by filtration, and washed with hexanes and air dried. Recrystallization from a 50/50 mixture of cyclohexane and ethyl acetate provided yellowish crystals of 5-ethylthio-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine, m.p. 168°-170° C. Analsyis: Calculated for C 13 H 12 N 4 S: %C, 60.9; %H, 4.7; %N, 21.9; Found: %C, 61.1; %H, 4.6; %N, 22.3.
To a solution of 3.6 g of 5-ethylthio-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine in 100 ml of hot ethanol was added 1.4 g of concentrated sulfuric acid. The mixture was cooled, an equal volume of diethyl ether was added and the precipitate was collected by filtration. The precipitate was recrystallized from a mixture of methanol and diethyl ether to provide 5-ethylthio-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine dihydrogen sulfate hydrate, m.p. 213°-214° C. Analysis: Calculated for C 13 H 12 N 4 S.H 2 SO 4 2/3 H 2 O: %C, 50.4; %H, 4.1; %N, 13.1; Found: %C, 50.4; %H, 4.4; %N, 13.1
EXAMPLE 20
Preparation of 5-Ethylthio-3-methyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine
Using the method of Example 19, 2-ethylthio-4-hydrazino-6-phenylpyrimidine was reacted with triethyl orthoacetate to provide 5-ethylthio-3-methyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine which was recrystallized from a 50/50 mixture of ethyl acetate/cyclohexanes to provide white crystals of 5-ethylthio-3-methyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine, m.p. 219.5°-220° C. Analysis: Calculated for C 14 H 14 N 4 S: %C, 62.2; %H, 5.2; %N, 20.7; Found: %C, 62.2; %H, 5.1; %N, 21.1.
Using the method of Example 19, the above free base was converted to the recrystallized dihydrogen sulfate salt, m.p. 210°-212° C. Analysis: Calculated for C 14 H 14 N 4 S.H 2 SO 4 :%C, 45.6; %H, 4.4; %N, 15.2; Found: %C, 45.5; %H, 4.4; %N, 15.4.
EXAMPLE 21
Preparation of 5-Benzylthio-7-phenyl-1,2,4-triazolo[4,3-]pyrimidine
Using the method of Example 19, 2-benzylthio-4-hydrazino-6-phenylpyrimidine was reacted with triethyl orthoformate, and the reaction product was isolated as the dihydrogen sulfate salt. Recrystallization from a methanol/diethyl ether mixture provided 5-benzylthio-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine dihydrogen sulfate hydrate, m.p. 183°-185° C. Calculated for C 18 H 14 N 4 S.H 2 SO 4 .2/3 H 2 O: %C, 50.4; %H, 4.1; %N, 13.1; Found: %C, 50.3; %H, 4,4; %N, 13.1.
EXAMPLE 22
Preparation of 5-Benzylthio-3-methyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine
Using the method of Example 19, 2-benzylthio-4-hydrazino-6-phenylpyrimidine was reacted with triethyl orthoacetate, and the reaction product was isolated as the dihydrogen sulfate salt. Recrystallization from a methanol/diethyl ether mixture provided 5-benzylthio-3-methyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine dihydrogen sulfate hydrate, m.p. 195°-196° C. Analysis: Calculated for C 19 H 16 N 4 S.H 2 SO 4 .1/2 H 2 O: %C, 51.9; %H, 4.3; %N, 12.7; Found: %C, 51.6; %H, 4.3; %N, 13.0.
EXAMPLE 23
Preparation of 5-Benzylthio-3-ethyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine
Using the method of Example 19, 2-benzylthio-4-hydrazino-6-phenylpyrimidine was reacted with triethyl orthopropionate, and the reaction product was isolated as 5-benzylthio-3-ethyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine dihydrogen sulfate, m.p. 184°-185° C. Analysis: Calculated for C 20 H 18 N 4 S: %C, 54.0; %H, 4.5; %N, 12.6; Found: %C, 54.1; %H, 4.7; %N, 12.7.
EXAMPLE 24
Preparation of 3,5-Dimethyl-7-methylthio-1,2,4-triazolo[4,3-c]pyrimidine
A mixture of 2.5 g (0.015 mole) of 4-hydrazino-2-methyl-6-methythiopyrimidine and 50 ml of triethyl orthoacetate was heated at its reflux temperature for five days, and was then cooled. The solid was separated by filtration and recrystallized with treatment with decolorizing charcoal from first an ethyl acetate-hexane mixture, and then a benzene-hexane mixture to provide 3,5-dimethyl-7-methythio-1,2,4-triazolo[4,3-c]pyrimidine, m.p. 201°-203° C. Calculated for C 8 H 10 N 4 S: %C, 49.5; %H, 5.2; %N, 28.8; Found: %C, 49.6; %H, 5.2; % N, 28.9.
EXAMPLES 25-26
Using the method of Example 24 and starting with the indicated pyrimidines of Formula III, the following compounds of Formula I were prepared (Table II).
TABLE II__________________________________________________________________________Ex. Product of Formula INo. Pyrimidine of Formula III Orthoester (m.p. in °C.)__________________________________________________________________________25 4-hydrazino-2-methyl-6- triethyl 5-methyl-7-methylthio-1,2,4- methylthiopyrimidine orthoformate triazolo[4,3-c]pyrimidine (202-204)26 4-hydrazino-2-methyl-6- triethyl 3-ethyl-5-methyl-7-methylthio-1,2,4- methylthiopyrimidine orthopropionate triazolo[4,3-c]pyrimidine (190-192)__________________________________________________________________________
EXAMPLE 27
To a cold (ice bath) stirred solution of 25 g (0.09 mole) of 4,6-dichloro-2-methylthio-5-phenylpyrimidine in 250 ml of methanol was added slowly 10 g (0.2 mole) of hydrazine hydrate. After one hour the mixture was allowed to warm to about 20° C., and was then stirred at 20° C. for about 16 hours. The precipitate was separated by filtration to provide 4-chloro-6-hydrazino-2-methylthio-5-phenylpyrimidine. Recrystallization twice from hexanes/cyclohexane provided white crystals, m.p. 134°-135° C. Analysis: Calculated for C 11 H 11 ClN 4 S: %C, 49.5; %H, 4.15; % N, 21.0; Found: %C, 49.4; %H, 4.0; %N, 20.9.
EXAMPLES 28-31
Using the method of Example 27 and starting with the indicated 4-chloropyrimidine, the following intermediates of Formula III were prepared (Table III).
TABLE III______________________________________Ex. 4-Chloropyrimidine Intermediate ofNo. Intermediate Formula III (m.p. in °C.)______________________________________28 4-chloro-5-fluoro-2- 5-fluoro-4-hydrazino-2-methyl-methylthiopyrimidine thiopyrimidine (not taken)29 4,5-dichloro-2- 5-chloro-4-hydrazino-2-methyl-methylthiopyrimidine thiopyrimidine (not taken)30 2-benzylthio-4-chloro-6- 2-benzylthio-4-hydrazino-6-phenylpyrimidine phenylpyrimidine (140-142)31 4-chloro-2-ethylthio-6- 2-ethylthio-4-hydrazino-6-phenyl-phenylpyrimidine pyrimidine (110-112)______________________________________
EXAMPLE 32
A mixture of 41 g (0.28 mole) of 4-chloro-6-hydrazinopyrimidine and 90 g (0.3 mole) of sodium methylthiolate in 500 ml of methanol was heated at its reflux temperature for 15 hours. The mixture was then cooled to about 20° C., and the resulting solid was separated by filtration and the filtrate evaporated. The residue and the precipitate were combined and stirred in 500 ml of water. The product was separated by filtration, washed with more water and dried. The product was 4-hydrazino-6-methylthiopyrimidine, m.p. 156°-159° C. The structural assignment was confirmed by nuclear magnetic resonance and infrared spectral analyses.
EXAMPLES 33-34
Using the method of Example 32, the following intermediates of Formula III were prepared from the indicated known 4-chloro-6-hydrazinopyrimidines (Table IV).
TABLE IV______________________________________Ex. 4-Chloro-6- Intermediate ofNo. hydrazinopyrimidine Formula III (m.p. in °C.)______________________________________33 4-chloro-6-hydrazino-2- 2,4-bis(methylthio)-6-hydrazino-methylthiopyrimidine pyrimidine (120-125)34 4-chloro-6-hydrazino-2- 4-hydrazino-2-methyl-6-methyl-methylpyrimidine thiopyrimidine (155-157)______________________________________
EXAMPLE 35
To a suspension of 3.00 g (18.9 mmole) of 4-chloro-6-hydrazino-2-methylpyrimidine in 50 ml of water was added 3.00 g (41.2 mmole) of N,N-diethylamine, and the resulting mixture was then heated at reflux for about 20 hours. The mixture was basified with ten percent aqueous sodium hydroxide solution and extracted with five 40 ml portions of chloroform. The combined extracts were washed with three 50 ml portions of saturated sodium chloride solution, and were then dried over magnesium sulfate and evaporated. The residue was triturated with diethyl ether and cooled. The precipitate was separated by filtration and recrystallized with treatment with decolorizing charcoal from a benzene/hexanes (6/15) mixture to provide an off-white solid which was chiefly 4-(N,N-diethylamino)-6-hydrazino-2-methylpyrimidine, m.p. 95°-103° C. Nuclear magnetic resonance spectral analysis showed about 15% starting material present.
EXAMPLE 36
Preparation of 2-Benzylthio-4-hydrazino-6-n-propylpyrimidine
Part A Preparation of 2-Benzylthio-4-hydroxy-6-n-propylpyrimidine
A mixture of 51.1 g (0.3 mole) of 4-hydroxy-6-n-propylpyrimidine-2-thiol, 51.3 g (0.3 mole) of benzyl bromide, 100 ml of dioxane and 500 ml of 1N aqueous sodium hydroxide solution was heated at 80° C. for four hours. After cooling, the solid was collected by filtration to provide white crystals of 2-benzylthio-4-hydroxy-6-n-propylpyrimidine, m.p. 122°-126° C.
Part B Preparation of 2-Benzylthio-4-chloro-6-n-propylpyrimidine
A mixture of 72 g (0.28 mole) of 2-benzylthio-4-hydroxy-6-n-propylpyrimidine (from Part A) and 100 ml of phosphorus oxychloride was heated at reflux for three hours, and was then allowed to cool to 20° C. After evaporating in vacuo the residue was poured into ice water with vigorous stirring. The mixture was extracted with three 75 ml portions of diethyl ether, and the extracts were dried over magnesium sulfate and evaporated to provide a yellow oil residue of 2-benzylthio-4-chloro-6-n-propylpyrimidine.
Part C Preparation of 2-Benzylthio-4-hydrazino-6-n-propylpyrimidine
A mixture of 40 g (0.014 mole) of 2-benzylthio-4-chloro-6-n-propylpyrimidine (from Part B) and 15 g (0.3 mole) of hydrazine hydrate in 300 ml of ethanol was heated at reflux for 2 hours, cooled and evaporated. Water was added to the residue. The white solid was collected by filtration and dried to provide 2-benzylthio-4-hydrazino-6-n-propylpyrimidine. The structural assignment was confirmed by infrared and nuclear magnetic resonance spectral analyses. | Substituted triazolo[4,3-c]pyrimidines which are bronchodilators. The pharmacological use of these compounds, pharmaceutical compositions containing these compounds, and synthetic intermediates for the preparation of these compounds are also described. | 2 |
[0001] This Patent Application filed for the invention by Lydia A. Kinnard, of Antioch, Tenn. 37013-5623 of a “Infant Stomach Band To Protect From Injury.”
[0002] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no obligation to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
[0003] All patents and publications described or discussed herein are hereby incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
[0004] This present invention relates generally to a band used to protect infants from injury. More specifically, the present invention relates to a band designed to prevent hernias in infants and help prevent protruding belly buttons in infants. The current invention can have especially useful application for infants having colic.
[0005] There have been numerous advancements in medical science, including medical science directed at the improvement of the health and well being of infants. These advancements have been focused on both proactive and reactive treatments. However, infant healthcare can be especially difficult since infants do not have the capacity to specifically communicate to the caregivers the health issues that they are experiencing. For example, obviously an infant cannot specifically articulate to a doctor nurse, or caregiver the specific areas experiencing pain or any specific description of the type of sensation of the pain. This difficulty leads to a lot of crying by the infant and reactive care by the caregiver. This reactive care is normally in the form of food, additional clothing, diaper changes, and the like. This care to infant is normally guesswork on the caregiver's part. As such, the infant can experience stress and manifest that stress in long emotional outbursts of crying. These outbursts can lead to stress-related symptoms within the infant, such as a hernia.
[0006] Much of the prior art attempts to address hernias in infants have revolved around externally applied medicine for hernias. For example, U.S. Pat. No. 6,921,547 is directed at such a device. This device specifically calls for a dosage unit in powder form contained within a fabric pouch applied to the navel of a baby suffering from a hernia. As such, this patent is reactive to the already medically-diagnosed issue, mainly a hernia and the infant still experiences the pain and requires time to heal in order to recover from the physical ailment.
[0007] What is needed then is a preventive device and/or medical treatment in which to prevent hernias in infants and can prevent the protruding belly buttons in infants. This needed device can preferably be disposable or non-disposable and varying adjustments used to correspond to the various sizes of infants.
BRIEF SUMMARY OF THE INVENTION
[0008] Disclosed herein is an infant stomach band to protect the infant from injury. This band has particular usefulness in helping to prevent hernias in infants and preventing protruding belly buttons in infants. The band can have a especially useful applications for babies having colic.
[0009] The band preferably includes an expanded middle section that substantially corresponds to the lower abdomen of an infant. A first and second armature extends from the expanded middle section wherein opposite ends of the armature include attachment devices used to attach the free end of the armatures together around the infant.
[0010] The infant band can also include a secondary attachment on the expanded section that interfaces with the diaper of the infant to the band in place. The attachment devices at the distal ends of the bands can be various attachment devices known, such as Velcro, adhesives, and the like.
[0011] It is therefore a general object of the present invention to provide an infant stomach band.
[0012] Another object of the present invention is to provide an infant stomach band to protect an infant from injury, such as a strain-related injury.
[0013] Another object of the present invention is to provide an infant stomach band to protect an infant from a hernia.
[0014] Another object of the present invention is to provide an infant stomach band to prevent the infant from developing a protruding belly button.
[0015] Another object of the present invention is to provide an adjustable band used to secure the lower abdomen of an infant.
[0016] Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon reading of the following disclosure when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of an infant band made in accordance with the current disclosure.
[0018] FIG. 2 is a cross-section taken along line A-A of FIG. 1 .
[0019] FIG. 3 is a perspective view of an alternative embodiment of an infant band made in accordance with the current disclosure.
[0020] FIG. 4 is a black perspective view of the infant band shown in FIG. 3
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring generally to FIG. 1-4 , an infant band is shown and generally designated by the numeral 10 . The band 10 includes an expanded section 12 and first and second armatures 14 and 16 extending from the expanded section 12 . The expanded section 12 includes a width that is preferably wider than the armatures 14 and 16 . The expanded section can include an attachment device 20 positioned thereon to facilitate the attachment of the band to the clothing and/or diaper of an infant. This attachment device 20 can be materials known in the art to secure two items together, such as Velcro, adhesives, and the like. Preferably the attachment 20 is designed such that it can be repeatedly used to secure the band 10 to the clothing and/or diapers of the infant.
[0022] The first and second armatures 14 and 16 can include a securing device 22 used to remove ably attach the distal ends 15 and 17 of the armatures 14 and 16 , respectively. The securing device 22 can be a single piece, or multiple pieces, known in the art to secure two items together. Examples are Velcro adhesives. And the like. Preferably the securing device 22 can be multiple times to secure the distal ends 15 and 17 of the armatures 14 and 16 respectively. This secure device 22 facilitates a proper fit of the band 10 around the waist of an infant.
[0023] Preferably the band 10 compromises a cloth type material 24 covering an elastic material 26 . The elastic material 26 can provide the resistance needed to help prevent the hernia and/or bulging belly buttons in infants. The cloth material 24 helps facilitate the attachment between the band 10 and the diaper and/or clothing of the infant while providing protection to the infant from the elastic material 26 . The cloth material 24 is preferably stretchable and breathable while being a soft and comfortable material. Additional padding can be included beneath the cloth material 24 and can be preferably positioned between a cloth material and elastic material 26 to provide comfort to the infant.
[0024] Ideally the band can be used once the umbilical cord has fallen off of an infant and that area is fully healed. This can take approximately 2-3 weeks for proper healing to allow use of the band.
[0025] In a preferred embodiment the band 10 compromises disposable materials substantially similar to the diaper materials used for infants' diapers. The band 10 can include absorbent qualities as present in those in diapers while maintaining the predetermined geometrical shape to help prevent the hernia injuries and bulging belly button areas in infants.
[0026] In an alternate preferred embodiment the band 10 can be composed of washable materials such that any soiling of the band 10 can be cleaned in normal washing. This alternate embodiment will be composed of stronger attachment devices and securing 20 and 22 respectively to withstand the cleaning and washing of the band 10 . The elastic material 26 could be removable from within the cloth material 24 to facilitate this washing and cleaning.
[0027] Still yet another alternative embodiment of the band 10 compromises a cloth material that is composed of substantially all cotton. This cotton is designed in such a way to provide the required pressure on the abdomen of the infant to help prevent the hernia injury. As such, in this embodiment the substantially all cotton band would be washable without the need of removal of any additional materials from within or special washing techniques.
[0028] The band 10 can have various types of designs to enhance the aesthetic appearance of the band. For example, these designs can be gender based as well as specific activity based. These designs would normally be positioned external to the band 10 and can be positioned on the cloth material 24 to facilitate the aesthetic look of the band 10 .
[0029] Thus, although there have been described particular embodiments of the present invention of a new and useful Infant Stomach Band To Protect From Injury, it is not intended that such references be construed as limitations upon the scope of this invention except as set fort in the following claims. | Disclosed herein is an infant stomach band to protect the infant from injury. This band has particular usefulness in helping to prevent hernias in infants and preventing protruding belly buttons in infants. The band can have a especially useful applications for babies having colic. | 0 |
All publications and patent applications mentioned in this specification are incorporated herein, in their entirety, by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
FIELD OF THE INVENTION
The present invention relates, generally, to management of Bowden-type cables in articulating instruments or snake-like robots. More particularly, the present invention relates to managing Bowden-type cables to reduce or eliminate catastrophic permanent lateral plastic deformation (also referred to herein as kinking or herniation) of these cables in articulating instruments or snake-like robots.
BACKGROUND OF THE INVENTION
The forms of robots vary widely, but all robots share the features of a mechanical, movable structure under some form of control. The mechanical structure or kinematic chain (analogous to the human skeleton) of a robot is formed from several links (analogous to human bones), actuators (analogous to human muscle) and joints permitting one or more degrees of freedom of motion of the links. A continuum or multi-segment robot is a continuously curving device, like an elephant trunk for example. An example of a continuum or multi-segment robot is a snake-like endoscopic device, like that under investigation by NeoGuide Systems, Inc., and described in U.S. Pat. Nos. 6,468,203; 6,610,007; 6,800,056; 6,974,411; 6,984,203; 6,837,846; and 6,858,005. Another example of a snake-like robotic device is shown and described in U.S. Patent Publication US2005/0059960 to Simaan, et al.
Snake-like robots often use Bowden cables to transfer forces from an actuator to particular sections or segments of the snake-like robot to effect articulation of that section or segment. Multiple, simultaneous articulations of the snake-like robot require the Bowden cables to go through multiple tortuous paths. One challenge faced by the practitioner is that Bowden cables can herniate under overloading conditions and axial loads placed upon them as a result of articulation. Various embodiments of the present invention address this issue.
SUMMARY OF THE INVENTION
An embodiment of the present invention is a system for managing the transmission of force to articulate an elongate device or snake-like robot. The system, of this embodiment, has an elongate body comprising a plurality of articulatable segments. The system includes a plurality of coil pipes, where each coil pipe is fixed at its proximal end relative to an actuator, at its distal end relative to a proximal portion of one of the plurality of articulatable segments, and where the coil pipes extend along each segment in a spiral pattern. A plurality of tensioning members is provided, where the tensioning members are housed in the plurality of coil pipes. The proximal end of each tensioning member is coupled to the actuator, and the distal end extends out the distal end of the coil pipe and is coupled to the articulatable segment to which the distal end of the coil pipe is fixed. The coil pipe/tensioning member combination works like a Bowden cable. The tensioning of one or more of the tensioning members causes articulation of the articulatable segment. In an alternative embodiment of the present invention, the articulatable segments are constructed from at least two links and preferably at least four links jointed together. Preferably, the links are control rings, such as and without limitation vertebrae, and the joints are hinges between the vertebrae. In an alternative embodiment the spiral pattern comprises an approximate integral number of approximately full turns along each of the plurality of articulatable segments, and preferably approximately one full turn.
In an alternative system for managing the transmission of force in an articulating device, the system comprises an elongate body have a plurality of articulatable segments. Bowden cables are coupled at a proximal end to an actuator and at a distal end to a proximal portion of one of the articulatable segments. Actuation of one or more of the Bowden cables causes the articulation of one or more of the segments to which the Bowden cables are coupled. The Bowden cables extend along each segment in a spiral pattern.
In another embodiment coil pipes are constructed from approximately round wire, D-shaped wire or are centerless ground. A D-shaped coil pipe that is less susceptible to herniation or axial overloading, in accordance with an embodiment of the present invention, can comprise D-shaped wire coiled, around a mandrel, for example, into a pipe shape. The wire used to make this embodiment of coil pipe has a cross-section having two approximately parallel approximately flat sides, a convex side and a concave side approximately parallel to said convex side. Preferably, the concave side of the wire of a first coil approximately nests with the convex side of the wire in a second adjacent coil, and the approximately parallel flat sides form an interior and an exterior of the coil pipe. The convex and concave sides can have an approximately curved shape, such as and without limitation a portion of a circle. Alternatively, the convex and concave sides can have an angular shape, such as and without limitation a V-shape. Alternatively, the wire can have a square or rectangular cross-section. A coil pipe can also comprise approximately circular cross-section wire coiled, around a mandrel for example, into a pipe shape. In a further embodiment of the present invention the pipe shape is ground or otherwise has material removed to form approximately parallel exterior flat sides, thereby forming a centerless ground coil pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the detailed description below that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings.
In the drawings:
FIG. 1 depicts an endoscope in accordance with an embodiment of the present invention;
FIG. 2 depicts an embodiment of a steerable distal portion or a controllable segment of an endoscope in accordance with the present invention;
FIG. 3 depicts a schematic diagram of either a steerable distal portion or a controllable segment of an endoscope in accordance with the present invention;
FIG. 4 depicts embodiments of vertebrae-type control rings in accordance with an embodiment of the present invention;
FIG. 5 depicts a schematic of how to arrange coil pipes and tendons relative to actuators and an articulatable segment or tip;
FIG. 6 provides a graphic for explaining static radial frictional forces between tendons and coil pipes in an embodiment of the present invention where the coil pipes are not spiraled;
FIG. 7 depicts a schematic of advancing an endoscope in a colon in accordance with an embodiment of the present invention;
FIG. 8 depicts a schematic of an undesirable bell-shape bend of a coil tube;
FIG. 9 depicts an embodiment of a coil pipe made with circular cross-section wire and a herniation of the coil pipe;
FIG. 10 depicts a centerless ground coil pipe in accordance with an embodiment of the present invention;
FIG. 11 depicts a coil pipe made with “D-shaped” wire in accordance with an embodiment of the present invention, and various embodiments of how to make “D-shaped” wire;
FIG. 12 depicts an illustration of coil pipe spiraled along a segment in accordance with an embodiment of the present invention;
FIG. 13 provides a graphic for explaining static radial frictional forces between tendons and coil pipes in an embodiment of the present invention where the coil pipes are spiraled;
FIG. 14 provides a schematic for describing one alternative for spiraling of coil pipes along a segment in accordance with an embodiment of the present invention; and
FIG. 15 depicts an alternative embodiment of a steerable distal portion or a controllable segment.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts endoscope 10 , a colonoscope in particular, in accordance with an embodiment of the present invention. Endoscope 10 has elongate body 12 with steerable distal portion 14 , automatically controlled proximal portion 16 , and flexible and passively manipulated proximal portion 18 . The skilled artisan will appreciate that automatically controlled proximal portion 16 may also be flexible and passively manipulated, although it is preferred to provide automatically controlled proximal portion 16 . The skilled artisan will also appreciate that elongate body 12 can have only steerable distal portion 14 and automatically controlled portion 16 . Fiber optic imaging bundle 20 and illumination fiber(s) 22 may extend through elongate body 12 to steerable distal portion 14 , or video camera 24 (e.g., CCD or CMOS camera) may be positioned at the distal end of steerable distal portion 14 , as known by the skilled artisan. As the skilled artisan appreciates, a user views live or delayed video feed from video camera 24 via a video cable (e.g., wire or optical fiber, not shown) or through wireless transmission of the video signal. Typically, as will be appreciated by the skilled artisan, endoscope 10 will also include one or more access lumens, working channels, light channels, air and water channels, vacuum channels, and a host of other well known complements useful for both medical and industrial endoscopy. These channels and other amenities are shown generically as 26 , because such channels and amenities are well known and appreciated by the skilled artisan.
Preferably, automatically controlled proximal portion 16 comprises a plurality of segments 28 , which are controlled via computer and/or electronic controller 30 . Such an automatically controlled endoscope is described in further detail in commonly assigned U.S. patent application Ser. No. 10/229,577 (now U.S. Pat. No. 6,858,005) and Ser. No. 11/750,988, both previously incorporated herein by reference. Preferably, the distal end of a tendon (more thoroughly described below) is mechanically connected to a each segment 28 or steerable distal portion 14 , with the proximal end of the tendon mechanically connected to actuators to articulate segments 28 or steerable distal portion 14 , which is more fully described below and in U.S. patent application Ser. No. 10/229,577 (now U.S. Pat. No. 6,858,005) and Ser. No. 11/750,988, both previously incorporated herein by reference. The actuators driving the tendons may include a variety of different types of mechanisms capable of applying a force to a tendon, e.g., electromechanical motors, pneumatic and hydraulic cylinders, pneumatic and hydraulic motors, solenoids, shape memory alloy wires, electronic rotary actuators or other devices or methods as known in the art. If shape memory alloy wires are used, they are preferably configured into several wire bundles attached at a proximal end of each of the tendons within the controller. Segment articulation may be accomplished by applying energy, e.g., electrical current, electrical voltage, heat, etc., to each of the bundles to actuate a linear motion in the wire bundles which in turn actuate the tendon movement. The linear translation of the actuators within the controller may be configured to move over a relatively short distance to accomplish effective articulation depending upon the desired degree of segment movement and articulation. In addition, the skilled artisan will also appreciate that knobs attached to rack and pinion gearing can be used to actuate the tendons attached to steerable distal portion 14 . An axial motion transducer 32 (also called a depth referencing device or datum) may be provided for measuring the axial motion, i.e., the depth change, of elongate body 12 as it is advanced and withdrawn. As elongate body 12 of endoscope 10 slides through axial motion transducer 32 , it indicates the axial position of the elongate body 12 with respect to a fixed point of reference. Axial motion transducer 32 is more fully described in U.S. patent application Ser. No. 10/229,577, previously incorporated herein by reference.
In the embodiment depicted in FIG. 1 , handle 34 is connected to illumination source 36 by illumination cable 38 that is connected to or continuous with illumination fibers 22 . Handle 34 is connected to electronic controller 30 by way of controller cable 40 . Steering controller 42 (e.g., a joy stick) is connected to electronic controller 30 by way of second cable 44 or directly to handle 34 . Electronic controller 30 controls the movement of the segmented automatically controlled proximal portion 16 , which is described more thoroughly below and in U.S. patent application Ser. No. 11/750,988, previously incorporated herein by reference.
Referring to FIG. 2 , steerable distal portion 14 and segments 28 of automatically controlled proximal portion 16 are preferably constructed from a plurality of links 46 . Five links 46 are shown in this example for the sake of clarity, although the skilled artisan will recognize that any number of links may be used, the ultimate number being primarily defined by the purpose for which segments 28 or steerable distal portion 14 will be used. Each link 46 connects one joint (e.g., 47 ) to an adjacent joint (e.g., 47 ). Each link 46 , in this embodiment, can move with two degrees of freedom relative to an adjacent link.
Referring now to FIG. 3A-C a schematic diagram of either steerable distal portion 14 or segments 28 is provided for discussion purposes and to explain a preferred system and method for articulating steerable distal portion 14 or segments 28 . The skilled artisan will recognize that the system and method for articulation is the same for both steerable distal portion 14 and segments 28 of automatically controlled proximal portion 16 . Therefore, the system and method for articulation will be described referring only to segments 28 , with the recognition that the description also applies equally to steerable distal portion 14 . It is noted that details relating to links 46 , joints 47 and the interconnections of the links have been eliminated from this figure for the sake of clarity.
FIG. 3A shows a three-dimensional view of segment 28 in its substantially straight configuration. The most distal link 46 A and most proximal link 46 B are depicted as circles. Bowden cables extend down the length of elongate body 12 (not shown in FIGS. 3A-C ) and comprise coil pipes 48 and tendons 50 . The proximal end of the Bowden-type cable is coupled to an actuator (not shown) and the distal end is coupled to the segment for which it controls articulation. Coil pipes 48 house tendons 50 (i.e. a Bowden-type cable) along the length of elongate body 12 (not shown in FIGS. 3A-C ) and coil pipes 48 are fixed at the proximal end of segment 28 . Tendons 50 extend out of coil pipes 48 at the proximal end of segment 28 along the length of segment 28 , and are mechanically attached to the distal portion of segment 28 . It will be appreciated that the distal end of tendons 50 need only be attached to the segment being articulated by that tendon 50 at a location required to transfer the actuated force to that segment to effect articulation; the distal portion of the segment is provided by way of explanation and example, and not by way of limitation. In the variation depicted in FIG. 3A-C four tendons 50 are depicted to articulate segment 28 , but more or fewer may be used. The coil pipe/tendon combination, or Bowden cables, can be used to apply force to articulate segments 28 and can be actuated remotely to deliver forces as desired to articulate segments 28 . In this manner, actuation of one or more tendons 50 causes segment 28 to articulate. In the embodiment depicted, links 46 have joints 47 alternating by 90 degrees (see FIGS. 2 and 4 ). Thus, an assembly of multiple links 46 is able to move in many directions, limited only by the number of actuated joints. As will be appreciated by the skilled artisan, tendons 50 can be made from a variety of materials, which is primarily dictated by the purpose for which the endoscope will be used. Without limitation tendons 50 can be made from stainless steel, titanium, nitinol, ultra high molecular weight polyethylene, the latter of which is preferred, or any other suitable material known to the skilled artisan.
In the variation depicted in FIG. 3A-C , four tendons 50 are used to articulate segment 28 , although more or fewer tendons could be used, as will be appreciated by the skilled artisan. Four tendons can reliably articulate segment 28 in many directions. Tendons 50 are attached at the most distal link 46 A, for the purposes of this discussion but not by way of limitation, close to the edge spaced equally apart at 12, 3, 6, and 9 O'clock.
FIG. 3B-C show segment 28 articulated by independently pulling or slacking each of the four tendons 50 . For example, referring to FIG. 3B , pulling on tendon 50 at the 12 O'clock position and easing tension on tendon 50 at the 6 O'clock position causes steerable distal portion 28 to articulate in the positive y-direction with respect to the z-y-x reference frame 52 . It is noted that the most distal z-y-x coordinate frame 52 distal rotates with respect to the z-y-x reference frame 52 and that β is the degree of overall articulation of segment 28 . In this situation β is only along the positive y-axis, up, because only tendon 50 at the 12 O'clock position was pulled while easing tension or giving slack to tendon 50 at 6 O'clock. The tendons 50 at 3- and 9 O'clock were left substantially static in this example, and, thus, had approximately no or little affect on articulation of segment 28 . The reverse situation (not depicted), pulling on tendon 50 at the 6 O'clock position and slacking or easing the tension on tendon 50 at the 12 O'clock position results in articulation of segment 28 in the negative y-direction, or down. Referring to FIG. 3C the same logic applies to articulate segment 28 in the positive x-direction (right) or a negative x-direction (left, not shown). Segment 28 can be articulated in any direction by applying varying tensions to the tendons off axis, e.g., applying tension to the tendons at 12 O'clock and 3 O'clock results in an articulation up and to the left.
Referring now to FIG. 4 , links 46 may be control rings to provide the structure needed to construct steerable distal portion 14 and segments 28 . FIG. 4A shows a first variation of a vertebra-type control ring 54 that forms segments 28 or steerable distal portion 14 . FIG. 4B shows an end view of a single vertebra-type control ring 54 of this first variation. In this embodiment each vertebra-type control ring 54 define a central aperture 56 that collectively form an internal lumen of the device, which internal lumen is used to house the various access lumens, working channels, light channels, air and water channels, vacuum channels, and a host of other well known complements useful for both medical and industrial endoscopy. Vertebrae-type control rings 54 have two pairs of joints or hinges 58 A and 58 B; the first pair 58 A projecting perpendicularly from a first face of the vertebra and a second pair 58 B, located 90 degrees around the circumference from the first pair, projecting perpendicularly away from the face of the vertebra on a second face of the vertebra opposite to the first face. Hinges 58 A and 58 B are tab-shaped, however other shapes may also be used.
Referring briefly to FIG. 5 , tension applied to tendon 50 by actuator 60 is isolated to a particular segment 28 by use of coil pipe 48 housing tendon 50 , as previously described. Referring back again to FIG. 4A , vertebra-type control ring 54 is shown with four holes 60 through the edge of vertebra-type control ring 54 that may act as, e.g., attachment sites for tendon 50 , as a throughway for tendon 50 in other vertebrae-type control rings 54 (links) of that particular segment 28 and/or attachment sites for coil pipes 48 when vertebra-type control ring 54 is the most proximal link in segment 28 . The skilled artisan will appreciate that the number of tendons 50 used to articulate each segment 28 or tip 14 determines the number of holes 60 provided for passage of tendons 50 .
The outer edge of vertebra-type control ring 54 in the variation depicted in FIG. 4A-B may be scalloped to provide bypass spaces 62 for tendons 50 and coil pipes 48 that control more distal segments 28 or tip 14 , and that bypass vertebra-type control ring 54 and the present segment 28 . These coil pipe bypass spaces 62 , in this variation of the vertebrae-type control ring 54 , preferably conform to the outer diameter of coil pipes 48 . The number of coil pipe bypass spaces 62 vary depending on the number of tendons, and, therefore, the number of coil pipes needed to articulate all the segments 28 and steerable distal portion 14 . It will be appreciated that not all vertebrae-type control rings 54 of a particular segment 28 need to have coil pipe bypass spaces 62 . As described further below, intermediate vertebra-type control rings 54 ′ ( FIG. 4C ) between segments need not have coil pipe bypass spaces 62 , rather the coil pipes can simply pass through the lumen formed by central aperture 56 ′. In this alternative, the lumen formed by central aperture 56 ′ house the various access lumens, working channels, light channels, air and water channels, vacuum channels, as described above, as well as coil pipe/tendon combinations that do not control that particular segment.
FIG. 4D-E show another variation of vertebra-type control ring 64 in sectional and perspective views. In FIG. 4D-E , tendons 50 and coil pipes 48 that bypass a segment may be contained within body 66 ( FIG. 4D ) of vertebra-type control ring 64 in an alternative coil pipe bypassing space or quadrant 68 , rather than the scallops 62 along the outer edge of vertebra-type control ring 54 as previously described. Quadrants 68 are the preferred way to handle coil pipes 48 that must by-pass a segment. Vertebra-type control ring 64 of FIG. 4D-4E show four coil pipe bypassing spaces/quadrants 68 , but more or fewer may be used. It will be appreciated that cross bar 57 can pivot at hinge points 59 in one embodiment or may fixed relative to body 66 . Other aspects of this variation of vertebra-type control ring are similar to that described above and are, accordingly, called out with the same reference number. It is noted that tie-off rods 104 can be used to tie off the distal ends of tendons 50 in this embodiment.
The skilled artisan will appreciate that coil pipes 48 by-passing a vertebrae via quadrants 68 will define an approximately cylindrical coil pipe containment space roughly defined by the outer diameter of vertebrae-type control ring 64 . This space is loosely defined by the grouped coil pipes as they pass through and between the vertebrae. As described more thoroughly below, it is possible and preferred to have intermediate vertebra-type control rings without coil pipe bypassing spaces, as shown in vertebra-type control ring 54 ′ ( FIG. 4C ) or 65 ( FIG. 4F ). In either construction, central aperture 56 or 56 ′ of the control rings collectively forms a lumen (not shown) through which channels and cables necessary or desired for the endoscope function pass, as well as coil pipes and tendons by-passing that particular segment. Preferably, more proximal segments will have larger diameter vertebrae in order to provide larger quadrants 68 or central aperture 56 or 56 ′ to accommodate a larger number of coil pipes 48 that must reach the more distal segments 28 and tip 14 . The more distal segments 28 and steerable distal portion 14 can be constructed with vertebrae-type control rings 64 or 65 having a smaller diameter, thereby making the distal portions of elongate body 12 have a smaller diameter. While this is preferred, the skilled artisan will recognize that any diameter vertebrae may be used limited only by the need to accommodate the coil pipes and tendons necessary to articulate segments 28 and steerable distal portion 14 of the endoscope.
Referring again to FIG. 5 , coil pipes 48 are fixed at their distal and proximal ends between actuators 60 and the proximal end of segment 28 under control by those actuators. FIG. 5 shows only one segment 28 (which, as discussed, could also be steerable distal portion 14 ), and, for clarity, the other parts of a complete endoscope have been omitted from FIG. 5 . When tendons 50 are placed under tension, the force is transferred across the length of segment 28 ; coil pipes 48 provide the opposite force at the proximal end of the segment being articulated in order to cause the articulation. This force is, primarily, a compression force or axial loading transferred along the length of the coil pipe where it is fixed between the actuator and the proximal end of the segment being articulated. A preferred embodiment of the present invention utilizes one actuator per tendon, and utilizes four tendons per segment, as described above, although only one actuator 60 is depicted for clarity. Details relating to actuator 60 and connecting actuator 60 to tendons 50 are described in U.S. patent application Ser. No. 10/988,212, previously incorporated by reference.
The skilled artisan will appreciate that articulation of multiple segments 28 along the length of elongate body 12 will require that many coil pipes 50 extend down the length of elongate body 12 and through coil pipe by-passing spaces, with the number decreasing by four coil pipes (in this example) at the proximal end of each segment. Thus, a 17 segmented elongate body (16 segments 28 and 1 tip 14 ) requires 68 coil pipes going into the proximal end of elongate body 12 , which decreases by four coil pipes for each distally adjacent segment 28 (assuming one uses four tendon/coil pipes combinations per segment as in the present example). It also requires the actuation or tensioning of 68 tendons, with four tendons terminating at the distal end of each segment. This requires 68 actuators in this preferred embodiment, one actuator per tendon 50 .
The skilled artisan will also appreciate that there is not a one to one correspondence between the force applied by actuators 60 at the proximal end of tendons 50 and the force realized at the distal end of tendons 50 to articulate segment 28 . When elongate body 12 is in its substantially straight configuration, friction between tendons 50 and coil pipes 48 results in frictional losses along the length of the coil pipe while applying tension to articulate a segment or the tip. Articulation of segments 28 and steerable distal portion 14 results in further losses and inefficiencies for many reasons. For example, and without limitation, when elongate body 12 articulates (for example at the Sigmoid colon during a colonoscopy procedure), coil pipes 48 must move longitudinally along elongate body 12 to either “gain” or “lose” length depending whether coil pipes 48 are on the inner or outer portion of the bend created by the articulation. As described above, an embodiment of the present invention provides quadrants 68 or coil pipe by-passing spaces 62 that permit the passage of coil pipes 48 along elongate body 12 until they reach the proximal portion of the segment they control. The “gain” or “loss” of coil pipe length requires coil pipes 48 to slide up and down elongate body 12 and within quadrants 68 or coil pipe by-passing spaces 62 creating further frictional losses by virtue of friction between the coil pipes and/or between the coil pipes and the vertebra. There is also the additional friction created between a coil pipe and a tendon by virtue of the bend.
Frictional losses caused by the coil pipe/tendon bending (by virtue of a segment bending) reduce the working force available to articulate segments. The frictional loss is dependent on the material coefficient of friction and the accumulated bend (total tortuosity) of the coil pipe/tendon as elongate body 12 moves through a tortuous path. Total tortuosity is the amount of accumulated bend along the length of a coil pipe, which is closely approximated by the amount of accumulated bend along the length of that portion of elongate body 12 through which the coil pipe travels. For example an S-bend through the Sigmoid colon would contribute approximately 2×90° or 180° to the total tortuosity. As a segment bends coil pipes/tendons within that segment will also bend. The tendon tension applies a normal load towards the center of curvature of the coil pipe, as depicted in FIG. 6 that graphically depicts a coil pipe going through a 180 bend around a column.
Referring to FIG. 6 , the static friction for coil pipes extending down the length of elongate body 12 can be represented by the following balanced equations, where θ is the total tortuosity. Delta_F is constant with a given load L on either tendon. Note there are at least three sources of friction: (1) friction between the tendons and the coil pipe; (2) friction between the coil pipes and the ring structures; and (3) friction between the individual coil pipes.
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Having found Delta_F, the general normal cable loading is F N =Delta_F*θ=L*θ. The static radial friction is, therefore, F r (θ)=F N *μ=Delta_F*θ*μ=L*θ*μ (μ is coefficient of friction). Note that this equation has been solved for an ideal, hypothetical situation where the coil pipe is bent around a hypothetical column and static equal load is place at either end of the tendon going through the coil pipe. The same analysis applies for the static friction between a coil pipe and ring structures of a segment, where L is the given external load on the coil pipe. The solution is the same, but will have different loads (L) and different coefficients of friction (μ). This is a reasonable model to assess the static frictional loads for a coil pipe going through a segment comprised of vertebra-type ring structures having a total tortuosity of θ. Therefore, the static friction force for 180 degrees of accumulated tortuosity (two ninety degree bends or an S-bend, for example) is F r (π)=π*L*μ. The calculation for brake free forces and dynamic resistance loads is more complicated but can also be solved with an exponentially decaying resistance load.
Additionally, but related, elongate body 12 may enter more than one tortuous bend simultaneously. Referring to FIG. 7A-B , this occurs when, for example and without limitation, performing a colonoscopy with an embodiment of the present invention elongate body 12 must move through a highly tortuous path. Electronic controller 30 , in a preferred embodiment, controls the articulation of each segment 28 to take the shape of adjacent segments or tip as elongate body 12 is advanced through a tortuous path, such as the colon. Referring to FIG. 7A , a user articulates steerable distal portion 14 to select a desired path, through the Sigmoid colon S for example (an approximate S-bend or 180 degrees of total tortuosity), and then advances the endoscope through the anus A. Electronic controller 30 knows the shape of segments 28 and steerable distal portion 14 prior to the advancement of elongate body 12 into the colon, as described more thoroughly in U.S. patent application Ser. No. 11/019,963, previously incorporated herein by reference. Electronic controller 30 causes adjacent segments to adopt the shape of the segment or steerable distal portion immediately preceding it. Therefore, upon advancing elongate body 12 through the colon C, electronic motion controller 30 will maintain the approximate tortuous S-shape of the Sigmoid colon S in elongate body 12 by automatically controlling segments 28 to adopt the approximate shape of the immediately preceding segment. This follow-the-leader technique is further described in U.S. patent application Ser. No. 11/019,963, previously incorporated herein by reference. As described above, coil pipes 48 need to slide along elongate body 12 to accommodate the “gain” or “loss” of coil pipe length resulting from the articulation of elongate body 12 . Recall from the equation above that the frictional force is proportional to both total tortuosity and the material coefficient of friction. There are two coefficients of friction of interest, one for the tendon against the internal lumen of the coil pipe, and the other for the coil pipe against the vertebra-type ring structures.
Referring to FIG. 7B , when steerable distal portion 14 of elongate body 12 enters into a second tortuous bend, at the splenic flexure F 1 of the colon for example, coil pipes 48 need to accommodate the “gain” or “loss” of coil pipe length for both the new bend in the splenic flexure F 1 and for the first S-bend at the Sigmoid colon S. As the user advances elongate body 12 into the transverse colon T electronic controller 30 continues to maintain the bends at the splenic flexure F 1 and the Sigmoid colon S. However, coil pipes 48 need to slide the entire length of elongate body 12 (as described above), including through the first tortuous proximal bend in the Sigmoid colon S, and the second tortuous more distal bend in the splenic flexure F 1 to accommodate for the “loss” and “gain” of coil pipe length.
It was found that coil pipes 48 did not have the ability to slide along the length of elongate body 12 when in such a tortuous state. Without wishing to be bound by any particular theory, the inventors believe that the frictional forces between the coil pipes and the vertebra-type ring structures bind the coil pipes and they are unable to slide along the length of elongate body 12 . Referring to FIG. 8 , catastrophically the coil pipe exits the coil pipe containment boundary (discussed previously) in a severe bell-curve type shape 70 , or adopts severe bends (not shown) within the coil pipe containment boundary. This bell-curve bend 70 and/or other severe bends in coil pipes 48 dramatically increases friction between coil pipes 48 and tendons 50 , and also stiffens the segments requiring greater forces to achieve the desired articulation than would otherwise be required without the bell-curve or other severe bends in the coil pipes. As the segments having bell-shape curve 70 and/or other severe bends in coil pipe 48 straighten, the excess coil pipe length is no longer required to accommodate the bend in that particular segment of elongate body 12 . Therefore, coil pipe 48 moves back into the coil pipe containment area and/or the other severe bends begin to straighten as the bend in segment 28 begins to straighten, but in doing so coil pipe 48 frequently herniates. The skilled artisan will appreciate that herniation of the coil pipe can be caused by a variety of mechanisms. Moreover, the skilled artisan will appreciate that bell-curve shape 70 or other severe bends can occur anywhere along the length of elongate body 12 , and the location of such bends is not limited to the bending segments. A herniation, as will be described more fully below, is a permanent or plastic lateral deformation of the coil pipe. The primary cause of a herniation is believed by the inventors (without wishing to be bound by any particular theory) to be the result of the coil pipes binding (i.e. inability to slide or significantly reduced ability to slide) along the length of elongate body 12 .
Referring to FIG. 9 , coil pipes 48 are typically made of circular cross-section high tensile strength wire 72 wound in a tight coil to form a hollow pipe-like structure. The larger the tensile strength the more difficult it will be to make the material plastically deform. In a preferred embodiment high tensile 302 , 303 or 304 VT SST was specified with a tensile strength greater than about 40,000 PSI. In a herniated coil pipe 48 H ( FIG. 9B ) at least one of the coils 74 is permanently, laterally displaced, thereby significantly decreasing the effective diameter through which tendon 50 may pass. This results in a concomitant catastrophic increase in the frictional losses caused by friction between the coil pipe and the tendon passing therethrough. This lateral displacement also significantly reduces column strength of the coil pipe, thereby significantly reducing the ability to articulate a segment. In addition to significantly reducing the amount of force delivered by tendon 50 to articulate the segment or tip, the additional friction will prematurely wear out tendon 50 .
Without wishing to be bound by any particular theory, the inventors believe that the coil pipes rubbing on the vertebrae (or other ring structure) as the coil pipes re-enter the coil pipe containment area or otherwise straighten cause lateral forces on the coil pipes, which cause the coil pipes to resist axial movement or bind leading them to herniate. The inventors further hypothesize, again without wishing to be bound by any particular theory, that the ridges 76 ( FIG. 9A ) of the coiled wire 72 bump along the vertebrae or ring structure as the coil pipes re-enter the coil pipe containment area or otherwise straighten creating additional forces on the coil pipe structure. This is further exacerbated, again without being bound by any particular theory, by the bell-shaped curve or other severe bends separating the coils similar to the bending of a spring, thereby making the ridges more pronounced.
FIG. 10 depicts an embodiment of centerless ground coil pipe 78 in accordance with an embodiment of the present invention. As described above coil pipes 48 slide along the length of elongate body 12 as segments 28 articulate along a tortuous path. Adding lubricity between coil pipes 48 is, therefore, desired. However, using a lubricant, such as oil or other substance, is not highly desired because, at a minimum, the lubricant wears out making more frequent service of the endoscope necessary. Centerless ground coil pipe 78 is essentially the same as coil pipe 48 described above, but approximately half the diameter of coil wire 72 (shown in shadow) on either side of centerless ground coil pipe 78 is ground away or removed to create the centerless ground coil pipe 78 . The opposing flat sides 80 provide increased lubricity between coil pipes as they slide up and down elongate body 12 , and also provide increased lubricity as “excess” coil pipe length slides back into the coil pipe containment area or otherwise straightens. The skilled artisan will appreciate that any appropriate lubricant may also be used in combination with the centerless ground coil pipes, although this is not preferred. The inventors found that this solution did not sufficiently resolve the binding and ultimate herniation of the coil pipes. The inventors hypothesize that the design is sound, but the less preferred outcome of the solution resulted from the difficulty in reliably manufacturing centerless ground coil pipes with substantially opposing substantially flat sides.
In accordance with an alternative embodiment of the present invention FIG. 11A depicts D-shaped coil pipe 82 made from D-shaped wire 84 . In this embodiment convex portion 90 of D-shaped wire approximately nests in concave portion 92 of D-shaped wire ( FIG. 11A ). D-shaped wire 84 can be manufactured in a number of ways as will be appreciated by the skilled artisan. In one embodiment, referring to FIG. 11B , round wire 72 is rolled by first roller 91 or “Turkshead die” into an approximate oval shape 93 and the wire is rotated approximately 90 degrees and fed into second roller 94 or “Turkshead die.” Second roller 94 creates the concave shape 92 and convex shape 90 at opposite ends of the parallel substantially flat sides 86 created by first roller 91 . Alternatively, D-shaped wire can be formed by extrusion or by pulling a fully annealed or soft wire through one or more dies as shown in FIG. 11C . First, wire 72 is pulled through die 92 to obtain an approximately oval shaped wire 96 . Oval shaped wire 96 is then pulled through die 98 to provide the concave shape 92 and convex shape 90 at opposite ends of the parallel substantially flat sides 86 . The wire is then hardened to hold a set shape as in a coil pipe. The skilled artisan will appreciate that dies 95 and 98 can be a single die and that orientation of the die or rotation of the wire is a matter of manufacturing choice. This would also be true with the orientation of first and second rollers discussed above.
Manufacture of D-shaped coil pipe 82 with D-shaped wire is similar to the manufacture of coil pipe made with circular wire. Referring to FIG. 11D , the main difference is that D-shaped wire 84 needs to be oriented with one of the flat sides 86 against mandrel 88 . Preferably, the convex portion 90 of the “D” approximately nests into the concave portion 92 of the “D” as the D-shaped wire is wound onto the mandrel to form the coil pipe.
Nesting convex portion 90 into concave portion 92 provides for a higher surface area contact between wires of each coil than a coil pipe manufactured with circular cross section wire, particularly when the coil pipe is under compressive stresses. Additionally, the sides of convex portion 90 and concave portion 92 provide resistance against herniation upon application of lateral forces. Like the centerless ground coil pipe 78 , D-shaped coil pipe 82 also provides increased lubricity by virtue of substantially flat portions 86 of D-shaped coil pipe 82 . D-shaped coil pipe 82 worked better than centerless ground coil pipe 78 in preventing herniations, and is therefore more preferred over centerless ground coil pipe 78 . Additionally, the manufacturability of D-shaped coil pipe 82 is more consistent than that of the centerless ground coil pipe 78 , which adds to the preference of D-shaped coil pipe 82 . Furthermore, orienting coil pipe 48 to grind off or flatten the sides to achieve centerless ground coil pipe 78 can prove challenging, as discussed above. The skilled artisan will appreciate that shapes of wire other than D-shaped may be used in accordance with the present invention. For example the concave and convex portion of D-shaped coil pipe 82 may have any geometrical shape that can nest together. These may include, without limitation, V-shaped coil pipe 94 ( FIG. 11E ). Furthermore, an alternative embodiment, though not preferred, could be square or rectangular cross-section wire oriented to have flat sides against each other, as shown in FIG. 11F , which also will provide resistance against herniation upon application of lateral forces. Additionally, a benefit of using Bowden-type cables made from coil pipes is that they are flexible even when under compressive load. D-shaped coil pipes also remain very flexible under high compressive loads.
FIG. 12 depicts a preferred alternative embodiment for managing the coil pipes that reduces or eliminates the herniation problem by reducing or eliminating the need for the coil pipes to slide along the entire length of elongate body 12 . As described above, coil pipe 48 must slide up or down the entire length of elongate body 12 to accommodate a bend in a segment. Referring to FIG. 12 , spiraling coil pipes 48 along elongate body 12 and segments 28 significantly reduces and effectively eliminates the herniation problems identified above. Without wishing to be bound by any particular theory, the inventors hypothesize that the spiraled coil pipe localizes the movement or slacking of the coil pipes to an area at or close to the segment undergoing articulation. Therefore, again without wishing to be bound by any particular theory, when a segment articulates the spiraled coil pipe moves within or near a segment locally, thereby reducing or eliminating the need for the coil pipe to slide up or down the entire length of the elongate body. An analogy, again without wishing to be bound by any particular theory, would be a rope or cable made of spiraled strands bending over a pulley; the gain and loss of length of the individual strands in the rope takes place locally at the point of the bend around the pulley, because the strands alternate from the outside to the inside of the bend; the inside strand section gives what the outside strand needs.
The inventors observed that the spiraled coil pipes did not exit the coil pipe containment area in bell shaped curves or exhibit other extreme bends as described above, and they observed little to no herniation of the coil pipes. Spiraling the coil pipes will reduce or prevent herniation with D-Shaped, centerless ground or circular wire coil pipes as well. However, circular wire coil pipes are preferred for ease of manufacturing reasons.
The main benefit with using a spiraled structure identified by the inventors is reduced friction between a coil pipe and vertebra-type ring structures by virtue of the elimination or reduction of sliding of the coil pipes along the elongate body. There is a relatively smaller increase of frictional forces resulting from the increase of overall length of coil pipe through which a tendon must pass, and an increase of overall tortuosity as a result of spiraling the coil pipes along elongate body 12 .
The static friction from a spiral loading differs from that of radial loading described above. Tendon tension, as described for radial loading, applies a normal load toward the center of curvature and results in static radial friction of F r (n)=μ*L*μ for 180 degrees of total tortuosity. Static radial loading for a spiraled coil pipe can be solved and calculated in the same fashion. It is noted that because, as hypothesized by the inventors, spiraling localizes coil pipe movement to a segment undergoing a bend friction for coil pipes sliding against vertebra-type ring structures is reduced or eliminated. Referring to FIG. 13 , cable load L is assumed to be the same at both ends of the spiral. Balanced equations follow, where γ is the spiral angle and θ is, again, total tortuosity, which as noted is increased by virtue of the spiral:
∫
-
π
/
2
π
/
2
Delta_F
*
cos
(
θ
)
ⅆ
θ
=
2
*
L
*
sin
(
γ
)
;
units
of
Delta_F
are
in
force
/
angle
Delta_F
*
[
sin
(
π
/
2
)
-
(
sin
(
-
π
/
2
)
)
]
=
2
*
L
*
sin
(
γ
)
;
Delta_F
*
[
1
-
(
-
1
)
]
=
2
*
L
*
sin
(
γ
)
Delta_F
=
L
*
sin
(
γ
)
Having found Delta_F the general normal cable loading is F N =Delta_F*θ*sin(γ)=L*θ*sin(γ). The static radial friction is, therefore, F r (θ)=F N *μ=Delta_F*θ*sin(γ)*μ=μ*L*θ*sin(γ). Note that this equation has been solved for an ideal, hypothetical situation where the coil pipe is spiraled around a hypothetical column 180° and static equal load is place at either end of the tendon going through the coil pipe. This is a reasonable model to assess the static frictional loads for a coil pipe spiraling through a segment comprised of vertebra-type ring structures. It must be recalled, however, that total tortuosity is now increased as a result of the spiraling.
Total tortuosity is the sum of all angles of bends in a coil pipe from its proximal end assuming the coil pipes are not spiraled along the elongate body. However, as will be appreciated, the spiral angle γ adds to the total tortuosity, but under larger (high degree of) bends of a segment the amount of tortuosity added by for small spiral angles (γ) is approximately the same as that of a non-spiraled embodiment undergoing the same multiple bends, so long as the spiraling is not excessive. Excessive spiraling with large spiral angle γ or wrapping the coil pipe too many times around a segment has a deleterious affect for several reasons. One reason is that the increased number of wraps dramatically increases the length of the coil pipe, thereby increasing the friction between the coil pipe and the tendon. More importantly, the overall tortuosity θ increases to an unacceptable level with the increased number of wraps (which proportionally increases the static friction) and spiral angle, i.e., friction added (F r ≈*L*θ*sin(γ)) increases directly with spiral angle. The inventors reasoned that too much spiraling would result in the detriment of increased friction by virtue of the increase of total tortuosity (θ) out weighing the benefit of reducing or eliminating binding. Numerically the inventors determined that a single 360 degree spiral, or approximately one wrap along each segment is the preferred amount of spiraling. It was determined empirically and numerically that approximately one 360 degree spiral wrap per segment of approximately 10 cm along the elongate body reduced or eliminated the need for the coil pipe to slide between segments to accommodate a bend, thereby reducing or eliminating herniation, and that this benefit far outweighed any increase of friction resulting from the amount of tortuosity added by the spiraled coil pipes. It was also determined numerically that an integral number of spiral wraps was preferred to ensure localization of coil pipe movement during the bending of a segment. The skilled artisan will appreciate the amount of spiraling or wraps used will depend on the system and the purpose for which the system will be used. It will also be appreciated that the spiral angle (γ) need not be constant along the length of a segment.
Referring back to FIG. 4D-F , in an embodiment of the present invention, quadrants 68 of vertebrae type control ring 64 are used to maintain coil pipes 48 spiraled along elongate body 12 . In this embodiment more than one vertebra-type control ring 64 in a segment has quadrants 68 , and the coil pipes are passed through the quadrants to established the preferred approximately one spiral wrap per segment. In another preferred embodiment, referring briefly to FIG. 15A , distal (not shown) and proximal vertebrae-type control rings 64 of each segment have quadrants 68 , and intermediate vertebrae-type control rings 65 do not have quadrants 68 . In this preferred embodiment the quadrants are approximately longitudinally aligned, and coil pipes are passed through the aligned quadrants after spiraling within the intermediate control rings 65 to achieve the preferred approximately one spiral wrap. It will be appreciated that the number of coil pipes passing through the quadrants will be equally divided between the quadrants, although other configurations can be used. The skilled artisan will appreciate that many different configurations and mechanisms may be used to maintain the spiral along the length of elongate body 12 .
Referring to FIG. 14 , coil pipes 48 are routed through quadrants 68 (not shown) in proximal vertebra-type control ring 64 in segment 28 , through vertebra-type control rings 65 without quadrants in that segment, through quadrants 68 (not shown) in distal vertebra-type control ring 64 in that segment. The working channel, fiber optics cable, suction channel, video cable and the like (not shown) are routed through central opening 56 of vertebra-type control rings 64 and through the lumen (along with the coil pipes) created by intermediate vertebra-type control rings 65 without quadrants. The vertebrae 64 with the quadrants are then rotated relative to each other to achieve the amount of desired spiraling of the coil pipes, the rotation being depicted graphically in FIG. 14B . Hinging of the vertebrae will maintain the spiral, as will be appreciated by the skilled artisan. As noted, approximately a full spiral wrap of 2π per segment 28 is preferred, but the skilled artisan will appreciate that the number of wraps will depend on the purpose for which the device will be used. As will also be appreciated, only four coil pipes are depicted with the other details of the segments and endoscope being omitted from FIG. 14 for purposes of clarity. It is noted that the skilled artisan will appreciate many different configurations of vertebra-type control rings with and without quadrants can be used to achieve the desired spiraling.
As noted, at least one vertebra control ring 64 with quadrants 68 is used per segment and preferably two to maintain the preferred spiral structure of the coil pipes by-passing that segment, and that the remaining vertebra-type control rings of that segment do not have quadrants. As discussed above, central opening 56 of vertebra-type control ring 64 provides a location for passing working channels, optical cables and the like through vertebra-type control ring 64 and quadrants 68 provide a separate by-pass space for coil pipes not controlling articulation of that particular segment, and for maintaining the spiral structure of the coil pipes. The remaining control rings 65 of a segment have no by-pass space. Rather, the coil pipes, the working channel, air line, water line, suction line, optical cables and the like all pass through the central lumen created by central opening 56 ′ ( FIG. 4F ) of vertebra-type control rings 65 by aligning vertebra-type control rings 65 , and are not separated by quadrants 68 as in vertebra-type control rings 64 .
Referring again to FIG. 15 , tendons 50 controlling a particular segment are kept separate from the spiraled coil pipes, the working channel, air line, water line etc. by intermediate ring structures 100 attached at the hinge between control rings 65 not having quadrants 68 . These intermediate ring structures 100 ( FIG. 15B ) are situated between vertebra control rings 65 . Four holes 102 are shown in ring structure 100 through which tendons 50 controlling articulation of that segment run. More holes may be used per tendon depending on how force is applied to the segment via the tendon(s), and the total number of holes depends on the number of tendons 50 used to control the segment, tour in this example. In the proximal vertebra-type control ring 64 having quadrants 68 , holes 60 are where coil pipes controlling that segment terminate and are fixed. As described above, tendon 50 extends out of the coil pipe and along the segment through holes 100 and then terminate at the distal end of the segment at tie off rods 104 of the distal vertebra-type control ring 64 . The skilled artisan will recognize that tendon 50 controlling a particular segment need only terminate somewhere within that segment such that force can be effectively transferred to and along that segment to effect articulation.
This preferred embodiment has the advantage of, at least, (1) spiraling the coil pipes along the length of the elongate body, as described above, and (2) providing relatively unconstrained space in vertebra-type control rings 65 without quadrants 68 intermediate to vertebra-type control rings 64 having quadrants 68 , such that coil pipes can move locally and relatively unconstrained to accommodate articulation of that particular segment. The inventors believe, again without wishing to be bound by any particular theory, that this permits the coil pipes to move locally and accommodate the bend in a segment without having to slide the entire length of the elongate body, thereby not binding the coil pipes and the concomitant reduction or elimination of herniations in the coil pipes.
The skilled artisan will appreciate there are many different ring structures and many different ways to achieve the desired spiral structure of coil pipes. For example, and without limitation, the coil pipes could be spirally arranged in scalloped by-pass spaces 62 in the outer edge of vertebra-type control ring 60 ( FIG. 4A-B ), although this is less desirable because it moves the coil pipes further away from the desired longitudinal centerline of elongate body 12 , and these spaces have more friction than when the coil pipes are passed through quadrants 68 or the center 65 of vertebrae. Additionally, the skilled artisan will appreciate that quadrants 68 can exist in more than one vertebra-type control ring 64 within a segment, and that more or fewer than four quadrants can be used. The skilled artisan will appreciate how to orient quadrants on one vertebra relative those on an other vertebra(e) having quadrants within a segment and along the elongate body to achieve the desired spiral arrangement of coil pipes.
The foregoing description, for purposes of explanation, used some specific nomenclature to provide a thorough understanding of the invention. Nevertheless, the foregoing descriptions of the preferred embodiments of the present invention are presented for purposes of illustration and description and are not intended to be exhaustive or to limit the invention to the precise forms disclosed; obvious modification and variation are possible in view of the above teachings. | The present invention relates, generally, to the reduction or elimination of permanent and catastrophic herniations in Bowden cables or coil pipes in articulating devices or snake-like robots. More particularly, the present invention relates managing the coil pipes in a spiral pattern along the articulating device or snake-like robot to reduce or eliminate the necessity of the Bowden cables or coil pipes to slide along the length of the articulating device or snake-like robot. Reduction or elimination of the necessity for the Bowden cables or coil pipes to slide reduces or eliminates catastrophic herniations in articulating devices or snake-like robots undergoing one or more articulations. | 5 |
This application claims the benefit of U.S. Provisional Application No. 60/369,470, filed Apr. 3, 2002, which is incorporated in its entirety as a part hereof for all purposes.
FIELD OF THE INVENTION
This invention relates to a process for hydrogenating nepetalactone, utilizing a metal catalyst that is optionally supported, to yield dihydronepetalactone.
BACKGROUND OF THE INVENTION
Many plant species belonging to the family Labiatae (Lamiaceae) produce essential oils (aromatic oils) which are used as natural sources of insect repellent and fragrant chemicals [Hay, R. K. M. and Svoboda, K. P. Botany, In “Volatile Oil Crops: their biology, chemistry and production”; Hay, R. K. M., Waterman, P. G. (eds.); Longman Group UK Limited (1993)]. Plants of the genus Nepeta (catmints) are included as members of this family, and produce an essential oil which is a minor item of commerce. This oil is very rich in a class of monoterpenoid compounds known as iridoids [Inouye, H. Iridoids. Methods in Plant Biochemistry 7:99-143 (1991)], more specifically the methylcyclopentanoid nepetalactones [Clark, L. J. et al. The Plant Journal, 11:1387-1393 (1997)] and derivatives.
Four stereoisomers of nepetalactone are known to exist in nature, which may be readily obtained from different species within the plant genus Nepeta. These chemicals exert a well-known excitatory effect on cats [Tucker, A. O. and S. S. Tucker. Economic Botany 42: 214-231 (1988)], thus the oil—or more commonly, the dried herbage of this plant termed catnip—is used in cat toys. The leaves and oil of Nepeta spp. do not possess a particularly attractive aroma. The uses of the herbage and oil has therefore been confined to the small market offered by domestic cat toys and accessories. A small proportion of the oil of various Nepeta spp. consists of dihydronepetalactones, which are possibly derived biosynthetically from the more abundant nepetalactones [Regnier, F. E., et al. Phytochemistry 6:1281-1289 (1967); DePooter, H. L., et al. Flavour and Fragrance Journal 3:155-159 (1988); Handjieva, N. V. and S. S. Popov. J. Essential Oil Res. 8:639-643 (1996)].
Iridoid monoterpenoids have long been known to be effective repellents to a variety of insect species [Eisner, T. Science 146:1318-1320 (1964); Eisner, T. Science 148:966-968 (1965); Peterson, C. and J. Coats, Pesticide Outlook 12:154-158 (2001); and Peterson, C. et al. Abstracts of Papers American Chemical Society, (2001) 222 (1-2): AGRO73]. However, studies of the repellency of dihydronepetalactones have been much less conclusive [Cavill, G. W. K., and D. V. Clark. J. Insect Physiol. 13:131-135 (1967); Cavill, G. W. K., et al. Tetrahedron 38:1931-1938 (1982); Jefson, M., et al. J. Chemical Ecology 9:159-180 (1983)]. Recent studies have indicated that dihydronepetalactones may exert a repellent effect on the common insect pests of human society. Thus, a source of dihydronepetalactones (or a precursor) capable of supplying these compounds economically and in quantity may be required to allow commercial application of these molecules as insect repellents.
Additionally, it has been proposed that dihydronepetalactone compounds be used as fragrance materials. In view of these considerations, a source of dihydronepetalactones (or a precursor) capable of supplying these compounds economically and in quantity may also be required to allow commercial application of these molecules as fragrance materials.
Processes for hydrogenating iridoid monoterpene lactones (e.g., isoneonepetalactone, isodehydroiridomyrmecin, and isoactinidialactone) have been reported using platinum oxide (PtO 2 ) catalyst [Sakai, T. et al. Bull. Chem. Soc. Jpn., 53(12): 3683-6 (1980)]. Likewise, neonepetalactone and isoneonepetalactone were hydrogenated with PtO 2 in Et 2 O and with Raney Ni in ethanol [Sakai, T. et al. Koen Yoshishu—Koryo, Terupen oyobi Seiyu Kagaku ni kansuru Toronkai, 23rd (1979), 45-48; Publisher: Chem. Soc. Japan, Tokyo, Japan].
Using similar methodology, processes for producing dihydronepetalactones by hydrogenation of nepetalactone are described in Regnier, R. E. et al. [ Phytochemistry 6:1281-1289 (1967)]. Specifically, nepetalactone was treated with hydrogen and platinum oxide (PtO 2 ) catalyst to yield
53% methyl-2-isopropyl-5-methylcyclopentanecarboxylate, 2.8% α-dihydronepetalactone, and 35% δ-dihydronepetalactone.
When a palladium catalyst supported on strontium carbonate (Pd/SrCO 3 ) was used,
90% α-dihydronepetalactone, 3% methyl-2-isopropyl-5-methylcyclopentanecarboxylate, and a trace of δ-dihydronepetalactone was formed.
Both of these strategies for hydrogenation are limited, however; PtO 2 is an unsupported catalyst which permitted formation of a significant amount of open-ring derivatives, while SrCO 3 is an expensive support.
A need thus remains for an economical, efficient process for the production of dihydronepetalactones. The metals selected for use as catalysts in the process of this invention provide the desired economy and efficiency of production with a high degree of selectivity to the dihydronepetalactone product.
SUMMARY OF THE INVENTION
One embodiment of this invention is a process for the production of a dihydronepetalactone of formula (II) by hydrogenating a nepetalactone of formula (I) according to the following scheme:
in the presence of a catalytic metal that is not nickel, platinum or palladium.
Another embodiment of this invention is a process for the production of a dihydronepetalactone of formula (II) by hydrogenating a nepetalactone of formula (I) according to the following scheme:
in the presence of a catalytic metal selected from one or more members of the group consisting of nickel supported on a catalyst support, elemental platinum, platinum supported on a catalyst support, palladium not supported on a catalyst support, and palladium supported on a catalyst support that is not SrCO 3 .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the chemical structures of the naturally-occurring iridoid (methylcyclopentanoid) nepetalactones.
DETAILED DESCRIPTION OF THE INVENTION
The term “nepetalactone” as used herein refers to the compound having the general structure, as defined by Formula I:
Four stereoisomers of nepetalactone are known to exist in nature, as shown in FIG. 1 .
The term “dihydronepetalactones” or “dihydronepetalactone mixtures” as used herein refers to any mixture of dihydronepetalactone stereoisomers. The molar or mass composition of each of these isomers relative to the whole dihydronepetalactone composition can be variable. Dihydronepetalactones are defined by Formula 2:
wherein 4, 4a, 7 and 7a indicate the four chiral centers of the molecule and the structure encompasses all possible stereoisomers of dihydronepetalactone.
The structures of dihydronepetalactone stereoisomers that may be derived from (7S)-nepetalactones are shown below.
The term “catalyst” as used herein refers to a substance that affects the rate of a chemical reaction (but not the reaction equilibrium) and emerges from the process chemically unchanged.
The term “promoter” as used herein is a compound that is added to enhance the physical or chemical function of a catalyst. A chemical promoter generally augments the activity of a catalyst and may be incorporated into the catalyst during any step in the chemical processing of the catalyst constituent. The chemical promoter generally enhances the physical or chemical function of the catalyst agent, but can also be added to retard undesirable side reactions. A “metal promoter” refers to a metallic compound that is added to enhance the physical or chemical function of a catalyst.
Nepetalactones
Nepetalactone is a known material that can be conveniently obtained in relatively pure form from the essential oils isolated by various means from plants of the genus Nepeta (catmints). Isolation of such oils is well known in the art, and examples of methodology for oil extraction include (but are not limited to) steam distillation, organic solvent extraction, microwave-assisted organic solvent extraction, supercritical fluid extraction, mechanical extraction and enfleurage (initial cold extraction into fats followed by organic solvent extraction).
The essential oils isolated from different Nepeta species are well known to possess different proportions of each naturally-occurring stereoisomer of nepetalactone [Regnier, F. E., et al. Phytochemistry 6:1281-1289 (1967); DePooter, H. L., et al. Flavour and Fragrance Journal 3:155-159 (1988); Handjieva, N. V. and S. S. Popov. J. Essential Oil Res. 8:639-643 (1996)]. Thus, from oil derived from any Nepeta species containing a mixture of nepetalactones, a mixture of dihydronepetalactone stereoisomers will be generated upon hydrogenation. Four chiral centers are present within the methylcyclopentanoid backbone of the nepetalactone at carbons 4, 4a, 7 and 7a as shown below:
Thus it is clear that a total of eight pairs of dihydronepetalactone enantiomers are possible after hydrogenation of these, the naturally occurring stereoisomers described thus far are (7S)-dihydronepetalactones.
Hydrogenation
Hydrogenation of nepetalactone is effected in the presence of a suitable active metal hydrogenation catalyst. Acceptable solvents, catalysts, apparatus, and procedures for hydrogenation in general can be found in Augustine, Heterogeneous Catalysis for the Synthetic Chemist, Marcel Decker, New York, N.Y. (1996).
Many hydrogenation catalysts are effective, including (without limitation) those containing as the principal component iridium, palladium, rhodium, nickel, ruthenium, platinum, rhenium, compounds thereof, combinations thereof, and the supported versions thereof.
The metal catalyst used in the process of this invention may be used as a supported or as an unsupported catalyst. A supported catalyst is one in which the active catalyst agent is deposited on a support material by spraying, soaking or physical mixing, followed by drying, calcination, and if necessary, activation through methods such as reduction or oxidation. Materials frequently used as support are porous solids with high total surface areas (external and internal) which can provide high concentrations of active sites per unit weight of catalyst. The catalyst support may enhance the function of the catalyst agent; and supported catalysts are generally preferred because the active metal catalyst is used more efficiently. A catalyst which is not supported on a catalyst support material is an unsupported catalyst.
The catalyst support can be any solid, inert substance including, but not limited to, oxides such as silica, alumina, titania, calcium carbonate, barium sulfate, and carbons. The catalyst support can be in the form of powder, granules, pellets, or the like. A preferred support material of the present invention is selected from the group consisting of carbon, alumina, silica, silica-alumina, titania, titania-alumina, titania-silica, barium, calcium, compounds thereof and combinations thereof. Suitable supports include carbon, SiO 2 , CaCO 3 , BaSO 4 and Al 2 O 3 . Moreover, supported catalytic metals may have the same supporting material or different supporting materials.
In one embodiment of the instant invention, a more preferred support is carbon. Further preferred supports are those, particularly carbon, that have a surface area greater than 100-200 m 2 /g. Further preferred supports are those, particularly carbon, that have a surface area of at least 300 m 2 /g.
Commercially available carbons which may be used in this invention include those sold under the following trademarks: Bameby & Sutcliffe™, Darco™, Nuchar™, Columbia JXN™, Columbia LCK™, Calgon PCB™, Calgon BPL™, Westvaco™, Norit™ and Barnaby Cheny NB™. The carbon can also be commercially available carbon such as Calsicat C, Sibunit C, or Calgon C (commercially available under the registered trademark Centaur®).
Preferred combinations of catalytic metal and support system include
nickel on carbon, nickel on Al 2 O 3 , nickel on CaCO 3 , nickel on BaSO 4 , nickel on SiO 2 , platinum on carbon, platinum on Al 2 O 3 , platinum on CaCO 3 , platinum on BaSO 4 , platinum on SiO 2 , palladium on carbon, palladium on Al 2 O 3 , palladium on CaCO 3 , palladium on BaSO 4 , palladium on SiO 2 , iridium on carbon, iridium on Al 2 O 3 , iridium on SiO 2 , iridium on CaCO 3 , iridium on BaSO 4 , rhenium on carbon, rhenium on Al 2 O 3 , rhenium on SiO 2 , rhenium on CaCO 3 , rhenium on BaSO 4 , rhodium on carbon, rhodium on Al 2 O 3 , rhodium on SiO 2 , rhodium on CaCO 3 , rhodium on BaSO 4 , ruthenium on carbon, ruthenium on Al 2 O 3 , ruthenium on CaCO 3 , ruthenium on BaSO 4 , and ruthenium on SiO 2 .
As stated above, useful catalytic metals include component iridium, palladium, rhodium, nickel, ruthenium, platinum, rhenium; and useful support materials include carbon, alumina, silica, silica-alumina, titania, titania-alumina, titania-silica, barium, calcium, particularly carbon, SiO 2 , CaCO 3 , BaSO 4 and Al 2 O 3 . A supported catalyst may be made from any combination of the above named metals and support materials. A supported catalyst may also, however, be made from combinations of various metals and/or various support materials selected from subgroup(s) of the foregoing formed by omitting any one or more members from the whole groups as set forth in the lists above. As a result, the supported catalyst may in such instance not only be made from one or more metals and/or support materials selected from subgroup(s) of any size that may be formed from the whole groups as set forth in the lists above, but may also be made in the absence of the members that have been omitted from the whole groups to form the subgroup(s). The subgroup(s) formed by omitting various members from the whole groups in the lists above may, moreover, contain any number of the members of the whole groups such that those members of the whole groups that are excluded to form the subgroup(s) are absent from the subgroup(s). For example, it may be desired in certain instances to run the process in the absence of a catalyst formed from palladium on carbon.
While the weight percent of catalyst on the support is not critical, it will be appreciated that the higher the weight percent of metal, the faster the reaction. A preferred content range of the metal in a supported catalyst is from about 0.1 wt % to about 20 wt % of the whole of the supported catalyst (catalyst weight plus the support weight). A more preferred catalytic metal content range is from about 1 wt % to about 10 wt % by weight of the whole of the supported catalyst. A further preferred catalytic metal content range is from about 3 wt % to about 7 wt % by weight of the whole of the supported catalyst.
Optionally, a metal promoter may be used with the catalytic metal in the method of the present invention. Suitable metal promoters include: 1) those elements from groups 1 and 2 of the periodic table; 2) tin, copper, gold, silver, and combinations thereof; and 3) combinations of group 8 metals of the periodic table in lesser amounts.
Temperature, solvent, catalyst, pressure and mixing rate are all parameters that affect the hydrogenation. The relationships among these parameters may be adjusted to effect the desired conversion, reaction rate, and selectivity in the reaction of the process.
Within the context of the present invention the preferred temperature is from about 25° C. to 250° C., more preferably from about 50° C. to about 150° C., and most preferred from about 50° C. to 100° C. The hydrogen pressure is preferably about 0.1 to about 20 MPa, more preferably about 0.3 to 10 MPa, and most preferably about 0.3 to 4 MPa. The reaction may be performed neat or in the presence of a solvent. Useful solvents include those known in the art of hydrogenation such as hydrocarbons, ethers, and alcohols. Alcohols are most preferred, particularly lower alkanols such as methanol, ethanol, propanol, butanol, and pentanol. Where the reaction is carried out according to the preferred embodiments, selectivites in the range of at least 70% are attainable where selectivites of at least 85% are typical. Selectivity is the weight percent of the converted material that is dihydronepetalactone where the converted material is the portion of the starting material that participates in the hydrogenation reaction.
The process of the present invention may be carried out in batch, sequential batch (i.e. a series of batch reactors) or in continuous mode in any of the equipment customarily employed for continuous processes (see, for example, H. S. Fogler, Elementary Chemical Reaction Engineering, Prentice-Hall, Inc., NJ, USA). The condensate water formed as the product of the reaction is removed by separation methods customarily employed for such separations.
Upon completion of the hydrogenation reaction, the resulting mixture of dihydronepetalactone isomer products may be separated by a conventional method, such as for example, by distillation, by crystallization, or by preparative liquid chromatography to yield each highly purified pair of dihydronepetalactone enantiomers. Chiral chromatography may be employed to separate enantiomers.
EXAMPLES
The present invention is further defined in the following examples. These examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these examples, the artisan can ascertain the essential characteristics of this invention, and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
The following abbreviations are used in the examples:
ESCAT
Series of catalysts provided by
Engelhard Corp., (E. Windsor, CT).
Calsicat Carbon
Catalyst support from Engelhard
Corp.
Sibunit Carbon
Catalyst support from Inst. of
Technical Carbon, (Omsk, Russia).
JM-A series
Carbon Catalyst support from
Johnson Matthey, Inc., (W.
Deptford, NJ).
Calgon Carbon
Catalyst support from Calgon Corp.
under the brand name of Centaur ®
DHNE
Dihydronepetalactone
NELA
Nepetalactone
GC
Gas chromatography
Additionally, pressure is referred to in units of psi and MPa, where 14.7 psi is equivalent to 0.101325 MPa (which are both equivalent to 1 atm).
Catalyst Synthesis
A commercially available support such as carbon, alumina, or silica [available from Engelhard Corp. (E. Windsor, Conn.)] was impregnated by incipient wetness with a metal salt. The precursors used were
IrCl 3 .3H 2 O, PdCl 2 (Alfa Aesar, Wardhill, Mass.), RhCl 3 .xH 2 O (Alfa Aesar), RuCl 3 .xH 2 O (Aldrich Chemical Co., Milwaukee, Wis.), AuCl 3 .3H 2 O (Alfa Aesar), NiCl 2 .6H 2 O (Alfa Aesar), H 2 PtCl 6 (Johnson Matthey, Inc., W. Deptford, N.J.), and Re 2 O 7 (Alfa Aesar).
The samples were dried and reduced at 300-450° C. in H 2 for 2 hours.
The carbon used was commercially available as Calsicat Carbon, Sibunit Carbon, or Calgon Carbon. Calsicat Carbon is lot S-96-140 from Engelhard Corp., Beachwood, Ohio. Sibunit Carbon is Sibunit-2 from the Institute of Technical Carbon, 5th Kordnaya, Omsk 64418, Russia. Calgon Carbon is PCB Carbon (commercially available under the registered trademark of Centaur®) from Calgon Corp (Pittsburgh, Pa.).
Experiments 1-46
The present example describes a series of experiments conducted to test the abilities of various catalysts to selectively convert nepetalactone to dihydronepetalactone via hydrogenation. The only variable altered in each experiment was the type of catalyst and support, while the following parameters were held constant (unless specifically noted below):
time—2 hrs; temperature—50° C.; H 2 pressure—700 psi; and, feedstock—33% nepetalactone in ethanol.
Modifications to these “standard” parameters were made as noted:
Experiments 11, 16, 20, and 22
time—4 hrs; and
Experiment 17
time—3 hrs; H 2 pressure—1000 psi; and feedstock—50% nepetalactone in ethanol.
33% or 50% Nepetalactone in ethanol, and an amount of catalyst and support as indicated in the table below, were added to a 2 ml pressure reactor. The reactor was sealed and charged with 2.75 MPa of H 2 and heated to a reaction temperature of 50° C. The pressure was maintained at the desired level during the course of the reaction. The reaction was stopped after a 2 hr period of time and permitted to cool. An internal standard (methoxyethylether) was added into the reaction product mixture.
Analysis of the reaction product mixture was performed by gas chromatography. An HP-6890 GC employed a Chrompack column (CP-WAX 58, 25 M×25 MM) and a flame ionization detector. The temperature program was started at 50° C., then heated at 5° C./min to 80° C., and then heated to 270° C. at a rate of 10° C./min. The column flow rate was 1.5 cc/min He. The injector and detector temperatures were 280° C. and 350° C., respectively. GC analysis permitted determination of dihydronepetalactone selectivity [DHNE Sel (%)], acid selectivity [Acid Sel (%)], and nepetalactone conversion [NELA Con (%)]. DHNE Selectivity is the weight percent of the converted material that is dihydronepetalactone where the converted material is the portion (by weight) of the starting material that participates in the hydrogenation reaction. Acid selectivity is defined as the percent by weight in the converted material of the ring-opened product, methyl-2-isopropyl-5-methylcyclopentanecarboxylate.
For each experiment, the following table (Table 1) lists the catalyst, selectivity of the products, and conversion of the reactant. Data is presented such that the results from each specific catalyst (with variable supports) are presented in series.
TABLE 1
Hydrogenation of Nepetalactone
Exp't
DHNE
Acid
NELA
No.
Catalyst
Sel (%)
Sel (%)
Con (%)
1
5% Ir/Al 2 O 3
70.2
23.2
53.9
2
5% Ir/Calgon C
72.5
21.5
34.9
3
5% Ir/Calsicat C
45.2
16.2
46.9
4
5% Ir/Sibunit C
72.8
25.3
49.3
5
5% Ir/SiO 2
77.9
19.5
95.3
6
5% Ni/Al 2 O 3
12.1
0.0
6.2
7
5% Ni/Calgon C
8.6
0.0
7.8
8
5% Ni/Calsicat C
10.8
0.0
5.8
9
5% Ni/Sibunit C
74.6
0.0
0.7
10
5% Ni/SiO 2
37.9
0.0
2.0
11
5% Pd/Al 2 O 3 , JM-A22117-5
91.2
0.0
89.1
12
5% Pd/Al 2 O 3 , JM-A22117-5
83.8
0.0
99.9
13
5% Pd/Al 2 O 3 , JM-A302099-5
81.7
0.0
99.9
14
5% Pd/Al 2 O 3
78.7
17.0
99.5
15
5% Pd/BaSO 4 , JM-A22222-5
92.1
0.0
98.8
16
5% Pd/BaSO 4 , JM-A22222-5
70.3
0.0
68.8
17
5% Pd/C, JM-A503023-5
88.8
0.0
100.0
18
5% Pd/C, JM-A503023-5
80.0
13.8
100.0
19
5% Pd/C, ESCAT-142
78.9
16.4
100.0
20
5% Pd/C, ESCAT-142
25.4
0.0
21.5
21
5% Pd/CaCO 3 , JM-A21139-5
78.3
0.0
99.8
22
5% Pd/CaCO 3 , JM-A21139-5
71.2
0.0
65.7
23
5% Pd/Calgon C
54.3
15.9
72.6
24
5% Pd/Calsicat C
73.9
13.2
94.7
25
5% Pd/Sibunit C
60.7
18.0
69.9
26
5% Pd/SiO 2
72.2
16.0
100.0
27
5% Pt/Al 2 O 3
13.7
54.0
100.0
28
5% Pt/Calgon C
26.1
68.0
66.9
29
5% Pt/Calsicat C
15.4
54.6
79.9
30
5% Pt/Sibunit C
21.1
72.1
78.4
31
5% Pt/SiO 2
13.9
46.5
91.3
32
5% Re/Al 2 O 3
61.8
0.0
0.4
33
5% Re/Calgon C
12.8
0.0
1.8
34
5% Re/Calsicat C
15.5
3.9
33.6
35
5% Re/Sibunit C
19.1
5.0
22.3
36
5% Re/SiO 2
24.3
6.2
24.9
37
5% Rh/Al 2 O 3
82.2
15.6
99.9
38
5% Rh/Calgon C
80.3
12.1
99.1
39
5% Rh/Calsicat C
68.6
12.2
98.4
40
5% Rh/Sibunit C
81.2
15.9
99.0
41
5% Rh/SiO 2
83.4
14.5
99.9
42
5% Ru/Al 2 O 3
67.0
11.2
91.5
43
5% Ru/Calgon C
36.6
7.6
73.1
44
5% Ru/Calsicat C
41.0
6.8
69.6
45
5% Ru/Sibunit C
71.5
15.5
75.1
46
5% Ru/SiO 2
82.3
13.0
97.8
Preferred combinations of catalytic metal and support system includes
Ir/C (Sibunit C, Calsicat C, and Calgon C), Ir/Al 2 O 3 , Ir/SiO 2 , Pd/C (Sibunit C, Calsicat C, Calgon C, JM-A series, and ESCAT-142), Pd/Al 2 O 3 , Pd/BaSO 4 , Pd/CaCO 3 , Pd/SiO 2 , Rh/C (Sibunit C, Calsicat C, and Calgon C), Rh/Al 2 O 3 , Rh/SiO 2 , Ru/C (Sibunit C, Calsicat C, and Calgon C), Ru/Al 2 O 3 , and Ru/SiO 2 .
For the majority of experiments with these preferred combinations of catalytic metal and support system, yields of dihydronepetalactone were at least 70% selectivity. Experiment 15 achieved the highest yield of dihydronepetalactone (92.1%) with 98.8% conversion of nepetalactone using Pd/BaSO 4 .
Thus, a variety of Group 8 metals on various supports have been demonstrated to be active for hydrogenation of nepetalactone, permitting high yields in 2-4 hrs. This will result in significantly reduced scale-up costs as compared to methods of hydrogenation previously reported in the literature for production of dihydronepetalactones. | This invention relates to a process for hydrogenating nepetalactone, utilizing a metal catalyst that is optionally supported, to yield dihydronepetalactone. A suite of supported catalytic metals lead to rapid hydrogenation and high selectivity for dihydronepetalactone. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates generally to storage systems with thin provisioning and, more particularly, to the allocation of an area of logical volume to a virtual volume.
In recent years, thin provisioning has become popular. Thin provisioning is a method for allocating an area to a virtual volume when a storage subsystem receives a write command to an unallocated area. Existing methods allow a thin provisioning function to allocate an area randomly selected from several logical volumes to a virtual volume. Therefore, sequential access will become random access. When the storage subsystem receives sequential read command to consecutive areas, the response time will increase because the storage subsystem accesses randomly distributed areas and each HDD seeks a target sector. Sequential access performance will decrease. On the other hand, if the thin provisioning function allocates an area sequentially selected from one logical volume to a virtual volume, a lot of random accesses go to only the logical volume. Random access performance will decrease. An example for managing virtual volumes in a utility storage server system is found in U.S. Pat. No. 6,823,442.
BRIEF SUMMARY OF THE INVENTION
Exemplary embodiments of the invention provide a disk control program that allocates an area having portions selected from several logical volumes or a consecutive area of one logical volume based on predefined information when the disk control program receives a write command to an unallocated area. According to a first embodiment, an object allocation acquisition program obtains object allocation information. The disk control program identifies a written object when the disk control program receives a write command to an unallocated area. The disk control program allocates an area having portions selected from several logical volumes when the written object is predefined as a randomly accessed object. The disk control program allocates a consecutive area of one logical volume when the written object is predefined as a sequentially accessed object. According to a second embodiment, the disk control program identifies a target volume when the disk control program receives a write command to an unallocated area. The disk control program allocates an area having portions selected from several logical volumes when the target volume is predefined as a randomly accessed volume. The disk control program allocates a consecutive area of one logical volume when the target volume is predefined as a sequentially accessed volume.
In accordance with an aspect of the present invention, a storage system comprises a processor; a memory; a disk control module configured to receive a write command for writing to an unallocated area and to identify an object of the write command to be written as a written object; and an object allocation acquisition module configured to obtain object allocation information specifying one or more virtual volume locations for storing the written object. The disk control module allocates, to each of the one or more virtual volume locations, an area selected from a plurality of logical volumes if the written object is predefined as a randomly accessed object. The disk control module allocates to the one or more virtual volume locations a consecutive area of one logical volume if the written object is predefined as a sequentially accessed object.
In some embodiments, the disk control program is configured to update virtual volume information correlating one or more logical volume locations of the allocated area with the one or more virtual volume locations for storing the written object. The one or more logical volume locations include a logical volume name and one or more logical volume addresses, and wherein the one or more virtual volume locations include a virtual volume name and one or more virtual volume addresses. The disk control program is configured to obtain the one or more virtual volume locations for storing the written object from the object allocation information; obtain one or more logical volume locations corresponding to the obtained one or more virtual volume locations based on virtual volume information; obtain one or more RAID group names and addresses corresponding to the obtained one or more logical volume locations based on logical volume information; obtain a media name corresponding to the obtained one or more RAID group names and addresses based on RAID group information; and write data of the write command to media corresponding to the obtained media name.
In specific embodiments, the disk control program is configured to obtain the one or more virtual volume locations for storing the written object from the object allocation information, obtain one or more logical volume locations corresponding to the one or more virtual volume locations based on virtual volume information, and obtain one or more RAID group names and addresses corresponding to the obtained one or more logical volume locations based on logical volume information. If the written object is predefined as a randomly accessed object, then for the area to be allocated to each one of the one or more virtual volume locations, the disk control module selects from the one or more RAID group names and addresses a RAID group which has a least amount of assigned capacity, selects a logical volume which is associated with the selected RAID group, and allocates a portion of the selected logical volume as the selected area to the one virtual volume location. If the written object is predefined as a sequentially accessed object and if the disk control module finds a virtual volume name and virtual volume address of an adjacent previous address of an object address of the written object, the disk control program obtains the virtual volume name and virtual volume address of the adjacent previous address from the object allocation information, obtains a logical volume name and a logical volume address allocated to the virtual volume name and the virtual volume address of the adjacent previous address, obtains an adjacent subsequent address of the logical volume address of the adjacent previous address, and allocates an area of the adjacent subsequent address as the consecutive area of one logical volume to the one or more virtual volume locations for storing the written object. If the written object is predefined as a sequentially accessed object and if the disk control module does not find a virtual volume name and virtual volume address of an adjacent previous address of an object address of the written object, the disk control program allocates an area of a logical volume of a RAID group for which an access type is SEQUENTIAL.
In some embodiments, the storage system further comprises a move module. An access type of the written object is changed to a changed object from a randomly accessed object to a sequentially accessed object or from a sequentially accessed object to a randomly accessed object. If the access type of the changed object is changed from a sequentially accessed object to a randomly accessed object, the changed object has an object name and a plurality of object addresses, and for each object address of the object addresses of the changed object, the move module obtains the virtual volume name and the virtual volume address corresponding to the object name and the object address of the changed object, obtains the logical volume name and the logical volume address corresponding to the obtained virtual volume name and the virtual volume address, obtains one or more RAID group names and addresses corresponding to the obtained logical volume name and the logical volume address, selects from the one or more RAID group names and addresses a RAID group which has a least amount of assigned capacity, selects a logical volume for random access which is associated with the selected RAID group, and moves data from an area associated with the obtained logical volume name and the logical volume address of the changed object to the selected logical volume for random access. If the access type of the changed object is changed from a randomly accessed object to a sequentially accessed object, the move module selects a RAID group for which the access type is SEQUENTIAL, selects a logical volume for which a RAID group name is associated with the selected RAID group, obtains a source address of the changed object based on the object allocation information and on virtual volume information which correlates virtual volume name and address with logical volume name and address, and moves data from the source address to the selected logical volume.
In accordance with another aspect of this invention, a storage system comprises a processor; a memory; a disk control module configured to receive a write command for writing to an unallocated area and to identify a target volume for an object of the write command to be written as a written object; and an object allocation acquisition module configured to obtain object allocation information specifying one or more virtual volume locations for storing the written object. The disk control module allocates, to each of the one or more virtual volume locations, an area selected from a plurality of logical volumes if the target volume is predefined as a randomly accessed volume. The disk control module allocates to the one or more virtual volume locations a consecutive area of one logical volume if the target volume is predefined as a sequentially accessed volume.
In accordance with another aspect of the invention, a storage system comprises a processor; a memory; a disk control module configured to receive a write command for writing to an unallocated area, and to identify an object of the write command to be written as a written object or a target volume for an object of the write command to be written as a written object; and an object allocation acquisition module configured to obtain object allocation information specifying one or more virtual volume locations for storing the written object. If the disk control module identifies a written object of the write command, the disk control module allocates to the one or more virtual volume locations an area having portions selected from a plurality of logical volumes if the written object is predefined as a randomly accessed object, and allocates to the virtual volume location a consecutive area of one logical volume if the written object is predefined as a sequentially accessed object. If the disk control module identifies a written object of the write command, the disk control module allocates, to each of the one or more virtual volume locations, an area selected from a plurality of logical volumes if the written object is predefined as a randomly accessed object, and the disk control module allocates to the one or more virtual volume locations a consecutive area of one logical volume if the written object is predefined as a sequentially accessed object. If the disk control module identifies a target volume for a written object of the write command, the disk control module allocates, to each of the one or more virtual volume locations, an area selected from a plurality of logical volumes if the target volume is predefined as a randomly accessed volume, and the disk control module allocates to the one or more virtual volume locations a consecutive area of one logical volume if the target volume is predefined as a sequentially accessed volume.
In some embodiments, if the disk control module identifies a written object of the write command, then the disk control program is configured to obtain the one or more virtual volume locations for storing the written object from the object allocation information, obtain one or more logical volume locations corresponding to the obtained one or more virtual volume locations based on virtual volume information, and obtain one or more RAID group names and addresses corresponding to the obtained one or more logical volume locations based on logical volume information.
These and other features and advantages of the present invention will become apparent to those of ordinary skill in the art in view of the following detailed description of the specific embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an example of a hardware configuration of an information system in which the method and apparatus of the invention may be applied
FIG. 2 illustrates an example of the memory in the application server and the memory in the storage subsystem of FIG. 1 .
FIG. 3 illustrates an example of the object allocation information in the storage subsystem of FIG. 1 , a read command, and a write command.
FIG. 4 shows an example of the RAID group information, the logical volume information, and the pool information.
FIG. 5 shows an example of the virtual volume information, the access type definition information, and the object assignment information according to the first embodiment.
FIG. 6 shows an example of an access type setting screen according to the first embodiment.
FIG. 7 shows an example of a diagram illustrating relationships between table and virtual volume, virtual volume and logical volume, and logical volume and RAID group.
FIG. 8 is an example of a flow diagram showing that the storage subsystem reads data from the SSD and the HDD, and writes data to the SSD and the HDD when the storage subsystem receives the read command or the write command from the application server.
FIG. 9 is an example of a flow diagram showing the disk control program allocates an area of a virtual volume to an unallocated area in step 804 of FIG. 8 according to the first embodiment.
FIG. 10 is an example of a flow diagram showing a process when the access type definition information is changed using the access type setting screen.
FIG. 11 illustrates an example of the access type definition information, the object assignment information, and the access type setting screen according to the second embodiment.
FIG. 12 is an example of a flow diagram showing the disk control program allocates an area of a virtual volume to an unallocated area in step 804 of FIG. 8 according to second embodiment.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description of the invention, reference is made to the accompanying drawings which form a part of the disclosure, and in which are shown by way of illustration, and not of limitation, exemplary embodiments by which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. Further, it should be noted that while the detailed description provides various exemplary embodiments, as described below and as illustrated in the drawings, the present invention is not limited to the embodiments described and illustrated herein, but can extend to other embodiments, as would be known or as would become known to those skilled in the art. Reference in the specification to “one embodiment,” “this embodiment,” or “these embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention, and the appearances of these phrases in various places in the specification are not necessarily all referring to the same embodiment. Additionally, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details may not all be needed to practice the present invention. In other circumstances, well-known structures, materials, circuits, processes and interfaces have not been described in detail, and/or may be illustrated in block diagram form, so as to not unnecessarily obscure the present invention.
Furthermore, some portions of the detailed description that follow are presented in terms of algorithms and symbolic representations of operations within a computer. These algorithmic descriptions and symbolic representations are the means used by those skilled in the data processing arts to most effectively convey the essence of their innovations to others skilled in the art. An algorithm is a series of defined steps leading to a desired end state or result. In the present invention, the steps carried out require physical manipulations of tangible quantities for achieving a tangible result. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals or instructions capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, instructions, or the like. It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, can include the actions and processes of a computer system or other information processing device that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system's memories or registers or other information storage, transmission or display devices.
The present invention also relates to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may include one or more general-purpose computers selectively activated or reconfigured by one or more computer programs. Such computer programs may be stored in a computer-readable storage medium, such as, but not limited to optical disks, magnetic disks, read-only memories, random access memories, solid state devices and drives, or any other types of media suitable for storing electronic information. The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs and modules in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform desired method steps. In addition, the present invention is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein. The instructions of the programming language(s) may be executed by one or more processing devices, e.g., central processing units (CPUs), processors, or controllers.
Exemplary embodiments of the invention, as will be described in greater detail below, provide apparatuses, methods and computer programs for the allocation of an area of logical volume to a virtual volume based on object access type.
First Embodiment: Object-Based Access Type Management System Configuration
FIG. 1 illustrates an example of a hardware configuration of an information system in which the method and apparatus of the invention may be applied. The system comprises an application server 100 , a SAN (Storage Area Network) 120 , a LAN (Local Area Network) 140 , and a storage subsystem 160 . The application server 100 comprises a CPU (Central Processing Unit) 101 , a memory 102 , a HDD (Hard Disk Drive) 103 , a SAN interface 104 , and a LAN interface 105 . The CPU 101 reads programs from the memory 102 and executes the programs. The memory 102 reads programs and data from the HDD 103 when the application server 100 starts and stores the programs and the data. The HDD 103 stores programs and data. The SAN interface 104 connects the application server 100 and the SAN 120 . The LAN interface 105 connects the application server 100 and the LAN 140 . The SAN 120 connects the application server 100 and the storage subsystem 160 . The application server 100 uses the SAN 120 to send application data to the storage subsystem 160 and receive application data from the storage subsystem 160 . The application server 100 uses the LAN 140 to send management data to the storage subsystem 160 and receive management data from the storage subsystem 160 . The LAN 140 connects the application server 100 and the storage subsystem 160 . The storage subsystem 160 comprises a SAN interface 161 , a LAN interface 162 , a CPU 163 , a memory 164 , a disk interface 165 , a SSD (Solid State Drive) 166 , and a HDD 167 . The SAN interface 161 connects the storage subsystem 160 and the SAN 120 . The LAN interface 162 connects the storage subsystem 160 and the LAN 140 . The CPU 163 reads programs from the memory 164 and executes the programs. The memory 164 reads programs and data from the HDD 167 and SSD 166 when the storage subsystem 160 starts and stores the programs and the data. The disk interface 165 connects the storage subsystem 160 , the SSD 166 , and the HDD 167 . The SSD 166 stores programs and data. The HDD 167 stores programs and data.
FIG. 2 illustrates an example of the memory 102 in the application server 100 and the memory 164 in the storage subsystem 160 of FIG. 1 . The memory 102 comprises an OS (Operating System) program 201 , an application program 202 , and object allocation information 203 . The OS program 201 executes the application program 202 . The application program 202 (e.g., database program) reads data from the storage subsystem 160 , processes data, writes the results to the storage subsystem 160 , and manages the object allocation information 203 . The object allocation information 203 includes a location where an object is saved.
The memory 164 comprises a disk control program 221 , RAID (Redundant Arrays of Inexpensive (or Independent) Disks) group information 222 , logical volume information 223 , pool information 224 , virtual volume information 225 , access type definition information 226 , object assignment information or allocation information 227 , a move program 228 , and an object allocation acquisition program 229 . The disk control program 221 receives a read command and a write command from the application server 100 , reads data from the SSD 166 and the HDD 167 , and writes data to the SSD 166 and the HDD 167 using the RAID group information 222 , the logical volume information 223 , the pool information 224 , the virtual volume information 225 , and the access type definition information 226 . The move program 228 moves data to some other area.
FIG. 3 illustrates an example of the object allocation information 203 in the storage subsystem 160 of FIG. 1 , a read command 340 , and a write command 360 . The object allocation information 203 of FIG. 3 is a table and includes columns of an object name 301 , an object address 302 , a virtual volume name 303 , and a virtual volume address 304 . For example, the row 305 shows that the address from “0” to “99” in “TABLE A” is allocated to the address from “0” to “99” in “V-VOL A.”
The read command 340 includes a command type 341 , a volume name 342 , and a volume address 343 . The read command 340 is sent from the application program 202 to the disk control program 221 . The write command 360 includes a command type 361 , a volume name 362 , a volume address 363 , and data 364 . The write command 360 is sent from the application program 202 to disk control program 221 .
FIG. 4 shows an example of the RAID group information 222 , the logical volume information 223 , and the pool information 224 .
The RAID group information 222 includes columns of a RAID group name 401 , a media name 402 , a RAID level 403 , and an access type 404 . For example, the row 405 shows that “RG A” has “HDD A,” “HDD B,” “HDD C,” and “HDD D,” the RAID level of “RG A” is “RAID 5 (3D+1P),” and “RG A” is used for random access.
The logical volume information 223 includes columns of a logical volume name 421 , a logical volume address 422 , a RAID group name 423 , and a RAID group address 424 . For example, the row 425 shows that “L-VOL A” is allocated to the address from “0” to “999” in “RG A.”
The pool information 224 includes columns of a pool name 441 , a logical volume name for random access 442 , a logical volume name for sequential access 443 , and a virtual volume name 444 . For example, the row 445 shows “POOL A” has “L-VOL A”, “L-VOL B,” and “L-VOL C” for random access and “L-VOL D” and “L-VOL E” for sequential access, and the area of “POOL A” is used by “V-VOL A.”
FIG. 5 shows an example of the virtual volume information 225 , the access type definition information 226 , and the object assignment information 227 according to the first embodiment.
The virtual volume information 225 includes columns of a virtual volume name 501 , a virtual volume address 502 , a logical volume name 503 , and a logical volume address 504 . For example, the row 505 shows that the address from “0” to “99” in “V-VOL A” is allocated to the address from “0” to “99” in “L-VOL A.”
The access type definition information 226 includes columns of an object name 521 and an access type 522 . For example, the row 523 shows “TABLE A” is accessed randomly and the row 524 shows “TABLE B” is accessed sequentially.
The object assignment information 227 includes columns of an object name 541 , a RAID group name 542 , and assigned capacity 543 . The RAID group name 542 shows a list of RG names for which the access type 404 is only “RANDOM” in the RAID group information 222 . For example, the row 544 shows “TABLE A” is assigned with an area in “RG A” and the assigned capacity is 100 bytes.
FIG. 6 shows an example of an access type setting screen 600 according to the first embodiment. An administrator inputs an object name 601 and an access type 602 . The access type definition information 226 is updated to the data input by the administrator when the administrator pushes an “OK” button 621 .
FIG. 7 shows an example of a diagram illustrating relationships between table and virtual volume, virtual volume and logical volume, and logical volume and RAID group. FIG. 7 shows TABLE A 701 , TABLE B 702 , V-VOL A 703 , L-VOL A 704 , L-VOL B 705 , L-VOL C 706 , L-VOL D 707 , RG A 708 , RG B 709 , RG C 710 , and RG D 711 . For example, the address “0” to “99” in the TABLE A 701 is mapped to the address “0” to “99” in the V-VOL A 703 , the address “0” to “99” in the V-VOL A 703 is mapped to the address “0” to “99” in the L-VOL A 704 , and the address “0” to “999” in the L-VOL A 704 is mapped to the address “0” to “999” in the RG A 708 . FIG. 7 shows object assignment for randomly accessed object amongst L-VOL A and RG A, L-VOL B AND RG B, and L-VOL C and RG C. FIG. 7 further shows object assignment for sequentially accessed object to L-VOL D and RG D.
Process Flows
FIG. 8 is an example of a flow diagram showing that the storage subsystem 160 reads data from the SSD 166 and the HDD 167 , and writes data to the SSD 166 and the HDD 167 when the storage subsystem 160 receives the read command 340 or the write command 360 from the application server 100 .
In step 801 , the disk control program 221 receives the read command 340 or the write command 360 from the application server 100 . In decision step 802 , if the command that the disk control program 221 received in step 801 is the write command 360 , then the process goes to decision step 803 ; if not, then the process goes to decision step 806 . In decision step 803 , if the volume name 362 and the volume address 363 are allocated in the virtual volume information 225 , then the process goes to step 805 ; if not, then the process goes to step 804 .
In step 804 , the disk control program 221 allocates an area and updates the virtual volume information 225 . In step 805 , the disk control program 221 gets the volume name 362 and the volume address 363 from the write command 360 , gets the logical volume name 503 and the logical volume address 504 from the virtual volume information 225 , gets the RAID group name 423 and the RAID group address 424 from the logical volume information 223 , gets the media name 402 from the RAID group information 222 , and writes the data 364 the SSD 166 and the HDD 167 .
In decision step 806 , if the volume name 342 and the volume address 343 are allocated in the virtual volume information 225 , then the process goes to step 808 ; if not, then the process goes to step 807 . In step 807 , the disk control program 221 returns “0” to the application server 100 because the area specified by the volume name 342 and the volume address 343 is not one to which data is written. In step 808 , the disk control program 221 gets the volume name 342 and the volume address 343 from the read command 340 , gets the logical volume name 503 and the logical volume address 504 from the virtual volume information 225 , gets the RAID group name 423 and the RAID group address 424 from the logical volume information 223 , gets the media name 402 from the RAID group information 222 , and reads data from the SSD 166 and the HDD 167 .
FIG. 9 is an example of a flow diagram showing the disk control program 221 allocates an area of a virtual volume to an unallocated area in step 804 of FIG. 8 according to the first embodiment.
In step 901 , the object allocation acquisition program 229 gets the object allocation information 203 from the application server 100 . In step 902 , the disk control program 221 identifies the object to which the data 364 is written from the volume name 362 , the volume address 363 , and the object allocation information 203 . For example, the volume name 362 is “V-VOL A” and the volume address 363 is “300” to “399” and the area “300” to “399” of “L-VOL A” corresponds to the address “200” to “299” of “TABLE A.” Therefore, the data 364 is written to “TABLE A.” In step 903 , the disk control program 221 gets the access type 522 from the object name which is identified in step 902 and the access type definition information 226 . For example, the object name which is identified in step 902 is “TABLE A.” The access type 522 of “TABLE A” is “RANDOM” from the row 523 in the access type definition information 226 . In decision step 904 , if the access type 522 which the disk control program 221 gets in step 903 is “RANDOM,” then the process goes to step 905 ; if not, the process goes to step 908 .
In step 905 , the disk control program 221 selects a RAID group to allocate an area to a virtual volume. The disk control program 221 selects a RAID group that has the least amount of assigned capacity 543 among the objects associated with the object name 541 identified in step 902 . For example, when identified object name is “INDEX A” in step 902 , “RG C” is the least assigned capacity among “RG A,” “RG B,” and “RG C.” In step 906 , the disk control program 221 selects a logical volume to allocate an area to a virtual volume. The disk control program 221 selects the logical volume name 421 for the logical volume which is associated with the RAID group under the RAID group name 423 selected in step 905 . For example, when “RG C” is selected in step 905 , the disk control program 221 selects “L-VOL C.” In step 907 , the disk control program 221 allocates an area of the logical volume that is selected in step 906 to the virtual volume that is specified by the volume name 362 and the volume address 363 , and updates the virtual volume information 225 .
The selection of a RAID group that has the least amount of assigned capacity in step 905 ensures that data is written approximately evenly across the RAID groups and corresponding logical volumes. As such, the disk control program 221 allocates to the virtual volumes approximately evenly from the logical volumes. For a randomly accessed object to be stored in one or more virtual volume locations (i.e., a virtual volume name and one or more virtual volume addresses), the area to be allocated to each one of the virtual volume locations is selected from one of the logical volumes. Steps 905 to 907 are performed for each one of the virtual volume locations.
In step 908 , the disk control program 221 gets the object name 301 and the object address 302 from the write command 360 and the object allocation information 203 . For example, the volume name 362 is “V-VOL A” and the volume address 363 is “500” to “599,” and hence the object name 301 is “TABLE B” and the object address 302 is “200” to “299.” In step 909 , the disk control program 221 gets the adjacent previous address of the object address obtained in step 908 . For example, the object name obtained in step 908 is “TABLE B” and the object address obtained in step 908 is “200” to “299,” and thus the adjacent previous address is “100” to “199.” In decision step 910 , if the disk control program 221 finds the virtual volume name 303 and the virtual volume address 304 of the adjacent previous address, then the process goes to step 911 ; if not, the process goes to step 915 . In step 911 , the disk control program 221 gets the virtual volume name 303 and the virtual volume address 304 of the adjacent previous address obtained in step 909 from the object allocation information 203 . For example, the adjacent previous address obtained in step 909 is “100” to “199,” and hence the virtual volume name 303 is “V-VOL A” and the virtual volume address 304 is “400” to “499.” In step 912 , the disk control program 221 gets the logical volume name 503 and the logical volume address 504 allocated to the virtual volume and the virtual volume address obtained in step 911 from the virtual volume information 225 . For example, the virtual volume name 303 is “V-VOL A” and the virtual volume address 304 is “400” to “499” obtained in step 911 , and thus the logical volume name 503 is “L-VOL D” and the logical volume address 504 is “100” to “199.” In step 913 , the disk control program 221 gets the adjacent subsequent address of the logical volume address obtained in step 912 . For example, the logical volume name 503 is “L-VOL D” and the logical volume address 504 is “100” to “199” obtained in step 912 ; therefore, the subsequent address is “200” to “299.” In step 914 , the disk control program 221 allocates the area obtained in step 913 to the virtual volume specified by the volume name 362 and the volume address 363 . In step 915 , the disk control program 221 allocates an area of a logical volume of a RAID group that has the access type 404 of “SEQUENTIAL.”
FIG. 10 is an example of a flow diagram showing a process when the access type definition information 226 is changed using the access type setting screen 600 . In step 1001 , the move program 228 updates the access type definition information 226 with changed information from the access type setting screen 600 . In step 1002 , the move program 228 gets the object allocation information 203 from the application server 100 . In step 1003 , the move program 228 selects a changed object from the access type definition information 226 . In decision step 1004 , if the access type 522 of the object selected in step 1003 is changed from “SEQUENTIAL” to “RANDOM,” then the process goes to step 1005 ; if not, then the process goes to step 1010 .
In step 1005 , the move program 228 selects a row in which the object name 301 is for the object selected in step 1003 in the object allocation information 203 , selects a row in which the virtual volume name 501 and the virtual volume address are the same as the virtual volume name 303 and the virtual volume address 304 selected in this step, and gets the logical volume name 503 and the logical volume address 504 selected in this step from the virtual volume information 225 . For example, when the access type 522 of “TABLE B” is changed from “SEQUENTIAL” to “RANDOM,” the move program 228 selects the row 307 from the object allocation information 203 , selects the row 507 from the virtual volume information 225 , and gets the logical volume name 503 which is “L-VOL D” and the logical volume address 504 which is “0” to “99.” In step 1006 , the move program 228 selects a RAID group for random access. The move program 228 selects a RAID group that has the least amount of assigned capacity 543 among the objects associated with the object name 541 selected in step 1003 . For example, when the selected object name is “INDEX A” in step 1003 , “RG C” is the least assigned capacity among “RG A,” “RG B,” and “RG C.” In step 1007 , the move program 228 selects a logical volume for random access. The move program 228 selects the logical volume name 421 for which the RAID group name 423 is associated with the RAID group that is selected in step 1006 . For example, when “RG C” is selected in step 1006 , the disk control program 221 selects “L-VOL C.” In step 1008 , the move program 228 moves data from the area selected in step 1005 to the area selected in step 1007 and updates the virtual volume information 225 . In step 1009 , if the move program 228 moves the object selected in step 1003 , then the process goes to step 1013 ; if not, then the process goes to step 1005 .
In step 1010 , the move program 228 selects a RAID group for which the access type 404 is “SEQUENTIAL.” In step 1011 , the move program 228 selects a logical volume for which the RAID group name 423 is associated with the RAID group selected in step 1010 . In step 1012 , the move program 228 gets the source address of the object selected in step 1003 from the object allocation information 203 and the virtual volume information 225 , moves data from the source address to the logical volume selected in step 1011 , and updates the virtual volume information 225 . The process continues to step 1013 .
In decision step 1013 , if all changed objects are moved, then the process ends; if not, then the process goes to step 1003 .
Second Embodiment: Volume-Based Access Type Management
The following description of the second embodiment focuses on only the differences from the first embodiment.
System Configuration
FIG. 11 illustrates an example of the access type definition information 226 , the object assignment information 227 , and the access type setting screen 600 according to the second embodiment.
The access type definition information 226 includes columns of a virtual volume name 1101 and an access type 1102 . For example, the row 1103 shows “V-VOL A” is accessed randomly and the row 1104 shows “V-VOL B” is accessed sequentially. The object assignment information 227 includes columns of a virtual volume name 1121 , a RAID group name 1122 , and assigned capacity 1123 . The RAID group name 1122 shows a list of RG names for which the access type 404 is only “RANDOM” in the RAID group information 222 . For example, the row 1124 shows “V-VOL A” is assigned with an area in “RG A” and the assigned capacity is 100 bytes. An administrator inputs a virtual volume name 1141 and an access type 1142 on the access type setting screen 600 . The access type definition information 226 is updated to the data input by the administrator when the administrator pushes an “OK” button 1146 .
Process Flows
FIG. 12 is an example of a flow diagram showing the disk control program 221 allocates an area of a virtual volume to an unallocated area in step 804 of FIG. 8 according to second embodiment.
In step 1202 , the disk control program 221 identifies the virtual volume to which the data 364 is written from the volume name 362 . In step 1203 , the disk control program 221 gets the access type 1102 from the virtual volume name which is identified in step 1202 and the access type definition information 226 . For example, the virtual volume name which is identified in step 1202 is “V-VOL A.” The access type 1102 of “V-VOL A” is “RANDOM” from the row 1103 in the access type definition information 226 . In decision step 1204 , if the access type 1102 which the disk control program 221 gets in step 1203 is “RANDOM”, then the process goes to step 1205 ; if not, the process goes to step 1209 .
In step 1205 , the disk control program 221 selects a RAID group to allocate an area to a virtual volume. The disk control program 221 selects a RAID group that has the least amount of assigned capacity 1123 among the objects associated with the virtual volume name 1121 identified in step 1202 . For example, when the identified object name is “V-VOL C” in step 1202 , “RG C” is the least assigned capacity among “RG A,” “RG B,” and “RG C.” In step 1206 , the disk control program 221 selects a logical volume to allocate an area to a virtual volume. The disk control program 221 selects the logical volume name 421 for which the RAID group name 423 is associated with the RAID group that is selected in step 1205 . For example, when “RG C” is selected in step 1205 , the disk control program 221 selects “L-VOL C.” In step 1207 , the disk control program 221 allocates an area of the logical volume that is selected in step 1206 to the virtual volume that is specified by the volume name 362 and the volume address 363 , and updates the virtual volume information 225 .
In step 1209 , the disk control program 221 gets the adjacent previous address of the object address specified by the write command 360 . For example, the volume name 362 is “V-VOL A” and the volume address 363 is “500” to “599,” and hence the adjacent previous address is “400” to “499.” In step 1212 , the disk control program 221 gets the logical volume name 503 and the logical volume address 504 allocated to the virtual volume and the virtual volume address obtained in step 1209 from the virtual volume information 225 . For example, the virtual volume name 501 obtained in step 1209 is “V-VOL A” and the virtual volume address 502 obtained in step 1212 is “400” to “499”, and thus the logical volume name 503 is “L-VOL D” and the logical volume address 504 is “100” to “199.” In step 1213 , the disk control program 221 gets the subsequent address of the logical volume address obtained in step 1212 . For example, the logical volume name 503 is “L-VOL D” and the logical volume address 504 is “100” to “199” obtained in step 1212 , and hence the adjacent subsequent address is “200” to “299.” In step 1214 , the disk control program 221 allocates the area obtained in step 1213 to the virtual volume specified by the volume name 362 and the volume address 363 .
Of course, the system configuration illustrated in FIG. 1 is purely exemplary of information systems in which the present invention may be implemented, and the invention is not limited to a particular hardware configuration. The computers and storage systems implementing the invention can also have known I/O devices (e.g., CD and DVD drives, floppy disk drives, hard drives, etc.) which can store and read the modules, programs and data structures used to implement the above-described invention. These modules, programs and data structures can be encoded on such computer-readable media. For example, the data structures of the invention can be stored on computer-readable media independently of one or more computer-readable media on which reside the programs used in the invention. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include local area networks, wide area networks, e.g., the Internet, wireless networks, storage area networks, and the like.
In the description, numerous details are set forth for purposes of explanation in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that not all of these specific details are required in order to practice the present invention. It is also noted that the invention may be described as a process, which is usually depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged.
As is known in the art, the operations described above can be performed by hardware, software, or some combination of software and hardware. Various aspects of embodiments of the invention may be implemented using circuits and logic devices (hardware), while other aspects may be implemented using instructions stored on a machine-readable medium (software), which if executed by a processor, would cause the processor to perform a method to carry out embodiments of the invention. Furthermore, some embodiments of the invention may be performed solely in hardware, whereas other embodiments may be performed solely in software. Moreover, the various functions described can be performed in a single unit, or can be spread across a number of components in any number of ways. When performed by software, the methods may be executed by a processor, such as a general purpose computer, based on instructions stored on a computer-readable medium. If desired, the instructions can be stored on the medium in a compressed and/or encrypted format.
From the foregoing, it will be apparent that the invention provides methods, apparatuses and programs stored on computer readable media for the allocation of an area of logical volume to a virtual volume. Additionally, while specific embodiments have been illustrated and described in this specification, those of ordinary skill in the art appreciate that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments disclosed. This disclosure is intended to cover any and all adaptations or variations of the present invention, and it is to be understood that the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with the established doctrines of claim interpretation, along with the full range of equivalents to which such claims are entitled. | In accordance with an aspect of the invention, a storage system includes a processor; a memory; a disk control module configured to receive a write command for writing to an unallocated area and to identify an object of the write command to be written as a written object; and an object allocation acquisition module configured to obtain object allocation information specifying one or more virtual volume locations for storing the written object. The disk control module allocates, to each of the one or more virtual volume locations, an area selected from a plurality of logical volumes if the written object is predefined as a randomly accessed object. The disk control module allocates to the one or more virtual volume locations a consecutive area of one logical volume if the written object is predefined as a sequentially accessed object. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to creosote cutters for cleaning creosote out of chimneys and more particularly pertains to a new and improved mounting bracket assembly which is designed primarily for supporting creosote cutters which are permanently installed within a chimney flue.
2. Description of the Prior Art
Creosote cutters and other types of chimney cleaners are well known in the prior art. In this connection, reference is made to U.S. Pat. No. 4,409,703 which issued to the present inventor on Oct. 18, 1983 and the disclosure of which is incorporated herein by reference. The creosote cutter disclosed in the inventor's prior patent is permanently positioned within a chimney flue and is movably supported from a pulley through the use of a flexible chain or the like. An operator may manually move the chain over the pulley to effectively move the creosote cutter up and down within the chimney, while in the various embodiments of the invention, the cutter may be operated from an exterior position outside of the chimney, such as at ground level, or alternatively, the flexible pulling chain may be directed downwardly through the chimney so as to permit an operator to operate the cutter through an interiorly positioned access or cleanout door normally provided with coal, wood and similar types of fire boxes.
Additionally disclosed in the inventor's prior patent are various embodiments of supporting and guiding mounting bracket assemblies which, although each functions precisely in the desired manner, are so constructed as to require the manufacture and assembly of a plurality of separable parts. Through continued experimentation, the inventor of the present invention has determined that it is desirable to simplify the construction of the mounting and supporting bracket assemblies associated with the embodiments of his prior invention, and it is to such improvements that the present invention is directed.
SUMMARY OF THE INVENTION
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a chimney cleaner mounting bracket assembly which possesses all of the advantages of the prior art chimney cleaner mounting bracket assemblies and none of the disadvantages. To attain this, the chimney cleaner mounting bracket assembly forming the present invention utilizes a bracket mountable to a topmost portion of a chimney, such bracket serving to support a creosote cutter or cutter bar normally retained within the flue of the chimney. More specifically, the bracket is of an integral construction and is mounted to the top of the chimney through the use of at least one strip of banding iron which is tightly fastened around a periphery of the chimney or its flue. The bracket includes banding guides, through which the banding iron is directed to retain the bracket in position, and further includes orthogonally-positioned support plates which are integrally or otherwise fixedly attached to the bracket. The support plates are designed to bear against a topmost portion of the chimney, thus to support the weight of a creosote cutter supported by the bracket.
The bracket further includes a substantially centrally positioned roller or pulley assembly which essentially consists of a piece of cylindrical pipe freely supported by and rotatable on the bracket, while being held in position by a pair of fixedly positioned stops. The creosote cutter supporting chain is directed over the pipe section with the pipe then being rotatably movable on the bracket in response to a movement of the chain, whereby the pipe section functions as the aforementioned pulley or roller.
The invention further includes a novel attachment bracket which functions to connect the creosote cutter to its supporting chain. The bracket consists of a plate having a metallic loop riveted thereto, with the metallic loop extending through a chain link. While the metallic loop is attached to a topmost surface of the plate, a further metallic loop is interconnected to a bottommost portion of the plate and is bent substantially into the form of an eye. A cutter support member includes a metallic loop directed through the eye so as to complete the attachment of the cutter to the supporting chain.
It is therefore an object of the present invention to provide a creosote removing chimney cleaner mounting bracket assembly that has all of the advantages of the prior art chimney cleaner mounting bracket assemblies and none of the disadvantages.
Another object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly which is simply constructed and which is designed with a minimum of separable and moving parts.
Yet another object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly which may be efficiently, easily and economically manufactured.
Still another object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly that provides for a reliable and durable operable attachment of a chimney cleaner within a chimney.
A further object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly which may be easily and rapidly attached to existing chimney structures.
Even another object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly that may be permanently attached to an existing chimney.
A still further object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly that facilitates the operation of the associated chimney cleaner by a user with a minimum of time and effort.
Even another object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly which is characterized by a portable and lightweight construction.
Still even a further object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such devices economically available to the buying public.
Even still another object of the present invention is to provide a creosote removing chimney cleaner mounting bracket assembly which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view, partly in cross-section, illustrating the attachment of the mounting bracket assembly forming the present invention to a conventional chimney.
FIG. 2 is a partial cross-sectional detail view taken along the line 2--2 in FIG. 1.
FIG. 3 is a perspective view of the mounting bracket forming a part of the present invention.
FIG. 4 is a side detail view illustrating the banding guides forming a part of the present invention.
FIG. 5 is a detail view, partly in cross-section, illustrating the operable attachment of the support plate forming a part of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings and in particular to FIG. 1 thereof, a preferred embodiment of the creosote cutter mounting bracket assembly embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described. In the interest of brevity, reference should be had to the disclosure of U.S. Pat. No. 4,409,703, incorporated herein by reference, for a complete understanding of the design and function of a creosote cutter 12 operably positioned within the flue 14 of a chimney 16. The present invention deals only with the mounting bracket assembly 10 and not with the specific design and use of the creosote cutter 12 and the discussion relative thereto is thus limited.
As shown, however, the cutter 12 includes a plurality of topmost positioned cutting teeth 18 and a further plurality of bottommost cutting teeth 20 with the function of such teeth being to scrape away creosote and other debris which accumulates on the inside surface of the flue 14 as the result of a combustion process occurring within a firebox 22. The cutter 12 is typically designed to conform to the interior shape of the flue 14 so as to facilitate the movement of the cutter upwardly and downwardly within the flue. In this regard, the cutter 12, which is shown as being positioned near a topmost portion of the flue 14 in FIG. 1, may be selectively manually moved through a pulling of the chain 24 downwardly within the flue until the cutter reaches a position 26 as indicated by phantom lines. Of course, through a further manual operation of the chain 24, the cutter 12 may be returned to its topmost position within the chimney 16, and such manual operation may be accomplished from a position exterior of the chimney or alternatively, an interior operation may be accomplished by an operator by his achieving access to the chain through an access or cleanout door 28. A more complete description of the interior and exterior operable positioning of the chain 24 is given in U.S. Pat. No. 4,409,703.
Referencing FIGS. 2 and 3 in conjunction with FIG. 1, it can be seen that the mounting bracket assembly 10 includes a bracket bar 30 which is designed to be mounted across the top opening of the flue 14. The bracket bar 30 is of a substantially integral construction, and includes a roller or pulley assembly 32 and a pair of oppositely positioned banding guides 34, 36. The bracket bar 30 further includes a pair of fixedly attached support plates 38, 40 and a chain guide member 42.
With respect to the construction of the roller or pulley assembly 32, it will be noted that the bracket bar 30 may be formed from a continuous metallic bar and may have a pair of substantially circular, spaced-apart metallic stops 44, 46 fixedly attached thereto. Prior to the attachment of the stops 44, 46 to the bar member 30, a short length of metallic conduit 48 is positioned therebetween whereby it is loosely supported by and movable relative to the bar member 30. Once the stops 44, 46 are fixedly secured in position, axial movement of the conduit 48 along the bar member 30 is prevented, while the conduit is freely rotatable about a section 50 of the bar member, as defined by the space between the stops 44, 46, inasmuch as no fixed securement of the conduit to the bar section 50 is effected. As such, the conduit 48 operates as a pulley and, as best shown in Figure 2, the large diameter of the conduit 48 relative to the diameter of the bar section 50 facilitates an erratic and transverse rotatable movement of the conduit in response to the uneven forces generated by the individual chain links of the chain 24. More specifically, it can be appreciated that a conventional pulley would have an internal diameter which would normally be only slightly greater than the diameter of the bar section 50 and which would normally then result in an erratic movement of the chain 24 over the pulley, since the individual chain link sections vary greatly in size. Through the use of the greater diameter conduit section 48, this erratic chain movement is translated to the conduit, i.e., the conduit pulley moves freely and erratically with respect to the bar section 50, so as to result in a more even and smooth movement of the chain 24.
Further illustrated in FIGS. 1, 2 and 3 is the aforementioned chain guide 42. The chain guide 42 may be of a semi-circular construction with its remote ends 52, 54 being fixedly secured to the bar section 50 on the opposed respective sides of the stops 44, 46. In this connection, any conventional attachment means, such as welding or the like, can be utilized to attach the chain guide to the bracket bar 30, while the same or different conventional attachment means can be utilized to fixedly secure the aforedescribed stops 44, 46 in position. While the stops 44, 46 would normally function to prevent a chain 24 from becoming disengaged from the roller assembly 32, the chain guide 42 is provided to further assure that a chain does not become disengaged from the pulley assembly. In effect, the chain guide 42, in combination with the stops 44, 46, defines an aperture through which the chain 24 may be directed and which absolutely prevents chain disengagement from the pulley assembly 32.
As best shown in FIGS. 1 and 3, the banding guides 34, 36 positioned at respective ends of the bracket bar 30 are of a U-shaped configuration and are designed to lie in juxtaposition to an external surface of the flue 14. When so positioned, the respective support plates 38, 40 will normally lie on a topmost portion of the flue 14 and of course, the rigid construction of the bracket bar 30 will require that it be predesigned and sized to fit the particular flue 14. As shown in FIGS. 1 and 4 then, once the banding guides 34, 36 are juxtaposed next to the flue structure 14 and the respective support plates 38, 40 lie in a supporting relationship on top of the flue, one or more strips of banding iron 56 may be directed through the banding guides in the illustrated manner. The banding iron 56 is designed to be tightly fitted about the flue 14 so as to firmly secure the mounting bracket assembly 10 in an operable position over the flue. As shown in FIGS. 3 and 5, the support plates 38, 40 are provided with respective through-extending apertures 58, 60. If desired, threaded fasteners 62 may be directed through the apertures 58, 60 to facilitate a further fixed securing of the bracket bar 30 to the chimney flue 14. Inasmuch as the flue 14 will normally be of a stone material construction, some type of special insert 64 may be prepositioned within the flue whereby the threaded fastener 62 may be securely fastened to the conventional insert.
FIGS. 1 and 2 further illustrate a novel connector assembly 66 which may be employed to connect the chain 24 to the cutter 12. In this regard, as discussed in the inventor's prior U.S. Pat. No. 4,409,703, the cutter 12 will normally have a fixedly attached cross-extending support bar 68. The metallic support bar 68 will be bent to form a loop 70 designed to facilitate an attachment of the chain 24 to the cutter 12. To facilitate this attachment, the connector assembly 66 may include a rectangularly-shaped plate member 72 having a metallic loop 74 fixedly secured to a topmost portion thereof. The metallic loop 74 in the preferred embodiment of the invention is attached to the plate 72 by a pair of rivets 76, 78 directed through the respective ends of the loop and through the plate. As best illustrated in FIG. 2 then, an end link 80 of the chain 24 may have the metallic loop 74 directed therethrough prior to a final riveting of the loop to the plate 72.
With further reference to FIGS. 1 and 2, the plate 72 is illustrated with a through-extending aperture 82 positioned under the loop member 74 and a piece of soft bar stock 84 may be directed upwardly through the aperture and flared at its end 86 so as to prevent its disengagement from the plate 72. The soft bar stock 84 may then have its remaining free end bent into a loop 88 with the support loop 70 passing therethrough. As such, the loop 88 is operably and fixedly secured to the support bar 68, thereby to connect the creosote cutter 12 to the chain 24.
A final noteworthy feature of the present invention is best illustrated in FIG. 1, wherein it can be seen that the bracket bar 30 extends upwardly above the topmost portion of the flue 14 in a manner whereby the pulley assembly 32 is substantially above the topmost portion of the chimney. The height of the pulley assembly 32 is carefully selected so that the creosote cutter 12 can be moved upwardly to a topmost portion of the flue 14 without the cutter being actually drawn completely out of the chimney. Two different safeguards are provided to prevent the creosote cutter 12 from coming out of the top of the flue 14. A first safeguard is formed by plate 72, as shown in FIG. 2, which, after the cutter 12 has been raised to its topmost position, will slide around the pulley assembly 32 and come into engagement with the stops 44, 46 and the chain guide 42. Once the plate 72 is in abutment thereagainst, no further movement of the cutter 12 upwardly within the flue can be undertaken. Operable in conjunction with this first safeguard, or independent therefrom, the bracket bar 30 is designed to gradually slope upwardly from its support plates 38, 40 to its roller assembly 32. This gradual upward slope of the bar 30 from its respective ends constitutes the second safeguard whereby the topmost cutting tooth section 18 of the cutter 12 will come into engagement with the sloping portions of the bracket bar prior to a total removal of the cutter from the chimney flue 14. In effect then, the cross-extending, upwardly-sloping sections of the bracket bar 30 serve as a stop against which the cutter 12 will come into abutment before it is drawn completely out of the chimney 16.
While the manner of operation of the present invention should now be apparent with reference to the above description, a brief summary thereof will be provided. In this respect, it can be seen that a user of the mounting bracket assembly 10 comprising the present invention need only to position the bracket bar 30 over the topmost portion of a chimney flue 14, as best shown in FIG. 1, and then attach a strip of banding iron 56 through the banding guides 34, 36 and around an exterior surface of the flue to effectively secure the bracket assembly in position. With the connector assembly 66 attached to a creosote cutter 12 contained within the flue 14, the support chain 24 may then be directed over the conduit section 48 through the chain guide 42 whereby an operator can then pull the chain from either interiorly or exteriorly of the chimney 16 so as to effect a desired up and down cleaning movement of the cutter 12 within the flue 14. In the event that the cutter 12 is drawn to its topmost position within the flue 14, the cutter may come into contact with the upwardly-sloping portions of the bracket bar 30 so as to be prevented from being drawn out of the flue, while the plate 72 may also effectively come into blocking contact with the chain guide 42 to prevent further upward movement of the cutter within the flue. A continual and even movement of the cutter 12 upwardly and downwardly within the flue 14 is effected by the use of the conduit 48 in place of a conventional pulley inasmuch as the conduit can move in multiple directions to compensate for the uneven and irregular conventional construction of the chain 24.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A mounting bracket assembly for a creosote cutter includes a mounting bracket which may be fixedly secured to a chimney so as to extend across the flue. Fastening bands wrapped around the chimney are directed through guides forming a part of the bracket, and a freely moving cylindrically-shaped section of conduit which functions as a pulley is centrally positioned on the bracket. A creosote cutter pull chain is positioned over the conduit and downwardly into the flue of the chimney. The pull chain both supports the cutter and operates as the means by which the cutter is selectively moved upwardly and downwardly within the flue. | 5 |
BACKGROUND OF THE INVENTION
The invention relates to a liquid jetting apparatus such as an ink jet recording apparatus, a display manufacturing apparatus, an electrode forming apparatus, a biochip manufacturing apparatus or the like, which can control ejection of liquid droplets from nozzle orifices by controlling supply of drive pulses to pressure generating elements in accordance with a jetting amount, as well as to a method for driving such an apparatus.
Various kinds of the liquid jetting apparatus have hitherto been known. For example, there have been known an image forming apparatus which records information on recording paper by jetting ink droplets, an electrode forming apparatus which forms an electrode on a board by jetting liquid-state electrode material, a biochip manufacturing apparatus which manufactures a biochip by jetting biological specimen, and a micropipette for jetting a predetermined amount of sample into a vessel.
A liquid jetting apparatus capable of changing the amount of liquid to be ejected from nozzle orifices with a view toward pursuing both higher-speed jetting operation and higher jetting amount accuracy has hitherto been known.
For example, an ink jet recording apparatus which is one kind of the liquid jetting apparatus has, for example, a recording head which has nozzle orifices communicating with a pressure chamber, and pressure generating elements capable of causing a change in the pressure of the ink stored in the pressure chamber; and a drive signal generator capable of producing a drive signal to be supplied to the pressure generating elements. The drive signal is a single signal formed by connecting a plurality of drive pulses into a string of pulses within one recording cycle. A required portion of the drive signal is supplied to the pressure generating element in accordance with recording data (i.e., gradation data), thereby changing the amount of ink to be ejected from a nozzle orifice. Such a configuration is disclosed in Japanese Patent Publication No. 10-81012A (see Page 9 and FIG. 9).
However, a related-art configuration in which a required portion of a single drive signal is supplied to pressure generating elements encounters difficulty in causing a jetting head (recording head) to sufficiently offer original performance thereof. More specifically, since a plurality of drive pulses are included in one jetting (recording cycle), there is no alternative but to actuate a jetting head (i.e., a pressure generating element) at a frequency lower than the maximum frequency at which the jetting head can be actuated.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a liquid jetting apparatus which can be constructed so as to be able to actuate a jetting head at a higher frequency, along with a method for driving such an apparatus.
In order to achieve the above object, according to the invention, there is provided a liquid jetting apparatus, comprising:
a jetting head, provided with a nozzle orifice, a pressure chamber communicated with the nozzle orifice, and a piezoelectric element which is deformable to cause pressure fluctuation to liquid contained in the pressure chamber;
a drive signal generator, which simultaneously generates a plurality of drive signals, each provided with waveform elements including at least one drive pulse in every unit recording cycle, the drive pulse deforming the piezoelectric element to cause such pressure fluctuation as to eject a liquid droplet from the nozzle orifice;
a switcher, which selectively supplies at least one of the waveform elements included in one of the drive signals to the piezoelectric element; and
a switch controller, which controls a selective supply operation of the switcher in accordance with amount data which indicates an amount of the liquid droplet to be ejected,
wherein a time period in which the drive pulse is generated in one of the drive signal and that in another one of the drive signals overlap at least partly.
In such a configuration, the recording cycle can be shortened as compared with that achieved when a plurality of drive pulses are included in one drive signal in the form of a single pulse train. As a result, a jetting head can be actuated at a higher frequency.
Preferably, the waveform elements in each drive signal include a drive waveform element which constitutes the drive pulse, and a constant-potential waveform element which maintains a potential of the drive signal at a leading-end potential and a trailing-end potential thereof.
Here, the switch controller may control the switcher such that the drive waveform element in one of the drive signals and the drive waveform element in another one of the drive signals are supplied to the piezoelectric element in the unit jetting cycle.
Alternatively, the switch controller may control the switcher such that the drive waveform element in one of the drive signals and the constant-potential waveform element in another one of the drive signals are supplied to the piezoelectric element in the unit jetting cycle.
Alternatively, the switch controller controls the switcher such that the constant-potential waveform element in at least one of the drive signals is supplied to the piezoelectric element in the unit jetting cycle.
Since the waveform elements of respective drive signals are supplied in combination to the pressure generating element within a jetting cycle by switch controller, a jetting head can be actuated in a new pattern which is not originally contained in respective drive signals. As a result, complicated control can be realized while the drive frequency of the jetting head is enhanced.
When the constant-potential waveform element is used, the piezoelectric element can be maintained at a constant potential. As a result, there can be prevented a drop in the potential of the piezoelectric element, which would otherwise be caused by an electric discharge. Thus, there can be prevented occurrence of failures, such as erroneous ejection of a liquid droplet.
Preferably, the switcher includes a plurality of switches interposed between the drive signal generator and the piezoelectric element such that each of the switches is associated with one of the drive signals.
Here, it is preferable that the switch controller selectively activates one of the switches such that one of the drive signals associated with an activated switch is supplied to the piezoelectric element.
Preferably, the switcher includes a plurality of input contacts each associated with one of the drive signals and an output contact electrically connected to the piezoelectric element. Here, the switch controller selectively connects one of the input contacts and the output contact such that one of the drive signals associated with a selected input contact is supplied to the piezoelectric element. In this case, the switching control can be simplified.
Preferably, the drive signals include: a first drive signal, in which at least two first drive pulses each for ejecting a first amount of liquid droplet are arranged at a predetermined interval; and a second drive signal, in which at least one second drive pulse for ejecting a second amount of liquid droplet is generated at a timing between timings at which the first drive pulses are generated. Here, the predetermined interval is determined such that the first drive pulses are still arranged at the predetermined interval even when the first drive signal is successively selected in adjacent unit jetting cycles.
In such a configuration, there can be prevented occurrence of an offset, which would otherwise arise in an interval between ejection of liquid droplets, thereby enabling an improvement in jetting amount accuracy.
Here, it is preferable that the first drive pulse including: an expanding element, in which a potential of the first drive signal is varied from a reference potential to a first potential at a constant gradient, so that a volume of the pressure chamber is expanded from a reference volume to a first volume; and first holding element, which maintains the volume of the pressure chamber at the first volume. On the other hand, the second drive pulse including: a second holding element, in which a potential of the second drive signal is maintained at the first potential to maintain the volume of the pressure chamber at the first volume; and a contracting element, in which the potential of the second drive signal is varied from the first potential to the reference potential at a constant gradient, so that the volume of the pressure chamber is contracted from the first volume to the reference volume. Here, the switch controller controls the switcher so as to supply the expanding element, the first holding element, the second holding element and the contracting element, to cause pressure fluctuation such an extent that no liquid droplet is ejected, when the amount data indicates no jetting is to be performed.
Further, it is preferable that; each of the first drive pulses is interposed between first constant-potential waveform elements which maintain a potential of the first drive signal at a reference potential so that an initial end and a termination end of each first drive pulse are set to the reference potential; the second drive pulse is interposed between second constant-potential waveform elements which maintain a potential of the second drive signal at the reference potential so that an initial end and a termination end of the second drive pulse are set to the reference potential; and the switch controller controls the switcher so as to supply one of the first drive pulses and one of the second constant-potential waveform element, so that a potential of the piezoelectric vibrator is set to the reference potential while the first drive pulse is not supplied, when the amount data indicates the first amount of liquid droplet to be ejected.
According to the invention, there is also provided a method of driving a liquid jetting apparatus which comprises a jetting head, provided with a nozzle orifice, a pressure chamber communicated with the nozzle orifice, and a piezoelectric element which is deformable to cause pressure fluctuation to liquid contained in the pressure chamber, the method comprising the steps of:
generating simultaneously a plurality of drive signals, each provided with waveform elements including at least one drive pulse in every unit jetting cycle, the drive pulse deforming the piezoelectric element to cause such pressure fluctuation as to eject a liquid droplet from the nozzle orifice;
providing a switcher which selectively supplies at least one of the waveform elements included in one of the drive signals to the piezoelectric element; and
controlling a selective supply operation of the switcher in accordance with amount data which indicates an amount of the liquid droplet to be ejected,
wherein a time period in which the drive pulse is generated in one of the drive signal and that in another one of the drive signals overlap at least partly.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:
FIG. 1 is a functional block diagram showing an ink jet recording apparatus according to a first embodiment of the invention;
FIG. 2 is a cross-sectional view showing the configuration of a recording head of longitudinal vibration mode;
FIG. 3 is a diagram for describing a drive signal to be generated by a drive signal generator and supply control of the drive signal;
FIG. 4 is a diagram for describing control of supply of the drive signal during non-recording operation;
FIG. 5 is a diagram for describing control of supply of a drive signal at the time of small dot recording operation;
FIG. 6 is a diagram for describing control of supply of a drive signal at the time of middle dot recording operation;
FIG. 7 is a diagram for describing control of supply of a drive signal at the time of large dot recording operation; and
FIG. 8 is a block diagram showing a switcher an ink jet recording apparatus according to a second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention will be described hereinbelow by reference to the accompanying drawings. The following explanations are for an ink jet recording apparatus which one kind of a liquid jetting apparatus. The ink jet recording apparatus jets ink droplets which is one kind of liquid droplets of the invention.
FIG. 1 shows a printer serving as an ink jet recording apparatus according to a first embodiment of the invention. The printer comprises a printer controller 1 and a print engine 2 . The printer controller 1 has an external interface 3 for receiving print data or the like from an unillustrated host computer or the like; a RAM 4 for storing a variety of data sets; a ROM 5 for storing routines for use in processing a variety of data sets; a controller 6 provided as a CPU or the like; an oscillator 7 for generating a clock (CK) signal; a drive signal generator 9 for generating drive signals (COM 1 , COM 2 ) to be supplied to a recording head; and an internal interface 10 for transmitting recording data, drive signals, or the like to the print engine 2 .
The external interface 3 receives, from a host computer, print data consisting of one type of data or a plurality of types of data selected from, e.g., a character code, a graphic function, and image data. The external interface 3 outputs a busy (BUSY) signal and an acknowledgement (ACK) signal to the host computer.
The RAM 4 is utilized as a receiving buffer, an intermediate buffer, an output buffer, work memory (not shown), and the like. Print data that have been output from the host computer and received by the external interface 3 are temporarily stored in a receiving buffer. Intermediate code data that have been converted into an intermediate code by the controller 6 are stored in an intermediate buffer. Data to be recorded (hereinafter called “recording data”) are expanded into an output buffer. The ROM 5 stores various control routines, font data, graphics functions, and various procedures.
The drive signal generator 9 comprises a first drive signal generating section 9 A capable of generating a first drive signal COM 1 and a second drive signal generating section 9 B capable of generating a second drive signal COM 2 . As shown in FIG. 3, the first drive signal COM 1 is a signal train which includes two middle dot drive pulses DP 1 , DP 2 within one recording cycle T and is generated at every recording cycle T. The second drive signal COM 2 is a signal train which includes a small-dot drive pulse DP 3 within one recording cycle T and is generated at every recording cycle T. The second rive signal COM 2 is repeatedly generated at every recording cycle T. The drive signals COM 1 , COM 2 will be described in detail later.
The controller 6 controls generation of a signal to be sent to the drive signal generator 9 and converts the print data output from the host computer into recording data. At the time of conversion of print data into recording data, the controller 6 reads print data from the inside of the receiving buffer, converts the thus-read print data into an intermediate code, and stores intermediate code data into an intermediate buffer. Next, the controller 6 analyzes the intermediate code data read from the intermediate buffer and converts the intermediate code data into recording data on a per-dot basis by reference to the font data and the graphics functions stored in the ROM 5 .
The recording data of the embodiment is constituted such that one bit is formed from two-bit gradation data. The gradation data comprise gradation data [ 00 ] indicating a non-recording state (meniscus vibrating operation); gradation data [ 01 ] indicating recording to be performed through use of small dots; gradation data [ 10 ] indicating recording to be performed through use of middle dots; and gradation data [ 11 ] indicating recording to be performed through use of large dots. Accordingly, such a data structure enables recording of each dot in four levels of tone.
The controller 6 constitutes a part of a timing signal generator and supplies a latch (LAT) signal and channel (CH-A, CH-B) signals to the recording head 8 by way of the internal interface 10 . Latch pulses included in the latch signal and channel pulses included in the channel signals define start timings of supply of a plurality of waveform elements constituting the drive signals COM 1 , COM 2 and supply of adjustment elements (PS 1 to PS 6 , and P 0 , P 20 ).
Specifically, as shown in FIG. 3, a latch pulse LAT 1 defines a start timing of supply of an adjustment element P 0 to be generated during a charging period t 10 and a start timing of supply of an adjustment element P 20 to be generated during a charging period t 20 .
A first channel pulse CH 11 appearing in a first channel signal CH-A defines a start timing of supply of a first waveform section PS 1 to be generated during a period t 11 of the first drive signal COM 1 . A second channel pulse CH 12 defines a start timing of supply of a second waveform section PS 2 to be generated during a period t 12 . A third channel pulse CH 13 defines a start timing of supply of a third waveform section PS 3 to be generated during a period t 13 .
Similarly, a first channel pulse CH 21 appearing in a second channel signal CH-B defines a start timing of supply of a fourth waveform section PS 4 to be generated during a period t 21 of the second drive signal COM 2 . A second channel pulse CH 22 defines a start timing of supply of a fifth waveform section PS 5 to be generated during a period t 22 . A third channel pulse CH 23 defines a start timing of supply of a sixth waveform section PS 6 to be generated during a period t 23 .
The print engine 2 will now be described. As shown in FIG. 1, the print engine 2 has a recording head 8 , a carriage mechanism 11 , and a paper feeding mechanism 12 .
The carriage mechanism 11 is constituted of a carriage having the recording head 8 mounted thereon, and a drive motor (e.g., a DC motor) which causes to the carriage to travel by way of a timing belt or the like. The carriage mechanism 11 moves the recording head 8 in the primary scanning direction. The paper feeding mechanism 12 is constituted of a paper feeding motor and a paper feeding roller and like rollers. The paper feeding mechanism 12 performs secondary scanning by sequentially feeding recording paper (i.e., a kind of print recording medium).
The recording head 8 will now be described in detail. First, the structure of the recording head 8 will be described by reference to FIG. 2 . The illustrated recording head 8 has a vibrator unit 24 into which a plurality of piezoelectric vibrators 21 a fixation plate 22 , and a flexible cable 23 are assembled as a unit; a case 25 capable of housing the vibrator unit 24 ; and a channel unit 26 joined to a leading end face of the case 25 .
The case 25 is a block-shaped member which is formed from synthetic resin and defines a housing space 27 whose front and rear ends are open. The vibrator unit 24 is housed and fixed in the housing space 27 .
The piezoelectric vibrator 21 is a kind of pressure generating element and formed into a longitudinally-elongated comb shape. The piezoelectric vibrator 21 is a piezoelectric vibrator of lamination type formed by laminating piezoelectric material layers and internal electrodes one on top of the other. The piezoelectric vibrator 21 is of longitudinal vibration mode, in which the vibrator can swell and shrink in a longitudinal direction orthogonal to the direction in which the piezoelectric material layers are laminated. Leading-end faces of the respective piezoelectric vibrators 21 are joined to an island portion 28 of the channel unit 26 .
The piezoelectric vibrator unit 21 acts in the same way as does a capacitor. Specifically, when supply of a signal is stopped, the potential of the piezoelectric vibrator 21 (i.e., the potential of the vibrator) is held at a potential attained immediately before supply of the signal is stopped.
The channel unit 26 is constituted by sandwiching a channel forming substrate 29 between a nozzle plate 30 and an elastic plate 31 , which oppose each other.
The nozzle plate 30 is formed from a thin metal plate material (e.g., a stainless steel plate) having a plurality of nozzle orifices 32 (e.g., 96 nozzle orifices) provided in a secondary scanning direction. The channel forming substrate 29 is a plate-shaped member in which an ink flow passage is defined by a common ink reservoir 33 , an ink supply port 34 , a pressure chamber 35 , and a communication port 36 . In the embodiment, the, channel forming substrate 29 is made of a silicon wafer by etching. The elastic plate 31 is a composite plate material of a dual structure and formed by laminating a stainless steel support plate 37 with a resin film 38 . The island portion 28 is formed by annually removing a portion of the support plate 37 opposing the pressure chamber 35 .
In the recording head 8 , a string of ink flow passages are defined for each nozzle orifice 32 so as to extend from the common ink reservoir 33 to a corresponding nozzle orifice 32 by way of the pressure chamber 35 . The piezoelectric vibrator 21 is deformed as a result of being subjected to discharging and charging. Specifically, the piezoelectric vibrator 21 of longitudinal vibration mode contracts in a longitudinal direction thereof when subjected to recharge and extends in the same direction when subjected to discharge. When the potential of the vibrator is increased as a result of a charging operation, the island portion 28 is pulled toward the piezoelectric vibrator, whereby the resin film 38 located around the island portion 28 is deformed and the pressure chamber 35 expands. In contrast, when the potential of the vibrator is lowered as a result of a discharging operation, the pressure chamber 35 contracts.
In this way, the volume of the pressure chamber 35 can be controlled in accordance with the potential of the vibrator, and hence the pressure of the ink stored in the pressure chamber 35 can be changed, thereby ejecting an ink droplet from the nozzle orifice 32 . For instance, the pressure chamber 35 having a reference volume is caused to abruptly shrink after having been expanded, thereby enabling ejection of an ink droplet.
An electrical configuration of the recording head 8 will now be described.
As shown in FIG. 1, the recording head 8 has a shift register circuit constituted of a first shift register 41 and a second shift register 42 ; a latch circuit constituted of a first latch 43 and a second latch 44 ; a level shifter circuit constituted of a decoder 45 , a control logic 46 , a first level shifter 47 , and a second level shifter 48 ; a switching circuit constituted of a first switcher 49 and a second switcher 50 ; and the piezoelectric vibrators 21 .
A plurality of shift registers 41 , 42 ; a plurality of latches 43 , 44 ; a plurality of level shifters 47 , 48 ; a plurality of switchers 49 , 50 ; and a plurality of piezoelectric vibrators 21 are provided so as to correspond to the respective nozzle orifices 32 .
In accordance with the recording data (SI) output from the printer controller 1 , the recording head 8 ejects ink droplets. In the embodiment, a group of higher order bits of recording data and a group of lower order bits of recording data are sent to the recording head 8 , in this sequence. Hence, the group of higher order bits of recording data are first set in the second shift register 42 . When the group of higher order bits of recording data have been set in the second shift register 42 with regard to all the nozzle orifices 32 , the group of lower order bits of recording data are subsequently set in the second shift register 42 . In association with setting of the group of lower order bits of recording data, the group of higher order bits of recording data are shifted and set to the first shift register 41 .
The first latch 43 is electrically connected to the first shift register 41 . The second latch 44 is electrically connected to the second shift register 42 . When a latch pulse (LAT 1 ) output from the printer controller 1 is input to the respective latch circuits 43 , 44 , the first latch 43 latches the group of higher order bits of recording data, and the second latch 44 latches the group of lower order bits of recording data.
The recording data (i.e., the group of higher order bits and the group of lower order bits) latched by the latch circuits 43 , 44 are respectively input to the decoder 45 The decoder 45 performs translating operation on the basis of the higher order bits and lower order bits of recording data, thereby producing waveform selection data to be used for selecting the waveform elements PS 1 to PS 6 and the adjustment elements P 0 , P 20 , which constitute the drive signals COM 1 , COM 2 .
In the embodiment, the waveform selection data are generated for each of the drive signals COM 1 , COM 2 . Specifically, first waveform selection data corresponding to the first drive signal COM 1 are formed from a total of four bits of data; that is, the bits being assigned respectively to a first adjustment element P 0 (a period t 10 ), a first waveform section PS 1 (a period t 11 ), a second waveform section PS 2 (a period t 12 ), and a third waveform section PS 3 (a period t 13 ). Second waveform selection data corresponding to the second drive signal COM 2 are formed from a total of four bits of data; that is, the bits being assigned respectively to a second adjustment element P 20 (a period t 20 ), a fourth waveform section P 54 (a period t 21 ), a fifth waveform section PS 5 (a period t 22 ), and a sixth waveform section PS 6 (a period t 23 ).
The decoder 45 serves as a waveform selection data generator and generates a plurality of sets of waveform selection data from the recording data (i.e., gradation data), the data being equal in number to drive signals.
A timing signal output from the control logic 46 is also input to the decoder 45 . The control logic 46 serves as the timing signal generator along with the controller 6 . In synchronism with input of a latch signal (LAT) and channel signals (CH-A, CH-B), timing signals (TYM-A, TYM-B) are generated.
The timing signal is also generated for each of the drive signals COM 1 , COM 2 . Specifically, the control logic 46 generates the first timing signal (TYM-A) from the latch pulse (LAT 1 ) and channel pulses (CH 11 to CH 13 ) for the first drive signal COM 1 . Further, the control logic 46 generates the second timing signal (TYM-B) from the latch pulse and channel pulses (CH 21 to CH 23 ) for the second drive signal COM 2 .
The four bits of waveform selection data generated by the decoder 45 are input to the respective level shifters 47 , 48 in descending order from the high order bits at a timing specified by the timing signal. In accordance with timings at which respective timing pulses included in the first timing signal TYM-A are to be generated, the first waveform selection data are input to the first level shifter 47 . Moreover, in accordance with timings at which respective timing pulses included in the second timing signal TYM-B are to be generated, the second waveform selection data are input to the second level shifter 48 .
The level shifters 47 , 48 serves as voltage amplifiers. In a case where the waveform selection data assume a value of [1], the level shifters 47 , 48 output an electric signal which has been boosted up to a voltage at which corresponding switchers 49 , 50 can be activated; for example, approximately tens of volts. More specifically, when the first waveform selection data assume a value of [1], an electric signal is output to the first switcher 49 . When the second waveform selection data assume a value of [1], an electric signal is output to the second switcher 50 .
The first drive signal COM 1 is supplied to an input side of the first switcher 49 from the drive signal generator 9 . The second drive signal COM 2 is supplied to an input side of the second switcher 50 from the same. Further, the piezoelectric vibrator 21 is electrically connected to output sides of the switchers 49 , 50 . The switchers 49 , 50 are provided in accordance with the type of a drive signal to be generated. The switchers 49 , 50 are interposed between the drive signal generator 9 and the piezoelectric vibrator 21 and selectively supply the drive signals COM 1 , COM 2 to the piezoelectric vibrator 21 .
The waveform selection data are used to control operation of the switcher 49 and that of the switcher 50 . During a period in which the waveform selection data input to the first switcher 49 assumes a value of [1], the first switcher 49 is brought into conduction, and the first drive signal COM 1 is supplied to the piezoelectric vibrator 21 . Similarly, during a period in which the waveform selection data input to the second switcher 50 assumes a value of [1], the second switcher 50 is brought into conduction, and the first drive signal COM 1 is supplied to the piezoelectric vibrator 21 . In response to the thus-supplied drive signals COM 1 , COM 2 , a potential of the piezoelectric vibrator 21 is changed. During a period in which the waveform selection data input to the switcher 49 and those input to the switcher 50 assume a value of [ 0 ], an electric signal to be used for activating the switchers 49 , 50 is output from neither the level shifter 47 nor the level shifter 48 . Hence, a drive signal is not supplied to the piezoelectric vibrator 21 . In other words, the adjustment elements P 0 , P 20 and the waveform elements (i.e., the first waveform section PS 1 through the sixth waveform section PS 6 ), which have arisen during a period in which a value of [1] is set as waveform selection data, are selectively supplied to the piezoelectric vibrator 21 .
In the embodiment, the decoder 45 , the control logic 46 , and the level shifters 47 , 48 serve as a switch controller. The switchers 49 , 50 are controlled in accordance with recording data (i.e., gradation data).
The drive signals COM 1 , COM 2 generated by the drive signal generator 9 will now be described, along with control of supply of the drive signals COM 1 , COM 2 to the piezoelectric vibrator 21 .
As mentioned above, the drive signals shown in FIG. 3 are embodied as the first drive signal COM 1 and the second drive signal COM 2 . The first drive signal COM 1 comprises a first adjustment element P 0 generated during the period t 10 ; a first waveform section PS 1 generated during the period t 11 ; a second waveform section PS 2 generated during the period t 12 ; and a third waveform section PS 3 generated during the period t 13 . The second drive signal COM 2 comprises a second adjustment element P 20 generated during the period t 20 ; a fourth waveform section PS 4 generated during the period t 21 ; a fifth waveform section PS 5 generated during the period t 22 ; and a sixth waveform section PS 6 generated during the period t 23 .
The first drive signal COM 1 will first be described.
The first adjustment element P 0 is formed from a waveform element which is uniform at an intermediate potential Vhm. As will be described later, the first adjustment element P 0 is supplied to the piezoelectric vibrator 21 so as to adjust the potential of the vibrator to the intermediate potential Vhm at the beginning of the recording cycle T.
Here, the intermediate potential Vhm is a kind of reference potential and also serves as leading-edge and trailing-edge potentials of the respective drive pulses DP 1 through PD 3 .
The first waveform section PS 1 is formed from a first constant potential element P 1 , a first expanding element P 2 , and a first expansion holding element P 3 . The first constant potential element P 1 is a waveform element which is constant at an intermediate potential Vhm. The first expanding element P 2 is a waveform element for causing a potential to increase from the intermediate potential Vhm to a first expansion potential Vh 1 at such a relatively gentle-constant gradient that no ink droplets are ejected. The first expansion holding element P 3 is a waveform element which is constant at the first expansion potential Vh 1 .
The second waveform section PS 2 is formed from a second expansion holding element P 4 , a first ejection element P 6 , a contraction holding element P 6 , a damping element P 7 , and a second constant potential element P 8 . The second expansion holding element P 4 is a waveform element which is constant at the first expansion potential Vh 1 . The first ejection element P 5 is a waveform element for causing a potential to drop from the first expansion potential Vh 1 to a contraction potential VL at a relatively steep gradient. The contraction holding element P 6 is a waveform element which is constant at the contraction potential VL. The damping element P 7 is a waveform element for causing a potential to increase from the contraction potential VL to the intermediate potential Vhm at such a relatively gentle constant gradient that no ink droplets are ejected. Moreover, the second constant potential element P 8 is a waveform element which is constant at the intermediate potential Vhm.
The third waveform section PS 3 is formed from a third constant potential element P 9 , a first expanding element P 10 , an expansion holding element P 11 , a first ejection element P 12 , a contraction holding element P 13 , and a damping element P 14 .
The third constant potential element P 9 is a waveform element which is constant at the intermediate potential Vhm. The expansion holding element P 11 is a waveform element which is constant at the first expansion potential Vh 1 . A period of time during which the expansion holding element P 11 is generated is set to a value equal to the sum of the duration of the first expansion holding element P 3 and the duration of the second expansion holding element P 4 .
The remaining waveform elements; that is, the first expanding element P 10 , the first ejection element P 12 , the contraction holding element P 13 , and the damping element P 14 , are identical with the first expanding element P 2 , the first ejection element P 5 , the contraction holding element P 6 , and the damping element P 7 , all belonging to the first and second waveform elements PS 1 , PS 2 , and hence their repeated explanations are omitted.
In relation to the first drive signal COM 1 , the first expanding element P 2 , the first expansion holding element P 3 , the second expansion holding element P 4 , the first ejection element P 5 , the contraction holding element P 6 , and the damping element P 7 , all belonging to the first and second waveform elements PS 1 , PS 2 , constitute the first middle dot drive pulse DP 1 . Moreover, the first expanding element P 10 , the expansion holding element P 11 , the first ejection element P 12 , the contraction holding element P 13 , and the damping element P 14 , all belonging to the third waveform section PS 3 , constitute the second middle dot drive pulse DP 2 . The middle dot drive pulses DP 1 , DP 2 assume identical waveform patterns. When the middle dot drive pulses DP 1 , DP 2 are supplied to the piezoelectric vibrator 21 , the amount of ink corresponding to a middle dot is ejected from a corresponding nozzle orifice 32 .
Descriptions are now given by taking the first middle dot drive pulse DP 1 as an example. As a result of supply of the first expanding element P 2 , the piezoelectric vibrator 21 contracts in a longitudinal direction thereof. In contract, a corresponding pressure chamber 35 expands from a reference volume corresponding to the intermediate potential Vhm (reference potential) to an expanded volume corresponding to a first expansion potential Vh 1 . By the expanding action of the pressure chamber 35 , ink is supplied from the common ink reservoir 33 to the inside of the pressure chamber 35 . The expanded state of the pressure chamber 35 is maintained during a period in which the first and second expansion holding elements P 3 and P 4 are supplied.
Subsequently, the first ejection element P 5 is supplied to the piezoelectric vibrator 21 , whereby the piezoelectric vibrator 21 is extended. In association with extension of the piezoelectric vibrator 21 , the pressure chamber 35 is abruptly contracted from the expanded volume to a contracted volume corresponding to the contraction potential VL. The ink stored in the pressure chamber 35 is compressed as a result of abrupt contraction of the pressure chamber 35 , whereby a predetermined quantity of ink is ejected from a corresponding nozzle orifice 32 .
The contracted state of the pressure chamber 35 is maintained over a period during which the contraction holding element P 6 is supplied. During this period, the pressure of the ink stored in the pressure chamber 35 , the pressure having dropped by ejection of an ink droplet, is again increased by the natural vibration of ink. The damping element P 7 is supplied in step with the timing at which the pressure increases. As a result of supply of the damping element P 7 , the pressure chamber 35 expands and is restored to the reference volume, thereby absorbing changes in the pressure of the ink stored in the pressure chamber 35 .
In relation to the first drive signal COM 1 , the first middle dot drive pulse DP 1 and the second middle dot drive pulse DP 2 are connected together at the leading edge and trailing-edge potentials thereof (i.e., the intermediate potential Vhm), by the first adjustment element P 0 , the first constant potential element P 1 , the second constant potential element P 8 , and the third constant potential element P 9 . Thus, the middle dot drive pulses DP 1 , DP 2 are generated at given intervals over adjacent recording cycles T. Specifically, the sum of a period of time during which the first adjustment element P 0 is generated and a period of time during which the first constant potential element P 1 is generated is set to a value identical with that of the sum of a period of time during which the second constant potential element P 8 is generated and a period of time during which the third constant potential element P 9 is generated.
Given that the middle dot drive pulses DP 1 , DP 2 are generated at given intervals over adjacent recording cycles T, when the medium drive pulses DP 1 , DP 2 are continuously supplied to the piezoelectric vibrator 21 , the status of a meniscus achieved at the beginning of supply of the drive pulses can be maintained constant. As a result, the flight of an ink droplet can be stabilized, thereby realizing an attempt to improve image quality.
In relation to the first drive signal COM 1 having the foregoing configuration, the first expanding elements P 2 , P 10 , the first expansion holding element P 3 , the second expansion holding element P 4 , the expansion holding element P 11 , the first ejection elements P 5 , P 12 , the contraction holding elements P 6 , P 13 , and the damping elements P 7 , P 14 , serve as drive waveform elements.
On the other hand, the first adjustment element P 0 , the first constant potential element P 1 , the second constant potential element P 8 , and the third constant potential element P 9 , serve as constant-potential waveform elements.
The second drive signal COM 2 will now be described.
The second adjustment element P 20 is formed from a waveform element which is constant at the intermediate voltage Vhm, in the same manner as is the first adjustment element P 0 . In order to adjust the potential of the vibrator to the intermediate potential Vhm at the beginning of the recording cycle T, the second adjustment element P 20 is also supplied to the piezoelectric vibrator 21 .
In the embodiment, either the second adjustment element P 20 or the first adjustment element P 0 is supplied to the piezoelectric vibrator 21 at the beginning of the recording cycle T. Hence, a period t 20 of time during which the second adjustment element P 20 is generated is set to become identical in duration with a period t 10 of time during which the first adjustment element P 0 is generated.
The fourth waveform section PS 4 is formed from a fourth constant potential element P 21 . The fourth potential element P 21 is a waveform element which is constant at the intermediate potential Vhm and is generated at a point in time between the period t 11 and the period t 12 of the first drive signal COM 1 . Specifically, generation of the waveform element is commenced at the start of the period t 11 and terminated at an intermediate point during a period of time in which the contraction holding element P 6 of the second waveform section PS 2 is generated.
The fifth waveform section PS 5 is formed from a fifth constant potential element P 22 , a second expanding element P 23 , an expansion holding element P 24 , a second ejection element P 25 , and a first contraction holding element P 26 . The fifth potential element P 22 is a waveform element which is constant at the intermediate potential Vhm and is generated over an extremely short period of time. The second expanding element P 23 is a waveform element which causes a potential to abruptly increase from the intermediate potential Vhm to a second expansion potential Vh 2 . The expansion holding element P 24 is a waveform element which is constant at the second expansion potential Vh 2 . The second ejection element P 25 is a waveform element which causes a potential to abruptly drop from the second expansion potential Vh 2 to an ejection potential Vh 3 . The first contraction holding element P 26 is a waveform element which is constant at the ejection potential Vh 3 .
The ejection potential Vh 3 of the embodiment is made equal to the first expansion potential Vh 1 of the first drive signal COM 1 .
The sixth waveform section PS 6 is formed from a second contraction holding element P 27 , a damping element P 28 , and a sixth constant potential element P 29 . The second contraction holding element P 27 is a waveform element which is constant at the ejection potential Vh 3 and is generated over an extremely short period of time. The damping element P 28 is a waveform element for causing a potential to drop from the ejection potential Vh 3 to the intermediate potential Vhm at a relatively gentle, constant gradient. The sixth constant potential element P 29 is a waveform element which is constant at the intermediate potential Vhm and is generated from the trailing edge of the damping element P 28 to the trailing edge of the recording cycle T.
In relation to the second drive signal COM 2 , the second expanding element P 23 , the expansion holding element P 24 , the second ejection element P 25 , the contraction holding elements P 26 , P 27 , and the damping element P 28 , all belonging to the fifth and sixth waveform elements PS 5 , PS 6 , constitute the small dot drive pulse DP 3 When the small dot drive pulse DP 3 is supplied to the piezoelectric vibrator 21 , a nominal amount of ink corresponding to a small dot is ejected from the nozzle orifice 32 .
Specifically, as a result of supply of the second expanding element P 23 , the piezoelectric vibrator 21 rapidly contracts in the longitudinal direction thereof. The pressure chamber 35 rapidly expands from the reference volume corresponding to the intermediate potential Vhm to an expanded volume corresponding to the second expansion potential Vh 2 . As a result of expansion, relatively high negative pressure develops in the pressure chamber 35 , thereby strongly drawing a meniscus (i.e., an exposed free surface of ink in the nozzle orifice 32 ) toward the pressure chamber 35 . The expanded state of the pressure chamber 35 is held over a period during which the expansion holding element P 24 is supplied. During this period, the moving direction of a center portion of the meniscus is reversed to the direction in which ink is to be ejected. The center portion becomes raised in the form of a pillar.
Subsequently, the second ejection element P 25 is supplied to the piezoelectric vibrator 21 , whereupon the vibrator extends. As a result of extension of the piezoelectric vibrator 21 , the pressure chamber 35 is abruptly contracted from the expanded volume to an ejection volume corresponding to the second expansion potential Vh 3 . By abrupt contraction of the pressure chamber 35 , the ink stored in the pressure chamber 35 is compressed, thereby promoting growth of the pillar portion. The pillar portion is broken at an intermediate position thereof, whereby ink is ejected in the form of an ink droplet.
The second ejection element P 25 is followed by supply of the first contraction holding element P 26 and supply of the second contraction holding element P 27 Subsequently, the damping element P 28 is supplied. The damping element P 28 contracts the pressure chamber 35 so as to compensate for the drop in pressure of the ink stored in the pressure chamber 35 resulting from ejection of an ink droplet. Specifically, the pressure chamber 35 is contracted to a reference volume by supply of the damping element P 28 , thereby absorbing a change in the pressure of the ink stored in the pressure chamber 35 .
A period of time during which the respective waveform elements (P 23 through P 28 ) constituting the small dot drive pulse DP 3 are to be generated partially overlaps periods of time during which the respective waveform elements (P 2 to P 7 , P 10 to P 14 ) constituting the middle dot drive pulse DP 1 , DP 2 are to be generated. Specifically, a period of time during which the second expanding element P 23 of the small dot drive pulse DP 3 is generated partially overlaps a period of time during which the damping element P 7 of the first middle dot drive pulse DP 1 is to be generated. Further, a period of time during which the damping element P 28 of the small dot drive pulse DP 3 is to be generated overlaps, at the trailing edge, a period of time during which the first expanding element P 10 of the second middle dot drive pulse DP 2 is to be generated.
In this way, the drive pulses DP 1 to DP 3 are divided into the drive signals COM 1 , COM 2 and generated so as to be superimposed on each other with respect to time. In this case, the drive pulses DP 1 through DP 3 and the first vibrating pulse VP 1 can be efficiently arranged in even a recording cycle T of limited length. Consequently, high-frequency driving of the recording head 8 can be realized.
In relation to the second drive signal COM 2 , the small dot drive pulses DP 3 are connected together at the leading-edge and trailing-edge potentials thereof (i.e., the intermediate potential Vhm), by the second adjustment element P 20 , the fourth constant potential element P 21 , the fifth constant potential element P 22 , and the sixth constant potential element P 29 .
A timing at which the small dot drive pulse DP 3 is to be generated is set to an intermediate point in time between the first middle dot drive pulse DP 1 and the second middle dot drive pulse DP 2 . In detail, a timing at which the second ejection element P 25 of the small middle dot drive pulse DP 3 is to be generated is set to an exactly intermediate point in time between a timing at which the first ejection element P 5 of the first middle dot drive pulse DP 1 is to be generated and a timing at which the first ejection element P 12 of the second middle dot drive pulse DP 2 is to be generated, in an attempt to improve image quality.
As will be described later, in the embodiment, the first middle dot drive pulse DP 1 and the second middle dot drive pulse DP 2 are supplied to the piezoelectric vibrator 21 at the time of recording of a large dot, and the second middle dot drive pulse DP 2 is supplied to the piezoelectric vibrator 21 at the time of recording of a middle dot. Further, at the time of recording of a small dot, the small dot drive pulse DP 3 is supplied to the piezoelectric vibrator 21 .
Here, if the small dot drive pulse DP 3 is generated at an intermediate point in time between the first middle dot drive pulse DP 1 and the second middle dot drive pulse DP 2 , an interval between ejection of an ink droplet and ejection of the next ink droplet can be made uniform even when a recording gradation is changed between a preceding recording cycle T and a current recording cycle T. For instance, an interval between ejection of ink for producing a small dot during a preceding recording cycle T and ejection of ink for producing a large dot during a current recording cycle T can be made equal to that existing between ejection of ink for producing a large dot during a preceding recording cycle T and ejection of ink for producing a small dot during the current recording cycle T.
As a result, the status of a meniscus generated during a current recording cycle T becomes uniform, and ejection of an ink droplet can stabilized, and by extension image quality can be improved.
In relation to the second drive signal COM 2 having the foregoing configuration, the second expanding element P 23 , the expansion holding element P 24 , the second ejection element P 25 , the first contraction holding element P 26 , the second contraction holding element P 27 , and the shrinking damping element P 28 , serve as drive waveform elements. On the other hand, the second adjustment element P 20 , the fourth constant potential element P 21 , the fifth constant, potential element P 22 , and the sixth constant potential element P 29 , serve as constant-potential waveform elements.
Control of multiple gradations to be performed in the embodiment will now be described by reference to FIGS. 3 through 7. During control of multiple gradations, the switchers 49 , 50 are controlled by the switch controller (embodied by a combination of the decoder 45 , the control logic 46 , and the level shifters 47 , 48 ; the same also applies to any counterparts in the following descriptions). The respective switchers 49 , 50 supply the selected drive signals COM 1 , COM 2 to the piezoelectric vibrator 21 . Specifically, the first drive signal COM 1 and the second drive signal COM 2 are not simultaneously supplied to the piezoelectric vibrator 21 , in order to stabilize the potential of the vibrator 21 .
An explanation will first be given of the case of non-recording operation (meniscus vibration). In this case, the decoder 45 generates the first waveform selection data [ 1100 ] and the second waveform selection data [ 0001 ] by translation of gradation data [ 00 ] for non-recording operation. The switch controller controls operation of the first switcher 49 and that of the second switcher 50 on the basis of the thus-generated waveform selection data, which in turn controls supply of the first drive signal COM 1 and the second drive signal COM 2 to the piezoelectric vibrator 21 .
During the period t 10 (t 20 ), the first adjustment element P 10 is supplied to the piezoelectric vibrator 21 . As a result, the potential of the vibrator is adjusted to the intermediate potential Vhm. Here, one is selected from the first adjustment element P 0 and the second adjustment element P 20 in accordance with the next waveform element (i.e., waveform element) to be sent, and the selected element is supplied to the piezoelectric vibrator 21 . Specifically, if the next waveform element to be supplied is a waveform element of the first drive signal COM 1 , the fist adjustment element P 0 is selected. If the next waveform element to be supplied is a waveform element of the second drive signal COM 2 , the second adjustment element P 20 is selected. Such a selecting operation is performed in order to reduce the number of times the switchers 49 , 50 operate. More specifically, if the number of times the switchers 49 , 50 operate is reduced, a drive signal supplied to the piezoelectric vibrator 21 is stabilized, in turn stabilizing operation of the piezoelectric vibrator 21 .
During the period t 11 , the first switcher 49 is brought into a connected state. During the period t 21 , the second switcher 50 is brought into a disconnected state. Specifically, as indicated by a bold line shown in FIG. 4, the first waveform section PS 1 of the first drive signal COM 1 is supplied to the piezoelectric vibrator 21 . The pressure chamber 35 is expanded to an expanded volume by the first expanding element P 2 . In association with swelling of the pressure chamber 35 , the ink stored in the pressure chamber 35 is slightly decompressed.
During subsequent periods t 12 and t 13 , the first switcher 49 is controlled and brought into a disconnected state, and the second switcher 50 is controlled and brought into a disconnected state during a period t 22 . As a result, neither the first drive signal COM 1 nor the second drive signal COM 2 is supplied to the piezoelectric vibrator 21 from the beginning of the period t 12 to the end of the period t 22 . Consequently, as indicated by a semi-bold line shown in FIG. 4, the potential of the vibrator is maintained at the first expansion potential Vh 1 which appears immediately before disconnection of the first switch, and the expanded volume of the pressure chamber 35 is maintained. During the period, pressure fluctuations in the ink stored in the pressure chamber 35 are induced by the depressurization that has arisen during the period t 11 .
During a period t 23 , the second switcher 50 is controlled and brought into a connected state. As a result, as indicated by a bold line shown in FIG. 4, a sixth waveform section PS 6 of the second drive signal COM 2 is supplied to the piezoelectric vibrator 21 , whereby the pressure chamber 35 is contracted to the reference volume by the damping element P 28 . In association with contraction of the pressure chamber 35 , the ink stored in the pressure chamber 35 is slightly compressed.
By pressure fluctuations imparted to ink, a meniscus is minutely vibrated toward the pressure chamber 35 as well as in a direction in which an ink droplet is to be ejected. By the minute vibration of the meniscus, the ink that is located in the vicinity of the nozzle orifice 32 and whose viscosity is increased is dispersed, thereby preventing an increase in the viscosity of ink.
In the embodiment, the first expansion potential Vh 1 of the first drive signal COM 1 and the ejection potential Vh 2 of the second drive signal COM 2 are set so as to assume the same potential. Hence, when the sixth waveform section PS 6 (i.e., a second contraction holding element P 27 ) is supplied to the piezoelectric vibrator 21 during the period t 23 , the potential of the vibrator and the leading-edge potential of the sixth waveform section PS 6 are made equal to each other. Hence, the sixth waveform section PS 6 can be smoothly supplied to the piezoelectric vibrator 21 .
In the embodiment, in the case of a recording gradation for non-recording, portions of the waveform elements constituting the first drive signal COM 1 (i.e., the first expanding element P 2 and the first expansion holding element P 3 ) and a portion of the waveform element constituting the second drive signal COM 2 (i.e., the second contraction holding element P 27 and the damping element P 28 ) are supplied, in combination, to the piezoelectric vibrator 21 , thereby minutely vibrating a meniscus. As a result, the meniscus can be vibrated minutely without provision in the respective drive signals COM 1 , COM 2 of the waveform elements specifically designed for minute vibration, thereby preventing an increase in the viscosity of the ink located in the vicinity of the nozzle orifice 32 .
There, will now be described a case where recording is performed through use of small dots. In this case, the decoder 45 generates first waveform selection data [ 0000 ] and second waveform selection data [ 1111 ] by translation of gradation data [ 01 ] pertaining to small dots. The switch controller controls supply of the first and second drive signals COM 1 , COM 2 to the piezoelectric vibrator 21 on the basis of the thus-generated waveform selection data.
Specifically, during the period t 10 (t 20 ), the second adjustment element P 20 is supplied to the piezoelectric vibrator 21 , whereby the potential of the vibrator is adjusted to the intermediate potential Vhm. During the periods t 11 to t 13 , the first switcher 49 is controlled and brought into a disconnected state. During periods t 21 to t 23 , the second switcher 50 is controlled and brought into a connected state.
As a result, the fourth waveform section PS 4 is supplied to the piezoelectric vibrator 21 during the period t 21 ; the fifth waveform section PS 5 is supplied to the same during the period t 22 ; and the sixth waveform section PS 6 is supplied to the same during the period t 23 . More specifically, the small dot drive pulse DP 3 is supplied to the piezoelectric vibrator 21 .
Consequently, as indicated by a bold line shown in FIG. 5, the potential of the vibrator is changed in accordance with the second drive signal COM 2 , and a nominal amount of ink is ejected from the nozzle orifice 32 by the small dot drive pulse DP 3 .
There will now be described the case of recording of middle dots. In this case, the decoder 45 generates first waveform selection data [ 0001 ] and second waveform selection data [ 1100 ] by translation of gradation data [ 10 ] pertaining to middle dots. The switch controller controls supply of the first and second drive signals COM 1 , COM 2 to the piezoelectric vibrator 21 on the basis of the thus-generated waveform selection data.
During the period t 10 (t 20 ), the first adjustment element P 0 and the second adjustment element P 20 are supplied to the piezoelectric vibrator 21 , and the potential of the piezoelectric vibrator 21 is adjusted to the intermediate potential Vhm. During the periods t 11 and t 12 , the first switcher 49 is brought into a disconnected state. During the period t 21 , the second switcher 50 is brought into a connected state. As indicated by a bold line shown in FIG. 6, the second waveform section PS 4 of the second drive signal COM 2 is supplied to the piezoelectric vibrator 21 , and the potential of the vibrator is maintained at the intermediate potential Vhm by the fourth constant potential element P 21 .
During the subsequent period t 22 , the second switcher 50 is controlled and brought into a disconnected state. During a period from the beginning of the period t 22 to the end of the period. t 13 , neither the first drive signal COM 1 nor the second drive signal COM 2 is supplied to the piezoelectric vibrator 21 . Consequently, as indicated by a semi-bold line shown in FIG. 6, the potential of the vibrator is maintained at the intermediate potential Vhm which arises before disconnection of the switchers. Since the fourth constant potential element P 21 has already been supplied to the piezoelectric vibrator 21 during the preceding period t 21 , the period of time during which the drive signals are not supplied becomes relatively short.
During the period t 13 , the first switcher 49 is controlled and brought into a connected state. During the period t 23 , the second switcher 50 is controlled and brought into a disconnected state. As indicated by the bold line shown in FIG. 6, the third waveform section PS 3 of the first drive signal COM 1 is supplied to the piezoelectric vibrator 21 . As a result, the second middle dot drive pulse DP 2 is supplied to the piezoelectric vibrator 21 , whereby a small amount of ink corresponding to a middle dot is ejected.
In the embodiment, even in the case of a medium-dot recording gradation, portions of the waveform elements constituting the first drive signal COM 1 (i.e., the third constant potential element P 9 , the first expanding element P 10 , the expansion holding element P 11 , the first election element P 12 , the damping hold element P 13 , and the damping element P 14 ) and a portion of the waveform element constituting the second drive signal COM 2 (i.e., the fourth constant potential element P 21 ) are supplied, in combination, to the piezoelectric vibrator 21 . During a period of time during which the first drive signal COM 1 cannot be supplied to the piezoelectric vibrator 21 (the periods t 11 , t 12 ), the fourth constant potential P 21 of the second drive signal COM 2 is supplied, thereby maintaining the potential of the vibrator at the intermediate potential Vhm.
This is intended for shortening, to the greatest possible extent, the period of time during which the drive signals COM 1 , COM 2 are not supplied to the piezoelectric vibrator 21 . More specifically, when a printer is used at high humidity or the insulation resistance of the piezoelectric element has dropped as a result of long-term use of the piezoelectric vibrator 21 , an electric-charge retaining capability of the piezoelectric vibrator 21 may drop. When a drop has arisen in the electric-charge retaining capability of the piezoelectric vibrator 21 , the potential of the piezoelectric vibrator 21 is gradually lowered by electric discharge which arises during a period of time in which the drive signals are not supplied to the vibrator. Therefore, when the period of time during which the drive signals are not supplied to the vibrator is long, the extent to which the potential of the vibrator is decreased becomes larger. When the next drive signals are supplied to the vibrator, a difference between the potential of the drive signal and the potential of the vibrator becomes greater. In this case, abrupt deformation arises in the piezoelectric vibrator 21 , thereby causing erroneous ejection of an ink droplet.
As in the case of this embodiment, so long as the period of time during which the drive signals COM 1 , COM 2 are not supplied to the vibrator is shortened to the greatest possible extent, the extent to which the potential of the vibrator drops can be made smaller even when a drop has arisen in the electric-charge retaining capability of the vibrator. Hence, the drive signals COM 1 , COM 2 can be supplied without any trouble.
There will now be described the case of recording of large dots. In this case, the decoder 45 generates first waveform selection data [ 1111 ] and second waveform selection data [ 0000 ] by translating gradation data [ 11 ] pertaining to large dots. In accordance with the thus-generated waveform selection data, the switch controller controls supply of the first drive signal COM 1 and the second drive signal COM 2 to the piezoelectric vibrator 21 .
Specifically, during the period t 10 (t 20 ), the first adjustment element P 0 is supplied to the piezoelectric vibrator 21 , and the potential of the vibrator is adjusted to the intermediate potential Vhm. During the periods t 11 to t 13 , the first switcher 49 is controlled and brought into a connected state. During the periods t 21 to t 23 , the second switcher 50 is controlled and brought into a disconnected state. As a result, during the period t 11 , the first waveform section PS 1 is supplied to the piezoelectric vibrator 21 . During the period t 12 , the second waveform section PS 2 is supplied to the piezoelectric vibrator 21 . Further, during the period t 13 , the third waveform section PS 3 is supplied to the same. More specifically, the first middle dot drive pulse DP 1 and the second middle dot drive pulse DP 2 are supplied to the piezoelectric vibrator 21 .
Consequently, as indicated by a bold line shown in FIG. 7, the potential of the vibrator is changed in accordance with the first drive signal COM 1 , and a small amount of ink is continuously ejected from the nozzle orifice 32 twice in response to the middle dot drive pulse. Large dots are recorded by these ink droplets.
As has been described, in the embodiment, two middle dot drive pulses DP 1 , DP 2 are included in the first drive signal COM 1 . One small dot drive pulse DP 3 is included in the second drive signal COM 2 . A period of time during which the middle dot drive pulses DP 1 , DP 2 are generated and a period of time during which the small dot drive pulse DP 2 is generated partially overlap each other, thereby shortening the recording cycle T. As a result, the piezoelectric vibrator 21 can be driven at a higher frequency, thereby enabling the recording head 8 to provide sufficient performance.
Since a portion of the waveform elements constituting the first drive signal COM 1 and a portion of the waveform elements constituting the second drive signal COM 2 are supplied, in combination, to the piezoelectric vibrator 21 , the recording head can be driven in accordance with a new pattern which is not explicitly specified by the drive signals. For example, a meniscus can be minutely vibrated without use of a dedicated vibrating pulse. Moreover, periods during which no drive signals are supplied to the piezoelectric vibrator 21 can be shortened to the shortest possible extent. As a result, a complicated control operation can be achieved while the recording head 8 is actuated at a higher frequency.
In this embodiment, the drive signals COM 1 , COM 2 are selectively supplied to the piezoelectric vibrator 21 by the first and second switchers 49 , 50 that are provided in accordance with the types of drive signals to be generated. However, the invention is not limited to such a switcher. For instance, the drive signals COM 1 , COM 2 may be selectively supplied to the piezoelectric vibrator 21 by a changeover switch shown in FIG. 8 as a second embodiment of the invention.
The changeover switch 61 is provided for each of the piezoelectric vibrators 21 . The changeover switch 61 has a first input contact point 61 a , a second input contact point 61 b , an off-contact point 61 c , all being provided in accordance with the types of drive signals to be generated, and an output terminal 61 d to be electrically connected to the piezoelectric vibrator 21 . One of the contact points 61 a through 61 c is selectively, electrically connected to the output terminal 61 d . The first input contact point 61 a is electrically connected to a line for feeding a first drive signal COM 1 ; the second input contact point 61 b is electrically connected to a line for feeding a second drive signal COM 2 ; and the off-contact point 61 c has no electrical connection.
The drive signals COM 1 , COM 2 can be selectively supplied to the piezoelectric vibrator 21 by switching the contact points 61 a through 61 c , all being electrically connected to the output terminal 61 d . Specifically, the first drive signal COM 1 can be supplied by electrically connecting the first input contact point 61 a to the output terminal 61 d . The second drive signal COM 2 can be supplied by electrically connecting the second input drive signal COM 2 to the output terminal 61 d . Neither the first drive signal COM 1 nor the second drive signal COM 2 is supplied when the off-contact point 61 c is electrically connected to the output terminal 61 d.
The operation of the changeover switch 61 is controlled by the decoder 62 and the switch controller 63 . The decoder 62 serves as a switching data generator and generates switching data representing any one of the first input contact point 61 a ([ 1 ]), the second input contact point 61 b ([ 2 ]), and the off-contact point 61 c ([ 0 ]) by translation of recording data (gradation data). The switching data are output to the switch controller 63 in synchronism with a timing output from the control logic 46 ′.
An explanation will be given by reference to a drive signal shown in FIG. 3 . In the case of gradation data [ 00 ] the decoder 62 generates switching data [ 110002 ]. The switching data are output to the switch controller 63 at a start timing of period t 10 (t 20 ), a start timing of the period t 11 (t 21 ), a start timing of the period t 12 , a start timing of a period t 22 , a start timing of a period t 13 , and a start timing of a period t 23 .
During the periods t 10 and t 11 , the changeover switch 61 is electrically connected to the first input contact point 61 a , whereby the first adjustment element P 0 and the first waveform section PS 1 of the first drive signal COM 1 are supplied to the piezoelectric vibrator 21 . Subsequently, the changeover switch 61 is switched to the off-contact point 61 c immediately before the period t 23 , whereby supply of a drive signal is interrupted. During the period t 23 , the changeover switch 61 is switched to the second input contact point 61 b , whereby the sixth waveform section PS 6 of the second drive signal COM 2 is supplied to the piezoelectric vibrator 21 .
Consequently, as in the case of the embodiment, the meniscus vibrating operation can be effected.
In the case of the gradation data [ 01 ], the decoder 62 generates switching data [ 42222 ]. As a result, the changeover switch 61 is electrically connected to the second input contact point 61 b over the entire period of the recording cycle T. The second adjustment element P 20 , the fourth waveform section PS 4 , the fifth waveform section PS 5 , and the sixth waveform section PS 6 are supplied to the piezoelectric vibrator 21 .
Consequently, as in the case of the embodiment, an amount of ink corresponding to a small dot can be ejected.
In the case of the gradation data [ 10 ], the decoder 62 generates switching data [ 222011 ]. As a result, the changeover switch 61 is electrically connected to the second input contact point 61 b immediately before start of the period t 22 , whereupon the second adjustment element P 20 and the fourth waveform section PS 4 , both belonging to the second drive signal COM 2 , are supplied to the piezoelectric vibrator 21 . The changeover switch 61 is switched to the off-contact point 61 from a start point of the period t 22 to a point immediately before start of the period t 13 , thereby interrupting supply of a drive signal. Subsequently, the changeover switch 61 is switched to the first input contact point 61 a during the period t 13 , whereupon the third waveform section PS 3 of the first drive signal COM 1 is supplied to the piezoelectric vibrator 21 .
Consequently, as in the case of the embodiment, an ink droplet corresponding to a middle dot can be ejected.
In the case of the gradation data [ 11 ], the decoder 62 generates switching data [ 111111 ]. As a result the changeover switch 61 is electrically connected to the first input contact point 61 a over the entire period of the recording cycle T. The first adjust element P 0 , the first waveform section PS 1 , the second waveform section PS 2 , and the third waveform section PS 3 , all belonging to the first drive signal COM 1 , are supplied to the piezoelectric vibrator 21 .
Consequently, as in the case of the embodiment, an ink droplet corresponding to a large dot can be ejected.
By such a configuration, control of one changeover switch 61 with regard to one piezoelectric vibrator 21 is sufficient, and hence simplification of control of the switcher can be attempted.
Here, the invention is not limited to the above-described embodiment and is susceptible to various modifications within the scope of the invention defined by the appended claims.
In connection with the pressure generating element, the embodiment has described a case where the piezoelectric vibrator 21 of so-called longitudinal vibration mode is used. However, the invention can be carried out in the same manner, through use of a piezoelectric vibrator of so-called deflection vibration mode. Alternatively, an electrostatic actuator may be used in addition to a piezoelectric vibrator.
The embodiment has described the two types of drive signals COM 1 , COM 2 . However, even when three or more types of drive signals are generated, the invention can be carried out in the same manner.
The invention can be applied to plotters, facsimiles, copiers, or various types of ink jet recording apparatuses, as well as to printers.
The invention can be also applied to display manufacturing apparatuses, electrode forming apparatuses, biochip manufacturing apparatuses, or various types of liquid jetting apparatuses, as well as ink jet recording apparatuses. In such cases, one ordinary skilled in the art can easily realize that the words “ink”, “recording”, “small dot”, “medium dot”, “large dot” and “recording gradation” used in the foregoing explanations may be respectively replaced with “liquid”, “jetting”, “small droplet”, “medium droplet”, “large droplet” and “jetting amount”. | A jetting head is provided with a nozzle orifice, a pressure chamber communicated with the nozzle orifice, and a piezoelectric element which is deformable to cause pressure fluctuation to liquid contained in the pressure chamber. A drive signal generator simultaneously generates a plurality of drive signals, each provided with waveform elements including at least one drive pulse in every unit jetting cycle. The drive pulse deforms the piezoelectric element to cause such pressure fluctuation as to eject a liquid droplet from the nozzle orifice. A switcher selectively supplies at least one of the waveform elements included in one of the drive signals to the piezoelectric element. A switch controller controls a selective supply operation of the switcher in accordance with amount data which indicates an amount of the liquid droplet to be ejected. A time period in which the drive pulse is generated in one of the drive signal and that in another one of the drive signals overlap at least partly. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic vital-sign monitoring system, and more particularly to a multifunctional vital-sign monitoring system with a database such as blood pressure & heart frequency spectrum monitor, blood oxygen & heart frequency spectrum monitor, electrocardiogram & heart frequency spectrum monitor or patient monitor for monitoring heart frequency spectrum.
2. Description of the Prior Art
In recent years, population ageing and low birth rate have gradually become a trend. Therefore, designing and implementing for the elder community (retirement community) is a significant target for community development. Regarding to health care in the community for elders, not only portable electronic are necessary to detect physiological values such as blood pressure, heart rate etc., but a more completed telecare system is required to monitor users' health status. By using medical instruments of telecare system, nursing staff or family members can monitor physiological values such as heart rate, blood pressure or heart frequency spectrum for elders, which enables long-distance caregivers to track and record health status for elders.
By measuring heart rate signals, results can be obtained and then be transformed to frequency spectrum diagram. Transformation for frequency domain uses fast Fourier transform (FFT) algorithm. Generally, the frequency spectrum diagram has 3 to 5 main frequency waveforms. The first main frequency waveform corresponds to heart rate frequency. If there are several disorder frequency waveforms beside the main frequency waveforms, it means the heart rate status appears irregular and can be considered abnormal. Thus, heart rate frequency spectrum can be used to determine heart status.
Because general electronic vital-sign monitoring devices are portable and easy to operate, they are very popular over hospitals, clinics and nursing centers. However, the function of monitoring heart rate frequency spectrum is not included. For elders or patients who need special health care in the community, general electronic vital-sign monitoring devices cannot regularly monitor their heart status.
Since general electronic vital-sign devices cannot detect heart frequency spectrum, users who desire to know heart status must go to major hospitals or medical center for precise examination and physician diagnose, which is very inconvenient especially for patients with mobility problems. If general electronic vital-sign monitoring devices, which are able to detect measuring blood pressure, blood oxygen, heart rate and electrocardiogram etc. used in hospital or clinics or telecare center, can also obtain information of heart frequency spectrum, heart status can be monitored in real-time and it will be very practicable and convenient to patients, elders and general users.
Accordingly, it is highly desirable to develop an electronic vital-sign monitoring system to help patients, elders and general users to monitor their physiological values and heart status immediately.
SUMMARY OF THE INVENTION
The present invention relates to an electronic vital-sign monitoring system which not only has original detection functions but also can detect heart frequency spectrum and offers telecare service. For patients, elders and general users, it can provide proper assistance according to different requirements.
In order to achieve objectives aforementioned, according to one embodiment of the present invention, an electronic vital-sign monitoring system comprises a database; a detection unit, for detecting a physiological value; a processing unit, connected to the detection unit, for computing the physiological value and obtaining a heart frequency spectrum; and a transfer unit, electrically connected to the processing unit, for transferring the physiological value and the heart frequency spectrum to the database, wherein the database is a cloud database or a local database.
According to another embodiment of the present invention, an electronic vital-sign monitoring device is electrically connected to an external electronic device to compose an electronic vital-sign monitoring system further comprising a database, wherein the electronic vital-sign monitoring device comprises a detection unit, for detecting an analogous signal of a physiological value; a conversion unit, connected to the detection unit, for converting the analogous signal to a digital signal of the physiological value; and a connection unit, electrically connected to the conversion unit and the external electronic device. The external electronic device computes the digital signal and obtains a heart frequency spectrum.
The objective, technologies, features and advantages of the present invention will become more apparent from the following description in conjunction with the accompanying drawings, wherein certain embodiments of the present invention are set forth by way of illustration and examples.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the accompanying advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a block diagram schematically illustrating the structure of the electronic vital-sign monitoring system according to one embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating the configuration of the electronic vital-sign monitoring system according to another embodiment of the present invention; and
FIG. 3 is a block diagram schematically illustrating the structure of the electronic vital-sign monitoring system according to FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
The detailed description is provided below and the preferred embodiments described are only for the purpose of description rather than for limiting the present invention.
FIG. 1 is a block diagram schematically illustrating the structure of the electronic vital-sign monitoring system according to one embodiment of the present invention. As shown in the figure, an electronic vital-sign monitoring system 10 comprises a database; a detection unit 11 , for detecting a physiological value; a processing unit 12 , connected to the detection unit 11 , for computing the physiological value and obtaining a heart frequency spectrum; and a transfer unit 13 , electrically connected to the processing unit 12 , for transferring the physiological value and the heart frequency spectrum to the database 30 .
Continue the above description, as shown in FIG. 1 , the electronic vital-sign monitoring system 10 further comprises a display unit 14 , a memory unit 15 and a power unit 16 , wherein the display unit 14 is connected to the processing unit 12 for displaying the physiological value and the heart frequency spectrum; the memory unit 15 is connected to the processing unit 12 for storing the physiological value and the heart frequency spectrum; the power unit 16 is connected to the processing unit 12 and the detection unit 11 for providing power.
In one embodiment, the detection unit 11 is an electronic blood pressure monitor for detecting physiological information such as blood pressure. The database 20 can be a cloud database or a local database. After receiving the physiological value or heart frequency spectrum, the database will then integrate and archive the data to enable the subjects, their family members or nursing staff to view the results on the internet. Once the physiological value or heart frequency spectrum appears abnormal or exceed threshold value, reporting mechanism will be activated to inform the subjects, their family members and nursing staff. On the other hand, the electronic vital-sign monitoring system can be a single functional system for detecting physiological values or a multifunctional patient monitoring system.
FIG. 2 is a schematic diagram illustrating the configuration of the electronic vital-sign monitoring system according to another embodiment of the present invention. As shown in the figure, an electronic vital-sign monitoring system 10 comprises an electronic vital-sign monitoring device 40 , an external electronic device 20 and a database 30 , wherein the electronic vital-sign device 40 is electrically connected to the external electronic device 20 . FIG. 3 is a block diagram schematically illustrating the structure of the electronic vital-sign monitoring system according to FIG. 2 . As shown in the figure, the electronic vital-sign monitoring device 40 comprises a detection unit 41 , for detecting a analogous signal of a physiological value; a conversion unit 42 , connected to the detection unit 41 , for converting the analogous signal to a digital signal of the physiological value; and a connection unit 43 , electrically connected to the conversion unit 42 and the external electronic device 20 . The external electronic device 20 computes the digital signal and obtains a heart frequency spectrum and then stores the physiological value and the heart frequency spectrum to the database 30 . On the other hand, the external electronic device 20 further provides power to the electronic vital-sign monitoring device 40 . In one embodiment, the connection unit 43 is a USB port or a RS232 port.
Continue the above description, the external electronic device 20 also comprises a display unit 24 for displaying information of physiological values and heart frequency spectrum. In one embodiment, the display unit 24 is LCD or LED. The external electronic device 20 can be a desktop computer, a laptop or a PDA. Users can use the external electronic device 20 to give commands to the electronic vital-sign monitoring device 40 for detection. The external device 20 can transfer the physiological value or the heart frequency spectrum to the database 30 by wired or wireless means such as wired internet, wireless internet, landline phone or mobile phone. After receiving the information of the physiological value or the diagram of the heart frequency spectrum, the database will then integrate and archive the data to enable subjects, their family members or nursing staff to view the results on the internet. Once the physiological value or heart frequency spectrum appears abnormal or exceeds threshold value, reporting mechanism will be activated to inform the subjects, their family members or nursing staff by wired or wireless means such as wired internet, wireless internet, landline phone or mobile phone.
According to the aforementioned description, the present invention incorporates a new function of detecting heart frequency spectrum into general electronic vital-sign monitoring system so that it can immediately offer information of heart status to patients, elders or general users who need regular care or instant assistance. Furthermore, the database enables subjects, their family members or general users to track information of physiological values or heart frequency spectrum by wire or wireless means such as on the internet. Via the reporting mechanism, subjects, their family members or nursing staff can be urgently informed once the physiological value or heart frequency spectrum appears abnormal or exceeds threshold value so as to achieve telecare service.
The present invention provides an electronic vital-sign monitoring system for detecting blood pressure, blood oxygen or electrocardiogram information with the novel function of detecting heart frequency spectrum. Regarding to patients, elders or general users who need regular care or instant assistance, this system can accurately determine heart status and offer necessary information of physiological values or heart frequency spectrum to family members, telecare center, hospital or nursing staff. Moreover, when using monitoring system to regularly monitor blood pressure, blood oxygen or electrocardiogram of patients, if heart frequency spectrum appears abnormal, nursing staff or related people can inquire patients about their body status. If feeling sick, further examination of the heart can be arranged in major hospitals.
In conclusion, the present invention provides an electronic vital-sign monitoring system which not only has original detection functions but also can detect heart frequency spectrum and offer telecare service. For patients, elders and general users, it can provide proper assistance according to different requirements.
While the invention is susceptible to various modifications and alternative forms, a specific example thereof has been shown in the drawings and is herein described in detail. It should be understood, however, that the invention is not to be limited to the particular form disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims. | A electronic vital-sign monitoring system is provided here, which uses an external electronic device to compute a physiological value detected by an electronic vital-sign monitoring device and obtain a heart frequency spectrum; and provide power to the electronic vital-sign monitoring system; and further transfer the computed physiological value and the heart frequency spectrum to a database for data integration and incident reporting. In addition to the original function of detecting physiological values, the electronic vital-sign monitoring system further can detect heart frequency spectrum and offers telecare service to help patients, elders and general users according to different requirements. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field of the Invention
[0002] The present invention relates generally to very high performance microelectronic chips used in computers, microprocessors, microcontrollers, sensors, communication devices and the like. In particular, the invention relates to the interconnect wiring networks on such chips, with the goal of significantly reducing the signal propagation delay associated with these wires in the networks using copper wiring embedded in a very low k dielectric medium possessing engineered porosity formed after the interconnects are formed.
[0003] 2. Description of the Background Art
[0004] High performance microprocessor, microcontroller and communication chips require very high speed interconnects between the active transistor devices which are used to perform the various functions such as logical operations, storing and retrieving data, providing control signals and the like. With the progress in the transistor device technology leading to the present ultra large scale integration, the overall speed of operation of these advanced chips are beginning to be limited by the signal propagation delay in the interconnection wires between the individual devices on the chips. The signal propagation delay in the interconnects is dependent on the RC product wherein, R denotes the resistance of the interconnect wires and C represents the overall capacitance of the interconnect scheme in which the wires are embedded. Use of copper instead of Al as the interconnect wiring material has allowed the reduction of the resistance contribution to the RC product.
[0005] The current focus in the microelectronics industry is to reduce interconnect capacitance by the use of lower dielectric constant (k) insulators in building the multilayered interconnect structures on chips.
[0006] One prior art method of creating interconnect wiring network on such small a scale is the dual damascene (DD) process schematically shown in FIG. 1 . In the standard DD process, an inter metal dielectric (IMD), shown as two layers 1110 , 1120 is coated on substrate 1100 as depicted in FIG. 1 a. The via level dielectric 1110 and the line level dielectric 1120 are shown separately for clarity of the process flow description.
[0007] In general, these two layers can be made of the same or different insulating films and in the former case applied as a single monolithic layer. A hard mask layer or a layered stack 1130 is optionally employed to facilitate reactive ion etch selectivity and to serve as a polish stop. The wiring interconnect network consists of two types of features: line features that traverse a distance across the chip, and the via features which connect lines in different levels of interconnects in a multilevel stack together. Historically, both layers are made from an inorganic glass like silicon dioxide (SiO 2 ) or a fluorinated silica glass (FSG) film deposited by plasma enhanced chemical vapor deposition (PECVD).
[0008] In the dual damascene process, the position of the lines 1150 and the vias 1170 are defined lithographically in photoresist layers 1500 and 1510 respectively, FIGS. 1 b and 1 c, and transferred into the hard mask and IMD layers using reactive ion-etching processes. The process sequence shown in FIG. 1 is called a “line-first” approach.
[0009] After the trench formation, lithography is used to define a via pattern 1170 in the photoresist layer 1510 and the pattern is transferred into the dielectric material to generate a via opening 1180 , FIG. 1 d.
[0010] The dual damascene trench and via structure 1190 is shown in FIG. 1 e after the photoresist has been stripped. This recessed structure 1190 is then coated with a conducting liner material or material stack 1200 that serves to protect the conductor metal lines and vias and serves as an adhesion layer between the conductor and the IMD. This recess is then filled with a conducting fill material 1210 over the surface of the patterned substrate. The fill is most commonly accomplished by electroplating of copper although other methods such as chemical vapor deposition (CVD) and other materials such as Al or Au can also be used. The fill and liner materials are then chemical-mechanical polished (CMP) to be coplanar with the surface of the hard mask and the structure at this stage is shown in FIG. 1 f.
[0011] A capping material 1220 is deposited as a blanket film, as is depicted in FIG. 1 g to passivate the exposed metal surface and to serve as a diffusion barrier between the metal and any additional IMD layers to be deposited over them. Silicon nitride, silicon carbide, and silicon carbonitride films deposited by PECVD are typically used as the capping material 1220 . This process sequence is repeated for each level of the interconnects on the device. Since two interconnect features are simultaneously defined to form a conductor in-laid within an insulator by a single polish step, this process is designated a dual damascene process.
[0012] In order to lower the capacitance, it is necessary to use lower k dielectrics such as organic polymers and spin on organo-silicate glasses which have k values in the 2.5 to 3.0 range instead of the PECVD silicon dioxide based dielectrics (k=3.6 to 4.0). The k value can be further reduced to 2.2 (ultra low k) and even below 2.0 (extreme low k) by introduction of porosity in these insulators. The minimum value of the dielectric constant is 1.0. For the purpose of brevity, we shall refer to these ultra low k and extreme low k materials collectively as very low k materials (i.e., in the range of about 2.2 and below) in this document.
[0013] Although a tunable range of k values is possible with this set of very low k materials, there are several difficulties in integrating these materials with copper interconnects by the dual damascene process described above.
[0014] These low k dielectrics have a much lower elastic modulus, fracture toughness and cohesive strength than the silicon dioxide or FSG films and their adhesion to typical hard mask layers used in current state of the art copper interconnect is also correspondingly inferior. As a result, when the CMP of the copper fill is attempted during the dual damascene interconnect build, delamination occurs either cohesively in the weak low k material or adhesively at the interface between the very low k material and the hard mask. This renders the DD process highly impractical from the point of view of manufacturability and yields.
[0015] There are other issues associated with integrating very low k porous dielectrics with interconnected porosity that pertain to the metallization and plating of wiring layers.
[0016] In particular, deposition of barrier layers such as tantalum, tantalum nitide, tantalum silicon nitride, titanium silicon nitride, tungsten and tungsten nitride and the like by chemical vapor deposition or atomic layer deposition can lead to the penetration of the gaseous precursors used into the pores resulting in the deposition of the conductive barriers in these pores. This in turn can lead to line to line shorting. Poor coverage of the rough surfaces of the porous dielectric surfaces by these barriers can also lead to infiltration of the plating and cleaning solutions into the dielectric. Poor coverage can also lead to Cu diffusion into the dielectric during subsequent thermal processing cycles which can cause a degradation in the electrical breakdown behavior of the intermetal dielectric (IMD).
[0017] One prior art method to overcome some of these difficulties is described in assignee's U.S. Pat. No. 6,451,712 (Dalton et al.), the contents of which are hereby incorporated by reference herein.
[0018] In this method, the pore generating component (known as porogen) used in the porous dielectric formulation is retained in the dielectric film during the dual damascene patterning, barrier/liner deposition, plating and CMP so that these steps are performed in a nonporous dielectric. Subsequent to the CMP step, the porogen is removed from the dielectric by a thermal anneal rendering the dielectric porous. This method requires that the hard mask used in the DD fabrication be not only a good CMP stop layer but also be permeable to the porogen species during the thermal anneal step. Further, it is required that the dielectric be able to release the porogen without significant shrinkage so that dimensional changes or thermal stresses in the interconnect is avoided. These requirements are often conflicting in nature and are restrictive of the extent of porosity that can be generated and hence the lowering of the dielectric constant of the IMD. The pores formed are in general randomly oriented and have a range of sizes. Such a porous structure is generally weaker in mechanical strength and sometimes exhibits spatial variability in the dielectric properties as a result of the pore size distribution.
[0019] A second prior art method described in a copending patent application Ser. No. 10/280,283 circumvents the issues of porous IMD integration by building the interconnects by a dual damascene process in a support dielectric, etching out the said support dielectric form between the lines only, filling the etched out gaps with a porous low k dielectric and polishing back to planaraize the top of the interconnects.
[0020] While this prior art method does avoid all the issues associated the direct DD integration of the porous IMDs, it requires that the porous IMD be able to fill line to line gaps and withstand CMP planarization which can restrict the choices of the porous IMD. Further, additional process steps to etch the support dielectric and fill and polish the gapfill porous dielectric are needed which can add to manufacturing cost and lead to possible reduction in yield.
[0021] It is therefore an object of this invention to produce an interconnect structure with very low effective dielectric constant (hereinafter “keff”) by avoiding the above described issues associated with porous dielectrics and the prior art methods of forming integrated structures using them.
[0022] It is further an object of this invention to overcome these difficulties, by performing all the steps required for interconnect fabrication using a dielectric without any porosity (robust enough to withstand state-of-the-art semiconductor interconnect fabrication techniques) and introducing nanoscale porosity with controlled size and orientation into it after the dual damascene interconnect structure is formed.
SUMMARY OF THE INVENTION
[0023] This invention pertains to the very high performance microelectronic chips used in computers, microprocessors, microcontrollers, sensors, communication devices and the like. In particular, the inventive structures described herein pertain to the interconnect wiring networks on such chips, with the goal of significantly reducing the signal propagation delay associated with these wires. The inventive methods detailed and claimed provide the integration steps required to fabricate these high performance interconnect networks with copper wiring embedded in a very low k dielectric medium comprising engineered porosity characterized by a specific pore orientation, size and spacing forming a regular array of pores; further, the engineered porosity is formed after the interconnects are formed.
[0024] The interconnect structure of the present invention used for the purposes set forth above embodies a first dielectric material encasing a set of conductive vias and supporting thereon a set of conductive lines on its top surface. There is, in addition, a second dielectric disposed between the set of conducting lines and possessing a top surface and a bottom surface. The second dielectric contains a regular array of nanocolumnar pores which are sealed off at the top by a layer of a third dielectric layer which serves to protect the top surface of the conductive lines. Specific copolymers are used as templates or stencils to obtain the “regular array” in accordance with the present invention. The expression “regular array” is used herein to designate an ordered arrangement of separated phases, such as in a hexagonal closed pack pattern. For the purpose of this disclosure, “nanocolumnar” describes a structure generated from the regular array noted above, which is transferred anisotropically into an underlying material stack which can include one or more of the layers selected from the group comprising: hardmask, cmp stop, etch stop, line-level dielectric and via level dielectric. The invention generally relates to generating nanocolumnar voids or nanocolumnar pillars in a dielectric stack in order to reduce the effective dielectric constant of the interconnect structure.
[0025] These and other aspects of the present inventive method are illustrated in the figures listed below and described in greater detail in the following section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIGS. 1 a - 1 g: Dual damascene process flow (prior art)
[0027] FIGS. 2 a - 2 h : Process flow for current invention as found in embodiment 1
[0028] FIGS. 3 a - 3 c : Process flow for embodiment 2
[0029] FIGS. 4 a - 4 f : Illustrations of embodiment 3
DETAILED DESCRIPTION OF THE INVENTION
[0030] The inventive method taught is described as the “Nanocolumnar Dielectric” integration scheme. Different embodiments of this general inventive method and the resulting structures are described in detail below.
[0031] The method of the first embodiment begins with the fabrication of a dual damascene interconnect structure comprising the prior art steps described earlier and depicted in the steps FIG. 1 a through FIG. 1 f resulting in embedded Cu lines coplanar with the IMD surface. The DD structure is built using IMD materials, which are preferably more robust compared with the very low k dielectrics described in the prior art. Such a robust IMD material can be selected from, but not restricted to, the set comprising (a) organic thermoset dielectrics such as polyarylene ethers (for example SiLK™ produced by Dow Chemical Company or GX3™ produced by Honeywell Microelectronic Materials) (b) spun on silica or organosilicate glass films, (c) hydrogenated amorphous dilectrics comprising Si, C, H and O and deposited by plasma enhanced chemical vapor deposition (PECVD), (d) undoped silicon oxide glass (USG) and fluorine doped silicon oxide glass (FSG) deposited by PECVD, (e) porous versions of (a)-(d). It is required that the material selected be robust enough to withstand an interconnect build by the prior art methods and result in acceptable levels of yield.
[0032] It is also preferred that the two IMD layers 1110 and 1120 are identical, although this is not required for the formation of the final structure.
[0033] Upon the dual damascene structure prior to cap deposition, shown in FIG. 1 f, a two layer structure that consists of a random brush polymer 2100 and diblock copolymer film 2110 is coated and subjected to a thermal cure. The random brush polymer is an oriented layer that covers the surface below and enables the diblock polymer to form a reliable film on top that will phase separate into the regular domains upon curing. As a result of the cure step, the diblock copolymer separates into hexagonal close-packed domains of its constituent blocks. The two phases are represented schematically in FIG. 2 a by 2110 A and 2110 B. Typical thermal cure cycle entails baking at between about 100° C. and about 300° C., preferably about 200° C. for 30 to 60 minutes. In the exemplary case of a polymethylmethacrylate-polystyrene (PMMA-PS) system, the resulting structure consists circular regions of PMMA roughly 12 to 25 nm in diameter located at 30-40 nm centers distributed uniformly in a matrix of PS.
[0034] The configuration of the diblock polymer is an essential feature of the present invention. In forming the diblock copolymer used in the present invention, the Flory-Huggins interaction parameter χ determines the thermodynamics of mixing of two polymers. The parameter χ is a function of the incompatibility/repulsion of monomers of different species. The extent of segregation of a copolymer is characterized by the product χN, where N is the copolymer degree of polymerization, i.e., the number of monomer units comprising the polymer. Monodisperse diblock copolymers will spontaneously phase separate at temperatures above their T g (glass transition temperature), if they have a sufficiently large χN, which generally means that χN) 10 . As N also determines the dimensions of the resulting microphase separated polymer, it is clear that the spontaneous formation of smaller nanostructures requires a larger compatibility (i.e. larger χ) between polymer blocks.
[0035] For example, χ for polystyrene and polymethyl methacrylate is roughly 0.017 at 200° C., while χ for polystyrene and polyimide is roughly three times larger (0.046). Based upon these figures, one would expect spontaneous nanostructure formation in the polystyrene/polyimide diblock copolymers at approximately 3 times smaller N in this example.
[0036] Other examples of copolymers that may phase separate under the proper process conditions are poly(dimethylsiloxane-b-methylmethacrylate), poly(dimethylsiloxane-b-ethylene oxide, poly(t-butylacrylate-b-vinyl pyridine), poly(isobutylene-b-ε-caprolactam), poly(styrene-b-ε-caprolactam), or any other diblock copolymer that can form a phase-separated pattern.
[0037] The diblock film is then “developed” using a solution that preferentially dissolves the one phase to leave a regular array of nanoscale holes 2130 (where PMMA has been dissolved away) in the polymeric matrix 2140 . For the poly(MMA-b-S) example, dilute acetic acid selectively dissolved the MMA block. The resulting structure after the aforementioned steps is shown schematically in cross section in FIG. 2 b and a top down scanning electron micrograph example of the hexagonal array of holes 2130 now present in the PS matrix 2140 is shown in FIG. 2 c.
[0038] In the next step, hole pattern 2130 is transferred into top layer of the IMD stack 1130 to form a hole array 2150 by using a reactive ion etching (ME) process that selectively etches the hard mask layer 1130 without attacking the polymer matrix 2140 , as depicted in FIG. 2 d.
[0039] By appropriately changing the RIE process chemistry and conditions, the etched holes 2150 in the hard mask layer 1130 are transferred selectively into the IMD layers 1110 and 1120 resulting in the nanocolumnar porosity structure shown in FIG. 2 e , comprising nanocolumnar holes 2160 in the IMD stack 1110 , 1120 , 1130 .
[0040] Holes 2150 and 2160 are substantially equal in diameter to the holes 2130 in the developed diblock polymer layer. The depth to which the holes 2160 extend into the IMD layers can be varied. It is preferred that the holes extend through IMD layers 1110 and 1120 , as shown in FIG. 2 e , so that the lower dielectric constant afforded by the nanocolumnar porosity is realized to the maximum.
[0041] Alternatively, the holes can be etched to extend only into IMD 1110 and stop on 1120 or extend slightly below the interface between the layers 1110 and 1120 as shown in FIGS. 2 f and 2 g respectively. These structures would lead to a slightly a higher keff but afford higher mechanical strength than the structure depicted in FIG. 2 e.
[0042] FIGS. 2 e - 2 g are shown with the diblock polymer remnants removed. This is accomplished by a suitable wet or dry etch process known in the prior art on the express condition that the process does not affect the Cu lines or the etched IMD layers. Wet chemical cleans in mild alkaline conditions as those used for photoresist stripping, mild acidic solutions as those used for cleaning oxidized copper surfaces, plasma ashing or combinations thereof can be employed towards this end.
[0043] Subsequent to forming the holes 2160 , into the ILD as shown in FIG. 2 e , respectively, a cap layer 2190 (illustrated for the case after step shown in FIG. 2 f ) is used to pinch off the top of the nanocolumnar porous IMD stack. Hole arrays 2170 and 2180 in FIGS. 2 f and 2 g would also be capped off prior to further processing in a similar fashion. It is preferred that the dielectric 2190 used for this purpose also act as a copper diffusion barrier since it covers the tops of the metallic lines. Several methods of deposition could be used including but not restricted to PECVD, CVD and spin on coating and curing. Because of the small diameter of the holes, this segment of the process can be adjusted to just penetrate the nanocolumnar holes 2160 ( 2170 , and 2180 ) enough to close them off without substantially encroaching down into the holes 2160 ( 2170 , and 2180 ). An optional touch up CMP can be employed to improve planarity after the deposition of the layer 2190 . The resulting structure at this juncture is shown in FIG. 2 h . Multilevel structures with nanocolumnar IMD can be fabricated by repeating the steps described in FIGS. 2 a - 2 h as required.
[0044] In another embodiment (embodiment 2) of this inventive method, illustrated in FIG. 3 , the following sequence of steps is additionally performed after the holes 2160 (and holes 2170 and 2180 by analogy) are formed into the IMD and the diblock polymer layer has been etched away.
[0045] An additional RIE step is performed to etch and recess the IMD layer 1130 and optionally a small depth into layer 1120 so that the etched surface is recessed below the surface of the conductive fill 1210 in the structure as shown in FIG. 3 a . This recess 3000 is chosen to be about 10 nm to 60 nm but preferably about 20 nm.
[0046] The pinch off dielectric cap 2170 is then deposited such that it pinches off the holes 2160 in the recessed region created above, and covers over the surface of conductive fill 1210 .
[0047] An optional CMP step can be employed to planarize the surface of dielectric cap 2170 . The net result of this sequence of steps is to provide a non perforated dielectric region 2171 in gaps between conductive lines 1210 as illustrated in FIG. 3 b . A second cap dielectric 2190 is deposited over the entire structure to cover the top surface of regions 2171 and the tops of the conducting lines 1210 as illustrated in FIG. 3 b.
[0048] During the subsequent build of the next level of interconnect on top, the cap dielectric layer 2190 over lines 1210 can be etched to provide electrical contact to the top of conductive fill 1210 without any concern regarding the etch through of the nonperforated dielectric region 2171 due to any overlay misalignments 3010 between the levels as shown in FIG. 3 c . This is because the nonperforated dielectric 2171 is present in region between the metal lines. Without this procedure, if misalignment between levels leads to etch through of the cap 2190 in the line gaps, metal deposition and plating solutions from the build of the upper level could penetrate into the columnar holes 2160 causing defects, yield loss and reliability concerns. Thus, the added steps provide protection against lithographic misalignment between levels during the build of multilevel interconnects using this inventive method. The steps shown in FIGS. 3 a - 3 c can also be practiced on the more robust nanocolumnar structures illustrated in FIGS. 2 e and 2 f to derive similar benefits.
[0049] In the third embodiment of the present inventive method, the nanocolumnar diblock stencil film 2110 is generated as described earlier in reference to FIG. 2 , except that the structure is generated on a cap layer dielectric 1220 formed on top of the state of the art interconnect structure as exemplified in FIG. 1 g. This is shown schematically in FIG. 4 a . The remaining matrix 2140 of the stencil is used to transfer the pattern into the cap dielectric layer 1220 resulting in a perforated cap layer dielectric 4000 which rests on the top IMD layer 1130 . This transfer process is performed by reactive ion etching. The nanoscale pattern in the perforated cap layer dielectric is then transferred into the IMD stack using the matrix 2140 and patterned cap layer dielectric 4000 as a mask as shown in FIG. 4 b . The nanoscale pattern is transferred into the IMD stack 1110 , 1120 , 1130 generating columnar holes 4010 . Analogous structures to those in FIGS. 2 f and 2 g can also be generated by adjusting the depth of the etch into IMD stack.
[0050] A second cap layer dielectric 4020 is then deposited over the nanocolumnar holes (voids) 4010 . Depending on the cap film 4020 used and the process employed for depositing the same, a slight topography may remain as is shown schematically in FIG. 4 d . Optionally, layer 4020 may be polished or etched to result in the planarized cap layer 4030 . The cap layer dielectrics 1220 and 4020 may be identical or may be different. Since both are in contact with the metal surface, it is preferable that they both are acceptable as Cu Diffusion barriers, and enable good copper electromigration life times.
[0051] The cap layer 1220 is selected based on its ability to have a reactive ion etch selectivity to the IMD layers 1110 and 1120 and the hard mask layer 1130 , since this cap layer is used to transfer hole patterns into these layers. Additionally it is preferred that the cap layer have a moderately low dielectric constant (5 or less), be a barrier to copper diffusion outwards from the Cu lines and oxygen or moisture diffusion inwards to the lines. By way of example, this cap layer can be selected from the group comprising amorphous hydrogenated PECVD films and spin on dielectrics containing Si and C, hydrogen and optionally O and or N.
[0052] Several optional steps can be applied to this third embodiment to generate structures similar to those of FIG. 2 and FIG. 3 . As with the process in FIG. 3 , the perforated cap layer 4000 may be etched away so that the structure would be identical to that of FIG. 2 e . Further, the IMD may be recessed as described in FIG. 3 , such that the final structure is identical to the final structure in FIG. 3 .
[0053] As is evident from the above description, the DD interconnects are fabricated using robust IMD films and a regularly spaced and vertically oriented array of holes with nanometer scale diameter are formed in the IMD after the fact to lower the effective dielectric constant of the structure by between about 15 up to about 70%. The need to handle fragile dielectrics during the DD processing steps is completely avoided. It should be noted that analogous structures with vertical pillars rather than vertical holes may be fabricated using this technique by appropriately selecting the volume fraction and chemistry of the two phases in the diblock polymer system. Additionally other regular arrays of nanoscale patterns may also be produced and used.
[0054] Although the invention describes the formation of nanocolumnar IMDs by the exemplary use of diblock copolymer as the template, other templates for forming a regular hole arrays such as using a photoresist patterned by optical lithography, ion beam, x-ray or e-beam lithography; imprinting a hole pattern in a resist using imprint lithography; patterning regular hole arrays on photoresists using diffraction patterns or holography; oblique deposition of a thin dielectric with a nanocolumnar pore structure and the like can be employed without deviating from the spirit of the invention. Essentially, the effective dielectric constant of any single or dual damascene interconnect structure may be improved by applying and transferring vertically oriented nanostructures as taught in the present invention.
[0055] 2Thus, while there have been shown, described and pointed out fundamental novel features of the invention as applied to currently preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the method and compositions illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended herewith. | A method for forming an interconnect structure with nanocolumnar intermetal dielectric is described involving the construction of an interconnect structure using a solid dielectric, and introducing a regular array of vertically aligned nanoscale pores through stencil formation and etching to form a hole array and subsequently pinching off the tops of the hole array with a cap dielectric. Variations of the method and means to construct a multilevel nanocolumnar interconnect structure are also described. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 11/544,778 filed on Oct. 10, 2006, all of which are herein incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates to MEMS devices and in particular MEMS devices that vaporize liquid to generate a vapor bubble during operation.
CO-PENDING APPLICATIONS
[0003] The following applications have been filed by the Applicant simultaneously with the present application:
[0000]
11/544763
11/544764
11/544765
11/544766
11/544767
11/544768
11/544769
11/544770
11/544771
11/544772
11/544773
11/544774
11/544775
11/544776
11/544777
11/544779
[0004] The disclosures of these co-pending applications are incorporated herein by reference.
CROSS REFERENCES TO RELATED APPLICATIONS
[0005] Various methods, systems and apparatus relating to the present invention are disclosed in the following U.S. patents/patent applications filed by the applicant or assignee of the present invention:
[0000]
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BACKGROUND OF THE INVENTION
[0006] Some micro-mechanical systems (MEMS) devices process or use liquids to operate. In one class of these liquid-containing devices, resistive heaters are used to heat the liquid to the liquid's superheat limit, resulting in the formation of a rapidly expanding vapor bubble. The impulse provided by the bubble expansion can be used as a mechanism for moving liquid through the device. This is the case in thermal inkjet printheads where each nozzle has a heater that generates a bubble to eject a drop of ink onto the print media. In light of the widespread use of inkjet printers, the present invention will be described with particular reference to its use in this application. However, it will be appreciated that the invention is not limited to inkjet printheads and is equally suited to other devices in which vapor bubbles formed by resistive heaters are used to move liquid through the device (e.g. some ‘Lab-on-a-chip’ devices).
[0007] The time scale for heating a liquid to its superheat limit determines how much thermal energy will be stored in the liquid when the superheat limit is reached: this determines how much vapor will be produced and the impulse of the expanding vapor bubble (impulse being defined as pressure integrated over area and time). Longer time scales for heating result in a greater volume of liquid being heated and hence a larger amount of stored energy, a larger amount of vapor and larger bubble impulse. This leads to some degree of tunability for the bubbles produced by MEMS heaters. Controlling the time scale for heating to the superheat limit is simply a matter of controlling the power supplied to the heater during the nucleation event: lower power will result in a longer nucleation time and larger bubble impulse, at the cost of an increased energy requirement (the extra energy stored in the liquid must be supplied by the heater). Controlling the power may be done by way of reduced voltage across the heater or by way of pulse width modulation of the voltage to obtain a lower time averaged power.
[0008] While this effect may be useful in controlling e.g. the flow rate of a MEMS bubble pump or the force applied to a clogged nozzle in an inkjet printer (the subject of a co-pending application referred to temporarily by Docket Number PUA011US), the designer of such a system must be wary of ensuring bubble stability. A typical heater heating a water-based liquid will generate unstable, non-repeatable bubbles if the time scale for heating is much longer than 1 microsecond (see FIG. 1 ). This non-repeatability will compromise device operation or severely limit the range of bubble impulse available to the designer.
SUMMARY OF THE INVENTION
[0009] Accordingly the present invention provides a MEMS vapour bubble generator comprising:
a chamber for holding liquid; a heater positioned in the chamber for thermal contact with the liquid; and, drive circuitry for providing the heater with an electrical pulse such that the heater generates a vapour bubble in the liquid; wherein, the pulse has a first portion with insufficient power to nucleate the vapour bubble and a second portion with power sufficient to nucleate the vapour bubble, subsequent to the first portion.
[0014] If the heating pulse is shaped to increase the heating rate prior to the end of the pulse, bubble stability can be greatly enhanced, allowing access to a regime where large, repeatable bubbles can be produced by small heaters.
[0015] Preferably the first portion of the pulse is a pre-heat section for heating the liquid but not nucleating the vapour bubble and the second portion is a trigger section for nucleating the vapour bubble. In a further preferred form, the pre-heat section has a longer duration than the trigger section. Preferably, the pre-heat section is at least two micro-seconds long. In a further preferred form, the trigger section is less than a micro-section long.
[0016] Preferably, the drive circuitry shapes the pulse using pulse width modulation. In this embodiment, the pre-heat section is a series of sub-nucleating pulses. Optionally, the drive circuitry shapes the pulse using voltage modulation.
[0017] In some embodiments, the time averaged power in the pre-heat section is constant and the time averaged power in the trigger section is constant. In particularly preferred embodiments, the MEMS vapour bubble generator is used in an inkjet printhead to eject printing fluid from nozzle in fluid communication with the chamber.
[0018] Using a low power over a long time scale (typically >>1 μs) to store a large amount of thermal energy in the liquid surrounding the heater without crossing over the nucleation temperature, then switching to a high power to cross over the nucleation temperature in a short time scale (typically <1 μs), triggers nucleation and releasing the stored energy.
[0019] Optionally, the first portion of the pulse is a pre-heat section for heating the liquid but not nucleating the vapour bubble and the second portion is a trigger section for superheating some of the liquid to nucleate the vapour bubble.
[0020] Optionally, the pre-heat section has a longer duration than the trigger section.
[0021] Optionally, the pre-heat section is at least two micro-seconds long.
[0022] Optionally, the trigger section is less than one micro-section long.
[0023] Optionally, the drive circuitry shapes the pulse using pulse width modulation.
[0024] Optionally, the pre-heat section is a series of sub-nucleating pulses.
[0025] Optionally, the drive circuitry shapes the pulse using voltage modulation.
[0026] Optionally, the time averaged power in the pre-heat section is constant and the time averaged power in the trigger section is constant.
[0027] In another aspect the present invention provides a MEMS vapour bubble generator used in an inkjet printhead to eject printing fluid from a nozzle in fluid communication with the chamber.
[0028] Optionally, the heater is suspended in the chamber for immersion in a printing fluid.
[0029] Optionally, the pulse is generated for recovering a nozzle clogged with dried or overly viscous printing fluid.
BRIEF DESCRIPTION OF DRAWINGS
[0030] Preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which:
[0031] FIGS. 1A to 1E show water vapour bubbles generated at different heating rates;
[0032] FIGS. 2A and 2B show two alternatives for shaping the pulse into pre-heat and trigger sections;
[0033] FIG. 3 is a plot of the hottest point on a heater and a cooler point on the heater for two different pulse shapes;
[0034] FIG. 4A shows water vapour bubbles generated using a traditional square-shaped pulse;
[0035] FIG. 4B shows a bubble generated using a pulse shaped by pulse width modulation;
[0036] FIGS. 4C and 4D show a bubble generated using voltage modulated pulses; and,
[0037] FIG. 5 shows the MEMS bubble generator in use within an inkjet printhead.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] In a MEMS fluid pump, large, stable and repeatable bubbles are desirable for efficient and reliable operation. To analyse the mechanisms that influence bubble nucleation and growth, it is necessary to consider the spatial uniformity of the heater's temperature profile and then consider the time evolution of the profile. Finite element thermal models of heaters in liquid can be used to show that the heating rate of the heater strongly influences the spatial uniformity of temperature across the heater. This is because since different portions of the heater are heat-sunk to different degrees (the sides of the heater will be colder due to enhanced cooling by the liquid and the ends of the heater will be colder due to enhanced cooling by the contacts). At low powers, where the time scale for heating to the superheat limit is large with respect to the thermal time scales of the cooling mechanisms, the temperature profile of the heater will be strongly distorted by cooling at the boundaries of the heater. Ideally the temperature profile would be a “top-hat”, with uniform temperature across the whole heater, but in the case of low heating rates, the edges of the temperature profile will be pulled down.
[0039] The top-hat temperature profile is ideal for maximising the effectiveness of the heater, as only those portions of the heater above the superheat limit will contribute significantly to the bubble impulse. The nucleation rate is a very strong exponential function of temperature near the superheat limit. Portions of the heater that are even a few degrees below the superheat limit will produce a much lower nucleation rate than those portions above the superheat limit. These portions of the heater have much less contribution to the bubble impulse as they will be thermally isolated by bubbles expanding from hotter portions of the heater. In other words, if the temperature profile across the heater is not uniform, there can exist a race condition between bubble nucleation on colder parts of the heater and bubbles expanding from hotter parts of the heater. It is this race condition that can cause the non-repeatability of bubbles formed with low heating rates.
[0040] The term “low heating rates” is a relative term and depends on the geometry of the heater and its contacts and the thermal properties of all materials in thermal contact with the heater. All of these will influence the time scales of the cooling mechanisms. A typical heater material in a typical configuration applicable to inkjet printers will begin to manifest the race condition if the time scale for nucleation exceeds 1 μs. The exact threshold is unimportant as any heater will be subject to the race condition and the consequent bubble instability if the heating rate is low enough. This will limit the range of bubble impulse available to the designer.
[0041] FIGS. 1A to 1E are line drawings of stroboscopic photographs of vapour bubbles 12 generated at different heating rates by varying the voltage of the drive pulse. Using a strobe with a duration of 0.3 microseconds, the images show capture the bubbles at their greatest extent. The heater 10 is 30 μm×4 μm in an open pool of water at an angle of 15 degrees from the support wafer surface. The dual bubble appearance is due to a reflected image of the bubble on the wafer surface.
[0042] In FIG. 1A , the drive voltage is 5 volts and the bubble 12 reaches its maximum extent at 1 microsecond. The bubble is relatively small but has a regular shape along the heater length. In FIG. 1B , the drive voltage decreases to 4.1 volts and the time to maximum bubble growth increases to 2 microseconds. Consequently, the bubble 12 is larger but bubble irregularities 14 start to occur. The pulse voltage progressively decreases in FIGS. 1C , 1 D and 1 E (3.75V, 3.45V and 2.95V respectively). As the voltage decreases, so to does the heating rate, thereby increasing the time scale for reaching the liquid superheat limit. This allows more time for heat leakage into the liquid, resulting in a larger amount of stored thermal energy and the production of more vapor when bubble nucleation occurs. In other words, the size of the bubble 12 increases. Lower voltages therefore result in greater bubble impulse, allowing the bubble to grow to a greater extent. Unfortunately, the irregularities 12 in the bubble shape also increase. Hence the bubble is potentially unstable and non-repeatable when the time scale for heating to the superheat limit exceeds 1 microsecond. In FIGS. 1A to 1E , the time to maximum bubble size is 1, 2, 3, 5, and 10 microseconds respectively.
[0043] The invention provides a way of avoiding the instability caused by the race condition so that the designer can use low heating rates to generate a large bubble impulse on a heater with fixed geometry and thermal properties. FIGS. 2A and 2B shows two possibilities for driving the heaters to produce large, stable bubbles. In FIG. 2A , the drive circuit uses amplitude modulation to decrease the power of the pre-heat section 16 relative to the trigger section 18 . In FIG. 2B , pulse width modulation of the voltage (creating a rapid series of sub-ejection pulses) can be used to reduce the power of the pre-heat phase 16 compared to the trigger section 18 .
[0044] Ordinary workers in this field will appreciate that there are an infinite variety of pulse shapes that will satisfy the criteria of a relatively low powered pre-heat section and a subsequent trigger section that nucleates the bubble. Shaping the pulse can be done with pulse width modulation, voltage modulation or a combination of both. However, pulse width modulation is the preferred method of shaping the pulse, being more amenable to CMOS circuit design. It should also be noted that the pulse is not limited to a pre-heat and trigger section only; additional pulse sections may be included for other purposes without negating the benefits of the present invention. Furthermore, the sections need not maintain constant power levels. Constant time averaged power is preferred for the pre-heat section and the trigger section, as that is the simplest case to handle theoretically and experimentally.
[0045] By switching to a higher heating rate after a pre-heat phase the race is won by bubble nucleation because the time lag between different regions of the heater reaching the superheat limit is reduced. FIG. 3 illustrates the concept: even if the spatial temperature uniformity is poor (an unavoidable side effect of low heating rates in the pre-heat phase), the time lag 32 between the hotter and colder regions of the heater reaching the superheat limit can be reduced by switching to a higher heating rate 36 after the pre-heat. In this way, the colder regions reach the superheat limit before they are thermally isolated by bubbles expanding from hotter regions. The majority of the heater surface reaches the superheat limit 34 before significant bubble expansion occurs, so the heater area will be more effectively and consistently utilised for bubble formation.
[0046] FIGS. 4A to 4D demonstrate the effectiveness of shaped pulses in producing large, stable bubbles. The bubble size can be increased tremendously using shaped pulses, without suffering the irregularity shown in FIGS. 1A to 1E . A circuit designer will have a choice of voltage modulation or pulse width modulation of the heating signal to create the shaped pulse, but generally pulse width modulation is considered more suitable to integration with e.g. a CMOS driver circuit. As an example, such a circuit may be used to generate maintenance pulses in an inkjet printhead, where the increased bubble impulse is better able to recover clogged nozzles as part of a printer maintenance cycle. This is discussed in the co-pending application (temporarily referred to by docket number PUA011US), the contents of which are incorporated herein by reference.
[0047] FIG. 5 shows the MEMS bubble generator of the present invention applied to an inkjet printhead. A detailed description of the fabrication and operation of some of the Applicant's thermal printhead IC's is provided in U.S. Ser. No. 11/097,308 and U.S. Ser. No. 11/246,687. In the interests of brevity, the contents of these documents are incorporated herein by reference.
[0048] A single nozzle device 30 is shown in FIG. 5 . It will be appreciated that an array of such nozzles are formed on a supporting wafer substrate 28 using lithographic etching and deposition techniques common within in the field semi-conductor/MEMS fabrication. The chamber 20 holds a quantity of ink. The heater 10 is suspended in the chamber 20 such that it is in electrical contact with the CMOS drive circuitry 22 . Drive pulses generated by the drive circuitry 22 heat the heater 10 to generate a vapour bubble 12 that forces a droplet of ink 24 through the nozzle 26 . Using the drive circuitry 22 to shape the pulse in accordance with the present invention gives the designer a broader range of bubble impulses from a single heater and drive voltage.
[0049] FIGS. 4A to 4D show stroboscopic images of water vapor bubbles in an open pool on a 30 μm×4 μm heater. Like FIGS. 1A to 1E , the bubbles 12 have been captured at their maximum extent. FIG. 4A shows the prior art situation of a simple square profile pulse of 4.2V for 0.7 microseconds. In FIG. 4B , the pulse is shaped by pulse width modulation—a pre-heat series having nine 100 nano-second pulses separated by 150 nano-seconds, followed by a trigger pulse of 300 nano-seconds, all at 4.2V. The bubble size in FIG. 4B is greater because of the amount of thermal energy transferred to the liquid prior to nucleation in the trigger pulse. In FIGS. 4C and 4D , the pulses are voltage modulated. The pulse of FIG. 4C has a pre-heat portion of 2.4V for 8 microseconds, followed by 4V for 0.1 microseconds to trigger nucleation. In contrast, the FIG. 4D pulse has a pre-heat section of 2.25V for 16 microseconds followed by a trigger of 4.2V for 0.15 microseconds. These figures clearly illustrate that bubbles generated using shaped pulses ( FIGS. 4B , 4 C and 4 D) are larger, regular in shape and repeatable.
[0050] With the problem of irregularity or non-repeatability removed, the designer has great flexibility in controlling the bubble size at the design phase or during operation by altering the length of the pre-heat section of the pulse. Care must be given to avoiding accidentally exceeding the superheat limit during the pre-heat section so that nucleation does not occur until the trigger section. If the pulse is pulse width modulated, the modulation should be fast enough to give a reasonable approximation of the temperature rise generated by a constant, reduced voltage. Care must also be given to ensuring the trigger section takes the whole heater above the superheat limit with enough margin to account for system variances, without overdriving to the extent that the heater is damaged. These considerations can be met with routine thermal modelling or experiment with the heater in an open pool of liquid.
[0051] The invention has been described herein by way of example only. Ordinary workers in this field will readily recognise many variations and modifications that do not depart from the spirit and scope of the broad inventive concept. | The invention provides for an inkjet printhead having a plurality of micro-electromechanical vapor bubble generators. Each bubble generator includes a nozzle in fluid communication with an ink chamber, and a heater positioned in thermal contact with ink in the chamber. Each generator also includes drive circuitry configured to provide a modulated pulse to the heater to generate a vapor bubble in the ink in said chamber, the pulse comprising a pre-heat series of a predetermined number of pulses separated by a predetermined period, followed by a trigger pulse of a period twice that of said predetermined period. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent Application No. 102014016570.1, filed Nov. 8, 2014, which is incorporated herein by reference in its entirety.
TECHNICAL HELD
[0002] The present disclosure pertains to a door for a vehicle with an integrated control panel for controlling actuators such as, for example, servomotors of an exterior rearview mirror that are arranged on the door or at other locations of the vehicle.
BACKGROUND
[0003] A vehicle door of this type is known from DE 10 2005 036 001 A1, which addresses the problem of comfortably controlling functionally identical actuators provided in several sets at different locations of the motor vehicle such as, for example, actuators of a left and a right exterior, rearview mirror, power windows or seat adjusters, with a limited number of control elements. In particular, a selection control element is used to select one of several functionally identical actuators, with a control element, by means of which the motions of the respectively selected actuator can be controlled. In this way, one and the same control element can serve for successively controlling different actuators. This is particularly advantageous if the actuator has several degrees of freedom of motion as it is the case with an exterior rearview mirror because the control element for such an actuator is relatively expensive and has a substantial space requirement. However, this conventional concept cannot be used in instances, in which several functionally dissimilar actuators have to be controlled and their potential motions cannot be intuitively associated with the degrees of freedom of the assigned control element.
SUMMARY
[0004] In accordance with the present disclosure, a door for a motor vehicle is provided with an integrated control panel that also enables comfortable control of functionally dissimilar actuators within a confined space.
[0005] According to an embodiment of the present disclosure, a vehicle door features a control panel arranged on the inner side thereof. The control panel is realized in the form of a touchscreen that can be switched over between at least two display modes. The touchscreen displays a first control element for controlling a first actuator of the vehicle in the first display mode and a second control element for controlling a second actuator, which is dissimilar from the first actuator, in the second display mode. The touchscreen makes it possible to respectively realize the different control elements dissimilar such that their potential controls can be intuitively associated with the potential motions of the actuators. The respectively displayed control element furthermore enables the user to ascertain the current display mode of the control panel and whether an actuation of the displayed control element can lead to the desired reaction or the control panel initially needs to be switched over into a different display mode.
[0006] If the number of display modes is small, a selection control element may be additionally displayed in each display mode. This selection control element can be actuated by the user in order to switch into another display mode assigned to the respective selection control element. Alternatively, a selection mode may be provided, in which the control panel displays at least one selection control element for selecting between the first and second display modes.
[0007] The actuators controlled by means of the control panel may fulfill various functions in the motor vehicle. For example, they may control the position of an exterior rearview mirror, a seat or a side window, but they may also open or close a door, a hood or trunk lid or a fuel door of the vehicle, as well as lock and unlock such components in the closed position.
[0008] In the first and the second display modes, a symbol specific to the respectively active display mode should be visible on the touchscreen such that the user can at all times ascertain which actuators can be controlled in the current display mode. In order to select between functionally identical actuators, the touchscreen may in the first display mode display a selection control element, by means of which the first actuator of a plurality of actuators can be selected.
[0009] The touchscreen may be integrally installed into the door. According to an advantageous enhancement, the touchscreen forms part of a mobile device that is removably accommodated in a mount of the vehicle door. Due to its small dimensions on the one hand and its widespread use on the other hand, a smartphone may be considered as such a mobile device.
[0010] Since a broad variety of different models of such devices are in use, the mount should include an exchangeable adapter for accommodating the mobile device in a form-fitting fashion.
[0011] A charging socket for charging a rechargeable battery of the mobile device is well suited for promoting the willingness of the user to place the respective mobile device into the mount. If the mobile device is a mobile telephone, it should be connected to a hands-free speakerphone when it is positioned in the mount. In this way, it can be simultaneously ensured that a user, who uses the telephone while driving, complies with the applicable laws by carrying on the conversation via the hands-free speakerphone.
[0012] The mobile device should be designed for automatically detecting when it is accommodated in the mount. Such a detection may serve different purposes such as, for example, automatically linking the mobile telephone and the hands-free speakerphone. In the context of the present disclosure, the detection of the mobile device being accommodated in the mount particularly should serve to switch the touchscreen into one of the above-described display modes.
[0013] The display mode of the touchscreen may furthermore be switched over in accordance with a state of motion of the vehicle. In this context, particularly a display mode that allows the control of doors, hatches or the fuel door of the vehicle may be blocked while the vehicle is in motion in order to preclude an inadvertent actuation of these elements by the user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements.
[0015] FIG. 1 shows a side view of the lower part of a motor vehicle door;
[0016] FIG. 2 shows a schematic section through a mount for a mobile device;
[0017] FIG. 3 shows a top view of the touchscreen in a selection mode;
[0018] FIG. 4 shows a top view of the touchscreen in a first control mode;
[0019] FIG. 5 shows a top view of the touchscreen in a second control mode;
[0020] FIG. 6 shows a top view of the touchscreen in a third control mode;
[0021] FIG. 7 shows a top view of the touchscreen in a fourth control mode, and
[0022] FIG. 8 shows a top view of the touchscreen in a fifth control mode.
DETAILED DESCRIPTION
[0023] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description.
[0024] FIG. 1 shows the lower part of a door 1 of a motor vehicle, in this case the driver's door, viewed from its inner side. Interior trim panel 2 of plastic conventionally covers large sections of the door panel. An armrest 3 is formed in a central region of the interior trim panel 2 . A handle 5 extends obliquely upward from the horizontal upper side 4 of the armrest 3 . A control panel in the form of a touchscreen 6 is arranged in the upper side 4 at the base of the handle 5 .
[0025] The touchscreen 6 and an assigned control unit may be integrally installed in the door 1 , The control unit acts as display driver for the touchscreen 6 , detects when and where the touchscreen 6 is contacted by a finger of the user and outputs control commands to actuators of the vehicle derived from the finger contact.
[0026] In the example illustrated in FIG. 2 , only a recess 7 , in which an adapter 8 is detachably accommodated, is integrated into the upper side 4 of the armrest. The adapter 8 in turn features a recess 9 that is adapted to the shape of a smartphone 10 placed therein for holding the smartphone in a form-fitting fashion. The touchscreen of the smartphone serves as the above-described touchscreen 6 and its processor serves as the display driver.
[0027] A charging socket 11 of the adapter is coupled to the smartphone 10 in order to connect the smartphone to the vehicle battery and charge its rechargeable battery. The charging socket 11 typically includes a USB connection between the smartphone 10 and other users of an internal network of the vehicle so as to allow data communication there between. When the smartphone is inserted into the recess 9 , for example, such a communication with another user enables the smartphone 10 to detect that it is located in a vehicle, as well as to subsequently establish a link with a hands-free speakerphone of the vehicle on the one hand and to start a utility program described in greater detail below with reference to FIGS. 3-8 on the other hand.
[0028] An edge of the recess 9 located opposite of the charging socket 10 is in this case formed by a latch 13 that is rotatable about an axis 12 extending perpendicular to the plane of section. The latch encompasses the smartphone 10 in a form-fitting fashion in its position illustrated with continuous lines in FIG. 2 and can be pivoted in the clockwise direction about the axis 12 into an orientation illustrated with broken lines, in which the smartphone 10 is lifted out of the recess 9 by an arm 15 of the latch 13 and can be removed by the user, via pressing on an actuating surface 14 .
[0029] When the smartphone 10 is inserted into the recess 9 by the user while the vehicle is at a standstill and the smartphone 10 detects this, for example, based on the communication with another user of the vehicle network via the charging socket 11 , it initiates an application program, in which it can serve as control element for various actuators of the vehicle.
[0030] According to an embodiment, the application program starts with a selection control mode, in which various selection control elements 16 - 19 are defined on the touchscreen 6 as illustrated in FIG. 3 . A user contacting one of these selection control elements 16 - 19 with a finger is respectively interpreted as inputting a selection command. The boundaries of the control elements 16 - 19 , which are illustrated with broken lines in FIG. 3 , do not have to be visible on the touchscreen 6 . However, symbols 20 - 23 are visible within the boundaries of the control elements 16 - 19 and intuitively reveal to the user which actuators can be accessed with the different control elements 16 - 19 . For example, the servomotors of exterior rearview mirrors of the vehicle are indicated with the symbol 20 , power windows with the symbol 21 , servomotors of a seat, typically the driver's seat, with the symbol 22 and a fuel door locking mechanism with the symbol 23 . Other control elements and symbols may serve for locking doors, a hood or trunk lid of the vehicle or, particularly in the case of a trunk lid, for actuating a servomotor that drives the trunk lid motion.
[0031] The link with the on-board network of the vehicle enables the smartphone 10 to detect when the vehicle begins to move. It would be conceivable that individual selection control elements are deactivated when the vehicle is in motion and the symbols assigned thereto preferably are also no longer displayed. This may concern, for example, the control element 19 for the fuel door locking mechanism, which preferably should not be actuatable while the vehicle is in motion. Unlocking or adjusting the hood or trunk lid should also be prevented while the vehicle is in motion.
[0032] When the selection control element 16 is actuated, the touchscreen 6 switches over into a first control mode illustrated in FIG. 4 . The control elements 24 , 25 make it possible to select a left or a right exterior rearview mirror of the vehicle. If applicable, a color change of the corresponding control element 24 or 25 may indicate which of the two exterior rearview mirrors has been selected.
[0033] Four additional control elements 26 are defined at the points of an arrow cross 27 illustrated on the touchscreen 6 . Two opposite control elements 26 control pivoting motions of the respectively selected exterior rearview mirror about one of two pivoting axes in respectively opposite directions. A control element 28 in the center of the arrow cross 27 may be provided for jointly retracting and extending the exterior rearview mirrors.
[0034] A control element 29 may be provided for returning to the selection mode according to FIG. 3 . Alternatively, the return to the selection mode could also take place when no contact of the touchscreen 6 by the user is detected during a predefined waiting or idle period or, for example, a command gesture such as a swiping motion over a large portion of the touchscreen is detected instead of the user tapping on an individual control element.
[0035] A second control mode illustrated in FIG. 5 is activated by actuating the selection control element 17 . Four selection control elements 30 on the corners of the touchscreen 6 are assigned to the four doors of the vehicle and enable the user to specify on which door a power window should be opened or closed by means of large-surface control elements 31 that are centrally positioned on the touchscreen 6 .
[0036] FIG. 6 shows the touchscreen 6 in a control mode that can be selected by means of the selection control element 18 according to FIG. 3 . In this case, control elements 33 , 34 are superimposed on a schematic top view of the driver's seat 32 . The control elements 33 illustrated on the seating surface control a forward or backward motion of the entire seat 32 and the control elements 34 illustrated on the backrest control the inclination of the latter. Although the driver's seat 32 has in this case two degrees of freedom of motion analogous to the exterior rearview mirrors, the arrangement of the control elements 26 illustrated in FIG. 4 would not allow an intuitive control of the driver's seat 32 . The touchscreen 6 makes it possible to always position and, if applicable, combine the control elements with explanatory symbols such as, e.g., 27 or 32 in such a way that an intuitive control can be realized.
[0037] The control mode illustrated in FIG. 7 can only be selected by means of the selection control element 19 when the vehicle is at a standstill. The symbols 36 , 37 , 38 assigned to the control elements 35 in this mode respectively refer to the functions of the corresponding control elements 35 for unlocking a hood, a fuel door or a trunk lid. They may change their appearance depending on the state of actuation, e.g., in that the hood illustrated with broken lines in the symbol 36 is illustrated with continuous lines as soon as the corresponding control element has been actuated and the hood has been unlocked.
[0038] FIG. 8 shows another control mode, in which a schematic top view of the passenger compartment of the vehicle is displayed on the touchscreen 6 . In this case, the illustrations of the doors 39 serve as symbols that mark the position of control elements 40 , by means of which the respective locking mechanism of the corresponding door is controlled. Another control element 41 may be superimposed on the illustration of the rear seats in order to activate and deactivate a child safety lock on the rear doors.
[0039] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents. | A control panel realized in the form of a touchscreen is arranged on an inner side of a vehicle door. The control panel can be switched over between at least two display modes. The touchscreen displays a first control element for controlling a first actuator of the vehicle in the first control mode and a second control element for controlling a second actuator, which is dissimilar from the first actuator, in the second control mode. The control panel may include a touchscreen of a smartphone device operably positioned in a recess formed in qn interior trim panel of the vehicle door. | 1 |
FIELD OF THE INVENTION
The present invention relates to a method for producing a synthetic quartz glass for use in the optical system of a lithographic exposure system equipped with excimer laser radiation as a light source. More particularly, the present invention relates to a method for producing a synthetic quartz glass for use in the illumination systems and projection systems of an ArF excimer laser lithographic exposure system, such as a lens, a prism, and a beam splitter.
BACKGROUND OF THE INVENTION
Recently, the patterns of integrated circuits produced on a wafer have become finer with the increasing degree of integration in LSIs; furthermore, mass production of super LSIs having super-fine patterns of quarter micrometers (0.25 μm) or less in fineness is now under way. To obtain such super-fine patterns, it is also necessary to use exposure light sources having a shorter wavelength, and steppers using excimer laser radiation as the light source have been developed. The steppers equipped with KrF excimer laser radiation (248 nm in wavelength) as the light source have already been put to practical use. Furthermore, steppers equipped with ArF excimer laser radiation (193 nm in wavelength) as the light source are attracting much attention as a promising stepper of the next generation. As a glass material which exhibits sufficiently high transmittance in the short wavelength region of the KrF excimer laser and ArF excimer laser radiations, there can be mentioned a quartz glass, fluorite, etc. Particularly among them, a synthetic quartz glass prepared by fusion and vitrification of a product obtained by flame hydrolysis of a high purity silicon compound and the like is preferred as an optical material for lithography using excimer laser radiation as the light source, because it exhibits high transmittance in the short wavelength region of 260 nm or less.
In the case of employing the synthetic quartz glass mentioned above as an optical materials for use in lithography using excimer laser radiation as the light source, and particularly, in the case of using ArF excimer laser radiation, it is required that the glass has an internal transmittance of approximately 99.8% for a light 193 nm in wavelength, and that it is highly homogeneous so that it provides excellent imaging properties, as described in Japanese Patent Laid-Open No. 53432/1998. The homogeneity of a synthetic quartz glass is generally achieved by applying a homogenization treatment to a synthetic quartz glass ingot obtained by fusion and vitrification of a product obtained by flame hydrolysis of a high purity silicon compound and the like. However, because the synthetic quartz glass ingot is exposed for a long period of time at high temperatures in the homogenization treatment, there occurs contamination due to the impurities generated from the refractories such as alumina, zirconia, graphite, etc., which constitute the furnace material. The loss of transmittance due to the contamination is found particularly noticeable in the case where ArF excimer laser radiation is used; thus, it is unfeasible to use the synthetic quartz glass impaired in transmittance due to this contamination as the optical materials for steppers employing an ArF excimer laser as the light source.
Accordingly, the present inventors proposed a method for recovering the loss in transmittance of a synthetic quartz glass contaminated by the aforementioned homogenization treatment in Japanese Patent Application No. 2762188. In accordance with the method described in that Japanese Patent Application, it has been found that the transmittance for ArF excimer laser radiation is recovered, and that the internal transmittance for a light having a wavelength of 193 nm is recovered to about 99.8%. However, the products thus obtained were not always the same, and it was hence difficult to maintain a stable production of synthetic quartz glass for use in ArF excimer laser lithography. On the other hand, in Japanese Patent Laid-Open No. 53432/1998, there is proposed a synthetic quartz glass for use in ArF excimer laser lithography, which is obtained by a method comprising achieving homogeneous refractive index during synthesis and without applying secondary heating treatment such as homogenization, because several parts per billion of Na are mixed into the glass during the secondary heat treatment. The synthetic quartz glass described in Japanese Patent Laid-Open No. 53432/1998 has an Na concentration of 20 ppb or less, and if the Na concentration is more than 20 ppb, 5 to 100 ppb of Al is required to be contained (see paragraphs [0017] to [0019]. However, because a synthetic quartz glass is produced by depositing silica soot which is generated by flame hydrolysis of silane used as the starting material, followed by fusion and vitrification, superior homogeneity within the plane vertical to the direction of growth of the synthetic quartz glass (i.e., the longitudinal direction) can be readily achieved, however, it is technologically extremely difficult to increase the homogeneity in the direction parallel with the direction of growth (i.e., the lateral direction), because the stripes that generate with the growth, i.e., the so-called layers or layer-structure, are formed in this direction. Furthermore, the production method described in the unexamined published Japanese Patent Application mentioned above makes the apparatus very complicated and expensive, because it requires, in addition to the rotation of the target plate, operations such as vibrating and pulling down as well as the operation of maintaining the synthetic plane and the burner apart from each other at a constant distance. Moreover, the diffusion constant of Al in quartz glass is as small as 1×10 −13 cm 2 /sec, which is extremely lower than the diffusion constant of Na, i.e., 7.9×10 −6 cm 2 /sec (refer to “Handbook of Glass Properties” (Academic Press)). Thus, it is technologically difficult to homogeneously dope both Al and Na which greatly differ from each other in diffusion constants.
In light of the aforementioned circumstances, extensive studies were conducted on the development of synthetic quartz glass for use in ArF excimer laser lithography having high homogeneity and high transmittance. As a result, it has been found that the production method proposed in Japanese Patent No. 2762188 is most suitable from the viewpoint of its ease in carrying out and its low cost. Further studies have been performed on that production method. It has now been found that the fluctuation of the product quality is attributable to the concentration of Na contained in the synthetic quartz glass, and that by specifying the range of Na concentration and by irradiating at an ultraviolet radiation 260 nm or shorter in wavelength at a specified luminance and for a specified time duration, it is possible to maintain a stable production of a synthetic quartz glass having high homogeneity and yet high transmittance for an ArF excimer laser radiation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for maintaining stable production of a synthetic quartz glass for ArF excimer lasers, which has an excellent homogeneity and high transmittance of ArF excimer laser radiation.
It is an object of the present invention to provide a simple method for producing a synthetic quartz glass having excellent homogeneity and high transmittance, which is useful as an optical material in producing steppers equipped with an ArF excimer laser as a radiation source.
These objects and others that will become apparent from the following specification are achieved by providing a method for producing a synthetic quartz glass for use in ArF excimer laser lithography, which comprises irradiating a highly homogeneous synthetic quartz glass containing less than 60 ppb of Na with an ultraviolet radiation having a wavelength of 260 nm or less for not less than the time duration expressed by the following equation 2
Y =(80 X −1880)/ Z
wherein X represents an Na concentration (ppb), Y represents the time duration of irradiation (hours) and Z represents the illuminance of ultraviolet radiation on an irradiated surface (mW/cm 2 ).
In the present invention, the term “having high homogeneity” signifies a state in which the refraction index distribution within the optical plane (clear aperture) is controlled to be 2×10 −5 or less and the striae in three directions and the internal stress are removed, which is obtained by subjecting a high purity silicon compound to flame hydrolysis, obtaining therefrom a synthetic quartz glass ingot by fusion and vitrification, and subjecting the resulting ingot to either homogenization treatment or homogenization treatment followed by molding and stress removal (referred to hereinafter as homogenization treatment and the like). The synthetic quartz glass is produced by either direct method comprising depositing a soot produced by flame hydrolysis of a high purity silicon compound such as silicon tetrachloride, methyl trimethoxysilane, tetramethoxysilane, etc., on a target, while simultaneously fusing it and vitrifying, or by a soot method comprising depositing the soot on a target, and then vitrifying it by heating and fusing in an electric furnace. As the homogenization treatment above, there can be mentioned a method which comprises subjecting the synthetic quartz glass ingot to a heat treatment at 2000° C. for a long duration of time in a refractory furnace or a method of zone melting the synthetic quartz glass, etc. However, preferred is a method of zone melting described in Japanese Patent Laid-Open No. 267662/1995 (referred to hereinafter as the zone melting method), which comprises zone melting a synthetic quartz glass ingot by supporting both ends in the longitudinal direction of the synthetic quartz glass ingot with a supporting member and rotating the ingot around the axis connecting the support ends; deforming the ingot into a shape protruding outward in the zone melting region by applying pressure in the direction of the supporting axis, thereby producing a synthetic quartz glass ingot having low optical homogeneity in the direction perpendicular to the direction of optical homogeneity along the direction of supporting axis; and after supporting the ingot by the side planes above using a support, applying thereto homogenization treatment similar to above.
The synthetic quartz glass subjected to the homogenization treatment and the like is then subjected to the irradiation of ultraviolet radiation. However, a preferred synthetic quartz glass is a synthetic quartz glass molding subjected to homogenization treatment, molding, and stress-removal treatment. The “molding” referred above is a process which comprises forming the synthetic quartz glass to a shape such as a cube, disk, pyramid, etc., which is required for an optical material, and the “stress-removal treatment” is a process which comprises removing internal stress of the synthetic quartz glass. Because the homogenization treatment and the like are performed in a refractory furnace or in a heat-resistant furnace, contamination is generated due to the impurities from the furnace material. In particular, the contamination of Na is a serious problem, because the presence of Na in the synthetic quartz glass generates an absorption band around a wavelength of 180 nm thereby greatly reducing the transmittance of ArF excimer laser radiation. It has been found that a homogenization treatment performed at a temperature of 2000° C. incorporates 30 ppb or more of Na, whereas each of the molding and the stress-removal treatment steps incorporates from 5 to 10 ppb of Na. However, in the zone melting method, the synthetic quartz glass ingot is less contaminated, because it is not brought into contact with the furnace material and the jigs, and the Na content is as low as about 20 ppb, and even after molding, the content can be suppressed to about 24 ppb. On the other hand, if the Na content exceeds 60 ppb, as is shown in FIG. 1, the recovery on irradiating with ultraviolet radiation of 260 nm or shorter in wavelength the results are insufficient, and the internal transmittance for a light 193 nm in wavelength cannot be recovered to about 99.8%. Accordingly, it is requisite that the Na content in the synthetic quartz glass subjected to the ultraviolet irradiation treatment according to the present invention is in a range of from 20 to 60 ppb.
For the ultraviolet radiation of 260 nm or less in wavelength, particularly preferred is a continuous light, and the ultraviolet radiation should be conducted for a time duration expressed by the general equation 3:
Y =(80 X −1880)/ Z
wherein X represents an Na concentration (ppb), Y represents the time duration of irradiation (hours), and Z represents the illuminance of the ultraviolet radiation on an irradiated surface (mW/cm 2 ).
Even though the Na content should be in a range of from 20 to 60 ppb, as is shown in FIG. 2, preferably in the range of from 24 to 60 ppb, the internal transmittance of the synthetic quartz glass cannot be recovered to the allowable limit of about 99.8% if the duration of the irradiation is less than the range satisfying the general equation 3 above. Furthermore, even if the duration and the luminance should satisfy the general equation 3 above, the internal transmittance for a light 193 nm in wavelength cannot be recovered to about 99.8% if the Na concentration in synthetic quartz glass is not in the range of from 20 to 60 ppb. In FIG. 2 above, it can be seen that there is a relation expressed by general equation 3 among X, Y, and Z from the linear regression, where X represents the Na content (ppb), Y represents the duration of irradiation (hour), and Z represents the illuminance of ultraviolet radiation on an irradiated surface (mW/cm 2 ). Furthermore, it is clear from Table 3 that the time duration of irradiation is inversely proportional to the illuminance. As a lamp for use in the ultraviolet irradiation mentioned above, there may be used a low vapor pressure mercury lamp having the principal wavelengths 253.7 nm and 184.9 nm, an Xe excimer lamp having a wavelength of 172 nm, or a KrCl excimer lamp have a wavelength of 222 nm. Furthermore, the surface roughness R max of the synthetic quartz glass which has been irradiated by ultraviolet radiation is preferably 30 μm, or less. If the surface roughness Rmax should exceed 30 μm, the scattering of ultraviolet radiation increases so as to make it difficult to improve the effect of the treatment. Furthermore, the illuminance of the ultraviolet radiation should be at least 1 mW/cm 2 . The recovery of the internal transmittance is possible even if the time duration of irradiation is elongated. However, because the life of an ultraviolet lamp is generally short, it requires an increase not only in the use of the lamp, but also in the amount of electric power and gaseous nitrogen so as to lead to an increase in cost. Yet, not much can be expected in the improvement of the irradiation effect, thus, up to twice the time duration expressed by the general equation 3 is acceptable.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing the relation between the duration of irradiation with an ultraviolet radiation in hours and the internal transmittance in %.
FIG. 2 is a graph showing the relation between Na concentration in ppb which provides an internal transmittance of 99.8% and the duration of irradiation with an ultraviolet radiation (hours).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described in further detail below by referring to Examples, but it should be understood that the present invention is not limited thereto.
The physical properties in the Examples and Comparative Examples below are values obtained by the following methods of measurement:
i) Distribution of Refractive indices: Measurement method using a Fizeau interferometer.
ii) Birefringence: Measurement method using crossed nicols.
iii) Striae: Visula observation.
iv) Internal transmittance at 193 nm: A measurement method using a value of 90.68% obtained by subtracting 0.18% (a known value of loss in Rayleigh scattering) from the theoretical transmittance 90.86% of quartz glass for light of 193 nm in wavelength; the value is obtained in accordance with (T/90.68)×100, that is, it is obtained with respect to an apparent transmittance of T % at a thickness of 10 mm.
v) Na concentration: Measurement method using flame-less atomic absorption analysis.
EXAMPLE 1
A high purity methyl trimethoxysilane was introduced into an oxyhydrogen flame, was molten and deposited on a rotating base body to prepare a synthetic quartz glass ingot having an outer diameter of 100 mm and a length of 600 mm. Both ends of the resulting ingot were welded to the quartz glass supporting rods clamped by the chucks of a lathe for processing quartz glass to rotate the synthetic glass ingot. The rotating ingot was locally heated by a burner to form a melting zone, and by independently changing the direction and the speed of rotation, strain was generated in the melting zone to remove the striae from the ingot and to perform homogenization thereon. Then, by narrowing the distance between the chucks of the lathe for processing the quartz glass, pressure was applied to the synthetic quartz glass ingot to deform it into a spherical synthetic quartz glass, and the spherical synthetic quartz glass was cut out. The cut synthetic quartz glass was homogenized again by attaching it to the supporting rod on the supporting table in such a manner that the cut planes were on the upper and the lower sides thereof, and by heating and softening it using a burner while applying rotation thereto. The ingot thus obtained was found to be free of any striae in its three dimensions. For the molding described above, a graphite crucible having 20 ppm or less of ash content was used; the inside of the crucible was first replaced with gaseous nitrogen, and the temperature therein was elevated to 1900° C. and was maintained at that temperature for 10 minutes to obtain a molding. The resulting quartz glass molding having an outer diameter of 200 mm and a thickness of 135 mm was placed inside an electric furnace using 99% or higher purity alumina as the furnace material, and after keeping it at 1150° C. for a period of 50 hours, gradual cooling at a rate of 5° C./hour was applied thereto until the temperature was lowered to 600° C. Then, the product was subjected to natural cooling to perform the stress-removal treatment. After measuring the optical properties of the synthetic quartz glass molding thus obtained, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm (Sample A) and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform the measurement of transmittance and purity analysis. The results are given in Table 1.
TABLE 1
Internal
Na
Chlorine
Δn, in
Δn,
Striae
Birefrin-
transmit
concen-
concen-
optical
lateral
lateral
gence
tance at
tration
tration
Sample
plane
direction
direction
nm/cm
193 nm
(ppb)
(ppm)
A
1 × 10 −6
4 × 10 −6
None
<1
99.62%
40
0
B
2 × 10 −6
4 × 10 −6
None
1
99.55%
47
0
C
1 × 10 −6
3 × 10 −6
None
<1
99.48%
55
0
D
1 × 10 −6
4 × 10 −6
None
1
99.36%
40
20
E
1 × 10 −6
3 × 10 −6
None
<1
99.77%
26
0
F
2 × 10 −5
4 × 10 −5
Present
20
99.89%
2
0
G
1 × 10 −5
3 × 10 −5
Present
1
99.89%
12
0
H
2 × 10 −6
4 × 10 −6
None
1
99.15%
89
0
I
2 × 10 −5
4 × 10 −6
None
<1
99.08%
97
0
EXAMPLE 2
A synthetic quartz glass molding was prepared by an operation similar to that described in Example 1, except for changing the duration of molding to 30 minutes. After obtaining the optical properties of the resulting synthetic quartz glass molding, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm (Sample B) and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform the measurement of transmittance and purity analysis. The results are given in Table 1.
EXAMPLE 3
A synthetic quartz glass molding was prepared by an operation similar to that described in Example 1, except for maintaining the synthetic quartz glass molding at 1150° C. for a period of 50 hours and cooling gradually thereafter to 600° C. at a cooling rate of2° C./hour. After obtaining the optical properties of the resulting molding, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm (Sample C) and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform the measurement of transmittance and purity analysis. The results are given in Table 1.
EXAMPLE 4
A high purity silicon tetrachloride was introduced into an oxyhydrogen flame, and was melted and deposited on a rotating base body to prepare a synthetic quartz glass ingot having an outer diameter of 100 mm and a length of 600 mm. After applying homogenization treatment, molding, and stress-removal treatment similar to those described in Example 1 to the resulting synthetic quartz glass ingot, and obtaining the optical properties thereof, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm (Sample D) and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform the measurement of transmittance and purity analysis. The results are given in Table 1.
EXAMPLE 5
A synthetic quartz glass molding was prepared by an operation similar to that described in Example 1, except that the molding was performed by elevating the temperature to 1900° C., and then, without holding at the temperature, gradually cooling to 600° C. at a cooling rate of 5° C./hr. After obtaining the optical properties of the resulting synthetic quartz glass molding, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm (Sample E) and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform the measurement of transmittance and purity analysis. The results are given in Table 1.
Comparative Example 1
The synthetic quartz glass ingot (Sample F) prepared in Example 1 was set inside a graphite crucible having an inner diameter of 200 mm and an ash content of 20 ppm or less without applying thereto the homogenization treatment, and the entire graphite crucible was maintained inside a nitrogen-purged crucible at 1900° C. for a duration of 10 minutes to obtain a synthetic quartz glass molding having an outer diameter of 200 mm and a thickness of 135 mm. The resulting synthetic quartz glass molding was set inside an electric furnace made of alumina 99% or higher in purity as the furnace material, and after maintaining it at 1150° C. for a period of 50 hours, it was gradually cooled to 600° C. at a cooling rate of 5° C./hr and further subjected to natural cooling to perform the stress-removal operation. After obtaining the optical properties of the resulting molding, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm (Sample G) and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform the measurement of transmittance and purity analysis. The results are given in Table 1.
Comparative Example 2
A synthetic quartz glass molding was prepared by an operation similar to that described in Example 1, except for using a graphite crucible having an ash content of 50 ppb for the molding. After obtaining the optical properties of the resulting molding, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm (Sample H) and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform the measurement of transmittance and purity analysis. The results are given in Table 1.
Comparative Example 3
A synthetic quartz glass molding was prepared by an operation similar to that described in Example 3, except for using an alumina furnace material having a purity of 90% as the furnace material of the heating furnace used for the stress-removal operation. After obtaining the optical properties of the resulting molding, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm (Sample 1) and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform the measurement of transmittance and purity analysis. The results are given in Table 1.
For samples A to E and G to I above, Table 2 gives the duration of continuously irradiating with ultraviolet radiation 260 nm or shorter in wavelength at an illuminance of 20 mW/cm 2 and the change in internal transmittance at 193 nm.
TABLE 2
Sample
0 hrs
24 hrs
48 hrs
72 hrs
A
99.62%
99.71%
99.74%
99.82%
B
99.55%
99.63%
99.70%
99.77%
C
99.48%
99.58%
99.64%
99.68%
D
99.36%
99.43%
99.53%
99.62%
E
99.77%
99.85%
99.88%
99.90%
G
99.89%
99.90%
99.91%
99.92%
H
99.15%
99.25%
99.31%
99.33%
I
99.08%
99.20%
99.23%
99.27%
From Tables 1 and 2 above, it is clear that the Samples A to E having Na Concentration in a range of from 25 to 60 ppb recovers the internal transmittance thereof to about 99.8%, but that the Samples H and I, whose Na concentration exceeds 60 ppb, the internal transmittance remains a value of 99.4% or lower even after irradiation is applied for a duration of 72 hours.
EXAMPLE 6
From the synthetic quartz glass molding of Example 1 subjected to homogenization treatment, a sample for measuring the transmittance having an outer diameter of 60 mm and a thickness of 10 mm and a fraction for use in chemical analysis were extracted from the inner side 20 mm in depth from the surface of the resulting synthetic quartz glass molding to perform continuous ultraviolet radiation 260 nm or shorter in wavelength at an illuminance of 10 mW/cm 2 . The time duration of irradiation and the change in internal transmittance at 193 nm are given in Table 3.
EXAMPLE 7
The same procedure as described in Example 6 was performed except for changing the illuminance to 7 mW/cm 2 , and the duration of irradiation and the change in internal transmittance at 193 nm were obtained. The results are given in Table 3.
TABLE 3
Illuminance
Internal transmittance for 193-nm light
mW/cm 2
0 hrs
48 hrs
96 hrs
144 hrs
10
99.61%
99.71%
99.77%
99.79%
7
99.62%
99.67%
99.72%
99.74%
From Table 3 above, it can be clearly seen that the duration of irradiation necessary to recover an internal transmittance for a 193-nm light to about 99.8% is inversely proportional to the illuminance.
The foregoing specification and drawings have thus described and illustrated a novel method for producing synthetic quartz glass for use in ArF excimer laser lithography. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification which discloses the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow. | A simple method for producing a synthetic quartz glass having excellent homogeneity and high transmittance, which is useful as an optical material in producing steppers equipped with an ArF excimer laser as a radiation source. A method for producing a synthetic quartz glass for use in ArF excimer laser lithography, which comprises irradiating a highly homogeneous synthetic quartz glass containing less than 60 ppb of Na with ultraviolet radiation having a maximum wavelength of 260 nm for not less than the duration expressed by the equation:
Y =(80 X −1880)/ Z
wherein X represents an Na concentration (ppb), Y represents the duration of irradiation (hours), and Z represents the illuminance of an ultraviolet radiation on an irradiated surface (mW/cm 2 ). | 2 |
RELATED APPLICATIONS
[0001] This application claims priority from Tao CHENG, provisional patent application Ser. No. 60/514,329 (filed 24 Oct. 2003), and from Tao CHENG, provisional patent application serial no. 60/______ (filed 19 Oct. 2004), the contents of which are incorporated by reference here.
GOVERNMENT INTEREST
[0002] Certain claims of this application may have been reduced to practice using National Institutes of Health grant numbers DK02761-01 and/or HL70561.
BACKGROUND
[0003] Stem cells (for example, hematopoietic stems cells, or “HSCs”) provide many potential therapeutic uses in vivo. Stem cells' ability to differentiate into a variety of mature cell types indicates that undifferentiated stem cells may be clinically useful, for example, in treating disease both malignant (e.g., chronic myelogenous leukemia, acute myelogenous leukemia) and non-malignant (e.g., severe aplastic anemia, inherited metabolic disorders). A problem in using human stem cells in vivo, however, is that while stem cells may differentiate into a variety of mature cell types, the lifespan of a specific human stern-cell cell culture is limited by the cell line's ability to “self-renew” or propagate new undifferentiated stem cells (called “self-renewal”). Thus, the art has sought a way to increase the lifespan of human stem cell cultures or cell lines, by increasing self-renewal.
SUMMARY
[0004] I have found a way to increase human-compatible stem cell self-renewal. My invention involves reducing or eliminating the presence of the protein “p18” in the undifferentiated stem cell culture. This may be done, for example, by downregulating expression of the p18 gene, or by attacking the p18 polypeptide with an enzyme or chemical.
[0005] The protein “p18” (p18 INK4C , INK4C, Cdlcn2c) is known in the art. See e.g., H. HIRAI et al., “Novel INK4 proteins, p19 and p18, are specific inhibitors of the cyclin D-dependent kinases CDK4 and CDK6”, 15(5) M OL . C ELL . B IOL. 2672 (1995) (disclosing primary amino acid sequence of mouse p18); K. L. GUAN et al., “Growth suppression by p18, a p16INK4/MTS1- and p14INK4B/MTS2-related CDK6 inhibitor, correlates with wild-type pRb function,” 8(24) G ENES D EV. 2939 (1994) (disclosing primary amino acid sequence of human p18). p18 is a cyclin-dependent kinase inhibitor (CKI). P18 is an INK4 family protein. It acts at the early G1-phase of the cell cycle.
[0006] p18 has a unique role in inhibiting self-renewal of hematopoietic stem cells (HSCs) in vivo. Increased stem cell self-renewal might be readily achieved in vitro due to the absence of p18. To demonstrate this, we first performed the Dexter long-term culture of bone marrow cells. This enumerates the cobble stone area-forming cell (CAFC). This is an in vitro surrogate for murine HSC.
[0007] There was no difference of CAFC yield in the first 4 weeks of the long-term culture between p18−/− (the genotype for cells lacing the p18 gene) and p18+/+ flasks. However, significantly more CAFCs were constantly generated in p18−/− than in p18+/+ flasks (p<0.01, n=4) from 6 weeks to 19 months after the initial culture. Strikingly, the frequency of CAFC at week 19 in p18−/− culture was still equivalent to its level at week 5, whereas the p18+/+ culture nearly lost its ability of producing CAFCs at week 19. In addition, the higher production of CAFCs in p18−/− culture was also associated with a higher production of non-adherent cells, which were dominated by differentiated cells in myeloid lineage.
[0008] This hints that the difference was due to the intrinsic deficiency of p18 in HSCs, but does not confirm it. To confirm it, irradiated stromal cells from wild type bone marrow were used instead in the long-term culture with limiting dilution of the input cells from p18−/− or p18+/+ marrow. Using these cells, there was 2-fold increase of CAFC frequency (week 5-6) in p18−/− plates compared to the p18+/+ plates.
[0009] To further assess HSC proliferation in a defined population, we examined in vitro cell divisions of the highly purified HSCs, namely the CD34 − Lin − c-Kit + Sca-1 + (CD34 − LKS) cells. The repopulating ability of the sorted CD34 − LKS cells (CD45.2) was validated by the limiting dilution assay for competitive repopulating unit (CRU) in the congenic (CD45.1) mice. Three months after transplantation, we were able to determine approximately one CRU in 20 CD34 − LKS cells from p18+/+ marrow and one CRU in 10 CD34 − LKS cells from the p18−/− marrow examined. Single CD34 − LKS cells were deposited to Terasaki plates (one cell/well) and cultured in serum free medium supplemented with SCF, Flt3L and TPO. While most cells entered cell cycle within 3 days, which was in agreement with previous studies by others, surprisingly, there was no significant difference of the rate of cell division between p18−/− and p18+/+ CD34 − LKS cells (>100 cells/experiment, 5 experiments).
[0010] This indicates that p18 deficiency does not increase the proliferative rate of HSC. Rather. P18 deficiency may modulate the fate-choice of HSC toward symmetric cell divisions. To directly test this hypothesis, single CD34-KSL cells were cultured for two days and paired daughter cells along with minimal Sca-1 depleted competitor cells (CD45.1/2 F1) were separately transplanted into different recipients. Positive engraftment was found in the single daughter HSC transplanted mice.
[0011] Together, these findings suggest that p18 deficiency favors symmetric divisions in the compartment of HSC though a cell-cycle independent manner. Down modulating p18 may pen-nit enhanced stem cell expansion in vitro, a method that can be used in stem cell expansion and in defining other active agents for stem cell expansion. Given the nonspecific expression of p18 in hematopoietic cells, this approach can also be applied to other stem cell types in the body.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 shows preferential outgrowth of p18−/− hematopoietic cells, as compared to p18+/+ cells), during long-term engraftment after primary competitive bone-marrow transplant (“CBMT”).
[0013] FIG. 2 shows sustained multipotentiality and dominance of the regenerated p18−/− hematopoietic stem cells (“HSC”s) after secondary competitive bone marrow transplant.
[0014] FIG. 3 shows enlarged pool size of HSCs in p18−/− mice under steady-state conditions and enhanced regeneration of p18−/− HSCs following the HSC transplantation.
[0015] FIG. 4 shows direct demonstration of increased divisions of the p18 −/− HSCs in vivo.
[0016] FIG. 5 shows graphs measuring BrdU incorporation into cell types having three different maturities in vivo (undifferentiated stem cells, intermediate cells and fully-differentiated cells).
[0017] FIGS. 6, 7 and 8 show proliferative rates of the single stem or progenitor cell in vitro. Together with FIG. 5 , these data support the notion that symmetric stem cell divisions but not the non-specific increase of cell proliferation can be promoted by deleting p18 protein.
[0018] FIG. 9 shows the selective expansion of cobblestone area forming cells (“CAFC”) (an in vitro surrogate assay for stem cells) during long-term culture. Based on the in vivo data ( FIG. 1-5 ), down-modulating p18 may permit enhanced stem cell expansion in vitro, a hypothesis that has been tested in our laboratory with this data together with the data in FIG. 10 below.
[0019] FIG. 10 shows the long-term engraftment of the p18−/− stem cells after 19 weeks in vitro. To further demonstrate the in vivo reconstituting ability of cells that had been cultured under the Dexter culture condition for 19 weeks ( FIG. 9 ), 2-20×10 5 cells with non-adherent and adherent populations were transplanted into lethally irradiated hosts. Three of 7 mice revealed long-term engraftment in the p18−/− transplanted group (0.5-33% engraftment levels); while there was no engraftment in the p18+/+ group (n=7). Moreover, a substantial level (38.6% on average) of long-term engraftments (0.7 months) in multilineage was achieved in secondary recipients transplanted with the p18−/− cells (n=3), demonstrating the self-renewal potential of the expanded HSCs after the extended period of long-term culture. The green fluorescent protein (GFP) positive cells are the cells that have been transplanted into the recipients. These data strongly indicate that p18 absence is able to substantially mitigate the differentiating effect of the ex vivo culture conditions on HSCs, and therefore offer a strong rationale for targeting p18 in human HSC expansion.
[0020] FIG. 11 shows gene expression of p18 in human hematopoietic stem cells by RT PCR method. M: molecular weight markers; 1-2: two duplicate samples of human stem cells from cord blood; 3: positive control from Hela cells; 4: negative control—no RT enzyme; 5: negative control—no mRNA template.
[0021] FIG. 12 shows that p18 protein in human stem cells can be substantially reduced by p18 RNA interference technique. FIG. 12 a shows a Western analysis for p18 protein. NS: negative control with non-specific RNA oligos; p18 siRNA: cells treated with a specific sequence of p18 small interfering RNA oligos; NT: negative control without treatment. FIG. 12 b shows a summary of multiple experiments, showing 70% of p18 protein can be removed by p18 siRNA in two days.
[0022] FIG. 13 shows the feasibility of delivering siRNA oligos into human stem cells by a high efficiency electroporation method. A & C: control cells without the electroporation method, B & D: test cells with p18 siRNA oligos conjugated with green fluorescence delivered by an optimized electroporation method. The upper panel is the direct visualization under a microscope, and the lower panel is the quantitative analysis by flow cytometry.
[0023] FIG. 14 shows a successful example of delivering p18 siRNA into human stem cells by an alternative lentiviral method. The green color is an indicator for the p18 siRNA presence in the cells.
[0024] FIG. 15 shows a schematic experimental procedure for testing human stem cells deficient in p18 with an in vivo model.
[0025] FIG. 16 shows the experimental procedure for competitive bone marrow transplantation (cBMT) coupled with serial transfer as extensively used in FIGS. 1 and 2 .
[0026] FIG. 17 shows the procedure of isolating the hematopoietic stem cells by immuno-staining and flow cytometry cell sorter.
[0027] FIG. 18 shows the assay for vigorously testing the stem cell function, namely the competitive repopulation unit (CRU).
DETAILED DESCRIPTION
[0028] Stem cells in vivo have a unique ability to reproduce themselves (self-renewal or self-regeneration) in physiologically determined balance with differentiation or cell death. Cell cycle regulation is one of the fundamental mechanisms underlying cell fate determination. Emerging data indicate that cell cycle status per se is a critical determinant of stem or progenitor cell function, but molecular events orchestrating these deterministic roles are largely undefined. In mammalian cells, entry into the cell cycle requires sequential activation of the cyclin-dependent kinases (CDK) 4/6 and CDK2, which are inhibited by the INK4 proteins (p16 INK4A , p15 INK4B , p18 INK4C , and p19 INK4D ) and the Cip/Kip proteins (p21 Cip1/Waf1 , p27 kip1 and p57 Kip2 ), respectively.
[0029] Both INK4 and Cip/Kip families compose an important class of cell cycle inhibitors, termed CDK inhibitors (CKIs). While a complex array of extracellular signals and intracellular transduction pathways participate in communicating cell cycle regulatory cues, CKIs appear to be critical mediators of cell cycle control that may function in a cell autonomous manner. As previously shown in murine hematopoietic cells, p21 deficiency resulted in an enlarged hematopoietic stem cell (HSC) pool under homeostasis, but stem cell function was compromised in stress conditions. Given that the two CKI families target distinct components in the cell cycle machinery, we hypothesized that the INK4 proteins functioning earlier in G1 may influence the fate of stem cell division upon mitogenic stimuli in a unique manner. This hypothesis was indirectly supported by recent studies indicating p16 INK4A and p19 ARF as downstream mediators of the Bmi-1 protein regulating HSC self-renewal. The distinct INK4 family member p18 INK4C is expressed in multiple tissue types including hematopoietic cells, the loss of which in mice results in organomegaly with higher cellularity and increases the incidence of tumorigenesis with advanced age or in the presence of carcinogens. We now report an inhibitory role of p18 in HSC self-renewal through the use of reconstituted mice with p18 deficient hematopoietic cells and extensive in vivo evaluation of stem cell function.
[0030] Hematopoietic stem cells are responsible for long-term hematopoietic reconstitution of irradiated mice and their functions can be definitively examined in transplant models. We first took the approach of competitive bone marrow transplantation to directly assess the possible impact of p18 absence on hematopoietic reconstitution. Our data is shown in FIG. 1 .
[0031] FIG. 16 shows a schematic diagram of “Competitive and Serial Bone Marrow Transplantation.” The competitive bone marrow transplantation (“CBMT”) is performed repeatedly (serially).
[0032] In FIG. 16 , equal numbers (2×10 6 ) of bone marrow nucleated cells from p18+/+ mice and p18−/− mice were co-transplanted into lethally irradiated recipients. The relative contribution from each genotype was quantified with a semi-quantitative PCR approach. Based on the standardization simultaneously generated under identical PCR conditions (see FIG. 1 a ), p18−/− blood cells constituted 93.3% (vs. 6.7% of p18+/+ genotype on average) in the mixed populations. Therefore, there was on average a 14-fold greater abundance of the long term repopulating ability (LTRA) in p18−/− bone marrow cells compared with the same number of p18+/+ marrow cells.
[0033] To determine whether the increased engraftment of the p18 −/− genotype cells occurred at the HSC or the hematopoietic progenitor cell (HPC) level, quantitative assays for colony forming cell (CFC) (in vitro surrogate for HPC) and long-term culture initiating cell (LTC-IC) (in vitro surrogate for HSC), were performed with subsequent colony genotypic analyses by PCR. Dramatic overrepresentation of the p18−/− genotype was observed in both the CFC and LTC-IC pools. This data is shown in Table 1.
TABLE 1 Follow-up of p18−/− genotype in individual stem/progenitor cells after CBMT A B C D E F G Primary Exp. 1 CFC 10 3 39 38 1 97.5 CBMT Exp. 2 CFC 7 3 122 115 7 94.3 10 3 108 107 1 99.1 14 3 144 143 1 99.3 LTC-IC 10 3 48 45 3 93.7 Exp. 3 CFC 8 3 85 72 13 80.0* 12 3 122 110 12 90.1* LKS 12 2 220 201 19 91.4 Secondary CD34 − 12 or 3 109 101 8 92.7 CBMT** LKS 22*** Legend: Column A: Clonal Culture Column B: Months After Bone Marrow Transplant Column C: Number of mice analyzed Column D: Total number of colonies analyzed Column E: Total number of p18−/− colonies shown Column F: Total number of p18+/+ colonies shown Column G: p18−/− dominance (as a percentage of the total colonies shown)
In addition, we found that 91.4% of the Lin − c-kit + Sca-1 + cells (LKS) (an in vivo immunophenotype enriched for HSCs) were also of the 18−/− genotype 12 months after the competitive bone marrow transplant (Table 1). These data indicate that p18−/− hematopoietic cells including the primitive HSCs have a strong competitive advantage over wild type cells.
[0034] To test whether the enhanced engraftment was attributed to increased self-renewal of hematopoietic cells in the absence of p18, serial transplantation was integrated with the competitive bone marrow transplant assay. We collected bone marrow cells from mice 10 months after the primary competitive bone marrow transplant and performed a secondary competitive bone marrow transplant. Bone marrow nucleated cells from the primarily transplanted mice were rechallenged with an equal amount (2×10 6 ) of marrow nucleated cells newly isolated from p18+/+ animals at 8 weeks of age.
[0035] Strikingly, the p18−/− hematopoietic cells were still able to outcompete the co-transplanted p18+/+ cells and became dominant again in the new recipients 8-12 months following the secondary competitive bone marrow transplant. These results are shown in FIG. 2 .
[0036] FIG. 2 shows sustained multipotentiality and dominance of the regenerated p18−/− HSCs after secondary competitive bone marrow transplant. Bone marrow cells firm the mice at 10 months after primary competitive bone marrow transplant were mixed with freshly isolated bone marrow cells from non-transplanted wild type mice at age of 8 weeks at a 1:1 ratio and secondarily transplanted into lethally irradiated wild-type recipients (4×10 6 cells in total/mouse). Semi-quantitative PCR was again performed for blood cells drawn from the mice after secondary competitive bone marrow transplant. FIG. 2 a shows representative data for the blood cells collected at 8 months after secondary competitive bone marrow transplant. In FIG. 2 a , columns numbered 8 to 14 identify the seven individual mice used. The same standardization curve as shown in FIG. 1 a was used for this analysis since both batches of DNA samples were amplified at the same time under identical conditions. FIG. 2 b shows a lineage differentiation profile. Marrow cells from the mice (number 8, 9 and 10) 12 months after secondary competitive bone marrow transplant were stained with lineage markers for granulocytes (G), monocytes (M), T cells (T) or B cells (B) and each lineage was sorted for genotypic analysis with the semi-quantitative PCR method as described in FIG. 1 .
[0037] FIG. 2 a shows that the LTRA of the p18−/− hematopoietic cells assessed in the secondary recipients remained on average 8-fold greater than that of the p18+/+ cells. FIG. 2 b shows that the flow cytometric analysis of blood and bone marrow cells from the secondary recipient mice revealed no predominant growth of a specific lineage as compared to the non-transplanted wild type mice.
[0038] To further characterize the breadth of cell types repopulated by the p18−/− cells, immunophenotypically defined cell types from different lineages were sorted from the marrow at 12 months after the secondary competitive bone marrow transplant, and tested for the genotypic ratios. Similar to what was found with whole blood cells, the dominance of the p18−/− phenotype was observed in all major blood cell types ( FIG. 2 c ). These data indicate persistence of regenerated cells with multilineage differentiation potential (HSCs) in secondary recipients.
[0039] Stem cell concentration tends to decrease with serial bone marrow transplantation and we previously observed premature exhaustion of HSCs in the absence of p21. To test whether the p18−/− HSCs manifest the same outcome, we isolated one of the most primitive phenotypes for murine HSCs in vivo, the CD34 − LKS cells from the mice at 12 months after the secondary competitive bone marrow transplant and determined their genotypic characteristic at the single cell level. These results are shown in Table 1.
[0040] FIG. 17 shows sorting strategies for the stem cells with the immunophenotype, CD34 − LKS. To isolate the most primitive stem cells, we first exclude the mature cell populations, then enrich the cells with Sca-1/Ckit antibodies and finally gate them in the CD34 negative subset.
[0041] Table 1 shows that among 109 clones from 3 mice, 92.7% of the CD34 − LKS cells were of p18−/− origin. See Table 1, bottom line. Therefore, the p18−/− genotype sustains its predominant representation in the HSC pool through nearly two years of serial competitive bone marrow transplant without apparent exhaustion. These results were also confirmed by LTC-IC yield from an independent serial transplantation experiment (data not shown). The absence of p18 provides a capacity for increased self-renewal not seen in the absence of the CKI p21 or p27.
[0042] Growth advantage of p18−/− CD34 − LKS cells over their wild type counterparts in the competitive repopulation models suggests a possible expansion of HSCs in the p18−/− non-transplanted mice under homeostatic conditions. This possibility was examined with the phenotypic analysis between litter mate or age matched p18+/+ and p18−/− mice with the HSC phenotype, CD34 − LKS. Our results are shown in FIG. 3 .
[0043] FIG. 3 shows the enlarged pool size of HSCs in p18−/− mice under steady-state conditions and enhanced regeneration of p18−/− HSCs following the HSC transplantation.
[0044] FIG. 3 a shows phenotypic quantitation of HSCs. Bone marrow nucleated cells from p18−/− mice (8-12 weeks) and gender matched p18+/+ mice were analyzed by flow cytometry (n=9). HSCs that are negative for lineage markers and CD34, positive for c-Kit and Sca-1, are referred to as “CD34 − LKS” cells (see FIG. 17 ).
[0045] FIG. 3 b shows repopulating potential of HSCs with limiting dilutions. Different numbers (10, 20 or 40) of CD34 − LKS cells (CD45.2 + ) were mixed with 10 5 Sca-1 depleted competitor bone marrow cells (CD45.1 + /CD45.2 + ) and injected into lethally irradiated recipients (CD45.1) (n=10 mice per cell dose). Different lineages in the peripheral blood were analyzed 5 and 14 weeks after transplantation. A level of 2.5 % or higher of CD45.2 + cells associated with multilineage differentiation was defined as positive engraftment in a given animal. CRU values were calculated with the software L-Calc (StemCell Technologies). The graph shows the difference of CRU values at 5 weeks (5 W) and 14 weeks (14 W).
[0046] FIG. 3 c shows repopulating ability in the recipients transplanted with a higher dose of HSCs. Eighty CD34 − LKS cells were co-transplanted with 10 5 Sca-1 depleted competitor bone marrow cells into lethally irradiated recipients (n=5). The graph indicates the repopulating ability of the test cells as determined by the ratios of CD45.2 to CD45.1/CD45.2 cells in blood at week 5 (5 W) and 14 (14 W) after transplantation. FIG. 3 d shows multi-lineage differentiation Profile. Multi-lineage differentiation was examined by using 6-color flow cytometric analysis. “GM”, “T” and “B” indicate lineages for myeloid cell (Gr-1 + and Mac-1 + ), T cell (CD3 + ) and B cell (B220 + ) respectively.
[0047] FIG. 3 a shows that we observed a 2-fold increase in frequency and 3-fold increase in absolute yield per marrow harvest of the CD34 − LKS cells in the p18 −/− mouse. In contrast, the more mature Lin − c-kit + Sca-1 − (LKS − ) cells, which are devoid of HSC activity but contain committed HPC subsets, had an insignificant change in frequency. Therefore HSC, but not HPC populations appeared to be increased in the absence of p18.
[0048] A 2-fold increase of HSC frequency (CD34 − LKS) in p18−/− bone marrow was thought to be insufficient to account for the dramatic engrafting advantage of the p18−/− cells over the p18+/+ cells following the subsequent competitive bone marrow transplant ( FIG. 1 b and FIG. 2 a ). Rather, ongoing regeneration of 18−/− HSCs after transplantation was considered more likely. However, to further define this issue, we performed stem cell transplantation with CD34 − LKS cells to assay the competitive repopulation units (CRU) with limiting dilution analysis (10, 20 or 40 CD34 − LKS cells/mouse and 10 mice/dose). The original C57BL/6;129/Sv strain was backcrossed into the pure C57BL/6L-Ly5.2 (CD45.2) background for 10 generations allowing us to accomplish the experiment in congenic mouse strains (see FIG. 18 ).
[0049] We examined CRU frequency in CD34 − LKS cells at both week 5 and 14 after transplantation. Interestingly, while CRU frequency slightly increased from 1/22 to 1/14 in p18+/+ CD34 − LKS cells, it substantially increased from 1/12 to ¼ in p18 −/− CD34 − LKS cells ( FIG. 3 b ). Normalized for the frequency and yield of CD34 − LKS cells in the marrow, there was approximately a 7-fold increase in frequency and a 10-fold increase in absolute yield (2 femurs and 2 tibias) of CRU in the p18−/− bone marrow at 14 weeks post-transplant. The difference as assessed by CRU assay was in agreement with the data obtained from the mice injected with a higher dose of 80 CD34 − LKS cells per mouse ( FIG. 3 c ). There was also a 7-fold increase of relative engraftment level as compared to competitor cells in p18−/− groups at 3 months post-transplant without apparent alteration in lineage differentiation ratios ( FIG. 3 d ). These data concur with the 14-fold increase in p18−/− LTRA by the competitive bone marrow transplant model shown in FIG. 1 b , if normalized for the 2-fold increase of CD34 − LKS cells in the unfractioned marrow. See FIG. 3 a , left column.
[0050] Taking together the selective increase of CD34 − LKS cells that was not observed in the more mature LKS − cells ( FIG. 3 a ) and the apparent self-renewal of CRU seen in CD34 − LKS cells ( FIG. 3 b ), suggested a specific effect of p18 on HSCs. To directly address this issue, we measured cell divisions in distinct immunophenotypically defined cell populations among donor cells in irradiated recipients after bone marrow transplantation (BMT). The dye, 5- (and 6-) carboxy fluorescein diacetate succinimidyl ester (CFSE), was used to label the donor cells prior to tail injection and surface markers for HSCs and HPCs were applied to co-stain the marrow cells harvested 2 days after BMT. The number of initial cell divisions was measured based on the intensity of CFSE in each cell population in the recipients.
[0051] Within 3 cell divisions detected in the experiment, there was a significant increase of the cells that divided and retained the same phenotype in both p18−/− Lin − Sca-1 + and p18−/− Lin − Sca-1 − parent populations compared with the p18+/+ controls (measured as “precursor frequency” in flow cytometry). However, among the p18−/− cells, the increase of cell division seen in the more primitive Lin − Sca-1 + cell subset was markedly more (approximately 2-fold more) than that seen in the more mature Lin − Sca-1 − cell subset. Our data is shown in FIG. 4 .
[0052] FIG. 4 shows a direct demonstration of increased divisions of the p18−/− HSCs in vivo. Bone marrow cells were labeled with CFSE, injected into lethally irradiated recipient mice and harvested at 2 days after the transplantation for assessing the number of cell divisions. Cells were stained with the lineage and stem cell markers described in the methods. CFSE labeled cells were analyzed in the gate for a specific phenotype.
[0053] FIG. 4 a shows a representative figure of the flow cytometric analysis. The blue peaks on the right indicate undivided cells (parent cells) and each peak towards left side represents one cell division or generation. The percentages of the cells in each division obtained in a representative experiment are inserted in the graphs. The figure shown is from one of 4 experiments with similar results.
[0054] FIG. 4 b shows a summary of the mean values from 4 independent experiments. An assumption made in the computation model is that cell number will double as cells proliferate through each daughter generation in a given population (Lin + vs. Lin − Sca-1 − vs. Lin − Sca-1 + ). The ModFit LT software was used to calculate “precursor frequency” as the proportion of the total cells calculated to have been present at the start of the experiment (derived by back-calculation according to the model) which have then gone on to true proliferation during the course of cell division. Data shown are the ratios of the precursor frequency between p18−/− and p18+/+ cell populations (4 experiments, 3-5 donor mice/each genotype in each experiment).
[0055] Therefore, FIG. 4 shows that depletion of p18 does not result in a generalized increase in cell proliferation of different lineages. Rather, the absence of p18 preferentially affects divisions of the more primitive cells, resulting in improved HSC self-renewal.
[0056] FIG. 5 shows graphs measuring BrdU incorporation. To assess the cell cycling status in different hematopoietic subsets in vivo, either transplanted or non-transplanted mice were pulsed with a single dose of bromodeoxyuridine (BrdU) and mice were sacrificed in the second day for assessing the BrdU incorporation in conjunction with different hematopoietic markers. We found that there was no difference of BrdU incorporation in the hematopoietic cell subsets between p18−/− and p18+/+ groups. While we could not definitively document the difference at the true stem cell level in a most stringent term, our data suggest no overwhelming increase of cell proliferation in the stem cell progenies in the p18−/− marrow.
[0057] FIGS. 6, 7 and 8 show proliferative rates of the single stem or progenitor cell in vitro. To further assess the stem cell proliferation in at single cell level, we examined in vitro cell divisions of the CD34 − Lin − c-Kit + Sca-1 + (CD34LKS) or Lin − c-Kit + Sca-1 + (LKS) cells. Single CD34 − LKS or LKS cells were deposited to Terasaki plates (one cell/well) and cultured in serum free medium supplemented with SCF, Flt3L and TPO. While most cells entered cell cycle within 3 days, which was in agreement with previous studies by others, surprisingly, there was no significant difference in the rate of cell division between p18−/− and p18+/+ CD34 − LKS cells, neither in the LKS cells (>100 cells/cell type/experiment, 5 experiments in total). Further, there was also no difference in the rate of the first cell division of the CD34 − LKS cells. These indicate that p18 deficiency does not increase the proliferative rate of HSC, rather modulates the fate choice of HSC toward symmetric cell divisions. While one might still argue for the possibility of contamination of the progenitor cells in the immuophenotypes especially the LKS population, our data strongly demonstrate no substantial increase of proliferative rate in the progenitor cell pools.
[0058] FIG. 9 shows the selective expansion of CAFC during long-term culture. To demonstrate whether increased stem cell self-renewal may be readily achieved in vitro due to the absence of p18, we performed the Dexter long-term culture of bone marrow cells to enumerate the CAFC. There was no difference of CAFC yield in the first 4 weeks of the long-term culture between p18−/− and p18+/+ flasks. However, significantly more CAFCs were constantly generated in p18−/− than in p18+/+ flasks (n=4) from 6 weeks to 19 weeks after the initial culture. Strikingly, the frequency of CAFC at week 19 in p18−/− culture was still equivalent to its level at week 5, whereas the p18+/+ culture nearly lost its ability of producing CAFCs at week 19. In contrast, there wan no apparent difference of CFU at day 7 (an in vitro assay for hematopoietic progenitors) frequency between these two groups. It should be noted that CAFC has been extensively demonstrated by others to be correlated with the long-term repopulating stem cell activity in vivo in mouse models.
EXAMPLES
[0059] To compile the aforementioned data and confirm the operability of my concept, we have done the following experiments.
Example 1
Obtain p18+/+ and −/− Mice
[0060] p18+/− mice in a C57BL/6;129/Sv background were imported from the laboratory of David Franklin at Purdue University. p18−/− or +/+ mice were generated from p18+/− breeding pairs. Mouse colonies were maintained in the certified animal facility at University of Pittsburgh Cancer institute. Mice were genotyped by a PCR approach using the tail DNA (primers described below). Littermates or age-matched mice (8-12 weeks) were used in competitive bone marrow transplantation and stem cell phenotypic analysis.
[0061] For transplantation with purified stem cells and CRU analysis, the mice with the mixed background were bred back into C57BL/6-Ly5.2 (CD45.2) background for 10 generations. Wild type recipients in a C57BL/6129 background for BMT and mice with a B6.SJL-Ly5.1 (CD45.1) congenic background were purchased from the Jackson laboratory (Bar Harbor, Me.). All the procedures involved in the mouse work were approved by the Institutional Animal Care and Use Committee at the University of Pittsburgh.
Example 2
Competitive Bone Marrow Transplantation
[0062] Equal numbers of bone marrow nucleated cells (2×10 6 each) from p18+/+ and p18−/− mice were mixed and transplanted into the recipients which were treated with 10 Gy whole-body irradiation at the rate of 5.96 Gy/min or 0.94 Gy/min depending on the configuration of a specific 137 Cesium irradiator used in different experiments.
[0063] To perform the secondary competitive bone marrow transplant, bone marrow cells were harvested from the mice at 10 months after the primary competitive bone marrow transplant, mixed with freshly isolated wild type bone marrow cells (non-transplanted cells from mice at age of 8 weeks) at a 1:1 ratio and secondarily transplanted into new lethally irradiated wild-type recipients (age of 8 weeks). Blood from the transplanted mice was collected at different time points for genotypic analysis with the semi-quantitative PCR method. At varied time points after the primary or secondary competitive bone marrow transplant, some mice were sacrificed and bone marrow nucleated cells were used for genotypic analysis in different lineages and HSC or HPC compartments involving the single cell or colony assays.
[0064] The results of this is shown in FIG. 1 . FIG. 1 shows preferential outgrowth of p18−/− hematopoietic cells during long-term engraftment after primary competitive bone marrow transplant. Bone marrow cells from p18−/− and p18+/+ mice were mixed with a 1:1 ratio and injected into lethally irradiated recipient mice (4×10 6 cells in total per mouse). Semi-quantitative PCR was performed at different time points to determine the contribution of each genotype to the hematopoietic reconstitution after competitive bone marrow transplant. FIG. 1 a shows standardization based on the correlation between the relative density of p18−/− signal in total for each lane on the gel and the actual ratio of the two cell populations. FIG. 1 b shows representative data for blood cells at 7 months after competitive bone marrow transplant. FIG. 1 b , columns numbered 1 to 7 indicate the seven individual recipient mice used. According to the standardization, the converted percentages of p18−/− cells in the blood were shown below the PCR gel.
Example 3
Semi-Quantitative PCR and Single-Colony PCR
[0065] The contribution of p18+/+ or p18−/− cells was determined by semi-quantitative PCR with the following 3 primers:
p18WT-F (5′-AGCCATCAAATTTATTCATGTTGCAGG-3′) P18MG-47-R (5′-CCTCCATCAGGCTAATGACC-3′) PGKNEO-R (5′-CCAGCCTCTGAGCCCAGAAAGCGAAGG-3′)
The spleen cells from p18+/+ and p18−/− mice were mixed at different ratios for standardization of the PCR reaction. For single colony PCR, individual colonies were picked up with micromanipulation and lysed in 1×PCR buffer containing 2.5 mM MgCl 2 and 100 μg/ml Proteinase K for 1 hour at 60° C., followed by inactivation of the reaction for 20 min at 95° C.
Example 4
CFC and LTC-IC Cultures
[0066] Bone marrow cells were placed in the defined methycellulose medium M3434 (StemCell Technologies) and plated in 24-well plates. The CFC colonies were then scored at day 7-14 under an inverted microscope, picked up and assayed for the p18 genotype with PCR. Long-term culture with limiting dilution was performed as previously described. Briefly, the unfractioned bone marrow cells were plated on an irradiated (15Gy) primary mouse stromal monolayer in 96-well plates containing 150 μl of M5300 medium (Stem Cell Technologies) supplemented with 10 −6 M hydrocortisone. Sufficient wells at the limiting dose of approximately one long-term culture-initiating cell (LTC-IC) per well were included. The medium was changed with half fresh medium weekly and the long-term culture at week 5 was overlaid with 100 μl of M3434 (Stem Cell Technologies). The plates were evaluated for the presence of CFC colonies at 10 days. The colonies were microisolated and followed by PCR analysis for the p18 genotype.
Example 5
Flow Cytometric Analysis
[0067] For stem cell quantitation, the bone marrow nucleated cells were stained with a mixture of biotinylated antibodies against mouse CD3, CD4, CD8, B220, Gr-1, Mac-1 and TER-119 (Caltag), lien co-stained with streptavidin-PE-Cy7, anti-Sca-1-PE, anti-c-Kit-APC and anti-CD34-FITC (BD PharMingen). Propidium iodide was used for dead cell discrimination. A MoFlo High-Speed Cell Sorter (DakoCytomation) and the Summit software (version 3.1, DakoCytomation) were used for data acquisition and analysis. For lineage phenotype analysis, 50 μl of the blood was stained with either anti-CD3-PE and anti-B220-FITC or anti-MAC-1-PE and anti-Gr-1-FITC. The red cells were lysed with FACS Lysing Solution (BD Biosciences) and analyzed by the Beckman-Coulter XL cytometer.
Example 6
Single Stern Cell Sorting and Culture
[0068] The Sca-1+ cells were isolated from bone marrow cells using the EasySpe kit according to the manufacturer's protocol (StemCell Technologies) and then stained with a mixture of lineage-specific antibodies listed above, anti-c-kit-APC and anti-CD34-FITC. LKS or CD34 − LKS cells were sorted into 384-well plates (Nunc) at one cell per well using the MoFlo High-Speed Cell Sorter with subsystems of CyCLONE Automated Cloner and SortMaster Droplet Control. Each well contained 50 μl of IMDM supplemented with 50 ng/ml of Flt3 ligand (Flt3-L), 50 ng/ml of SCF and 10 ng/ml of TPO. After culture for 14 days, the morphology of each colony was examined under a microscope and the colonies were lysed for PCR.
Example 7
Stem Cell Transplantation with Limiting Dilution Analysis
[0069] Sorted CD34 − LKS cells from p18−/− mice in the background of C57BL/6 (CD45.2) were used for measuring the competitive repopulating unit (CRU). CD34 − LKS cells at a limiting dose (40, 20 or 10 cells/mouse) were mixed with 1×10 5 Sca-1-depleted bone marrow cells from F1 mice of C57BL/6 and B6.SJL (CD45.1 + and CD45.2 + ). The cell suspension was injected through tails into B6.SJL (CD45.1 + ) mice that were irradiated at a fractioned dose of 11Gy. Ten recipients were included for each group at each dose. Blood cells from the recipients were stained with PE-CD45.1 and FITC-CD45.2 to determine engraftment level of donor cells after transplantation. 2.5% or higher of CD45 + cells containing granulocytes, monocytes and lymphocytes was defined as positive engraftment in a given animal. The Beckman-Coulter XL cytometer was used for data acquisition. Based on the Poisson distribution of the negatively engrafted mice, CRU values were calculated with the software L-Calc (StemCell Technologies) and plotted in a graph. Animals that died during the course were not counted in the limiting dilution analysis. As an independent test to determine the engraftment levels, additional 5 recipient animals for each group were transplanted with a higher dose of CD34 − LKS cells (80 cells/mouse).
Example 8
In Vivo Assay for Tracking Cell Divisions
[0070] Bone marrow cells were labeled with one μM of CFSE (Molecular Probes) as described. 1×10 8 CFSE labeled p18+/+ or p18−/− bone marrow cells were injected into a lethally irradiated mouse. Two days after transplantation, recipient marrow cells were stained with the antibody cocktail for lineage markers, Sca-1 and c-Kit. MoFlo High-Speed Cell Sorter was used for data acquisition and the ModFit LT software (Version 3.0, Verity Software House) was used for cell proliferation analysis.
[0000] Statistical Analysis
[0071] The student's t test was used to analyze the statistical differences between p18−/− and p18+/+ groups with the p values indicated in the related graphs.
[0000] Summary
[0072] While both p21 and p18 appear to affect cycling kinetics in primitive cells, they have very distinct phenotypes: p21−/− stem cells undergo premature exhaustion, while p18−/− stem cells self-renew. Without overwhelmingly non-specific proliferation in other cell populations, increased regeneration of p18−/− HSCs suggests that the balance of differentiation to self-renewal in the absence of p18 favors self-renewal. This notion is indirectly supported by the data from others demonstrating that p18 expressing cells have an increase in asymmetric division. It is believed that critical decisions of cell fate are made during the G1-phase. Upon mitogenic stimuli, cyclin D is upregulated and interacts with CDK4/6, resulting in Rb phosphorylation to initiate cell cycle progression. White Cip/Kip proteins (such as p21) broadly inhibit CDK2 in late G1/S and possibly CDK1 in M phase, they are not capable of inhibiting CDK4/6 activity early in G1. In contrast, INK4 proteins (such as p18) are able to specifically compete with cyclin D to bind CDK4/6 in early G1. Given the distinct effects of these two CKI families in stem cell regulation, we propose a model in which modulation of a distinct CKI or its class at a specific position of the cell cycle may be an important mechanism for balancing self-renewal and differentiation in stem cells. Down modulating p18 may permit enhanced stem cell expansion, a hypothesis that can now be tested in adult cells.
[0073] While I have discussed various specific examples in some detail above, one of skill in the art could, with the teachings here, readily develop alternative solutions. Thus, I intend the coverage of my patent to be defined not by the specific abstract nor examples discussed here, but rather by the appended claims and their legal equivalents.
[0074] In the claims, I use certain terms in specific ways. For example, the singular allows for more than one (e.g., the claim phrase, “a compound selected from the group consisting of A, B and C” covers a composition with at least one—and perhaps two or more—of the enumerated compounds).
[0075] I use the claim term “symmetrically self-renewing population” to encompass both in vitro cell culture and in vivo culture as, for example, a therapeutic or experimental implant.
[0076] I use the claim term “human-compatible” to mean able to be survivably-implanted in a human. This may be done by, for example, using a non-immunogenic cell line which will provoke little or no immune response, or by the conjoint administration to the human patient of an immunosuppressant pharmaceutical to suppress the immune response to the stem cell implant. A non-immunogenetic cell line may be, for example, the patient's own stem cells, extracted from the patient and cultured ex vivo for autologous delivery back to the patient.
[0077] I use the term “intracellular environment” to mean the intracellular environment of the stem cell culture. I use the term “substantially free” to mean an amount less than the amount which would materially inhibit cell line regeneration. One may control the intracellular environment by, for example, limiting expression of the p18 protein; this may be done by deleting or mutating the p18 gene (to make a p18−/− genotype cell) or its promoter (to make a p18− phenotype cell), or by downregulating the gene promoter, or by providing a compound capable of binding and thus neutralizing the p18 protein. One known approach to down-regulating gene expression is inhibiting expression of p18 by using “RNA interference,” that is, using small interfering RNA or RNA-directed gene silencing. I do not imply any unstated temporal limitation on this; thus, for example, I intend my claims to cover transient downregulation of p18 transcription, or transient binding or enzymatic lysis of the p18 protein, such that the cells may revert to a p18+ phenotype once the p18-inhibiting factor is removed.
[0078] In the claims, I use the term “p18” to mean the polypeptide as known in the art (see supra), but also any mutation of it which differs from it insubstantially. Thus, for example, a wild-type variant or mutant which, despite its nominal difference from the published sequence for p18, achieves a similar function of impeding a cell line's regenerative capacity, is considered “p18” for the claims appended.
[0079] A Change of p18 expression level or a block of p18 function in cell lines can be used to screen potential drug candidates for stem cell renewal, to assay the effectiveness of potential drug candidates on p18+ and p18− cells. Thus, in the claims, I use the term “candidate composition” to mean a composition of matter which is a candidate for some kind of therapeutic use; it can be a small organic chemical, for example, or a polypeptide. | A method to increase self-renewal of an undifferentiaded human stem cell culture or cell line, by reducing or eliminating the presence of the protein “p18”. | 2 |
TECHNICAL FIELD
[0001] The disclosure relates to a jet engine nacelle for an aircraft.
BACKGROUND
[0002] An aircraft is propelled by a number of jet engines each housed in a nacelle which also accommodates a collection of auxiliary actuating devices associated with the operation thereof and performing various functions when the jet engine is operating or stationary. These auxiliary actuating devices particularly comprise a mechanical system for actuating thrust reversers.
[0003] A nacelle generally has a tubular structure comprising an air inlet in front of the jet engine, a mid-section intended to surround a fan of the jet engine, and a rear section accommodating thrust reversal means and intended to surround the combustion chamber of the jet engine, and is generally terminated by an exhaust nozzle whose outlet is situated downstream of the jet engine.
[0004] Modern nacelles are often intended to accommodate a turbofan jet engine designed, via the blades of the rotating fan, to generate a hot air stream (also known as primary stream) from the jet engine combustion chamber.
[0005] A nacelle generally has an outer structure, termed Outer Fixed Structure (OFS), which, together with a concentric inner structure, termed Inner Fixed Structure (IFS), comprising an inner panel surrounding the actual structure of the jet engine to the rear of the fan, defines an annular flow duct, also termed flow path, aimed at channeling a cold air stream termed secondary steam, which flows around outside the jet engine. The primary and secondary streams are ejected from the jet engine via the rear of the nacelle.
[0006] Certain equipment of the jet engine conduct highly pressurized fluids. In the event of untimely breakage of this equipment, the inner panel is subjected to a high excess pressure which can lead as far as the destruction of a part of said panel and/or of the equipment housed in this environment. To avoid this destruction, it is commonly accepted to install one or more excess pressure flaps in the rear part of the inner panel of the outer structure, at the outlet of the annular duct, the gas flow rate constituting the excess pressure then being theoretically discharged directly to the outside of the nacelle.
[0007] Nevertheless, the gas flow rate generated by the explosion produced in the jet engine compartment can be expelled only after having travelled the whole way to the nearest excess pressure flap. Now, it has been found in practice that this distance had the effect of greatly limiting the benefit of integrating such excess pressure flaps, insofar as the structure and/or the equipment could suffer before the excess pressure is discharged. In certain cases, it has even been found that these excess pressure flaps did not play any role.
[0008] It is known from document U.S. Pat. No. 4,825,644 to form exhaust means in the inner panel, these exhaust means comprising at least one excess pressure flap equipped with spacing means for ensuring a minimum discharge flow rate to the outside in the event of untimely excess pressure, said spacing means being produced with the aid of at least one strut equipped with locking means designed to lock said strut in its spacing position in the event of excess pressure requiring the opening of the excess pressure flap. Consequently, the untimely excess pressure occurring in the jet engine compartment is immediately discharged inside the annular duct via the exhaust means, and cannot therefore cause the destruction of the inner panel and/or the surrounding equipment.
BRIEF SUMMARY
[0009] The disclosure aims at providing an alternative solution and to that end comprises a nacelle for a jet engine, of the type comprising a rear section made up of an outer structure which, together with a concentric inner structure comprising an inner panel intended to surround a downstream portion of the jet engine, defines an annular flow duct for a so-called secondary stream, said nacelle comprising exhaust means formed in the inner panel and comprising at least one excess pressure flap equipped with spacing means for guaranteeing a minimum discharge flow rate to the outside in the event of an untimely excess pressure, said spacing means being produced with the aid of at least one strut equipped with locking means designed to lock said strut in its spacing position in the event of excess pressure requiring the opening of the excess pressure flap, characterized in that the strut comprises a hollow casing in which a rod can slide, said casing having an end fixed in the excess pressure flap and said rod having an end fixed in the inner panel, and in that the locking means are produced with the aid, on the one hand, of a locking finger housed in the casing and having a first end mounted pivotably about an axis in the region of the end of the casing fixed in the excess pressure flap and a second end housed in a cavity formed in the rod, and, on the other hand, elastic return means designed so as to longitudinally off-center said locking finger with respect to the cavity of the rod when said rod has slid in the casing, thus preventing its rearward return.
[0010] Advantageously, the exhaust means are positioned at the front of the inner panel.
[0011] It should go without saying that another solution for overcoming the potential risk of reclosure can also exist in the integration of means for braking the reclosure movement of the excess pressure flap, such that the latter can find its point of equilibrium.
[0012] Thus, in a nacelle according to this disclsoure, the location of the excess pressure flap or flaps can be chosen to be as close as possible to the equipment of the jet engine which is likely to create the highest excess pressure, such that this or these excess pressure flap or flaps are capable of discharging this excess pressure without stressing the stiffness of the inner panel of the inner structure.
[0013] Specifically, to the disclosure seeks benefit from the very high local excess pressure in the vicinity of the point of the explosion in order to promote the immediate opening of the exhaust means, thereby finally allowing a quasi-instantaneous expulsion of the gases generated by the explosion. The risk of damaging the inner panel and/or the surrounding equipment is therefore considerably reduced.
[0014] The immediate advantages of such an installation are a weight and cost saving since, given that the inner panel of the inner structure is no longer stressed by any untimely excess pressure, there is no longer any need to dimension it so that it can withstand such stresses. Furthermore, aircraft manufacturers have more freedom as to the choice of the location of the excess pressure flap or flaps along the annular duct.
[0015] Given the position of these exhaust means, a nacelle according to an exemplary embodiment comprises detection means designed so as to make the actuation of the exhaust means visible from the outside.
[0016] Advantageously, the detection means comprise a control system whose activation is conditioned by the activation of the exhaust means.
[0017] More advantageously still, the control system is connected to at least one external mechanical display member via transmission means.
[0018] In an exemplary embodiment, the control system comprises a prestress trigger, connected to the transmission means, the release of which is conditioned by the actuation of the exhaust means.
[0019] The disclosure also relates to an aircraft comprising at least one nacelle according to an exemplary embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Implementation will be better understood from the detailed description which is explained below with reference to the appended drawing, in which:
[0021] FIG. 1 is a schematic view in longitudinal section of a nacelle according to an exemplary embodiment in the closed state;
[0022] FIGS. 2 and 3 are partial perspective schematic views of the inner panel of a nacelle according to an exemplary embodiment when the excess pressure flap is deployed;
[0023] FIG. 4 is a perspective view of the excess pressure flapin an exemplary embodiment;
[0024] FIG. 5 is a partial view in longitudinal section of the strut, when at rest, of the excess pressure flap represented in FIG. 4 ;
[0025] FIG. 6 is a partial view in longitudinal section of the strut, when deployed, of the excess pressure flap represented in FIG. 4 ;
[0026] FIG. 7 is a partial schematic view of the nacelle represented in FIG. 2 , equipped with detection means.
DETAILED DESCRIPTION
[0027] A nacelle of an aircraft 1 according to an exemplary embodiment as represented in FIG. 1 , comprises in a manner known per se an outer structure 2 , termed OFS, which defines an annular flow duct 3 with a concentric inner structure 4 , termed IFS, surrounding the structure of the jet engine (not shown) to the rear of a fan ( 5 ).
[0028] More precisely, this outer structure 2 is broken down into a front air inlet section 6 , a mid-section 7 intended to surround the fan 5 , and a rear section 8 generally formed by at least two half-shells.
[0029] The inner structure 4 comprises an inner panel 10 which surrounds a downstream portion of the jet engine. As represented in FIGS. 2 and 3 , exhaust means 11 are provided in this inner panel 10 so that any untimely excess pressure occurring in the jet engine compartment is discharged into the annular duct 3 .
[0030] These exhaust means 11 are preferably positioned at the front of the inner panel 10 so as to be situated as close as possible to the sensitive regions in which excess pressure may occur due to an explosion in the jet engine compartment. These exhaust means 11 comprise at least one excess pressure flap 12 equipped with a strut 13 . The excess pressure flap 12 is attached to the inner panel 10 , and is pivotably mounted about the latter via a set of hinges 9 .
[0031] A nacelle according to an exemplary embodiment is represented more specifically in FIGS. 4 to 6 .
[0032] The strut 13 of the excess pressure flap 12 comprises a cylindrical hollow casing 14 in which a rod 15 can slide. This casing 14 has an end 16 pivotably mounted about an axis 33 in a fastening plate 31 attached to the excess pressure flap 12 , and the rod 15 , extending the casing 14 , has an end 17 pivotably mounted in a fastening block 32 attached to the inner panel 10 of the inner structure 4 .
[0033] More precisely, and as represented in FIGS. 5 and 6 , a locking finger 120 is housed in the casing 14 , and is arranged between the end 16 thereof and the rod 15 .
[0034] More precisely, this locking finger 120 has a first end 121 pivotably mounted about the axis 33 in the region of the end 16 of the casing 14 , and a second end 123 housed in a cavity 124 formed in the rod 15 .
[0035] Furthermore, elastic return means are produced in the form of at least one compression spring 122 . The latter is arranged transversely to the locking finger 120 in the region of the end 16 of the casing 14 , and has a first end 125 bearing against the inner face of the lateral surface 30 of the casing 14 , and a second end 126 housed in a transverse blind bore 127 formed in the locking finger 120 .
[0036] In this way, when the excess pressure flap 12 is in the closed position in the continuation of the inner panel 10 of the inner structure 4 , the casing 14 , the locking finger 120 and the rod 15 are coaxial to one another.
[0037] On the other hand, in the event of untimely excess pressure in the jet engine compartment which is sufficient to cause the excess pressure flap 12 to open, the rod 15 is caused to slide in the casing 14 as represented in FIG. 11 , and the second end 123 of the locking finger 120 is extracted from the cavity 124 of the rod 15 owing to the sliding of the latter into the deployed position. The compression spring 122 can then force the first end 121 of the locking finger 120 to pivot about said axis 33 , the effect of which is to longitudinally off-center the locking finger 120 with respect to the cavity 124 of the rod 15 . Said rod will therefore be locked in the case of rearward return since the second end 123 of the locking finger 120 will no longer be positioned opposite the cavity 124 presented by the rod 15 .
[0038] Therefore, these locking means make it possible to lock the strut 13 in its spacing position which has been designed so as to ensure a minimum discharge flow rate to the outside in the event of untimely excess pressure.
[0039] It should be noted that the lateral surface 30 of the casing 14 may have an opening 128 which, during maintenance operations on the ground, makes it possible to reach the locking finger 120 and to force it to pivot about its axis 33 in order to arrange it parallel to the casing 14 and to the rod 15 , thereby finally allowing a rearward return of the latter.
[0040] Moreover, detection means 129 are advantageously provided to allow the operator or operators to check instantaneously from the outside whether the exhaust means 11 have been actuated or not in flight.
[0041] For that purpose, these detection means 129 comprise a control system whose activation is conditioned by the activation of the exhaust means 11 as represented schematically in FIG. 7 .
[0042] This control system will advantageously comprise a cam whose pivoting will be controlled by the opening of the excess pressure flap 12 . This cam will preferably be connected to a prestressed trigger which is connected to transmission means 130 attached to at least one external mechanical display member 131 .
[0043] More precisely, the pivoting of the cam will cause the release of the prestress trigger, which as it is released will exert a pull on the transmission means advantageously produced in the form of a cable 130 , this pull causing the deployment of the mechanical member preferably produced in the form of a “pop-out” -type device 131 as represented in the deployed position in FIG. 2 .
[0044] Although the disclosure has been described in connection with specific exemplary embodiments, it goes without saying that it is in no way limited thereto and that it comprises all the technical equivalents of the means described as well as the combinations thereof if they come within the scope of the disclsoure. | The present invention relates to a jet engine nacelle ( 1 ), of the type comprising an aft section forming an external structure ( 2 ) which, together with a concentric internal structure ( 4 ) comprising an internal panel ( 10 ) intended to surround a down-stream portion of the jet engine, defines an annular flow duct for a so-called secondary stream ( 3 ), characterized in that exhaust means ( 11 ) are formed in the internal panel such that any unwanted excess pressure is discharged into the annular duct. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a streamlined buoyancy package for subsurface instrumented moorings.
2. Description of the Prior Art
Conventional instrumented moorings for oceanographic studies, such as current measurement, include a line held taut by a main float with instruments for making measurements distributed along the line. Since the instruments and mooring line are normally heavier than water, additional buoyancy is required to maintain the line tension and also to minimize instrument excursions and inclinations in higher currents. Spherical buoyancy elements are typically used to provide this in-line buoyancy. In water depths of less than 200 m, hollow plastic balls are used to provide buoyancy, while in deeper water, hollow glass balls enclosed for protection are widely used. In both of these cases the buoyancy is not streamlined.
The present moorings are subjected to considerable drag and vortex shedding motion due to water currents. The buoyancy components are the main source of this type of motion. Drag on the buoyancy components results in horizontal displacement in ocean currents and consequently produces inclinations of the line and vertical displacements of the instruments attached to it.
Spheres used as in-line buoyancy set up mooring vibration which occurs at the Strouhal frequency (f=0.2×velocity/Diameter). Measurements have shown that the amplitude of motion can be as large as 0.5 meters, or 1 meter peak to peak. This motion is perpendicular to the water current. It has been found that the motion causes fluctuations in the measured relative water velocity which degrades current meter measurements.
Attempting to reduce unwanted motion by streamlining the buoyancy components presents a number of obstacles. With non-spherical buoyancy components proper orientation of the components (parallel with the current flow) must be maintained to achieve improved results.
At increasing depths, the design of non-spherical buoyancy components becomes increasingly difficult due to the increased pressures.
SUMMARY OF THE INVENTION
An object of the present invention to provide a streamlined buoyancy package for subsurface moorings to reduce instrument excursions and inclinations in water currents.
Another object of the present invention is to provide a streamlined buoyancy package for subsurface moorings with improved stability in water currents while being capable of withstanding external pressures.
It has been found that buoyancy for subsurface moorings with reduced drag and increased stability can be provided with the use of spherical buoyant members enclosed in a pivoting streamlined housing. The use of a spherical buoyant member provides a buoyant member capable of withstanding high pressures for deep water applications, and in one embodiment provides a convenient means for providing a pivot with respect to the housing.
The present invention provides a buoyancy package for subsurface moorings comprising a plurality of spherical buoyant members; a streamlined housing for enclosing the buoyant members, said housing having openings to allow pressure equalization with the surrounding water; and pivotal connection means for pivotally connecting the housing with a mooring line.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a system incorporating the streamlined buoyancy packages of the present invention.
FIG. 2 shows details of one embodiment of a streamlined buoyancy package in accordance with the present invention.
FIG. 3 illustrates a second embodiment of a streamlined buoyancy package in accordance with the present invention.
FIG. 4 is a fragmented sectional view taken at 4--4 of FIG. 3 showing details of the pivotal connection between the line tie rod and the housing of the buoyancy package.
FIG. 5 is a fragmented sectional view taken at 5--5 of FIG. 3 showing details of the pivotal connection between the line tie rod and the housing of the buoyancy package.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a typical subsurface mooring arrangement which comprises a line 1 held taut by an upper buoyancy package 2a beneath the sea surface 3 and positioned on the sea floor 4 by a suitable anchor 5. Attached to the line 1 are one or more additional buoyancy packages 2 to provide in-line buoyancy.
FIG. 1 also illustrates the vertical displacement y and the inclination angle a of the line, due to ocean currents 9.
With reference to FIG. 2, which illustrates one embodiment of present invention, each buoyancy package 2 comprises a plurality (three shown) of spherical buoyant members 21 surrounded by a streamlined housing 22. The assembly is attached to the line by means of the tie rod 23.
The housing has suitable openings 24 to allow pressure equalization with the surrounding water to avoid stress on the housing at depths.
The buoyant members 21 are retained in position by suitable bulkhead structure 26.
In the embodiment of FIG. 2, one of the buoyant members 20 is connected to the line by means of tie rod 23. The buoyant member 20 is free to rotate within the housing forming a pivotal connection or swivel to allowing rotation about a vertical axis which is coaxial with a longitudinal axis of the line. The arrangement also allows limited pivoting about a horizontal axis perpendicular to the longitudinal axis of the housing. This is made possible by the elongated opening 24 in the housing 22 which allows longitudinal motion of the end of the tie rod 23. Such pivoting of the housing about a horizontal axis allows the buoyancy member to remain horizontal when the line is inclined from the vertical due to water currents 9, as shown in FIG. 1. Remaining horizontal minimizes the frontal area and hence drag and thereby minimizes inclination that results due to drag.
It will be noted that the buoyant members 21 are arranged horizontally along an axis corresponding with a longitudinal axis of the housing. This arrangement allows a reduced frontal area and hence reduced drag as compared with a single buoyant member of the same volume.
The streamlined housing is connected to the line ahead of the hydrodynamic center to provide that it aligns itself to the flow. A stabilizer 25 facilitates alignment. Ribs 27 improve stability and structural rigidity of the housing.
The embodiment of FIG. 2 is suited for moderate depths and pressures since one of the buoyant members 20 is provided with a through hole that is penetrated by the tie rod 23.
FIGS. 3 to 5 illustrate another embodiment of the invention suited for greater depths and pressures. With reference to FIG. 3, the buoyancy package comprises a pair of buoyant members 31, for example glass spheres, surrounded by streamlined housing 32, and separate pivotal connection means 30. As in the embodiment of FIG. 2, the pivotal connection means 30 provides pivoting about both the horizontal and vertical axis.
Details of the pivotal connection means for the embodiment of FIG. 3 are shown in FIGS. 4 and 5.
With reference to FIG. 4 and 5, attached to the tie rod 33 are bearing or follower elements 47 adapted to cooperate with guiding elements attached to, or forming part of the housing 32. The guiding elements include a bearing surface 49 having a curved profile with radius corresponding to that of the follower element 47, and a longitudinal slot 48 (See FIG. 5) at the top and bottom of the housing for confining the lateral motion of the tie rod 33.
As best seen in FIG. 4, the follower 47 and bearing surface 49 cooperate to allow limited pivoting of the tie rod with respect to the housing and thereby allow the housing to remain horizontal when the line is inclined due to ocean currents, as shown in FIG. 1.
The tie rod 33 is free 19 rotate within the slot 45 to allow rotation of the package with respect to the line, to allow the buoyancy package to freely orient itself into the current to minimize drag, and also prevents twisting or "winding-up" of the buoyancy package and line.
Measured instrument displacements on a mooring using the streamlined packages of the present invention were typically 3 to 5 times less than with conventional in-line spherical buoyancy (Viny floats). The reduced motion provided by the present buoyancy package was found to overcome an under-reading problem previously encountered in current meter measurements.
It will be appreciated that various aspects of the buoyancy package may be varied from that shown, such as the number, materials, construction and retention of the buoyancy members, the construction of the housing, and the pivotal connection means. Also, measuring instruments may be placed inside the streamlined housing with the buoyancy members. | A buoyancy package for subsurface instrumented moorings with reduced drag and increased stability is provided with the use of spherical buoyant members enclosed in a pivotally connected streamlined housing. The use of a spherical buoyant member provides a buoyant member capable of withstanding high pressures for deep water applications, and in one embodiment provides a convenient structure for providing a pivot with respect to the housing. | 1 |
FIELD OF THE INVENTION
This invention relates to a melt blowing die apparatus for spinning filaments of molten synthetic fiber material to produce fibrous non-woven thermal insulating mats constructed of thermoplastic fibers and particularly, though not exclusively, to form high loft batts of linear condensation polymers, preferably polyester, for example, polyethylene terephthalate (PET). The mats may be thermally insulating mats in the form of mats, boards or batts with an insulating R value of at least 3.5/inch and preferably at least 4/inch. Specifically, the invention relates to control of the drawn filament by a flow of pressurized air flow parallel to the extruded filaments to provide attenuation of the filaments within an attenuation slot provided in a lower portion of the apparatus.
BACKGROUND OF THE INVENTION
It has been proposed to produce polyester (e.g. PET) non-woven insulating mats, constructed by melt-blowing techniques, having R values of 4.0 or more per inch with mats using substantially continuous fibers of 3-12 microns. However, mass production of high-loft batts suitable for the insulation of building structures have not, in the past, proved economical in spite of extensive research efforts devoted to producing such environmentally friendly products.
PET non-woven fiber mats, specifically for insulating purposes, whether commercial or domestic, have been proposed using melt blowing die equipment in which melted PET is extruded through a plurality of nozzles to form substantially continuous fibers which are then carried by a high velocity gas toward a fiber mat forming location, at which the fibers are laid down with self entanglement, resulting from the highly turbulent accelerating gas flow, to produce the desired batt integrity. It is proposed in the art to produce such insulating batts (and boards) via one or more arrays of nozzles disposed in a straight line arranged over the mat forming location to progressively produce the desired batt configuration as it is conveyed under the array(s). As the fibers are extruded by the nozzles, they are collected on a collection device, in a layer of fibers to form the insulating mats, batts or boards.
U.S. Pat. No. 5,248,247 discloses an aligned nozzle configuration, two slot ducts producing air jets directed to intersect, at an acute angle, the spin line below the nozzle carrying die face (or near it). The role of the air jets is to cause the extruded polymer filaments to be stretched and expose the fibers to turbulent air flow and preferably broken up prior to deposition in a random mass on the moving belt below the die. The main thrust of the patent is directed at the provision of a uniform driving pressure along the entire lateral die length for the air supply system feeding the slot nozzles. It is postulated, in this prior art, that even small variations, along the die length, in this total driving pressure applied to the slot air flow will lead to an unacceptable non-woven product/mat.
Other components of the meltblowing die are elongate plates referred to as air knives (nozzle bars), which form an accelerating air flow channel to, in combination with the die tip nose piece, form converging air flows to attenuate and draw down the extruded fibers to microsized diameters. The air knives are generally elongate plates which have a longitudinal edge tapered to form a knife edge. Two air knives are typically used and are fastened to the face of the die body on opposite sides of the triangular die tip nose piece. The tapered edges of the air knives are aligned with the confronting tapered surfaces of the nose piece and spaced slightly therefrom to form two flow channels which converge at the apex of the nose piece.
The spatial relationship between the air knives and the die tip is defined in the art by parameters known as air-gap and set-back. The air-gap and set-back determine the geometry of the converging air flow passages, and thereby control the airflow properties and the degree of fiber-air interaction.
The prior art melt blowing apparatus as disclosed in U.S. Pat. No. 5,248,247 for production of melt blown filament line is shown generally in FIG. 1 as comprising an extruder 1 , melt blowing die 4 and a collector drum or conveyor belt 12 . The extruder 1 delivers molten resin through an aligned evenly spaced series of nozzles 6 in the die 4 , where, upon exiting the nozzles 6 , an aligned evenly spaced plurality of filaments (fibers) 2 are extruded to be attenuated and passed down through tapered slits, in a lower portion of the apparatus onto the conveyor belt 12 , by pressurized, converging hot air streams. The tapered slit 11 is formed by adjacent parallel relatively thin nozzle bars 5 through which the combined air/fiber stream passes. The filaments 2 are then collected on the belt 12 to form a mat or fleece of insulation F.
The melt blowing apparatus also includes a source of pressurized air 3 communicating with the die 4 through valved lines 8 and heating elements 7 in order to produce the converging hot air streams 9 . Additionally, baffles and air pressure regulating devices 10 are provided together with the heating elements 7 and valved lines 8 to control the conditioned hot air streams 9 .
As is known to those in the art, the extruder 1 includes an interior cavity where PET chips or similar polymer material are pressurized, heated and melted to produce the molten PET resin. The extruder 1 is provided with the aligned evenly spaced plurality of nozzles 6 communicating with the cavity. The nozzles 6 are supplied with molten PET under pressure to form an aligned evenly spaced plurality of filaments 2 at a desired flow rate.
In conjunction with the molten resin flow, the hot air streams 9 are provided from the pressurized air source 3 via the valved lines 8 into confluence with the filament line 2 substantially adjacent the nozzle 6 . The hot air streams 9 are directed by an outlet oriented so as to introduce each of the air streams into the slit 11 at an acute angle to the direction of the flow of the filaments 2 , thereby attenuating and drawing the filaments 2 downwards towards the conveyor belt 12 as illustrated in FIG. 1 .
The slit 11 does not provide parallel flow controlling walls and is formed by the relative thin nozzle bars in which the slot forming walls converge throughout the vertical height of the slot and thereby fail to provide a controlled flow of the air, passing therethrough, parallel to the filaments and thus do not provide adequate control of filament attenuation and temperature. Here no mention of controlling the temperature of the slot walls is made.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide an improved melt blowing apparatus and method to more effectively control the properties of attenuated filaments formed thereby.
The main objective of the invention is to provide an attenuating air flow in a vertical direction, parallel to the exiting filament direction so that appropriate shearing forces may be applied to the extruded filaments in the attenuating channel. This objective is achieved by means of a small radius Coanda bend or by a suitably designed channel flow, immediately upstream from the entrance to the attenuating channel.
Another object of the invention is to provide adequate fiber entanglement below the die face and the exit plane of the slot discharge, by means of the highly turbulent flow field and the free air entrainment existing in this region.
SUMMARY OF THE INVENTION
Shearing forces applied to an extruding filament of molten synthetic fiber material (polymer) by a suitably configured air/gas flow system provide an important means of influencing and controlling the molecular orientation, crystallinity and crystal orientation in certain high speed fiber spin line applications. The control of both the magnitude and location of the applied shearing forces, through the design characteristics of the air/gas system, is crucial to the achievement of improved and optimized mechanical properties of the resulting drawn fibers.
In contrast to the above described prior art, the present invention provides an accelerating high velocity fiber attenuating air flow in a vertical, attenuating slot extending along the fiber length as it is extruded. At the entrance section of this slot, along the fiber center line, the extruded filaments move vertically downward with a relatively low velocity. In this slot surrounding these filaments is provided an accelerating parallel high velocity air flow, with a maximum velocity approximately two orders of magnitude greater than the emerging filament velocity. The air flow is supplied by two identical, mirror image, ducting systems symmetrically disposed one on either side of the die nozzle center line, with each incorporating a rapid turning section immediately upstream of the slot entrance, so that the air flow enters the attenuating channel flows in a substantially vertical (downward) direction. In the attenuating slot, shearing and attenuating forces and temperature quenching are applied to the extruded molten filaments. The final product's physical properties are critically dependent on the magnitude and time/space histories of the shearing and temperature quenching applied.
At the exit of the attenuating slot, the air discharge from the attenuating slot emerges as a free turbulent jet quickly acquiring high turbulent energy levels. In particular, large lateral turbulent velocity components are developed due to free air entrainment. The latter contribute significantly to the entanglement of the now rapidly solidifying or solidified filaments collected below the slot exit plane.
An important element of the present invention relates to the supply of suitably conditioned attenuating air flow to the extruded (polymer) filaments. To develop the necessary shear forces at the air flow/polymer interface, the air flow must be delivered to the spun filaments (fibers) in a substantially vertical direction (i.e. parallel to the length of the filaments), at a point as close to the exit of the extruded filament from the nozzles as possible. The air flow must execute a very tight turn, approaching 90°, to arrive at the vertical direction at or near the top of the spin line, after traversing an approximately horizontal path across the die extruding components (die nozzles) by which the filaments are extruded. A Coanda bend in the air supply is a preferred means of achieving this separation free flow turning.
Two identical air flow channels symmetrically converge on the die center line at the top of the spin line, on either side of the extruded filaments. The converged air flows from the systems, together with the extruded filaments, enter an attenuating slot, where the main shearing forces and temperature quenching are applied to the molten filaments. The degree of temperature quenching is controlled by the temperature difference maintained between the extruded fluid filament, at the die exit, and the conditioned attenuating air supply used.
Two alternative attenuating air supply systems are described to meet the major design objectives/requirements of the present invention. These objectives are:
The mean air flow velocity must be increased significantly to a high subsonic value at the downstream delivery location at the top of the spin line. The outlet/inlet velocity ratio required in the air system is on the order of 10:1 to 20:1 with the exact value dependent upon the required filament shearing forces and the drawing/attenuation needed in the final product.
The air flow must be turned to a substantially vertical discharge direction, by means of a small radius of curvature turn, at or immediately above the flow discharge into the attenuating slot.
The rapid turning and acceleration of the mean air flow in the system must be achieved without the introduction of any adverse flow pressure gradients on the walls defining the flow passages in the air supply system.
The delivered high velocity air flow at the top of the spin line must be uniform, along the length of the die, and uniformly across the inlet to the attenuating slot.
In the first of the general design approaches, FIG. 2 reveals a suitably configured and curved, fully attached internal flow channel to deliver the necessary air to the spin line. The air flow channel has a general “S” shaped center line contour, with the first, low speed turn directing the air flow entering (approximately vertical) across the bottom of the high pressure polymer nozzle assembly towards the spin line. The second, high speed turning in the “S” channel orients the discharge flow into the vertical spin line direction with a small radius bend. The air flow acceleration in the channel is such that high accelerations are applied in the low-velocity sections of the channel, including the first, low speed, turn, while small and vanishing accelerations are applied in the high-velocity sections including the second, high speed, turn. The final high speed turn must be carried out using a relatively small radius bend in order to permit the application of air shearing forces vertically at or near the top of the spin line. The entering air in the supply system is at a low velocity determined by the supply ducting and the blower/fan/compressor used to produce the necessary supply of air pressure and volumetric capacity of the die system. The air supply system also includes a suitable air heating unit to provide appropriate control of the temperature in the drawing/attenuating processes in and below the attenuating slot section. The final air discharge velocity from the supply system will typically be in the Mach No. range between 0.50 and 0.75 (400-800 f.p.s.) although wider limits are not precluded.
In the second of the general design approaches, for the air supply system (FIG. 4) the second turn described above which turns the air flow to the vertical spin line direction, is replaced by a short, approximately horizontal, wall jet section and a two-dimensional Coanda bend of approximately 90°. The curved free surfaces of the wall jet and the Coanda bend are vented to atmospheric pressure, as shown, through a suitable ducting arrangement. These free Coanda surfaces located symmetrically on both sides of the spin line entrain a significant volume of vented air prior to the convergence of the wall jets at the top of the spin line, at the entrance to the final attenuating channel section. On either side of the spin line trapped and standing vortices may be maintained above the curved free jet surfaces. Recirculation into the flow volume containing the trapped vortices must be terminated by a suitable wall contour design, prior to the convergence of the two Coanda wall jets at the entrance to the attenuating channel section. Coanda wall turns provide excellent flow turning properties when properly designed and vented. With turning radius to jet thickness ratios in the region 4-6, total turning angles of greater than 130° can be achieved without wall separation.
Acceleration rates of the air/gas flow in the discharge channel are set at levels appropriate to the desired axial strains to be applied to the attenuating fiber filaments. The necessary flow accelerations are provided through appropriate area and geometry variations incorporated into the discharge nozzle design.
Additional control of the drawn filament properties in the drawing scheme described, can be obtained by adjusting and controlling the temperature difference between the extruded polymer filament and the quenching air/gas flow utilized.
In certain applications, it may prove advantageous to provide the necessary gas/air flow turning into the spin line direction, turning this flow into the spin line direction, by combining a Coanda bend section with a suitably curved fully attached channel flow section. Thus the total required flow deflection would be achieved in separate, but connected, channel sections.
A Coanda jet is a term applied to a class of jet flows having the following features: i) a thin wall jet flow discharging over a straight or an arbitrarily curved wall surface, and in continuous contact with this surface, at one edge (side), so that entrainment at this edge is entirely eliminated; ii) the remaining (outer) jet edge is exposed to a constant pressure region when large free air entrainment occurs.
The feature of Coanda jet flows that is particularly attractive for present design purposes is the relatively very tight wall curvatures that can be negotiated without the expected separation of the jet flow from the wall surface. The wall jet may be either laminar or turbulent, however, for present applications a laminar flow is preferred.
The most important inventive aspect of this submission would appear to be as follows: i) provision for an abrupt turn and acceleration of the attenuating air flow into the spin line direction, without wall separation to accomplish the required turning flow and ii) the application of the major attenuating forces to the filaments internally in an attenuating slot. The magnitude and axial variation of the magnitude of the applied shear forces are controlled by the design of the channel section and the temperature of the supplied attenuating air flow. In particular the axial variation of the channel flow area is an important design consideration. For the formation of non-woven mats from PET the following parameters of the present invention are typical:
Extrusion die head temperature of 500/700° F.
Filament Velocity—exiting the polymer nozzle of about 0.1 to about and exiting the die slot with a velocity in the range of about 20 to about 200 feet per second. Large variations in both of these are to be expected, with a factor of plus/minus, three/four quite probable (both depend on the die design objectives).
Air Flow Velocity—exiting the polymer nozzle≈400/800 f.p.s. Again large variations can be expected (design dependent) with an upper (sonic) limit of approximately 1200/1400 f.p.s.
Filament Diameter Attenuation ratio 10:1 to 100:1.
Original Typical Filament Diameter of about 0.01-0.02 inch.
Attenuating Slot Width/Height
width—0.10-0.50 inch
height—0.25-2.50 inches
Die clearance above Table—2 to 20 ft. typical.
Temperature of Attenuating Air (Die Entrance)˜500/700° F., typical.
Temperature of Entrained Air from ambient˜+50°.
Dies—heated˜400/700° F., typical.
Two general design approaches for the air supply system required are sketched in FIGS. 2 and 4. FIG. 2 configuration does not incorporate the Coanda effect of FIG. 4 to achieve the required flow turning. In FIG. 2, turning is accomplished via duct wall design, with the polymer exterior surface providing the inner duct wall profile. The air flow in the case, is smoothly and rapidly accelerated, through a large area contraction (10:1) by means of cubic wall profiles, and simultaneously turned into the spin line at the base of the polymer nozzle. A very accurately controlled wall profile is required throughout the length of the die, to avoid air flow separation in the resulting “S” shaped nozzle.
According to the invention there is provided a melt blowing die apparatus, for extruding a plurality of polymer filaments for the manufacture of non-woven thermally insulating polymer mats, comprising: a) a die having a downwardly facing die face, defining a plurality of polymer filament extruding nozzles having axes directed to extrude the filaments vertically downwardly; b) a slot defined by vertical opposed parallel side walls evenly spaced on opposite sides of the axes, through which the filaments, extruded by the die through the nozzles, pass; and c) a pair of air supply channels located adjacent the downwardly facing die face, one on either side of the axes, each for the supply of a hot air stream vertically downwardly to and through the slot on opposite sides of said axes in contact with the filaments to attenuate the filaments passing vertically downwardly through the slot thereby to produce attenuated filaments to form the mats subsequent to downward exit from the slot.
Also according to the invention there is provided a method of melt blowing polymer filaments, for the manufacture of non-woven thermally insulating polymer mats, comprising the steps of: a) extruding a plurality of polymer filaments downwardly; b) passing the filaments centrally through a slot, having vertical parallel slot defining side walls, common to all the filaments; c) providing heated air streams on opposite sides of the filaments, to flow vertically with the filaments through the slot to attenuate the filaments while in the slot and below to produce attenuated filaments for the formation of the mats.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a diagrammatic elevation of a melt blowing apparatus according to the prior art;
FIG. 2 is a partial cross-section of the nozzle and nozzle bar defining an attenuating slot according to the present invention;
FIG. 3 is a simplified diagrammatic underview of the apparatus of FIG. 2; and
FIG. 4 is a partial cross-section of the nozzle and nozzle bar defining a Coanda bend and attenuating slot according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 2 and 3, a first embodiment of the present invention will be described. The melt blowing apparatus 20 includes a nozzle bar 36 which in conjunction with the polymer die 22 defines a suitably configured and curved, fully attached air flow channel 24 . The flow channel 24 delivers a hot air stream 26 to an extruded spin line of filaments 28 . The flow channel 24 has a generally “S” shaped contour, with the relatively large radius turn 30 directing the stream 26 across the bottom of the die 22 towards the filaments 28 . A relatively small radius turn 32 in the air flow channel 24 orients the hot air stream 26 to flow substantially parallel to the vertical direction of movement of the filaments 28 in a slot 34 . The temperature of the attenuating air stream 12 as it reaches the filaments 28 is typically from about 500 to about 700° F., and the walls of the slot are heated in a range of about 400° F. to about 700° F.
The air stream in the channel 24 are such that high accelerations take place in the large radius turn 30 , while smaller accelerations occur in the high-velocity occurring in the small radius turn 32 . The final turning of the hot air stream 26 is carried out by the relatively small radius bend 32 at the entry of the slot 34 in the nozzle bar 36 in order to obtain the desired application of air shearing forces at or near the top of the filaments 28 adjacent to the uniformly spaced array of filament extruding nozzles 38 of the die 22 .
The air entering the flow channel 24 from a pressurized air supply source is at a low velocity determined by the supply ducting and the blower/fan/compressor used to produce the necessary supply of air and volumetric capacity of the air supply system. The air supply system includes an air heating unit to provide appropriate control of the temperature in the drawing/attenuating processes in and below the attenuating slot 34 . The air discharge to the slot 34 from the air flow channel 24 is typically in the Mach number range between 0.50 and 0.75 although wider limits are not precluded.
The nozzle bar 36 also defines the attenuating slot 34 through which the filaments 28 , downwardly extruded by nozzles 38 , are drawn downwardly by the attenuating air flow. The attenuating slot 34 has a length (FIG. 3) extending laterally of the filaments symmetrically along either side of the serial plurality of nozzles 38 to provide a symmetrical consistent attenuating air flow to each of the plurality of filaments.
The major attenuating forces comprise both axial and shear forces applied to the filaments by the air flow. These forces are generated and controlled internally in the attenuating slot 34 . The axial attenuation of the filaments 28 is dependent upon the magnitude of the forces applied to the filaments 28 in the slot 34 and these forces are controlled by the configuration of the flow channel 24 and the attenuating slot 34 , in particular the axial velocity distribution and the axial temperature distribution in the parallel air therethrough.
The nozzle bar 36 and attenuating slot 34 are formed from a first and second lower nozzle plates 42 , 44 having a parallel first and second die faces 46 , 48 defining the slot 34 and symmetrically disposed on opposite sides of the filaments 28 . The nozzle plates 42 , 44 are provided with heater coils 45 to provide desired temperature control in the slot 34 . The first and second die faces 46 , 48 are spaced from one another to define the attenuating slot width W in the range of about 0.100 to about 0.50 inch. The height H of the attenuating slot, which is generally in the range of about 0.250 to about 2.50 inches, includes the height h of the parallel first and second die faces 46 , 48 of the attenuating slot 34 which are generally in the range of about 0.18 inches to about 2.0 inches.
From the extruder apparatus 2 , molten polymer 40 is forced downwardly through the nozzles 38 to form the filaments 28 , having a diameter, as they leave the nozzle, in the range of about 0.01 to 0.02 inch. The attenuating forces, both axial and shear, generated by the attenuating air flow 26 in the attenuating slot 34 to attenuate the diameter of the filaments 28 in a range of at least approximately 50:1 before the filament exits the attenuating slot 34 to be gathered on a collection belt.
As will be seen in FIG. 2, the lower face of the die 22 closely adjacent opposite sides of the row of nozzles 38 has a concave form which, together with the corresponding curves in nozzle plates 42 , 44 form the small radius turns 32 .
Turning now to FIG. 4, a second embodiment of the present invention is described. Here, each second turn 32 described above, for turning of the air stream 26 to flow in the vertical filament line direction, is replaced by a short, approximately horizontal, wall jet section and duct 50 and a Coanda bend 52 of approximately 90° having an associated duct 54 open to atmospheric pressure of the environment. The duct 54 provides a supply of air 56 to become entrained in a hot air stream supplied by duct 50 to produce the desired Coanda effect of air flow around the curved free surfaces of the Coanda bend 52 .
The duct 56 is separated from the wall jet section and duct 50 by an intermediate bar 58 which provides for the separate introduction of the air 56 from the duct 54 and the pressurized air stream 26 from duct 50 , to the entrance to the Coanda bend 52 , in the form of a thin walled jet flow emanating from the duct 50 . The thin walled jet flow exiting from the horizontal section wall jet section and duct 50 has an upper boundary which is exposed to the constant pressure via the ducting arrangement 54 from which free jet entrainment occurs. A lower boundary of the thin walled jet flow discharging from the duct over the curved free surfaces 60 of the Coanda bend 52 by the Coanda effect is caused to remain in continuous contact with the lower curved free surface 60 in order to obtain the desired turning of the pressurized hot air stream 26 around the small radius turn of the Coanda bend 52 into alignment with the filament line direction of movement. The temperature of the entrained air is generally ambient air at a temperature of about 50° F. or more.
The free Coanda surfaces 60 are located symmetrically on opposite sides of the extruded filaments 28 . On either side of the nozzles, trapped and standing vortices may be maintained above the curved free jet surfaces. Recirculation into the flow volume containing the trapped vortices must be terminated by a suitable wall contour design, prior to the convergence of the two Coanda wall jets at the entrance to the attenuating slot 64 .
Coanda bends provide excellent flow turning properties when properly designed and vented. With turning radius to jet thickness ratios in the region 4˜6:1 total turning angles of greater than 130° can be achieved without wall separation.
Nozzle bars 62 which define the free surfaces 60 together form attenuating slot 64 through which the filaments 28 are drawn down by the attenuating air flow. The attenuating slot 64 has a length extending symmetrically along either side of the plurality of nozzles 38 to provide a symmetrical consistent attenuating air flow to each of the plurality of filaments.
The major attenuating forces comprise both axial and shear forces applied to the filaments by the air flow. These forces are generated and controlled internally in the attenuating slot 64 . The axial variation of the filaments 28 is dependent upon the magnitude of the shear forces applied to the filaments and these forces are readily controlled by the configuration of the duct 50 and the attenuating slot 64 , in particular the width W and height H of the attenuating slot 64 , together with the form of the Coanda bend 52 .
The attenuating slot 64 is formed by parallel faces 65 of nozzle bars 62 which faces 65 smoothly transitioning from the outlet ends of the Coanda bends 52 . The faces define the slot width W in the range of about 0.10 inch to about 0.50 inch. The height H of the faces 65 define the height H of the attenuating slot 64 , which is in the range of about 0.25 inch to about 2.5 inches.
From the extruder 2 , the molten polymer 40 is extruded through the nozzles 38 forming the filaments 28 , having a diameter, as they leave the nozzle, in the range of about 0.01 to 0.02 inch. The attenuating forces, both axial and shear, generated by the attenuating air flow applied to the filaments 28 within the attenuating slot 64 attenuate the diameter of the filaments 28 at least in a range of approximately 50:1 before the filament exits the attenuating slot 64 and is gathered on a collection belt 10 .
Molten polymer is supplied at a suitably elevated temperature, to the nozzles 38 , and filaments 28 are discharged uniformly, vertically downward by a suitable pressurized supply system. Air/gas streams are introduced laterally from both sides. These gas streams are deflected into the spin line direction by means of two-dimensional Coanda bends (90°, as shown). The curved free jet surface, at the outer edge of the Coanda bend, entrains and accelerates the individual cylindrical filaments 28 discharged vertically above it. Once the air/gas streams are deflected into a direction parallel to the filaments' downward movement, the flow provides further important axial acceleration to the fluid filaments as the streams merge to form a single vertical discharge to atmosphere at the lower die face. This latter acceleration is attributable to the large axial shear forces applied to the attenuating fluid elements in the discharge slot. The applied shearing forces are a result of the large axial velocity difference maintained between the filaments and the air/gas stream. (The mean axial air/gas velocity in the discharge channel is approximately two orders of magnitude larger than the initial discharge velocity of the fluid filaments.)
Acceleration rates of the air/gas flow in the discharge channel are set at levels appropriate to the desired axial strains to be applied to the attenuating fiber filaments. The necessary flow accelerations are readily provided through appropriate area and geometry variations incorporated into the discharge nozzle design.
Additional control of the drawn filament properties in the drawing scheme described, can be obtained by adjusting and controlling the temperature difference between the extruded polymer filament and the quenching air/gas flow utilized.
In certain applications, it may prove advantageous to provide the necessary gas/air flow direction, turning this flow into the spin line direction, by combining a Coanda bend section with a suitably curved fully attached channel flow section. Thus the total required flow deflection would be achieved in separate, but connected, channel sections.
The air flow through the slot is preferably lamina, however, the possible use of turbulent flow in the slot is not excluded from the concept of the present invention.
The air leaving the slot is or becomes rapidly turbulent with large turbulent energy levels which applies important lateral forces to the emerging attenuated filaments to facilitate the desired entwinement of the fibers to produce the non-woven mats, batts or boards constructed upon collection of the filaments on the belt 10 .
Reference numerals
1
extruder
2
filaments
3
source of air
4
die
5
nozzle bars
6
nozzles
7
heating elements
8
valved lines
9
hot air streams
10
baffles
11
slit
12
belt
20
melt flowing apparatus
22
die
24
air flow channel
26
hot air stream
28
filaments
30
large radius turn
32
small radius turn
34
slot
36
nozzle bar
38
extruding nozzles
40
molten polymer
42
nozzle plate
44
nozzle plate
45
heating coils
46
die face
48
die face
50
duct
52
Coanda bend
54
associated duct
56
air
58
intermediate bar
60
free surface
62
nozzle bars
64
slot
65
parallel faces | A melt blowing die for extruding filaments of a polymer by a suitable configured air supply system to provide critical influencing and control over the molecular orientation, crystallinity and crystal orientation in high speed fiber spin line applications. Control of the both the magnitude and location of the applied shearing force is provided, through the design characteristics of the air supply system and, in particular, the attenuation of the filament through an attenuation slot; in one form in conjunction with the introduction of the air flow to the filament in a parallel flow caused by a Coanda bend in a second form in conjunction with a properly designed internal channel. | 3 |
BACKGROUND OF THE INVENTION
The field of this invention relates to the locating of one or more tiny holes within a block of material and principally to the locating of the holes within a block of plastic.
The subject matter of the present invention is to be discussed in conjunction with the field of medicine. However, it is to be understood that the subject matter of this invention could be utilized in numerous other fields, many of which may even be unknown to the inventor. The contemplated field of utility of this invention is directed to obtaining of an orifice member which provides for a restricted flow of a liquid through this orifice member. This restriction of flow can be of particular advantage within the medical field or within any other field where a restricted flow would be desirable.
In the constructing of any liquid conducting orifice, the side wall of the orifice would frictionally resist the flow of the liquid through the orifice. Normally, it is the intention to decrease this restriction so that the liquid can flow through the orifice with the minimum amount of resistance, therefore, a minimal amount of energy loss. However, this restriction to the flow of a liquid through an orifice can be utilized to advantage in certain environments.
The smaller the orifice, the greater the restriction. Also, the longer the orifice, the greater the restriction. If the orifice size is a thousandth of an inch or less, and the orifice separates a pair of fluid mediums with one fluid medium being at a pressure differential greater than the other, then that restriction could be utilized to maintain a certain pressure differential relationship between the two fluid mediums. There is a problem with a single orifice in that not much flow is permitted. Therefore, it is common to utilize a mass of orifices, all of which have the same size and which have the same amount of restriction. It is this mass of orifices that more effectively control and maintain the established pressure differential.
Within the field of medicine, a common disease in conjunction with eyes is glaucoma. Within the eyeball is located a liquid. This liquid is under pressure with a common pressure being approximately twenty millimeters of mercury. In glaucoma, this pressure increases and if the pressure gets too severe, the patient can actually go blind.
In the past, there have been different techniques in order to relieve this excessive pressure. A vast amount of money is spent each year on drops that are to be placed onto the eye that are minimally effective. Additionally, there have been numerous surgical techniques in order to relieve this pressure. One of the most common surgical techniques is merely to cut a hole into the eyeball which provides an outlet for some of the liquid contained in the eyeball thereby relieving the pressure. This hole is then sutured. The disadvantage of this technique is that initially the pressure of the liquid in the eyeball is decreased below the desired level to atmospheric pressure. As time goes on, the pressure will again build up back to its original level which will require a duplicating of the surgical technique.
To overcome the disadvantage of this technique, there has been manufactured a valve assembly which is to be mounted in conjunction with the eyeball and located within the hole cut into the eyeball. It is the function of the valve to be activated if a certain pressure level is exceeded and provide an escape route for some of the liquid contained within the eyeball thereby releasing the pressure. The disadvantage to this valve is that it frequently malfunctions thereby requiring replacement or complete removal of this valve unit.
Another known device has to do with utilizing a balloon operating pump as opposed to a valve. This balloon operated pump is to release liquid when the pressure is applied to the balloon. This pressure is to be applied by the natural blinking process of a human being or is to be applied by manual rubbing of one's eye. However, the patient is not sensitive to increased eye pressure, therefore, is not able to determine when it is desirable to operate the pump. Again, this type of unit is not free from malfunction although, prior to the present invention, is probably the best device available to relieve accumulated liquid pressure from the interior of an eyeball.
The present inventor discovered that if a tiny block of plastic could be manufactured with a mass of tiny, through openings, and this block of material was installed in conjunction with a hole extending into the interior of an eyeball, that depending on the size of these openings, a pressure differential can be established between the interior of the eyeball and the ambient which could be maintained without utilizing any moving parts. By varying the size of these holes, this pressure differential could also be varied. As the pressure increases, the amount of flow through the orifices increases, thereby decreasing the pressure. This is a desirable feature since not all people have the same liquid pressure within the interior of the eyeball. Therefore, if the size of the orifices could be precisely controlled, a custom designed liquid relief passage arrangement could be manufactured for that particular individual. The liquid that is conducted from the interior of the eyeball to the exterior of the eyeball is discharged naturally through the waste disposal system of the human being.
It has been impossible in the past to manufacture a block of material which had a mass of precisely sized, tiny openings. Small openings can be formed within a block of material, such as plastic, by the utilizing of a laser. However, lasers cannot, at present, make the openings that are required by the present invention as the minimal size of opening that can be formed by the laser is still too large or not of sufficient length. Therefore, another method had to be arrived at to manufacture such small openings of adequate length.
It is to be reiterated that the method of the present invention can be used to manufacture articles which are usable in other fields of endeavor. One example would be in the making of contact lenses for the eye. One of the inherent problems of a contact lens is that liquid and oxygen is normally blocked by the lens so there is no way for fluid from the exterior surface of the eyeball to penetrate to the interior surface of the lens. If a lens was manufactured in accordance with the method of the present invention, there would be a mass of tiny holes, or through openings, formed within the lens which would permit this liquid and oxygen to be conducted to the interior surface of the lens. This mass of tiny holes would not interfere with the normal vision of the lens.
SUMMARY OF THE INVENTION
The method of making a plastic article which has a plurality of small, through openings. This method has to do with the forming of an enlarged, elongated, tubular bar which is substantially hollow with this bar being constructed of a first type of plastic that is not dissolvable by a solvent. Within the hollow is located a second type of plastic that is dissolvable by a solvent. This bar is conducted vertically from an elevated position to a lowered position through a furnace which causes the lower end of the bar to melt and be drawn into a thin, elongated tubular member having a cross-sectional area less than the cross-sectional area of the bar while maintaining substantially the same proportion of first plastic to the second plastic as was contained within the bar. Sections of this tubular member are produced to a given length. A quantity of these tubular members are located in juxtaposition and bound together forming an assemblage. This assemblage is then conducted through the furnace in the manner previously described resulting in producing of a thin filament having a plurality of internally located threads of the second type of plastic. This filament is then to be cut into desired lengths and placed within a solvent bath for a period of time, sufficient to dissolve the second type of plastic producing a plurality of spaced apart small, through openings within this filament.
The primary objective of the present invention is to provide a method which permits the forming of tiny, through openings within a block of plastic material with the size of these openings being so small that they are not capable of being manufactured by any known prior art technique.
Another objective of the present invention is to utilize a method which provides for obtaining of a precise size of opening and capable of precisely varying the size of opening within a block of plastic material.
Another objective of the present invention is to provide for a method which permits relatively inexpensive manufacture of products with precisely sized, tiny openings within a plastic block of material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically depicts a portion of the method of this invention which is used to construct the elongated tubular bar of the first type of plastic with this bar being hollow;
FIG. 2 is a view similar to FIG. 1 but showing the filling of the hollow with a second type of plastic and this second type of plastic being dissolvable by a solvent;
FIG. 3 is a partly cross-sectional view depicting movement of the bar within a furnace which will cause the bar to be drawn into a substantially decreased cross-sectional area while yet maintaining in proportion and location cross-sectionally the amount of the first plastic and the second plastic;
FIG. 4 is a view similar to FIG. 3 depicting the forming into a thin filament by an assembled arrangement of the thin tubular members produced by the procedure within FIG. 3;
FIG. 5 is a view depicting the cutting of the filament produced within the FIG. 4 into desired lengths and inserting such within a solvent bath for the removal of the threads of second plastic which are laced through the now formed block; and
FIG. 6 is an isometric view of the plastic article which has been produced in accordance with the method of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Within the drawing, there is generally depicted the method of the present invention. It is to be understood that the drawing only gives a generalized representation of the procedure of the method of this invention and that in actual practice the structure that is to effect the method of this invention may be different than what is actually shown.
There are two different plastics, generally, that will be utilized. Common types of plastics that have been found to preferable would be a polymethyl methacrylate and polystyrene. Polymethyl methacrylate would probably be the preferable material for the reason that this material has been found to be an acceptable material within the medical field and would not require any material approval by any federal agency. However, it is considered to be within the scope of this invention that other material could be utilized without departing from the scope of this invention.
Of the two different plastics that are utilized, both could comprise polymethyl methacrylate. One of the polymethyl methacrylates would not be dissolvable by a solvent, with the other polymethyl methacrylate being dissolvable by a solvent. For the purpose of this invention, the plastic not dissolvable will be referred to as the first plastic and the plastic that is dissolvable by a solvent will be referred to as a second plastic.
Both the first and second plastics will have substantially identical melting points somewhere in the range of three hundred thirty degrees Fahrenheit to three hundred ninety degrees Fahrenheit. It is important that the second plastic have a melting point no greater than the first plastic. Actually, it would probably be preferable that the second plastic have a slightly less melting point than the first plastic for a reason which will become apparent further on in this specification.
The first plastic will normally come in the initial form of a mass of pellets (not shown). These pellets will be melted within a vessel 10 forming a liquid plastic 12. This liquid plastic 12 is poured into an internal chamber 14 of a mold 16. The mold 16 includes a center tube 18 which will result into the forming of a hollow cylindrical shaped hole 20 of the resultingly formed plastic bar 22 when it is removed from the mold 16. It is to be understood that, normally, the mold 16 will be placed within an injection molding machine (not shown). It is preferable that the transverse cross-sectional configuration of the bar 22 be square with the hollow 20 being circular. However, it is considered to be within the scope of this invention that the bar 22 could be another polygonal configuration, or could be a non-polygonal configuration, such as cylindrical. Generally, the length of the bar 22 is one and one-half to two feet long and being one and one-half to three inches square. The diameter of the hole 20 will normally be between one inch to one and one-half inches.
When the bar 22 has been removed from mold 16 it is permitted to cool to room temperature. It is desirable to insure that any gas and moisture that has become impregnated in the bar 22 be released. The reason for this is that gas and/or moisture will cause producing of a rejectable product. Also, at times, in the molding procedure, there may be produced a certain amount of stress within the bar 22 and it is desirable to remove this stress. In order to remove the gas, moisture and stress, the bar 22 is placed within a vacuum chamber (not shown) with a slight vacuum, such as twenty-nine inches of mercury being pulled on the bar 22. This bar 22 is stored within this chamber, which is heated to approximately two hundred fifty degrees Fahrenheit, for a certain length of time such as twenty-four hours. This procedure is to be described as THERMOVAC throughout the specification of this invention.
After the twenty-four hour period, the bar 22 is removed from the THERMOVAC chamber and permitted to again cool to room temperature. At this particular time, a quantity of the second plastic is heated within heating vessel 24 and liquefied into a liquid plastic 26. This liquid plastic is then poured into the hollow 20. Normally, this pouring into hollow 20 will be completed within an injection molding machine in order to insure the side walls of the bar 22 do not bow in an outward direction because of the application of the heat from the second plastic 26. Once the liquid second plastic 26 is cooled into a solid plastic 28, the bar 22 is then placed again within the THERMOVAC chamber for a twenty-four hour period.
After the bar 22 has been removed from the THERMOVAC chamber and cooled, it is suspended in a vertically oriented manner by an appropriate overhead suspension mechanism (not shown). The bar 22 is to be located in an elevated position. Vertically oriented means one end of the bar 22 is located directly above and in alignment with the opposite end of the bar 22 and the longitudinal center axis of the bar 22 is in alignment with the direction of the gravity force on the bar 22.
The bar 22 is then to be moved into the through opening 30 of a furnace 32. The lower portion of this furnace 32 includes a heating coil assembly 34. When the lower end of the bar 22 become located directly adjacent the coil 34, the heat will be sufficient to cause expansion of the bar 22 forming an expanded section 36. Melting of the entire cross-sectional area of the bar 22 is to occur. Bar 22 is then drawn into a substantially decreased cross-sectional size tubular member 38. Centrally disposed within this tubular member 38 is a core 40. In cross-section, the proportional size of the core 40 to the overall cross-section of the tubular member 38 is maintained the same as the relationship of hollow 20 to bar 22. It is to be understood that the core 40 is actually hollow 20 but in a small diameter. Each core 40 is filled with second plastic 28. The tubular member 38 is then to be cut into prescribed lengths such as two foot lengths 42.
The lengths 42 are again cooled and then placed within the THERMOVAC chamber for a period of time, such as four hours. A quantity of the lengths 42 are to be assembled together in juxtaposition, secured at the ends by means of a tape-like band 44 forming an assemblage 46. The assemblage 46 is basically the same size and of a square configuration as bar 22. This assemblage 46 is then again placed within the THERMOVAC chamber. The temperature at this time within the THERMOVAC chamber is increased to be just below the melting point of the plastics which will result in the tubular members 42 slightly melting together thereby bonding the assemblage 46 into a single unit. The assemblage 46 is then removed from the THERMOVAC chamber and permitted to cool. At this particular time, the bands 44 could be removed if such is deemed to be desired.
The assemblage 46 is mounted in the same manner as bar 22 was mounted in conjunction with the furnace 32. Assemblage 46 is moved through the chamber 30 of the furnace 32 with the lower end of the assemblage 46 being melted by being located directly adjacent the heating coil 34. The assemblage 46 will assume an expanded section 48 prior to being drawn into a thin filament 50. The thin filament 50 will be cut into desired lengths 52, such as a two foot length. The length 52 is to be cut by means of a cutting blade 54 into a mass of small blocks 56. Prior to being cut into the blocks 56, the filaments 52 will normally be placed in the THERMOVAC chamber again for a short period of time such as four hours. Prior to being cut into the blocks 56, the filaments 52 are to be cooled to room temperature.
The size of the blocks 56 can be any desired length. A preferable size is one-sixteenth to one-eighth inch long when used in conjunction with a device that will ultimately be mounted to treat glaucoma. Blocks 56 will actually be polished in bulk to eliminate any burrs and sharp corners prior to being deposited within reservoir 58 which contains a solvent 60. A desirable solvent 60 could be any liquid which would remove the now formed mass of threads of second plastic that extend through each block 56. Each thread is actually a smaller diametered section of second plastic 28 which is contained within the smaller diametered cores 40. A typical solvent would be within the group of xylene, trichloroethylene, acetone, methyl ethyl ketone, and methylene chloride. However, it is considered to be within the scope of this invention that other solvents could possibly be utilized. Generally, the length of time within the solvent reservoir 58 would be between five minutes to two hours.
After the submersion of the blocks 56 within the reservoir 58 which contains the solvent 60, the blocks 56 are removed and permitted to dry. The resultingly formed block 56 includes a plurality of evenly spaced apart, through openings 64, small in cross-section, which were actually cores 40. In essence, these openings 64 resemble a mass of threads formed within the blocks 62. The cross-sectional size of each of the openings 64 will generally be one-thousandth of an inch or less. The actual size of the opening 64 can be controlled by the cross-sectional thinness of the filament 52 that is produced. It is to be kept in mind that the proportional size of each of the cores 40 of each tubular member 42 is maintained in conjunction with the filament 52. So, therefore, the thinner the filament 52 that is produced, the smaller the block 62 and, hence, smaller the opening 64. It is not at all uncommon to produce two hundred twenty-five openings 64 within an eighth inch square block 62.
It is envisioned that different techniques could be utilized to eliminate the core plastic 40. Possibly, by utilizing a slightly different melting temperature for the core plastic 40 relative to the first plastic, and by carefully raising of the temperature of each of the blocks 56 that the core plastic can be eliminated by melting leaving intact the remaining portion of the block 56 thereby producing the block 62. At the present time, there is no known method to produce such small, through openings 64 by physically cutting either by drilling or by a laser. | The method of making a plastic article having a plurality of small openings which utilizes a plurality of thin plastic tubular members combined together in a side-by-side relationship forming an assemblage. Each tubular member has an exterior layer of a first plastic and a core of a second plastic. The second plastic is to be dissolvable by a solvent. This assemblage is passed through a furnace with the result that the assemblage is drawn into a thin filament. Once cooled, the thin filament is cut into segments of a desired length and these segments are placed within a solvent bath for a sufficient period of time in order to affect complete removal of the second type of plastic resulting in producing of a plurality of small, through openings within each section. | 1 |
FIELD OF THE INVENTION
The following invention relates to implants which are configured to be placed within an intervertebral space between adjacent spinal vertebrae after a disk has been removed from the space and to facilitate fusion of the vertebrae together. More particularly, this invention relates to implants which can be implanted posteriorly in either a minimally invasive or open manner and spread vertebrae adjacent the intervertebral space away from each other to recreate the lumbar lordosis and support the vertebrae while they fuse together.
BACKGROUND OF THE INVENTION
Spinal fusion procedures are known as an effective treatment for certain spinal conditions. In general, such spinal fusion procedures may involve removal of a disk within an intervertebral space between two adjacent vertebrae. After the disk has been removed an implant can be located within the intervertebral space to push the vertebrae apart. By pushing the vertebrae apart, ligaments and other body structures surrounding the vertebrae are placed in tension and tend, along with the implant, to securely hold the two vertebrae in fixed position relative to each other. It is important to restore as much as possible the height of the intervertebral space. It is also important to restore the angle or “lordosis” of the intervertebral space. Finally, fusion material is placed within the intervertebral space which induces bone growth within the intervertebral space, effectively fusing the two vertebrae together with the implant typically remaining embedded within this fused vertebra combination.
Placement of the implant within the intervertebral space is accomplished in one of two general ways. First, the intervertebral space can be accessed anteriorly by performing abdominal/thoracic surgery on the patient and accessing the intervertebral space from a front side of the patient. In this anterior procedure major abdominal/thoracic surgery is typically involved. However, the intervertebral space can be generally accessed anteriorly, such that the risk of injury to the nerves is generally reduced and the surgeon has greater flexibility in positioning the implant precisely where desired.
Second, the implant can be inserted posteriorly. Direct posterior access to the intervertebral space requires moving the spinal nerves within the spinal canal towards the midline and can result in nerve injury or scarring. Implantation in the intervertebral space can also be accessed from a location spaced to the left or right side of the spinal column and at an angle extending into the intervertebral space. This approach avoids the spinal canal. A minimally invasive method using small incisions can be used but is must be carefully performed to avoid sensitive spinal structures. Additionally, implants of a smaller size are typically required due to the small amount of clearance between vertebral structures. Hence, the amount of spreading of the vertebrae with a posterior implant is often less than adequate. Additionally, portions of the vertebrae typically need to be at least partially carved away to provide the access necessary to insert the implants posteriorly into the intervertebral space.
Implants for the intervertebral space come in a variety of different configurations, most of which are designed for anterior implantation. One known prior art implant is described in detail in U.S. Pat. No. 5,800,550 to Sertich. The Sertich implant is configured to be implanted posteriorly and comes in two pieces. Two separate incisions are made on either side of the spine and the pieces of the overall implant are inserted generally parallel to each other, but can be angled slightly away from a parallel orientation. The Sertich implant pieces have a rectangular cross section and an elongate form. The pieces are initially implanted with a lesser dimension oriented vertically so that the pieces can easily enter the intervertebral space. The pieces are then rotated 90° so that the greater dimension is rotated to vertical, tending to spread the vertebrae vertically to enlarge the intervertebral space.
The implant taught by Sertich is not entirely desirable. Because the Sertich implant involves two entirely separate pieces, they do not stabilize each other in any way and hence provide a less than ideal amount of vertebral stabilization. Additionally, the relatively parallel angle at which they are implanted typically requires removal of portions of the vertebrae and retraction of the spinal nerves to properly implant the pieces of the Sertich implant. If the two pieces of the implant are angled more towards each other, they tend to decrease further in the stability that they provide to the vertebrae. Also, the Sertich implant pieces have a size which requires a relatively large incision to insert into the intervertebral space.
Accordingly, a need exists for a posteriorly placed intervertebral space implant which has a small cross-sectional profile at insertion and yet can provide a large amount of displacement between adjacent vertebrae once placed. The implant must expand sufficiently far apart to restore the height of the intervertebral space and act substantially as a single rigid structure within the intervertebral space after implantation is completed. Such an invention would additionally benefit from being capable of having a greater height in an anterior region such that lordosis can be achieved in an amount desired by the surgeon with an anterior side of the intervertebral space larger than a posterior side of the intervertebral space.
SUMMARY OF THE INVENTION
This invention is an intervertebral space implant which is configured to be implanted posteriorly in a minimally invasive or open surgical procedure. The implant includes two separate segments including a primary segment and a secondary segment. The primary segment and the secondary segment enter the intervertebral space through separate incisions on either side of the spine and along paths which intersect within the intervertebral space. To enhance a spreading of the intervertebral space with the implant, the segments have a height between a bottom surface and a top surface which is greater than a lateral width. The segments can thus be introduced into the intervertebral space with the top and bottom surfaces spaced laterally from each other and then be rotated 90° so that the top surface is above the bottom surface and a height of the segments is maximized.
Portions of the primary segment and the secondary segment adjacent where the segments intersect are removed to allow the segments to lie in a substantially common plane. Preferably, the primary segment includes a tunnel passing laterally through the primary segment near a midpoint thereof. The secondary segment is provided with a neck near a midpoint thereof which has a lesser height than other portions of the secondary segment. The tunnel is sized so that the secondary segment can pass through the tunnel in the primary segment and then be rotated with the neck of the secondary segment within the tunnel of the primary segment.
After the secondary segment has been rotated the two segments are interlocking together in a crossing pattern forming the implant assembly of this invention. Hence, the implant assembly of this invention provides the advantage of having a relatively low profile for insertion posteriorly in a minimally invasive manner and yet results in an overall implant assembly which has separate segments interlocking together to form a single substantially rigid implant assembly to maximize stabilization of the vertebrae adjacent the intervertebral space.
Additionally, the segments are formed in a manner which facilitates height expansion of the segments after implantation, especially at distal ends of the segments. Such additional height expansion further stabilizes vertebrae adjacent the intervertebral space and provides lordosis to the intervertebral space.
Specifically, the primary segment is preferably formed with a top structure separate from a bottom structure which pivot relative to each other, such as about a hinge. A passage passes between the top structure and the bottom structure. A shim can pass along the passage and cause a distal end of the primary segment to be expanded in height when the shim enters a tapering end portion of the passage. The distal end of the primary segment is thus expanded in height to an extent desired by a surgeon to provide a desirable amount of “lordosis” for the spinal fusion procedure.
Similarly, the secondary segment is preferably formed from a top jaw and a bottom jaw which can pivot relative to each other, such as about a hinge. A bore passes between the top jaw and the bottom jaw and a wedge is caused to move within the bore in a manner causing the top jaw and the bottom jaw to be spaced apart and causing a height of the secondary segment to be increased at a first distal end of the secondary segment.
The insertion of the segments themselves as well as the movement of shims and wedges within the segments to enhance their height is all accomplished through a small posterior incision. A variety of different hinge arrangements, shim and wedge arrangements and other structural variations are provided for the segments of the implant assembly.
OBJECTS OF THE INVENTION
Accordingly, a primary object of the present invention is to provide an implant for an intervertebral space which can be implanted posteriorly and still provide a substantially rigid implant assembly for spreading and stabilization of the vertebrae adjacent the intervertebral space.
Another object of the present invention is to provide an implant assembly having separate segments which are as low profile as possible so that posterior implantation can be accomplished in as minimally invasive a surgical procedure as possible.
Another object of the present invention is to provide an implant assembly for an intervertebral space which is initially entered into the intervertebral space in separate segments which are later interlocked together.
Another object of the present invention is to provide an intervertebral space implant assembly which can be adjusted in height to maximize a size of the intervertebral space generally and to allow for selective height adjustment within different portions of the intervertebral space, to provide a surgeon with a maximum amount of flexibility in positioning vertebrae adjacent the intervertebral space as precisely as desired.
Another object of the present invention is to provide an implant assembly which can be located within an intervertebral space with little risk of damage to sensitive surrounding tissues.
Other further objects of the present invention will become apparent from a careful reading of the included drawing figures, the claims and detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a human spine with an intervertebral space containing the implant assembly of this invention.
FIGS. 2-5 are top plan views taken along line 5 — 5 of FIG. 1 illustrating the four basic steps involved in the implantation of the implant assembly of this invention.
FIG. 6 is a side elevation view of a primary segment of the implant assembly with hollow interior details shown in broken lines.
FIG. 7 is a top plan view of that which is shown in FIG. 6 .
FIG. 8 is a proximal end elevation view of that which is shown in FIG. 6 .
FIG. 9 is a full sectional view of that which is shown in FIG. 6 and with a guide wire and shim of this invention shown entering a passage within the primary segment to expand a height of the primary segment adjacent a distal end of the primary segment.
FIG. 10 is a full sectional view of that which is shown in FIG. 9 after the shim has been fully advanced into the passage of the primary segment of this invention so that the height of the distal end of the primary segment has been enhanced.
FIG. 11 is a full sectional side elevation view of a secondary segment of the implant assembly of this invention along with one form of a tool utilized to enhance a height of a distal first end of the secondary segment of the implant assembly of this invention.
FIG. 12 is a top plan view of that which is shown in FIG. 11 with interior details shown with broken lines.
FIG. 13 is a proximal second end view of that which is shown in FIG. 12 .
FIG. 14 is a full sectional view of that which is shown in FIG. 11 after a wedge has been fully advanced to enhance a height of the distal first end of the secondary segment.
FIG. 15 is a top plan view of a tongs identifying one form of tool utilizable to implant the primary segment or the secondary segment of this invention.
FIG. 16 is a side elevation view of an alternative embodiment of that which is shown in FIG. 6 showing an offset hinge.
FIG. 17 is a proximal end view of that which is shown in FIG. 16 .
FIG. 18 is a proximal end view of a second alternative embodiment of the primary segment of this invention.
FIG. 19 is a side elevation view of a third alternative embodiment of a primary segment of the implant assembly of this invention with interior details shown with broken lines.
FIG. 20 is a distal end view of that which is shown in FIG. 19 .
FIG. 21 is a side elevation view of that which is shown in FIG. 19 after full advancement of an alternative shim for use with the third alternative primary segment of the implant assembly of this invention.
FIG. 22 is a full sectional side elevation view of a fourth alternative embodiment of a primary segment of the implant assembly of this invention showing a guide wire with both a shim advanced past a tunnel in the fourth alternative primary segment and a proximal shim and expanding hinge to allow height expansion of a proximal end of the fourth alternative primary segment of the implant assembly of this invention.
FIG. 23 is a full sectional side elevation view of that which is shown in FIG. 22 after insertion of the proximal shim of this embodiment into a proximal recess to enhance the proximal height of the fourth alternative primary segment of the implant assembly of this invention.
FIGS. 24-27 are sectional and side elevation views of an expanding hinge of the fourth alternative primary segment of the implant assembly of this invention revealing in detail the various stages in the operation of this expanding hinge.
FIGS. 28-30 are top plan views of alternatives of the implant assembly of this invention showing how various beveled surfaces and relief notches can be provided adjacent the tunnel in the primary segment and the neck in the secondary segment to facilitate rotation of the secondary segment within the tunnel of the primary segment and to facilitate orientation of the secondary segment at an angle relative to the primary segment other than purely a perpendicular angle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral 10 (FIG. 1) is directed to an implant assembly for implantation into an intervertebral space S between adjacent vertebrae V after a disk D has been removed from the intervertebral space S. A primary segment 20 and a secondary segment 60 are implanted along separate pathways but interlock together within the intervertebral space S to form a single implant assembly 10 . The resulting assembly 10 securely stabilizes the vertebrae V adjacent the intervertebral space S for spinal fusion of the vertebrae V together.
In essence, and with particular reference to FIGS. 1-5, the basic details of the implant assembly 10 are described. The implant assembly 10 includes a primary segment 20 (FIG. 2) and a secondary segment 60 (FIG. 4 ). The primary segment 20 is elongate in form extending along a primary axis A. The primary segment 20 is preferably higher than it is wide (compare FIG. 2 with FIG. 3 ), thus having a rectangular cross-section. The primary segment 20 can thus be inserted on its side into the intervertebral space (along arrow C of FIG. 2) and then rotated within the intervertebral space (along arrow F of FIG. 3) to help spread vertebrae V adjacent the intervertebral space S away from each other. The primary segment 20 additionally includes a tunnel 30 (FIG. 2) passing laterally through the primary segment 20 .
The secondary segment 60 (FIG. 4) is elongate and has a contour generally similar to that of the primary segment 20 . However, the secondary segment 60 includes a neck 70 rather than the tunnel 30 of the primary segment 20 . The secondary segment 60 has a cross-sectional size similar to a size of the tunnel 30 . This size allows the secondary segment 60 to be inserted along secondary axis B (in the direction identified by arrow E of FIG. 4) through the tunnel 30 in the primary segment 20 . The secondary segment 60 can later be rotated (along arrow G of FIG. 5) in a manner similar to the rotation of the primary segment 20 so that a height of the secondary segment 60 is oriented vertically and maximizes a spacing of vertebrae V adjacent the intervertebral space S. The segments 20 , 60 interlock together to form the implant assembly 10 with the segments 20 , 60 stabilizing each other and allowing the implant assembly 10 to stabilize the intervertebral spaces in which the assembly 10 is implanted.
More specifically, and with particular reference to FIGS. 6-10, details of the primary segment 20 according to a preferred embodiment of this invention are described. The primary segment 20 is an elongate substantially rigid construct formed from a top structure 22 and a bottom structure 24 which are pivotably joined together, such with a hinge 25 . The hinge 25 can take on many different forms to provide the basic function of allowing the top structure 22 and the bottom structure 24 to be pivoted relative to each other.
The primary segment 20 extends from a distal end 26 to a proximal end 28 . A guide wire stop 27 can be optionally included with the bottom structure 24 at the distal end 26 and extend up beyond the top structure 22 .
The tunnel 30 passes laterally through the primary segment 20 between a top surface and a bottom surface of the primary segment 20 . The tunnel 30 includes a top 32 preferably substantially parallel to a bottom 34 and sides 36 extending between the bottom 34 and the top 32 . The tunnel 30 preferably has dimensions similar to exterior dimensions of the primary segment 20 itself, but rotated 90°. The tunnel 30 is thus sized to allow secondary segments 60 with dimensions similar to the primary segment 20 to pass laterally through the tunnel 30 during formation of the implant assembly 10 of this invention within the intervertebral space S (FIGS. 1 - 5 ).
A passage 40 extends longitudinally within the primary segment 20 and between the top structure 22 and the bottom structure 24 . The passage 40 includes an entrance 42 at the proximal end 28 of the primary segment. The passage 40 additionally includes a roof 44 preferably substantially parallel to and spaced from a floor 46 . Preferably, the passage 40 has a constant cross-section from the entrance 42 to a location where the passage 40 intersects the tunnel 30 . The passage 40 preferably continues beyond the tunnel 30 and toward the distal end 26 of the primary segment 20 . However, portions of the passage 40 on a distal side of the tunnel 30 preferably taper to form a tapering end 48 of the passage 40 . A step 49 is preferably located in the passage 40 directly adjacent the tunnel 30 .
The passage 40 is configured to receive a shim 50 therein. The shim 50 (FIG. 9) preferably has a rectangular cross-section which generally fills the passage 40 (FIG. 8) so that the shim does not rotate. The shim 50 preferably includes a tip 52 which is of lesser height than a tail 54 . A central pathway 56 preferably passes through the shim 50 . A guide wire 58 can be passed entirely through the passage 40 up to the stop 27 (along arrow H of FIG. 9) and then the shim 50 threaded onto the guide wire 58 . The shim 50 can then be easily advanced along the guide wire 58 (arrow J of FIG. 9) and directed into the passage 40 . When the shim 50 reaches the tapering end 48 of the passage 40 , with the assistance of an appropriate shim pushing tool, the shim 50 causes the top structure 22 and bottom structure 24 of the primary segment 20 to be expanded away from each other (about arrow K of FIG. 10) and a height of the primary segment 20 to be enhanced at the distal end 26 of the primary segment 20 .
Such distal end 26 height expansion for the primary segment 20 is desirable in many cases to provide lordosis to the intervertebral space S. Specifically, lordosis is a orientation for the intervertebral space S where an anterior edge of the intervertebral space S has a greater height than a posterior edge of the intervertebral space S. Such lordosis can be provided to a varying degree depending on the desires of the medical practitioner. With this invention the shim 50 is advanced an amount desired through the passage 40 of the primary segment 20 to provide an amount of lordosis which is desirable in the judgment of the medical practitioner. The segment 20 can be custom designed to provide the lordosis desired or can be variably expandable for adjustment during implantation.
With particular reference to FIGS. 11-14, details of a preferred embodiment of the secondary segment 60 are described. The secondary segment 60 preferably has a general exterior contour similar to that of the primary segment 20 . Also, the secondary segment 60 is preferably divided into a top jaw 62 and a bottom jaw 64 which are pivotably connected together, such as at a hinge 65 . As with the primary segment 20 , the hinge 65 can take on a variety of different configurations. The secondary segment 60 extends from a first distal end 66 to a second proximal end 68 .
The secondary segment 60 includes a neck 70 with two preferably substantially parallel surfaces 72 and side walls 74 extending between the parallel surfaces 72 of the neck 70 and top and bottom surfaces of the secondary segment 60 . The side walls 74 can be perpendicular to the parallel surfaces 72 (as depicted generally in FIG. 4) or can be beveled (as shown in FIG. 11 ). The parallel surfaces 72 are located closer to each other than a distance between top and bottom surfaces of the secondary segment 60 . The parallel surfaces 72 need not be precisely parallel, but benefit from having a lesser height than that of the top and bottom surfaces of the secondary segment 60 so that the neck 70 of the secondary segment 60 is an open region then can reside within the tunnel 30 or other open region in the primary segment 20 after rotation of the secondary segment 60 into an orientation with the top surface and the bottom surface vertically aligned along with top and bottom surfaces of the primary segment 20 (FIG. 5 ). Preferably, the neck 70 is located near a midpoint between the distal first end 66 and the proximal second end 68 of the secondary segment 60 .
The width between lateral sides of the secondary segment 60 is preferably similar to a height of the neck 70 and a height of the tunnel 30 in the primary segment 20 for a tight fit within the tunnel 30 both before and after rotation (about arrow G of FIG. 5 ). The hinge 25 in the primary segment 20 , general slight flexibility of the segments 20 , 60 and possible slight additional clearances can provide the relief necessary to allow the secondary segment 60 to rotate with the neck 70 within the tunnel 30 . Preferably, the secondary segment 60 tends to snap into its final position so that the segments 20 , 60 are securely interlocked together.
To provide lordosis to the intervertebral space S, the secondary segment 60 is configured to allow height expansion, particularly at the distal first end 66 . Specifically, the secondary segment 60 includes a bore 80 passing longitudinally from the proximal second end 68 , at least part of the way toward the distal first end 66 . The bore 60 includes a pin 82 therein which includes a threaded end 83 at an end thereof closest to the distal first end 66 of the secondary segment 60 . An access end 84 of the pin 82 is opposite the threaded end 83 and closest to the proximal second end 68 of the secondary segment 60 . A wrench 85 having one of a variety of different configurations (FIG. 11) can be utilized to cause the pin 82 to rotate by interaction of the wrench 85 with the access end 84 of the pin 82 . Preferably, the bore 80 is slightly smaller adjacent the proximal end 68 to keep the pin 82 from sliding toward the proximal end 68 within the bore 80 .
A wedge 86 is located within a tapering recess 87 in the bore 80 . The wedge 86 is preferably cylindrical and includes a threaded hole extending perpendicularly through curving sides of the wedge into which the threaded end 83 of the pin 82 is located. Hence, when the pin 82 is rotated by rotation of the tool 85 (along arrow L of FIG. 11) the threaded end 83 of the pin 82 causes the wedge 86 to travel toward the distal first end 66 of the secondary segment 60 (along arrow M of FIG. 14 ). As the wedge 86 travels toward the distal first end 66 and through the tapering recess 87 , the top jaw 62 and bottom jaw 64 are spread vertically (along arrow N of FIG. 14 ), enhancing a height of the secondary segment 60 .
While the primary segment 20 and secondary segment 60 are shown with unique systems for vertically expanding top and bottom portions of the segments 20 , 60 , it is noted that these systems are merely one currently most preferred embodiments of a vertical height enhancement system for the segments 20 , 60 . In fact, a variety of different systems could be utilized to enhance the vertical height of the segments 20 , 60 after implantation.
Most preferably, the segments 20 , 60 have a height between a top and bottom surface approximately twice a width between lateral sides of the segments 20 , 60 . A tongs 90 (FIG. 15) can be utilized to properly place the segments 20 , 60 within the intervertebral space S (FIG. 1 ). Tongs 90 typically have fingers 92 which have tips 93 with a width similar to half of the lateral width of the segments 20 . In this way, the segments 20 , 60 could be grasped on lateral sides with the tips 93 of the fingers 92 of the tongs 90 and the segments 20 , 60 can be advanced through a tubular cannula with the tubular cannula having a diameter similar to a height of the segments 20 , 60 between top and bottom surfaces of the segments 20 , 60 . The tongs 90 might include a pivot 94 with handles 96 at ends of the tongs 90 opposite the fingers 92 for releasably grasping the segments 20 , 60 .
Alternatively, the segments 20 , 60 could be grasped at their proximal ends 28 , 68 through an appropriate attachment mechanism inboard of the top and bottom surfaces and lateral surfaces of the segments 20 , 60 so that the tongs 90 or other placement tool would not add to a cross-sectional diameter needed for the cannula through which the segments 20 , 60 would be passed.
With particular reference to FIGS. 16 and 17, details of an alternative offset hinge 102 are described. Such an offset hinge 102 is shown on a first alternative primary segment 100 . However, the offset hinge 102 could similarly be located on a secondary segment such as a modification of the secondary segment 60 (FIGS. 11 - 14 ). The offset hinge 102 advantageously allows a single pintle to pass through all leaves of the offset hinge 102 (FIG. 17 ). The offset hinge 102 thus avoids the necessity of two partial pintles on opposite sides of a passage 40 (FIG. 8) or bore 80 (FIG. 13 ). Otherwise, the alternative primary segment 100 of FIGS. 16 and 17 is similar to the primary segment 20 of the preferred embodiment of the implant assembly 10 of this invention.
FIG. 18 shows a second alternative primary segment 110 featuring a split hinge 112 . This split hinge 112 on the second alternative primary segment 110 is generally similar to the hinge 25 of the primary segment 20 of the preferred embodiment (FIG. 8 ). However, the overlapping leaves place the pintles of the split hinge 112 in a slightly different position. The second alternative primary segment 110 and split hinge 112 of FIG. 8 illustrate one of the many different hinge configurations which the segments 20 , 60 of the implant assembly 10 of this invention can have to effectively allow top and bottom portions of the segments 20 , 60 to move relative to each other.
While the material forming the segments 20 , 60 would typically be some form of surgical grade bio-compatible stainless steel or other material, it is conceivable that the material forming the segments 20 , 60 could be a form of hydrocarbon polymer or other plastic material, or a metallic material which has some appreciable flexibility characteristics. If the segments 20 , 60 are made from such materials or can be machined to have sufficiently thin connection between the top and bottom portions of the segments 20 , 60 , the hinges 25 , 102 , 112 of the various embodiments of this invention could be replaced with the top and bottom portions of the segments 20 , 60 merely flexing relative to each other sufficiently to allow the height expansion at the distal ends 26 , 66 of the segments 20 , 60 so that an appropriate amount of lordosis can be provided to the intervertebral space S (FIG. 1 ).
With particular reference to FIGS. 19-21 details of a third alternative primary segment are described. This third alternative primary segment 120 features an offset hinge 122 similar to the offset hinge 102 of the first alternative primary segment 100 (FIG. 16 ). The third alternative primary segment 120 additionally includes undulating overlapping tapering surfaces 124 for portions of the top and bottom structures of the third alternative primary segment 120 adjacent the distal end. These undulating overlapping tapering surfaces 124 can be spread apart by longitudinal advancement of a first alternative shim 126 which is preferably cylindrical and as wide as the entire segment 120 . As the first alternative shim 126 is advanced (along arrow P of FIG. 19) it passes through a series of steps corresponding with different stages of lordosis which can be provided to the intervertebral space S (FIG. 1 ).
Because the tapering surfaces 124 undulate, a series of locations are provided where the first alternative shim 126 can come to rest. Varying degrees of height adjustment corresponding to various different degrees of lordosis can thus be provided to the intervertebral space S (FIG. 1 ). The first alternative shim 126 can be advanced by being pushed along through an access passage 128 with any appropriate form of pushing tool, or could be advanced with a threaded pin similar to the advancement of the wedge 86 along the pin 82 of the secondary segment 60 of the preferred embodiment.
Because the tapering surfaces 124 overlap, a greater amount of height increase at the distal end of the third alternative primary segment 120 is provided (see FIG. 20 ). This third alternative primary segment 120 height magnification system could be fitted on an alternative secondary segment having a neck rather than a tunnel in a relatively straightforward fashion due to the relatively low profile passage 128 which could pass through a neck without compromising a strength of the neck in such an alternative secondary segment. Hence, this height magnification system is merely illustrated in the context of primary segment for convenience, but could be equally well incorporated into a secondary segment.
With particular reference to FIGS. 22-27, details of a fourth alternative primary segment are described. The fourth alternative primary segment 130 is configured to allow height adjustment both at a distal end of the fourth alternative primary segment 130 and at a proximal end of the fourth alternative primary segment 130 . Specifically, the top and bottom portions of the fourth alternative primary segment 130 are preferably joined together with an expanding hinge 132 .
Function of the expanding hinge is shown in detail in FIGS. 24-27. The expanding hinge 132 includes two separate pintles 134 on opposite sides of a longitudinal passage extending through the fourth alternative primary segment 130 . The pintles 134 reside within slots 136 . Hence, the expanding hinge 132 allows both rotation and vertical expansion (along arrow R of FIGS. 25 and 26) while still holding the top and bottom portions of the fourth alternative primary segment 130 together.
A longitudinal passage passing through the fourth alternative primary segment includes a proximal recess 140 near a proximal end of the fourth alternative primary segment 130 . A proximal shim 142 can be advanced along a guide wire in a manner similar to the advancement of the shim 50 of the primary segment 20 of the preferred embodiment. The proximal shim 142 is preferably configured with a contour matching that of the proximal recess 140 . Hence, as the proximal shim 142 is advanced into the passage (along arrow Q of FIG. 22 ), the proximal shim 142 expands the top and bottom portions of the fourth alternative primary segment 130 away from each other until the proximal shim 142 rests within the proximal recess 140 .
As an alternative to providing the proximal recess 140 , the proximal shim 142 could merely have a tapering contour (shown in FIG. 22) and the friction between tapering surfaces of the proximal shim 142 and upper and lower surfaces of the pathway within the fourth alternative primary segment 130 could allow the proximal shim 142 to remain in a position where it has been advanced unless specific forces are applied to the proximal shim 142 .
As shown in FIG. 22, a shim similar to the shim 50 of the preferred embodiment would first be advanced along the guide wire into the tapering end of the passage within the fourth alternative primary segment 130 . The proximal shim 142 would then be advanced into the passageway. Hence, the fourth alternative primary segment 130 experiences height magnification both adjacent a distal end and adjacent the proximal end of the fourth alternative primary segment 130 . The proximal shim 142 could similarly be used with an expanding hinge 132 fitted into the proximal second end 68 of the secondary segment 60 to give the secondary segment 60 proximal end 68 height adjustability.
FIG. 28 shows a fifth alternative primary segment 150 which uniquely includes beveled tunnel sides 152 . These beveled tunnel sides 152 allow a second alternative secondary segment 155 to pass through the tunnel in a non-perpendicular direction. Specifically, the secondary segment 155 can be angled relative to the fifth alternative primary segment 150 by an angular amount (arrow X of FIG. 28) which can be less than or greater than 90°, rather than only exactly 90°. Angle X in FIG. 8 is shown at approximately 60° but could be reduced to as little as 45° or less and still allow the secondary segment 155 to pass through the tunnel in the fifth alternative primary segment 150 without being blocked by the beveled tunnel sides 152 . The beveled tunnel sides 152 are shown angled approximately 45° away from an orientation perpendicular to a long axis of the fifth alternative primary segment 150 . However, the angles of the beveled tunnel sides 152 and the angle X that the secondary segment 155 shares relative to the fifth alternative primary segment 150 could be increased or decreased depending on the needs of the medical practitioner for the implant assembly 10 .
The second alternative secondary segment 155 preferably includes a relief bevel 156 (FIG. 28) which allows a side wall of the neck in the second alternative secondary segment 155 to come into contact with a side surface of the first alternative primary segment 150 after the second alternative secondary segment 155 has been rotated into its final position. The relief bevel 156 thus allows the second alternative secondary segment 155 and the fifth alternative primary segment 150 to more completely stabilize each other in a fully interlocking fashion so that the implant assembly 10 stabilizes the intervertebral space S (FIG. 1) as completely as needed.
A sixth alternative primary segment 160 is shown in FIG. 29 which includes relief notches 162 in sides of the sixth alternative primary segment 160 adjacent the tunnel. The relief notches 162 are an alternative to the relief bevel 156 of the embodiment of FIG. 28 . Specifically, FIG. 29 illustrates how either the relief bevel 156 can be provided on the second alternative secondary segment 155 or relief notches 162 can be provided as in the sixth alternative primary segment 160 so that complete rotation of the third alternative secondary segment 164 can be achieved without the necessity of the relief bevel 156 of the second alternative secondary segment 155 . Of course a combination of the relief bevel 156 and the relief notches 162 could be resorted to so that abutting surfaces of the primary segment and the secondary segment could mesh together in a manner providing stability for the overall implant assembly 10 .
A fourth alternative secondary segment 170 is shown in FIG. 30 along with the fifth alternative primary segment 150 . This implant assembly shown in FIG. 30 is shown with the first alternative primary segment 150 in section and clearly illustrating how the fourth alternative secondary segment 170 can fit through the tunnel in the fifth alternative primary segment 150 at an angle X (FIG. 28) other than perpendicular and be rotated, about arrow T, and to the final position such as that shown in FIG. 28 .
It can be seen from FIG. 30 that not all of the beveled tunnel sides 152 are strictly necessary for the passage of the fourth alternative secondary segment 170 through the tunnel in the fifth alternative primary segment 150 . By providing the beveled tunnel sides 152 in two directions, the fifth alternative primary segment 150 becomes reversible. However, inclusion of both beveled tunnel sides 152 would not be absolutely necessary. Rather, only one beveled tunnel side 152 could be provided on each side of the tunnel and other beveled tunnel sides 152 could be eliminated. Particularly, and as shown in FIG. 30, the beveled tunnel sides 152 which include reference numerals thereon could be removed and the fourth alternative secondary segment 170 could still pass through the tunnel in the fifth alternative primary segment 150 successfully.
Selective relief bevels 172 similar to the relief bevels 156 (FIG. 28) could be provided on some of the neck side walls, but would not need to be on all neck side walls. The selective relief bevels 172 would come to rest adjacent sides of the primary segment 150 after rotation about arrow T and provide enhanced stability between the segments 150 , 170 .
This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this disclosure. For instance, while the primary segment 20 and the secondary segment 60 are described in the preferred embodiment as being expandable, a simplified variation of this invention would not require such expandability. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. | An implant assembly 10 is provided for surgical implantation into an intervertebral space S, such as for stabilization of vertebrae V adjacent the intervertebral space S during a spinal fusion procedure. The implant assembly 10 includes a primary segment 20 separate from a secondary segment 60 . These segments 20, 60 are elongate and of sufficiently small cross-section that they can be implanted posteriorly in a minimally invasive manner. The segments 20, 60 preferably have a rectangular cross-section so that they can be inserted on a side into the intervertebral space S and then rotated into a maximum height orientation to widen the intervertebral space S. The segments 20, 60 interlock together at an intersection there between. The primary segment 20 preferably includes a tunnel 30 and the secondary segment 60 preferably includes a neck 70 with the tunnel 30 and neck 70 sized complementally so that the segments 20, 60 stabilize each other where they intersect with the neck 70 within the tunnel 30 . The entire implant assembly 10 is thus provided which both widens and supports the intervertebral space S and is sufficiently rigid to provide adequate support for the intervertebral space S as the vertebrae V are fusing together. The segments 20, 60 are fitted with height expansion systems which can be accessed after implantation of the segments 20, 60 so that height of the segments 20, 60 can be further increased, particularly at distal ends 26, 66 of the segments 20, 60 , such that the intervertebral space S can be provided with a desirable amount of lordosis. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional application of U.S. application Ser. No. 14/043,510 filed Oct. 1, 2013 and entitled SYSTEM AND METHOD FOR LENGHTING AN EXISTING SPINAL SUPPORT STRUCTURE, the disclosure of which is hereby incorporated by reference into the present application.
BACKGROUND
[0002] The present disclosure relates to spinal fusion surgery and more particularly pertain to a new system and method for lengthening an existing spinal support structure for facilitating a surgical procedure for revising by extending a previous spinal support construct used, for example, for spinal vertebral fusion.
[0003] Conventional spine surgeries, such as spinal fusion surgery, involves the installation of a rod connected to screws mounted on individual spinal vertebrae, and in the past required forming an incision in the tissue of the patient that extended for at least the distances between the most distant vertebrae to which the rod was to be mounted, and typically at least the length of the rod to be installed. More recently, a minimally invasive technique has been developed and used in which a number of smaller incisions are formed in the back, rather than the traditional single long incision, with each incision generally corresponding to one of the locations of the pedicle screw to be placed. One or more additional incisions may be formed to permit lengthwise insertion of the rod into a position that is adjacent to the screw, so that the rod may be attached to the previously mounted screws.
SUMMARY
[0004] In one aspect, the present disclosure relates to a system for interfacing a first support rod to a second support rod, and may comprise a rod interface device configured to receive a portion of a first support rod and grip a portion of a second support rod to secure the second support rod to the first support rod. The rod interface device may comprise a frame having a bottom wall and a perimeter wall extending from the bottom wall to partially define an interior configured to receive a portion of the first support rod therein. The rod interface device may also comprise a pair of gripping jaws movably mounted on the frame such that the gripping jaws are movable with respect to each other between a gripping position in which the second rod is gripped by the jaws and a release position in which the second rod is released from any grip of the gripping jaws.
[0005] In another aspect, the disclosure relates to a system for interfacing first support rod to a second support rod, and may comprise a screw interface device configured to receive a portion of a first support rod and being configured to mount on a head portion of a screw. The screw interface device may comprise a screw mount element configured to be removably mounted on the head portion of the screw, the screw mount element being insertable into the cavity to secure the second support rod in the cavity. The screw interface device may also comprise a rod mount element mounted on the screw mount element, with the rod mount element defining a pocket for receiving a portion of the first support rod.
[0006] In yet another aspect, the disclosure relates to a spinal support construct that may comprise a primary spine stabilization structure which may include a pair of primary pedicle screws each configured for threaded insertion into a vertebra of the patient, with each of the primary pedicle screws including a threaded body portion and a head portion defining a cavity. The primary spine stabilization structure may further include a primary rod extending into the cavities of the primary pedicle screws. The construct may also comprise a secondary spine stabilization structure which may include a secondary pedicle screw configured for threaded insertion into a vertebra of the patient, with the secondary pedicle screws including a threaded body portion and a head portion defining a cavity. The secondary spine stabilization structure may include a secondary rod having a portion positioned in the cavity of the secondary pedicle screw and extending to the primary spine stabilization structure, and an interface structure linking the secondary rod to the primary spine stabilization structure.
[0007] There has thus been outlined, rather broadly, some of the more important elements of the disclosure in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional elements of the disclosure that will be described hereinafter and which will form the subject matter of the claims appended hereto.
[0008] In this respect, before explaining at least one embodiment or implementation in greater detail, it is to be understood that the scope of the disclosure is not limited in its application to the details of the construction and to the arrangements of the components, as well as the particulars of the steps, set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and implementations and is thus capable of being practiced and carried out in various ways. Also it is be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0009] As such, those skilled in the art will appreciated that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present disclosure. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present disclosure.
[0010] The advantages of the various embodiments of the present disclosure, along with various features of novelty that characterize the disclosure, are disclosed in the following descriptive matter and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The disclosure will be better understood and when consideration is given to the drawings and the detailed description which follows. Such description makes reference to the annexed drawings wherein:
[0012] FIG. 1 is a schematic side view of the new system utilizing the rod interface device according to the present disclosure.
[0013] FIG. 2 is a schematic sectional view of the rod interface device of the system, according to an illustrative embodiment, from the perspective of line 2 - 2 of FIG. 1 with the jaws shown in the release position.
[0014] FIG. 3 is a schematic sectional view of the rod interface device of the system, according to an illustrative embodiment, from the perspective of line 2 - 2 of FIG. 1 with the jaws shown in the gripping position.
[0015] FIG. 4 is a schematic sectional view of the rod interface device taken along a plane substantially perpendicular to plane of the sections shown in FIGS. 2 and 3 , according to an illustrative embodiment.
[0016] FIG. 5 is a schematic side view of an illustrative embodiment of the system utilizing a screw interface device.
[0017] FIG. 6 is a schematic side sectional view of the screw interface device, according to an illustrative embodiment, from a perspective taken along line 6 - 6 of FIG. 5 .
[0018] FIG. 7 is a schematic sectional view of the screw interface device taken along a plane substantially perpendicular to the plane of the sections show in FIG. 6 , according to an illustrative embodiment.
DETAILED DESCRIPTION
[0019] With reference now to the drawings, and in particular to FIGS. 1 through 7 thereof, a new system and method for lengthening an existing spinal support structure embodying the principles and concepts of the disclosed subject matter will be described.
[0020] Spinal surgeries, and especially spinal fusion surgeries, utilize a bone graft to fuse the adjacent vertebrae. Often metal screws are mounted on the vertebral body, and a rod or rods are secured to the screws, to hold the vertebrae in place while the spine fusion heals. The screws are mounted on the pedicle portion of the vertebra, which forms the small bony tube for the spinal cord, to grab into the bone of the vertebral body for a solid anchoring on the vertebra. After the screws are mounted, with one in each pedicle, the rod or rods are attached to connect all the screws together to create a relatively rigid metal frame that holds the vertebrae in position with respect to each other. A bone grafting material may then be placed around the back of the vertebrae to help heal and fuse the vertebrae together. Increasingly the surgery can be performed in a minimally invasive matter, so that the screws and rods may be placed using a series of small incisions rather than one long incision extending at least the length of the rod or rods.
[0021] After a spinal fusion surgery has been performed, the spinal discs adjacent to the fused discs may have increased pressure and may fail, requiring spinal fusions at additional levels of the spine in surgery generally referred to as revision spine surgery. Applicant has recognized that unlike the initial spinal fusion surgery, the revision surgery may not be able to be performed in a minimally invasive manner, such as by substituting a longer rod to reach the additional spinal vertebra levels. Applicant has further recognized that it would be advantageous to avoid revision surgery that utilizes the conventional practice of making a full-length incision to remove the existing rod, install pedicle screws on the additional vertebrae levels, and then install a new longer rod mounted to the existing and new screws.
[0022] In one aspect, the disclosure relates to a system 10 for adding or integrating one or more rods to an existing rod and pedicle screw installation, such as an installation from a previous spinal surgery. In some embodiments, connection of the additional rod is made to the rod previously implanted in the patient, and in some embodiments the connection of the additional rod is made to a pedicle screw of a previous surgery. The implantation and assembly of the elements of the system may be conducted in a minimally-invasive manner, generally without forming a large incision in the tissue of the patient and instead may be conducted through small incisions. Removal of the existing spine support structure including any rods and screws, is not typically needed for implementation of the system 10 .
[0023] In some embodiments, the system 10 may include an existing spine stabilization structure 12 that has previously been implanted in the patient and my be attached to the spine of the patient. The existing spine stabilization structure 12 may include a pair of pedicle screws 14 , 15 that are configured for threaded insertion into the vertebra 2 , 3 of the patient, with each of the pedicle screws being mounted on the pedicle of a vertebra of the patient. The particular configuration of the screw is not critical as long as the screw is suitable for the purpose. An illustrative suitable screw will be described.
[0024] Each of the pedicle screws 14 , 15 may include a head portion 16 which defines a cavity 18 . The cavity 18 may be defined or bounded by inner surface 20 which may have threads formed thereon for purposes that will become apparent. A channel 22 may be formed in the head portion 16 and may extend through the cavity 18 for receiving a portion of a rod therein. The channel 22 may extend along a transverse axis 24 that is oriented substantially transverse to a longitudinal axis of the pedicle screw. The screws 14 , 15 may also include a body portion 28 that is connected to the head portion either rigidly or in a manner permitting some relative movement therebetween. The body portion may be configured to be threaded into a hole formed in the vertebra, and at least a portion of the exterior surface 29 may be threaded. The body portion 28 may terminate in a tip 30 . The existing spine stabilization structure 12 may further include an existing rod 32 that extends between the pedicle screw 14 , 15 with a portion of each existing rod being lodged in the channel 22 of each of the head portions 16 of the respective pedicle screws.
[0025] The system may also include an interface structure 34 that is configured to link an additional rod to another rod, such as a rod that was placed in a previous surgery. The interface structure 34 may be placed in a minimally-invasive manner, although a minimal invasive installation is not required.
[0026] In some embodiments of the system, the interface structure 34 may comprise a rod interface device 36 that is configured to connect an additional rod 38 to an existing rod 32 . The rod interface device may include a frame 40 that has a bottom wall 42 and a perimeter wall 44 that extends upwardly from the bottom wall to partially define an interior 46 of the frame. The perimeter wall 44 may have an inward surface 48 with threads formed thereon. A pair of opposed grooves 49 may be formed in the perimeter walls to receive the additional rod therein. An opening 50 may be formed in the bottom wall 42 and the bottom wall may have a pair of cavities 52 , 53 that are positioned at opposite locations on the opening 50 in opposition to each other. The grooves 49 in the perimeter wall may form a pair of perimeter wall portions that are located on opposite sides of the frame, and in some of the most preferred embodiments the perimeter wall portions may be elongated to help guide the movement of the device elements, tools, as well as other things into the operative area (such as through an incision in the body of the patient). These elongate perimeter wall portions, which are illustratively shown in FIGS. 1 and 5 , may have a score line or line of reduced thickness and weakness formed across the portion that allows the perimeter wall portion to be severed or broken at the line, for example, when the device has been implanted. The relative length of the section beyond the line that may be removed may be one to ten or more times the length of the section that remains connected to the bottom wall. The position of the score line on the perimeter wall portions is preferably positioned at a distance from the bottom wall that minimizes the protrusion of the perimeter wall portion more than is necessary to accomplish the functionality of the interface structure. Illustratively, the position of the score line on the perimeter wall portion, and the height of the wall portion, may be sized to minimize the protrusion of the perimeter wall portions beyond, for example, the rod securing element 82 .
[0027] The rod interface device 36 may further include a pair of gripping jaws 54 , 55 that may be configured to releasably grip the existing rod 32 so that the interface device 36 may be attached to the rod 32 in a secure manner. The gripping jaws 54 , 55 may be movable with respect to each other between a release position (see FIG. 2 ) a gripping position (see FIG. 3 ). The gripping jaws 54 , 55 may be mounted to pivot with respect to each other, and may be mounted on the frame 40 in a pivotable manner.
[0028] The jaws 54 , 55 may have similar or identical configurations, but that is not critical. Each of the gripping jaws may include an inner surface 56 that faces an inner surface of the other jaw, with the inner surfaces being relatively closer together in the gripping position and relatively farther apart in the release position. One or both of the inner surfaces 56 of the jaws 54 , may have a recess 58 for receiving a portion of the existing rod 32 and a recess in one inner surface may be positioned in opposition to the recess of the other jaw when the jaws are in the gripping position. In some embodiments, the recess may be substantially semi-cylindrical in shape, although other shapes may be employed. The inner surface of the jaws may be generally planar about the recess. The jaws 54 , 55 may have an inboard end 60 positioned relatively closer to the frame 40 , an outboard end 61 positioned relatively farther from the frame. The jaws 54 , 55 may have an outer surface 62 that tapers smaller toward the outboard end and larger toward the inboard end such that a relatively smaller tip is created that facilitates insertion of the jaws and frame into an incision in the body, and the tapered shape of the outer surface of a jaw may have a semi-conical shape.
[0029] Each of the gripping jaws 54 , 55 may include closing tab 64 , 65 that may extend from the respective jaw at the inboard end and may extending in a direction substantially opposite from the outboard end of the jaw. A pair of pivot pins 66 , 67 may mount the gripping jaws on the frame 40 in a manner permitting pivot movement of the jaw with respect to the frame. The pivot pins have opposite ends that may be positioned in the cavities 52 , 53 of the frame, and each pivot pin may extend through one of the jaws and across the opening 50 of the frame.
[0030] The interface structure 34 may further include a jaw manipulation structure 70 that may be configured to move the jaws between the gripping position and the release position in a controllable manner. The manipulation structure 70 may comprise a jaw closer element 72 that may be configured to contact the jaws 54 , 55 and move the jaws toward the gripping position. The jaw closer element 72 may be mounted on the frame 40 and may be rotatable with respect to the frame, and in some embodiments a perimeter surface of the jaw closer element may have threads formed thereon to engage the threads on the inward surface 48 of the perimeter wall 44 of the frame. By the engagement of the threads, the jaw closer element may be moved closer to, and away from, the bottom wall 42 of the frame by rotating the closer element in one rotational direction or the other direction. The jaw closer element 72 may have a tool recess 73 formed thereon to receive a portion of a tool 4 to cause rotation of the closer element 72 by the surgeon.
[0031] The jaw closer element 72 has an abutment surface 74 that is positioned to be able to contact the closing tabs 64 , 65 of the jaws when the closer element is moved toward the bottom wall of the frame, such as by rotation on the threads engaging the perimeter wall of the frame. As the closer element 72 contacts the tabs 64 . 65 and the closer element 72 is moved closer toward the bottom wall the abutment surfaces presses against the tabs and moves the tabs toward the bottom wall and also outwardly relative to each other. The effect on the jaws is to pivot the jaws toward the gripping position, with the outboard ends 61 moved toward each other as well as the inner surfaces 56 and the recesses 58 of the jaws. The movement of the jaws toward the gripping position allows the recesses to close in upon a rod 32 that is located between the jaws, and may effectively trap the rod between the jaws and secure the frame to the rod.
[0032] The jaw manipulation structure 34 may also include a jaw spreader element 76 that may be configured to move the jaws toward the release position when in a first relationship (see FIG. 2 ) with the jaws and to permit the jaws to move toward the gripping position when in a second relationship (see FIG. 3 ) with the jaws. Three spreader element 76 may have a tapered shape, and in some embodiments may have a substantially conical shape that is inverted when the interface structure 34 is positioned above a rod for coupling.
[0033] The jaw spreader element 76 may be moveable with respect to, and between the jaws. The jaw spreader element may be rotatable with the jaw closer element 72 such that movement of the closer element 72 with respect of the frame also moves the spreader element with respect to the frame. The jaw manipulation structure 34 may further comprise a jaw connector element 78 that may connect the jaw spreader element 76 to the jaw closer element such that movement of the jaw closer element is transferred to the jaw spreader element. The transferred movement may include translational movement as well as rotational movement. The jaw connector element may extend between the jaws. In some embodiments, the jaw closer element, the jaw connector element and the jaw spreader element are formed of a single piece of material.
[0034] In a general sense, movement of the closer element toward the bottom wall 42 moves the spreader element away from the wall 42 and movement of the closer element away from the wall 42 moves the spreader element toward the wall 42 . Movement of the jaw spreader element toward the bottom wall causes contact of the outer surface of the spreader element with the inner surfaces 56 of the jaws and the tapered shape of the spreader element tends to push the inner surfaces away from each other and pivot the outboard ends of the jaws away from each other, opening the jaws toward the release position, as the tapered spreader element wedges between the jaws. Movement of the jaw spreader element away from the bottom wall 42 allows the inner surfaces of the jaws to move toward each other, especially in conjunction with the movement of the abutment surface 74 of the jaw closer element against the closing tabs 64 of the jaws. As the jaw closer element moves closer to the bottom wall, and the jaw spreader element moves away from the bottom wall, the jaws are moved toward the gripping position.
[0035] The rod interface device 36 may also include a rod seating element 80 for stabilizing the position of the additional rod 38 when positioned in the frame interior and passing through the channel 22 . The rod seating element 80 may be positioned in the interior of the frame, and may be positioned adjacent to the jaw closer element 72 of the jaw manipulation structure 70 with the rod 38 abutted against the device 36 . The rod seating element 80 may have a midsection of tapered thickness with an outer section of thicker thickness relative to the midsection to tend to center the rod 38 toward the center of the channel. A rod securing element 82 may be positioned in the interior of the frame, and may have an outer peripheral surface formed with threads to engage the threads on the inward surface 48 of the frame. The rod securing element may have a tool recess 84 for receiving a tool to rotate the rod securing element to tighten the abutment of the securing element 82 against the rod 38 as well as loosen the abutment if desired.
[0036] Methods of using the system 10 with the rod interface device 36 may include steps of locating a location on the existing rod where the additional rod is to be connected to the existing rod, forming an incision in the patient to access the location on the existing rod, and moving the rod interface device through the incision to the location in the existing rod. While moving the rod interface device yp the location, the jaws may preferably be in the gripping position such that the jaws present a relative tapered profile to the tissue on the sides of the incision. The jaws are placed in the gripping position by moving the jaw closer element 76 toward the bottom wall 42 by rotating the jaw closer element, which in turn presses the abutment surface 74 against the closing tabs 64 , 654 of the jaws. Once the rod interface device is positioned close the existing rod, the jaw may be moved toward the release position by rotating the jaw closer element on the threads in a manner that moves the closer element away from the bottom wall, which in turn moves the jaw spreader element toward the bottom wall, and wedges the spreader element 76 between the jaws and tends to rotate the jaws toward the release position. Once the outboard ends of the jaws are suitable spread, then the rod interface device may be advanced toward the existing rod 32 to move the rod 32 between the jaws and into the recesses 58 of the jaws. Once the rod 32 has sufficiently moved into position between the recess, the jaws closer element may be rotated in a direction that moves the closer element on the threads toward the bottom wall, bringing the abutment surfaces against the closing tabs, and moving the jaw spreader element away from the bottom wall and out of the wedged relationship with the jaws. The outboard ends of the jaws tend to move toward each other each other, trapping the existing rod in the recesses or, and between, the jaws.
[0037] The rod seating element 80 , if utilized, may be positioned adjacent to the jaw closer element, and a portion of the additional rod 38 may be positioned in the grooves 49 of the perimeter wall of the frame such that the rod portion passes through at least a portion of the interior of the frame. The additional rod may be inserted into the operative area through known minimally-invasive techniques. The rod securing element 82 may be threaded into the interior of the frame by rotating and brought into abutment with the rod with sufficient pressure to hold the rod against the rod seating element and/or jaw closer element.
[0038] In some embodiments of the system 10 , the interface structure 34 may comprise a screw interface device 90 that is configured to connect the additional rod 38 to an existing screw 14 . The screw interface device 34 may be configured to be connected to the head portion of a pedicle screw, and in particular a pedicle screw that includes a perimeter wall with threads formed on at least a portion of the inward surface of the perimeter wall. The screw interface device 90 may include a screw mount element 92 that is configured to be mounted on the head of the pedicle screw, such as the existing pedicle screw of a previous surgery with an existing rod 32 remaining in place. More specifically, the screw mount element may be mountable on the head portion 16 of the screw, such as by insertion of a portion of the mount element 92 into the cavity 18 and enging the threads formed on the inner surfaces 20 of the head portion.
[0039] The screw mount element 92 may include a first mount portion 94 that has a threaded outer surface 96 for engaging the threads of the inner surface of the head portion of the screw. The outer surface 96 of the first mount portion 94 may be substantially cylindrical with the threads thereon such that engagement between the respective threads causes the first mount portion to move into the cavity 18 of the head portion as the mount element or at least the first mount portion is rotated. The first mount portion 94 may be employed to press and secure the existing rod 32 into the cavity 19 and the channel 22 by contact with a lower surface 98 of the mount portion with the rod 32 . The screw mount element 92 may include a second mount portion 100 that extends from the first mount portion 94 , and may have a partially spherical surface.
[0040] The screw mount element may also include a rod mount element 102 that is mounted on the screw mount element 92 and may be mounted on the rod mount element in a manner permitting movement of the rod mount element in a manner permitting movement of the rod mount element with respect of the screw mount element, although this is not critical. The rod mount element 102 may define a cavity 104 that receives a portion of the second mount portion 100 of the screw mount element, and the internal surface defining the cavity may be at least partially spherical in shape to engage the surface of the second mount portion. The rod mount element 102 may also include a lower wall 106 within the cavity 104 formed therein and a side wall 108 extending upwardly form the lower wall. The lower and side walls may define a pocket 110 for receiving the additional rod therethrough, and the side walls may have a pair of opposed notches 112 through which the rod extends into and out of the pocket. A rod seating element may be located in the pocket 110 , and a rod securing element may also be positioned in the pocket to engage the threads and abut against the additional rod to hold the rod in the pocket
[0041] Methods of using the system 10 with the screw interface device 90 may include steps of locating a location of an existing screw 14 to which the additional rod is to be connected, forming an incision in the patient to access the location of the screw, and moving the screw interface device through the incision in the patient to the location adjacent to the screw, such as the head portion of the screw. An existing screw element may be removed from the head portion of the screw prior to insertion of the interface device 90 , but in some implementations that securing element may be left in place if sufficient room remains in the cavity for a section of the first mount portion 94 of the screw mount element 92 . A section of the first mount portion may be threaded into the cavity and may be rotated to a degree that the screw mount engages the existing rod if an existing rod has been removed. Once the screw mount element has been secured to the head portion of the screw, a rod seating element may be inserted into the pocket and then the additional rod may also be inserted into the pocket and then the additional rod may also be inserted into the pocket 110 and through at least one of the pair of opposed notches 112 of the rod mount element 102 . The additional rod may be inserted into the operative area through known minimally-invasive techniques. A rod securing element may be inserted into the pocket and engaged with the threads by rotation, with rotation continuing until the rod securing element places sufficient pressure against the rod to securely anchor it in place.
[0042] It should be appreciated that the foregoing description and appended claims that the terms substantially, mean “for the most part” or “being largely but not wholly or completely that which is specified” by the modified term.
[0043] It should also be appreciated from the foregoing description that, except when mutually exclusive, the features of the various embodiments described herein may be combined with features of other embodiments as desired while remaining within the intended scope of the disclosure.
[0044] Further, those skilled in the art will appreciate that the steps shown in the drawing figures may be altered in a variety of ways. For example, the order of the steps may be rearranged, substeps may be performed in parallel, shown steps may be omitted, or other steps may be included, etc.
[0045] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the disclosed embodiments and implementations, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art in light of the foregoing disclosure, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present disclosure.
[0046] Therefore, the foregoing is considered as illustrative only of the principles of the disclosure. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the disclosed subject matter to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the claims. | The present application discloses an implantable device for spinal treatment or stabilization. The device includes a spinal rod support and gripping jaws. The gripping jaws operate between an opened position and a closed position to grip and release a first spinal rod implanted into a patient. The spinal rod support includes a perimeter structure having an interior cavity and passage to connect a second spinal rod to the device to operably connect the first and second spinal rods through the implantable device to form a spinal stabilization structure. | 0 |
This is a continuation of application Ser. No. 969,128, filed Dec. 13, 1978, now abandoned.
BACKGROUND OF THE INVENTION
A. Field of the Invention
The present invention relates generally to valves for controlling the flow of fluid in a fluid system and particularly to an improved poppet stem guide for controlling the movement and location of a poppet stem in a check or relief valve.
B. Description of the Prior Art
Check valves or relief valves are well known devices for controlling the flow of fluid in a fluid system. One common characteristic of many prior art check valves is their relatively complex and thus expensive construction. Examples of typical prior art check valves are the devices disclosed in U.S. Pat. Nos. 2,594,641, 3,288,167, 3,334,659, and 3,473,561.
One component of these prior art check valves that adds substantial cost both in material and assembly is the poppet guide. One such guide is disclosed in U.S. Pat. No. 3,800,824. Poppet guides serve to guide and locate the poppet within the check valve while minimizing flow restriction. Typically, prior art guides are fabricated from material that is substantial in cost and expensive to assemble within the check valve and are often subject to jamming after short periods of use.
SUMMARY OF THE INVENTION
The present invention is directed to a new and improved poppet guide that is employed in a check valve, or the like. The check valve includes a one-piece body having an internal bore that is in communication with the fluid inlet and fluid outlet of the valve. A valve seat is defined within the bore and a poppet valve is positioned to engage the valve seat to provide one-way flow through the check valve.
The guide includes an annular cylindrical rim and a co-axial guide hub defined within the rim. Radial webs or spokes extend from the guide hub to the annular rim. There is at least one projection defined on the outer periphery of the rim that is diametrically opposed from the radial webs.
In one type of check valve, the projections provide an interference fit against the inner circumferential periphery of a machined portion of the bore once the poppet guide is positioned in the bore of the check valve. In a second type of check valve, ribs defined within a machine portion of the bore of the valve are straddled by the projections and the outer peripheral surface of the rim between the projections engages the ribs to provide a resistance or interference fit holding the guide within the finished valve bore.
The guide hub includes one or more lugs molded, or otherwise suitably formed, on its inner peripheral surface and the stem of the poppet valve is of a polygonal shape, such that the lugs engage at least one of the sides of the valve stem allowing axial movement while preventing rotation of the valve stem relative to the valve.
Valves having a guide in accordance with the present invention have many advantages. As compared to prior art valves, they are simple, and relatively inexpensive, both in terms of material cost and assembly. The guide is held against movement relative to the valve, and the stem is held against rotation relative to the guide, thereby minimizing wear and prolonging the life of the valve. Sufficient clearance is provided between the guide hub and the stem to minimize the possibility of particulate matter jamming therebetween. And, the guide itself provides for streamlined fluid flow therethrough.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cut-away perspective view of a first valve including a poppet guide constructed in accordance with the principles of the present invention;
FIG. 2 is a view taken along line 2--2 of FIG. 1;
FIG. 3 is a second valve including a poppet guide constructed in accordance with the principles of the present invention; and
FIG. 4 is an enlarged end view of an embodiment of the poppet guide of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment in accordance with the present invention, and with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated and described.
Having reference to the drawing and initially to FIGS. 1, 2, and 4, there is illustrated a new and improved check valve and poppet guide constructed in accordance with the principles of the present invention. The check valve is designated as a whole by the reference numeral 10 and is used to control the flow of fluid in a fluid system, and specifically, to allow unidirectional flow in the fluid system. The check valve 10 includes a novel poppet guide that functions to guide a poppet stem within the check valve 10.
The check valve 10 includes a body 12 having an inlet 14 and an outlet 16. The inlet 14 and the outlet 16 are threaded to allow the valve 10 to be easily coupled to a pipeline or similar fluid system. Defined between the inlet 14 and the outlet 16 and within the body 12 is an elongated bore 18 through which fluid flows when the valve 10 is open. The body 12 includes an annular valve seat 20 defined on the inner peripheral surface of the bore 18. The check valve 10 further includes a poppet 22 for forming a fluid-tight sealing engagement with the valve seat 20. Poppet 22 is preferably formed of an elastomeric material. When the poppet 22 is positioned in sealed engagement with the valve seat 20, back flow of fluid through the check valve is prevented. When the poppet 22 is in an open position spaced from and out of sealing engagement with the valve seat 20, flow of fluid through the check valve 10 from the inlet 14 through the outlet 16 is permitted.
A poppet stem generally designated by reference numeral 24 extends longitudinally through the bore 18 and is secured to the poppet 22. The poppet stem 24 is of a polygonal configuration in cross section, and in the embodiment illustrated, is of a square cross-sectional configuration having flat sides 25. The poppet stem 24 is utilized to control the movement of the poppet 22 with respect to the valve seat 20. The poppet stem 24 may be connected to the poppet 22 by any suitable means, such as, by having an upper flattened portion 26a embrace a metal stiffening element 26, and molding the poppet around the end of the poppet stem including the stiffening element 26.
The poppet stem 24 includes a threaded end portion 28 for receiving a threaded lock nut 30. The lock nut 30 serves as a lower limit, or shoulder, for one end of a compression spring 32, and the opposite end of spring 32 bears against a poppet guide 34, to be hereafter described in detail. The compression spring 32 provides the necessary bias to maintain the poppet 22 in sealing engagement with the valve seat 20. When force exerted by the pressure of the fluid in the check valve 10 against the undersurface of the poppet 22 exceeds the opposing bias force provided by the compression spring 32, the poppet 22 disengages from the valve seat 20 to permit fluid to flow through the check valve 10, and such fluid flow will continue so long as the fluid pressure at the inlet side of the check valve exceeds the bias of spring 32. The bias force imparted by the compression spring 32 may be adjusted by varying the longitudinal position of the threaded nut 30 on the threaded end portion 28 of the valve stem 24. Thus, the operation of the check valve 10 can be easily adjusted to permit fluid flow at any desired fluid pressure.
In accordance with an important feature of the present invention, poppet guide 34 provides for both positioning the poppet stem 24 within the bore 18 of the check valve 10, and for controlling the movement of the stem 24 along a longitudinal axis coincident with the central longitudinal axis of the bore 18. Guide 34 is formed of a flexible smooth surface bearing material, such as, DELRIN. In addition, poppet guide 34 prevents rotation of the poppet 22 and the stem 24 relative to the body 12 of the check valve 10. By controlling the position and movement of the poppet stem 24, the poppet guide 34 controls the position and movement of the poppet 22 to cause the poppet 22 to engage the valve seat 20 in a proper alignment. And, by preventing the valve stem from rotating relative to the valve body, wear resulting from excessive movement is minimized, thus prolonging the useful life of the valve.
In accordance with an important advantage of the present invention, and as can be best seen from FIG. 4, the poppet guide 34 includes a thin resilient rim 36 of a tapered cross section to define a fluid flow passage that is streamlined, i.e., progressively increasing in size, to reduce the flow resistance of the rim 36. The poppet guide 34 also includes a cylindrical hub 38 that is coaxial with the rim 36, and hub 38 includes on its inner peripheral surface one or more lugs 40 that extend along a portion of the entire length of the hub 38.
The hub 38 and rim 36 are joined and spaced from each other by radially extending webs or spokes 42 that are of a cross-sectional configuration substantially similar to that of the rim 36 so as to further streamline the fluid flow passages and reduce resistance to flow through the guide 34 and along the bore 18. In a most preferred embodiment, both surfaces of rim 36 and webs 42 are uniformly tapered.
The stem guide 34 in its entirety is fabricated, by molding, or the like, from material that allows some deformation of the rim 36 during assembly of the guide 34 into the check valve 10. The guide 34 is of a diameter relative to the diameter of a machined intermediate portion of the bore 18 such that once the guide 34 is positioned within the bore 18, it remains slightly compressed, thereby producing a force that assists the interference fit of the guide 34 in the bore 18 in holding the guide 34 within the machined portion of the bore 18.
To prevent the guide from rotating within the check valve 10, the pairs of circumferentially spaced, axially extending lugs or projections 44 defined on the outer peripheral surface of the rim 36. In the preferred embodiment illustrated, the lugs 44 are located approximately at a point on the rim 36 diametrically opposed to the point of intersection of the webs 42 with the rim 36. This location of the lugs 44 allows maximum deformation of the rim 36 if force is applied at or near the lugs 44, as when the guide is inserted in the valve body.
To maintain the valve guide 34 within the check valve 10, the valve 10 includes legs or ribs 46 defined on the inner peripheral surface of the bore 18. To assemble the poppet guide 34 in the check valve 10, the poppet guide 34 is positioned within the inlet 14 of the check valve 10 by moving the guide 34 longitudinally within the bore 18 so that the outer periphery of rim 36 between the projections 44 engages the apex of the legs 46. The apex of the legs 46 defines a cylindrical area of a diameter slightly less than the diameter of the outer periphery of the rim 36. Accordingly, as the poppet guide 34 is moved further into the machined intermediate portion of bore 18, ribs 46 exert an inward compressive force, and a slight inward deformation of the rim 36 at the interface of the rim 36 and the legs 46 occurs. Once the poppet guide 34 is fully positioned within the machined portion of bore 18, the downstream end of the valve guide 34 abuts against a shoulder 48 machined within bore 18.
Once assembled, there is a significant force due to the deformation of the rim 36 holding the valve guide 34 in position. This force, together with the confining action of ribs 44, is sufficient to prevent movement of the valve guide 34 by the swirling motion or influence of fluid flowing through the check valve 10. Consequently, wear due to rotation of the valve guide 34, within the machined portion of bore 18, as is prevalent in prior art valve guides, is prevented.
To complete the assembly of the check valve 10, the poppet stem 24 is inserted axially into the hub 38 such that the lugs 40 face the sides 25 of the poppet stem 24, and spring 32 is positioned around the valve stem 24, with one end seated within a set of grooves 50 defined in the webs 42 of the valve guide 34. The other end of the spring 32 seats against the lock nut 30 once it is threaded on the end 28 of the stem 24. The inner diameter of the hub 38 is slightly larger than the transverse dimension of the valve stem 24, such that the valve stem 24 may move freely in a longitudinal direction within the intermediate portion of bore 18 and the hub 38 without interference. This allows free movement of the poppet 22 under the influence of fluid pressure and the spring 32 and reduces the likelihood of jamming of the stem 24 within the hub 38 due to sand, or other particulate matter that may be entrained in the fluid. Rotation of the stem 24, however, is prevented due to the engagement of the lugs 40 with the sides 25 of the stem 24.
The poppet guide 34 may also be used in a second type of check valve, such as the check valve 110 illustrated in FIG. 3. The check valve 110 is of the type that may be used at the inlet of a fluid system and includes a screen 111 that is secured to the inlet 114 of the check valve 110 to filter or screen particles and prevent their entry into the fluid system.
The check valve 110 includes a body 112 having an inlet 114 at one end and an outlet 116 at the other end. The inlet 114 is externally threaded to allow the attachment of the screen 111. The outlet 116 is internally threaded to allow coupling to the fluid system, such as a pipe line.
The check valve 110 also includes an internal bore 118 and a valve seat 120 substantially similar to the corresponding components of the check valve 10. The check valve 110 further includes a poppet 122 for forming a fluid-tight sealing engagement with the seat 120. In a sealed engagement, the poppet 122 and the valve seat 120 prevent flow of fluid from the outlet 116 to the inlet 114 of the check valve 110. In a non-sealing engagement, or when disengaged, the poppet 122 and the valve seat 120 permit the flow of fluid through the check valve 110.
A poppet stem 124 is securely attached to the poppet 122 and extends longitudinally through the bore 118 of the check valve 110 and into screen 111. In a manner substantially similar to the poppet stem 24. in the check valve 10, the poppet stem 124 is utilized to control the movement of the poppet 122 with respect to the valve seat 120. The poppet stem 124 is connected to the poppet 122 in any suitable manner, such as by molding the poppet about an enlarged stiffener 126 at the end of the stem.
The poppet stem 124 is polygonal in configuration and includes sides 125 that, in a preferred embodiment, may be of a configuration substantially similar to the valve stem 24. The poppet stem 124 also includes a threaded end 128 to which a lock nut 130 may be threaded to serve as a shoulder for the spring 132 once the spring 132 is mounted around the stem 124.
The check valve 110 differs from the check valve 10 in that the check valve 110 does not include cast legs or ribs 46, but rather the inlet 114 is of a diameter slightly smaller than the diameter of the poppet guide 34. Consequently, to assemble the valve guide 34 in the check valve 110, the valve guide 34 is press-fitted, or pushed, into the inlet 114 against the shoulder in a manner such that the lugs 44 on the outer peripheral surface of the rim 36 engage the inner peripheral surface of the inlet 114 slightly deforming the rim 36. This slight deformation provides a holding force imparted to the inner peripheral surface of the inlet 114 resulting in a securement of the poppet guide 34 within the inlet 114 with sufficient force to prevent movement of the poppet guide 34 as a result of the swirling motion of fluid flowing through the check valve 110.
To complete the assembly of the check valve 110, poppet stem is inserted through the poppet with the lugs 40 engaging surface 125, and spring 132 is positioned so that one end of the spring 132 engages the slots 50 defined on the webs 42. The lock nut 130 may then be threaded on the end 128 to serve as a shoulder for the other end of the spring 132. The screen 111 may then be threaded on the external threads defined on the inlet 114.
During operation of the check valve 110 the poppet stem 124 may slide longitudinally relative to the hub 38 and in a direction toward the outlet 116. The lugs 40, prevent rotation of the stem 124 within the bore 118.
In view of the above teachings, it may be understood that the poppet guide 34 due to its flexible material and ease of manufacture is easily assembled within several different types of check valves, such as the check valves 10 and 110, and is less subject to wear since it cannot be rotated within the check valve due to the influence of the swirling motion of fluid. Many modifications and variations of the present invention are possible in light of the above teachings. Thus, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise as specifically described. | A guide for a poppet in a check valve includes an annular, cylindrical rim and a guide hub concentric therewith. At least one web extends radially from the guide hub to the rim. The outer periphery of the rim includes at least one projection defined at a position angularly spaced from the web. The projection is engaged by the inner periphery of the check valve such that the guide is held within the check valve, with a stem on the poppet extending through the guide hub. The guide hub includes at least one lug to engage the stem to prevent rotation of the stem relative to the check valve. The guide is formed of a smooth bearing material, and the rim thereof is capable of flexing, in the area where the projections are provided. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for modulating acceleration in the driving system of an automotive vehicle such as an automobile or a tractor provided with a hydraulic transmission.
Generally, a driving system for an automtive vehicle such as a tractor provided with a hydraulic transmission comprises an engine as a prime mover, a hydraulic pump driven by the engine to produce a hydraulic pressure, and a hydraulic motor connected through a hydraulic circuit to the pump so that the motor is driven by the output pressure of the pump to produce a motive force for driving the wheels of the vehicle. Either the pump or the motor or both are of a variable displacement type, so that the transmission ratio may be changed by changing the displacement of either or both of the pump and the motor.
In this system, the output of the engine is controlled by an accelerator provided with a pedal or the like in such a manner that the amount of operation applied to the accelerator pedal is transmitted through a displacement transmitting element such as a wire to the throttle valve of a carburetor for the engine.
Normally, the system of the above type is used in the range in which the output pressure of the hydraulic pump remains lower than the relief pressure of the hydraulic circuit including the pump and the motor. Under the normal condition, the absorption torque is the product of the output pressure of the pump and the displacement thereof.
In a system in which the outupt of the engine can be freely controlled by stepping on the accelerator pedal, it often happens that the output of the engine is increased to such an unnecessarily high level that the pressure in the hydraulic circuit reaches the relief pressure, whereupon the excess hydraulic operating fluid is discharged out of the circuit through a relief valve, with resulting waste of energy and abnormal rise of the temperature of the hydraulic operating fluid. This is a great disadvantage.
The object of the invention is to provide an apparatus for modulating acceleration in the driving system of an automotive vehicle, which completely eliminates the above-mentioned and other disadvantages of the conventional systems.
The invention will be described with reference to the accompanying drawings.
DESCRIPTION OF THE DRAWING
FIG. 1 schematically shows a driving system in which the acceleration modulator of the invention is incorporated;
FIG. 2 is a top plan view of the acceleration modulator in the system of FIG. 1;
FIG. 3 is a vertical section of the modulator shown in FIG. 2;
FIG. 4 is a transverse section taken along line IV--IV in FIG. 3;
FIG. 5 is a transverse section taken along line V--V in FIG. 3; and
FIG. 6 is a block diagram of the device for taking out the pilot pressure used in the system of FIG. 1.
SUMMARY OF THE INVENTION
The acceleration modulator of the invention is incorporated into a hydraulic driving system which comprises a prime mover the output of which varies with the amount of operation applied to the terminal for controlling energy supply to the prime mover, a hydraulic pump driven by the prime mover, a hydraulic motor for driving the wheels of a vehicle, and a hydraulic circuit for connecting the pump and the motor to operate the motor with the output pressure of the pump thereby to drive the vehicle wheels.
Briefly stated, the acceleration regulator of the invention comprises: an element for transmitting displacement comprising a first portion and a second portion; a differential mechanism having a first input terminal connected to the first portion of the element, a second input terminal, and an output terminal connected to the second portion of the elemnet, and being so arranged that the amount of operation applied through the first portion of the element to the first input terminal is modulated differentially by the the position of the second input terminal so that the modulated amount of operation is taken out at the output terminal; and a fixing mechanism for variably fixing the position of the second input terminal of the differential mechanism, the fixing mechanism being so arranged that when the hydraulic pressure in the hydraulic circuit of the driving system rises to a preset level slightly lower than the relief pressure of the circuit, the second input terminal of the differential mechanism is moved to a position where the amount of output available at the output terminal of the differential mechanism decreases.
So long as the hydraulic pressure in the hydraulic circuit remains below the preset level adjacent to the relief pressure of the hydraulic circuit, the fixing mechanism holds the second input terminal of the differential mechanism at a fixed position. Under the condition, the amount of operation applied to the first portion of the displacement transmitting element and transmitted to the first input terminal of the differential mechanism is not changed but taken out at the output terminal of the differential mechanism so as to be transmitted to the control terminal of energy supply to the prime mover. In this case the output of the prime mover can be controlled in substantially the same manner as if there were no differential mechanism interposed between the first and second portions of the displacement transmitting element.
When an excessive amount of operation has been applied to the first portion of the displacement transmitting element so that the output of the prime mover increases thereby to cause the system pressure in the hydraulic circuit to exceed the preset level slightly lower than the relief pressure of the circuit, the fixing mechanism operates in response to the increased system pressure to change the fixed position of the second input terminal of the differential mechanism so as to reduce the amount of displacement to be taken out at the output terminal of the differential mechanism. As a result, as the excessive amount of operation applied to the first portion of the displacement transmitting element is delivered to the control terminal of energy supply to the prime mover, the amount is reduced to such a relatively low level as to prevent unnecessary increase of the output of the prime mover.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is schematically shown a driving system for an automotive vehicle, into which the acceleration modulator of the invention is incorporated as shown as a mere block 1. The driving system can be employed in a tractor, for example, and comprises an engine 2 as a prime mover, a hydraulic pump 3 driven by the output of the engine 2, a hydraulic motor 5 driven by the output hydraulic pressure of the pump 3, and a hydraulic circuit 4 connecting the pump and the motor. The motor 5 produces an output to drive the wheels of a vehicle shown as a mere block 10.
The pump 3 and the motor 5 are of a variable displacement type, so that the transmission ratios of the driving system can be varied continuously by changing the displacement of either or both of the pump and the motor. The hydraulic circuit 4 is provided with a relief valve 6 to define the upper limit of the system pressure thereby to prevent destruction of the circuit 4. The output of the engine 2 is controlled by the amount of operation on an accelerator pedal 7 transmitted through an element such as a wire 8 for transmitting the displacement of the pedal 7 to a fuel control terminal 9 of the engine 2 such as a throttle valve in a carburetor, not shown, for the engine.
In accordance with the invention, the wire 8 comprises two portions, that is, the forward portion 8a connected at one end thereof to the accelerator pedal 7 and the rear portion 8b connected at one end thereof to an operating rod 9a for controlling the throttle valve 9.
The acceleration modulator 1 of the present invention is provided between the other end of the forward wire portion 8a and the other end of the rear wire portion 8b. One form of the modulator 1 is shown in detail in FIGS. 2 through 5, comprising a differential gear mechanism 11 having a first and a second input terminal and an output terminal and so designed as to subtract the amount of operation applied to the second input terminal from the amount of operation applied to the first input terminal and produce an amount of operation corresponding to the result of subtraction at the output terminal, and a mechanism 12 for variably fixing the position of the second input terminal of the differential gear mechanism 11.
The differential gear mechanism 11 is enclosed in a casing 13, which supports the forward portion 8a of the wire 8 by a first lateral wall 13a thereof and the rear portion 8b of the wire by a second lateral wall 13b thereof extending at right angles with the first lateral wall 13a. In particular, the forward and rear wire portions 8a and 8b pass through bearing sleeves 14 1 and 14 2 , respectively, to be slidably supported thereby. The sleeves 14 1 and 14 2 are mounted on the lateral side walls 13a and 13b of the casing 13 by means of retainers 15 1 and 15 2 , respectively.
The forward wire portion 8a has its rear end 8A engaged with a recess 16a formed on the periphery of an input pulley 16 constituting the first input terminal of the differential gear mechanism 11. The rear wire portion 8b has its forward end 8B engaged with a recess 17a formed on the periphery of an output pulley 17 constituting the output terminal of the differential gear mechanism 11. The wire portions 8a and 8b run partially about the pulleys 16 and 17, respectively.
In the illustrated embodiment, the differential gear 11 is of the planetary type comprising a ring gear 18, a sun gear 19 secured to a shaft 19a and arranged within the ring gear 18 coaxially therewith, a gear retainer 21 arranged rotatably and coaxially with both the sun gear 19 and the ring gear 18, and a plurality, say, three planetary gears 22 rotatably supported on the gear retainer 21 by means of a pin 21a and engaged with both the ring gear 18 and the sun gear 19. The previously mentioned input pulley 16 is mounted on the ring gear 18 for simultaneous rotation therewith, and the previously mentioned output pulley 17 is mounted on the shaft 19a for simultaneous rotation therewith.
The gear retainer 21 has its under side fixed to a hollow cylindrical input shaft 23, which constitutes the second input terminal of the differential gear mechanism 11, for simultaneous rotation therewith. The input shaft 23 is rotatably supported by a pair of radial bearings 24 mounted in a boss 13c formed inside the casing 13. The ring gear 18 is mounted by a bearing 25 on the gear retainer 21 fixed to the upper end of the input shaft 23. The support shaft 19a of the sun gear 19 is rotatably supported on the input shaft 23 and the gear retainer 21 by means of bearings 26 and 27. The previously mentioned fixing mechanism 12 engages the input shaft 23 so as to fix the shaft at a desired angular position, which can be changed as will be described presently.
As shown in FIG. 5, the fixing mechanism 12 comprises a cylinder 31 formed in the casing 13 in association with the boss 13c, and a piston 32 slidably disposed in the chamber of the cylinder 31 so as to be operated by the pilot pressure taken out of the hydraulic pressure circuit 4 as will be described presently. The piston 32 is formed on the exterior surface thereof with a rack 33 extending axially of the piston and engaging a pinion gear 34 formed on the exterior circumferential surface of the input shaft 23.
In further detail, the cylinder 31 extends perpendicularly to the input shaft 23 and is provided at the opposite ends with a pair of caps 35 and 36 and a plug 35a liquid-tightly closing the cylinder chamber as shown in FIG. 5. The piston 32 is a hollow cylindrical member open at one end and closed at the other, with a compression coil spring 37 enclosed therein to normally urge the piston 31 against the inner face of the cylinder plug 35a. In the cylinder plug 35a there is formed a passage 38 connected to a device 41 for taking out a pilot pressure so that the pilot pressure taken out of the hydraulic circuit 4 is introduced through the passage 38 into a pilot pressure chamber 39 formed in the inner end face of the plug 35a defined by the closed end of the piston 32.
As schematically shown in FIG. 6, the device 41 for taking out a pilot pressure has an inlet port 42 through which the system pressure in the hydraulic circuit 4 the upper limit of which is defined by the previously mentioned relief valve 6 is introduced into the device 41, an outlet port 44 through which the pressure is discharged into a reservoir tank 43 shown in FIG. 1, a series combination of a first relief valve 45 and a restrictor 46 connected between the inlet and outlet ports 42 and 44, a pilot pressure port 47 connected between the first relief valve 45 and the restrictor 46 for a pilot pressure to be taken out therefrom, and a second relief valve 48 connected in parallel with the restrictor 46 to regulate the pilot pressure to be taken out.
The operating pressure of the first relief valve 45 is set to a level a little lower than that of the relief valve 6 in the hydraulic circuit 4. The pilot pressure port 47 is connected to the passage 38 in the cylinder plug 35a.
A sensor 51 detects the opening of the throttle valve 9, that is, converts the rotational angle of the support shaft 19a of the sun gear 19 in the previously mentioned differential mechanism 11 to a corresponding electrical signal, which is used for controlling the HST or HMT 2.
The system of the invention operates in the following manner.
So long as the system pressure in the hydraulic circuit 4 remains below the preset pressure level of the device 41 a little lower than the preset pressure of the relief valve 6, no pilot pressure will be supplied from the device 41 to the fixing mechanism 12, so that the spring 37 keeps the piston 32 abutting on the inner face of the cylinder plug 35a and consequently the input shaft 23 of the differential mechanism 11 at a predetermined angular position and the planetary gears 22 at predetermined waiting positions. Under the condition, the amount of displacement of the accelerator pedal 7 is transmitted to the input pulley 16 and thence through the ring gear 18, the planetary gears 22, the sun gear 19 and the support shaft 19a thereof successively to the output pulley 17 fixed to the upper end of the shaft 19a, so that the pulley 17 is rotated in the direction opposite to that of rotation of the input pulley 16 so as to pull the rear portion 8b of the accelerator wire 8 thereby to control the opening of the throttle valve 9 in accordance with the amount of operation on the accelerator pedal 7.
If the accelerator pedal 7 has been operated excessively so that the resulting increase in the output of the engine 2 causes the system pressure in the hydraulic circuit 4 to exceed the pressure preset level of the device 41 a little lower than the relief pressure of the relief valve 6 in the circuit 4, the first relief valve 45 in the device 41 is opened to introduce into the pressure chamber 39 of the fixing mechanism 12 a pilot pressure the upper level of which is defined by the opening pressure of the second relief valve 48. The pilot pressure introduced into the chamber 39 urges the piston 32 away from the cylinder plug 35a against the force of the spring 37, thereby to cause the input shaft 23 of the differential mechanism 11 engaged by the rack 33 on the piston 32 to rotate about the axis of the input shaft 23 for an angle corresponding to the pilot pressure, whereupon the positions of the planetary gears 22 on the gear retainer 21 change thereby to reduce the output angular displacement of the sun gear 19. This means that the amount of angular displacement of the input shaft 23 of the differential mechanism 11 has been subtracted from the amount of operation on the accelerator pedal 7 transmitted to the input pulley 16, and the resulting reduced amount of displacement is taken out from the output pulley 17 so as to control the opening of the throttle valve 9.
With the apparatus of the invention as described above in detail, even when the accelerator pedal 7 has been excessively operated by mistake, the output of the engine 2 is automatically restricted to prevent the system pressure from reaching the relief pressure level thereby to prevent a large amount of working fluid from being returned to the tank 43 through the relief valve 6, with resulting marked reduction of energy loss and effective prevention of abnormal rise of the temperature of the working fluid.
Since the displacement of the forward portion 8a of the wire 8 is transmitted through a gear type differential mechanism, that is, the differential mechanism 11 to the wire rear portion 8b, there is scarcely any error, delay or loss in transmission of movement, so that the operator can control the throttle valve 9 as effectively as if there were no acceleration modulator and without deterioration of the feeling of operating the throttle valve.
Advantageously the throttle position sensor 51 is secured to the lower portion of the shaft 19a which projects outside the casing 13 as in the illustrated embodiment of the invention, so that the sensor 51 is scarcely affected by the vibration of the engine.
A preferred embodiment of the invention having been described above in detail, the invention is not limited to the illustrated embodiment, but there may be many modifications. For example, it is possible to use other prime movers than the engine to dirve the hydraulic pump. The differential gear mechanism and the element for transmitting displacement are not limited to the illustrated forms.
The acceleration modulator of the invention can be easily incorporated into a driving system and prevent loss of energy and abnormal temperature rise of the working fluid which would otherwise be caused by excessive operation of acceleration of the driving system, and this is possible without damaging the feeling of operation of acceleration. Since the element for transmitting displacement comprises a wire, it enables easy connection to the differential gear and proper and reliable control of acceleration. | An acceleration regulator in the driving system of an automotive vehicle comprising an element for transmitting displacement comprising a first portion and a second portion; a differential mechanism having a first input terminal connected to the first portion of the element, a second input terminal, an an output terminal connected to the second portion of the element, and being so arranged that the amount of operation applied through the first portion of the element to the first input terminal is modulated differentially by the piston of the second input terminal so that the modulated amount of operation is taken out at the output terminal; and a fixing mechanism for variably fixing the position of the second input terminal of the differential mechanism, the fixing mechanism being so arranged that when the hydraulic pressure in the hydraulic circuit of the driving system rises to a preset level slightly lower than the relief pressure of the circuit, the second input terminal of the differential mechanism is moved to a position where the amount of output available at the output terminal of the differential mechanism decreases. | 5 |
This application claims priority of PCT International Application No. PCT/FR2009/050032 filed on Jan. 9, 2009. The contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The invention concerns a peristaltic pump, and in particular a peristaltic pump with a tube compressed by at least two sets of pressing elements.
Such pumps are known for the pumping of liquid, viscous and/or granular products such as concrete, for instance.
BACKGROUND
These pumps comprise two sets of rollers, radial and opposite with respect to the rotor supporting and rotating these sets of rollers. In each set of rollers, two rollers are linked and are separated from each other by a width such that the two walls of the tube are in contact and sufficiently compressed to ensure the tube's tightness during pumping.
Peristaltic pumps use an elastic elastomer tube that is relatively expensive, therefore it is important to ensure that this has a maximum useful life.
FIGS. 1 to 3 show such a peristaltic pump 1 according to the prior state of the art. This pump comprises a rotor 2 fixed on a drive shaft 3 . Fixed on this rotor 2 are two symmetrically opposed sets 4 , 5 of two rollers 6 , 7 rotationally mobile around their longitudinal axis 8 .
The two rollers 6 , 7 of each set 4 , 5 are positioned on either side of the tube 9 of the pump 1 and separated by a width e substantially equal to or less than the double width of walls 10 , 11 of the tube 9 , so as to ensure tightness in line with the compression of the tube 9 .
When the sets 4 , 5 of rollers move from the inlet 12 of the pump 1 towards its outlet 13 , by the rotation of the rotor, the compressed portion of tube 9 reverts to its original cylindrical shape after the passage of these sets of rollers.
Through the movement, or rotation, of the sets 4 , 5 of rollers, the product contained in the tube 9 is drawn in at the inlet 12 of pump 1 and ejected at the outlet 13 . The continuous rotation of rotor 2 consequently ensures a pumped flow of the product drawn in at the inlet 12 and then ejected at the outlet 13 .
The pumped flow is naturally proportional to the rotational speed of the rotor 2 and to the internal cross-section of the tube 9 . The rotation of the drive shaft 3 of rotor 2 of pump 1 is carried out by a motor, not shown.
The rollers 6 , 7 of each set 4 , 5 are cylindrical and radial cylindrical rollers 14 and axial cylindrical rollers 15 fixed on the rotor 2 guide the tube 9 and keep it in a centered position on the rotor 2 .
However, this pump 1 presents a number of drawbacks.
Firstly, it is noted that the axial cylindrical rollers 15 tend to embed themselves laterally at 16 in tube 9 under the latter's tension, since these rollers 15 only bear against one point. As a result, they deform the cylindricity of this tube 9 and reduce its suction capacity.
In addition, a cumbersome retention frame 17 is required to avoid having the tube 9 break away outwards.
In effect, it can be seen that, when these sets 4 , 5 of rollers rotate, a traction force is applied on the part of the tube 9 located upstream of these sets 4 , 5 , which therefore tends to be elongated under this force, thus causing buckling of the part of the tube 9 located downstream of these sets 4 , 5 , which must therefore be held by this external frame 17 .
In addition, the compression of the tube 9 by cylindrical rollers 6 , 7 produces a variable linear speed V 1 , V 2 , V 3 over their line of contact with the wall of tube 9 , thus creating sliding between this latter and the rollers as a result causing wearing of the external wall of the tube and also heating of the latter that is harmful to the life of the tube 9 .
Also, when the sets 4 , 5 of cylindrical rollers arrive in front of the tube 9 to compress it during the rotation of the rotor, the sharp edge 18 located at the end of each roller 6 , 7 strikes the external wall of the tube 9 and damages it, as a result also reducing the life of the tube 9 .
Additionally, when the pump 1 is not utilized, it can remain stopped for a variable length of time, from a few hours to several months. The tube 9 therefore remains compressed by at least one of the two sets 4 , 5 of rollers throughout the whole period during which pump 1 is not used. This can therefore lead to a permanent deformation of the elastomer of the tube 9 , reducing the suction capacity of this tube 9 very substantially as a result.
It can even result in a decrease in the tube's suction capacity such that pump 1 is no longer able to pump and move any product.
Moreover, the force for compressing the tube 9 by the rollers 6 , 7 spaced by width e must be the force required to ensure tightness during the pumping of the product at the maximum pressure that may be used. Because of this, the elastomer of the tube 9 is always subjected to a maximum deformation, not necessary when the pumping pressure is less.
Lastly, during the rotation of rotor 2 , when one of the sets 4 , 5 of rollers leaves contact with the tube 9 near the outlet 13 of pump 1 , the two rollers 6 , 7 are no longer driven by their friction on tube 9 and they therefore stop turning. Also when, after a certain rotation of rotor 2 , these rollers 6 , 7 arrive at the inlet 12 of pump 1 , they come into contact with the external wall of tube 9 with a zero rotational speed and therefore abruptly start rotating. This results in damage to the external wall of tube 9 in line with the two impacts caused by the two rollers 6 , 7 , thus reducing the life of said tube 9 .
SUMMARY OF THE INVENTION
The objective of this invention is therefore to propose a peristaltic pump, simple in its design and method of operation, allowing the drawbacks of pumps according to the state of the art to be eliminated.
To this end, the invention concerns a peristaltic pump comprising at least one elastically flattenable tube and at least two assemblies of two pressing elements placed opposite each other, each of said assemblies being intended to compress the tube at a different point of the pump.
According to the invention, the two pressing elements of a single assembly being placed on either side of the tube, at least one of the pressing elements of said single assembly is mobile such that the distance separating the pressing elements of this single assembly is adjustable, wherever said point of the pump is where said assembly of pressing elements is intended to compress said tube, to allow the pressing elements to be placed in a rest position, in which the tube is not compressed by these pressing elements, or in a position compressing said tube.
In different particular embodiments of this peristaltic pump, each having its specific advantages and capable of numerous possible technical combinations:
at least the pressing elements placed on a same first side of this tube are controlled by at least one actuator able to move these pressing elements between a rest position, where the pressing elements are set back from the pressing elements placed on the other side of the tube without pressing the tube, and a position referred to as the tube compression position, this or these actuators automatically move the pressing elements towards the tube compression position when the peristaltic pump or pumping is started, and conversely towards the rest position when the peristaltic pump or pumping is stopped so as to release said tube,
In a particular design version of the peristaltic pump, it is equipped with a hydraulic system that powers the rotor's drive motor.
A bypass of this hydraulic system by a specific hydraulic distributor enables control of the actuator or actuators made up of one or more hydraulic jacks.
When the peristaltic pump, and therefore the hydraulic system, is stopped the jack or jacks are no longer pressurized and the tube is released.
When the peristaltic pump is started, the hydraulic system is pressurized and the specific distributor operates the jack or jacks that compress the tube.
In an alternative embodiment, the automatic movement of the actuator or actuators only occurs when pumping is started, i.e. when the operator decides to actually pump the material by activating a means of control that pressurizes the hydraulic system simultaneously operating the rotor's drive motor and the actuator or actuators, as described above.
In this way damage to the tube when the pump is not working is avoided.
at least one of the pressing elements placed on a same side of the tube is mobile with respect to other pressing elements placed on the same side of the tube,
Said at least one pressing element mobile with respect to the others allows, for example, a temporary movement of this pressing element in order to facilitate the passage in the tube of a material element likely to be otherwise blocked by these pressing elements fixed in place, as a result blocking the rotation of the peristaltic pump.
This movement can be caused by the walls of the tube moving apart temporarily on the passage of this material element, the pressing element just following the movement of the wall with which it is in contact.
the compression force applied by the pressing elements on the tube in the compression position is proportional to the pumping pressure so as to adapt the compression force in order to preserve tightness,
In other words, the compression force applied by the pressing elements on the tube in the compression position is proportional to the motor torque of the rotor bearing the pressing elements and of this rotor's drive shaft.
the tube is held in place and centered in the body of the pump by fixed or mobile twin wheels, each of these twin wheels comprising a recess able to receive and guide said tube,
These twin wheels have an inner recess with a diameter substantially equal to the external diameter of the tube. The mobile twin wheels make it possible to follow the tube as it moves.
at least some of said pressing elements being rotationally mobile rollers mounted radially on a rotor and the tube substantially forming a U in the pump, the pump comprises a spacer with a thickness equal to, or substantially equal to, the thickness of the compressed tube, this spacer being placed between the arms of this U in the pump so as to allow said rollers to continue to be rotated when said rollers are no longer in contact with said tube during the rotation of this rotor, “The tube substantially forming a U” means that the tube has a semi-circular or C shape. The spacer is placed between these arms so as to form a substantially continuous driving surface for the rollers in order to keep them rotating. This thus avoids having the rollers strike the tube with a zero rotation speed and knock against the tube, which could lead to it being weakened.
The two roller assemblies are preferably mounted radially opposite each other so as to transport the largest possible quantity of material that is liquid or consists of particles or grains, such as concrete.
the pressing elements are conically-shaped mobile rollers rotating around their longitudinal axis, the rollers comprise a rounded end,
Alternatively, it is possible for the pressing elements of a same assembly not to be identical.
Thus, purely for purposes of illustration, a single pressing element may be mobile so as to allow the distance separating these pressing elements of a same assembly to be adjusted, the other pressing element being fixed and formed of a fixed wall, preferably flat.
This fixed wall may be formed by the frame of the peristaltic pump's body, for example.
Thus, when the peristaltic pump is in operation, the mobile pressing element, for example a roller, is moved to compress the tube against the fixed wall so as to cause tightness.
Advantageously, the surface of this fixed wall intended to receive the tube to be compressed can in addition comprise an adhesive coating to prevent any longitudinal sliding of this tube when it is compressed. This adhesive coating can be formed, for instance, of an elastomer strip.
the tube comprises, in its thickness, at least one layer of one or more cables placed over the primary winding diameter.
BRIEF DESCRIPTION OF THE DRAWINGS
In different possible embodiments, the invention will be described in more detail with reference to the drawings included in an appendix, in which:
FIG. 1 is a partial view in cross-section of a peristaltic pump according to the prior state of the art;
FIG. 2 is a schematic representation of a fixed set of rollers for compressing the tube of the pump in FIG. 1 ;
FIG. 3 is a schematic representation of cylindrical rollers guiding the tube of the pump in FIG. 1 ;
FIG. 4 is a schematic representation of a partial top view of a peristaltic pump according to a particular embodiment of the invention;
FIG. 5 is a schematic representation of a partial cross-section and front view of the pump in FIG. 4 , the pressing element assemblies being in compression position for compressing the tube;
FIG. 6 is a schematic representation of a partial cross-section and front view of the pump in FIG. 4 , the pressing element assemblies being in the rest position;
FIG. 7 is a schematic representation of a particular view of a twin wheels retaining the tube of the pump in FIG. 4 ;
FIG. 8 is a cross-section view of the tube of the pump in FIG. 4 , this tube being strengthened by 2 layers of several cables
FIG. 9 shows the tube in FIG. 8 in the compression position;
FIG. 10 is a top view of the tube in FIG. 8 ;
FIG. 11 is a schematic representation of a cross-section and front view of a peristaltic pump according to another embodiment of the invention, with fixed wall;
DETAILED DESCRIPTION
FIGS. 4 and 7 are schematic representations of a peristaltic pump according to a particular embodiment of the invention. This pump 1 having been realized by adapting a pump according to the prior state of the art as described in FIGS. 1 to 3 in accordance with the invention, the elements identified in FIGS. 4 to 7 by the same references as in FIGS. 1 to 3 , representing the same objects.
The two sets 4 , 5 of rollers diametrically opposite with respect to the rotor's rotational axis each comprise two rollers 20 , 20 ′, 21 , 21 ′ having a suitably angled conical shape allowing sliding between these rollers and the tube to be reduced, or even eliminated, which improves the latter's lifespan.
These conical rollers 20 , 20 ′, 21 , 21 ′ each have a rounded end 22 , 23 so that they gradually come into contact when they arrive rotating at the part of the tube placed near the inlet 12 , thus avoiding superficial tearing of the external wall of tube 9 .
Rotor 2 comprises, firstly, a fixed flange 24 driven by drive shaft 3 , itself rotated by a motor, not shown.
This rotor comprises, secondly, a flange 25 likely to pivot around an axle 26 , itself linked to a sliding ring 27 on drive shaft 3 and driven rotationally through sliding keying by said shaft 3 .
This ring 27 comprises a chamber 28 for receiving a hydraulic fluid and, with the piston 29 itself linked to axle 3 , forms an actuator jack.
At rest, this actuator jack is made to move downwards by the spring 30 pressing on the piston 29 itself linked to the axle 3 , and consequently the flange 25 linked to the ring 27 is therefore made to move downwards and the tube 9 is not compressed.
If a pressurized fluid is introduced into the chamber 28 through the aperture 31 , itself fed by a revolving joint 32 , the sliding ring 27 and, as a result, the flange 25 are moved in the opposite direction, i.e. upwards, by the actuator jack.
Consequently, if the fluid is pressurized, the mobile flange 25 is moved and the two rollers 21 , 21 ′ linked to this flange compress the tube 9 against the rollers 20 , 20 ′ mounted on the fixed flange 24 . The tube 9 is therefore compressed and said tube's tightness is ensured.
The compression force of tube 9 will be proportional to the pressure of the fluid entering the chamber 28 .
This pressure of the fluid may be proportional to the pumping pressure of the product and thus ensure the required tightness corresponding to the pumping pressure. The elastomer of the tube 9 will only be called upon as much as necessary, thus improving its life.
The powering of the shaft 3 , and therefore of the two flanges 24 , 25 , is performed by a hydraulic transmission. The rotational motor torque of the shaft 3 is proportional to the pumping pressure of the product.
The pressure of the powering hydraulic system will itself be proportional to the motor torque, thus to the pumping pressure of the product.
Therefore, if the actuator jack is powered by this hydraulic pressure, it will exert a compression force on the tube 9 proportional to the pumping pressure.
Since the flange 25 is free to pivot on its axle 26 , and slide on the shaft 3 , either one of rollers 21 , 21 ′ may be raised independently if it should encounter an aggregate blocked in the tube 9 , thus avoiding the aggregate damaging or perforating the tube 9 .
It is noted that if, when the peristaltic pump's motor is started or pumping begins, pressurized fluid is sent into the chamber 28 , the two rollers 21 , 21 ′ compress the tube 9 and thus ensure the tightness required for pumping the product.
Conversely, when the peristaltic pump's motor is stopped or pumping ceases, no more pressurized fluid is sent into the chamber 28 , the spring 30 will move the mobile flange 25 in the opposite direction and the two corresponding rollers 21 , 21 ′ will release the tube 9 , which will therefore not be compressed while the pump 1 is stopped, thus avoiding permanent deformation of the elastomer of the tube 9 . In this way, the lifespan and suction capacity of this tube are improved significantly.
If pump 1 is arranged in a substantially vertical position, as shown in FIG. 6 , it seems that the return spring 30 can be eliminated. In effect, the mobile flange 25 can descend as a result of gravity when the pressurized fluid is no longer injected.
In FIGS. 4 and 6 and the cross-section view in FIG. 7 , it is noted that the uncompressed part of the tube 9 located between the two sets 4 , 5 of rollers is held and centered by twin wheels 33 turning around their axle 34 , and positioned on the fixed flange 24 . These twin wheels 33 can also be moved axially along their axle 34 to follow the axial movements of the tube 9 , when the sets 4 , 5 of rollers are placed in their rest position or compression position.
The internal diameter of these twin wheels 33 is substantially equal to the external diameter of the tube 9 so as to help it, in addition to its own elasticity, regain its cylindrical shape and thus boost its suction power.
In this context, the twin wheels 33 advantageously replace the axial rollers 15 and radial rollers 14 of a pump according to the state of the art ( FIG. 1 ).
A spacer 35 is fixed between the inlet 12 and outlet 13 of the tube 9 , in the plane of said tube's axis. It has a thickness substantially equal to the thickness of the compressed tube 9 so as to be able to keep the rollers rotating without the mobile flange 25 having to be moved.
Thus, when one of the two sets 4 , 5 of rollers leaves the tube 9 at the outlet 13 , the rollers 20 , 20 ′, 21 , 21 ′ continue to press on this spacer 35 and therefore continue to rotate.
Also, when said rollers come into contact, at the inlet 12 of the tube 9 , they are already rotating and do not alter the external wall of said tube.
Another example of realization according to the invention, but not shown, can be formed of two symmetrically opposite assemblies of two sets of mobile flanges 25 , each equipped with a chamber 28 and a piston 29 forming an actuator jack.
Another example of realization of the invention, not shown, can be realized with more than two sets 4 , 5 of rollers.
Other examples of realizations according to the invention, not shown, can be realized by using pneumatic or hydraulic electric means that can exert a compression and withdrawal force, replacing the chamber 28 and piston 29 forming an actuator jack.
Advantageously, the tube 9 will be reinforced by a layer 40 made of one or more cables 41 , 42 , 43 arranged over said tube's primary winding diameter. This layer 40 may advantageously be supported by a second layer 41 , itself made from one or more cables 41 ′, 42 ′, 43 ′, and symmetrically opposite to said first layer.
This longitudinal layer makes it possible to retain a constant length for the tube 9 , whatever the traction force exerted by the sets 4 , 5 of rollers, and thus keep the tube centered on the sets of rollers, which allows the burdensome housing 17 utilized in pumps according to the state of the art to be eliminated.
FIG. 11 is a schematic representation of a peristaltic pump according to another embodiment of the invention. The elements in FIG. 11 bearing the same references as the elements in FIG. 6 represent the same objects, which will consequently not be described again. The peristaltic pump in FIG. 11 differs from that in FIG. 6 in that the pressing elements 21 , 21 ′, 50 of a same assembly are not identical.
The pressing element 21 , 21 ′ located below the tube 9 in each assembly is a mobile roller, while the pressing elements placed above this tube 9 are made of a single fixed flat wall 50 .
This fixed wall 50 further comprises an adhesive coating 51 intended to receive the tube 9 so as to prevent any longitudinal sliding of the latter when the tube is compressed by the pressing element assemblies 21 , 21 ′, 50 .
The drive shaft 3 crosses the fixed wall 50 and is rotationally mobile with respect to it. A stop 52 absorbs the compression forces of the tube 9 .
This peristaltic pump further comprises a spacer (not shown) with a thickness equal to, or substantially equal to, the thickness of the compressed tube 9 , this spacer being placed between the arms of said U in the peristaltic pump to allow the rollers 21 , 21 ′ placed under the tube 9 to continue being rotated when these rollers 21 , 21 ′ are no longer in contact with said tube 9 during the rotation of the rotor 2 . | The invention concerns an improved peristaltic pump including at least one elastically flattenable tube and at least two assemblies of two pressing elements placed opposite each other, each of said assemblies being configured to compress the tube at a different point from the pump. These two pressing elements of a single assembly are placed on either side of the tube, at least one of the pressing elements of this single assembly is mobile such that the distance separating the pressing elements of the single assembly is adjustable, to allow the pressing members to be placed in a rest position, in which the tube is not compressed by the pressing elements, or to allow the pressing elements to be placed in a position compressing the tube. Advantageously, the adjustment is made automatically when the peristaltic pump or pumping is started or stopped. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a technique involving the connection of solder balls (i.e. solder bumps) for electronic devices, and more particularly, to a redistribution connecting structure for solder balls.
[0003] 2. Description of the Prior Art
[0004] In the conventional art, solder balls are commonly disposed on the output terminal of electronic devices for connecting to other external devices. As the demand for product miniaturization increases, the position of solder balls must be rearranged and adjusted accordingly. As shown in FIG. 1 , a conventional redistribution connecting structure 100 includes a substrate 110 , a first dielectric layer 120 , a redistribution conductive layer 130 , a second dielectric layer 140 , and a plurality of solder balls 150 . A plurality of bonding pads 111 is disposed on the substrate 110 , in which only one bonding pad is illustrated in the figure. The first dielectric layer 120 is disposed on the substrate 110 and exposes the bonding pad 111 through a plurality of openings. The redistribution conductive layer 130 is disposed on the first dielectric layer 120 . One end of the redistribution conductive layer 130 is processed to form a plurality of redistribution pads 131 for adjusting the position of the solder balls 150 . The second dielectric layer 140 is disposed on the first dielectric layer 120 and the redistribution conductive layer 130 . Preferably, the second dielectric layer 140 includes a plurality of circular openings 141 to proportionally expose a portion of the redistribution pads 131 . The solder balls 150 are disposed on the redistribution pads 131 . A plurality of ball bases 160 is disposed under the solder balls 150 , in which the ball bases 160 are connected to the redistribution pads 131 through the openings 141 , thereby establishing a connection for the solder balls 150 .
[0005] However, when the solder balls 150 are disposed too close to the bonding pads 111 having no electrical connection thereof, a stress will result and break the connection of the solder balls 150 and cause the solder balls to peel off. If the size of the opening 141 is reduced directly, the bonding area and the adhesive ability of the redistribution pads 131 and the ball bases 160 will decrease accordingly and result in the same problem. Currently, the position of the solder balls 50 , hence the position of the opening 141 of the second dielectric layer 140 , is formed away from the bonding pads 111 having no electrical connection thereof. This design ultimately limits the redistribution effect of the solder balls 150 .
SUMMARY OF THE INVENTION
[0006] It is an objective of the present invention to provide a redistribution connecting structure to solve the aforementioned problem. According to the preferred embodiment of the present invention, a redistribution conductive layer is disposed between a first dielectric layer and a second dielectric layer on a substrate. The first dielectric layer partially exposes a plurality of bonding pads formed on the substrate, and the second dielectric layer partially exposes a plurality of redistribution pads formed on the redistribution conductive layer. Preferably, when a solder ball is disposed adjacent to a bonding pad having no electrical connection thereof and an opening of the first dielectric layer that exposes the bonding pad is covered by the surface of the solder ball, a substantially circular opening having a cut-off portion of the second dielectric layer is formed. Specifically, the opening of the second dielectric layer is formed adjacent to but not overlapping the opening of the first dielectric layer, thereby increasing the bonding area between the ball base and the redistribution pad and reducing the overall stress. Ultimately, phenomenon such as breaking or peeling of solder balls can be prevented, thus increasing the yield of the product.
[0007] According to an embodiment of the present invention, the redistribution connecting structure for solder balls includes a substrate, a first dielectric layer, a redistribution conductive layer, a second dielectric layer, at least a solder ball, and a first bonding pad and a second bonding pad disposed on the substrate. The first dielectric layer is disposed on the substrate, in which the first dielectric layer includes a first opening and a second opening partially exposing the first bonding pad and the second bonding pad. The redistribution conductive layer is formed on the first dielectric layer. The redistribution conductive layer includes a first redistribution pad and a second redistribution pad, in which the first redistribution pad is electrically connected to the first bonding pad through the first opening, and the second redistribution pad is electrically connected to the second bonding pad through the second opening. The second dielectric layer is formed on the first dielectric layer and the redistribution conductive layer. The second dielectric layer includes a third opening and a fourth opening, in which the third opening partially exposes the first redistribution pad and the fourth opening partially exposes the second redistribution pad. The solder ball is disposed on the first redistribution pad. The area of the solder ball preferably covers the third opening and a portion of the second opening. The third opening is substantially circular and disposed adjacent to but not overlapping the second opening, in which the third opening further includes a cut-off portion. By using this design, the solder ball can be disposed above the electrically insulated second bonding pad, thus reducing the overall stress and the eliminating the need for having additional redistribution conductive layers.
[0008] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a cross-section of a redistribution connecting structure for solder balls according to the prior art.
[0010] FIG. 2A illustrates a top-view of a redistribution connecting structure for solder balls according to the first embodiment of the present invention.
[0011] FIG. 2B illustrates a cross-section of the redistribution connecting structure of FIG. 2A along the sectional line 2 B- 2 B.
[0012] FIGS. 3A , 4 A, and 5 A illustrate a top-view of a redistribution connecting structure for solder balls during the fabrication process according to the first embodiment of the present invention.
[0013] FIGS. 3B , 4 B, and 5 B illustrate a cross-section of a redistribution connecting structure for solder balls during the fabrication process according to the first embodiment of the present invention.
[0014] FIG. 6 illustrates a cross-section of a redistribution connecting structure for solder balls according to the second embodiment of the present invention.
DETAILED DESCRIPTION
[0015] FIG. 2A illustrates a top-view of a redistribution connecting structure 200 for solder balls (i.e. solder bumps) according to the first embodiment of the present invention. FIG. 2B illustrates a cross-section of the redistribution connecting structure 200 of FIG. 2A along the sectional line 2 B- 2 B.
[0016] As shown in FIGS. 2A and 2B , the redistribution connecting structure 200 includes a substrate 210 having a plurality of bonding pads 211 , a first dielectric layer 220 , a redistribution conductive layer 230 , a second dielectric layer 240 , and a plurality of the solder balls 250 . The solder balls 250 include at least a first solder ball 251 and a second solder ball 252 , and the bonding pads 211 include a first bonding pad 211 A and a second bonding pad 211 B disposed on the substrate 210 . The redistribution conductive layer 230 is used to electrically connect the first solder balls 251 and the first bonding pad 211 A, and electrically connect the second solder ball 252 and the second bonding pad 211 B, as shown in FIG. 2A and FIG. 4A . Preferably, the first solder ball 251 is disposed on the second bonding pad 211 B and the first redistribution pad 231 A of the redistribution conductive layer 230 , and the second bonding pad 211 B is electrically connected to the solder ball 251 without going through the redistribution conductive layer 230 . The substrate 210 of the present embodiment is preferably an integrated circuit die, a ceramic substrate, a plastic substrate, a printed circuit board, or a flexible circuit board.
[0017] Please refer to FIG. 2B and FIGS. 3A and 3B . The first dielectric layer 220 is formed on the substrate 210 , in which the first dielectric layer 220 includes a plurality of openings 221 for exposing the surface of the bonding pads 211 . The openings 221 include a first opening 221 A and a second opening 221 B, in which the first opening 221 A partially exposes the first bonding pad 211 A and the second opening 221 B partially exposes the second bonding pad 211 B. In the present embodiment, the bonding pads 211 , including the first bonding pad 211 A and the second bonding pad 211 B, are formed in a shape of a rectangle or a square. The openings 221 , including the first opening 221 A and the second opening 221 B are formed in a shape of a circle. Preferably, the area of the openings 221 is smaller than the area of the bonding pads 211 , and the first dielectric layer 220 is composed of phosphosilicate glass, polyimide, or benzocyclobutene.
[0018] Please refer to FIG. 2B and FIGS. 4A and 4B . As shown in FIG. 2B and FIGS. 4A and 4B , the redistribution conductive layer 230 having a plurality of redistribution pads 231 is disposed above the first dielectric layer 220 , in which the redistribution conductive layer 230 is electrically connected to the corresponding bonding pads 211 through the opening 221 of the first dielectric layer 220 . The redistribution conductive layer 230 is preferably composed copper, aluminum, or other conductive metal. The redistribution pads 231 include a first redistribution pad 231 A disposed on the upper right corner of FIG. 4A and a second redistribution pad 231 B disposed on the upper corner of FIG. 4A . The first redistribution pad 231 A is disposed adjacent to the second redistribution pad 211 B and electrically connected to the first bonding pad 211 A through the first opening 221 A, and the second redistribution pad 231 B is electrically connected to the second bonding pad 211 B. In the present embodiment, the first redistribution pad 231 A and the portion connecting the redistribution conductive layer 230 and the second bonding pad 211 B are located adjacent to each other and in the same level, thus resulting in a non-perfect circular shape.
[0019] Please refer to FIG. 2B and FIGS. 5A and 5B . As shown in FIG. 2B and FIGS. 5A and 5B , the second dielectric layer 240 is disposed on the first dielectric layer 220 and the redistribution conductive layer 230 , in which the second dielectric layer 240 includes a plurality of openings 241 for exposing the redistribution pads 231 . In the present embodiment, the openings 241 include a third opening 241 A and a fourth opening 241 B, in which the third opening 241 A partially exposes the first redistribution pad 231 A and the fourth opening 241 B partially exposes the second redistribution pad 231 B. As shown in FIGS. 2A and 2B , the solder balls 250 are disposed on the redistribution pads 231 , in which the first solder ball 251 is disposed on the first redistribution pad 231 A and the second solder ball 252 is disposed on the second redistribution pad 231 B. Preferably, the area 253 of the first solder ball 251 also covers the third opening 241 A and a portion of the second opening 221 B. Referring to FIG. 5A and 5B , since the third opening 241 A includes a substantially circular shape and a cut-off portion, the third opening 241 A is formed adjacent to the second opening 221 B but not overlapping the second opening 221 B. In the present embodiment, the edge of the cut-off portion of the third opening 241 A includes two straight lines for forming an included angle, thus resulting a substantially C-shaped third opening 241 A. Additionally, as shown in the right region or lower left side of FIG. 5A , the edge of the cut-off portion of the openings 241 can be a straight line, thus forming a portion of the openings 241 into a substantially D shape.
[0020] As shown in FIG. 2A , the distance d between the edge of the second opening 221 B and the center of the third opening 241 A is less than the radius r of the third opening 241 A. Hence, the third opening 241 A of the second dielectric layer 240 that located in a relatively upper level, is not affected by the position of the second opening 221 B of the first dielectric layer 220 that located in a relatively lower level, thereby providing adequate electrical barrier between the first redistribution pad 231 A and the adjacent second bonding pad 211 B and providing enough adhesion area for the first redistribution pad 231 A.
[0021] The first solder ball 251 can be disposed above different second bonding pads 211 B that are electrically insulated to each other, thus increasing the bonding area between the first redistribution pads 231 A and the ball base 260 positioned under the solder ball 251 and eliminating the need for forming additional layers for the redistribution conductive layer 230 . As shown in FIG. 2B , the redistribution connecting structure 200 also includes at least a ball base 260 , in which the ball base 260 can be a conventional under bump metallurgy (UBM) structure composed of titanium/nickel-vanadium/copper, nickel/gold, nickel/copper, chromium/chromium-copper/copper. The ball base 260 is positioned on the redistribution pads 231 for connecting the solder balls 250 . Additionally, the ball base 260 is substantially circular and disposed on the second dielectric layer 240 , and the ball base 260 is connected to the first redistribution pad 231 A through the third opening 241 A. The ball base 260 is also extended to the top of the second opening 221 B for adjusting the position of the solder ball 251 , in which the area 253 of the solder ball covers the second opening 221 B and at least a portion of the second bonding pad 211 B.
[0022] The second embodiment of the present invention discloses another redistribution connecting structure for solder balls. As shown in FIG. 6 , a redistribution connecting structure 300 for solder balls is provided. The redistribution connecting structure 300 includes at least a bonding pad 311 disposed on a substrate 310 of an integrated circuit chip. The substrate 310 includes a first dielectric layer 320 composed of phosphosilicate glass (PSG), silicon nitride, silicon dioxide, or polyimide thereon and an opening 321 for exposing the bonding pad 311 . A redistribution conductive layer 330 composed of copper, aluminum, alloy thereof, or other composite metals is formed on the first dielectric layer 320 . The redistribution conductive layer 330 includes at least a redistribution pad 331 disposed adjacent to the bonding pad 311 and electrically connected to the bonding pad 311 through the opening 321 . The size of the redistribution pad 341 is preferably larger than the bonding pad 311 . A second dielectric layer 340 (also refers to as a passivation layer) is disposed on the first dielectric layer 320 and the redistribution conductive layer 330 . The second dielectric layer 340 includes a non-circular opening 341 for exposing the redistribution pad 331 , in which the non-circular opening 341 is typically smaller than the redistribution pad 331 . Additionally, at least a substantially circular ball base 350 (also refers to as an UMB pad) is disposed on the second dielectric layer 340 , in which the ball base 350 is extended to the top of the opening 321 and connected to the redistribution pad 331 through the non-circular opening 341 . The ball base 350 is composed of a plurality of metal layers, including an adhesion layer, a barrier layer, and a wetting layer. The ball base 350 includes at least a solder ball 360 thereon. Referring to FIG. 6 , the area 361 of the solder ball 360 covers the non-circular opening 341 and the opening 321 of the first dielectric layer 320 . The non-circular opening 341 includes a similar cut-off portion as described in the first embodiment, such that the non-circular opening 341 is adjacent but not overlapping the opening 321 of the first dielectric layer 320 . In other words, the redistribution conductive layer 330 of the redistribution connecting structure 300 includes a redistribution pad 331 disposed adjacent to the bonding pad 311 , such that the non-circular opening 341 of the second dielectric layer 340 that exposes the redistribution pad 331 can be used to increase the adhesion area of the ball base 350 . By using the second dielectric layer 340 to cover the top portion of the opening 321 , the thermal stress created with respect to the junction between the ball base 350 and the redistribution pad 331 is reduced significantly. Ultimately, the size and position of the ball barrier 350 can be adjusted accordingly, thereby preventing peeling or breakage of the solder ball 360 and increasing the yield of the product.
[0023] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | A redistribution connecting structure for solder balls is disclosed. A substrate includes a plurality of bonding pads. A plurality of dielectric layers, a redistribution conductive layer between the dielectric layer, and a plurality of solder balls are formed on the substrate. The redistribution layer has a redistribution pad disposed adjacent to one of the bonding pads without electrical connection with the redistribution pad. One of the dielectric layers covering the redistribution conductive layer has an opening to partially expose the redistribution pad, in which the opening is approximately circular and has a cut-off portion so that the opening is adjacent to an opening of another of the dielectric layers exposing one of the bonding pads without overlapping. Accordingly, bonding area of the redistribution pad for a bonding pad under one of the solder balls can be expanded to reduce stress effect. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to surgical devices and methods of soft tissue remodeling.
[0002] The present invention relates to a new method of soft tissue remodeling to counteract the effects of aging on a person's face and other parts of the body. As a person ages, the skin begins to loosen, sag, and develop wrinkles. In addition to the skin, the supporting structures also relax. Various cosmetic surgical procedures and techniques have been used to remodel the soft tissue, such as a facelift, browlift, necklift, or blepharoplasty. These surgical procedures can incorporate large incisions. Optimally, it would be best to use a few small incisions. It is difficult to uniformly redistribute the tissue using just one or two small incisions without exerting excessive tension on one area of the soft tissue that would produce an unnatural or pulled result.
[0003] Consequently, there is a need for further improvement in the relative area including surgical devices and techniques that allow a surgeon to remodel soft tissue to provide a yet produce a pleasing, natural result. The present invention addresses the above-described problems and provides additional benefits and advantages.
SUMMARY OF THE INVENTION
[0004] The present invention includes a fixation device, which is placed within the soft tissue, and has prongs on one end and multiple holes on the other end. It also comprises an insertion tool, which allows deployment of this fixation device within the soft tissue for accurate lifting and fixation of the soft tissue to a higher level. There is a locking mechanism on the insertion tool, which allows the fixation device to be held until engagement into the soft tissue is desired. This allows for accurate and adjustable tension on the various depths of the soft tissue. The surgical treatment will consist of making an incision in the patient's soft tissue, inserting the fixation device using the insertion tool, and slowly advancing the fixation member through the insertion tool to engage each successive set of prongs into the soft tissue and applying tension to the fixation device as each prong is being engaged. This successive pull will remodel the soft tissue accurately and allow for adjusting to the individual patient.
[0005] In one form, the present invention provides a medical device for treatment of soft tissue. The device comprises an insertion tool that resembles a hypodermic-like tool defining a lumen therethrough. The insertion tool has an insertion end and an opposite, hub end. The device also includes a fixation member that is slidably received within the lumen. The fixation member includes an elongate shaft having a first end and an opposite second end and includes a plurality of prongs fixedly attached to the shaft adjacent the first end and a plurality of holes adjacent the second end.
[0006] In preferred embodiments, the insertion tool can also include a locking mechanism or assembly to enable the surgeon to secure the fixation member in the lumen at a first position. The locking mechanism can be released to allow the surgeon to deploy the fixation member to a second position so that the prongs can engage the soft tissue.
[0007] In another form, the present invention provides a method of surgical treatment for a patient. The treatment comprises: making an incision in the patient's soft tissue; inserting into the incision a tissue remodeling device including an elongate tissue fixation member having a plurality of tissue engaging prongs disposed within an insertion tool; advancing the tissue fixation member through the insertion tool to engage at least a first one of the plurality of prongs to the soft tissue; and applying tension to the elongate tissue fixation member to effect remodeling of the engaged soft tissue.
[0008] In still yet another form, the present invention provides a method of surgical treatment to remodel tissue of a patient. The method comprises making an incision in the tissue of the patient; providing an insertion tool having a lumen and locking assembly and including a fixation member having at least one prong extending outwardly therefrom; and deploying a length of said fixation member into said incision, wherein said fixation member attaches to and lifts the patient's tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of one embodiment of the tissue remodeling assembly in accordance with the present invention.
[0010] FIG. 2 is an exploded view of the tissue remodeling assembly illustrated in FIG. 1 .
[0011] FIG. 3 is a cross-sectional view of one embodiment of an insertion tool with a tissue piercing tip in accordance with the present invention.
[0012] FIG. 4 is a plan view of one embodiment of a tissue fixation member in accordance with the present invention.
[0013] FIG. 5 is an enlarged view of a portion of the fixation member of FIG. 4 illustrating two tissue engaging prongs in accordance with the present invention.
[0014] FIGS. 6a and 6b are end views of various fixation members having differing patterns and/or numbers of tissue engaging prongs.
[0015] FIG. 7 is a cross-sectional view of a tissue remodeling assembly having a fixation member disposed in the insertion tool in accordance with the present invention.
[0016] FIG. 8 is a cross-sectional view of the tissue remodeling assembly of FIG. 7 illustrating that a portion of the fixation member can extend beyond the end of the insertion tool in accordance with the present invention.
[0017] FIG. 9 is an illustration of the tissue remodeling assembly in use in accordance with the present invention.
[0018] FIG. 10 is an illustration of the fixation member holding the remodeled tissue in place in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated herein and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described devices and/or methods, and any further applications of the principles of the invention as described herein, are contemplated as would normally occur to one skilled in the art to which the invention relates.
[0020] FIG. 1 illustrates one embodiment of a tissue remodeling assembly 20 in accordance with the present invention. Tissue remodeling assembly 20 includes an insertion tool 21 and fixation member 22 , which is loaded within the insertion tool. In addition, insertion tool 21 includes a locking assembly 24 to secure and engage the fixation member within.
[0021] Referring now additionally to FIG. 2 , in the illustrated embodiment insertion tool 21 is a substantially hollow, hyperdermic-like tool or cannula having a lumen extending through it and with a removable cap 23 at its end. The shaft 30 of the insertion tool terminates on a first end in insertion end 26 and on an opposite end in hub end 28 . The outer diameter of insertion tool 21 is sized to permit minimally invasive surgical procedures. The inner diameter or lumen of insertion tool 21 is sized to accept various sizes of fixation members. Examples of specific sizes of fixation devices are preferably between 2 and 5 mm in diameter.
[0022] Insertion tool 21 is illustrated as a straight shaft. However, it could be configured to compensate for the natural anatomical features of the human anatomy.
[0023] FIG. 3 is a cross sectional view of insertion tool 21 showing its hollow core or lumen 32 and locking assembly 24 to releasably retain the fixation member 22 . Locking assembly 24 can be configured to releasably secure the fixation member at a fixed location or depth within the lumen 32 of shaft 30 . In the illustrated embodiment, locking assembly 24 includes a pin 34 extending through hub end 28 and into lumen 32 . Pin 34 is configured to engage with a corresponding hole or recess on the fixation member (described more fully below). Locking assembly 24 can be biased to retain its position. In one embodiment, locking assembly 24 is biased to force pin 34 to engage with the fixation member received within lumen 32 . In an alternative embodiment, locking assembly 24 is biased to force pin 34 to be retracted within the body of hub end 28 and in a non-engaging arrangement with the included fixation member.
[0024] In a preferred embodiment, tissue insertion end 26 can include tissue piercing cap 23 removably secured thereon. Tissue piercing cap 23 can be configured with a sharp point to easily pierce tissue with minimal (if any) tearing.
[0025] Hub end 28 can be flared and configured to facilitate the gripping and placement of the insertion tool in a desired location. In one embodiment, hub end 28 is provided to have an enlarged exterior diameter to facilitate gripping by the surgeon during use.
[0026] Insertion tool 21 can be formed of a variety of rigid biocompatible materials as desired. Preferred materials include stainless steel and surgical steel.
[0027] FIG. 4 is a plan view of one embodiment of a fixation member 22 for use in the present invention. Fixation member 22 is provided as an elongate shaft 40 that can be provided as a flexible, thin biocompatible cord or rod suitable for implantation into a patient to remodel tissue. In the illustrated embodiment, shaft 40 is configured to exhibit a substantially cylindrical configuration, having a preferred diameter of at least about 2 mm and more preferably at least about 4 mm. For larger areas of tissue lifting, a larger fixation device can be used. It will be understood that shaft 40 can be provided in other configurations including, without limitation, configurations that have a cross section including a rectangle, a square, an oval, or the like in various sizes. The length of fixation member 22 can vary depending upon the area of tissue remodeling.
[0028] Shaft 40 includes a first end 46 and an opposite second end 48 . First end 46 can include one or more eyes or apertures 50 suitable for receiving a length of suture. The suture can be used to either secure the tip to tissue and/or facilitate retrieval of the fixation member.
[0029] A plurality of tissue engaging prongs 52 are also located adjacent first end 46 . The prongs extend from the external surface 54 of shaft 40 and are spaced axially from each other. In one embodiment, the prongs are grouped into a plurality of sets of prongs with each set of prongs spaced axially from the other sets. The sets of prongs can include two, three, or more prongs extending symmetrically or asymmetrically about shaft 40 . Preferably, the prongs are positioned at 90°, 120°, or 180° from each other. However, it will be understood the prongs can be positioned as needed or desired for the specific tissue to be lifted. Preferably prongs 52 are flexible. Consequently, the prongs 52 may be compressed when inside insertion tool.
[0030] Second end 48 of shaft 40 is substantially free of any tissue engaging structures. However, second end 48 includes a plurality of holes. Each of holes 66 , 68 , and 70 can be provided as an aperture extending completely through shaft 40 or as a recess or indent extending partly through shaft 40 . Each hole can be spaced from an adjacent hole that corresponds to the axial spacing between adjacent prongs.
[0031] The holes can act as a guide for the surgeon to accurately gauge the length of the flexible device that has been pushed out the distal, first end 46 . In addition or in the alternative, second end 48 can also include a number of indexing marks or other indicia 86 representative of a unit of length that first end 46 extends beyond insertion end 26 of insertion tool 21 . Alternatively, the indexing marks or other indicia 86 can be representative of the number of sets of prongs, that extend beyond the insertion end 26 of insertion tool 21 .
[0032] Additionally, second end 48 can include a plurality of apertures 84 extending through shaft 40 through which sutures can be threaded to secure fixation member 22 to soft tissue or bone. In one particularly preferred embodiment, the plurality of apertures 84 can also serve or function as holes 68 to engage with pin 34 of locking assembly 24 .
[0033] FIG. 5 is an exploded view of one set of prongs 78 . In the illustrated embodiment, set of prongs 78 includes two prongs 80 and 82 extending from shaft 40 . Each of prongs 80 and 82 are provided to exhibit the profile of a barb or tine to engage and grip surrounding soft tissue. Preferably, prongs 80 and 82 are configured to be easily inserted in tissue in a first direction but difficult to remove from that same tissue when moved or pulled in an opposite, second direction.
[0034] FIGS. 6 a and 6 b are illustrations a first end view of various shafts for use in the present invention. FIG. 6 a illustrates a fixation member 90 having a two prongs 94 , and 96 arranged symmetric or diametrically each other about shaft 100 . In FIG. 6 b , fixation member 132 includes three prongs 134 , 136 , and 138 . As can be seen from the illustrated embodiment, the base of each of prongs 134 , 136 , and 138 are located on the same hemispherical section of the cylindrical shaped fixation member 132 . Consequently, each of prongs 134 , 136 , and 138 are asymmetrically distributed about the outer circumference of fixation member 132 .
[0035] Fixation member 22 can be composed of a biocompatible material. The biocompatible material can either be biodegradable or non-biodegradable. Non-limiting examples of non-biodegradable materials for use in the present invention include TEFLON® and polypropylene. In one form, fixation member 22 is provided as a biodegradable material that can slowly degrade in vivo over a period of time ranging between about 6 months and about 24 months.
[0036] FIG. 7 is a cross-sectional view of tissue remodeling assembly 20 illustrating fixation member 22 received within lumen 32 . In this illustration, it can be observed that the fixation member and the plurality of prongs 52 are sized such that the plurality of prongs 52 are deflected or compressed against the inner wall 36 of lumen 32 . Tissue piercing cap 23 is secured to the tissue engaging end of insertion tool 21 . On the opposite end of tissue insertion tool 21 , locking assembly 24 is provided in a first position whereby pin 34 engages with an hole 66 to axially lock fixation member 22 within lumen 32 . It can also be observed that second end 48 of fixation member 22 is exposed beyond hub end 28 . Index mark 86 indicates how much of fixation member is exposed.
[0037] FIG. 8 is an illustration of tissue remodeling assembly 20 in which tissue piercing cap 23 has been removed. Fixation member 22 has been extended such that first end 46 extends beyond insertion end 26 , exposing at least a first set of prongs 56 . Additionally, it can be observed that a thread or suture 50 has been inserted through the opening 51 in first end 46 of fixation member 22 .
[0038] In the illustration, locking assembly 24 has been adjusted to position pin 34 to end through a second hole 68 , thereby locking fixation member 22 as desired in the interior lumen 32 of insertion tool 21 . In this embodiment, insertion tool 21 can be manipulated to either further insert the insertion tool into tissue or to begin pulling and extracting the insertion tool out of the adjacent soft tissue to begin to effect tissue remodeling.
[0039] FIG. 9 is a schematic illustration of the tissue remodeling assembly 20 in use to accomplish tissue remodeling such as that prescribed for a face lift. However, it should be understood that tissue remodeling assembly 20 of the present invention could be used in any general surgical procedure to manipulate soft tissue in other areas of the body.
[0040] A small incision will be made in the temple area of the face and the insertion tool with the loaded fixation device will be placed through this incision and brought down into the buccal or cheek sulcus of the mouth. Because of the removable cap on the insertion end of the tool, non-traumatic passage of this tool can be accomplished. The removable cap is then removed within the mouth and a suture placed through the single hole on the distal end of the fixation device. This is used to stabilize the fixation device initially and to allow removal of the fixation device if it is found not to be in the correct position. The surgeon will then begin the engagement of the fixation device within the soft tissue. This will be accomplished by pushing the fixation device out of the insertion tool slowly. As each prong is released from within the insertion tool, it will then spring open and engage the soft tissue. By placing tension on the insertion tool, elevation of this specific soft tissue can be done. When the proper lift is produced in this part of the soft tissue, another prong can be released and engaged and again, tension and lift can be placed on the second prong, which will then lift this second area of soft tissue. By alternately releasing a prong and lift, an accurate remodeling of the soft tissue can be done. When all the prongs are released, the excess portion of the fixation device can be cut and discarded, leaving the remaining portion with holes to be fixed to the soft tissue in the temple area. The incision in the temple area then can be easily closed ( FIG. 10 ). A second fixation device can be placed in adjacent tissue if desired through the same or a separate incision. Because each of the fixation device prongs can be deployed individually and tension adjusted for each set of prongs, accurate remodeling of the soft tissue can be accomplished.
[0041] The present invention contemplates modifications to the tissue remodeling assembly and its components as would occur to those skilled in the art. It is also contemplated that processes embodied in the present invention can be altered, rearranged, or added to other surgical procedures or medical treatments as would occur to those skilled in the art without departing from the spirit of the present invention.
[0042] Unless specifically identified to the contrary, all terms used herein are used to include their normal and customary terminology. Further, while various embodiments of the tissue remodeling assembly, insertion tool, and fixation member having specific components, prongs, dimensions, and structures are described and illustrated herein, it is to be understood that any selected embodiment can include one or more of the specific components and/or structures described for another embodiment where possible.
[0043] Further, any theory of operation, proof, or finding stated herein is meant to further enhance understanding of the present invention and is not intended to make the scope of the present invention dependent upon such theory, proof, or finding.
[0044] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is considered to be illustrative and not restrictive in character, it is understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | A surgical apparatus with an insertion tool and fixation device for lifting or remodeling soft tissue as described. A combination of a fixation device and insertion tool allows for incremental release and engagement of the fixation device, which is supplied with prongs to grasp the soft tissue and hold on the other end to allow suture lifting of the soft tissue. The careful deployment of the fixation device and the manipulation and tension on the insertion tool allows a gradual, adjustable, and uniform lifting of the soft tissue that are to be remodeled. | 0 |
CROSS-RELATED DOCUMENTS
[0001] The present invention is related in part to prior U.S. Pat. No. 5,765,033 issued on Jun. 9, 1998 to inventor Alec Miloslavsky entitled System for Routing Electronic Mails. The disclosure of the prior application is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is in the field of e-mail communication and pertains more particularly to methods and apparatus for providing an enhanced e-mail client having programmable multi-address attributes.
BACKGROUND OF THE INVENTION
[0003] Electronic mail (e-mail) has become one of the most commonly used communication tools in business and in the home. E-mail comprises electronic documents having a particular protocol for addressing, such as “send to”. “from”, and “reply to” addresses, and requires compatible software applications on the part of both sender and recipient for handling the protocol. Such an application in the art is termed an e-mail client, and this term will be used frequently in the present application, meaning the control routines used for processing e-mails, including reading, replying, and the like.
[0004] Typically, an e-mail message is temporarily stored in an e-mail server connected to a data-network, and users may retrieve the stored messages from such a server at their convenience. Most e-mail clients allow a wide variety of options to a user regarding such e-mail attributes as language type, encryption methods, list mailing capability, document attaching capability, profile options, and so on. Also, user and client information may be easily stored in an address book (database) for simple retrieval and implementation.
[0005] Although many companies recognize the benefit of using e-mail, some of them have only recently installed e-mail systems. One reason for this is because e-mail applications of current art are largely proprietary and some do not communicate using the same protocol as another application. Therefore, additional steps may be required by a sender to configure his or her e-mail so that a particular receiver using a variant application may be able to read it. Often, these prerequisites are forgotten when a user sends an e-mail to a recipient necessitating a resend of the same message. More recently, however, e-mail protocol has become much more standardized, and e-mails may typically be processed over different networks and through different servers and services.
[0006] Recently, too, many companies and homes have been connected to the Internet, which is a world-wide public data network connecting tens of millions of computers. One of the reasons for the Internet's popularity is that the cost of access is very low. Another reason is that the Internet offers many resources in addition to e-mails. Each user of the Internet is typically assigned an e-mail address that is recognizable around the world. A computer connected to the Internet, having an e-mail client installed, can send e-mails to any one of these e-mail addresses, however, the proprietary nature of the client software may still require additional steps to be taken before one can send a message to a recipient using a variant application such as initiating variable coding, and so on.
[0007] As a result of the popularity and convenience of e-mails, particularly over the Internet, some companies now encourage their customers to send comments and request information and services using e-mails. Typically, these companies set up one or more specific e-mail addresses for these purposes, such as sales@xyz.dom, support@xyz.dom etc., and e-mail servers handling incoming mails may be a part of telephony call centers wherein agent stations are enabled with computer stations connected to the e-mail server.
[0008] In such e-mail systems there is still a pronounced problem and unmet need that may occur under certain conditions. For example, in some call-center environments wherein e-mail is supported, a number of agents may represent a number of different companies, being responsible for all communication including e-mail with the customers of those companies. In such a call center, it is desirable that agents be able to respond to customers with an e-mail reply having a “from” and a “reply to” address which refers to the company the customer has addressed originally.
[0009] The present problem is, that with current art e-mail clients, the return address is a default of the client for a profile, in some cases, and not a variable that an agent can manipulate, or that may change automatically depending on some attribute of a received message, without restarting the client, which can be very time consuming. When replying to a customer, default settings automatically insert the default “from” and “reply to” e-mail address into the reply. While most current art e-mail clients support the use of multiple profiles, a user must log-in to each profiles and may use only one at a time. Creating many profiles can be time consuming, and changing profiles during work of answering e-mails is clumsy and inefficient.
[0010] What is clearly needed is an e-mail client application that may automatically choose and insert addresses in the appropriate field box of an e-mail reply to an original message, or at least provide selectable options for such addresses to an agent or other user. An application such as this would save time and enable one agent to handle e-mail communications to customers of many different companies,. and, in the case of automatic insertion in response to characteristics of an original message, avoid any danger of inserting a wrong or misleading address.
SUMMARY OF THE INVENTION
[0011] In a preferred embodiment of the present invention an e-mail application is provided, comprising routines adapted for providing an interactive display on a computer video monitor, the interactive display including a window for displaying a received e-mail from a sender and a window wherein a user may enter a reply to the sender and initiate sending of the reply; a parser for reviewing at least the “send to” address of the received e-mail; and a table look-up function for perusing a stored table relating received “send to” addresses with “reply to” and “from” addresses to be inserted in prepared replies. The application retrieves from the stored table “send to” and “from” addresses to be inserted in prepared replies according to the “send to” address in the received e-mail, and inserts the retrieved addresses in the reply.
[0012] In one embodiment the parser is adapted to review the received e-mail message for addresses, words and phrases for comparison to prestored words and phrases in the stored table, and the application is adapted to insert any one of “send to”, “from”, and “reply to” addresses in a reply to the received e-mail. In an alternative the stored table stores complete reply messages associated with one or more of selected words, phrases, or addresses, and wherein the application is adapted to automatically prepare and send replies with prestored messages and addresses in response to received e-mails containing the selected words, phrases, or addresses. In another alternative, the parser is adapted to retrieve the “send to” address of the received e-mail and to compare same with addresses in a stored table associated with other “send to” addresses, and, finding a match, the application is adapted to forward the received e-mail automatically to the associated “send to” address in the stored table.
[0013] In some embodiments the application, finding a match in the stored table with the “send to” address from the received e-mail, the application is adapted to send a new e-mail to the associated “send to” address from the table, inserting the message of the received e-mail.
[0014] In alternative embodiments the e-mail client of the invention simply provides variable fields wherein a user may enter “from” and “reply to” addresses in replies to e-mails, either directly or by selection from an address book.
[0015] Methods for practicing the invention as well as apparatus are taught in several examples in the descriptions that follow under the title “Descriptions of the Preferred Embodiments.
[0016] In another aspect of the invention an e-mail handling system is provided, comprising a computer station having a video display unit (PC/VDU); an interactive display on the VDU having windows for displaying the received e-mail and for preparing a reply e-mail to the received e-mail; e-mail processing routines executable on the computer station, the e-mail processing routines comprising a parser for reviewing at least the “send to” address of the received e-mail; and a table look-up function for perusing a stored table relating received “send to” addresses with “reply to” and “from” addresses to be inserted in prepared replies. The e-mail processing routines retrieve from the stored table “send to” and “from” addresses to be inserted in prepared replies according to the “send to” address in the received e-mail, and inserts the retrieved addresses in the reply.
[0017] In a particular embodiment of the system according to the invention the parser is adapted to review the received e-mail message for addresses, words and phrases for comparison to prestored words and phrases in the stored table, and the e-mail processing routines are adapted to insert any one of “send to”, “from”, and “reply to” addresses in a reply to the received e-mail. In another embodiment the stored table stores complete reply messages associated with one or more of selected words, phrases, or addresses, and the application is adapted to automatically prepare and send replies with prestored messages and addresses in response to received e-mails containing the selected words, phrases, or addresses. In still another embodiment the parser is adapted to retrieve the “send to” address of the received e-mail and to compare same with addresses in a stored table associated with other “send to” addresses, and, finding a match, and the e-mail processing routines are adapted to forward the received e-mail automatically to the associated “send to” address in the stored table. In yet another embodiment of the system, upon finding a match in the stored table with the “send to” address from the received e-mail, the e-mail processing routines are adapted to send a new e-mail to the associated “send to” address from the table, inserting the message of the received e-mail.
[0018] In the various embodiments and aspects of the invention taught below in enabling detail, an e-mail client application is provided that may be conveniently used by an agent who may receive e-mails addressed to different companies or organizations, and reply to such messages in a manner that different “from” and “reply to” addresses are inserted automatically as though the one agent were different agents of different organizations. In this manner one agent may represent several different entities without danger of inserting wrong or confusing data in e-mail replies.
[0019] In alternative embodiments the e-mail client of the invention simply provides variable fields wherein a user may enter “from” and “reply to” addresses in replies to e-mails, either directly or by selection from an address book.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0020] [0020]FIG. 1 is a diagram of an e-mail processing center using a multi-adressable e-mail client according to an embodiment of the present invention.
[0021] [0021]FIG. 2 is a flow chart illustrating steps in a method according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] [0022]FIG. 1 is a diagram of an e-mail processing center 9 using a multi-addressable e-mail client according to an embodiment of the present invention. E-mail processing center 9 is provided for the purpose of processing, configuring, and routing e-mails arriving from a data network I 1 according to U.S. Pat. No. 5,765,033. Center 9 may be part of a computer-enhanced call-center as shown in this embodiment, or may be part of a data network telephony (DNT) center. Data network 11 may be the Internet or another wide area network (WAN) such as a private corporate network.
[0023] For the purposes of describing the present invention in its several aspects, assume that e-mail processing center 9 accepts and processes e-mails that are addressed to a plurality of different companies that are, in this case, represented by agents working in a single computer-enhanced call center, which enhancement is referred to in the art as computer-telephony integration (CTI). In such a center any single agent may represent several companies. Customers of various companies may send e-mails addressed to their represented companies via computers such as computers 13 , 15 , and 17 illustrated as connected through data network 11 . Because the companies in question have arranged and contracted to have their inquiries answered via agent personnel at the call center, e-mails addressed to any one of those companies are directed to an e-mail server at the call center by any one of several possible routes or methods not particularly pertinent to the present invention, except that such e-mails arrive at the call center and are distributed to agents at the call center with the “send to” address intact, representing the company to which the customer has directed the e-mail.
[0024] An e-mail server to CTI server adapter 25 , hereinafter termed CTI adapter 25 , is provided in this embodiment for the purpose of creating notification events and changing certain e-mail attributes for routing purposes so that normal CTI routing of e-mails via existing routing software may be performed as described in the prior related U.S. Pat. No. 5,765,033. All e-mails arriving at e-mail server 23 will be routed to available agents based on skill and as otherwise defined with reference to the prior case.
[0025] A local area network (LAN) 27 provides connectivity between a host of machines adapted to enable the e-mail routing system. A router 29 is provided for the routing of e-mails to agents operating LAN-connected computers such as computers 21 and 19 . A stat-server 31 is provided and maintains statistical information as well as near real-time information regarding agent status, agent responsibilities, language and skill attributes as applied to individual agents, and so on.
[0026] A database 35 is provided and contains in this embodiment information regarding customers, products, represented company data, and so on. A CTI server 37 is provided for the purpose of enabling existing telephony applications to communicate with the stat-server 31 , router 29 , and database 35 , and to provide other enhanced services to the call center. A skilled artisan will recognize that there will typically be a telephony switching apparatus with incoming trunks and telephones at agent stations connected to the switching apparatus as well as the computer for handling e-mails, although none of these entities are shown in FIG. 1. Also, as previously described, CTI server 37 may aid in routing e-mails after certain attributes are changed at CTI-server adapter 25 .
[0027] Once an agent has received notification of a routed e-mail, he may retrieve the actual e-mail from e-mail server 23 , or e-mails may be routed automatically to agents based on any of a number of criteria, as described in the prior referenced patent. For the purpose of the present invention the method by which the agents receive e-mails is not particularly relevant.
[0028] Agents logged on to the system via connected computers 19 and 21 have e-mail clients 39 and 41 according to an embodiment of the present invention installed and operable. E-mail clients 39 and 41 may be the same software application, different versions of the same application, or different applications that are enhanced with the same functionality as provided according to an embodiment of the present invention. The innovative function of the present invention is functionality of e-mail clients 39 and 41 to choose and insert a correct “from” or “reply to” addresses in the agent's e-mail reply to the original e-mail sent in to the center by the customer, or at least to allow the agent to select alternative addresses.
[0029] In a multi-tenant center such as center 9 wherein customers send e-mails to multiple companies that may represented by single agents it is typically not necessary to be able to select “send to” addresses when the agent sends a reply. The e-mail client simply sends the reply to the author, as is usual. However, in the event that there are two or more companies represented by a single agent, an original message from a customer will arrive at e-mail server 23 with the message addressed to a particular company.
[0030] The most basic embodiment of the present invention is for the situation of a multi-tenant call center wherein agents may represent and answer e-mails for multiple companies. In this situation it is necessary that an agent be capable of at least manually entering, in a reply to a received e-mail, a “from” and “reply-to” address for the company to which an e-mail he or she answers was originally sent. Therefore, in an embodiment of the invention clients 39 and 41 are enabled to offer an agent, in the process of replying to an e-mail, alternative addresses for insertion in a reply, and alternative addresses for entering into new e-mails he or she may send out for one of the companies represented. The alternatives are stored in a lookup table, such as tables 33 , accessible to the agent through the client, and may be presented to the agent in any of a number of forms as known in the art, such as a menu list selectable by a cursor by “point-and-click techniques. Such a table may be at the agents computer or accessible over the LAN connection at, for example, the stat-server or in database 35 .
[0031] In an alternative embodiment the e-mail client application may automatically make selections from a look-up table 33 according to preprogrammed rules, according to the “send-to” address (for example) in the originally-received e-mail. For example, a parser (part of the module) is utilized to retrieve the “send-to” address, or even other attributes in the received e-mail, such as certain words or phrases in the body of the message. The identifier could be a special code or an order number. The client may use the order number to match that e-mail to the correct company via lookup table 33 which contains, at least, the company's names, e-mail addresses and product-order numbers. The client software may then automatically substitute the appropriate addresses automatically without the agent's concerted attention.
[0032] It will be apparent to one with skill in the art that the method and apparatus of the present invention may be practiced in an e-mail processing center connected to a CTI call center, a DNT center, or by users simply connected to a network such as the Internet without departing from the spirit and scope of the present invention. Certain aspects of the client application may be shared such as a parser and a database containing company addresses and perhaps additional information. Those same aspects may, in some embodiments, be contained within the client application on a user's computer. There are many possibilities within the spirit and scope of the invention.
[0033] It will also be apparent to one with skill in the art that the unique functions of the present invention may be performed more than once during the processing of an e-mail without departing from the spirit and scope of the present invention. For example, a general client application could reside in e-mail server 23 wherein as instructed via routing decisions, inserts the appropriate e-mail address to a connected agent at his or her computer, such as computer 21 for example.
[0034] In an alternative embodiment the system of the invention can enable an agent to forward e-mails automatically to alternative call centers or other companies. Perhaps a received e-mail message is requesting a service that is better provided by a second company to which the first company has an agreement. In this case the “send-to” address on the original message may be changed to a new address of the second company and routed to an agent representing the second company. If it is agreed by the second company that it remain anonymous, perhaps being paid for the service by the first company, then the reply message will use the “from” address of the first company to which the original message was sent, and so on.
[0035] This alternative embodiment enables several companies to perform parts of a service such as a complex manufacturing of a product without the customer knowing or being concerned about all of the different companies involved, while at the same time, the customer may receive information directly from agents representing the various companies. This saves time for both the agent representing the first company and the customer who sent the e-mail to that company.
[0036] In still another embodiment, the present invention may be practiced without center 9 . For example, companies A, B, and C may be required to complete an order for machined parts that was placed by a customer to a company D represented by an agent working at home and advertising on the Internet. Company D receives the original e-mail including a purchase order, however none of the work is actually performed by company D. Through negotiated contract, companies A, B, and C actually complete the order in stages for company D who pays them directly for each part of manufacture or service.
[0037] In current art, if a customer sends a second e-mail to company D requesting status while the parts are at the location of company A, then company D, without the aid of the present invention, would have to forward the reply to company A via e-mail, telephone, or some other media. Company D would then have to wait for a reply, then get back to the customer.
[0038] With the aid of a multi-addressable e-mail client according to the present invention, the agent representing company D may in effect substitute company A's address in the “mail-to” field of the customers e-mail request, and send it to company A as an original message from the customer. Company A would answer the e-mail and replace it's address in the “from” field with company D's address and send the reply back to the customer as an original reply. Thus, the agent at company D does not have to reply or become engaged in chasing down answers from various companies. This allows an agent to spend more time on marketing and less time on servicing.
[0039] There is another situation wherein the multi-addressability of an e-mail client as in embodiments of the present invention is very useful. This is the situation where a home agent may be enabled and connected to more than one call center, each center hosted by a different company. This agent will need the functionality of an e-mail client according to one or more embodiments of the present invention, in order to operate as though he/she is an agent of each of the call centers serviced.
[0040] [0040]FIG. 2 is a flow chart illustrating steps taken in practicing an embodiment of the present invention. The example provided herein is meant only to show one of many variant workflow possibilities pertaining to the multi-addressable client of the present invention. Other possibilities may be inherent in other embodiments. In step 43 , an agent receives an e-mail routed to him based on existing routing rules within e-mail center 9 of FIG. 1. Downloading may be automatic or initiated by the agent.
[0041] The agent begins answering the e-mail in step 45 . In step 47 the agent's e-mail client decides if the reply requires an address change. This process may be initiated when the agent chooses the “reply-to” option in his client. In the event that the agent's client handles personal mail as well as company mail, the personal mail would use the client's default settings with respect to the agent's e-mail address. The determination may be made on the simple criteria of the “send-to” address of the received e-mail, or by some other data or attribute of the received e-mail.
[0042] Having determined in step 47 that the particular e-mail the agent is answering requires intervention, the client immediately looks up the correct company address or addresses in step 49 . This step takes place automatically in a preferred embodiment while the agent is formulating and typing his response. Additional information may also be accessed in this step such as information regarding the status of an order, changes or revisions to order status, or other information.
[0043] In step 51 the client inserts the correct company address or addresses into the appropriate field or fields in the agent's reply. Also, other information retrieved in step 49 that may be pertinent to a customer's order could be presented to an agent in a separate dialogue box and may help the agent in formulating a response. In step 53 , the agent sends the completed reply to the customer.
[0044] In an alternative embodiment steps 47 may be at the agent's discretion, and the client may present the agent with alternative addresses for insertion, or allow the agent to simply enter in variable fields in the reply form, alternative addresses.
[0045] It will be apparent to one with skill in the art that the steps described immediately above may be different for use with alternate embodiments of the present invention. It will also be apparent to one with skill in the art that the multi-addressable capability, as described herein, could be provided as a complete e-mail software program or, incorporated into existing applications as an upgrade without departing from the spirit and scope of the present invention.
[0046] It will be appreciated by the skilled artisan that there are many alternatives to the embodiments described within the spirit and scope of the invention. There are many ways, for example that alternative data may be presented to an agent or other user. There are many alternatives in ways software routines may be written while accomplishing the unique functionality of the present invention. There are similarly many other alternatives within the scope of the invention. The spirit and scope of the present invention is limited only by the claims that follow. | An e-mail processing application executable on a computer station having a video display unit (VDU) searches a received e-mail for one or more words, phrases, and addresses for comparison with stored words, phrases and addresses in a stored table, and upon finding a match in the stored table, inserts one or more of words, phrases, or addresses associated in the stored table with the words, phrases or addresses from the received e-mail in any reply to the received e-mail. In a preferred embodiment a “send to” address in a received e-mail triggers automatically one or both of a particular “from” and “reply to” address in any response to the received e-mail. In an alternative embodiment, a “send to” address in a received e-mail, as a result of a table look-up, automatically prepares and sends a new e-mail identical to the received e-mail except for a new “send to” address retrieved from the stored table. In alternative embodiments the application simply provides variable fields in a reply window for a user to enter variable “from” and “reply to” addresses. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to a snow removal apparatus. More particularly, the present invention relates to a snow removal apparatus for removing snow from train tracks.
BACKGROUND OF THE INVENTION
[0002] In many climates, snow accumulates on train tracks. This snow impedes the ability of trains to move along the train tracks. When only a relatively small amount of snow has accumulated on the train tracks, it is possible to remove the snow from the train tracks with a plow. As the level of snow increases, it becomes impossible for the train to have sufficient power to push the snow off the train tracks with the plow.
[0003] To overcome this limitation and enable trains to continue operating, two-stage snow blowers have been attached to the front of trains. The first stage collects the snow and the second stage propels the snow away from the train tracks. The snow blower extends across the width of the train and thereby enables the snow to be cleared from the train tracks.
[0004] Examples of two-stage snow removal devices are found in Schmidt, U.S. Pat. No. 4,151,663; Schmidt, U.S. Pat. No. 4,354,320; and Gruber, U.S. Pat. No. 4,829,684.
SUMMARY OF THE INVENTION
[0005] The present invention is a snow removal apparatus for removing snow from train tracks that includes a first snow blowing device and a second snow blowing device. The first snow blower element is mounted to a front portion of a train car to clear snow from in front of the train car. The second snow blowing device is operably connected to the train car so that the second snow blowing device can clear snow from a region that is adjacent to the train car.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a side view of a snow removal apparatus according to the present invention.
[0007] [0007]FIG. 2 is a top view of the snow removal apparatus with a second snow removal apparatus in a retracted position.
[0008] [0008]FIG. 3 is a top view of the snow removal apparatus with the second snow removal apparatus in an extended position.
[0009] [0009]FIG. 4 is a side view of the snow removal apparatus with the second snow removal apparatus in an extended position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] The present invention is a snow removal apparatus as most clearly illustrated at 10 in FIG. 1. The snow removal apparatus 10 generally includes at least one train car 20 , a first snow removal apparatus 22 and a second snow removal apparatus 24 . The first and second snow removal apparatus 22 , 24 are mounted to the at least one train car 20 to clear snow from a width that is considerably wider than the width of the at least one train car 20 .
[0011] The snow removal apparatus 10 of the present invention thereby provides the ability to clear snow from a path that is wider than the train. The snow removal apparatus 10 thereby reduces the time needed to remove snow from train tracks. The snow removal apparatus 10 also minimizes the potential that snow will be swept back over the train tracks after the train passes over the train tracks, which thereby reduces the frequency that the snow removal device 10 must be used on a specified length of train track.
[0012] The at least one train car 20 preferably includes a first train car 20 a and a second train car 20 b. The at least one train car 20 may also include a third train car 20 c, which provides an enclosed region for persons operating the snow blowing apparatus 10 to rest, such as a conventional caboose. Each of the train cars 20 a, 20 b have a frame and a plurality of wheels rotatably mounted to the frame.
[0013] The first train car 20 a preferably includes a motor (not shown) that enables the snow removal apparatus 10 to move along the train tracks under its own power. A person of ordinary skill in the art will appreciate that it is also possible to use the snow removal apparatus 10 with a conventional locomotive or other powered rail cars (not shown).
[0014] The first snow blowing device 22 is preferably attached to the front of the first train car 20 a. The first snow blowing device 22 preferably includes a two-stage configuration with a first stage that collects snow and conveys the snow to a second stage. The second stage conveys or blows the snow away from the train. A person of ordinary skill in the art will appreciate that a variety of snow blowing devices can be used with the concepts of the present invention.
[0015] The second snow blowing device 24 is preferably mounted to the second train car 20 b with an arm 30 . The arm 30 may include a structure that merely supports the second snow blowing device 24 . Alternatively, the arm 30 may include the ability to convey snow away from the second snow blowing device 24 . In this configuration, the arm 30 preferably has a structure that is similar to the arms used with railroad-mounted trench diggers, such as is disclosed in U.S. Pat. No. 4,713,898, which is assigned to the assignee of the present application, the disclosure of which is hereby incorporated by reference.
[0016] The arm 30 has a first arm portion 32 and a second arm portion 34 . The first arm portion 32 and the second arm portion 34 intersect proximate to a pivot axis 36 at which the arm 30 is pivotally attached to the second train car 20 b, as most clearly illustrated in FIG. 4. The first arm portion 32 is also vertically pivotable to raise and lower the height of the second snow blowing device 24 , as most clearly illustrated in FIG. 3. A person of ordinary skill in the art will appreciate that a variety of techniques may be used to control the rotation and pivoting of the arm 30 .
[0017] The second snow blowing device 24 is pivotally attached to the arm 30 so that the second snow blowing device 24 can be rotated horizontally and vertically with respect to the arm 30 . Movement in these directions enables the second snow blowing device 24 to be oriented towards the front of the snow removal apparatus 10 at various angular orientations of the arm 30 with respect to the second train car 20 b.
[0018] The second snow blowing device 24 may have a configuration that is substantially similar to the configuration of the first snow blowing device 22 , which includes a conventional two-stage snow blower where the first stage collects and conveys the snow to a second stage. The second stage propels or blows the snow away from the snow blower.
[0019] While not necessary, wheels or other similar devices may be mounted on the second snow blowing device 24 to support a portion of the weight of the second snow blowing device 24 . For example, the wheels may be configured to roll along train tracks that are adjacent to train tracks upon which the snow removal apparatus 10 is located.
[0020] Alternatively, the second snow blowing device 24 is operably connected to a conveying system that is included in typical ditcher devices. Snow would then be collected with the second snow blower element 24 and then conveyed along the first arm portion 32 and the second arm portion before being discharged from the snow removal apparatus 10 .
[0021] In operation, the snow removal apparatus 10 is moved under its own power to a location where snow has accumulated on train tracks in a retracted configuration, as illustrated in FIG. 1. The first snow blowing device 22 is activated to begin clearing snow from the train tracks. Next, the arm 30 is rotated so that the second snow blower element 24 is positioned adjacent to the second rail car 20 b, as illustrated in FIG. 4. The arm 30 is then raised or lowered so that the second snow blowing device 24 is positioned proximate a ground surface. The second snow blowing device 24 is then activated to begin clearing snow from a region adjacent the train tracks or from a second set of train tracks that are located in proximity to the first train tracks.
[0022] The snow removal apparatus 10 is then moved along the train track as the first snow blowing device 22 and the second snow blowing device 24 are operating to clear snow. By using the snow removal apparatus of the present invention, the time it takes to clear snow from train tracks is greatly reduced when compared with snow removal devices that are only able to clear snow from a single set of train tracks.
[0023] The concepts of the present invention are also suited for use in applications other than trains. For example, the snow removal apparatus can be used with wheeled or track-mounted vehicles.
[0024] The concepts of the present invention are further suited for use with alternative snow removal mechanisms such as snow plows.
[0025] It is contemplated that features disclosed in this application, as well as those described in the above applications incorporated by reference, can be mixed and | A snow removal apparatus having a frame, a first snow removal device, and a second snow removal device. The first snow removal device is operably mounted to the frame for removing snow from a front end of the frame. The second snow removal device is operably mounted to the frame for removing snow from a region lateral to a front end of the frame. The first snow removal device and the second snow removal device enable snow to be removed from a width that is wider than a width of the frame. | 4 |
RELATED APPLICATION(S)
[0001] This application is a Continuation application of U.S. patent application Ser. No. 12/011,029, filed on Jan. 23, 2008, which claims the benefit of U.S. Provisional Application No. 60/881,967, filed on Jan. 23, 2007. The entire teachings of the above application(s) are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] In charge-domain signal-processing circuits, signals are represented as charge packets. These charge packets are stored, transferred from one storage location to another, and otherwise processed to carry out specific signal-processing functions. Charge packets are capable of representing analog quantities, with the charge-packet size in coulombs being proportional to the signal represented. Charge-domain operations such as charge-transfer are driven by ‘clock’ voltages, providing discrete-time processing. Thus, charge-domain circuits provide analog, discrete-time signal-processing capability. This capability is well-suited to performing analog-to-digital conversion using pipeline algorithms.
[0003] Charge-domain circuits are implemented as charge-coupled devices (CCDs), as MOS bucket-brigade devices (BBDs), and as bipolar BBDs. The present invention pertains to MOS BBDs.
[0004] Pipelined analog-to-digital converters (ADCs) are well-known in the general field of ADC design. They are widely used in applications in which high sample rates and high resolution must be combined. Pipelined ADCs implement the well-known successive-approximation analog-to-digital (A/D) conversion algorithm, in which progressively-refined estimates of an input signal are made at sequential times. In pipelined versions of this algorithm, one or several bits are resolved at each pipeline stage, the quantized estimate is subtracted from the signal, and the residue is propagated to the next pipeline stage for further processing. Pipelined ADCs have been implemented using a variety of circuit techniques, including switched-capacitor circuits and charge-domain circuits. The present invention pertains to charge-domain pipelined ADCs employing MOS BBDs.
SUMMARY OF THE INVENTION
[0005] In BBD-based pipelined ADCs, the gain between pipeline stages is nominally unity: that is, all net charge present in each stage ideally is transferred to the next stage. In practical BBD-based circuits, however, the charge-transfer gain is less than unity, resulting in errors in the A/D conversion process. Moreover, in all pipelined ADCs including those employing BBDs, mismatch of capacitors and of capacitor ratios causes such errors.
[0006] The present invention corrects for errors in BBD-based pipelined ADCs due to both capacitor mismatch and to sub-unity charge-transfer gain. Circuits that implement this correction are compact and temperature-stable, and consume low power.
[0007] In a preferred embodiment, a pipelined charge domain circuit using bucket brigade charge transfer comprises a first charge transfer circuit; a second charge transfer circuit; and a node coupled to the first charge transfer circuit and the second charge transfer circuit. A clocked capacitor is coupled to the node and to a clocked voltage. Furthermore, a conditionally-switched capacitor is also coupled to the node, with the conditionally-switched capacitor driven by a transition voltage. An adjustment circuit is provided for adjusting the transition voltage according to conditions detected within the pipelined charge domain circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
[0009] FIG. 1 shows a simplified circuit diagram of a BBD charge-pipeline stage.
[0010] FIG. 2 illustrates voltage waveforms associated with FIG. 1 .
[0011] FIG. 3 shows a BBD charge-pipeline stage including conditional charge addition.
[0012] FIG. 4 illustrates voltage waveforms associated with FIG. 3 .
[0013] FIG. 5 shows a BBD charge-pipeline stage including conditional charge addition, with the added charge composed of two independent components.
[0014] FIG. 6 shows a two-stage pipeline segment composed of stages like that of FIG. 3 .
[0015] FIG. 7 shows a circuit diagram of a capacitor driver with an adjustable voltage transition.
[0016] FIG. 8 illustrates voltage waveforms associated with FIG. 7 .
[0017] FIG. 9 shows a circuit diagram of a replica-based circuit for determining a charge-transfer voltage-feedback coefficient.
[0018] FIG. 10 illustrates voltage waveforms associated with FIG. 9 .
[0019] FIG. 11 shows the adjustment circuit connected to a pipeline stage.
[0020] FIG. 12 is a more detailed view of a differential BBD-charge pipeline stage.
DETAILED DESCRIPTION OF THE INVENTION
[0021] A description of example embodiments of the invention follows.
[0022] The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety.
[0023] In the following description, all circuits are discussed assuming electrons as the signal-charge carriers and NFETs for signal-charge transfer. Functionally equivalent circuits can be applied equally well using holes as charge carriers, by employing PFETs and reversed signal and control voltage polarities. In the discussion and figures, charge-transfer circuits are represented abstractly and the relevant behavioral aspects of these circuits are described, but in some instances, specific details of the operation of such circuits are understood by those of skill in the art and/or are not relevant to the invention claimed herein, and thus are not provided. The issue of sub-unity charge transfer gain is common to all known charge-transfer circuits.
[0024] The basic principle of a BBD pipeline of the general type employed in a preferred embodiment of this invention is described with the aid of FIG. 1 , which depicts a single stage of such a pipeline. In this stage charge is stored on capacitor 5 , which is connected between storage node 2 and voltage V C1 . Charge enters the stage via charge-transfer circuit 1 , and later exits the stage via charge-transfer circuit 3 . Voltage V C1 is a digital clock signal which controls the timing of charge processing in the stage. Other digital clock signals, not shown, may be used to control the activity of the charge-transfer circuits.
[0025] Operating waveforms of the pipeline stage are shown in FIG. 2 . At time to clock voltage V C1 has a positive value 25 . V 2 , the voltage of storage-node 2 in FIG. 1 , is also at a high initial voltage 21 . At t 1 negative charge begins to be transferred from the previous stage (to the left of FIG. 1 ) via charge-transfer circuit 1 into the stage shown. As this negative charge accumulates on capacitor 5 , V 2 falls to a more negative value. The voltage of node 2 settles to a relatively high value 22 A if a relatively small negative charge was transferred; with a larger charge transferred, node 2 settles to a more negative voltage 22 B. At time t 2 charge transfer into the stage is complete. The voltage of node 2 is related to the charge by the well-known expression Q=CV, where C is the total capacitance of node 2 . In FIG. 1 , C is comprised of C 5 , the capacitance of capacitor 5 , plus any parasitic capacitance of node 2 ; such parasitic capacitance is usually small and is neglected in this discussion.
[0026] Charge transfer out of the stage begins at time t 3 when clock voltage V C1 switches to a low state. Capacitor 5 couples this voltage transition to node 2 , driving V 2 low as well. Charge-transfer circuit 3 absorbs charge from capacitor 5 , limiting the negative excursion of node 2 , and eventually causing node 2 to settle to voltage 23 at t 4 . Voltage 23 is a characteristic of charge-transfer circuit 3 , and is independent of the amount of charge which had been stored on node 2 . Charge-transfer circuit 3 transfers the charge absorbed from capacitor 5 to node 4 which is part of the stage following the one shown. After t 4 charge transfer is complete.
[0027] Finally, at time t 5 , clock voltage V C1 returns to its initial state (voltage 25 ). Its positive-going transition is coupled to node 2 by capacitor 5 , raising node 2 to voltage 24 . Neglecting parasitic capacitance, no charge flows onto or off of node 2 during this transition; the voltage change of V 2 is therefore equal to the voltage change of V C1 during the transition at t 5 . Since V 2 's value at the start of this transition, voltage 23 , is independent of charge processed, voltage 24 is likewise independent of charge processed. This transition completes the operating cycle; the resulting voltage 24 at node 2 is thus the initial voltage for the next cycle. Thus the initial voltage state of the stage is constant cycle-to-cycle, and voltage 21 =voltage 24 . Consequently the initial and final charge on node 2 are also equal, and the charge transferred out is equal to the charge transferred in.
[0028] In summary: charge is transferred into the stage shown in FIG. 1 during t 1 -t 2 ; between times t 2 and t 3 it is temporarily stored on capacitor 5 , and is manifested as the value of V 2 ; during times t 3 -t 4 this charge is completely transferred to the next stage; at t 5 the stage returns to its initial state, ready again to receive incoming charge. Thus the basic stage shown acts as a shift register for analog charge packets.
[0029] The foregoing description is somewhat idealized; it should be understood that practical circuits depart in many details from this description. Such departures include non-zero parasitic capacitance and imperfect charge transfer, for example. These effects, however, do not change the basic operating principles described above. Certain details of circuit operation, such as clocking of the charge-transfer circuits, are also omitted, as they are not pertinent to the present invention.
[0030] In order to form a charge-domain ADC from a pipeline composed of stages similar to FIG. 1 , a minimum of two operations in addition to charge storage and shifting are required: charges must be compared to a reference value, typically another charge; and a reference charge must be conditionally added to the signal charge (this ‘addition’ may be of either sign). In a previous patent application by the same inventor entitled “Charge-Domain Pipelined Analog-to-Digital Converter” filed on Jan. 18, 2008 and given Ser. No. 12/009,615, Attorney Docket Number 3575.1028-002, which itself claims priority an earlier filed provisional application of the same title filed on Jan. 19, 2007 and given provisional application Ser. No. 60/881,392, both of which are hereby incorporated by reference in their entirety, an ADC is disclosed which implements pipelined successive-approximation ADC algorithms using these operations. The present invention provides a way to improve the accuracy of charge-transfer and conditional-charge addition in such an ADC. For purposes of understanding the present invention, the charge-comparison aspects of ADC implementation are not important, and are not discussed further. Conditional charge addition is essential for such understanding, however, and is explained with reference to FIGS. 3 and 4 below.
[0031] The basic principle employed for conditional charge addition is depicted in FIG. 3 , with operating waveforms shown in FIG. 4 . For the purposes of this discussion, a single-ended stage is shown. In practical ADC designs, differential operation is usually preferred; the present invention is applicable to both single-ended and differential pipeline circuits. More details of the implementation of a differential pipeline stage are shown and described in the aforementioned “Charge-Domain Pipelined Analog-to-Digital Converter” patent application.
[0032] The pipeline stage shown in FIG. 3 retains all the elements shown in FIG. 1 . In addition, FIG. 3 includes two new elements: capacitor 6 (with value C 6 ) connected between charge-storage node 2 and voltage V QR1 ; and switch 7 connected between node 2 and voltage V P . Switch 7 is controlled by a periodic digital clock signal (identified as S 7 in FIG. 4 ).
[0033] FIG. 4 shows the operating waveforms of the circuit of FIG. 3 . The initial conditions in FIG. 4 are similar to those in FIG. 2 : V C1 is at high voltage 45 and V 2 , the voltage of node 2 , is at high voltage 41 . In addition, V QR1 is at high voltage 47 , and switch 7 is in an off state, indicated by the low value of its control signal S 7 in FIG. 4 . As in FIG. 2 , charge is transferred into the stage between t 1 and t 2 , causing V 2 to fall in proportion to the incoming charge, settling at voltage 42 . The change in V 2 due to incoming charge is inversely proportional to the total capacitance of node 2 as explained above. In FIG. 3 (neglecting parasitic capacitance) this total capacitance is C=C 5 +C 6 .
[0034] After the charge is transferred in, the new features of FIG. 3 come into play. At time t 3A voltage V QR1 conditionally switches from its high state 47 to low state 48 . This conditional transition of V QR1 is coupled via C 6 to node 2 where, because of capacitive division, it produces a similar but smaller voltage change. The voltage at node 2 changes to voltage 49 (dashed line) if V QR1 switches, and remains at voltage 42 (solid line) if it does not.
[0035] At time t 3 , V C1 switches from high voltage 45 to low voltage 46 , instigating charge transfer out of the stage. As explained with reference to FIG. 2 , node 2 is driven to a lower voltage due to coupling via capacitor 5 . Charge-transfer circuit 3 removes charge from node 2 and transfers it to the next stage. By t 4 V 2 settles to voltage 43 which is independent of the charge previously on node 2 , and charge transfer out of the stage is complete.
[0036] At t 5 both V C1 and V QR1 return to their initial high states (voltages 45 and 47 respectively). This transition is identical for V C1 in every clock cycle. V QR1 , however, may already be at its high voltage 47 , depending on whether or not it switched at t 3A . Thus the positive step coupled to node 2 at t 5 can have different values, depending on the state of V QR1 , resulting in a different final voltage. The added switch 7 in FIG. 3 is used to restore the voltage (and charge) on node 2 to a repeatable state regardless of the state of V QR1 at t 5 . Switch 7 is turned on, as indicated by the high state of its control signal S 7 , during t 5 -t 6 , thus establishing a repeatable voltage at node 2 to begin the next cycle, so voltage 44 =voltage 41 . With an ideal switch, voltage 44 =V P ; practical MOS switches introduce a small ‘pedestal’ so that voltage 44 ≠V P . This non-ideality is, however, repeatable cycle-to-cycle, so the voltage 44 =voltage 41 condition is still met in practical circuits.
[0037] Unlike the case of FIG. 1 where the charge transferred into the stage was subsequently transferred out without alteration, the outgoing charge in the circuit of FIG. 3 differs in general from the incoming charge:
[0000] Q OUT =Q IN +C 6 ΔV QR1 +Q CONST Equation 1
[0000] where C 6 is the capacitance of capacitor 6 , ΔV QR1 is the change in V QR1 at t 3A , and Q CONST is given by:
[0000] Q CONST =( C 5 +C 6 )(voltage 41−voltage 43)+ C 5 (voltage 46−voltage 45) Equation 1A
[0038] Q CONST is nominally a fixed charge, since voltages 41 , 43 , 45 , and 46 are all ideally constant. Departures from this ideal case, which constitute one source of charge-transfer imperfection, will be discussed below.
[0039] As is apparent in FIG. 4 , ΔV QR1 is equal to (voltage 48 −voltage 47 ) if V QR1 switches, and is equal to zero if it does not. Note that both charge quantities C 6 ΔV QR1 and Q CONST can be made either positive or negative by appropriate choices of the various voltages.
[0040] When the circuit of FIG. 3 is used to form one stage of a pipelined ADC, the quantity (voltage 48 −voltage 47 ) is made equal to a reference voltage; for convenience it will be called V R1 . Correspondingly, the quantity C 6 V R1 becomes a reference charge, since C 6 is fixed in a given instantiation. Thus the conditional choice of ΔV QR1 =V R1 or ΔV QR1 =0 at t 3A corresponds in Equation 1 to the conditional addition of a reference charge C 6 V R1 to the incoming charge packet Q IN . The circuit of FIG. 3 thus provides one of the two operations required for a charge-domain ADC implementation.
[0041] Note that the exact position of time t 3A is not critical to the operation of the circuit of FIG. 3 . The conditional transition of V QR1 can occur at any time between t 0 and t 3 with no change in circuit performance; under some practicable conditions it may also occur in the t 3 -t 4 interval.
[0042] In some ADC implementations it is desirable to provide more than one conditional charge addition in a single pipeline stage. An example of such a stage is shown in FIG. 5 . This circuit includes, in addition to the elements in FIG. 3 , additional capacitor 6 A and voltage source V QR2 . The operation of such a stage is identical to that of FIG. 3 , except that at t 3A each of the voltages V QR1 and V QR2 undergoes an independent conditional transition, of size V R1 and V R2 (or zero) respectively. The resulting charge transfer function of the stage is given by:
[0000] Q OUT =Q IN +C 6 ΔV QR1 +C 6A ΔV QR2 +Q CONST2 Equation 2
[0000] where Q CONST2 is given by:
[0000] Q CONST2 =( C 5 +C 6 +C 6A )(voltage 41−voltage 43)+ C 5 (voltage 46−voltage 45) Equation 2A
[0043] The same principle can be extended to any number of capacitors and V R values. For simplicity Equations 1 and 1A will be used as the basis for the following discussion. The principles described are equally applicable to circuits with more than one conditionally-switched capacitor, as in FIG. 5 .
[0044] Two idealizations included in the discussion above are, in general, imperfectly realized in practical circuits: first, because of tolerances in manufacturing, conditionally-switched capacitors such as C 6 generally do not have precisely the intended values; second, the final voltage to which the floating diffusion 2 settles (voltage 43 in FIG. 4 , for example) is in general not perfectly independent of Q OUT . The effects of these non-idealities are considered in detail below, beginning with the dependence of voltage 43 on Q OUT .
[0045] Considering a first-order (linear) dependence of voltage 43 upon Q OUT , the value of voltage 43 can be written v 43 =v 43N +kQ OUT , where v 43 is the actual value of voltage 43 , v 23N is the nominal value, and k is a coefficient embodying the linear dependence on Q OUT . Using this expression for voltage 43 in Equation 1A yields:
[0000]
Q
CONST
=
(
C
5
+
C
6
)
(
voltage
41
-
v
43
N
-
k
Q
OUT
)
+
C
5
(
voltage
46
-
voltage
45
)
=
(
C
5
+
C
6
)
(
voltage
41
-
v
43
N
)
+
C
5
(
voltage
46
-
voltage
45
)
-
(
C
5
+
C
6
)
k
Q
OUT
=
Q
CC
-
(
C
5
+
C
6
)
k
Q
OUT
Equation
3
[0000] where Q CC is the Q OUT -independent (i.e., constant) component of Q CONST . Replacing Q CONST in Equation 1 with the expression given by Equation 3, we obtain:
[0000] Q OUT =Q IN +C 6 ΔV QR1 +Q CC −( C 5 +C 6 ) kQ OUT Equation 4
[0046] Turning now to the fabrication errors in C 6 , we can write C 6 =C 6N +C 6E , where C 6N is the nominal value of C 6 , and C 6E is the deviation from nominal. Substituting this expression into Equation 4 yields:
[0000] Q OUT =Q IN +C 6N ΔV QR1 +C 6E ΔV QR1 +Q CC −( C 5 +C 6 ) kQ OUT Equation 5
[0047] In fractional terms, the errors expressed in Equation 5 are C 6E /C 6N and (C 5 +C 6 )k, both of which are dimensionless quantities. In practical designs these fractional errors are small (i.e., <<1). Thus we can find a practically-useful approximation to Equation 5 by replacing Q OUT in the last term with the full expression given by Equation 5, and then omitting second-order error effects (i.e., terms including squares or products of the fractional errors). Defining ε=(C 5 +C 6 )k and carrying out this procedure, we obtain:
[0000] Q OUT =Q IN (1−ε)+ C 6N ΔV QR1 (1−ε)+ Q CC (1−ε)+ C 6E ΔV QR1 Equation 6
[0048] Comparing this expression to the idealized expression of Equation 1, it is apparent that the quantity (1−ε) is an effective charge-transfer gain; ε is the amount by which that gain falls short of unity. The term C 6E ΔV QR1 embodies the effect of fabrication error in C 6 .
[0049] A pipelined charge-domain ADC is composed of multiple stages like that of FIG. 3 , in which reference charges are conditionally added and subsequently transferred down the pipeline. (As mentioned above, some architectures employ multiple conditional charges per stage.) Equation 6 expresses the output charge of each such stage in terms of that stage's input charge and its conditional capacitor switching. At any stage of the pipeline, the input charge is the sum of the signal-charge input to the pipeline and the cumulative changes due to up-stream pipeline stages according to Equation 6.
[0050] Consider for example the two-stage pipeline segment shown in FIG. 6 , which is composed of stages like that in FIG. 3 . The two stages, 61 and 62 , each consist of a storage node ( 67 and 68 respectively), a charge-transfer circuit ( 65 and 66 respectively), a conditionally-switched capacitor ( 63 and 64 respectively), a clocked capacitor ( 601 and 602 ), and a precharge switch V P . The input charge to the pipeline segment, Q PIN , is supplied to storage node 67 of stage 61 as indicated. The output of this pipeline segment (which is the output charge of stage 62 ) appears at node 69 . The conditionally-switched voltages driving capacitors 63 and 64 are V QR1 and V QR2 respectively. They can each independently be switched, with a step-size of 0 or V R1 and 0 or V R2 respectively, where V R1 and V R2 are reference voltages.
[0051] Such a pipeline operates in two-phases: alternating stages operate on alternating half-cycles of the clock. In the circuit of FIG. 6 , for example, charge is transferred into stage 61 and out of stage 62 on the first half-cycle, and is transferred out of stage 61 and into stage 62 on the second half-cycle. Details of this clocking method are not germane to the subject of the present invention, and are not treated further.
[0052] The input charge to stage 62 in FIG. 6 is the output charge from stage 61 . Thus, with the input charge to stage 61 equal to Q PIN , the output charge from stage 62 can be derived by applying Equation 6 twice:
[0000]
Q
OUT
62
=
Q
IN
62
(
1
-
ɛ
)
+
C
64
N
Δ
V
QR
2
(
1
-
ɛ
)
+
Q
CC
(
1
-
ɛ
)
+
C
64
E
Δ
V
QR
2
=
[
Q
PIN
(
1
-
ɛ
)
+
C
63
N
Δ
V
QR
1
(
1
-
ɛ
)
+
Q
CC
(
1
-
ɛ
)
+
C
63
E
Δ
V
QR
1
]
(
1
-
ɛ
)
+
C
64
N
Δ
V
QR
2
(
1
-
ɛ
)
+
Q
CC
(
1
-
ɛ
)
+
C
64
E
Δ
V
QR
2
=
Q
PIN
(
1
-
ɛ
)
2
+
C
63
N
Δ
V
QR
1
(
1
-
ɛ
)
2
+
C
64
N
Δ
V
QR
2
(
1
-
ɛ
)
+
C
63
E
Δ
V
QR
1
(
1
-
ɛ
)
+
C
64
E
Δ
V
QR
2
+
[
(
1
-
ɛ
)
2
+
(
1
-
ɛ
)
]
Q
CC
Equation
7
[0053] This expression can be simplified by omitting second-order error terms as was done above, giving:
[0000]
Q
OUT
62
=
Q
PIN
(
1
-
2
ɛ
)
+
C
63
N
Δ
V
QR
1
(
1
-
2
ɛ
)
+
C
64
N
Δ
V
QR
2
(
1
-
ɛ
)
+
C
63
E
Δ
V
QR
1
+
C
64
E
Δ
V
QR
2
+
(
2
-
3
ɛ
)
Q
CC
Equation
8
[0054] Equation 8 shows the cumulative effect of charge-transfer gain and capacitor errors in a two-stage pipeline. The same analysis can be extended to multiple stages and to multiple conditionally-switched capacitors per stage.
[0055] In order for a pipelined charge-domain ADC to produce linear results, it is essential that the conditionally-added charges from each stage appear at the end of the ADC pipeline with a specific ratio. In the Equation 8 the (non-zero) values of the conditionally-added charges are nominally C 63N V R1 and C 64N V R2 in the first and second stages respectively. According to equation 8 then, the conditionally-added charge values, as they appear at the pipeline output, are:
[0000] [C 63N V R1 (1−2ε)+C 63E V R1 ] from the first stage, and
[C 64N V R2 (1−ε)+C 64E V R2 ] from the second stage.
[0056] Thus the ADC linearity requirement can be expressed as:
[0000] [ C 63N V R1 (1−2ε)+ C 63E V R1 ]/[C 64N V R2 (1−ε)+ C 64E V R2 ]=K Equation 9
[0000] where K is the intended ratio. In an ideal pipeline segment, in which the charge-transfer and capacitor errors are zero, Equation 9 is simplified to:
[0000] ( C 63N V R1 )/( C 64N V R2 )= K Equation 10
[0057] The effects of non-zero gain error ε and capacitor errors such as C 63E are evident when Equation 9 is compared to Equation 10.
[0058] One aspect of the present invention provides a way to satisfy Equation 9 when these errors have non-zero values. This can consist of providing an adjustment to the reference voltages V R1 and V R2 . The nominal capacitance values C 63N and C 64N and the reference voltages V R1 and V R2 are chosen to satisfy Equation 10; then independently adjustable voltages V A1 and V A2 are added to V R1 and V R2 . With this change, and again omitting second-order error terms, the upper and lower terms in the ratio of Equation 9 become:
[0000]
[
C
63
N
V
R
1
(
1
-
2
ɛ
)
+
C
63
E
V
R
1
]
→
[
C
63
N
(
V
R
1
+
V
A
1
)
(
1
-
2
ɛ
)
+
C
63
E
V
R
1
]
=
[
C
63
N
V
R
1
(
1
-
ɛ
)
-
ɛ
C
63
N
V
R
1
+
C
63
E
V
R
1
+
C
63
N
V
A
1
]
and
[
C
64
N
V
R
2
(
1
-
ɛ
)
+
C
64
E
V
R
2
]
→
[
C
64
N
(
V
R
2
+
V
A
2
)
(
1
-
ɛ
)
+
C
64
E
V
R
2
]
=
[
C
64
N
V
R
2
(
1
-
ɛ
)
+
C
64
E
V
R
2
+
C
64
N
V
A
2
)
]
[0059] The added voltages are now adjusted to force the ratio of the adjusted bracketed terms to equal K. For example, setting:
[0000] V A1 =[ε−( C 63E /C 63N )] V R1 Equation 11A
[0000] and
[0000] V A2 =−( C 64E /C 64N ) V R2 Equation 11B
[0000] results in the desired ratio. With this solution, V A2 is adjusted to correct for the error of capacitor 64 and V A1 is adjusted to compensate both for the error of capacitor 63 and for the charge-transfer gain ε.
[0060] An alternative adjustment is:
[0000] V A1 =( C 63E /C 63N ) V R1 Equation 12A
[0000] and
[0000] V A2 =[−ε−( C 64E /C 64N )] V R2 Equation 12B
[0000] which also results in the desired ratio. With this solution, V A1 is adjusted to correct for the error of capacitor 63 and V A2 is adjusted to compensate both for the error of capacitor 63 and for the charge-transfer gain ε. Both solutions 11A/B and 12A/B are useful. Any linear combination of these solutions can be used with the same result.
[0061] This same adjustment principle can be applied in a pipeline with any number of stages. It can also be applied in an ADC design with more than one conditionally-added charge per stage (as in the example of FIG. 5 ). In these cases, a separate adjustment voltage (V A ) is applied to the reference voltage for each conditionally-switched capacitor. With the adjustment method of Equation 12A/B, for example, each such adjustment corrects for the combination of that individual capacitor's error and the total charge-transfer errors of all previous stages. In some designs, the charge-transfer error is not identical from stage to stage, but this adjustment method intrinsically accommodates such variation.
[0062] In addition, the same adjustment principle can be applied to a differential pipeline stage; in such an instance it may be preferable to generate a single adjustment voltage V A that is shared between the two members of the differential circuit.
[0063] Recall from the discussion of FIGS. 3 and 4 that the conditional voltage transition ΔV QR1 which produces the conditional charge addition C 6 ΔV QR1 results from switching V QR1 between two fixed voltages ( 47 and 48 in FIG. 4 ). This voltage difference constitutes the reference voltage V R . A practical way of adding the adjustment voltage V A to V R is to insert a small adjustable voltage in series with either voltage 47 or voltage 48 . One realistic implementation of the driver and adjustable voltage source, 8 and 9 in FIG. 11 , is shown in FIG. 7 .
[0064] FIG. 11 shows an example of a pipeline stage like that of FIG. 1 with such an adjustment voltage added. Pipeline elements 1 , 2 , 3 , 5 , and 6 are equivalent to those in FIG. 1 . The added elements are a driver 8 for conditionally-switched capacitor 6 , and an adjustable voltage source 9 . The output of driver 8 switches between supplied voltage V 8 and the voltage at node 10 in response to a digital control signal S QR1 , thus providing the required conditional voltage transition. Thus V H and voltage 10 provide the voltages identified as 47 and 48 respectively in FIG. 4 . Adjustable voltage source 9 adjusts the low voltage supplied to capacitor 6 as described above.
[0065] FIG. 12 shows a differential pipeline with similar function. Each member of the differential pair of pipeline nodes, 2 and 122 , is provided with a conditionally-switched capacitor, 6 and 126 respectively. The voltage transitions driving capacitors 6 and 126 are provided by drivers 8 and 128 , switching between V H and the voltages of nodes 10 and 130 , in response to digital control signals S QR1A and S QR1B , respectively. The voltages of nodes 10 and 130 are supplied by adjustable voltage sources 9 and 129 respectively. Nodes 10 and 130 may be connected to form a single node, and supplied by a single adjustable source such as 9 .
[0066] FIG. 7 shows a CMOS inverter consisting of PFET 71 and NFET 72 , supplied by fixed voltages V H and V L . The NFET is connected to V L via resistor 73 at node 75 . An adjustable current 74 is also connected to node 75 . The inverter is driven by a logic signal S QR1 , and its output constitutes the voltage signal V QR1 shown in FIG. 3 .
[0067] FIG. 8 shows operating waveforms for the circuit of FIG. 7 . At time to logic signal S QR1 is at a low state, turning PFET 71 on and NFET 72 off. Voltage V QR1 is at an initial high value which is equal to V H . At time t 3A S QR1 switches to a high logic state, turning FET 71 off and FET 72 on. FET 72 thus connects the output V QR1 to node 75 . If the adjustable current 74 is set to zero, then the series combination of FET 72 and resistor 73 charges V QR1 towards V L , as indicated by voltage curve 81 in FIG. 8 . Since the load on this circuit consists only of a capacitor (capacitor 6 in FIG. 3 ), there is no DC current through FET 72 or resistor 73 , so V QR1 eventually settles to V L . Thus the voltage transition of V QR1 is V L -V H . This quantity constitutes the unadjusted reference voltage V R .
[0068] If the current source 74 is adjusted to a non-zero value I A , then the initial value of node 75 is V L +V A =V L +I A R 73 , where R 73 is the value of resistor 73 . (Note that FET 72 is initially off, so no current other than I A initially flows into resistor 73 .) When S QR1 changes state, then FET 72 turns on and connects the load capacitor to node 75 , causing V QR1 to charge downward along curve 82 . At the end of this transition, current through FET 72 falls to zero and V QR1 settles to final voltage V L +V A . Thus the voltage transition of V QR1 is V L +V A −V H =V R +V A . Adjustable current source 74 , which is easily realizable in a practical circuit, thus provides for adjusting the size of the transition in V QR1 , as required. A similar circuit in which the resistor is placed in the source of PFET 71 instead of NFET 72 is equally practical. These circuits provide the necessary adjustment of V R with low power and small circuit area consumption.
[0069] As discussed in connection with Equations 11A and 12B, the required V A values have two components: one which corrects for a capacitor error and one which corrects for charge-transfer gain error. In the circuit of FIG. 7 , the current source 74 can be made to consist of two independent sources in parallel, each controlled independently to correct for one of the errors. The combined currents sum to develop the composite V A value.
[0070] The capacitor-error component corrected by V A can be expected to be temperature-invariant because it is due primarily to geometric variation between capacitors, which occurs during circuit fabrication but does not generally change thereafter. Thus an adjustment voltage V A which tracks V R provides a temperature-stable adjustment. Creating a component of V A which tracks V R over temperature using circuits similar to FIG. 7 is straightforward in a conventional CMOS process. The value of this adjustment voltage can be set by a calibration process carried out during manufacturing test or upon powering-up the circuit, for example.
[0071] The second V A component corrects for charge-transfer gain error. This error depends on details of the charge-transfer circuits employed, and depends in general on both fabrication-process variation and on operating temperature. Known BBD charge-transfer circuits include both conventional (passive) ones and ones employing active circuitry, such as those described in a previous patent application by the same inventor entitled “Boosted Charge-Transfer Pipeline”, U.S. patent application Ser. No. 11/807,914, filed May 30, 2007, which is hereby incorporated by reference in its entirety. These charge-transfer circuits exhibit both dynamic and static components of charge-transfer gain error. One aspect of the present invention provides for generating an adjustment-voltage component which tracks the static component of charge-transfer error.
[0072] In the discussion leading to Equations 3-6, the charge-transfer gain error was formulated in terms of the variation of charge-transfer-circuit input voltage with the amount of charge transferred. In that discussion the final value of the voltage v 43 at the input of the charge-transfer circuit was given as v 43 =v 43N +kQ OUT , with v 23N the nominal value, and k a coefficient embodying the linear dependence on Q OUT . This formulation encompasses both dynamic dependence of v 43 on Q OUT (due to incomplete settling) and static dependence. For the following discussion, it will be assumed that the dynamic effect is negligible, and the coefficient k reflects only static dependence.
[0073] It is known that the primary mechanism causing this static dependence is a voltage-feedback effect by which a voltage change at the charge-transfer circuit output causes its input voltage to change. As shown in FIG. 2 , the output voltage of a charge transfer circuit is a function of the output charge; thus the causation giving rise to the coefficient k is:
[0000] output charge→output voltage change→input voltage change
[0074] If we denote the coefficient relating output voltage change to input voltage change:
[0000] β= dv IN /dv OUT
[0000] then the coefficient k relating output charge change to input voltage change is:
[0000] k=dv IN /dQ OUT =( dv IN /dv OUT )( dv OUT /dQ OUT )=β dv OUT /dQ OUT
[0075] But d(v OUT )/d(Q OUT ) is simply the inverse of the capacitance at the charge-transfer circuit output node (which is equal to the node capacitance of the next pipeline stage). Defining that capacitance as C OUT , we then have:
[0000]
k=β/C
OUT
[0076] Referring again to FIGS. 3 and 4 , we recall that the charge-transfer error ε was given, in terms of k and the storage-node capacitance C 5 +C 6 , as ε=(C 5 +C 6 )k, leading to the expression:
[0000] ε=( C 5 +C 6 ) k =( C 5 +C 6 )β/ C OUT =β[( C 5 +C 6 )/ C OUT ] Equation 13
[0077] Thus the charge-transfer gain error ε depends on the voltage-feedback coefficient β of the charge-transfer circuit and a ratio of pipeline node capacitances. Since the pipeline node-capacitance ratios are known by design within small tolerances (discussed above), the gain error value ε can be derived from a determination of the voltage-feedback coefficient β.
[0078] FIG. 9 shows a circuit which senses the voltage-feedback coefficient β. It consists of a charge-transfer circuit 91 with input node 92 and output node 93 , a voltage source 95 connected to node 93 , and a current source 94 connected to node 92 . Charge-transfer circuit 91 is a replica of the charge-transfer circuits employed in the actual charge pipeline. Current source 94 is configured to sink from node 92 a small current which is typical of current levels near the end of the charge-transfer process described above. Voltage source 95 provides a voltage at node 93 which is in the range normally occurring at the output of the charge-transfer circuit at the end of the charge transfer process (such as voltage 42 in FIG. 4 ). Thus the charge-transfer circuit in FIG. 9 is biased in a static condition essentially like its instantaneous condition near the end of the normal (clocked) charge-transfer process.
[0079] FIG. 10 shows the voltages of the two nodes in FIG. 9 . V 93 , the voltage of node 93 , is driven cyclically by voltage source 95 between two levels 101 and 102 differing by ΔV 93 . Due to the voltage-feedback effect discussed above, the input voltage of the charge-transfer circuit (i.e., the voltage V 92 at node 92 ) responds by changing between two levels 103 and 104 , with difference ΔV 92 . By the definition above, these voltage changes are related as:
[0000] ΔV 92 =βΔV 93
[0080] Thus for a known (fixed) value of the drive voltage change ΔV 93 , ΔV 92 provides a direct measure of β. Using the known-by-design values of (C 5 +C 6 )/C OUT and the reference voltage, the appropriate adjustment voltage (V A2 in Equation 12B, for example) can be generated using known circuit techniques.
[0081] The voltage change ΔV 92 can be converted to a DC voltage using phase-sensitive detection, since the alternating drive voltage V 93 is available as a reference. The frequency of this alternating voltage is not critical, and need not be as high as the sample rate of the charge pipeline, as the parameter being sensed changes only slowly (primarily due to chip temperature changes). Because of the low current at node 92 , settling of V 92 in response to each V 93 transition is relatively slow, so the operating frequency of this circuit must be limited in order to obtain a valid settled value for ΔV 92 .
[0082] Alternatively, two circuits like that of FIG. 9 , with differing DC voltages supplied by the output-node voltage sources, thus producing two different input-node voltages, can be used to directly generate a static (DC) value of ΔV 92 . The alternating-voltage method described above is generally more accurate, however, since ΔV 92 is quite small (typically only a few mV or tens of mV).
[0083] In a practical charge pipeline, the charge-transfer circuits may not be of identical design at all stages. The β-sensing circuitry just described consumes very little power, and can practically be reproduced for each charge-transfer circuit design employed.
[0084] The circuitry described provides a correction voltage based on a charge-transfer circuit which is a replica of the charge transfer circuits in the pipeline. Such a replica-based method provides very good tracking over operating conditions, but typically has small initial mismatches. Such initial mismatches can be removed in a calibration operation, at manufacturing test or during circuit power-up for example. After the calibration, the replica-based circuit provides tracking of subsequent changes in operating conditions, including temperature and supply voltage.
[0085] Such an initial calibration step also (simultaneously) provides correction for any dynamic component of charge-transfer gain error which is present under the calibration conditions. Any change of this dynamic error with operating-condition changes (especially temperature) after calibration, however, is not corrected by the techniques of this invention.
[0086] While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. | A technique for correcting errors in Bucket Brigade Device (BBD)-based pipelined devices, such as Analog-to Digital Converters (ADCs). The gain between pipeline stages is desired to be a specific amount, such as unity: that is, all net charge present in each stage ideally is transferred to the next stage. In practical BBD-based circuits, however, the charge-transfer gain is less than ideal, resulting in errors. The approach described herein provides analog correction of such errors due to both capacitor mismatch and to sub-unity charge-transfer gain. In certain embodiments the adjustment circuit may use an adjustable current source and Field Effect Transistor to introduce the correction. In still other embodiments, the adjustment circuit may determine a voltage-feedback coefficient. | 6 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates generally to an antimicrobial coating for surgical implants, in particular, to antimicrobial coatings for meshes used in hernia and soft tissue repair.
[0003] 2. Description of the Related Art
[0004] It will be appreciated by those skilled in the art that the use of mesh for strengthening hernia and other soft tissue repair such as breast and pelvic floor reconstruction is well known. Synthetic and biological meshes have been implanted for this purpose. Synthetic meshes, generally, cause high inflammatory response and as a result become ineffective and are encapsulated owing to the immune system's foreign body response, often requiring explantation. Decellurized biological materials cause less inflammatory response but are often weaker mechanically. Synthetic materials have no antimicrobial effects to combat infections, a common problem following implant. W. L. Gore produces a product known as DUALMESH® PLUS. The mesh material, expanded PTFE, is coated with two antimicrobial preservative agents, silver carbonate and chlorhexidine diacetate, which act to inhibit bacterial colonization. The FDA classifies these inorganic compounds as toxic materials. Many patients have developed significant fever conditions following implant, consistent with toxic poisoning.
[0005] It is believed by many skilled in the art that biological materials provide some antimicrobial effect. As the biological materials degrade, growth factors and peptides are released by the degrading biological materials. The belief is that these released materials possess antimicrobial properties that help ward off potential pathogens. Experience by others has shown that any such antimicrobial properties are inadequate to substantially reduce postoperative infection rates as compared to synthetic antimicrobials.
[0006] Approximately ninety percent of post hernia repair infections are caused by Staphylococcus aureus, a gram positive pathogen. Other pathogens, both gram positive and gram negative have, to, a lesser extent, been cultured from hernia infections.
[0007] Antimicrobial substances have been impregnated in implant devices such as central venous catheters and other transdermal devices. Bayston, in U.S. patent application 20070224243 discloses such impregnated devices and methods of making them. These devices are inserted through relatively small percutaneous access points, and thus infection sources can continually enter the body from the hospital environment. To be effective, an antimicrobial agent associated with this type implant must last as long as the implant is in place and often must contain multiple agents that are effective against mutations. Because of the size of the opening, the pathogen loads are small (as compared to large surgical openings like open hernia repair wound sites), but continuous. Bayston discloses an impregnation method that slowly leaches out a mixture of antimicrobial agents that is effective up to 180 days. This impregnation method is ineffective for hernia procedures, however, partially because of the difference in the implant material and partially because of the magnitude of the bacterial challenge. Li, in U.S. Pat. No. 6,299,651 discloses the use of an antibacterial effusing textile fabric used to make clothing and other ware such as napkins The process described therein produces an antimicrobial effect after at least 25 washing cycles, to counter low challenges of microbes that might be expected to be encountered by the user of the fabric.
[0008] Hernia repair is most often preformed in an open surgical procedure. Ventral hernia repair almost always involves large abdominal openings that subject the patient to potentially large one time challenges of pathogens. Once the abdominal cavity is closed following the repair, the potentially large pathogen challenge is localized in the mesh area. Systemic antibiotic treatment is often not effective in treating the ensuing infection.
[0009] What is needed then is an antimicrobial coating for surgical mesh, and a method of manufacturing, that provides adequate localized protection against pathogens that may cause infections. What is further needed is such a non-toxic coated mesh.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a method of preparing a surgical mesh for implantation into a body, including providing a surgical mesh to be used in the body, attaching a therapeutic amount of an antimicrobial substance to the surgical mesh, and stabilizing the surgical mesh having antimicrobial substance attached thereto.
[0011] In some embodiments, the method also includes sterilizing the stabilized surgical mesh having antimicrobial substance attached thereto.
[0012] In other embodiments, the stabilizing step further includes freeze drying the surgical mesh having antimicrobial substance attached thereto, the surgical mesh having an antimicrobial effectiveness that is the same as before being stabilized.
[0013] In yet other embodiments, the stabilizing step includes maintaining the surgical mesh at a temperature below about 4 degrees Celsius.
[0014] In another aspect, the invention is directed to a method of providing a surgical mesh having a therapeutic amount of an antimicrobial substance attached thereto at a first location, the surgical mesh originating at a second location, the second location being geographically distinct from the first location, the method includes providing a surgical mesh to be used in the body, attaching a therapeutic amount of an antimicrobial substance to the surgical mesh at the second location, stabilizing the surgical mesh having antimicrobial substance attached thereto at the second location, and preparing the stabilized surgical mesh to be shipped to the first location.
[0015] In yet another aspect, the invention is directed to a surgical mesh for implantation into a body that includes a surgical mesh to be used in the body, and a therapeutic amount of an antimicrobial substance attached to the surgical mesh, wherein the surgical mesh had the antimicrobial substance attached at least 30 days prior to the use of the surgical mesh.
[0016] Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
[0017] It is to be understood that both the foregoing general description and the following detailed description of the present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and, together with the description, serve to explain the principles and operations of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 has two photographs of a microscopic view of Bard mesh prior to incubation at 40× and 100× magnifications;
[0019] FIG. 2 has two photographs of the same lysostaphin coated mesh after a 12 hour freezing cycle followed by a 12 hour lyophilization cycle;
[0020] FIG. 3 . shows photographs of a microscopic view of the same mesh after the 1 hour freeze-12 hour lyophilization cycle;
[0021] FIG. 4 is a graph illustrating turbidimetric measurements of the 1 hour freeze-12 hour lyophilized mesh in 10E8 CFU/ml Staphylococcus aureus solution before and after lyophilization using the 1 hour-12 hour cycle; and
[0022] FIG. 5 is a graph illustrating turbidimetric activity of the Bard mesh prior to sterilization and after 10 and 25 kGy exposures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Soft tissue repair mesh in current use comprises both synthetic and biological scaffolding. Infection and foreign body response are issues that affect performance of these implant materials. The current invention discloses the attachment of various antimicrobial agents to both synthetic and biological meshes in such a way as to provide effective antimicrobial action that is often needed owing to large localized bacterial challenges resulting from large abdominal openings necessary for hernia repair, particularly ventral hernias. The antimicrobial agent must be bound to the mesh in an amount and in such a way as to allow the mesh to be inserted into the surgical field such that antibacterial action can take place both from leached (free) and bound antimicrobial molecules. The “microscopic” area of the mesh must be adequate to allow surface adsorption of ample antimicrobial agent molecules to counter the magnitude of the bacterial challenge, either through leaching, bound state action, and/or both.
[0024] There are many known antimicrobial agents in the art that might be useful as coatings for implant mesh. Among them are lysostaphin, triclosan, ethanol, LL-37 peptide, various human defensins, and combinations of these and other antibiotics. The ideal requirements are that the agents should be non-toxic and be readily attached to the mesh in such quantities as to be effective against large bacterial challenges, 10E8 CFUs/ml for example.
Protocols for Preparation of the Preferred Embodiments
[0025] Protocol for Coating Meshes with Lysostaphin (Adsorption Protocol)
[0026] 1). The mesh material was cut into 3×3 cm pieces in a laminar flow hood under sterile conditions prior to physical adsorption.
[0027] 2). The samples pieces were then placed in a sterile 50 ml conical tube and incubated in 30 ml PBS buffer (10 mM phosphate; 140 mM NaCl, 3 mM KCl; pH-7.4) at room temperature (RT) for 30 minutes. As per manufacturer's instructions (Calbiochem—Cat #524650) dissolving one PBS tablet in 1 liter of deionized H2O yields 140 mM NaCl, 10 mM phosphate buffer, and 3 mM KCl, pH 7.4.
[0028] 3). The solution was discarded and the samples were then gently flushed several times with PBS buffer.
[0029] 4). The samples were incubated in 30 ml of PBS buffer at RT for 30 minutes and step 3 was repeated.
[0030] 5). The lysostaphin (Sigma Aldrich—L7386; lyophilized powder—5 mg, Protein˜50-70%; remaining NaCl) was re-suspended in 1 ml of sterile PBS (autoclaved at 121° C.).
[0031] 6). Initial lysostaphin concentrations 0.025, 0.05, 0.1, 0.25, and 0.5 mg/ml PBS buffer were prepared from a 1 mg/ml stock solution of Lysostaphin.
[0032] 7). One ml of protein samples was then added to sterile (autoclaved at 121° C.) 25 ml glass vials (VWR—Cat #66012-044) in a laminar flow hood under sterile conditions.
[0033] 8). The mesh samples were gently placed into each of the vials containing the protein solutions and incubated overnight at room temperature (preferably in an incubator/shaker).
[0034] 9). The sample solution was removed after overnight incubation and then gently flushed several times with PBS buffer using a 1 ml pipette.
[0035] 10). The samples were then stored prior to use at 4° C. in 1 ml of PBS buffer.
[0036] Protocol for Fluorescence Measurements of Lysostaphin Residual on the Mesh
[0037] Alexa Fluor 594-labeled lysostaphin is prepared according to the manufacturer's instruction. The initial fluorescence intensity of the enzyme sample solution is measured using a microplate reader (Ex 594 nm; Em 625 nm).
[0038] The mesh is then incubated in the labeled solution at room temperature for one hour with varying lysostaphin concentrations making sure the mesh is entirely covered with solution. After incubation the mesh is washed 2 times with copious amounts of PBS buffer. The samples were then added to sterile glass vials containing the enzyme solution and incubated overnight at room temperature with gentle shaking (100 rpm). The enzyme solution over the mesh was then collected and stored for fluorescence measurements, and the mesh was gently washed 2 times with 1 ml of PBS buffer. The wash solution was also collected and used in determination of enzyme residual. To remove any loosely adsorbed enzyme, 1 ml of 0.1 (v/v %) Tween 20 solution (non-ionic surfactant) is then added to the glass vials followed by incubation for 3 hours. This surfactant solution is also collected and used in the determination of the amount of desorbed enzyme, and the mesh samples are again washed with copious amount of PBS buffer. The concentration of unbound enzyme in each of the supernatants and wash solutions is determined from fluorescence measurements. The initial enzyme solution with known concentrations is used as the standards. The concentration of the unbound enzyme at each step is then calculated and subtracted from initial concentration of enzyme present in the initial solution. The difference in the concentrations corresponded to the residual enzyme concentration on the mesh. The fluorescence measurements showed zero residual on the mesh within the sensitivity of the measurements, 150 micrograms per gram of mesh. The weight of lysostaphin residual on the mesh versus initial concentration of the incubation solution is the recorded.
[0039] Table I depicts the results of fluorescence measurements of lysostaphin residual on various meshes, both biologic and synthetic, using the above protocols for incubation and measurements of lysostaphin residual on the meshes.
[0000]
Concentration,
Adsorption Amount,
Mesh (Manufacturer)
μgm/ml
μgm (μgm/cm{circumflex over ( )}2)
Biologic Meshes (3 × 3 cm patches)
FlexHD ® (MTF)
25
56
(6.2)
50
90
(10)
100
224
(25)
300
569
(63)
500
955
(106)
Strattice ® (Life Cell)
25
53
(5.9)
50
72
(8.0)
100
146
(16)
300
435
(48)
500
677
(75)
Permacol ® (Covidien)
25
28.0
(3.1)
50
65.3
(7.3)
100
150
(16.6)
300
500
533
(59)
Alloderm ®(Life Cell)
25
50
74.4
(8.3)
100
139
(15.4)
300
500
Synthetic Meshes (3 × 3 cm patches)
Bard ™ (CR Bard)
25
42
(4.6)
50
50
(5.6)
100
139
(15.4)
300
262
(29)
500
246
(27)
Parietex ® (Covidien)
25
35
(3.9)
50
57
(6.3)
100
116
(13)
300
357
(40)
500
452
(50)
[0040] In Vivo Studies Protocol
[0041] All animal experiments were approved by the Institutional Animal Care and Use Committee (CMC) and performed in accordance with NIH guidelines. Surgical anesthesia was induced and maintained with inhaled isofluorane. The abdominal wall was shaved, prepared with Betadine® and isopropyl alcohol 70% (v/v), and draped in sterile fashion. A 1 cm midline vertical incision was made through dermis, and a pocket was then created by elevating the skin and subcutaneous tissue from the anterior abdominal fascia bilaterally. Sterile mesh 3 cm×3 cm was placed on the fascia and secured with 4-0 Prolene suture. One-by-one cm meshes were used for ex-vivo testing of anti-microbial activity. Three-by-three cm meshes were utilized for long-term studies including animal survival and gross and microscopic evaluation. Bacterial inoculation was performed by applying a 1 cc suspension of Staph aureus directly on the mesh. The incision was closed using vicryl suture and reinforced with skin staples. Topical Bitter Orange (ARC Laboratories, Atlanta, Ga.) was applied over the closure to dissuade animal-induced wound disruption. All animals received bupranorphine (0.03 mg/kg) immediately after surgery and every 12 hours thereafter for the next 48 hours.
[0042] Mesh harvest was performed surgically in a sterile fashion. General anesthesia was induced with isofluorane and the animals were euthanized by intracardiac pentobarbital injection after collecting blood samples for analysis. The skin around the original incision was prepared in the same fashion as above and opened sharply and widely to allow full exposure of the implant. The entire abdominal wall including the mesh was excised en bloc for analysis.
[0043] Table II depicts bacterial count from explanted meshes after 7 days in vivo. Four animals in each of two study arms were inculcated with 5×10E5 CFUs of Staphylococcus aureus at the time of implant. The bacteria were placed on the center of the abdominal patch prior to wound closure. Controls (No LYS) were implanted with uncoated biological and synthetic meshes. The animals in the second arm (LYS) were implanted with biological and synthetic meshes each with incubation concentrations adjusted to yield a lysostaphin concentration of 15.4 μgms/cm̂2 of mesh geometrical surface area by extrapolating the data in Table I. (For example Alloderm was incubated in 100 μgms/ml solution). A third arm of four animals with each mesh comprised implants with no lysostaphin and no bacteria (No LYS, No bacteria).
[0000]
TABLE II
Average Bacterial Count after 7 Days
Bacterial
Bacteria Count
Count
Bacterial Count
(No LYS,
Mesh (Manufacturer)
(No LYS)
(LYS)
No bacteria)
Biologic Meshes (3 × 3 cm patches)
FlexHD ® (MTF)
8.8 × 10E6
0
0
Strattice ® (Life Cell)
6.9 × 10E6
0
0
Permacol ® (Covidien)
1.9 × 10E8
0
0
Alloderm ®(Life Cell)
5.2 × 10E6
0
0
Synthetic Meshes (3 × 3 cm patches)
Parietex ® (Covidien)
1.5 × 10E8
0
0
Bard ™ (CR Bard)
2.8 × 10E6
0
0
[0044] Histology Measurements Protocol
[0045] Tissue histology was evaluated after implantation of lysostaphin-bound mesh in the presence of a large S. aureus innoculum. Mesh explantation was performed at 60 days. Specimens were prepared for light microscopy analysis. Hematoxylin and Eosin staining and Milligan's Trichrome staining were performed. The entire mesh-tissue interface on the slide was examined at low-power magnification (20×). A quantitative assessment by two blinded evaluators was made by counting the number of neutrophils and macrophages and amount of fibroblast in a fixed number of high-powered fields (40×). Histological assessment results were averaged prior to analysis (n=10).
[0046] Table III depicts the average histology results for 10 samples prepared as described above.
[0000]
Mesh
Lymphocytes
Neutrophils
Fibroblast
Strattice ® (Life Cell)
2.0
1.1
4.25
No Lys, No SA
Strattice ® (Life Cell)
2.0
1.4
2.1
Lys, 10E6 SA
Strattice ® (Life Cell)
2.1
1.1
3.2
Lys, 10E8 SA
[0047] The number of lymphocytes, neutrophils and amount of fibroblast for LYS coated mesh for both 10E6 and 10E8 inoculums were not significantly different from the controls (no LYS and no innoculum), p>0.05.
[0048] Protocol for Shear Strength Measurements
[0049] Sterile 3×3 cm mesh patches were implanted in the overlay method in the abdomen of 250-450 gram Sprague Dawley rats and harvested after 60 days. The study consisted of four arms: non lysostaphin coated mesh with no bacteria inoculum; meshes coated with 15.4 μgms/cm̂2 of lysostaphin with no inoculum: and two arms of lysostaphin coated meshes (15.4 μgms/cm̂2), one with 10E6 and one with 10E8 CFUs of Staphylococcus aureus respectively, n=10 for each leg. At harvest the patches were well attached to the abdominal tissue owing to tissue ingrowth. The patches were explanted along with the ingrown tissue attached underneath the patches. Individual samples were attached to a Mecmesin tensile testing device, model Multi-Test 1-i (1 kN). The underling tissue was clamped to one leg of the tester and the mesh to the other leg. The tester was set at 5 mm/min speed for removing the mesh from the tissue. The peak load (dominantly shear force) and the total energy required to separate the two components were recorded. Comparisons of the measurements were assumed to be a measure of the tissue ingrowth efficacy of the meshes with and without lysostaphin coatings and with and without bacteria inoculum.
[0050] Table IV depicts the peak load and pull-off energy (average n=10) for a biological meshes 60 days after implant.
[0000]
Peak-Force,
Energy,
Mesh
Coating
Inoculum
N
mJ
Strattice ® (Life Cell)
None
None
7.7
49.0
Strattice ® (Life Cell)
Lysostaphin
None
15.7
118
Strattice ® (Life Cell)
Lysostaphin
10E6
11.7
90.3
Strattice ® (Life Cell)
Lysostaphin
10E8
17.3
130
[0051] The peak load and the removal energy, and presumably the degree of in-growth, were significantly higher for the lysostaphin coated mesh samples (p<<0.05). The peak load and energy of the lysostaphin no bacteria, coated mesh samples and each set of bacteria inoculated samples were not significantly different (p>0.05). It should be noted that the above mesh is not cross-linked.
[0052] Leaching Measurement Protocol
[0053] Leaching of bound lysostaphin is an important parameter to be examined while determining the effectiveness of such antibacterial meshes. In this regard in vitro leaching was monitored over 72 hours. Leaching measurements were performed with lysostaphin coated meshes submersed in 2% (20 mg/ml) BSA-150 mM PBS solution. Meshes, placed in 25 ml amber jars, were incubated in fluorescently labeled lysostaphin solution for one hour and washed according to the adsorption protocol. Two-tenths of a ml of initial lysostaphin solution utilized for these various meshes was retained so as to obtain a standard curve to determine the leached fraction. Also, a control mesh, without lysostaphin, was incubated in 150 mM PBS solution under the same protocol as the adsorption protocol. The jars were then wrapped in aluminum foils, after adsorption, to prevent photo bleaching of fluorescently labeled enzyme. This was followed by incubation of the meshes, under mild shaking, in 3 ml of 2% BSA at 37° C. for 24-72 hrs. 0.2 ml aliquots, containing the leached enzyme, were collected at specified time points. Simultaneously, the same volume of 2% BSA-150 mM PBS was added to the meshes at each of these time points so as to maintain the existing 3 ml volume present before withdrawal of 0.1 ml from these aliquots. A standard curve was obtained for 0.1 ml of labeled enzyme; after performing a two-fold serial dilution of 1 mg/ml labeled lysostaphin using a microplate reader. (Ex 594 nm and Ex 625 nm resp). The amount of leached enzyme was obtained from the standard curve after subtracting the fluorescence value of the control from that of the sample fluorescence value at each time point. All fluorescence measurements of the standards and unknown were done simultaneously. The fraction of leached enzyme was calculated using the known amount of enzyme adsorbed onto the mesh after adsorption and plotted as a function of time.
[0054] Table V depicts the leach rate of various meshes as measured according to the above protocol.
[0000]
Mesh, (Manufacturer) (Initial
Time
Amount Leached
Percent
Amount Adsorbed, μgm)
Hours
(μgm)
Leached
Biologic Meshes
FlexHD ® (MTF) (223.7)
0.5
1.4
0.6
6
8.8
3.9
12
15.9
7.1
24
20.8
Strattice ® (Life Cell) (146.3)
0.5
16
10.9
6
16.3
11.1
12
28.9
19.8
24
23.7
Permacol ® (Covidien) (133.7)
0.5
14.3
10.7
5
18.3
13.7
24
16.9
12.6
72
24.3
18.2
Synthetic Meshes
Parietex ® (Covidien) (133.7)
0.5
11.2
6.5
6
17.2
10
12
31.0
18
24
27.0
15.7
Bard ™ (CR Bard) (104.7)
0.5
2.1
2.0
6
9.1
8.7
12
19.8
18.9
24
23.3
22.3
Ultra Pro ® Ethicon (128.6)
0.5
0.96
0.74
6
14.2
11.0
12
19.8
15.4
24
18.7
14.5
[0055] Turbidimetric Activity Assay
[0056] As per the instructions of the vendor, ATCC, the Staphylococcus aureus cell suspension was grown by inoculating 15 ml of 3% (w/v) Tryptic soy with 100 μL of S. aureus culture. Mid-log phase growth was achieved by incubating the cells at 370° C. for 18-24 hours. The cells were then centrifuged at 8,000 RPM for 10 min and re-suspended in 150 mM PBS to obtain a final optical density of ˜0.6 at 600 nm. 1 mL of cells containing ˜10E8 CFU (colony forming units) was added to vials containing 1×1 mesh samples. The samples were incubated with the cell suspension at 37° C. under continuous shaking, and the rate of bacterial lysis was monitored for 24 hours by taking 0.2 mL aliquots from the reaction mixture and measuring the optical density at 600 nm in a 96 well plate at different time intervals.
[0057] Lyophilization (Freeze Drying) Protocol
[0058] Employing a Labconco Freezone 4.5 catalog #7750000 freeze dryer, two different lysostaphin coated mesh samples were subjected to −80° C. for two different times (one sample for one hour and the other for 12 hours) before being lyophilized for 12 hours. Following this process the samples were tested for activity according to the Turbidimetric Activity Assay procedure. FIG. 1 is microscopic photographs of Bard mesh prior to incubation at 40× and 100× magnification. FIG. 2 has two photographs of the same lysostaphin coated mesh after a 12-hour freezing cycle followed by a 12-hour lyophilization cycle. The crystalline-like structures are seen surrounding the mesh filaments (polypropylene) which is believed to be residual salts from the PBS solution used in the coating process. Samples freeze dried using the 12-hour freeze and then the 12-hour lyophilization cycle showed little or no activity against Staphylococcus aureus. FIG. 3 shows pictures of the same microscopic views of the mesh after the 1-hour freeze and then the 12-hour lyophilization cycle. There is no evidence of crystallization. FIG. 4 depicts turbidimetric measurements of the 1 hour freeze-12 hour lyophilized mesh in 10E8 CFU/ml Staphylococcus aureus solution along with controls (no mesh samples) before and after lyophilization using the 1-hour-12-hour cycle.
[0059] Lysostaphin is stable for more than six (6) months when kept at 4° C. and longer at lower temperatures. Thus, an alternate to freeze drying a lysostaphin coated mesh is storing it at or below 4° C.
[0060] Sterilization Testing Protocol
[0061] Following lyophilization using the 1 hour-12 hour cycle, mesh samples were placed into Dispos-a-vent, medical grade pouches provided by Oliver Tolas Healthcare Packaging (Hamilton, Ohio). Prior to packaging these meshes, the pouches were purged with 99% pure compressed nitrogen gas for 5 minutes and then the meshes were placed within the pouches using forceps, which were cleansed with ethanol, and the pouches were heat sealed. These pouches were sterilized using e-beam sterilization at exposure levels of 10 and 25 kGy. FIG. 5 shows turbidimetric activity of the Bard mesh prior to sterilization and after the 10 and 25 kGy exposures.
[0062] Accelerated Shelf Life Testing Protocol
[0063] Samples of lysostaphin coated Bard mesh were sealed in pouches as described above and placed into a temperature controlled oven at 50° C. for 10 weeks. The (average n=4) activity of the coated mesh samples were measured by turbidimetric activity assay as described above at various time points before and after the 10 week oven exposure (See FIG. 6 ). Those skilled in the art will recognize that for first order systems, 50° C. for 10 weeks exposure is equivalent to approximately 80 weeks at 20° C., depending upon the activation energy of the reaction.
[0064] Samples were also placed into a temperature controlled oven at 60° C. for 3 weeks. However, as illustrated in FIG. 6 , the activity of the lysostaphin was severely affected by the temperature. It appears that the temperature was too high, disrupting the lysostaphin rather than aging the packaging in any meaningful way.
[0065] The inventors have discovered that 15.4 μgm of lysostaphin adsorbed on a square centimeter of geometrical area of implanted mesh is adequate for eradicating an innoculum of 10E8 CFUs of staphylococcus aureus in vivo using a rat model, for both synthetic and biological mesh. This surface concentration is adequate to supply wound infection protection via leaching and protection against implant infection.
[0066] The following examples are indicative of the preferred embodiments of the method of utilizing and applying this invention:
EXAMPLE 1
[0067] Mesh samples, 3×3 cm, were coated with 15.4 μgm/cm̂2 of lysostaphin, a value arrived at by interpolating the adsorption data from Table I. The results are shown in Table VI below.
[0000]
LYS concentration for adsorption of
Mesh (Manufacturer)
15 μgm/cm{circumflex over ( )}2, μgm/ml
FlexHD ® (MTF)
68
Strattice ® (Life Cell)
98
Permacol ® (Covidien)
86
Alloderm ® (Life Cell)
100
Parietex ® (Covidien)
118
Bard ™ (CR Bard)
100
[0068] Incubating the above meshes as per the coating protocol (n=10 in each study arm), using the concentrations in Table VI, and verifying the adsorbed amount by the florescence protocol above, implanting them in a rat models for 60 days with Staph A inoculums of either 10E6 or 10E8 CFUs resulted in no wound infections, no mesh infections, no residual bacteria count, and no visual or clinical effects on the rats. Of the control rats with no lysostaphin and with 10E8 inoculum 100% died or required euthanization because of wound failures prior to the 60 day study length. Thus, the lysostaphin mesh coating and the leached lysostaphin as per Table V protected the animals against mesh and wound infections.
EXAMPLE 2
[0069] Three sets of samples of Strattice mesh (3×3 cm) were coated with 15.4 μgm/cm̂2 of lysostaphin as per the above protocol (n=10 in each study arm), and implanted in rat models. The control arm consisted of mesh without lysostaphin coating and the two coated arms were inoculated with 10E6 and 10E8 CFUs of Staph A. All samples were harvested after 60 days. Both lysostaphin arms showed significantly higher pull-off strength from the underlying tissue compared to those in the control arm, thus indicating that the coated meshes encouraged better tissue ingrowth when tested as per the above protocol. In addition, histology cell counts as per the above protocol showed no significant differences between the three arms.
EXAMPLE 3
[0070] Mesh samples were freeze dried with the 1 hour freeze and 12 hour drying cycle as described above following coating with lysostaphin. The Turbidimetric Activity Assay before and after the lyophilization were not significantly different indicating that this freeze/dry cycle preserves lysostaphin coated mesh activity against Staph A.
EXAMPLE 4
[0071] Lysostaphin coated mesh samples were lyophilized as per the protocol above, packaged as described above and radiation sterilized at 10 and 25 kGy. Turbidimetric Activity Assay was made before and after sterilization with no significant difference between the pre and post sterilization samples indicating that radiation sterilization of this magnitude has no effect on the coated lysostaphin mesh activity against Staph A.
EXAMPLE 5
[0072] Lysostaphin coated mesh samples were freeze dried, packaged, and sterilized as per the above protocols and placed into a 50° C. oven for 10 weeks. Turbidimetric Activity Assay of pre and post oven samples was performed and no significant difference in activity was found. This indicates that the shelf life of sealed, sterilized lysostaphin coated meshes have a shelf life greater than 1 year.
EXAMPLE 6
[0073] Immediately following the buffer solution coating process, the surgical mesh was packaged as above, and was kept at 4° C. or lower and sterilized by electron beam. The packaged mesh was then stored and a Turbidimetric Activity Assay of pre and post storage of these samples was performed and no significant difference in activity was found in the pre and the post stored samples. It should be noted that while electron beam sterilization was used in this example, other sterilization radiation (e.g., gamma), could be used as well.
[0074] Typically, the effectiveness of the antimicrobial properties only last for a short period of time (usually measured in hours), meaning that the surgical mesh would have to be prepared either on-site (even in the operating room) or very close by for the coated surgical mesh to be effective. But since it has been discovered that the effectiveness can be preserved with both of the stabilization methods noted above, either freeze-dried or maintained at least at about 4° C., the coated surgical mesh can be prepared off-site and prior to it being needed and then shipped to a destination for use in surgery after the stabilization of the mesh.
[0075] And it will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A surgical mesh has a therapeutic amount of an antimicrobial substance attached to the mesh. The surgical mesh is then stabilized by either freeze drying or keeping cold after attaching the antimicrobial substance. The surgical mesh is then sterilized with an electron beam. The stabilization of the surgical mesh allows the mesh to be used up to a year after the antimicrobial substance is attached and still be effective against bacteria. | 3 |
REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 USC 119(e) from U.S. Patent application No. 60/288,415 filed May 4, 2001, 60/326,987 filed Oct. 5, 2001, 60/331,066 filed Nov. 7, 2001, 60/333,494 filed Nov. 28, 2001 and 60/374,801 filed Apr. 24, 2002.
FIELD OF THE INVENTION
The present invention relates to improved methods for manufacturing oil seed protein isolate, particularly a canola protein isolate.
BACKGROUND TO THE INVENTION
In U.S. Pat. Nos. 5,844,086 and 6,005,076 (“Murray II”), assigned to the assignee hereof and the disclosures of which are incorporated herein by reference, there is described a process for the isolation of protein isolates from oil seed meal having a significant fat content, including canola oil seed meal having such content. The steps involved in this process include solubilizing proteinaceous material from oil seed meal, which also solubilizes fat in the meal, and removing fat from the resulting aqueous protein solution. The aqueous protein solution may be separated from the residual oil seed meal before or after the fat removal step. The defatted protein solution then is concentrated to increase the protein concentration while maintaining the ionic strength substantially constant, after which the concentrated protein solution may be subjected to a Per fat removal step. The concentrated protein solution then is diluted to cause the formation of a cloud-like mass of highly associated protein molecules as discrete protein droplets in micellar form. The protein micelles are allowed to settle to form an aggregated, coalesced, dense, amorphous, sticky gluten-like protein isolate mass, termed “protein micellar mass” or PMM, which is separated from the residual aqueous phase and dried.
The protein isolate has a protein content (as determined by Kjeldahl N×6.25) of at least about 90 wt %, is substantially undenatured (as determined by differential scanning calorimetry) and has a low residual fat content. The term “protein content” as used herein refers to the quantity of protein in the protein isolate expressed on a dry weight basis. The yield of protein isolate obtained using this procedure, in terms of the proportion of protein extracted from the oil seed meal which is recovered as dried protein isolate was generally less than 40 wt %, typically around 20 wt %.
The procedure described in the aforementioned Murray II patent was developed as a modification to and improvement on the procedure for forming a protein isolate from a variety of protein source materials, including oil seeds, as described in U.S. Pat. No. 4,208,323 (Murray IB). The oil seed meals available in 1980, when U.S. Pat. No. 4,208,323 issued, did not have the fat contamination levels of the canola oil seed meals available at the time of the Murray II patents, and, as a consequence, the procedure of U.S. Pat. No. 4,208,323 cannot produce from such oil seed meals processed according to the Murray II process, proteinaceous materials which have more than 90 wt % protein content. There is no description of any specific experiments in U.S. Pat. No. 4,208,303 carried out using rapeseed (canola) meal as the starting material.
U.S. Pat. No. 4,208,323 itself was designed to be an improvement on the process described in U.S. Pat. Nos. 4,169,090 and 4,285,862 (Murray IA) by the introduction of a concentration step prior to dilution to form the PMM. The Murray IA patents describe one experiment involving rapeseed but provides no indication of the purity of the product. The concentration step described in the Murray IB patent served to improve the yield of protein isolate from around 20% for the Murray IA process.
SUMMARY OF INVENTION
It has now been found that it is possible to improve these prior art protein isolate processes as they apply to oil seeds, particularly canola, to obtain improved yields of dried protein isolate, in terms of the proportion of protein extracted from the oil seeds, of at least about 40 wt % and often much higher, at least about 80 wt %, and protein isolates of higher purity, at least about 100 wt % at a Kjeldahl nitrogen conversion rate of N×6.25.
It has Dryer been found that a significant proportion of the canola protein extracted from the meal in the process of Murray IA and IB and Murray II, as applied to canola meal, is lost as a result of discarding the supernatant from the PMM-formation step. A further improvement on the prior procedure is provided herein, which improves the overall yield of protein, wherein protein present in the supernatant is recovered generally by a process of concentration to remove impurities and drying the concentrate. The product obtained from the supernatant generally has a protein content (N×6.25) of greater than 100% and is a novel canola protein isolate product. Such novel product provides a flier aspect of the invention.
As a further improvement on the prior procedure, the concentrated supernatant may be mixed with the PMM and the mixture dried. Alternatively, a portion of the concentrated supernatant may be mixed with at least a portion of the PMM and the resulting mixture dried. The latter products are novel canola protein isolate products and constitute a further aspect of the invention.
In accordance with one aspect of the present invention, there is provided a process of preparing a protein isolate, which comprises (a) extracting an oil seed meal at a temperature of at least about 5° and preferably up to about 35° C. to cause solubilization of protein in said oil seed meal and to form an aqueous protein solution having a protein content of about 5 to about 25 g/L and a pH of about 5 to about 6.8, (b) separating the aqueous protein solution from residual oil seed meal, (c) increasing the protein concentration of said aqueous protein solution to at least about 200 g/L while maintaining the ionic strength substantially constant by using a selective membrane technique to provide a concentrated protein solution, (d) diluting said concentrated protein solution into chilled water having a temperature of below about 15° C. to cause the formation of protein micelles; (e) settling the protein micelles to form an amorphous, sticky, gelatinous gluten-like protein micellar mass, and (f) recovering the protein micellar mass from supernatant having a protein content of at least about 100 wt % as determined by Kjeldahl nitrogen×6.25 on a dry weight basis. The recovered protein micellar mass may be dried. The protein isolate is substantially undenatured (as determined by differential scanning calorimetry).
The protein isolate product in the form of protein micellar mass is described herein as “gluten-like”. This description is intended to indicate the appearance and feel of the isolate are similar to those of vital wheat gluten and is not intended to indicate chemical identity to gluten.
In one embodiment of this process, supernatant from the settling step is concentrated and the resulting concentrated supernatant is dried to provide a protein isolate having a protein content of at least about 90 wt % (N×6.25) on a dry weight basis. Such protein isolate is a novel product and is provided in accordance with further aspect of the invention.
In another embodiment of this process, supernatant from the settling step is concentrated, the resulting concentrated supernatant is mixed with the protein micellar mass prior to drying the same, and the resulting mixture is dried to provide a protein isolate having a protein content of at least about 90 wt % (N×6.25) on a dry weight basis. Such protein isolate is a novel product and is provided in accordance with another aspect of the invention.
In a further embodiment of the invention, supernatant from the resulting step is concentrated and a portion only of the resulting concentrated supernatant is mixed with at least a portion of the protein micellar mass prior to drying the same to provide other novel protein isolates according to the invention having a protein content of at least about 90 wt % (N×6.25) on a dry weight basis.
A key step in the process of the present invention and the ability to obtain higher yields of protein isolate at purities of at least 100 wt % than previously attained is concentration of the protein solution to a protein content of at least about 200 g/L, a much higher value than in the prior procedures described above. Another key step is the step of warming the concentrated protein solution, as necessary, prior to dilution into chilled water at a dilution rate of less than 1:15, when protein micellar mass only is recovered. This specific combination of parameters is not described in the prior art nor are the beneficial results of high protein yield and high purity protein isolate described therein. An additional step in improving protein yield, particularly in the case of canola meal, is the recovery of additional quantities of protein from the supernatant from the PMM formation and settling step.
In accordance with another aspect of the invention, there is provided a process for preparing a canola protein isolate of reduced pigmentation, which comprises (a) extracting canola oil seed meal at a temperature of at least 5° C. to cause solubilization of protein in said canola oil seed meal and to form an aqueous protein solution having a protein content of about 5 to about 25 g/L and a pH of about 5 to about 6.8; (b) separating the aqueous protein solution from residual canola oil seed meal; (c) subjecting the aqueous protein solution to a pigment removal step; (d) increasing the protein concentration of said aqueous protein solution to at least about 200 g/L while maintaining the ionic strength substantially constant by using a selective membrane technique to provide a concentrated protein solution; (e) diluting said concentrated protein solution into chilled water having a temperature below about 15° C. to cause the formation of protein micelles; (f) settling the protein micelles to form an amorphous, sticky, gelatinous, gluten-like micellar mass; and (g) recovering the protein micellar mass from supernatant having a protein content of at least about 90 wt % as determined by Kjeldahl nitrogen×6.25 on a dry weight basis.
The protein isolate produced according to the process herein may be used in conventional applications of protein isolates, such as, protein fortification of processed foods, emulsification of oils, body formers in baked goods and foaming agents in products which entrap gases. In addition, the protein isolate may be formed into protein fibers, useful in meat analogs, may be used as an egg white substitute or extender in food products where egg white is used as a binder. The canola protein isolate may be used as nutritional supplements. Other uses of the canola protein isolate are in pets foods, animal feed and in industrial and cosmetic applications and in personal care products.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic flow sheet of a procedure for producing an oil seed protein isolate as well as other products in accordance with one embodiment of the invention.
GENERAL DESCRIPTION OF INVENTION
The initial step of the process of this invention involves solubilizing proteinaceous material from oil seed meal, particularly canola meal, although the process may be applied to other oil seed meals, such as soybean, traditional rapeseed, traditional flax, linola, sunflower and mustard oil seed meals. The invention is more particularly described herein with respect to canola seed meal.
The proteinaceous material recovered from canola seed meal may be the protein naturally occurring in canola seed or other oil seed or the proteinaceous material may be a protein modified by genetic manipulation but possessing characteristic hydrophobic and polar properties of the natural protein. The canola meal may be any canola meal resulting from the removal of canola oil from canola oil seed with varying levels of non-denatured protein, resulting, for example, from hot hexane extraction or cold oil extrusion methods. The removal of canola oil from canola oil seed usually is effected as a separate operation from the protein isolate recovery procedure of the present invention.
Protein solubilization is effected most efficiently by using a food grade salt solution since the presence of the salt enhances the removal of soluble protein from the oil seed meal. The food grade salt usually is sodium chloride, although other salts, such as, potassium chloride, may be used. The food grade salt solution has an ionic strength of at least about 0.10, preferably at least about 0.15, to enable solubilization of significant quantities of protein to be effected. As the ionic strength of the salt solution increases, the degree of solubilization of protein in the oil seed meal initially increases until a maximum value is achieved. Any subsequent increase in ionic strength does not increase the total protein solubilized. The ionic strength of the food grade salt solution which causes maximum protein solubilization varies depending on the salt concerned and the oil seed meal chosen.
In view of the greater degree of dilution required for protein precipitation with increasing ionic strengths, it is usually preferred to utilize an ionic strength value less than about 0.8, and more preferably a value of about 0.15 to about 0.6.
The salt solubilization of the protein is effected at a temperature of at least about 5° C., preferably up to about 35° C., preferably accompanied by agitation to decrease the solubilization time, which is usually about 10 to about 60 minutes. It is preferred to effect the solubilization to extract substantially the maximum amount of protein from the oil seed meal, so as to provide an overall high product yield.
The lower temperature limit of about 5° C. is chosen since solubilization is impractically slow below this temperature while the preferred upper temperature limit of about 35° C. is chosen since the process becomes uneconomic at higher temperature levels in a batch mode.
The aqueous food grade salt solution and the oil seed meal have a natural pH of about 5 to about 6.8 to enable the protein isolate to be formed by the micellar route, as described in more detail below. The optimum pH value for maximum yield of protein isolate varies depending on the oil seed meal chosen.
At and close to the limits of the pH range, protein isolate formation occurs only partly through the micelle route and in lower yields than attainable elsewhere in the pH range. For these reasons, pH values of about 5.3 to about 6.2 are preferred.
The pH of the food grade salt solution may be adjusted to any desired value within the range of about 3 to about 6.8 for use in the extraction step by the use of any convenient food grade acid, usually hydrochloric acid, or food grade alkali, usually sodium hydroxide, as required.
The concentration of oil seed meal in the food grade salt solution during the solubilization step may vary widely. Typical concentration values are about 5 to about 15% w/v.
The protein extraction step with the aqueous salt solution has the additional effect of solubilizing fats which may be present in the canola meal, which then results in the fats being present in the aqueous phase.
The protein solution resulting from the extraction step generally has a protein concentration of about 5 to about 30 g/L, preferably about 10 to about 25 g/L.
The aqueous phase resulting from the extraction step then may be separated from the residual canola meal, in any convenient manner, such as by employing vacuum filtration, followed by centrifugation and/or filtration to remove residual meal. The separated residual meal may be dried for disposal.
The colour of the final canola protein isolate can be improved in terms of light colour and less intense yellow by the mixing of powdered activated carbon or other pigment adsorbing agent with the separated aqueous protein solution and subsequently removing the adsorbent, conveniently by filtration, to provide a protein solution. Diafiltration of the separated aqueous protein solution also may be used for pigment removal.
Such pigment removal step may be carried out under any convenient conditions, generally at the ambient temperature of the separated aqueous protein solution, employing any suitable pigment adsorbing agent. For powdered activated carbon, an amount of about 0.025% to about 5% w/v, preferably about 0.05% to about 2% w/v, is employed.
Where the canola seed meal contains significant quantities of fat, as described in the Murray II patents, then the defatting steps described therein may be effected on the separated aqueous protein solution and on the concentrated aqueous protein solution. When the colour improvement step is carried out, such step may be effected after the first defatting step.
As an alternative to extracting the oil seed meal with an aqueous food grade salt solution, such extraction may be made using water alone, although the utilization of water alone tends to extract less protein from the oil seed meal than the aqueous food grade salt solution. Where such alternative is employed, then the food grade salt, in the concentrations discussed above, may be added to the protein solution after separation from the residual oil seed meal in order to maintain the protein in solution during the concentration step described below. When a colour removal step and/or a first fat removal step is carried out, the food grade salt generally is added after completion of such operations.
Another alternative procedure is to extract the oil seed meal with the food grade salt solution at a relatively high pH value about 6.8, generally up to about 9.8. The pH of the food grade salt solution, may be adjusted in pH to the alkaline value by the use of any convenient food-grade alkali, such as aqueous sodium hydroxide solution Where such alternative is employed, the aqueous phase resulting from the oil seed meal extraction step then is separated from the residual canola meal, in any convenient manner, such as by employing vacuum filtration, followed by centrifugation and/or filtration to remove residual meal. The separated residual meal may be dried for disposal.
The aqueous protein solution resulting from the high pH extraction step then is pH adjusted to the range of about 5 to about 6.8, preferably about 5.3 to about 6.2, as discussed above, prior to further processing as discussed below. Such pH adjustment may be effected using any convenient food grade acid, such as hydrochloric acid.
The aqueous protein solution then is concentrated to increase the protein concentration thereof while maintaining the ionic strength thereof substantially constant. Such concentration is effected to provide a concentrated protein solution having a protein concentration of at least about 200 g/L, preferably at least about 250 g/L.
The concentration step may be effected by any convenient selective membrane technique, such as ultrafiltration or diafiltration, using membranes, such as hollow-fibre membranes or spiral-wound membranes, with a suitable molecular weight cut-off, such as about 3000 to about 50,000 daltons, having regard to differing membrane materials and configurations.
The concentration step may be effected at any convenient temperature, generally about 20° C. to about 60° C., and for the period of time to effect the desired degree of concentration. The temperature and other conditions used to some degree depend upon the membrane equipment used to effect the concentration and the desired protein concentration of the solution.
The concentrating of the protein solution to a concentration above about 200 g/L in this step, significantly beyond levels previously contemplated and attained when employing the Murray I and Murray II processes, not only increases the process yield to levels above about 40 wt % in terms of the proportion of extracted protein which is recovered as dried protein isolate, preferably above about 80 wt %, but also decreases the salt concentration of the final protein isolate after drying. The ability to control the salt concentration of the isolate is important in applications of the isolate where variations in salt concentrations affect the functional and sensory properties in a specific food application.
As is well known, ultrafiltration and similar selective membrane techniques permit low molecular weight species to pass therethrough while preventing higher molecular weight species from so doing. The low molecular weight species include not only the ionic species of the food grade salt but also low molecular weight materials extracted from the source material, such as, carbohydrates, peptides, pigments and anti-nutritional factors, as well as any low molecular weight forms of the protein. The molecular weight cut-off of the membrane is usually chosen to ensure retention of a significant proportion of the protein in the solution, while permitting contaminants to pass through having regard to the different membrane materials and configurations.
Depending on the temperature employed in the concentration step, the concentrated protein solution may be warmed to a temperature of at least about 20° C., and up to about 60° C., preferably about 25° C. to about 40° C., to decrease the viscosity of the concentrated protein solution to facilitate performance of the subsequent dilution step and micelle formation. The concentrated protein solution should not be heated beyond a temperature above which the temperature of &e concentrated protein solution does not permit micelle formation on dilution by chilled water. The concentrated protein solution may be subject to a firer defatting operation, if required, as described in Murray II.
The concentrated protein solution resulting from the concentration step and optional defatting step then is diluted to effect micelle formation by adding the concentrated protein solution into a body of water having the volume required to achieve the degree of dilution desired. Depending on the proportion of canola protein desired to be obtained by the micelle route and the proportion from the supernatant, the degree of dilution of the concentrated protein solution may be varied. With higher dilution levels, in general, a greater proportion of the canola protein remains in the aqueous phase.
When it is desired to provide the greatest proportion of the protein by the nicelle route, the concentrated protein solution is diluted by about 15 fold or less, preferably about 10 fold or less.
The body of water into which the concentrated protein solution is fed has a temperature of less than about 15° C., generally about 3° C. to about 15° C., preferably less than about 10° C., since improved yields of protein isolate in the form of protein micellar mass are attained with these colder temperatures at the dilution factors used.
The dilution of the concentrated protein solution and consequential decrease in ionic strength causes the formation of a cloud-like mass of highly associated protein molecules in the form of discrete protein droplets in micellar form. The protein micelles are allowed to settle to form an aggregated, coalesced, dense, amorphous sticky gluten-like protein micellar mass. The settling may be assisted, such as by centrifugation. Such induced settling decreases the liquid content of the protein micellar mass, thereby decreasing the moisture content generally from about 70% by weight to about 95% by weight to a value of generally about 50% by weight to about 80% by weight of the total micellar mass. Decreasing the moisture content of the micellar mass in this way also decreases the occluded salt content of the micellar mass, and hence the salt content of dried isolate.
The combination of process parameters of concentrating of the protein solution to a protein content of at least about 200 g/L and the use of a dilution factor less than about 15, result in higher yields, often significantly higher yields, in terms of recovery of protein in the form of protein micellar mass from the original meal extract, and much purer isolates in terms of protein content than achieved using any of the prior art procedures (Murray IA, IB and II) referred to above.
The settled isolate, in the form of an amorphous, aggregated, sticky, gelatinous, gluten-like protein mass, termed “protein micellar mass”, or PMM, is separated from the residual aqueous phase or supernatant, such as by decantation of the residual aqueous phase from the settled mass or by centrifugation The PMM may be used in the wet form or may be dried, by any convenient technique, such as spray drying, freeze drying or vacuum drum drying, to a dry form. The dry PMM has a high protein content, in excess of about 100 wt % protein (calculated as Kjeldahl N×6.25), and is substantially undenatured (as determined by differential scanning calorimetry). The dry PMM isolated from fatty oil seed meal also has a low residual fat content, when the procedure of Murray I is employed, which may be below about 1 wt %.
In accordance with one aspect of the invention, particularly as it is applied to canola protein, it has now been found that the supernatant from the PMM formation and settling step contains significant amounts of canola protein, not precipitated in the dilution step. It has not previously been proposed, in the Murray IA, IB and II patents, to attempt to recover additional protein from the supernatant and no observation is made in this prior art as to any potential protein content of the supernatant. In accordance with this aspect of the invention, steps are taken to recover the canola protein from the supernatant.
In such procedure, the supernatant from the dilution step, following removal of the PMM, may be concentrated to increase the protein concentration thereof. Such concentration is effected using any convenient selective membrane technique, such as ultrafiltration, using membranes with a suitable molecular weight cut-off permitting low molecular weight species, including the food grade salt and other non-proteinaceous low molecular weight materials extracted from the source material, to pass through the membrane, while retaining canola protein in the solution. Ultrafiltration membranes having a molecular weight cut-off of about 3000 to 10,000 daltons having regard to differing membranes and configurations, may be used. Concentration of the supernatant in this way also reduces the volume of liquid required to be dried to recover the protein, and hence the energy required for drying. The supernatant generally is concentrated to a protein content of about 100 to 400 g/L, preferably about 200 to about 300 g/L, prior to drying.
The concentrated supernatant may be dried by any convenient technique, such as spray drying, freeze drying or vacuum drum drying, to a dry form to provide a further canola protein isolate. Such further canola protein isolate has a high protein content, usually in excess of about 90 wt % protein (calculated as Kjeldahl N×6.25) and is substantially undenatured (as determined by differential scanning calorimetry). If desired, the wet PMM may be combined with the concentrated supernatant prior to drying the combined protein streams by any convenient technique to provide a combined canola protein isolate. The combined canola protein isolate has a high protein content, in excess of about 90 wt % (calculated as Kjeldahl N×6.25) and is substantially undenatured (as determined by differential scanning calorimetry).
In another alternative procedure, a portion only of the concentrated supernatant may be mixed with at least part of the PMM and the resulting mixture dried. The remainder of the concentrated supernatant may be dried as any of the remainder of the PMM. Further, dried PMM and dried supernatant also may be dry mixed in any desired relative proportions.
By operating in this manner, a number of canola protein isolates may be recovered, in the form of dried PMM, dried supernatant and dried mixtures of various proportions by weight of PMM and supernatant, generally from about 5:95 to about 95:5 by weight, which may be desirable for attaining differing functional and nutritional properties.
As an alternative to dilution of the concentrated protein solution into chilled water and processing of the resulting precipitate and supernatant as described above, protein may be recovered from the concentrated protein solution by dialyzing the concentrated protein solution to reduce the salt content thereof. The reduction of the salt content of the concentrated protein solution results in the formation of protein micelles in the dialysis tubing. Following dialysis, the protein micelles may be permitted to settle, collected and dried, as discussed above. The supernatant from the protein micelle settling step may be processed, as discussed above, to recover further protein therefrom. Alternatively, the contents of the dialysis tubing may be directly dried. The latter alternative procedure is useful where small laboratory scale quantities of protein are desired.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIG. 1 , there is illustrated schematically a flow sheet of one embodiment to the invention. Canola oil seed meal and aqueous extraction medium are fed by line 10 to an extraction vessel 12 wherein the oil seed meal is extracted and an aqueous protein solution is formed. The slurry of aqueous protein solution and residual oil seed meal is passed by line 14 to a vacuum filter belt 16 for separation of the residual oil seed meal which is removed by line 18 . The aqueous protein solution then is passed by line 20 to a clarification operation 22 wherein the aqueous protein solution is centrifuged and filtered to remove fines, which are recovered by line 24 .
The clarified aqueous protein solution is pumped by line 26 through ultrafiltration membrane 28 to produce a concentrated protein solution as the retentate in line 30 with the permeate being recovered by line 32 . The concentrated protein solution is passed into a precipitation vessel 34 containing cold water fed by line 36 . Protein micellar mass formed in the precipitation vessel 34 is removed by line 38 and passed through a spray dryer 40 to provide dry canola protein isolate 42 .
Supernatant from the precipitation vessel 34 is removed by line 44 and pumped through ultrafiltration membranes 46 to produce a concentrated protein solution as the retentate in line 48 with the permeate being removed by line 50 . The concentrated protein solution is passed through a spray dryer 52 to provide further dry canola protein isolate 54 .
As an alternative, the concentrated protein solution in line 48 may be passed by line 56 to mix with the protein micellar mass before the mixture then is dried in spray dryer 40 .
EXAMPLES
Example 1
This Example illustrates the process of the invention.
‘a’ kg of commercial canola meal was added to ‘b’ L of 0.15 M NaCl solution at ambient temperature and agitated for 30 minutes to provide an aqueous protein solution having a protein content of ‘c’ g/L. The residual canola meal was removed and washed on a vacuum filter belt. The resulting protein solution was clarified by centrifugation to produce ‘d’ L of a clarified protein solution having a protein content of ‘e’ S/L.
The protein extract solution or a ‘f’ L aliquot of the protein extract solution was reduced in volume to ‘g’ L by concentration on an ultrafiltration system using ‘h’ dalton molecular weight cut-off membranes. The resulting concentrated protein solution had a protein content of ‘i’ g/L.
The concentrated solution at ‘j’ ° C. was diluted ‘k’ into 4° C. water. A white cloud of protein micelles formed immediately and was allowed to settle. The upper diluting water was removed and the precipitated, viscous, sticky mass (PMM) was recovered from the bottom of the vessel in a yield of ‘l’ wt % of the extracted protein and dried. The dried protein was found to have a protein content of ‘m’ wt % (N×6.25) d.b. The product was given designation ‘n’. The parameters ‘a’ to ‘n’ are outlined in the following Table I:
TABLE I
n
a
b
c
d
e
f
g
h
i
j
k
l
m
CPIA06-13
300
2500
13.0
1160
10.5
(1)
13
30000
303
(2)
1:10
(2)
106.5
BW-AH12-G16-01
225
1500
19.6
(2)
17.5
600
30
3000
245
30
1:15
(2)
104.1
BW-AL016-K15-
1200
8000
14.9
(2)
10.4
400
40
10000
257
30
1:15
46
106.9
01(3)
CPI-A06-33
300
2000
10.8
1800
8.7
(1)
55
30000
217
(2)
1:10
(2)
104.3
A11-04
300
2000
23.2
1772
21.7
1000
52
30000
240
34
1:15
(2)
107.2
Notes:
(1) All the protein extract solution was concentrated
(2) Not determined
(3) The concentrated retentate was diafiltered with 6 volumes of 0.15 M NaCl while holding the volume at 40 L prior to dilution.
Example 2
The process of Example 1 was repeated with the conditions of the procedure being varied. A number of parameters were studied.
(a) Extraction parameters:
The extraction parameters were varied to ascertain their effect on the concentration of protein solution obtained. The results are tabulated in the following Table II:
TABLE II
Extraction
Extraction
Extraction
Concentration of
pH of extraction
Protein
concentration
Temperature
Time
NaCl Solution
solution
concentration
5% w/v
13° C.
30 min
0.15 M
6.4
5.3 g/L
15% w/v
13° C.
30 min
0.15 M
6.2
12.7 g/L
15% w/v
8° C.
30 min
0.15 M
—
6.6 g/L
15% w/v
34° C.
30 min
0.15 M
—
14.6 g/L
15% w/v
22° C.
10 min
0.15 M
5.9
10.5 g/L
15% w/v
13° C.
60 min
0.15 M
5.9
10.6 g/L
10% w/v
15° C.
30 min
0.15 M
—
9.7 g/L
10% w/v
13° C.
70 min
0.15 M
—
9.3 g/L
10% w/v
13° C.
30 min
0.15 M
5.3
9.8 g/L
10% w/v
13° C.
30 min
0.15 M
6.2
10.6 g/L
(b) Dilution parameters:
The dilution parameters were varied to ascertain their effect on yield of PMM from the dilution step. The results are tabulated in the following Table III:
TABLE III
Protein
Dilution Water
Concentration
Temperature
Dilution Ratio
PMM Recovery
206 g/L
4° C.
1:10
51.7%
258 g/L
4° C.
1:10
61.8%
283 g/L
4° C.
1:10
42.6%
230 g/L
15° C.
1:10
4.5%
249 g/L
4° C.
1:5
40.4%
249 g/L
4° C.
1:3
30.7%
Example 3
This Example illustrates the effect of dilution water temperature on the yield of product protein isolate.
1200 kg of commercial canola meal was added to 8000 L of 0.15 M NaCl solution at ambient temperature and agitated 30 minutes to provide an aqueous protein solution having a protein content of 17.4 g/L. The residual canola meal was removed and washed on a vacuum filter belt. The resulting protein solution was clarified by centrifugation to produce 7464 L of a clarified protein solution having a protein content of 14.8 g/L
The protein extract solution was reduced in volume by concentration on an ultrafiltration system utilizing 3,000 dalton membranes. The resulting concentrated protein solution had a protein content of 230 g/L.
A 50 ml aliquot of the concentrated solution was warmed to 30° C. then diluted 1:10 into 15° C. tap water. A slight white cloud of very small micelles formed and was allowed to settle. The upper diluting water was removed leaving a very small amount of precipitate. The precipitate only represented 4.5 wt % of the protein in the 50 ml aliquot of the concentrated solution instead of a typical 50 wt % recovery achieved when diluted into 4° C. tap water. The 50 ml aliquot was taken from the batch with the designation BW-AH012-H14-01A. The data from this Example are also presented in Table m above with respect to the dilution ratio.
Example 4
This Example shows the effect of temperature of concentrated solution on dilution yield.
1200 kg of commercial canola oil seed meal was added to 8000 L of 0.15 M NaCl solution at ambient temperature and agitated for 30 minutes at 13° C. to provide an aqueous protein solution having a protein content of ‘a’ g/L. The residual canola meal was removed and washed on a vacuum filter belt. The resulting protein solution was clarified by centrifugation to produce a clarified solution having a protein content of ‘b’ g/L.
The clarified protein solution or a ‘c’ aliquot of the protein extract solution was reduced in volume to ‘d’ L on a ultrafiltration system using a ‘e’ dalton molecular weight cut-off membrane. The resulting concentrated protein solution had a protein content of ‘f’ g/L. The lots were given designation ‘g’.
The parameter ‘a’ to ‘g’ are given in the following Table IV:
TABLE IV
g
BW-AL011-J16-01A
BW-AL017-D11-02A
a
24.4
26.3
b
20.3
18.0
c
(1)
2000
d
152
e
3000
5000
f
287
285.9
Note:
(1) All the protein extract solution was concentrated.
50 ml retentate aliquots of lot BW-AL011-J16-01A were warmed to 30° C. and 60° C. before being diluted 1:10 into 4° C. water. In each case, a white cloud of protein micelles formed immediately and was allowed to settle. The upper diluting water was removed and the precipitated, viscous, sticky mass (PMM) was dried. The PMM was recovered from each experiment and the yield of the dilution step was calculated. In the case of the retentate temperature being 30° C., the protein recovery was 57.1 wt %, while for 60° C., the yield was 23.7 wt %.
5 ml retentate aliquots of lot BW-AL017-D11-02A were warmed to various temperatures between 30° C. and 60° C. and then diluted at dilution ratio of 1:10 or 1:15 into 4° C. water. In each case, a white cloud of protein micelles formed immediately and was allowed to settle. The upper diluting water was removed and the precipitated, viscous, sticky mass (PMM) was dried. The PMM was recovered from each experiment and the yield of the dilution step was calculated. The results obtained appear in the following Table V:
TABLE V
Retentate Temperature
Dilution Ratio
PMM Yield
30° C.
1:10
49%
40° C.
1:10
49
50° C.
1:10
47
60° C.
1:10
35
30° C.
1:15
51
40° C.
1:15
51
50° C.
1:15
39
60° C.
1:15
39
As may be seen from this Table, higher yields are obtained at moderately elevated temperatures while higher elevated temperatures tend to reduce yields.
Example 5
This Example illustrates the preparation of further canola protein isolates using various combinations of parameters and additionally including treatment with powdered activated carbon.
‘a’ kg of commercial canola meal was added to ‘b’ L of 0.15 M NaCl solution at ambient temperature and agitated ‘e’ minutes to provide an aqueous protein solution having a protein content of ‘d’ g/L. The residual canola meal was removed and washed on a vacuum filter belt. The resulting protein solution was clarified by centrifugation to produce a clarified protein solution having a protein content of ‘e’ g/L.
‘f’ wt % powdered Activated Carbon (PAC) was added to the clarified solution. The suspension was mixed for 15 minutes, following which the PAC was removed by filtration, resulting in ‘g’ L of a ‘h’ g/L extract.
A ‘i’ L aliquot of the protein extract solution from the PAC treatment step was reduced in volume to ‘j’ L on an ultrafiltration system using a 30,000 dalton molecular weight cut-off membrane. The resulting concentrated protein solution had a protein content of ‘k’ g/L.
The concentrated solution at ‘l’ ° C. was diluted 1: ‘m’ into 4° C. tap water. A white cloud formed immediately and was allowed to settle. The upper diluting water was removed and the precipitated, viscous, sticky mass was dried. The dried protein which was formed had a protein content of ‘n’ wt % protein (N×6.25 d.b.). The overall protein recovery i.e. the average of dried protein isolate expressed as a percentage of the protein solubilized in the extraction step, was ‘o’ wt %. The product was given designation CPI ‘p’.
The specific parameters “a” to “p” for these different samples of protein product are set forth in the following Table VI:
TABLE VI
p
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
A07-15
150
1000
30
14.0
13.1
2
700
8.9
460
21
246
30
10
103.5
44
A07-22
150
1000
120
13.0
12.3
4
800
8.2
800
9
490
20
5
106.9
(1)
A08-02
300
2000
300
14.0
14.5
0.06
1300
13.8
480
6
421
25
5
105.8
(1)
A10-13
300
2000
45
28.6
24.9
1
2150
22.7
1000
80
176
20
10
109.2
(1)
Note:
(1) not determined.
The effect of the addition of powdered activated carbon on colour of canola protein isolate is shown in Example 7 below.
Example 6
This Example illustrates an embodiment of the invention, wherein water was used in the extraction stage and salt was subsequently added.
150 kg of commercial canola meal was added to 1000 L of water at 13° C., agitated for 30 minutes resulting in a protein solution with a concentration of 4.5 g/L. The residual canola meal was removed and washed on a vacuum filter belt. The aqueous protein solution was clarified by centrifugation producing 1100 L of a 3.8 g/L extract.
Powdered activated carbon (PAC) was precoated on filter pads before the clarified solution was filtered producing 1000 L of a 3.2 g/L extract.
Sodium chloride was added to the latter protein solution to a concentration of 0.15M. The volume of the protein solution was reduced to 10 L on an ultrafiltration system using 30,000 dalton membranes. The concentrated solution had a protein content of 292 g/L. An aliquot of the concentrated protein solution was warmed to 30° C. prior to dilution 1:3 into 4° C. water.
A white cloud formed immediately and was allowed to settle. The upper diluting water was removed and the precipitated, viscous, sticky mass (PMM) was dried. The dried canola protein isolate, given identification CPI A07-18, had a protein content of 96 wt % protein (N×6.25). The recovery of protein was 59 wt % of the protein originally extracted.
Example 7
This Example provides a comparison of the colour of certain canola protein isolates produced herein in comparison to spray dried egg white, conventional soy protein isolate and products produced according to Murray H.
Samples of protein isolate were evaluated for lightness (L) and chromaticity (a and b) using a Minolta colourimeter. In the L a b colour space, the value moves from 0 to 100, with 100 being white and 0 being black The chromaticity coordinates, a and b, both have maximum values of +60 and −60, +a being the red direction, −a being the green direction, +b being the yellow direction and −b being the blue direction.
The following Table VII sets forth the results obtained:
TABLE VII
Sample
L
a
b
Comments
Egg White
90.34
−2.73
21.43
Soy Protein
85.10
−0.906
14.67
The a and b values are not as close
Isolate
to egg white as PAC treated CPI
CPI A07-15
82.77
−2.13
22.98
NaCl extraction with high (2%)
(Example 5)
PAC
CPI A07-18
82.80
−2.69
25.19
Water extraction with PAC
(Example 6)
CPI A06-33
75.60
0.404
26.51
NaCl extraction without PAC
(Example 1)
CPI A08-02
80.04
−2.87
23.37
NaCl extraction with low (0.06%)
(Example 5)
PAC
Murray II
65.81
0.962
18.27
Relatively dark product
The results set forth in Table VII show the beneficial effect on colour, namely more white, less yellow, by the use of powdered activated carbon.
Example 8
This Example illustrates the preparation of flier canola protein isolate including protein recovered from supernatant.
‘a’ kg of commercial canola meal was added to ‘b’ L of 0.15 M NaCl solution at ambient temperature and agitated for 30 minutes to provide an aqueous protein solution having a protein content of ‘c’ g/L. The residual canola meal was removed and washed on a vacuum filter belt. The resulting protein solution was clarified by centrifugation to produce a clarified protein solution having a protein content of ‘d’ g/L followed by the addition of 1 wt % Powdered Activated Carbon (PAC).
The suspension was mixed for 15 minutes, following which the PAC was removed by filtration, resulting in ‘e’ L of a ‘f’ g/L extract.
A ‘g’ L aliquot of the protein extract solution from the PAC treatment step was reduced in volume to ‘h’ L on an ultrafiltration system using 30,000 dalton molecular weight cut-off membranes. The resulting concentrated protein solution had a protein content of ‘i’ g/L.
The concentrated solution at ‘j’ ° C. was diluted 1: ‘k’ into 4° C. water. A white cloud formed immediately and was allowed to settle. The upper diluting water was removed and was reduced in volume by ultrafiltration using 3000 dalton molecular weight cut-off membranes by a volume reduction factor of ‘l’. The concentrate was added to the precipitated, viscous, sticky mass and the mixture was dried. The dried protein mixture which was formed had a protein content of ‘m’ wt % of protein (N×6.25). The product was given designation CPI ‘n’.
The specific parameters ‘a’ to ‘n’ for two different samples of protein product are set forth in the following Table VIII:
TABLE VIII
n
a
b
c
d
e
f
g
h
i
j
k
l
m
A10-04
300
2000
28.4
27.6
1330
16.3
200
18
186
28
10
11
100.3
A10-05
300
2000
27.7
21.9
1320
21.9
300
20
267
27
15
21
102.3
Example 9
This Example further illustrates the preparation of further canola protein isolate including protein recovered from supernatant without PAC treatment
‘a’ kg of canola meal was added to ‘b’ L of 0.15 M NaCl solution at a temperature of 20° C. and agitated for 30 minutes to provide an aqueous protein solution having a protein content of ‘c’ g/L. The resulting canola meal was removed and washed on a vacuum filter belt. The resulting protein solution was clarified by centrifugation and filtration to produce a clarified protein solution having a protein content of ‘d’ g/L.
The protein extract solution or a ‘e’ L aliquot of the protein extract solution was reduced in volume on n ultrafiltration system using membranes having a molecular weight cut-off of ‘f’ daltons. The resulting concentrated protein solution had a protein content of ‘g’ g/L.
The concentrated solution at ‘h’ ° C. was diluted ‘i’ into ‘j’ ° C. water. A white cloud immediately formed and was allowed to settle. The upper diluting water was removed and concentrated by ultrafiltration using 3000 dalton molecular weight cut-off membranes to provide a concentrated supernatant having a protein content of ‘k’ g/L. The concentrate was added to the precipitated, viscous, sticky mass and the mixture dried.
The dried protein mixture was found to have a protein content of ‘l’ wt % (N×6.25). The yield of canola protein isolate from the protein solution extract was ‘m’ wt %. The product was given designation ‘n’.
The specific parameters ‘a” to ‘n’ for two different samples of protein product are set forth in the following Table IX:
TABLE IX
n
BW-AL11-I21-01A
A11-01
a
1200
300
b
8000
2000
c
24.5
23.7
d
17.8
20.7
e
(1)
400
f
3000
30,000
g
284.7
200.2
h
31
32
i
1:10
1:15
j
8
4
k
279.0
104.7
l
100.2
102.8
m
68.1
(2)
Note:
(1) All the protein extract solution was concentrated
(2) not determined
Example 10
This Example illustrates extraction of the canola protein meal at a relatively high pH and recovery of protein from supernatant.
150 kg of commercial canola meal was added to 2000 L of 0.15 M NaCl having a pH adjusted to 9.5 by the addition of sodium hydroxide at ambient temperature, agitated for 30 minutes to provide an aqueous protein solution having a protein content of 13.2 g/L. The residual canola meal was clarified by centrifugation and filtration to produce 1210 L of a clarified protein solution having a protein content of 12.1 g/L.
The pH of the clarified protein solution was adjusted to 6.2 by the addition of hydrochloric acid. A 900 L aliquot of the protein extract solution was reduced in volume to 50 L by concentration on an ultrafiltration system using 3000 dalton molecular weight cut-off membranes. The resulting concentrated protein solution had a protein content of 276.2 g/L.
The concentrated solution at 30° C. was diluted 1:15 into 4° C. water. A white cloud formed immediately and was allowed to settle. The upper diluting water was removed and 390 L of this supernatant were concentrated by 24 L by ultrafiltration using 3000 dalton molecular weight cut-off membranes to provide a concentrated supernatant having a protein content of 149.0 g/L. The concentrate was added to the precipitated, viscous, sticky mass and the mixture dried.
The dried protein mixture was found to have a protein content of 103.3 wt % (N×6.25). The yield of canola protein isolate from the protein solution extract was 48.3 wt %. The product was given designation BW-AL017-D08-02A.
Example 11
This Example illustrates the preparation of canola protein isolate by processing of supernatant.
‘a’ kg of commercial canola meal was added to ‘b’ L of 0.15 M NaCl solution at ambient temperature and agitated for 30 minutes to provide an aqueous protein solution having a protein content of ‘c’ g/L. The residual canola meal was removed and washed on a vacuum filter belt. The resulting protein solution was clarified by centrifugation to produce a clarified protein solution having a protein content of ‘d’ g/L.
The clarified protein solution was reduced in volume on an ultrafiltration system using 3,000 dalton molecular weight cut-off membranes. The resulting concentrated solution had a protein content of ‘e’ g/L.
The concentrated solution at ‘f’ ° C. was diluted ‘g’ into 4° C. water. A white cloud formed immediately and was allowed to settle. The upper diluting water was removed and the precipitated, viscous, sticky mass (PMM) was recovered from the bottom of the vessel and dried. The dried protein was found to have protein content of ‘k’ wt % (N×6.25) d.b.
The removed upper diluting water was reduced in volume by ultrafiltration using 3,000 dalton molecular weight cut-off membranes to a protein concentration of ‘i’ g/L. The concentrate then was dried. The dried protein which was formed had a protein content of ‘j’ wt % (N×6.25). The product was given designation ‘l’.
The specific parameters ‘a’ to ‘l’ for two different samples of protein product are set forth in the following Table X:
TABLE X
l
AL016-J24
AL011-J16-01A
a
1200
1200
b
8000
8000
c
22.7
24.4
d
16.9
20.3
e
281
287
f
37
28
g
1:10
1:10
h
(2)
101.9
i
(3)
265
j
103.9
101.5
k
(2)
101.6
Note:
(1) All the protein extract solution was concentrated
(2) Not determined
(3) The supernatant was concentrated by a volume reduction factor of 16.
Example 12
This Example illustrates application of the process of the invention to cold pressed canola meal and the recovery of additional protein from the supernatant.
50 kg of canola meal was pressed and 13 L of oil recovered. 30 kg of the resulting crushed meal was added to 300 L of 0.15M NaCl solution at 20° C. and the mixture was agitated for 40 minutes, followed by a thirty minute settling period, 200 L of aqueous protein solution were obtained having a protein content of 19.5 mg/ml.
The aqueous protein solution was chilled to 4° C. and refrigerated at that temperature for 16 hours, to permit fat present in the meal and extracted in the extraction step, to separate, according to the procedure of Murray II. The resulting fat layer was removed from the surface of the aqueous protein solution. The remaining aqueous protein solution was filtered through a filter press having a 20 μm filter pad to remove remaining particles of hull and cell wall material as well as residual particles of fat. 200 L of filtrate with a protein content of 14.6 mg/ml were obtained.
The aqueous protein solution was reduced in volume to 10.5 L by concentration on an ultrafiltration system using 10,000 dalton molecular weight cut. off membranes. The resulting concentrated protein solution had a protein content of 200 g/L, which represented a yield of 67 wt % of the protein originally extracted from the canola meal. The resulting 10.5 L solution was again chilled to 4° C. and refrigerated at this temperature for 16 hours. The solution was then centrifuged at 10,000×g for five minutes and the separated fat removed from the concentrated protein solution.
The protein solution was warmed to 30° C. and was added to water at 4° C. at a dilution ratio of 1:9. Following overnight settling, 85 L of supernatant was decanted leaving approximately 9 L of precipitated, viscous, sticky mass (PMM). The PMM was further concentrated by centrifugation at 10,000×g for 5 minutes and an aliquot of the centrifuged PMM was freeze dried to determine its protein content The freeze dried PMM was found to have a protein content of 105.5 wt % (N×6.25).
The supernatant from the PMM formation step was concentrated to 11 L by concentration on a ultrafiltration system using 10,000 dalton molecular weight cut-off membranes. This latter concentrated solution had a protein concentration of 89.7 mg/ml. An aliquot of this concentrated solution was freeze dried to determine the protein content. The freeze-dried protein was found to have a protein content of 101.7 wt % (N×6.25).
The overall yield of protein as PMM and recovered from the supernatant from the protein extracted from the canola meal was 50 wt %.
Example 13
This Example illustrates application of the process of the invention to high erucic acid rapeseed.
35 kg of commercial high erucic acid rapeseed meal was added to 350 L of 0.3 M NaCl solution (10% w/v) at 15° C. and agitated for one hour to provide an aqueous protein solution having a protein content of 7.71 g/L. A second run under the same conditions produced an aqueous protein solution having a protein content of 7.36 g/L. The extract solutions were decanted and clarified by filtration though 20 n filter pads to remove residual meal and to provide a total filtrate volume of 550 L.
The filtrate then was concentrated to 9 L using a hollow fibre ultrafiltration system having 10,000 dalton molecular cut-off membranes The resultant concentrated protein solution had a protein content of 232 g/L.
The concentrated protein solution, at a temperature of 30° C., was then diluted 1:9 into 4° C. water. A white cloud immediately formed and was allowed to settle for 16 hours at 4° C. 80 L of supernatant was decanted and was reduced in volume by diafiltration concentration to a volume of 7 L of concentrated supernatant having a protein content of 47.7 g/L.
The settled viscous sticky mass (PMM) was collected and freeze dried. A one liter portion of the concentrated supernatant was freeze dried. 1393 g of freeze dried PMM was obtained from the process having a protein content of 106 wt % (N×6.25). 1 L of freeze dried concentrated supernatant yielded 67 g, so that the 7 L of concentrated supernatant contained 469 g of dried protein, for an overall protein yield from the protein extracted from the oil seed meal of 47 wt %. The freeze-dried concentrated supernatant had a protein content of 83 wt % (N×6.25) so that a mixture of PMM and protein from concentrated supernatant has a protein content of 102 wt % (N×6.25) on a dry weight basis.
Example 14
This Example illustrates application of the invention to mustard seed.
75 g of commercial mustard seed meal was added to 750 ml of 0.15 M NaCl solution (15% w/w) at 20° C. and agitated for 30 minutes. The extraction slurry was centrifuged at 10,000×g for 10 minutes to separate the spent meal from the extracted protein. The resulting 500 ml of protein solution having a protein content of 18.05 mg/ml was then filtered through Whatman #4 filters in order to further clarify the solution.
The clarified solution was concentrated to 27 ml on a Millipore mini-ultrafiltration stirred cell system using 10,000 molecular weight cut-off membranes. The resulting concentrated protein solution had a protein concentration of218 g/L.
22.2 ml of the total 27 ml of concentrated protein solution, at a temperature of 30° C., was then diluted 1:9 into 4° C. tap water. A white cloud immediately formed and was allowed to settle for 16 hours at 4° C. 200 ml of supernatant was decanted.
The settled viscous, sticky mass (PMM) was collected and centrifuged at 10,000×g for 5 minutes to reduce the moisture content of the pellet, which then was freeze dried. 4.48 g of freeze-dried pellet was obtained, representing a yield of protein in the freeze-dried pellet from the protein in the protein extracted from the oil seed meal was 50 wt % (if the entire 27 ml of retentate had been diluted, the final yield is extrapolated to be approximately 60 wt %). The freeze-dried PMM obtained from the process had a protein content of 103 wt % (N×6.25).
Example 15
This Example illustrates application of the process of the invention to non-GMO canola.
450 g of non-GMO canola meal was added to 3 L of 0.15 M NaCl solution (15% w/w) at 20° C. and agitated for 30 minutes to provide an aqueous protein solution having a protein content of 8.08 g/L. The mixture was allowed to stand for 30 minutes to permit residual meal and protein solution to separate. The protein solution was decanted, centrifuged for 10 minutes at 10,000×g and filtered through Whatman #4 filter paper to further clarify the solution.
The filtrate then was concentrated to a volume of 17 ml using a hollow fibre ultrafiltration system having 10,000 dalton molecular cut-off membranes. The resultant concentrated protein solution has a protein content of 205 g/L.
A 14 ml sample of the retentate, at a temperature of 30° C., was then diluted 1:9 into 4° C. tap water. A white cloud immediately formed and was allowed to settle. The supernatant was decanted and the settled viscous sticky mass (PMM) was collected and freeze-dried. 2.3 g of freeze-dried PMM was obtained from the process having a protein content of 103 wt % (N×6.25).
The overall yield of protein with respect to the protein extract from the oil seed meal was 41 wt %. If the entire 17 ml of retentate had been diluted approximately 2.66 g of dried protein would have been recovered for a yield of 46 wt %.
Example 16
This Example illustrates recovery of canola protein isolate by a dialysis procedure.
‘a’ kg of commercial canola meal was added to ‘b’ L of 0.15 M NaCl solution at ambient temperature and agitated for 30 minutes to provide an aqueous protein solution having a protein content of ‘c’ g/L. The residual canola meal was removed and washed on a vacuum filter belt. The resulting protein solution was clarified by centrifugation to produce ‘d’ L of a clarified protein solution having a protein content of ‘e’ g/L.
A ‘f’ aliquot of the protein extract solution was reduced in volume to ‘g’ L by concentration on an ultrafiltration system using ‘h’ dalton molecular weight cut-off membranes. The resulting concentrated solution had a protein content of ‘i’ g/L. The retentate was given designation ‘j’. The parameters ‘a’ to ‘j’ are outlined in the following Table A:
TABLE XI
j
BW-AL017-D17-02A
BW-AL017-D22-02A
a
150
150
b
1004
1003
c
25.1
27.1
d
1080
1132
e
18.0
16.5
f
710
1092
g
22.5
31.5
h
5000
5000
i
291.6
362.5
3.5 L of retentate from BW-AL017-D17-02A was dialyzed in 120 L of 4° C. water. The water was changed daily for several days and running water was used for the last two days. The conductivity of the retentate dropped from 6.89 millisiemens (ms) to 0.32 ms. As the conductivity dropped, micelles began to form in the retentate. At the completion of the dialysis, a large amount of PMM was present at the bottom of each dialysis tube. The PMM was recovered and dried. The canola protein isolate had a protein content of 103.0 wt % d.b.
The procedure was repeated with the retentate BW-AL017-D22-02A except that the dialysis was carried out in 60° C. water. As the conductivity decreased, the solution became cloudy but very little micelle formation occurred. Once the dialyzed solution was cooled to 10° C., micelle formation occurred. The resulting PMM, when dried, had a protein content of 106 wt % of d.b.
SUMMARY OF DISCLOSURE
In summary of this disclosure, the present invention provides a novel procedure for isolating protein from oil seeds in improved yields and protein content than has previously been achieved. Modifications are possible within Me scope of this invention. | Oil seed protein isolates, particularly canola protein isolate, are produced at a high purity level of at least about 100 wt % (N×6.25) by a process wherein oil seed protein is extracted from oil seed meal, the resulting aqueous protein solution is concentrated to a protein content of at least about 200 g/L and the concentrated protein solution is added to chilled water having a temperature below about 15° C. to form protein micelles, which are settled to provide a protein micellar mass (PMM). The protein micellar mass is separated from supernatant and may be dried. The supernatant may be processed to recover additional oil seed protein isolate by concentrating the supernatant and then drying the concentrated supernatant, to produce a protein isolate having a protein content of at least about 90 wt %. The concentrated supernatant may be mixed in varying proportions with at least part of the PMM and the mixture dried to produce a protein isolate having a protein content of at least about 90 wt %. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to the measurement of Doppler frequency and, more particularly, to the modification of the Doppler power spectrum for extraction of Doppler data therefrom.
The measurement of Doppler frequency is often accomplished by one or more filters which signal the magnitude of the frequency, or by means of timing circuits which provide the time elapsed by a specified number of cycles of the Doppler signal. Such systems are intended for use primarily in a situation providing clear unambiguous Doppler signals.
A problem arises in the case of reverberant and nonlinear radiation transmissive media, such as the ocean which is transmissive of radiant sonic energy, in that such a medium with its multifarious reflecting boundaries, such as mud and rock, alters a Doppler signal. The altered signal is characterized by a broadened spectrum which is inherently ambiguous to Doppler frequency measurement, the spectrum providing many possible values of Doppler frequency which derogate from an accurate measurement of the Doppler frequency.
SUMMARY OF THE INVENTION
The foregoing problem is overcome and other advantages are provided by a system for measuring Doppler frequency in a medium propagative of radiant energy and which, in accordance with the invention, utilizes a receiver providing a set of samples of a Doppler signal received during a predetermined interval of time. The system includes a Fourier transformer coupled to a logarithmic circuit for obtaining the logarithm of the power spectrum of the set of samples. The logarithms are then weighted by orthogonal factors, such as the first few terms of a Legendre series, in a weighting circuit and combined in an arithmetic circuit to give a numerical result which represents Doppler frequency as well as relative speed between the receiver and points of reflection of the radiant energy within the medium.
The theoretical support for the invention is based upon the observation that empirical data of received Doppler spectra of reverberant media, such as the ocean, with nonlinear reflectors, such as air bubbles and mud, has the form of a continuous spectrum approximately centered about a nominal value f o of the Doppler frequency, the nominal value being the value of Doppler frequency seen by a Doppler tracking filter of the prior art. This spectrum can be portrayed as a function of frequency by a mathematical formulation, namely, an exponential relationship in which the exponent is a summation of terms of an orthogonal series, for example, a Legendre series, wherein the independent variable is proportional to the frequency. Thus the power spectral density S(ν) of the Doppler spectrum is given by ##EQU1## WHERE P n is the n th polynomial of the Legendre series α 0 = lnS(ν=0)-π(ν c 2 /W 2 ) - (π/3)(ν m 2 /W)
α 1 = 2π(ν m ν c /W 2 )
α 2 = (-2π/3)(ν m 2 /W 2 ) for a Gaussian shaped spectrum
and
ν = f-f o
|ν| = ≦ ν m
and wherein
f is a frequency of the Doppler spectrum;
f o is the nominal value or estimate of the Doppler frequency;
subscript c denotes the frequency of the peak value of the Doppler spectrum;
subscript m denotes a maximum value of frequency deviation at either side of f o , these being the upper and lower edges of a Doppler spectrum centered on f o ;
W is the effective noise bandwidth of the Doppler signal;
P n is the n th term of the Legendre series.
Comparing the mathematics with the structural components of the invention, it is seen that the logarithmic circuitry retrieves the exponent. Multiplication of the terms of an orthogonal series by the terms of an orthogonal series, this being accomplished in the weighting circuitry, produces nonzero products for commonly indexed terms of the series. It is noted that the Fourier series is also an orthogonal function. Combination of the products by the arithmetic circuitry to produce the Doppler frequency, namely f c , is accomplished by a formulation, to be disclosed hereinafter, which may be varied in accordance with sea state and ocean bottom characteristics to optimize the accuracy of the system.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned aspects and other features of the invention are explained in the following description taken in connection with the accompanying drawings wherein:
FIG. 1 is a stylized view of a ship carrying a sonar system embodying the invention, the drawing showing the radiation of four beams of sonic energy through the water of the ocean;
FIG. 2 is a block diagram of an electronics unit shown in FIG. 1 and including sonar receivers constructed in accordance with the invention;
FIG. 3 is a block diagram of a receiver of FIG. 2 showing a Fourier transformer, a logarithmic unit, and a weighting unit in accordance with the invention, the Figure including a graph of the Doppler spectrum showing the aforementioned mathematical terms f o and f c ;
FIG. 4 is a schematic diagram of a vector summation unit of FIG. 2;
FIG. 5 is a block diagram of a sampler of FIG. 3; and
FIG. 6 is a timing diagram useful in explaining the operation of the receiver of FIG. 3 and the sampler of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is seen a stylized view of a sonar system 20 embodying the invention and including a set of four transducers 22 which are symmetrically positioned about a vertical axis and inclined thereto at an angle of approximately 25 degrees for directing four beams 24 of sonic energy in diverging directions from the hull of a ship 26 and downwardly towards the bottom 27 of the ocean 28. The transducers 22 are secured to the hull of the ship 26 and are coupled via lines 30 to an electronics unit 32, the figure also showing a display 34 in the bridge of the ship 26 and coupled to the electronics unit 32 by line 36. Individual ones of the transducers 22 are further identified by the numerals 1-4 of which the transducers #1 and #2 are positioned forward of the transducers #3 and #4, the transducers #1 and #3 being on the starboard side while the transducers #2 and #4 are on the port side of the ship 26.
FIG. 1 also shows wavy lines representing the transmission of sonic energy signals towards the bottom 27 and echoes of sonic energy therefrom. Echoes are also received from bubbles of air within the water as well as from rocks and mud on the bottom of 27, the frequency spectrum of the echo being modified from that of the transmitted signal by virtue of interaction of the sonic energy with the air bubbles, the rocks, or the mud. In addition, the spectrum of the echo has a Doppler shift in frequency imparted thereto by virtue of relative motion between the ship 26 and the air bubbles, the rocks, and the mud.
Referring to FIG. 2, the block diagram shows the components of the electronics unit 32 and its interconnections by the lines 30 and 36 to the transducers 22 and the display 34, of FIG. 1. The electronics unit 32 comprises an oscillator 38, a timer 40, a modulator 42, an amplifier 44, transmit-receive circuits 46, receivers 48, and a vector summer 50. The amplifier 44 is coupled to each of the transmit-receive circuits 46 whereby electrical energy is coupled to each of the transducers 22 for the radiation of sound therefrom, the electrical signals generated by the transducers 22 in response to the reception of sonic echoes being coupled via individual ones of the transmit-circuits 46 to individual ones of the receivers 48. The transmitted signal comprises, in a preferred embodiment of the invention, a pulsed sinusoid wherein the sinusoid frequency is provided by the oscillator 38 and the pulsations of the sinusoid are provided by the modulator 42, the modulator 42 being an amplitude modulator which pulses an output signal of the oscillator 38 in response to timing signals applied via line 52 from the timer 40. If desired, oscillations of the oscillator 38 may be synchronized to the operation of the modulator 42 by timing signals on line 54 from the timer 44 locking the oscillations to the timing of the modulator 42. An electrical signal produced by the modulator 42 is amplified by the amplifier 44 and then coupled to the transducers 22 for the transmission of the sonic energy therefrom. Also shown in FIG. 2 are timing signals via terminals T for synchronizing the operation of the receivers 48 to the transmission of sonic energy by the transducers 22, the figure also showing clock pulse signals coupled by terminal C to the display 34 and the summer 50 for the synchronization of their operations to that of the receivers 48.
Referring now to FIG. 3, there is seen a block diagram of one of the four receivers 48 of FIG. 2 with its interconnections to the display 34 via line 56, from the transmit-receive circuit 46 via line 58, to the summer 50 via line 60, and its interconnections to the timer 40 via the terminal T. The receiver 48 comprises an amplifier 62, an envelope detector 64, a range tracker 66, a gate 68, a sampler 70, a storage unit 72, a Fourier transformer 74, a squaring unit 76, a logarithmic unit 78, a multiplier 80, a storage unit 82, a memory 84, an arithmetic unit 86, and a summer 87.
The amplifier 62 receives echo signals from a transducer 22 via line 58 and amplifies the signals to a suitable value for operating the envelope detector 64 and the sampling circuit 70. In addition, the amplifier 62 includes a bandpass filter having a bandwidth sufficiently narrow to exclude spectral components of noise lying outside the spectrum of the signal on line 58. The detector 64 detects the envelope of the signal coupled thereto from the amplifier 62, the detector 64 providing a pulse signal with said envelope on line 56 to the display 34 and to the range tracker 66. Terminals T1-T10 are seen fanning out of terminal T, the timing signal of terminal T1 being utilized for driving the range tracker 66, the terminals T2-T10 being utilized for other components of the receiver 48 as will be described below. Thereby the operation of the components of the receiver 48 are synchronized with the operation of the system 20 of FIG. 2.
The tracker 66 tracks the occurrences of the pulse signals on line 56 and provides a gate signal on line 88, such as are presented by the waveform 90, for operating the gate 68 to couple signals via line 91 to the sampler 70 from a time immediately preceding the occurrence of the echo signal on line 58 to a time immediately after the occurrence of the echo signal on line 58. Thereby a signal from the output terminal of the amplifier 62 can only be coupled to the sampler 70 during an interval of time when the echo signal on line 58 is anticipated. Accordingly, the receiver 48 is rendered insensitive to signals other than echoes emanating from the reflecting objects in the ocean 28 of FIG. 1 at a predetermined range from the ship 26. A knob 92, attached to the tracker 66, is operated manually during an acquisition mode for locking the tracker 66 onto an echo selected from echoes presented on the display 34 via the line 56.
In accordance with the invention, the echo signal coupled to the sampler 70 is sampled in response to timing signals applied thereto at terminal T2 from the timer 40, the sampler 70 including circuitry for converting inphase and quadrature analog samples to digital samples represented by digital numbers. The sampler 70 also comprises a phase locked loop, as will be described hereinafter, for offsetting the echo signal in frequency by f o , the nominal Doppler frequency, so that the samples relate to the Doppler spectrum centered about f o . During the duration of the waveform 90, the sampler 70 is operated at successive instances of time by signals at terminal T2 to provide a set of the digital samples of the echo signal, these samples being coupled to the storage unit 72 via line 106 in response to strobing signals provided at terminal T3. The nominal Doppler frequency appears on line 107.
In accordance with the invention, the set of stored complex numbers in the storage unit 72 is converted by the transformer 74 to a corresponding set of digital numbers representing the spectral lines of the Fourier transformation of the set of numbers in the storage unit 72. In response to timing signals at terminals T4 and T5, each of the digital numbers representing the spectral lines is coupled from the transformer 74 to the squaring unit 76. Thus, the set of output digital signals of the squaring unit 76 represents the power spectrum of the signal coupled by the gate 68. In response to timing signals at the terminals T5 and T6, the digital numbers representing the power spectral lines of the squaring unit 76 are coupled to the logarithmic unit 78 which provides an output signal, namely, a set of digital numbers each of which represents respectively the logarithm of an individual power spectral line.
The weighting of the logarithm by the Legendre polynomials is accomplished by the multiplier 80 and the memory 84, the memory 84 storing digital numbers which serves as weighting coefficients, the numbers being coupled by the lines identified by the legends P1-P4 representing the Legendre polynomials, these lines seen fanning into the line 108. The output signal of the logarithmic unit 78 and the weighting factors on line 108 are multiplied by the multiplier 80 in response to timing signals on terminals T7 and T8 to produce a set of weighted digital numbers. In response to timing signals at terminal T9, the weighted digital numbers are stored in the storage unit 82 in a format of four sets of complex numbers, the four sets corresponding to the situation of the forgoing example in which four terms of the Legendre polynomial are utilized. If five terms or six terms of the polynomial are utilized, then, correspondingly, five or six sets of weighted complex numbers appear in the storage unit 82. The stored values are represented via the lines 110 which show, by way of example, the P1 products, the P2 products, the P3 products and the P4 products. Each of these sets of products may be obtained by multiplying the set of digital numbers from the logarithmic unit 78 by a term of the Legendre polynomials.
The arithmetic unit 86 comprises four summers 112, 114, 116 and 118, a calculator 120, and multipliers 122, 124, 126 and 128 for coupling the individual ones of the summers 112, 114, 116 and 118 to the calculator 120. In response to timing signals at terminals T9 and T10, the summer 112 receives the P1 products from the storage unit 82 and sums them together. The resultant sum and a factor on line 130 are then multiplied together by the multiplier 122 to produce an estimate of a term of the Legendre polynomial, this estimate being presented to the calculator 120. The multiplying factors for each of the multipliers 122-128 are coupled by the line 130 from the memory 84, the formula for the factors being presented in the figure alongside the line 130. The formula has the terms n and L wherein n represents the index of the Legendre coefficient, thus n=l for the P1 products. The term L represents the number of samples taken by the sampler 70 during the duration of the waveform 90 on line 88, the waveform 90 and a set of L samples being shown in the graph 132.
As explained hereinbefore, due to the orthogonality of the Legendre polynomials, multiplication of the P1 products, or other set of products of the storage unit 82, by a term of the Legendre polynomial would result in products of zero value while a nonzero value is obtained only in the case wherein the two factors being multiplied have a common index. However, due to the presence of noise on the samples of the sampler 70 as well as variations in the Doppler signals received at the transducers 22 of FIG. 2 from the idealized modeling of such signals, nonzero values are typically obtained for each term of the P1 products as well as for each term of the other sets of products of the storage unit 82. Thus the summation of the terms of the P1 product of the summer 112 and the subsequent multiplication in the multiplier 122 of the sum by the factor on line 130 produces an estimate of the α 1 Legendre coefficient rather than an exact value of the Legendre coefficient. Similar comments apply to the operation of the summer 114 with the multiplier 124 to produce the estimate of the α 2 coefficient and also to the operation of the summer 116 with the multiplier 126 as well as the summer 118 with the multiplier of 128 to produce their corresponding coefficient estimates. It is noted that the line 130 is seen to branch out into each of the multipliers 122-128 to produce separate factors for each of the multipliers 122-128 wherein the value of n differs for each of the multipliers 122-128 while the value of L is the same for each of the multipliers 122-128.
The estimates of the Legendre coefficients from the multipliers 122-128 are combined in the calculator 120 to produce a number on line 131 representing ν c , the normalized frequency at the peak value of the spectrum. The signals representing ν c and f o on lines 131 and 107 are then summed by the summer 87 to produce a digital number on line 60 which represents a magnitude of the Doppler frequency f c as measured in a coordinate along an axis of one of the beams 24 of FIG. 1. The first of the four receivers 48 of FIG. 2 provides a digital signal on line 60 corresponding to the magnitude of the Doppler frequency for the beam 24 produced by the first of the transducers 22, while the other ones of the receivers 48 produce digital numbers corresponding to the magnitudes of the Doppler frequencies as seen along the beam axes of the corresponding ones of the transducers 22. It is noted that, while the exemplary showing of the preferred embodiment in FIG. 3 utilizes four Legendre coefficients, a still more precise representation of the Doppler frequency can be obtained by using further coefficients of the Legendre series and that the mathematical modeling of the Doppler spectrum by the use of orthogonal functions, particularly the Legendre polynomials, becomes more accurate with the utilization of an increased number of terms of the orthogonal function series. Two alternative formulations shown in the boxes 134 and 136 are utilized by the calculator 120 to exemplify a combination of the Legendre terms and to produce the component of the Doppler frequency on line 60. The formulations shown in the boxes 134 and 136 were derived approximately and depend on parameters such as the air bubbles, the rocks, and the mud referred to earlier in FIG. 1 since these characteristics of the medium through which the sonic radiation propagates affect the shape of the Doppler spectrum. A knob 138 of the calculator 120 permits manual selection of a formula such as that of the box 134 or the box 136 for producing the component of the Doppler frequency on line 60. The formula in box 134 has been found useful for reflection from a uniformly rough hard bottom of the ocean which results in a Gaussian distribution of the spectral lines. The formula in box 136 treats more complex situations such as a combination of the aforementioned hard bottom with organic matter. It is noted that the system 20 of FIGS. 1 and 2 is useful both in situations wherein sound is reflected from the bottom 27 of the ocean 28 as well as from air bubbles within the ocean 28 or other reflecting mechanism such as fish, within the ocean 28. Thus, in very deep water wherein echoes received from the bottom 27 are too weak to operate the sampler 70 of FIG. 3, the system 20 can still operate with reflections received from air bubbles and fish. It is also noted that while the teachings herein are directed to sonic radiation, they are also applicable to electromagnetic radiation propagating through the atmosphere, such as in the case of an airplane flying over the ocean with electromagnetic energy being reflected from the ocean back to the airplane.
Referring now to FIG. 4, there is seen a block diagram of the vector summer 50 and its interconnections to the receivers 48 via the lines 60 and the interconnections to the display 34 via line 140. Apart from a scale factor which is provided by the electronics of the display 34, the summer 50 combines the Doppler frequency components of the beams 24 of FIG. 1 to produce longitudinal and transverse components of the Doppler frequency on the line 140, the longitudinal and the transverse components being in a horizontal plane with the longitudinal component being along the longitudinal or roll axis of the ship 26 of FIG. 1.
The summer 50 is seen to comprise six summers 141-146. The summer 141 subtracts the signal of receiver #3 from the signal of receiver #1 to produce a forward component of the Doppler frequency, or ship speed which is proportioned thereto. Assuming the ship 26 of FIG. 1 to be traveling in the forward direction, the Doppler frequency received at transducer #1 is positive while that received by transducer #3 is negative. Accordingly, the aforementioned subtraction of the signal of the receiver #3 compensates for the negative value of the Doppler frequency in the combining of the signals of the receivers #1 and #3 by the summer 141. Similar comments apply to the combination of the signals of the receivers #2 and #4 by the summer 142. The resulting summations produced by the summers 141 and 142 are applied to the summer 143 wherein they are summed together to produce the longitudinal component of the Doppler frequency on line 148.
Assuming also that the ship 26 may have a transverse component to its velocity and, further assuming that the positive sense of the transverse component is to starboard, it is seen that the subtraction of the signal of receiver #2 from the signal of receiver #1 by the summer 144 produces a portion of the transverse component of the Doppler frequency. The subtraction of the signal of receiver #2 compensates for the negative Doppler frequency shift imparted to signals received by transducer #2 in response to a positive movement of the ship 26. Similar comments apply to the subtraction of the signal of receiver #4 from the signal of receiver #3 by the summer 145. The resulting summations of the summers 144 and 145 are summed together by the summer 146 to produce the transverse component of the Doppler frequency on line 150, or the transverse component of the ship's velocity which is proportional thereto. Digital-to-analog converters 152 and 154 convert the digital numbers representing respectively the longitudinal component and the transverse component-to-analog signals, the analog signals being seen to fan into the line 140 for coupling them to the display 34 of FIG. 2. The display 34, by way of example, utilizes the analog signals representing the longitudinal and the transverse components of the Doppler frequency for energizing the x and y components of a cathode ray tube (not shown) to develop a vector having the magnitude and direction of the maximum value of the Doppler frequency, this being proportional to the ship's velocity.
As noted hereinabove, the beams 24 of FIG. 1 are orientated at approximately 25° to the vertical axis of the ship 26. Thus, it is seen that a horizontal component of the Doppler frequency received along any one of the beams 24 has a magnitude equal to approximately one-half of the magnitude of the Doppler frequency received at the corresponding transducer 22. Thus the aforementioned scale factor would be approximately one-half and, accordingly, the factor one-half is accounted for in the calibration of the display 34.
Referring now to FIG. 5, there is seen a block diagram of the sampler 70, previously seen in FIG. 3. The 70 sampler comprises a mixer 156 coupled via line 91 to the gate 68 of FIG. 3, an oscillator 158, a phase detector 160, a 90° phase shifter 162, a phase-locked loop 164, two converters 166 and 168 of analog-to-digital signals, a gate 170, a counter 172, a complementing unit 174, a scaler 176, and a digital filter 180 which provides the nominal value of Doppler frequency on line 107 to the summer 87 of FIG. 3. The converters 166 and 168 provide inphase and quadrature digital numbers on lines which are seen to fan into line 106 for coupling these digital numbers to the storage unit 72 of FIG. 3. The gate 170 is driven by the signal on line 88 from the tracker 66 of FIG. 3 and functions in the same manner as does the gate 68 of FIG. 3. Terminal T2 provides timing signals from terminal T of FIG. 3, and is seen to have five lines fanning out into terminals T21-25 for providing timing signals to the sampler 70.
The phase-locked loop 164 is seen to comprise a phase detector 182, a low pass filter 184, a sample and hold circuit hereinafter referred to as sampler 186, a voltage controlled oscillator 188, and a mixer 190 which is coupled via terminal R to the oscillator 38 of FIG. 2.
By way of example, the echo signal coupled via line 58 of FIG. 3 and line 91 of FIG. 5 has a carrier frequency of 10 kHz. The oscillator 158 produces a sinusoid at a frequency of 5 kHz which is coupled to the mixer 156, the oscillations of the oscillator 158 being synchronized by a timing signal at terminal T21 to the oscillations of the oscillator 38. The mixer 156, which is understood to include an output filter which passes 15 kHz signals while rejecting signal frequencies of 10 kHz and 5 kHz, provides the echo signal, translated to a 15 kHz carrier, to the phase detector 182 of the loop 164 as well as to the phase detector 160. The oscillator 188 of the loop 164 produces a square wave signal on line 192 having a frequency of 5 kHz, the signal on line 192 being coupled to both the mixer 190 and the counter 172. The mixer 190 combines a 10 kHz sinusoidal signal from terminal R with the signal on line 192 to produce a signal on line 194 having a frequency of 15 kHz, the signal on line 194 being coupled to the phase detector 182, and via the phase shifter 162 to the phase detector 160.
With reference to FIGS. 5 and 6, the phase-locked loop 164 has a sufficiently large bandwidth to permit its acquiring the phase of the signal on line 196 of the mixer 156 during the duration of the waveform 90, previously seen adjacent the line 88 in FIG. 3, and also seen in the second graph of the timing diagram of FIG. 6. The acquisition time of the loop 164 is seen in the third graph of FIG. 6. The difference in phase between the signals on the lines 196 and 194 are detected by the phase detector 182, this difference being filtered by the filter 184 and applied via the sampler 186 to control the frequency of oscillation of the oscillator 188. The filtered difference signal coupled via the filter 184 to the sampler 186 is portrayed in the third graph of FIG. 6. The filtered difference signal has a substantially constant value subsequent to the acquisition of phase lock by the loop 164. In view of the fact that a sample of the transmitted signal is coupled into the loop 164 via terminal R, the oscillator 188 need respond only to variations in Doppler frequency to preserve phase lock of the loop 164, since any variations in the transmitted frequency appearing in the echo signal on line 91 are cancelled out by the mixer 190. The bandwidth of the filter 184 is sufficiently narrow relative to the bandwidths of the other components of the loop 164 such that the loop bandwidth, stability and acquisition time are determined by the bandpass characteristic of the filter 184 and the gain of an amplifier (not shown) contained therein. Thus, in accordance with the well-known practice in the design of phase-locked loops, the loop 164 acts as a tracking filter to track the phase and frequency of the echo signal on line 91.
With reference to the timing diagram of FIG. 6, it is seen that the gates 68 and 170 are operated for a relatively short interval of time relative to the interval of time between successive pulses of the transmitted signal portrayed in the first graph. Thus, the loop 164 receives a signal on line 196 for a relatively short interval of time with no input signal being received during a major portion of the time interval between successive echo signals. The loop 164 is made responsive to the signal on line 196 only during the time of reception of the echo signal by means of the sampler 186 and the gate 170. Terminal T23 provides timing signals at a rate more than double the bandwidth of the loop 164, for example at a rate of 50 kHz, these timing signals being passed by the gate 170 to strobe the sampler 186. Since the gate 170 is activated by the signal on line 88 as is the gate 68, the strobing of the sampler 186 occurs only at the time when the echo signal is anticipated. Accordingly, when the gate 170 is activated, the sampler 186 samples the signal from the filter 184, holds that sample and couples that sample to the oscillator 188. Upon the next strobing by the next timing signal at terminal T23, the sampler 186 repeats its sampling operation to again sample the signal from the filter 184, hold that sample and apply the sample to the oscillator 188. This sampling procedure is continued repetitively until the termination of the pulsed signal on line 88 at which time the last remaining sample of the sampler 186 is held at a constant value until the gate 170 is again activated at the time when the next echo signal is anticipated. The successive samplings of the sampler 186 is seen in the fourth graph of FIG. 6 which shows the retaining of the last sample during the interval of time subsequent to the termination of the operation of the gate 170. By virtue of the sampler 186 holding its last sample until the next echo, the frequency of the loop 164 is constrained to follow that of the Doppler frequency so that the acquisition time for acquiring the phase of the Doppler signal from subsequent echoes is greatly reduced. Accordingly, the loop 164 is able to function in the manner of a phase-locked loop which tracks a signal that is continuously present, even though the loop 164 must track a signal which is present for a small fraction of the time between successive echoes.
By virtue of the phase shifter 162, the signal on line 194 serves as an inphase reference for the phase detector 182 while serving as a quadrature reference for the phase detector 160. Thus, the output signals of the phase detectors 182 and 160 which are coupled to the converters 166 and 168, respectively, bear inphase and quadrature relationships. The output signals of the phase detectors 182 and 160 are in an analog format, the analog format being converted to digital numbers by the converters 166 and 168 in response to a strobing of the converters 166 and 168 by a timing signal at terminal T22. While the signal on line 196 is substantially that of a pulsed sinusoid, the detection of the signal on line 196 by phase detectors 182 and 160 results in noise-like signals which are produced by the phase detectors 182 and 160. These noise-like signals are characterized by the Doppler spectrum, referred to hereinabove, which is centered at the nominal Doppler frequency. As a result, the digital numbers coupled from the converters 166 and 168 via the line 106 to the storage unit 72 of FIG. 3 represent samples of the Doppler signal translated on the frequency scale by f o , the nominal Doppler frequency. With reference to the graph 198 of FIG. 3 which shows the spectra of the transmitted and received signals, the aforementioned translation of the Doppler spectrum by f o amounts to a centering of the Doppler spectrum about zero frequency. Since both the inphase and quadrature components of the Doppler signal are coupled via the line 106, the phase and amplitude data within the Doppler spectrum are retained during the translation of the Doppler spectrum to permit the signal processing, in the manner described above, by the components of the receiver 48 of FIG. 3.
The frequency of the signal on line 192 is measured by the counter 172 which counts cycles of the signal on line 192 during an interval of time during which it is enabled by a timing signal at terminal T24, this interval being shown in the bottom graph of FIG. 6. Assuming, by way of example, a maximum Doppler frequency shift of 30 Hz, and that an accuracy on the order of 1/3 Hz is desired, the counter 172 is enabled for an interval of time sufficient to count to the number 16,384, this being 2 raised to the power of 14, for zero Doppler frequency shift. In FIG. 6, this interval of time is shorter than the interval between transmitted signals in which case the period between transmitted signals, or between received echoes, is presumed to be on the order of five seconds or greater. For shorter periods of time, the enabling interval of the counter 172 would extend over a plurality of echoes. Each digit or bit of the count of the counter 172 is seen to be coupled via individual lines which fan into line 200 for coupling to the complementing unit 174. The complementing unit is energized by line 202 which couples the most significant bit of the count to the complementing unit 174 for strobing the complementing unit 174 to take the complement of the multibit digital number representing the count of the counter 172. Either the count or the complement thereof is coupled by the complementing unit 174 to the subtractor 176.
In the event that an echo signal received along one of the beams 24 of FIG. 1 contains a positive Doppler frequency shift, then the frequency of the signal on line 192 is in excess of 5 kHz with the result that the counter 172 counts more than 16,384 counts. The counter 172 counts modulo 16,384 and, accordingly, in the event that, for example, ten additional counts were accumulated during the counting interval, a count of ten would appear on line 200. On the other hand, in the event that a negative Doppler frequency shift were present, the frequency on line 192 would be less than 5 kHz, and the maximum count reached by the counter 172 would be, for example, a count of ten less than the maximum count of 16,384. By energizing the complementing unit 174, the number 10 appears on line 204. The most significant bit which appears on line 202, for energizing the complementing unit 174, also serves as a sign bit to the number appearing on line 204. The line 202 is seen to fan into the line 204 to give both the magnitude and sense of the Doppler signal on line 204.
The scaler 176 scales the magnitude of the digital number on line 204 to give the magnitude of the Doppler frequency. With reference to the foregoing example, it is noted that the enabling interval of the counter 172 has a duration of approximately three seconds. Accordingly, the number of counts received on line 204 is approximately three times the Doppler frequency. Thus, the scaler 176 multiplies the magnitude of the number on line 204 by a factor of approximately 1/3 to provide the correct value of Doppler frequency shift to the digital filter 180.
The filter 180 comprises an averaging circuit which, in response to timing signals at terminal T25 stores and sums together a number of values of Doppler frequency, for example 8, and divides this sum by that number, 8 in this example, to give an average value of the nominal Doppler frequency f o on line 107. The digital numbers appearing on line 107 are then summed together, as noted hereinabove, with the digital numbers on line 131 by the summer 87 of FIG. 3. The sign bit of line 202 is retained during this summation and is utilized in the subsequent summation in the vector summer 50 of FIG. 4. Thereby, the sense of the Doppler frequency for each of the beams 24 of FIG. 1 is retained during the vector summation.
It is understood that the above described embodiment of the invention is illustrative only and that modifications thereof may occur to those skilled in the art. Accordingly, it is desired that this invention is not to be limited to the embodiment disclosed herein, but is to be limited only as defined by the appended claims. | A system for Doppler frequency measurement, responsive to spectral modulation induced by a reverberant and nonlinear radiation transmissive region such as the ocean, and composed of a Fourier transformer for providing digitally the spectral lines for a set of samples of a Doppler signal, a circuit for obtaining the logarithm of the power spectrum, weighting of the logarithm by othogonal functions, and an arithmetic combination of components of the weighted logarithm. | 8 |
This is a continuation of application Ser. No. 658,238, filed Oct. 5, 1984, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to a well-treating or operating process for measuring patterns or profiles of temperatures with distances within intervals of subterranean earth formations which can be long, deep and hot. More particularly, the invention relates to installing and operating equipment for obtaining such information in an economically feasible manner, particularly while a well is being operated as a temperature observation well or is being heated or utilized in a manner affecting the temperature in and around the well.
Various temperature measuring processes have been described in patents. U.S. Pat. No. 2,676,489 described measuring both the temperature gradient and differential at locations along a vertical line in order to locate the tops of zones of setting cement. U.S. Pat. No. 3,026,940 discloses the need for heating wells for removing paraffin or asphalt or stimulating oil production and describes the importance of knowing and controlling the temperature around the heater. It uses a surface located heater arranged to heat portions of oil being heated by a sub-surface heater, with the control needed to obtain the desired temperature at the surface located heater being applied to the sub-surface heater.
Various temperature measuring systems involving distinctly different types of sensing and indicating means for use in wells have also been described in U.S. patents. For example, patents such as U.S. Pat. Nos. 2,099,687; 3,487,690; 3,540,279; 3,609,731; 3,595,082 and 3,633,423 describe acoustic thermometer means for measuring temperature by its effect on a travel time of acoustic impulses through solid materials such as steel. U.S. Pat. No. 4,430,974 describes a measuring system in which a plurality of long electrical resistance elements are grouted in place within a well and sequentially connected to a resistance measuring unit to measure temperature or fluid flow.
U.S. Pat. No. 3,090,233 describes a means for measuring temperatures within a small reaction zone, such as one used in a pilot plant. A chain drive mechanism pushes and pulls a measuring means such as a thermocouple into and out of a tube extending into the reaction zone while indications are provided of the temperature and position within the tube.
In some respects, the present invention amounts to a modification of the system described in U.S. Pat. No. 3,090,233. The prior system mechanically pushed and pulled a relatively stiff measuring assembly and suggested no way in which a temperature sensing means, such as a thermocouple, could be moved for significant distances up and down within a well. But, Applicants have discovered with a certain combination of elements measurements can be made within subterranean earth formation intervals while are relatively very deep, very long, and very hot. This requires a combination of a long measuring means conduit, an electrically responsive temperature sensing means which telemeters electrical responses along a metal sheathed telemetering cable which is heat stable, a flexible weighting means connected below the sensing means and a means for spooling the telemetering cable and requires that those elements be arranged to have physical and chemical properties which are properly interrelated. In addition, Applicants found that in contrast to previously described methods for measuring sub-surface temperatures within wells, the presently described interrelated combination of elements is particularly beneficial in being capable of providing substantially equilibrated temperature measurements from all points along a long interval of subterranean earth formations without involving any more man hours than are needed for the quick scan of a computer printout. In contrast, the prior methods for obtaining such temperature logs have required continual attendance, and delayed well operation, for days or weeks.
SUMMARY OF THE INVENTION
The present invention relates to a process for treating and/or operating a well while measuring temperatures in or around a well within subterranean intervals which can be hundreds of feet long, thousands of feet deep, and hot enough to require pyrometric measurements. A long, substantially straight measuring means conduit is extended within the well from a surface location to the interval to be measured. A flexible weighting member, an electrically responsive temperature sensing means, a spoolable heat stable cable for telemetering the sensing means signals and a means for spooling in and paying out the telemetering cable are arranged and interconnected so that the gravitational force on the weighting means is capable of substantially straightening the bends in the telemetering cable, and pulling the temperature sensing means and telemetering cable downward within the measuring means conduit without significantly cold working the cable during the bending and straightening of it. The spooling means is operated so that the temperature sensing means is pulled downward within the measuring interval by gravity and is pulled upward within that interval by spooling the telemetering cable onto a drum. The rate of the movement is controlled so that electrical temperature responses are telemetering from the temperature sensing unit while that unit is, to the extent desired, in substantial temperature equilibrium with the temperatures encountered within the measuring interval. Indications are made of temperature corresponding to the telemetered electrical responses and temperature measuring locations corresponding to the position of the temperature sensing means, which position corresponds to the extent of the unspooling of the telemetering cable from the spooling means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of the system of the present invention installed in a mini-well or measuring means conduit extending alongside a string of casing cemented within a well.
FIG. 2 is an enlarged view of a section of that mini-well.
FIG. 3 is a block diagram of circuits for controlling the operations of the spooling means shown in FIG. 1.
FIG. 4 is a schematic illustration of an alternative arrangement in which a measuring means conduit of the present invention is used as both a mini-well and a guide column for a heater cable.
DESCRIPTION OF THE INVENTION
FIG. 1 shows a borehole 1 in which a string of casing 2 is installed and grouted by cement 3. Such a way may, for example, be a temperature observation well, a well in which a heater is being operated to mobilize a viscous oil or to coke a portion of the coil in a reservoir to form a sand consolidated zone or an electrode to which electrical current is to be flowed through the reservoir, or the like.
A slender measuring means conduit 4 is extended along the casing 2 into and through a "logging" interval to be measured. The conduit 4 is preferably spoolable and is strapped to a pipe string such as casing 2 and surrounded by a body of cement, such as cement 3, which surrounds the casing to ensure a substantially uniform heat transport to or from the earth formation and avoid the flow of fluid into or out of the casing. The measuring means conduit is preferably tightly closed by a bottom located seal 5 which can be, for example, a cap, a plug, a weld, a body of cement, or the like.
A temperature sensing assembly comprising a flexible weighting member or "flexible sinker bar" 6, a thermocouple hot junction 7 and a thermocouple signal telemetering cable 8 (more clearly depicted in FIG. 2) are disposed within the measuring means conduit 4. The flexible weighting member or flexible sinker bar 6 comprises a series of sinker bar beads (i.e., short weights) 6A slidably connected around a flexible line 6B, and kept separated from each other by bead stops 6C, which are fixedly attached to line 6B.
The telemetering cable 8 for transmitting the electrical responses from the thermocouple hot junction preferably comprises the thermocouple wires, or conductive wires having similar thermal electrical characteristics, insulated by nonconductive solid material which is suitably heat stable for use at the temperature being measured. As known to those skilled in the art, although thermocouples were first developed for use in pyrometry they are now competitive with resistance thermometers and various expansion and pressure types of thermometers, for measuring lower ranges of temperatures, and with radiation methods for measuring very high temperatures.
The position of a temperature sensing means 7 within the interval to be measured corresponds to the extent the cable 8 is unspooled from the cable spooling means 9. The cable spooling means control 10 controls the rate at which the temperature sensing means is moved within the interval being measured.
In general, the controls are arranged to adjust the speed and torque of the spooling drive motor. The travel rates are preferably variable from about 3 to 2,000 inches per minute. The unspooling rate should, of course, be kept slow enough to avoid spiraling or kinking of the telemetry cable. A particularly suitable logging rate is about 6 inches per minute which provides a traverse of 300 feet of subterranean earth formation interval in about 10 hours. The electrical response temperatures are transmitted (for example, by a mercury slip-ring assembly) to measurement indicating units.
The measuring means conduit is preferably a spoolable continuous stainless steel tube, preferably one which has an inner diameter of about 5/16ths to 9/16ths of an inch and is, or is substantially equivalent to, a grade 316 stainless steel. The measuring means conduit is preferably attached, for example, by strapping, along the exterior of a tubing or casing string. The points of the attachment should be located at the largest diameters of such a pipe string, e.g., at the pipe collars, to keep the measuring means conduit as straight as possible, particularly with respect to avoiding a spiraling around a casing or tubing to which the measuring means conduit is attached.
The sinker bar beads such as beads 6A used in a conduit of the preferred size preferably have an outer diameter of about 3/16ths to 7/16ths inch and a length of about 1 to 6 inches. In such an arrangement, the flexible sinker line 6B is preferably a flexible line such as a 1/16ths inch aircraft wire and the bead stops 6C are preferably small pieces of small tubing such as 1/8th-inch tubing crimped tightly onto the sinker line in positions that keep the beads separated by about 1/2-inch.
In general, the components of the combination comprising a flexible weighting member like flexible sinker 6, an electrically responsive temperature sensing means like thermocouple junction 7, a metal sheathed telemetering cable like cable 8 and a means for spooling the telemetering cable like spooling means 9, should have chemical and physical properties and interconnections arranged so that gravity acting on the sinker bar is capable of pulling the sensing means downward through the measuring interval while substantially straightening the bends imparted by the drum of the spooling means. Applicants have found, by means of well tests, that such an arrangement and interconnection of properties is exemplified by a measuring means conduit comprising a 3/8ths-inch inside diameter by 1/2-inch outside diameter 316 stainless steel tube, a flexible sinker bar comprising 80 beads which are 2 inches long by 1/4th-inch diameter (providing a total weight of about 2 pounds and a length of about 17 feet), where the cable for telemetering electrical temperature responses is a steel sheathed 1/16ths-inch diameter cable which is spooled on a spooling means having a drum diameter of about 19 inches.
With respect to such a combination of items the cold working of the telemetering cable (due to being bent around the spooling means drum) is only about 0.3 percent. Where the measuring means conduit deviation from a generally vertical line (with respect to spiraling or substantially reversing turns, such as "dog legs") is practically nil, the temperature sensing means not only moves smoothly downward in response to gravity (with no evidence of interference due to friction) but no significant load due to friction is apparent while raising the system by spooling it onto the spooling means drum. Tests have indicated that where the same combination of items is used in a measuring means conduit having spiraling deviations from the vertical, although the downward motion may be satisfactory, the pulling up of the system may place a load on the telemetering cable amounting to more than its tensile strength, due to friction.
FIG. 3 shows the main circuitry components for controlling a cable spooling means such as means 9 of FIG. 1. As will be apparent to those skilled in the art, substantially all of the indicated components can be the same as, or like, components which are commercially available. A data logger is arranged to receive depth and temperature signals and transmit coded control commands to a logging rate and direction control circuit, which in turn activates a motor control circuit to provide direction and rate signals to the spooling means motor. A depth encoder derives thermocouple position indicating signals from the extent at which the telemetering cable 8 is unspooled. The binary coded decimal depth signals are converted to hexadecimal depth signals which are supplied to the data logger, along with the temperature signals from the thermocouple.
The data logger is arranged to provide data and receive commands, via a telephone modem, to and from on site and/or remote locations. The available keyboard commands include logging control direction, logging speed and data regarding depth and temperature. Thus, the system can automatically accumulate temperature measurements at a continuous or intermittent rate which is slow enough to ensure substantial equilibrium between the sensing unit and the surrounding temperature without any interruption of the well operation or any significant amount of time of the operating personnel. Where a subterranean interval is to be heated at a relatively high temperature, the present process can be particularly valuable. The measuring conduit means conduit is extended throughout the interval near the heater to be used. While operating the heater to bring it up to the selected heating temperature the logging speed for the temperature sensing assembly is set to provide relatively rapid traverses of the interval in order to detect any developing hot spots anywhere along the intervals before any significant damage has occurred. When the heater temperature reaches or approaches the selected heating temperature the logging speed can be reduced to a rate conducive to maintaining a thermal-equilibrium between the sensing means and the borehole temperature.
The use of the telephone modem is also particularly advantageous in mountainous terrain where radio communications or personnel monitoring is difficult or impractical. The present system can be used for a central control of a large number of heat injectors in a field scale operation.
FIG. 4 shows an alternative arrangement of a placement and use of a measuring means conduit, in accordance with the present invention. The system shown in FIG. 4 is a formation-tailored method and means for uniformly heating a long subterranean interval at high temperature. It is described in a commonly assigned application, Ser. No. 597,764 filed Apr. 6, 1984. The disclosures of that application are incorporated herein by reference.
As shown in FIG. 4, the measuring means conduit is arranged to serve as a heater cable guide column. It is pulled from an air motor driven guide column spool through the interior of a stationary drum and into a well casing by the weight of a guide column sinker bar. A pair of heater cables each comprising a conductive metal core surrounded by mineral insulation encased in a stainless steel sheath are connected to a pair of metal sheathed, mineral insulated, power supply cables and lengths of those cables which are sufficient to allow the heater cables to extend through the casing to the zone to be heated are wound around a rotating cable guide mounted on the stationary drum through which the tubular guide column is extended. The heater cables are spliced together with an end piece splice which is connected to the guide column. As the guide conduit is lowered into the casing, turns of the heater cables followed by turns of the power supply cables are removed and fed into the casing in the form of spiraling coils in which the turns have a suitable wave length. When the downward travel of the guide column is terminated, the coils of the cables press outward against the inner wall of the casing and much, if not all, of their weight tends to be supported by the friction between them and the wall.
In such an arrangement, in accordance with the present process, after a guide column comprising the measuring means conduit of the present invention has been run-in, it is preferably hung from a wellhead hanger, which can be like those conventionally used for hanging strings of continuous tubing. If a pressure greater than atmosphere is to be generated within the casing containing the measuring means conduit, the temperature sensing assembly of the present invention can be fed in through a lubricator, which can be like those conventionally used. The lubricator should, of course, be arranged so that the friction imparted by it does not prevent the gravity-actuated downward travel of the temperature sensing means. | In treating a well, automatically controlled measurements of temperature with depth within a subterranean interval which can be longer than hundreds of feet, deeper than thousands of feet and hotter than 600° C., are made by extending a slender measuring means conduit through the well and the zone to be measured and arranging an electrically responsive temperature sensing means and a means for spooling a metal sheathed telemetering cable for the electrical temperature responses so that the sensing means is lowered through the measuring conduit by gravity and raised within the conduit by spooling and temperatures and/or temperature with depths are measured while the sensing means temperature is substantially in equilibrium with the temperatures in the interval being measured. | 4 |
FIELD OF THE INVENTION
This invention relates to maintenance and repair of nuclear reactors. In particular, the invention relates to the repair of the fuel core shroud of a boiling water reactor.
BACKGROUND OF THE INVENTION
A conventional boiling water reactor is shown in FIG. 1. Feedwater is admitted into a reactor pressure vessel (RPV) 10 via a feedwater inlet 12 and a feedwater sparger 14, which is a ring-shaped pipe having suitable apertures for circumferentially distributing the feedwater inside the RPV. A core spray inlet 11 supplies water to a core spray sparger 15 via core spray line 13. The feedwater from feedwater sparger 14 flows downwardly through the downcomer annulus 16, which is an annular region between RPV 10 and core shroud 18. Core shroud 18 is a stainless steel cylinder which surrounds the core 20, which is made up of a plurality of fuel bundle assemblies 22 (only two 2×2 arrays of which are shown in FIG. 1). Each array of fuel bundle assemblies is supported at the top by a top guide 19 and at the bottom by a core plate 21. The core top guide provides lateral support for the top of the fuel assemblies and maintains the correct fuel channel spacing to permit control rod insertion.
The water flows through downcomer annulus 16 to the core lower plenum 24. The water subsequently enters the fuel assemblies 22, wherein a boiling boundary layer is established. A mixture of water and steam enters core upper plenum 26 under shroud head 28. Core upper plenum 26 provides standoff between the steam-water mixture exiting core 20 and entering vertical standpipes 30, which are disposed atop shroud head 28 and in fluid communication with core upper plenum 26.
The steam-water mixture flows through standpipes 30 and enters steam separators 32, which are of the axial-flow centrifugal type. The separated liquid water then mixes with feedwater in the mixing plenum 33, which mixture then returns to the core via the downcomer annulus. The steam passes through steam dryers 34 and enters steam dome 36. The steam is withdrawn from the RPV via steam outlet 38.
The BWR also includes a coolant recirculation system which provides the forced convection flow through the core necessary to attain the required power density. A portion of the water is sucked from the lower end of the downcomer annulus 16 via recirculation water outlet 43 and forced by a centrifugal recirculation pump (not shown) into jet pump assemblies 42 (only one of which is shown) via recirculation water inlets 45. The BWR has two recirculation pumps, each of which provides the driving flow for a plurality of jet pump assemblies. The pressurized driving water is supplied to each jet pump nozzle 44 via an inlet riser 47, an elbow 48 and an inlet mixer 46 in flow sequence. A typical BWR has 16 to 24 inlet mixers. The jet pump assemblies are circumferentially distributed around the core shroud 18.
Stress corrosion cracking (SCC) is a known phenomenon occurring in reactor components, such as structural members, piping, fasteners, and welds, exposed to high-temperature water. The reactor components are subject to a variety of stresses associated with, e.g., differences in thermal expansion, the operating pressure needed for the containment of the reactor cooling water, and other sources such as residual stress from welding, cold working and other inhomogeneous metal treatments. In addition, water chemistry, welding, heat treatment, and radiation can increase the susceptibility of metal in a component to SCC.
Stress corrosion cracking has been found in the shroud girth seam welds or heat affected zones of the core shroud 18. This diminishes the structural integrity of the shroud, which vertically and horizontally supports core top guide 19 and shroud head 28. Thus, there is a need for a method and an apparatus for repairing a shroud which has cracks in or near the shroud girth seam welds.
SUMMARY OF THE INVENTION
The present invention is a method and an apparatus for repairing a shroud in which one or more shroud girth seam welds have experienced SCC. The method involves the placement of a plurality of brackets around the outer circumference of the shroud at a plurality of azimuthal positions, held by shear pins positioned between jet pump assemblies. In the event of multiple cracked shroud girth seam welds, respective pluralities of brackets are installed at respective elevations. The brackets are intended to structurally replace the shroud girth seam welds which are cracked.
The shroud repair brackets in accordance with the invention are designed to support the top guide, the fuel bundle assemblies and the shroud head. The brackets are further designed to withstand the thermal and radiological conditions which the shroud is subjected to. The shroud repair brackets are fastened to the shroud above and below the cracked shroud girth seam weld in a manner which will prevent relative movement across the cracked shroud girth seam welds during all normal and upset conditions. Further, the shroud repair brackets of the present invention are designed and installed such that removal of jet pump inlet mixers and RPV beltline inspection can be performed without removal of the repair brackets.
Each bracket has a plurality of circular holes for receiving a corresponding one of a plurality of tapered pin assemblies. A corresponding plurality of circular holes are machined in the shroud wall at positions which will align with the holes in the bracket. Then the bracket is correctly positioned outside the shroud with the circular holes of the bracket and shroud in alignment. A corresponding tapered pin assembly is blindly installed in each set of aligned holes and then manipulated remotely to fasten the bracket to the shroud.
In accordance with the preferred embodiment of the invention, each tapered pin assembly consists of three types of parts: a threaded tapered pin, a slotted sleeve with a tapered bore, and a threaded nut. The pin has threads and a socket on one end and a precise conical taper on the other end. When fully installed, the tapered pin is encased by the sleeve. The sleeve has a longitudinal slot which allows the sleeve to be flexed radially outward into a configuration having an expanded diameter. In the unflexed state, the slotted sleeve has a precise internal taper which matches the external conical taper of the pin; an external surface having a radius of curvature which is smaller than the radius of curva-ture of the holes in the shroud and in the repair bracket; and a raised annular flange to act as an axial position stop. The annular flange is sized to just pass through the holes in the bracket and shroud when the sleeve is unflexed. The nut is tightened to pull the pin enough to expand the sleeve by an amount sufficient that the annular flange will not pass through the holes. Then the pin is tensioned to produce the desired preload, during which the sleeve expands further. Thereafter the nut is lock welded to the pin.
All steps in the installation of the shroud repair bracket assemblies in accordance with the invention are performed remotely and outside the shroud. In particular, the tapered pin assemblies in accordance with the invention can be entirely installed from outside of the shroud. Prior to insertion, the unflexed sleeve is slided onto the tapered pin and then the nut is threaded onto the pin for a number of turns sufficient to hold the unflexed sleeve in place. This yields a minimum flange diameter which is less than the diameter of the holes in the bracket and shroud wall, allowing the sleeve to pass through the holes. The assembly is then pushed through the aligned holes in the bracket and shroud wall. Once the raised flange of the sleeve clears the inner edge of the hole in the shroud wall, the nut is tightened to pull the tapered pin back until the assembly is seated, i.e., the annular flange on the sleeve latches behind the shroud wall. During this operation, the sleeve is held in place initially by a thrust plate on the tool, reacting between the nut and the sleeve, and then after some expansion, by the raised flange bearing against the inner circumferential surface of the shroud wall. Higher axial load is then applied with a tensioner. This applies a contact pressure between the pins, sleeve, bracket and shroud. The magnitude of this contact pressure can be controlled by varying the tension applied to the pin, by varying the taper angle and by varying the surface conditions.
This shroud repair design is advantageous because it allows fast installation using the minimum number of fasteners. All holes in the shroud are circular cylindrical so that machining the shroud holes is simplified. Because the repair brackets can be installed entirely from the outside of the shroud, it is unnecessary to remove the top guide or the fuel bundle assemblies. The number of brackets needed to accomplish the repair is reduced due to the high load capacity of the shear pins and the splice plates. Also the brackets in accordance with the preferred embodiment of the invention occupy little space in the reactor, which minimizes the impact on other activities inside the reactor. The bracket size and number of pins per bracket can be selected based on the space available and the magnitude of the seismic loads anticipated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic showing a partially cutaway perspective view of a conventional BWR.
FIG. 2 is a sectional view of a portion of the core shroud of the BWR shown in FIG. 1 with installed shroud repair bracket assemblies in accordance with a preferred embodiment of the invention.
FIG. 3 is an azimuthal view of a portion of the core shroud showing brackets in accordance with the invention installed at three different elevations.
FIG. 4 is a sectional view of an installed shroud repair bracket assembly in accordance with the preferred embodiment of the invention.
FIG. 5 is an isometric view of a tapered pin assembly having a slotted sleeve in accordance with the preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The core shroud 18 (see FIG. 2) of a conventional BWR comprises a shroud head flange 18a for supporting the shroud head 28; a circular cylindrical upper shell section 18b welded to shroud head flange 18a; an annular top guide support ring 18c welded to upper shell section 18b; circular cylindrical top and bottom mid-core shell sections 18d and 18e joined at core mid-plane weld 50, with top section 18d welded to top guide support ring 18c and bottom section 18e welded to an annular core plate support ring 18f; and a lower shell section 18g welded to the core plate support ring 18f. The top and bottom sections 18d and 18e of the mid-core shell section are of equal diameter. The diameter of upper shell section 18b is greater than the diameter of mid-core shell sections 18d and 18e, which is in turn greater than the diameter of lower shell section 18g. The entire shroud is supported by shroud support 51, which is welded to the bottom of lower shell section 18f, and by annular shroud support plate 52, which is welded at its inner diameter to shroud support 51 and at its outer diameter to RPV 10. All of the aforementioned welds extend around the entire circumference of the shroud and constitute the shroud girth seam welds.
Stress corrosion cracking has been found in the shroud girth seam welds or heat affected zones thereof. In accordance with the preferred embodiment of the present invention, a plurality of shroud repair bracket assemblies are arranged around the shroud circumference at the elevation of the stress corrosion cracking. The purpose of these bracket assemblies is to structurally replace the shroud girth seam welds which are potentially undermined by cracks. Brackets may be installed only at welds found to have cracking.
Each shroud repair bracket is fastened to the shroud above and below the crack elevation in a manner which will prevent relative movement across the shroud girth seam welds during all normal and upset conditions. As seen in FIGS. 2 and 3, in accordance with the repair technique of the present invention, a plurality of bracket assemblies 60a, 60b and 60c are installed at different elevations: one for reinforcing cracks in the welds joining shroud head flange 18a to upper shell section 18b; one for reinforcing cracks in the top guide support ring 18c; and one for reinforcing cracks in the core mid-plane weld 50.
Bracket assembly 60a has a bracket 62a for splicing shroud head flange 18a to upper shell section 18b when cracking occurs in the girth welds joining those sections. Preferably, bracket 62a is a curved plate having a radius of curvature approximately equal to the outer radius of upper shell section 18b. As seen in FIG. 3, bracket 62a is provided with a notch for each shroud head bolt lug 54 to be circumvented. Bracket 62a is fastened to upper shell section 18b by two tapered pins 66 and to shroud head flange 18a by two tapered pins 66', pins 66' being longer than pins 66.
Bracket assembly 60b has a bracket 62b for splicing upper shell section 18b to top section 18d of the mid-core shell section when the top guide support ring is cracked. Preferably, bracket 62b is a welded assembly of curved plates, the upper curved plate having a radius of curvature approximately equal to the outer radius of upper shell section 18b and the lower curved plate having a radius of curvature approximately equal to the outer radius of top section 18d of the mid-core shell section. Bracket 62b is fastened to upper shell section 18b and to top section 18d of the mid-core shell section by respective pairs of tapered pins 66.
Finally, bracket assembly 60c has a bracket 62c for splicing top section 18d to bottom section 18e of the mid-core shell section when the core mid-plane girth weld is cracked. Preferably, bracket 62c is a curved plate having a radius of curvature approximately equal to the outer radius of the mid-core shell section. Bracket 62c is fastened to top section 18d and to bottom section 18e of the mid-core shell section by respective trios of tapered pins 66.
In accordance with the preferred embodiment of the invention, each bracket is fastened to the shroud using tapered pin assemblies 64 which couple with aligned holes in the bracket and shroud. As seen in FIG. 4, the holes 72 in the bracket and holes 74 in the shroud wall are circular cylindrical and of equal diameter. Holes 74 are remotely machined in the shroud wall by a conventional electric discharge or other suitable machining technique.
FIG. 4 shows bracket 62c fastened to the top and bottom sections 18d and 18e of the mid-core shell section by tapered pin assemblies 64 in accordance with the preferred embodiment of the invention. Each tapered pin assembly comprises a threaded tapered pin 66, a slotted sleeve 68 and a threaded nut 70. The tapered pin has threaded portion 66b and a socket 66c on one end and an external conical, i.e., tapered, surface 66a on the other end. Each tapered pin 66 is held inside the holes 72, 74 by slotted sleeve 68 and threaded nut 70.
When fully installed, the tapered portion of pin 66 is encased by slotted sleeve 68. The sleeve, shown in detail in FIG. 5, has a longitudinal slot 69 which allows the sleeve to be flexed radially outward into a configuration having an expanded diameter. The flexed sleeve 68 has an internal conical surface 68a which matches the external conical surface 66a of pin 66; an external surface 68b having a radius of curvature which matches the radius of curvature of hole 72 in the bracket and hole 74 in the shroud; and a raised flange 68c to act as an axial position stop.
The tapered pin assemblies in accordance with the invention can be entirely inserted from one side of the shroud. Prior to insertion, the unflexed sleeve 68 is slided onto the tapered pin 66 and then the nut 70 is threaded onto the pin for a number of turns sufficient to hold the unflexed sleeve 68 in place. At this stage, the diameter of annular flange 68c is less than the diameter of the holes 72, 74 in the bracket and shroud wall, allowing the sleeve 68 to pass through the holes. The assembly is then pushed through the aligned holes in the bracket and shroud wall until the nut 70 abuts the bracket 62c. Once the raised flange 68c of the sleeve 68 clears the inner edge of hole 74 in the shroud wall 18d, nut 70 is tightened to pull tapered pin 66 back until the assembly is seated, i.e., the annular flange 68c on the sleeve latches behind the shroud wall. During this operation, the sleeve is held in place initially by a thrust plate on the tool (not shown), reacting between the nut and the sleeve, and then after some expansion, by the raised flange bearing against the inner circumferential surface of the shroud wall. Higher axial load is then applied with a tensioner. This applies a contact pressure between the pins, sleeve, bracket and shroud.
The nut 70 has internal threads which engage the external threads on the threaded portion 66b of pin 66. During installation of the tapered pin assembly 64, a tool is inserted into socket 66c of pin 66 to prevent pin rotation. A tool with a hexagonal socket is coupled to the hexagonal head 70a of nut 70 and used to remotely tighten nut 70. Nut 70 further comprises a built-in washer 70b which has a circumferential flange of radius greater than the radius of hole 72. Thus, when nut 70 is tightened, the flange of washer 70b bears against the bracket 62c on the perimeter of hole 72, not against the end of the sleeve.
The outwardly flexed sleeve 68 has an outer circular cylindrical surface 68b of radius equal to the radius of circular holes 72 and 74. The tapered portion 66a of pin 66 applies increasing pressure on sleeve 68 during pin tensioning. When pin 66 is tensioned to the desired amount, nut 70 is tack-welded to the threaded portion 66b of pin 66 to lock the assembly in place. The tensioned pin assembly exerts a radially outwardly directed contact pressure on the cylindrical surfaces of the aligned circular holes 72, 74 respectively formed in the bracket and shroud, to hold the assembly securely in place.
A stud tensioning device can be used to apply large contact pressures, which result in a large friction force which will react loads axial to the pin assembly. Alternatively, where blind installation is not required, the sleeve flange and the head of the tapered pin could be large so that the required preload is small.
The contact pressure against the core shroud causes tensile stresses in the shroud, which could be of concern in highly irradiated steel. This concern can be mitigated by applying a noble metal (e.g., platinum or palladium) coating to the pin assembly or by alloying appropriate noble metals with the pin assembly materials. The noble metal will catalyze the recombination of water, thereby reducing the susceptibility of the shroud material to stress corrosion cracking.
In accordance with an alternative embodiment, the slotted sleeve can be replaced by a plurality of tapered sleeve segments. The angle of the tapered sleeve segments is dependent on their number. For example, if there are two sleeve segments, then each one covers slightly less than 180°. If there are three sleeve segments, then each one covers slightly less than 120°. Each sleeve segment has a precise internal taper which matches the external conical taper of the pin; an external surface having a radius of curvature which matches the radius of curvature of the holes in the shroud and in the repair bracket; and a raised flange to act as an axial position stop. The use of a plurality of sleeve segments, unlike the slotted sleeve, requires employment of a special tool to hold the sleeve segments in place during installation of the tapered pin assemblies.
A bracket suitable for repairing the shroud at a location where no change in diameter occurs, such as the shroud portion shown in FIG. 4, could be a piece of plate which is curved to conform to the shroud. If the repair is needed at a location where a change in shroud diameter occurs, e.g., at the top guide support ring 18c or at the core plate support ring 18f, the bracket could be a casting, forging or welded plate assembly (such as assembly 62b in FIG. 2). The thickness of the bracket assembly is selected based on the available space and the structural requirements. The preferred thickness is in the range of 1 to 3 inches. The number and location of the tapered pins is selected based on the maximum structural loads that must be carried by the repair brackets. The primary structural loads are due to postulated seismic events. The preferred configuration is four pins per bracket. However, six, eight, twelve or more pins could be used. The size of the bracket in the circumferential direction is determined based on the space available. The preferred width is approximately 3 to 5 feet. The height of the brackets is approximately 1 to 5 feet. Each pin assembly has an outside diameter of between 2 and 5 inches.
The preferred embodiment of the shroud repair bracket in accordance with the present invention has been disclosed for the purpose of illustration. Variations and modifications of the disclosed structure which do not depart from the concept of this invention will be readily apparent to mechanical engineers skilled in the art of tooling. For example, the number of sleeve segments may be two or more, so long as the sum of the angles is less than 360° by an amount which allows the sleeve segments to pass through the holes in the bracket and shroud wall when the sleeve segments are in contact with the backed-off nut. Further, the brackets may be provided with raised bearing pads which extend around the periphery of holes 72. These pads allow local machining to precisely match the contact surface of the bracket to the curved external surface of the shroud wall. Also, the socket on the end of the tapered pin can be replaced by a slot. All such variations and modifications are intended to be encompassed by the claims set forth hereinafter. | A method and an apparatus for repairing a shroud in which one or more shroud girth seam welds have experienced SCC. The method involves the placement of a plurality of brackets around the outer circumference of the shroud at a plurality of azimuthal positions. Each bracket has circular holes for receiving respective tapered pin assemblies. Corresponding circular holes are machined in the shroud wall at positions which will align with the holes in the bracket. Each tapered pin assembly is inserted and then manipulated remotely from outside the shroud. Each tapered pin assembly consists of three types of parts: a threaded tapered pin, a slotted sleeve with a tapered bore, and a threaded nut. When fully installed, the tapered pin is encased by the sleeve. As the tapered pin is tensioned, the sleeve exerts a radially outwardly directed contact pressure on the cylindrical surface of the aligned circular holes respectively formed in the bracket and shroud. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a novel catalytic combination of reactants, in particular molecular weight controllers, suitable for use with caprolactam (continuous or discontinuous) polymerization processes.
2. Prior Art
The polymer yielded by the polymerization of caprolactam (Nylon 6) in the presence of suitable additives contains about 10% of a hydroextractable material composed of caprolactam monomers and cyclic oligomers containing 2 to 7 monomeric units. Such materials must be removed from caprolactam because they considerably deteriorate the polymer characteristics, making it unusuable as a prime material for conversion into a yarn or as a man-made polymer for molding. Such materials tend to form a deposit on the extrusion dies and to surface from the extruded articles in the course of subsequent processing steps, depositing, for instance, on the spinning line rollers or creating problems of various natures during the molding step.
In particular caprolactam monomers, where the polymer is converted into a yarn or polymer porcessing temperatures in the 250°-265° C. range, would evaporate from the molten polymeric material and solidify over the cool areas of the system, thus producing degradation products which may discontinue the spinning process. Cyclic oligomers may readily migrate to the surface of the yarn thus produced and create a malfunction of both the rotary drive and winding members, and of the baths for subsequent dyeing, which would be highly contaminated by such products.
The extractable material, 80 to 85% of which is composed of caprolactam, is conventionally removed either by scrubbing the formed polymer with water, which process is power-consuming, or by effecting a so-called demonomerization during the polymerization itself by vacuum application. It is, however, necessary that, during the polymerization process, the polymer be so structured as to have a diminshed tendency to form caprolactam monomer and cyclic oligomers, and that the formation rate of caprolactam monomer and cyclic oligomers from the molted polymer be lower than the rate of removal of such extractable materials.
It is known that the propensity or non-propensity of the polymer to form caprolactam monomers in particular, and the reaction kinetics in general, are a function of the concentration of the terminal groups and the degree of polymerization, and that this is in turn dependent, among others, on temperature.
Past investigation work carried out by the Applicant has shown that in order to limit the formation of caprolactam, especially while spinning, the content of terminal amino-groups should be as small as possible. It has been found, for example, that in the instance of a polymer containing about 60-65 equiv/10 6 g of terminal carboxylic groups, the tendency of the polymer to reform caprolactam monomers, with the polymer maintained in the molten state, has an increasing pattern up to about 40 equiv/10 6 g of terminal amino-groups. Besides that concentration, the amount of reformed monomer, which is indicative of the monomer reformation rate from the molten polyamide, is maintained at a substantially constant high value.
Accordingly, in order to make the formation rate of extractable material as low as possible, which is an all-important condition for a process not providing for a water scrubbing step, it becomes necessary to synthesize a polyamide having the lowest possible content of terminal amino-groups.
On the other hand, however, the need for significant polymerization kinetics requires the provision of some terminal groups (both amino and carboxylic) because these groups enable molecular weight to be increased. Further, where the polycaprolactam is converted into a yarn, then the terminal amino-groups become necessary to impart the fiber with a good dye-taking capability.
The carboxylic groups are required to trigger the polymerization reaction, however, they also tend, albeit to a lesser degree, to promote the monomer formation where the polymer is born in the molten state.
Thus, the need arises therefrom for synthesizing a polyamide which can meet at one time the following requirements:
(a) significant polymerization kinetics, compatibly with an industrial process, and hence, with determined values of terminal, amino, and carboxylic groups;
(b) good dye-taking ability of an article obtained from the fiber resulting from that polyamide, as determined, inter alia, by the presence of amino-groups; and
(c) the rate of formation of extractable material (both monomer and cyclic dimer), with the polymer maintained in the molten state, to be the lowest possible, whereby the amount of amino groups should be as small as possible.
Since the amino and carboxylic groups of polyamide 6 vary according to the amounts and types of substances with an acidic or basic character (molecular weight controller) respectively introduced from the outset of the polymerization, by changing the relative compositions of the molecular weight controllers, one can change the content of the terminal groups.
Known in the art are many molecular weight controllers, both having an acidic nature and a basic nature, used both singly or combined together.
Known in particular is the use of mono- and di-amines having at least 6 carbon atoms and of mono- and dicarboxylic acids (U.S. Pat. No. 3,578,640), which are added individually to the reaction mass as chain terminators or molecular weight controllers in the continuous production of caprolactam having a relatively low extractable material content. Also known is to use primary or secondary amines (UK Pat. No. 1,532,603), and cyclohexylamine acetate (U.S. Pat. No. 3,477,094).
However, the molecular weight controllers used in prior polymerization processes fail to achieve at one time all of the three objectives mentioned above.
It has been now unexpectedly found that it is possible to achieve simultaneously such objects, i.e. it is possible to obtain a polyamide having significant polymerization kinetics, a high dye-taking ability, and a low content of monomer and cyclic oligomers in the molten state polymer, if a particular combination of molecular weight controllers is used, which combination affords control capabilities in a desired manner over the final product of a caprolactam polymerization process, in terms of the overall terminal amino-group content.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of this invention to provide a combination of molecular weight controllers which is especially useful with caprolactam polymerization processes, and which can yield a stabilized polyamide having an overall extractable material content not exceeding 0.7% by weight, and good dye-taking characteristics.
A further object of the invention is to provide a stabilized polyamide having a molecular weight in the 13,000 to 20,000 range, preferably in the 16,000 to 18,000 range, an extractable material content not exceeding 0.7% by weight, and in particular a caprolactam monomer content not exceeding 0.25%, and a cyclic dimer content not exceeding 0.15% and having a concentration of terminal amino-groups within 22 to 42 equiv/10 6 g with respect to the polymer total weight, the polyamide being obtained by means of a caprolactam polymerization process which utilizes the combination of molecular weight controllers according to this invention.
These and other objects, such as will be more readily apparent hereinafter, are achieved by a combination of molecular weight controllers useful with caprolactam polymerization processes and characterized in that it comprises the three following components:
(a) a monofunctional primary amine having a boiling point equal to or higher than 180° C. at atmospheric pressure, and a basic dissociation constant equal to or higher than 1.7×10 -5 ;
(b) a monofunctional organic acid having an acid dissociation constant higher than 1.5×10 -5 ; and
(c) an aminoacid containing at least 10 carbon atoms and having its amino groups salified by a monofunctional acid having an acid dissociation constant higher than 1.0×10 -2 .
As the component (a), particularly preferred amines are nonylamine, decylamine, and benzylamine; as the component (b), acetic acid and some homologs such as propionic, butyric, amylic, acid, etc. are preferably used.
The component (c) is an aminoacid, preferably aminododecanoic acid, having its amino groups salified by an acid which may be either organic or inorganic and should have an acid dissociation constant higher than 1.0×10 -2 .
Suitable salifying acids are, for example, p-toluenesulphonic acid, naphtalenesulphonic acid, hydrochloric acid, and metaphosphoric acid.
The overall amount of the three components, in the combination of molecular weight controllers added in the polymerization medium, should not exceed 85 equiv/10 6 g with respect to the polymer weight total, because larger amounts would lower the molecular weight of the finished polymer and damage the yarn mechanical properties, nor should it be less than 50 equiv/10 6 g with respect to the total polymer amount.
More specifically, the amount (as expressed in equiv/10 6 g) of basic groups introduced with the molecular weight control system--i.e. component (a) plus component (c)--will preferably range from about 20 to 46 equiv/10 6 g, and the amount of component (b) will be in the 23 to 50 equiv/10 6 g range.
Within the indicated range for the total of two components (a)+(c), the specific component ratios will vary according to the desired final characteristics for the polymer. In practice, the third component (c) will be added in an amount corresponding to about 1/3 to about 1/2 the amount of component (a).
With the combination of molecular weight controllers according to this invention, including the three components specified above in the indicated amounts, and used as described hereinafter with a caprolactam polymerization process, a polyamide is obtained which has the following characteristics:
a terminal amino-group content in the 22 to 42 equiv/10 6 g range, preferably from 26 to 35 equiv/10 6 g;
a terminal carboxylic group content in the 5 to 20 equiv/10 6 g range, preferably from 10 to 15 equiv/10 6 g
a numeric molecular weight in the 13,000 to 20,000 range;
a content of caprolactam monomer content of 0.25% by weight in the molten polymer;
a dimer content in the molten polymer of 0.15% by weight; and
an overall content of extractables in the molten polymer of 0.7% by weight.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The components of the molecular weight controller combination of this invention may be added separately from one another, or jointly, in the polymerization medium which is comprised of water and caprolactame, or alternatively, may be admixed individually with the caprolactam.
The polymerization of caprolactam in the continuous process using the combination of molecular weight controllers according to this invention may be carried out under the following conditions.
The amount of water added initially to the monomer may be in the 0.5% to 2% by weight range.
The polymerization reaction is effected in two steps, both at a temperature within 230° C. to 260° C., preferably within 230° C. to 240° C. During the first step (of hydrolysis and polyaddition) the pressure is the autogenous pressure, whereas the second step (of polycondensation) is conducted under a very high vacuum, preferably at a residual pressure not exceeding 5 mm Hg.
Under such conditions, caprolactam, and in part also the lower cyclic oligomers (dimer and trimer) are evaporated. Further, the evaporated hydroextractable portion does not reform, or is reformed at a slower rate than the amount which is being removed during polycondensation.
Thus, the polyamide produced by this process is extractable material-poor and requires no scrubbing (or extracting) with water prior to its conversion into a yarn.
The catalytic combination of the three molecular weight controllers according to this invention may be employed, however, not only with the continuous process described hereinabove, wherein demonomerization is carried out concurrently with polymerization under high vacuum, but also with conventional polymerization processes wherein the polycondensation reaction (step II of polymerization) is conducted at a residual pressure in the 100 to 700 mm Hg range. In that case, the polymer should be extracted (scrubbed) with water prior to its conversion into a yarn because the content in extractable material of the formed polymer is higher than in the former process embodiment, but with the advantage of having a lower rate of reformation of monomer and oligomers in the molten state than a polyamide yielded by a conventional process utilizing prior MW controllers.
The duration time of the polymerization process may vary from 5 to 40 hours, depending on the overall amount of the components, of the molecular weight controllers, and on the process used to polymerize the caprolactam.
In the following examples intended to illustrate the invention without limiting its scope, the determination of the content of caprolactam and the individual cyclic oligomers (from dimer to heptamer) is effected by liquid chromatography (Hewlett Packard, Liquid-Chromatograph 1010B). To prepare the sample, the polymer, as ground and sieved down to 1 mm particle size, is extracted for 16 hours with water to boiling. The filtrate is dry evaporated, then vacuum dried at 60° C., and for the analysis, dissolved in a 40/60 mixture of trifluoroethanol/water.
The stability of the resulting polymer is checked by analyzing the content in monomers and oligomers of the polymer yielded at the end of the polymerization process and of the polymer melted at 260° C. under a slow nitrogen stream and maintained in these conditions for one hour, and then re-solidified.
The smaller the percent difference (Δ) between the two contents thus obtained, i.e. between the amounts of monomer and dimer formed in the molten polymer, the stabler is the polymer analyzed.
In the Examples which follow, all parts and percentages are by weight, unless otherwise specified.
EXAMPLE 1 (conventional method except that the combination of this invention is used)
113 parts caprolactam, 1.05 parts water, 0.26 parts acetic acid, 0.556 parts benzylamine, and 0.34 parts aminododecanoic N-chlorohydrate acid are heated to 230° C. in a sealed vessel. Autogenous pressure is 1.5 atmospheres, and the conditions are maintained for 6 hours.
After bringing the vessel down to atmospheric pressure while raising the temperature to 250° C., the reaction mass is maintained for 30 minutes in a stream of pure nitrogen (oxygen content below 5 ppm). Thereafter, the vessel internal pressure is gradually lowered to 250 mm Hg residual pressure, and the conditions are maintained for 7 hours.
After cooling, the resulting polyamide is ground and sieved. The particles, of a smaller size than 1 mm diameter, are extracted with water to boiling for 16 hours.
After drying, the extracted (scrubbed) polyamide has the following properties:
______________________________________molecular weight = 16,700content in amino-groups = 31 equiv/10.sup.6 gcontent in monomer = 0.13%content in cyclic dimer = 0.12%content in other oligomers = 0.23%______________________________________
A quota of extracted and dried polyamide is placed in a vessel heated to 260° C. under a slow nitrogen stream and maintained in that condition for one hour. After cooling, the polyamide is again analyzed by liquid chromatography as mentioned hereinabove, and the following values are obtained:
______________________________________content in monomer = 0.19%content in cyclic dimer = 0.12%content in other oligomers = 0.18%______________________________________
Thus, the amounts (Δ) of caprolactam and oligomers formed in the molten polymer are, respectively:
______________________________________Δ caprolactam = 0.06%Δ cyclic dimer = --Δ other oligomers = --______________________________________
Such low values for Δ mean that the polyamide obtained with the process described in Example 1, owing to the use of the molecular weight controller combination of this invention, is perfectly stabilized against the formation of extractable material.
EXAMPLE 2 (reference example; conventional method)
The same procedure as in Example 1 is used, excepting that as the molecular weight controller acetic acid alone is used in the amount of 0.27 parts per 113 parts caprolactam and 1 part water, and that residual pressure within the vessel is 400 mm Hg.
The following results are obtained, in the extracted (scrubbed) polyamide:
______________________________________molecular weight = 17,800content in amino-groups = 28 equiv/10.sup.6 gcontent in monomer = 0.15%content in cyclic dimer = 0.13%content in other oligomers = 0.25%______________________________________
in the polyamide maintained in the molten state:
______________________________________content in monomer = 1.75%content in cyclic dimer = 0.53%content in other oligomers = 0.16%______________________________________
amount (Δ) of extractable material formed:
______________________________________Δ caprolactam monomer = 1.6%Δ cyclic dimer = 0.4%Δ other oligomers = --______________________________________
The polyamide obtained in this example is not stabilized and has a strong tendency to reform monomers and dimers as the polyamide is maintained in the molten state.
EXAMPLE 3 (continuous process under high vacuum, using the inventive combination)
113 parts caprolactam, 1.2 parts water, 0.61 parts benzylamine, 0.26 parts acetic acid, and 0.38 parts aminododecanoic N-p toluenesulphonate acid are introduced into a sealed vessel and the mixture is heated at 230° C. for 6 hours.
The vessel pressure is lowered from 15 atmospheres to atmospheric pressure, and then further lowered down to 1-2 mm Hg. The time required to reach high vacuum is 10 minutes, and such conditions are maintained for 4 hours.
For the unextracted but ground and sieved polymer, the chemical properties and oligomer compositions are determined.
A quota of the resulting polymer is subjected to melting conditions as described hereinabove, and the composition of the polymer containing compositions of the formed oligomers (Δ) and those contained in the polymer are again determined.
The results are shown in the Table.
EXAMPLE 4 (high vacuum process; example conforming with this invention)
Example 3 is repeated, except that the composition of the polymerization mixture is replaced with the following composition:
113 parts caprolactam
1.2 parts water
0.26 parts acetic acid
0.81 parts nonylamine
0.38 parts aminododecanoic N-p toluenesulphonate acid.
The results are shown in the Table.
EXAMPLE 5 (high vacuum process; reference example)
Example 3 is gone through again, except that the combination of molecular weight controllers according to this invention are replaced with the acetic acid along. The polymerization mixture has therefore the following composition:
113 parts caprolactam
1.05 parts water
0.58 parts acetic acid
The results are shown in the Table.
EXAMPLE 6 (high vacuum process; reference example)
Example 4 is gone through again, except that the combination of molecular weight controllers according to the invention are replaced with a binary mixture of acetic acid-nonylamine, thus doing without the third component of this invention.
The polymerization mass has the following composition:
113 parts caprolactam
1.05 parts water
0.26 parts acetic acid
0.74 part nonylamine
The results are shown in the Table.
TABLE__________________________________________________________________________ ANALYSIS OF THE FINISHED POLYMEREx. METHOD MW CONTROLLERS MW --NH.sub.2 CL % Di % R %__________________________________________________________________________1 POLYMERIZATION + Acetic acid; 16700 31** 0,13 0,12 0,23 SCRUBBING Benzylamine; Aminododecanoic N--chlorohydrate acid.2* POLYMERIZATION + Acetic Acid 18700 28 0,15 0,13 0,25 SCRUBBING3 UNDER HIGH Acetic acid; 18270 27** 0,21 0,12 0,37 VACUUM, Benzylamine; NO SCRUBBING Aminododecanoic N--p Toluenesulphonate ac4 UNDER HIGH Acetic acid; 18460 26** 0,19 0,13 0,38 VACUUM, Nonylamine; NO SCRUBBING Aminododecanoic N--p Toluenesulphonate ac.5* UNDER HIGH Acetic Acid 24750 0,5 0,30 0,32 0,47 VACUUM, NO SCRUBBING6* UNDER HIGH Acetic Acid 16570 26 0,31 0,21 0,43 VACUUM, Nonylamine. NO SCRUBBING__________________________________________________________________________ ANALYSIS OF THE POLY- MER AS MELTED AND RE-SOLIDIFIED ΔEx. METHOD MW CONTROLLERS CL % Di % R % CL % Di % R__________________________________________________________________________1 POLYMERIZATION + Acetic acid; 0,19 0,12 0,18 + 0,06 -- -- SCRUBBING Benzylamine; Aminododecanoic N--chlorohydrate acid.2* POLYMERIZATION + Acetic Acid 1,75 0,53 0,16 +1,60 +0,40 -- SCRUBBING3 UNDER HIGH Acetic acid; 0,20 0,14 0,33 -- +0,02 -- VACUUM, Benzylamine; NO SCRUBBING Aminododecanoic N--p Toluenesulphonate ac4 UNDER HIGH Acetic acid; 0,20 0,14 0,36 +0,01 +0,01 -- VACUUM, Nonylamine; NO SCRUBBING Aminododecanoic N--p Toluenesulphonate ac.5* UNDER HIGH Acetic Acid 0,31 0,43 0,46 -- +0,11 +0,01 VACUUM, NO SCRUBBING6* UNDER HIGH Acetic Acid 0,37 0,28 0,45 +0,06 +0,07 +0,02 VACUUM, Nonylamine. NO SCRUBBING__________________________________________________________________________ *Reference Examples. **The amounts of Aminogroups shown also include those salified, nontitratable. CL % = Monomer Percentage; DI % = Cyclic Dimer Percentage; R % = Percentage of other olygomers present, from trimer to heptomer; --NH.sub. = Amount of terminal aminogroups expressed as Equiv/10.sup.6 g of the polymer weight total; MW = Molecular Weight.
It may be noted that it is only with the combination of the three molecular weight controllers of this invention that it becomes possible to obtain a stabilized polyamide against the formation of monomers and oligomers in the polymer yielded following residence in the molten state. In fact, the values for Δ in Examples 1, 3 and 4 according to the invention are considerably lower than in the reference Examples, e.g. Example 2, where CL reaches 1.6%; even though for the scrubbed polymer the contents in oligomers and monomers are low.
In reference Example 6, using components (a) and (b) but not component (c), the values for Δ show an improvement over reference Examples 2 and 5, wherein acetic acid alone is used, but the content of the monomers and oligomers of the resulting polyamide after residence in the molten state are high.
The amount of terminal amino-groups, including the salified ones, obtained in the Examples according to the invention is sufficiently large to impart the fiber thus obtained from the polyamide with a good dye-taking ability, and since a part of such amino-groups are salified, it is also adapted, as shown in the Examples, to provide stabilized polyamides or polyamides having a low monomer and cyclic oligomer content. | The invention is concerned with a combination of molecular weight controllers to be used in the production of a stabilized polyamide having a low content of monomers and oligomers and a high dye-taking capability by polymerization of caprolactam. The combination comprises: (a) a primary monofunctional amine having its boiling point at 180° C. above, and a basic dissociation constant K b ≧1.7×10 -5 ; (b) a monofunctional organic acid having a K a >1.5×10 -5 ; and (c) an aminoacid containing at least ten carbon atoms having the --NH 2 group salified by a monofunctional organic or inorganic acid which has K a >1.0×10 -2 . With this combination, a polyamide is obtained which, following residence in the molten state, has a monomer content of 0.25% or less and a dimer content of 0.15% or less. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a serial communication device and a method of carrying out serial communication both used for confounding a memory in duplex, and more particularly to such a serial communication device and a method of carrying out serial communication both presenting the same reliability as reliability presented by a parallel bus.
[0003] 2. Description of the Related Art
[0004] [0004]FIG. 1 is a block diagram of a conventional system for making communication in duplex confounding.
[0005] The system is comprised of a first parallel bus controller 10 , a second parallel bus controller 12 , a first buffer circuit 11 a associated with the first parallel bus controller 10 and electrically connected between the first and second parallel bus controllers 10 and 12 , a second buffer circuit 11 b associated with the second parallel bus controller 12 and electrically connected between the first buffer circuit 11 a and the second parallel bus controller 12 , a 32-bit address bus 13 , a 32-bit data bus 14 , and a 5-bit parity 15 .
[0006] The 32-bit address bus 13 , the 32-bit data bus 14 and the 5-bit parity 15 are all electrically connected between the first and second parallel bus controllers 10 and 12 through the first and second buffer circuits 11 a and 11 b.
[0007] Communication in duplex confounding between the first and second parallel bus controllers 10 and 12 is made through the 32-bit address bus 13 and the 32-bit data bus 14 .
[0008] Errors in parallel buses, that is, in the 32 -bit address bus 13 and the 32-bit data bus 14 are detected through the 5-bit parity 15 .
[0009] The above-mentioned conventional system illustrated in FIG. 1 is accompanied with a problem that since the system has to include a lot of signal line for the parallel buses, the system unavoidably has a plurality of buffer circuits 11 a and 11 b , resulting in much defectiveness in fabrication of the system and high cost for fabricating the system.
[0010] It would be possible to accomplish reduction in both cost and defectiveness in fabrication of the system, if the parallel buses are replaced with serial buses. However, the use of serial bus causes another problem that bit errors occur during communication, and hence, it is impossible to ensure the same reliability as reliability obtained when parallel buses are used.
[0011] Japanese Patent No. 2971006 (Japanese Unexamined Patent Publication No. 8-265393) has suggested a method of carrying out serial communication in a serial communication controller including at least one first buffer for receiving data and at least one second buffer for transmitting data. In the method, the first buffer is used for receiving data and the second buffer is used for transmitting data when data is received and transmitted in full-duplex communication. The first and second buffers are used only for receiving data when data is received in half-duplex communication. The first and second buffers are used only for transmitting data when data is transmitted in half-duplex communication.
[0012] However, the above-mentioned problems remain unsolved even in the method suggested in the above-mentioned Publication.
SUMMARY OF THE INVENTION
[0013] In view of the above-mentioned problems in the conventional system, it is an object of the present invention to provide a serial communication device and a method of carrying out serial communication both of which are capable of reducing the number of parts to thereby accomplish reduction in cost and defectiveness in fabrication, and providing the same reliability as reliability obtained when parallel buses are used, even though serial buses are used in place of parallel buses.
[0014] In one aspect of the present invention, there is provided a serial communication device bridging between a parallel bus and a serial bus, including (a) a check bit producer which applies an error correcting code to parallel data transmitted through the parallel bus, and (b) a parallel-serial converter which converts the parallel data output from the check bit producer, into serial data.
[0015] The serial communication may further include a parallel bus interface circuit which multiplexes the parallel data transmitted through the parallel bus, in predetermined bits, and outputs the thus multiplexed parallel data to the check bit producer, in which case, the parallel-serial converter converts the parallel data into serial data every the predetermined bits, and the check bit producer applies the error correcting code to every the predetermined bits of the parallel data.
[0016] There is further provided a serial communication device bridging between a parallel bus and a serial bus, including (a) a serial-parallel converter which converts serial data transmitted through the serial bus, into parallel data, and (b) an error detector which checks an error correcting code applied to the serial data, and detects an error in the error correcting code.
[0017] It is preferable that the error detector has a function of correcting the error when the error is detected by the error detector.
[0018] It is preferable that the error detector corrects the error when the error is a 1-bit error, and abandons an access when the error is a 2-bit error.
[0019] There is still further provided a serial communication device bridging between a parallel bus and a serial bus, includes (a) a check bit producer which applies an error correcting code to parallel data transmitted through the parallel bus, (b) a parallel-serial converter which converts the parallel data output from the check bit producer, into serial data, (c) a serial-parallel converter which converts serial data transmitted through the serial bus, into parallel data, and (d) an error detector which checks an error correcting code applied to the serial data, and detects an error in the error correcting code.
[0020] The serial communication device may further include a parallel bus interface circuit which (a) multiplexes the parallel data transmitted through the parallel bus, in predetermined bits, and outputs the thus multiplexed parallel data to the check bit producer, and (b) receives parallel data from the error detector, and outputs the received parallel data to the parallel bus, in which case, the parallel-serial converter converts the parallel data into serial data every the predetermined bits, and the check bit producer applies the error correcting code to every the predetermined bits of the parallel data.
[0021] In another aspect of the present invention, there is provided a method of carrying out serial communication between a parallel bus and a serial bus, including the steps of (a) applying an error correcting code to parallel data transmitted through the parallel bus, and (b) converting the parallel data into serial data.
[0022] The method may further include the step of (c) multiplexing the parallel data transmitted through the parallel bus, in predetermined bits, the step (c) being to be carried out prior to the step (a), in which case, the parallel data is converted into serial data every the predetermined bits in the step (b), and the error correcting code is applied to every the predetermined bits of the parallel data in the step (a).
[0023] There is further provided a method of carrying out serial communication between a parallel bus and a serial bus, including the steps of (a) converting serial data into parallel data, (b) checking an error correcting code applied to the serial data, and (c) detecting an error in the error correcting code.
[0024] The method may further include the step of (d) correcting the error detected in the step (c).
[0025] The method may further include the steps of (d) correcting the error when the error is a 1-bit error, and (e) abandoning an access when the error is a 2-bit error.
[0026] There is still further provided a method of carrying out serial communication between a parallel bus and a serial bus, including the steps of (a) applying an error correcting code to parallel data transmitted through the parallel bus, (b) converting the parallel data into serial data, (c) converting serial data transmitted through the serial bus, into parallel data, (d) checks an error correcting code applied to the serial data, and (e) detecting an error in the error correcting code.
[0027] The advantages obtained by the aforementioned present invention will be described hereinbelow.
[0028] In accordance with the present invention, the number of parts for constituting the communication system can be reduced to thereby accomplish reduction in cost and defectiveness in fabrication of the communication system, and the same reliability as reliability obtained when parallel buses are used can be provided, even though serial buses are used in place of parallel buses.
[0029] The above and other objects and advantageous features of the present invention will be made apparent from the following description made with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] [0030]FIG. 1 is a block diagram of a conventional system for making communication in duplex confounding.
[0031] [0031]FIG. 2 is a block diagram of the serial communication device in accordance with a preferred embodiment of the present invention.
[0032] [0032]FIG. 3 is a time chart showing an operation of the serial communication device illustrated in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] [0033]FIG. 2 is a block diagram of the serial communication device in accordance with a preferred embodiment of the present invention.
[0034] The serial communication device is comprised of a bus bridge circuit 8 electrically connected to a parallel bus 1 including a 32-bit address bus and a 32-bit data bus, a parallel-serial converting circuit 4 electrically connected between the bus bridge circuit 8 and a serial bus 5 , and a serial-parallel converting circuit 6 electrically connected between the bus bridge circuit 8 and the serial bus 5 .
[0035] The bus bridge circuit 8 is comprised of a parallel bus interface circuit 2 electrically connected to the parallel bus 1 , a parallel-serial interface circuit 3 electrically connected between the parallel bus interface circuit 2 and the parallel-serial converting circuit 4 , a serial-parallel interface circuit 7 electrically connected between the parallel bus interface circuit 2 and the serial-parallel converting circuit 6 , a first 8-bit data-multiplexing bus 9 a electrically connecting the parallel bus interface circuit 2 and the parallel-serial interface circuit 3 to each other, and a second 8-bit data-multiplexing bus 9 b electrically connecting the parallel bus interface circuit 2 and the serial-parallel interface circuit 7 to each other.
[0036] The parallel and serial buses 1 and 5 may have any structure.
[0037] The parallel bus interface circuit 2 act as an interface to the parallel bus 1 . When data is transmitted to the serial bus 5 from the parallel bus 1 , the parallel bus interface circuit 2 multiplexes 32-bit address, data and command transmitted through the parallel bus 1 , into 8-bit (1 byte) addresses, data and commands, and outputs the thus multiplexed addresses, data and commands to the parallel-serial interface circuit 3 through the first 8-bit data-multiplexing bus 9 a . When data is transmitted to the parallel bus 1 from the serial bus 5 , the parallel bus interface circuit 2 transmits data multiplexed into 1-byte data, to the parallel bus 1 as 32-bit address, data and command.
[0038] The parallel-serial interface circuit 3 acts as an interface for transmitting serial data, and produces a bit for checking an error correcting code in serial communication (hereinafter, such a bit is referred to as “ECC check bit”). The parallel-serial interface circuit 3 receives address, data and command byte by byte from the parallel bus interface circuit 2 , produces a ECC check bit on receipt of 1-byte of address, data and command, applies the thus produced ECC check bit to each 1-byte of address, data and command, and outputs each 1-byte of address, data and command with the associated ECC check bit, to the parallel-serial converting circuit 4 .
[0039] The parallel-serial converting circuit 4 receives the parallel data byte by byte from the parallel-serial interface circuit 3 , converts the received parallel data to serial data, and outputs the thus converted serial data to the serial bus 5 .
[0040] The serial-parallel converting circuit 6 receives serial data through the serial bus 5 , converts the received serial data to parallel data byte by byte, and outputs the thus converted parallel data to the serial-parallel interface circuit 7 .
[0041] The serial-parallel interface circuit 7 detects a ECC check bit, corrects errors in error correcting codes, and acts as an interface for transmitting parallel data. Specifically, the serial-parallel interface circuit 7 checks ECC check bits in address, data and command to thereby detect errors in error correcting codes, and corrects the detected errors. Then, the serial-parallel interface circuit 7 converts 1-byte data transmitted from the serial-parallel converting circuit 6 , into 32-bit address, data and command, and multiplexes the 32-bit address, data and command into 8-bit (1 byte) addresses, data and commands, and outputs the thus multiplexed addresses, data and commands to the parallel bus interface circuit 2 through the second 8-bit data-multiplexing bus 9 b.
[0042] The serial-parallel interface circuit 7 checks the ECC check bits in address, data and command to thereby detect errors in the error correcting codes. If the serial-parallel interface circuit 7 detects a 1-bit error in the error correcting codes, the serial-parallel interface circuit 7 corrects the detected 1-bit error, whereas if the serial-parallel interface circuit 7 detects a 2-bit error in the error correcting code, the serial-parallel interface circuit 7 abandons an access associated the detected error.
[0043] [0043]FIG. 3 is a time chart showing a relation among addresses, data, commands and ECC check bits.
[0044] Hereinbelow is explained an operation of the serial communication device in accordance with the embodiment.
[0045] When data is transmitted to the serial bus 5 from the parallel bus 1 , the parallel bus interface circuit 2 multiplexes 32-bit address, data and command transmitted through the parallel bus 1 , into 8-bit (1 byte) addresses, data and commands, and outputs the thus multiplexed addresses, data and commands to the parallel-serial interface circuit 3 through the first 8-bit data-multiplexing bus 9 a.
[0046] The parallel-serial interface circuit 3 receives address, data and command byte by byte from the parallel bus interface circuit 2 , produces a ECC check bit on receipt of 1-byte of address, data and command, applies the thus produced ECC check bit to each 1-byte of address, data and command, and outputs each 1-byte of address, data and command with the associated ECC check bit, to the parallel-serial converting circuit 4 .
[0047] The parallel-serial converting circuit 4 receives the parallel data byte by byte from the parallel-serial interface circuit 3 , converts the received parallel data to serial data, and outputs the thus converted serial data to the serial bus 5 .
[0048] When data is transmitted to the parallel bus 1 from the serial bus 5 , address, data and command are transmitted to the serial-parallel converting circuit 6 through the serial bus 5 , and are converted into parallel data in 1-byte in the serial-parallel converting circuit 6 . The thus converted 1-byte parallel data are transmitted to the serial-parallel interface circuit 7 .
[0049] The serial-parallel interface circuit 7 converts the 1 -byte serial data transmitted from the serial-parallel converting circuit 6 , into 32-bit address, data and command, and multiplexes the 32-bit address, data and command into 8-bit (1 byte) addresses, data and commands, and outputs the thus multiplexed addresses, data and commands to the parallel bus interface circuit 2 through the second 8-bit data-multiplexing bus 9 b.
[0050] In addition, the serial-parallel interface circuit 7 checks the ECC check bits in address, data and command to thereby detect errors in the error correcting codes. If the serial-parallel interface circuit 7 detects a 1-bit error in the error correcting codes, the serial-parallel interface circuit 7 corrects the detected 1-bit error. If the serial-parallel interface circuit 7 detects a 2-bit error in the error correcting code, the serial-parallel interface circuit 7 abandons an access associated the detected error.
[0051] The 32-bit address, data and command are transmitted to the parallel bus interface circuit 2 from the serial-parallel interface circuit 7 , and then, transferred to the parallel bus 1 through the parallel bus interface circuit 2.
[0052] The parallel-serial interface circuit 3 produces the ECC check bits for address, data and command, and applies the ECC check bits to each 1-byte of address, data and command at timings illustrated in FIG. 3 in accordance with clock pulses.
[0053] Similarly, the serial-parallel interface circuit 7 checks the ECC check bits in address, data and command at timings illustrated in FIG. 3 in accordance with clock pulses.
[0054] While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.
[0055] The entire disclosure of Japanese Patent Application No. 2000-310113 filed on Oct. 11, 2000 including specification, claims, drawings and summary is incorporated herein by reference in its entirety. | A serial communication device bridging between a parallel bus and a serial bus, includes (a) a check bit producer which applies an error correcting code to parallel data transmitted through the parallel bus, (b) a parallel-serial converter which converts the parallel data output from the check bit producer, into serial data, (c) a serial-parallel converter which converts serial data transmitted through the serial bus, into parallel data, and (d) an error detector which checks an error correcting code applied to the serial data, and detects an error in the error correcting code. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims priority of U.S. Provisional Application Serial No. 60/042,878, filed Mar. 31, 1997, which is incorporated herein by reference for all purposes.
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the xerographic reproduction by anyone of the patent document or the patent disclosure in exactly the form it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF INVENTION
The present invention is directed to a method and apparatus for automatically recognizing and responding to intent in message text, particularly as used in a large-scale automatic message response system to examine input text and respond appropriately with output text relevant to the writer's intent.
BACKGROUND OF THE INVENTION
Electronic textual interchange is pivotal to businesses, academic institutions and private correspondence, and those recipients of electronic messages are being inundated with messages because of the increased popularity of electronic messaging and the migration to that medium from other messaging media, such as telephone calls, telegrams, physical (postal) mail, newspapers and magazines. This increase is, in part, due to the ease of access, the low cost of electronic exchange and because electronic messaging can be sent asynchronously and received quickly. While this medium allows for large amounts of information exchange, providing quick, relevant, and consistent responses to messages becomes increasingly difficult as the number of messages increases.
To alleviate these problems, some automated response systems have been proposed, with only limited success. In general, an automated response system processes an input message, attempts to “understand” what the writer is saying in the message, formulates an appropriate response and routes that response to the sender. Since many of the input messages are free-form text, a natural language processor and reasoning system is often used to “understand” what the input message is conveying, i.e., the intent of the sender. The term “understand” means the identification of information which corresponds to analogous situations previously identified by humans.
A typical message understanding system identifies words and other patterns in text, combining algorithmic and empirical methods to draw comparisons to known situations. Once the message is understood, a text generation system might be used to generate the response message text so that the entire communication response process is automated. The message understanding system might also include a classifier which understands the content of a message and routes or categorizes the message based on its content.
A number of approaches have been developed for automating text understanding and response. One approach to text understanding is to codify rules of natural language grammar. This approach is problematic because the rules of grammar are complicated, as well as incomplete, so systems based on them are difficult to produce and maintain. Another approach is to use statistical analysis of words within a text corpus, as is used in neural networks. Statistical analysis systems have the advantage that they are less difficult to maintain, but have the disadvantage that they are of limited usefulness where large amounts of relevant training data are not available.
Another approach to the problem of text understanding is to constrain and simplify the input message text. One way to do this is to have the writer of the input text use forms with limited choices and constrained syntax. Computer languages, with rigid and constrained syntax, are examples of how a user can communicate precisely with computers. While this approach greatly reduces the complexity of the process of automatic interpretation, it also requires prolonged, specialized user training.
Whether the messages are constrained or free-form, a message response system must first understand the input message text before it can process and respond to the message. One way to simplify the understanding and response process is to require manual intervention. The manual intervention approach has a number of drawbacks, since the process takes time and labor, requires training for reviewers and might result in inconsistency in responses from different reviewers. A manual review process might have the reviewer read a message and input a set of keywords, a classification, and/or a response. One approach to automating the manual process is to extract keywords from the input message and use them to compose a template response text. The drawback to this approach is that the keywords are chosen indiscriminately and are possibly irrelevant to the central intent of the input message text.
A problem with all the foregoing systems, with the exception of some applications of neural networks, is that system maintenance requires many of the same specialized skills required for original application development. Neural network systems can avoid that requirement, but they are limited to environments having a considerable amount of training data, a requirement which increases commensurately with the desired precision of classification. These systems classify without respect to meaning, i.e., irrelevant words are ineffectively separated from those central to intentionality.
Therefore, what is needed is a set of tools in a message text understanding and response system which reduces the requirement for specialized skills to produce and maintain domain specific applications.
SUMMARY OF THE INVENTION
An improved message text understanding and response system is provided by virtue of the present invention. In one embodiment of an understanding and response system, the system isolates the writer's critical words which relate to prototypical statements stored in the system. These in turn are mapped to models which represent understanding of the writer's possible intents. The writer's intents are then mapped to prototypical response actions as defined by the system operators. Thus the system models typical message writer requests and answers by selecting among typical responses.
To accomplish this, a tokenizing identifier accepts input message text and analyzes the text against a lexicon specific to the system operator's domain, in order to generate a structured data representation of input message text. The structured data and message text is fed to an intent identifier, which uses the structured text and a knowledge base to infer the intent of the writer of the input message. Intent determination can be supplemented by verifying and augmenting input message data against databases outside the system. The identified intents, and possibly the structured data and the message text itself, are passed to a response formulator, which assembles a set of actions according to a set of business rules to formulate a response. The assembled potential actions are evaluated and executed. Examples of potential actions include responding to the writer, giving recommendations for the next step in processing, possibly outside the system, routing the message to a third party for automatic or manual response, or invoking an external system.
The response message text, as well as the input message text, can be transported between the system and the writer of the message using conventional message transport techniques. The input message text can be electronic mail and may include text and other computer formats such as documents, graphic representations, formatted fields, and computer control characters. If the input message contains special formats of structured data, those are flagged for special processing which uses the additional information provided by the structure. The response actions can include: responding to the writer, creating a message summary for later review by system operators, forwarding the message for manual review, output the message to printers and facsimile machines, adding items to workflow systems, etc.
A further understanding of the nature and advantages of the inventions herein may be realized by reference to the remaining portions of the specification and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer system over which messages are sent to a server for automatic handling according to the present invention.
FIG. 2 is a more detailed block diagram of elements of the message text understanding and response system shown in FIG. 1 .
FIG. 3 is a more detailed block diagram of the message processing module shown in FIG. 2 .
FIG. 4 is a block diagram showing the natural language extraction module of FIG. 3 in greater detail.
FIGS. 5 ( a )-( b ) illustrate the process of using the apparatus shown in FIGS. 1-3 to automatically respond to a message.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the present invention provides a framework for recognizing, storing, and matching domain knowledge about input message text and the domain of the possible response actions. The input system interfaces with message text systems such as electronic mail, and the output interface encompasses a variety of appropriate response actions including message text responses, message forwarding, summaries of message text for later review, interfaces to printers and facsimile machines, and addition of items to workflow systems.
A preferred embodiment of a message text understanding and response system according to the present invention is shown in the figures. Using this system, the intent of a writer of an input text message is determined from the text of the message, and the system responds to that intent in a way that is appropriate to the system operator's domain. In a simple case, a company's customer service department might use the system to automatically act on messages received from customers. The system determines the customer's intent, to the extent that it relates to the company's customer needs, and takes an action appropriate for that intent. If the intent of the customer (as evidenced by the text of the message) is a request for information on a particular product, the system might respond by sending a message back to the customer with the requested information. However, in more complex or ambivalent cases, various answers are possible. Also, the system might take an action which is not what the customer intended, but what the company intends for that situation.
The system recognizes phrase types and intents from input text and maps these to domain knowledge pertaining to common kinds of intents. The intents are in turn mapped to actions. Phrase types, intents and actions have an association where each is dependent on the others for overall meaning and utility. It is the conjunction of phrase types, intents and actions which form single associations which constitute a reasonable response to an input text message. The input message arrives at the system via electronic mail, network transport, or any number of well-known communication methods. The source of the input message is referred to as the writer. The writer is usually a person, but might also be another computer system. The action of the system in response to the input message can take a variety of forms, such as sending a response message to the writer, forwarding the message to another person or computer system for further handling, summarizing the message for later handling, outputting to printers or facsimile machines, or adding items to workflow systems.
FIG. 1 illustrates a network 10 in which an embodiment of the present invention is implemented. In network 10 , a customer system 12 is coupled to a server 16 either directly or over a network to send input message 14 . Use of customer system 12 is not limited to internal customer messaging, but can be used by anyone who wishes to communicate with the customer's company. Customer system 12 sends input message 14 to server 16 for processing. If a network is interposed between customer system 12 and server 16 , it could be a local area network, the Internet, an intranet, an extranet, or the like. Server 16 is adapted to take an action based on an internal knowledge base and the text of query message 14 . If the action is a response message 18 , that response message 18 is sent to customer system 12 . If the action is an external action or a forwarded message, those are sent to other systems (not shown).
Network 10 is also shown including a management system 20 including end-user management tools for modifying the knowledge base (not shown; see FIG. 12) in server 16 according to the response policies and business practices of the operator of server 16 . In the preferred embodiment, server 16 is the Brightware™ BrightResponse™ automated message understanding and response system developed by Brightware, Inc. of Novato, Calif. and preferably customized to the particular business needs of the operator of the server (the “system operator”).
FIG. 2 shows server 16 and management system 20 in greater detail. Management system 20 is shown comprising a lexical analysis tool 30 , a default knowledge base 31 , storage for knowledge base recommendations 32 and editors 34 for editing the lexicon, rules and objects. Before the regular automatic response operation, the lexical analysis tool 30 is fed a corpus of training messages and provided with default knowledge base 31 to arrive at recommendations for the contents of the knowledge base to be used in processing messages. Those recommendations can be edited by the end user (the operator of server 16 ) before they are included in the knowledge base. The knowledge base ( 36 ) is shown as part of server 16 , along with a message processing module 38 and a response viewer module 40 . Message processing module 38 uses knowledge base 36 and the input message to determine what actions to take, be it sending back message 18 , sending a request to response viewer module 40 and/or adding to a processing log 42 .
Generally, customer system 12 , server 16 and management system 20 are general purpose computer systems programmed according to their use and comprising one or more central processing unit, memory (ROM and RAM), and associated peripheral equipment, such as disk drives, compact discs, printers, facsimile machines and video display terminals. The programs used to implement the programming might reside in memory, in one of the storage devices, or a combination of the two. Knowledge base 36 is maintained on a disk drive and/or memory within server 16 , but might also include portions resident on remote storage systems.
Referring now to FIG. 3, details of message processing module 38 and its connections to knowledge base 36 are shown therein. The details of a component of knowledge base 36 , an extraction rule set 50 and an initial module of message processing module 38 , a natural language extraction (NLE) module 52 , are shown in FIG. 4 .
FIG. 4 shows NLE module 52 comprising a regular expression module 60 , a word extraction module 62 , spelling module 64 , a morphology module 66 , and a phrase-type matching of module 68 . Extraction rule set 50 is shown comprising a regular expression lexicon 70 and overall lexicon 72 and a phrase type lexicon 74 . The process of understanding and responding to text messages begins with accepting the input text message, which is first processed by NLE module 52 . One possible ordering of modules within the NLE module shown in FIG. 4 is that the regular expression module 60 receives the input text message and reads from regular expression lexicon 70 . Because the input text may include, in addition to natural language free-form text, other data constructs such as documents, graphic objects, field formatted text, and control characters, the input text is scanned for these data constructs which are not free-form text. All formatted data constructs are tagged for later use. As each module operates on the input message, it adds tags to the message. These tags are used in later stages to determine the intents present in the message and message classification. Depending on implementation, these tags may be inserted directly into the text of the message, or may be separated into an adjoining data structure. Regular expression module 60 looks for regular expressions which are known to regular expression lexicon 70 . For example, regular expression lexicon may have rules for identifying regular expressions such as telephone numbers, e-mail addresses, customer account numbers, and part numbers. Regular expression module 60 identifies instances of the regular expressions represented in regular expression lexicon 70 , it inserts tags into the message to indicate those regular expressions. Once a regular expressions is identified, it is excluded from further analysis in the free-form text. Modules 62 , 64 and 66 then continue to operate on the free-form text.
Word extraction module 62 identifies the bounds of words. Most of the bounds are words can be identified by looking for one or more consecutive characters separated by a space character, but word extraction module 62 also identifies word boundaries in more unusual situations, such as where punctuation and typing errors might interfere with normal parsing. Spelling module 64 identifies incorrectly spelled words and adds tags to those words identifying the correct spelling. Characters and words not found in any phrase type or regular expression are ignored. An overall lexicon 72 contains words from a general dictionary as well as words specific to the system operator's business.
Morphology module 66 uses overall lexicon 72 to transform the words into their regularized form. For example, morphology module 66 might convert the word “said” to “say” in an effort to simplify the message. As should be apparent, modules 60 , 62 , 64 , and 66 can operate on the input message non-sequentially. For example, after the spelling module removes a typographical error, the result may match a regular expression which was not earlier matched, in which case regular expression module 60 would add additional regular expression tags when the message is revisited.
Once the regular expressions are tagged, the word boundaries are identified, spelling is corrected, and text is regularized, the text is compared to a regularized list of phrase types from phrase type lexicon 74 . As each phrase type is identified in the input message, phrase type tags are added to the message. Depending on the lexicon used and the input message, any given word may be tagged as part of one phrase type, multiple phrase types, or no phrase type. In the preferred embodiment, none of the operations performed by the various modules of NLE module 52 delete the original text, that is, characteristics other than phrase type and regular expression can be tagged to words in addition to phrase type and regular expression.
Referring back to FIG. 3, the input message with all the phrase types identified is passed to an intent matching module (“IMM”) 54 . In the preferred embodiment, the elements of the input message which are not associated with any identified phrase type are ignored and need not be passed on to IMM 54 . IMM 54 identifies, for the phrase type(s) present in the input message, which intents are composed of the most similar phrase types. Generally, the intents are a set of typical cases for which appropriate response actions can be established. The system evaluates the match for each of the phrase types and for other data extracted from the input message text to determine which of the intents in knowledge base 36 is closest to the intents expressed in the input message text. An input message text may have several intents. These are identified and stored on an intents list associated with the input message text.
In addition to identifying the intent or intents of the writer, IMM 54 also will try to identify message characteristics of interest to the system operator. These characteristics may or may not be part of the writer's intent, or even be things the writer is aware of. For example, message processing module 38 might use phrase types and other deductions to determine whether the message is in a foreign language, is a continuation of an earlier message, or is a message with legal ramifications. This characteristic classification is appended to the accumulated information about the input message.
The confidence in the system's intent determination is represented by a variety of mechanisms, such as threshold scoring, which vary according to domain. In some situations only approximate information is needed, while in others information must be exact and conclusive. Important factors in confidence of the interpretation of an input message text include: the exactness of matches to a set of phrase types indicating intent, whether the information about the input text message supports ambiguous interpretations, and the sensitivity of the subject matter (for example issues of toxicology raises the sensitivity of a message).
Information is stored in the system's knowledge base to understand and interpret incoming messages, but the system is also able access information in external knowledge bases, which can be located at any location available on a network or internet. A typical example would be the checking account status of the writer of the incoming e-mail. This information can be used to determine response actions.
Searches and reasoning processes in the system as a whole are embodied in business and linguistic rules and functions specified by the system operator, using a combination of object editors, rule editors, browsers, and other tools which manipulate the knowledge base using the system operator's terminology, rather than computer languages.
Once the intents are identified, the message and the intents list is passed to an action mapping module (“AMM”) 55 , which generates a list of proposed actions. In the course of processing the input message text, decisions are made to add actions to a list for later evaluation. Actions are selected from among those deemed appropriate by the system operator, as expressed in a policy rule set 51 . These tentative actions are discovered as the message is processed, and the actions are stored on an action list until all the intents of the message and other cogent information is identified. Once all plausible actions are tentatively identified, the actions are examined to determine if they are complete, correct and do not conflict with each other. For example, a tentative, general action which specifies the writer be answered automatically might conflict with an tentative action specifying that the specific intent must be answered manually. Actions which cannot, or should not, be executed are marked for non-execution and the remaining actions are executed. This process of resolving the correctness and consistency of the actions is performed by an action resolution module (“ARM”) 56 which has as its input the intents identified in the message, as well as results from application of the policy rule set 51 .
If one of the actions is a response to the writer, the composition of the response message text may include an explicit recitation of the writer's intent as determined by the system, as well as other phrases and extracted information relating to those intents. The actions taken are determined by ARM 56 , and executed by an action execution module (“AEM”) 57 , with consultation of policy rule set 51 . Depending on the list of actions, multiple responses and/or other actions may be initiated by AEM 57 . In the preferred embodiment, a response to the writer will give an indication of how the writer's message was interpreted, in addition to giving the response. Thus, a response message may include a paraphrasing of the system's understanding of the intents, a statement about the nature of the response, and the response itself. In some systems, for debugging purposes or legal reasons, the input message text, response results and other processing information might be logged for later analysis, reporting or record keeping.
Optionally, the response will include tags which can be used to reference that response. This is useful where the writer determines their intentions were not correctly addressed by the system. If that occurs, the writer can send an additional message, possibly explicitly referencing the previous correspondence using the reference tag found in the response, in an attempt to clarify their intent. In addition, the response might include questions added by the system to query the writer on the efficacy of the response.
Optionally, management system 20 provides a set of methods and tools which assist the system operator in determining appropriate phrase types, intents, regular expressions and other data for knowledge base 36 , using a corpus of message texts. The purpose of these methods and tools is to simplify the process of tailoring the information which is specific to the system operator's environment that is stored by the system for determining intents and message classifications. The system operator supplies a set of input messages which they have decided represent typical examples of input message intents that the system will later respond to automatically. The tool analyzes the entire text of the input message corpus determining which particular characters, words, and regular expressions are relevant to intents as specified by the system operator. One tool starts the analysis process not with an empty knowledge base, but a predefined knowledge base of phrase types, regular expressions and intents which are known to be generally useful for typical message classification. This tool searches for any missing information in each message in the corpus needed to reach the system operator specified intents. Management system 20 analyzes the input message text corpus as a whole, applying classification techniques similar to those which are implemented when the system will be answering single input message texts. Management system 20 determines the correspondence between statements made by the system operator about the input message text corpus and determines whether those statements increase the overall number of input message texts whose actions and classifications can be determined above a threshold of certainty. Management system 20 also searches for phrases and regular expressions which were not specified by the system operator and were not in the static knowledge base, but which could be used to complete a set of phrase types appropriate to particular intents. A list of suggested additions and deletions to the system's knowledge base is given to the system operator. These suggestions are then included in the system by use of the editors 34 , browsers and editing tools.
FIGS. 5 ( a )-( b ) show an example of an input message 102 being processed by the system described above. The input message is processed by NLE module 52 to generate tags associated with portions of the input message. As described above, the tagged elements are the elements used to process the input message; the remaining text of the message (shown by shading in FIGS. 5 ( a )-( b )) need not be used.
As shown in FIG. 5 ( a ), NLE module 52 uses a regular expression list 104 and a phrase types list 106 in assigning tags to a message. An example of regular expression list 104 and a phrase types list 106 , as might be used in the example of FIG. 5 ( a ), is presented in Table 1 and Table 2, respectively. Those lists contain only a few entries, but nonetheless illustrate the process. In an actual application, the lists would typically have many more entries.
TABLE 1
Regular Expression List
Expression
Type
http://*{/*}>
URL
###-###-####
Phone
[a-zA-Z]@*.*
Email
. . .
. . .
TABLE 1
Regular Expression List
Expression
Type
http://*{/*}>
URL
###-###-####
Phone
[a-zA-Z]@*.*
Email
. . .
. . .
Regular expression list 104 is used to isolate and identify character strings in the message which match the expressions in the list. If a regular expression from list 104 is matched in the message, the matching text is tagged with a “RegExp” tag. In the example shown, an e-mail address is matched and tagged with a “RegExp=Email” tag. Of course, in an actual application, more complex regular expressions could be listed, such as a regular expression that identifies not only that it is an e-mail address, but that it is the “To:” address. Other regular expressions will locate telephone numbers, or even the signature lines of an e-mail message.
Prior to the regular expression parse, the message might be pre-processed for structured data. For example, if attachments are included or data is included in the message in a structured format, such as “HTML” forms data, comma delimited data records, or an attached spreadsheet, that structured data is identified. Preferably, that structured data is flagged such that NLE module 52 does not need to process it.
After the regular expressions are tagged, the remaining text is scanned for phrase matches. In the preferred embodiment, spelling is corrected to the extent possible and words are reduced to their base morphological forms so that phrase matching is simplified. The matched phrases are tagged with phrase type (“PT”) tags which identify the type of phrase. When deciding on intents and actions, the system uses the phrase type and the phrase value. The corresponding phrase values are shown in FIG. 5 ( a ) surrounded by a dotted line. Several phrase types from list 106 are shown in Table 2. The phrase type “INFO_PHRASE” is used to identify words and phrases relating to information. “PRODUCT_PHRASE” is used to identify words and phrases associated with a particular product. In this example, the product part number is spelled out (“PT- 144 ”) making detection of it simple. However, some product phrases might be more complex, such as the phrase “your new four-door passenger van” which would be identified as a phrase of type “PRODUCT_PHRASE” even though no part number was mentioned. However, if the system was set up to address customer service for a non-automotive company or the application was such that it had no actions to take in which it mattered that the message writer is interested in a car, that phrase would not match any phrase type and would thus be ignored.
The other phrase type found in message 102 is “trade show” which is a “MARKETING_EVENT” phrase type. In this hypothetical, the system operator has added that phrase type to catch any messages expressing interest in the trade show so that tickets could be sent to the writer. Of course, as the message makes clear at least to a human reader, since the trade show was in the past, the system should not go so far as to actually send tickets, since it is too late to do so.
Also shown in Table 2 is a “PROFANITY_PHRASE” phrase type. This phrase type does not appear in message 102 , but for messages which do have the profanity in them, the system can identify them. In such a case, the action taken might not relate to the intent of the message. For example, the message might contain a request for a refund and profanity. While the main intent of the writer is to get a refund, the classification of the system operator with respect to this message may well override the writer's intent. For example, the message might be classified not necessarily as a request for refund, but as a complaint. In this case, the existence of that phrase type might trigger an intent to discourage the writer or an intent to identify and respond to any complaints the customer might have. Those intents would, in turn, trigger an action of sending a polite response to the writer saying their message was classified as a complaint.
Although each of the identified regular expressions and phrase types are associated with separate text, there is nothing to prevent a word from being part of multiple, overlapping phrase types.
In any case, once the regular expressions and phrase types are identified, the analysis process continues, as shown in FIG. 5 ( b ). Using the tagged phrases and regular expressions, the system performs any necessary database lookups. For example, a database lookup might be used to determine the customer's full identity just from a name in the message or the e-mail address. These database lookup results and other additional data fields are attached to the message as additional data 110 . Of course, the additional data does not need to be explicitly attached to the message, but could be merely associated with a message or have a pointer to a message.
The message with its tags and additional data are then provided to intent matching module 54 , which identifies the writer's and system operator's intents using an intent list 114 . An intent list contains a set of intent cases. In the example shown, we assume that intent list 114 contains an intent entry such as:
Information_Request_Intent: <info_Phrase> and <product_phrase>
which would identify one of the writer's intents as being an information request whenever an information phrase and a product phrase are found in a message.
The identified intents, the tags and their values are provided to action mapping module 55 , which continues generating an action queue 120 based on the intents. For example, based on the intents which might have been associated with message 102 , action mapping module 55 might have determined that the appropriate actions were to get product information to send to the writer, create a response letter template, reply to the writer, forward a copy to marketing (if the customer is a new customer), add the customer to the customer database (if a new customer), prepare electronic trade show tickets (or, if the tickets are not electronic, initiate the mailing process), etc. The retrieval of product information and creation of reply letter are triggered by a product information request intent, while the forwarding to marketing is based on an intent rule triggered by the system operator's intent.
Action queue 120 and the tagged elements of message 102 are passed to action resolution module (“ARM”) 56 to resolve inconsistent actions on action queue 102 . Of course, the entire message 102 might be passed along for use as uninterpreted text, as might be used to form a “quoted reply” type e-mail message.
In the example shown in FIG. 5 ( b ), ARM 54 will note that the date of the trade show has already passed and the action of sending tickets is deleted from action queue 120 . Other intents could eliminate or override other actions. For example, if message 102 had contained profanity and one of the intents of the system operator mapped the intent CENSURE_WRITER with the phrase type PROFANITY_PHRASE, the action for that intent might be to send a censure response and delete all other actions from action queue 120 . Many variations of these structures for specific applications will be apparent to one of skill in the art after reading this disclosure.
Once the actions to be taken are resolved, a list 122 of actions to take is passed to action execution module (“AEM”) 57 , which performs the actions listed on list 122 , such as creating a response 130 . A preferred response 130 includes all or part of the original message, information satisfying the writer's intent (if the writer's intent was to get a response of some sort) and an indication of how the message was interpreted. One way to show how the message was interpreted is to show the tags and the values for tagged regular expressions and tagged phrase types.
The above description discloses how to make and use embodiments of an automated text understanding and response system. As explained herein, the task of interpreting message text is greatly simplified by not processing text with which no action is to be taken. In such a system, a system operator familiar with their business, but not necessarily with the details of how to construct an electronic dictionary, could compile rules mapping intents to actions and phrase types mapping to intents, as well as specifying the conditions for system operator intents.
The above description is illustrative and not restrictive. A number of interesting variations of the invention will become apparent to those of skill in the art upon review of this disclosure. Merely by way of example, the writer and system operator need not be a customer and business, respectively. The writer could be a person doing research on a topic on which the system operator has a special expertise. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents. | A message understanding and response system recognizes and answers messages based on the message writer's intent in unconstrained natural language text messages. The system has a set of knowledge bases with linked domain specific words, phrases, and regular expressions relating to the domain of the writer and the domain of the respondent. The writer's domain is represented by special purpose lexicons linked to representations of typical intents. The typical intents are linked to a domain knowledge base of typical and appropriate respondent actions. The system is initialized by manually classifying a training text corpus according to the respondent's policies. A lexical analysis tool with prototypical intents and phrases indicating intents is applied to the training text corpus, which includes the domain specific characteristics of both the writer and the respondent. The output results are an operable knowledge base which is a conjunction of keywords used to communicate between the two domains of the writer and the respondent. During automatic operation, the input text is pre-processed to remove irregularities in a manner similar to how the data in the training text corpus was regularized. Sets of extracted keywords and concepts are matched against the sets of stored, pre-classified keywords and concepts, producing a list of intents. The intents and other extracted features are then mapped to appropriate actions as defined by the system operator. The actions use the common linked domain knowledge terms to formulate a textual reply which is tailored to and answering the intent of writer of the input message. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to heavy-duty ground transport vehicles, in particular heavy-duty automated guided vehicles for transporting ISO-containers.
German patent DE 42 03 778 C2 discloses an automated ground vehicle having a manipulator disposed thereon. By means of the ground vehicle, the manipulator can be moved automatically between different work stations in order to perform assembly tasks at these locations. The ground vehicle is driven via a replaceable nickel-cadmium battery. The battery can be changed automatically at a changing station if it has to be recharged. For this purpose, a vehicle frame of the ground vehicle is provided with a battery space, in which there are disposed guide rails which are aligned transversely with respect to the longitudinal direction of the ground vehicle. The underside of the battery is provided with rollers which roll on the guide rails. In order to prevent the battery from moving along the guide rails during operation of the ground vehicle, the vehicle frame is provided with a pin which is pretensioned in a resilient manner in the direction of the battery and engages into a recess in the battery during operation of the ground vehicle. In order to change the battery, the pin can be lowered hydraulically. The battery, thus released, can be pulled laterally out of the vehicle frame along the guide rails by means of a changing apparatus. For the purpose of the changing operation, the ground vehicle travels automatically to a changing station.
Furthermore, German patent application DE 10 2007 039 778 A1 discloses a heavy-duty automated guided ground vehicle for ISO-containers. The transport vehicle comprises a vehicle frame, on which at least one lifting platform is disposed, which can be raised from a lowered transport position to a raised transfer position or vice versa via at least one lifting drive. Typically, such transport vehicles are driven by a diesel engine.
SUMMARY OF THE INVENTION
The present invention provides a heavy-duty ground transport vehicle, in particular a heavy-duty automated guided vehicle for ISO-containers, having a travelling drive, which achieves improved environmental friendliness by virtue of a battery that is disposed in the heavy-duty transport vehicle for providing the travelling drive with power. A significant advantage of the heavy-duty transport vehicle operated by means of a battery, in the form of a traction battery, is that local emissions of pollutants can be avoided completely and sound emissions can be reduced considerably. As a consequence, the impact upon the immediate environment is considerably lower. The efficiency of the drive train can also be increased considerably. As a result, the total amount of power required to operate the vehicle can be reduced. Therefore, on the one hand, environmental compatibility is further improved and on the other hand operating costs can be reduced. The battery typically requires less maintenance than a diesel generator unit which has also hitherto been used for providing the electrical driving power. This makes it possible to reduce maintenance costs. Since the current for recharging the batteries can be generated from different power sources, the operation of the vehicle may be independent of the availability and the costs of diesel fuel.
In one aspect, the disposability of the heavy-duty transport vehicle may be increased by releasably connecting the battery to the heavy-duty transport vehicle for battery-changing purposes. The charging procedure for the battery can thus be performed outside the heavy-duty transport vehicle, and the heavy-duty transport vehicle can continue operation with a charged replaceable battery.
In another aspect, a rapid battery change is rendered possible by permitting, for changing purposes, the battery to be moved in and out transversely with respect to the longitudinal direction of the heavy-duty transport vehicle.
In still another aspect, the heavy-duty transport vehicle includes several front wheels and rear wheels, the front wheels being drivable by a first electric motor and the rear wheels being drivable by a second electric motor. In this case, the battery may be disposed between the front and rear wheels.
In order to make it even easier to change the battery, the heavy-duty transport vehicle may include a vehicle frame having an installation space for the battery, the installation space being open at the bottom and at the sides of the heavy-duty transport vehicle.
In constructional terms, it may be provided that, as seen in the longitudinal direction of the heavy-duty transport vehicle, carrier rails are disposed at the front and rear edge of the installation space and extend transversely with respect to the longitudinal direction of the heavy-duty transport vehicle, and the battery is supportable on the carrier rails.
Optionally, the battery may be attached in a particularly convenient manner to the heavy-duty transport vehicle by virtue of the fact that the battery is substantially cuboidal, sidewalls of the battery which are at the front and rear as seen in the longitudinal direction of the heavy-duty transport vehicle have support elements disposed thereon which protrude in each case from the front and rear sidewall and the battery is supported on the carrier rails via the support elements.
In relation to the change of battery, the heavy-duty transport vehicle can be formed advantageously in a passive manner, since, in the region of the support elements and the carrier rails, centering elements are disposed which, when the battery is moved into the installation space and is lowered onto the carrier rails, align the support elements with the carrier rails. It may also be provided that electrical contact elements are disposed on the battery, and in the region of the carrier rails electrical counter-contact elements are disposed, which contact elements can be electrically coupled or connected automatically by lowering the battery onto the carrier rails.
A high degree of reliability of the heavy-duty transport vehicle may be achieved by forming the battery as a lead battery, such as one that weighs between 6 t and 10 t, particularly since there is extensive experience in the use of lead batteries in vehicles.
The transport vehicle of the present invention may be particularly suitable or advantageous as a heavy-duty transport vehicle having a permissible total weight of at least 40 t.
These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view a heavy-duty automated guided ground vehicle for ISO-containers in accordance with the present invention;
FIG. 2 is a bottom perspective view of the heavy-duty transport vehicle of FIG. 1 ; and
FIG. 3 is a side elevation of the heavy-duty transport vehicle of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and the illustrative embodiments depicted therein, a heavy-duty automated guided ground vehicle 1 is provided for transporting containers 5 such as ISO-containers. In the illustrated embodiment, heavy-duty transport vehicle 1 has an empty weight of about 35 tonnes. Added to this is the weight of the ISO-container 5 to be transported, so that in the laden state a total weight of about 85 tonnes is achieved. The transport vehicle 1 , which in the illustrated embodiment is formed as a four-wheel vehicle, includes a vehicle frame 2 on which two front wheels 4 a are mounted on a common front axle 3 a , and two rear wheels 4 b are mounted on a common rear axle 3 b . The four wheels 4 a , 4 b are provided with respective tyres. The vehicle frame 2 supports a planar platform 4 , which serves to receive the ISO-containers 5 that are to be transported by the vehicle.
For purposes of this description, a heavy-duty transport vehicle is understood to be a vehicle which can transport a payload of at least about 15 t, and preferably at least about 20 t. Loads for the heavy-duty transport vehicles include ISO-containers and swap containers, for example. Laden swap containers can generally weigh up to about 16 t. In the laden state, ISO-containers typically weigh about 20 t to 80 t. Transport of ISO-containers may be preferred since ISO-containers are generally understood to be large standardised containers having standardised lifting points or corners for load receiving members. A heavy-duty transport vehicle which travels empty or transports an empty ISO-container or swap container is also to be included in this category, as long as this vehicle can transport a payload of at least about 15 t, and preferably at least about 20 t. It can also be the case that such heavy-duty transport vehicles operate in a mixed operation, i.e. can transport not only ISO-containers or swap containers but also other loads such as semitrailers, swap trailers, trailers, heavy goods vehicles or tractor trucks, for example.
The vehicle frame 2 comprises an installation space 6 for a battery 7 ( FIGS. 1-3 ). The installation space 6 begins below the platform 5 of the vehicle frame 2 and is open at the bottom in the direction of the ground 8 and on the sides 1 a of the heavy-duty transport vehicle 1 . Moreover, the installation space 6 is disposed between the front and rear wheels 4 a , 4 b of the heavy-duty transport vehicle 1 . Since the installation space 6 is open towards the right and left side 1 a as seen in the longitudinal direction L of the heavy-duty transport vehicle 1 , in order to recharge the battery 7 outside the heavy-duty transport vehicle 1 , the battery 7 can be changed in a convenient manner by means of a movement transverse to the longitudinal direction L of the heavy-duty transport vehicle 1 in a loading and unloading direction E ( FIGS. 1 and 2 ). Moreover, the installation space 6 is open at the bottom, which means that the battery 7 can be loaded and unloaded by forklift truck-like handling equipment. The battery 7 may typically be formed as a lead battery having a weight of about 8 to 9 tonnes. This battery 7 can be used to operate the heavy-duty transport vehicle 1 for about 6 to 8 hours.
FIG. 2 illustrates a perspective view from below of the heavy-duty transport vehicle 1 in accordance with FIG. 1 . In addition to the elements already described with respect to, FIG. 2 additionally shows Referring now to FIG. 2 , a travelling drive of the heavy-duty transport vehicle 1 includes a front electric motor 9 a , a front transfer gearbox 10 a , a rear electric motor 9 b , and a rear transfer gearbox 10 b . The front electric motor 9 a is attached in the region of the front axle 3 a under the vehicle frame 2 and is attached centrally as seen in the longitudinal direction L of the heavy-duty transport vehicle 1 . The rear electric motor 9 b is attached in the region of the rear axle 3 b under the vehicle frame 2 and is attached centrally as seen in the longitudinal direction L of the heavy-duty transport vehicle 1 , The front electric motor 9 a drives the two front wheels 4 a via the front transfer gearbox 10 and the rear electric motor 9 b drives the two rear wheels 4 b via the rear transfer gearbox 10 b . The heavy-duty transport vehicle 1 thus has a four-wheel drive.
Optionally, and as shown in FIG. 2 , space is provided between the battery 7 and the front axle 3 a for the suspension of switch cabinets 11 under the vehicle frame 2 in order to receive control components.
As best shown in FIG. 3 , battery 1 is suspended on the vehicle frame 2 of the transport vehicle 2 via carrier rails 2 a . In the illustrated embodiment, two carrier rails 2 a are disposed at a mutual spaced interval, are aligned horizontally with respect to each other, and are attached at one height to the vehicle frame 2 via brackets 2 b . The carrier rails 2 a define the installation space 6 at the front and rear as seen in the longitudinal direction L of the vehicle. In order to be able to suspend the battery 7 on the carrier rails 2 a , the cuboidal battery 1 has, on its front and rear sidewalls 7 b , 7 c and in the region of the corners of the battery 7 , laterally projecting suspension elements 7 a which, in the operating state of the battery 7 , are supported on the carrier rails 2 a of the heavy-duty transport vehicle 1 . By means of this type of suspension of the battery 7 within the vehicle frame 2 and in the upper region thereof, a forklift truck or other lifting apparatus can easily be driven underneath the battery 7 in a convenient manner Then, by means of a movement of the forklift truck or other lifting apparatus in a vertical lifting and lowering direction S, the suspension elements 7 a can be lifted off the carrier rail 2 a and subsequently the battery 7 can be moved out of the transport vehicle 1 in an insertion and removal direction E. It is also provided that, by means of the vertical movement in the lifting and lowering direction S, the battery 7 (which is aligned with the carrier rails 2 a and is protected from sliding by means of centering elements), is unlocked by the centering elements. In addition electrical contact elements are provided on the battery 7 and counter-contact elements are provided in the region of the carrier rails 2 a for electrically connecting the battery 7 to the travelling drive. The advantage of this is that in relation to unlocking and contact removal, the heavy-duty transport vehicle 1 can be formed in a passive manner.
The intended fields of application for the heavy-duty transport vehicles described above and the associated battery-change systems would typically include ISO-container handling in docklands and in intermodal traffic between road and rail, for example.
Although the present invention has been described primarily with reference to a heavy-duty ground transport vehicle for the transportation of ISO-containers, it is envisioned that the principles of the present invention may be practiced to transport other heavy loads, such as slabs or coils, in metallurgical engineering, steel engineering and rolling mill engineering, for example.
Changes and modifications to the specifically described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law including the doctrine of equivalents. | The invention relates to a heavy-duty ground transportation vehicle, in particular an unmanned guided heavy-duty transportation vehicle for ISO containers, which is environmentally friendly. This is achieved by arranging a battery in the heavy-duty transportation vehicle to supply power to a travelling drive of the vehicle. The battery is typically a lead battery of considerable weight, and is releasably connected to the transport vehicle in a manner that permits changing the battery (e.g., exchanging a depleted battery for a fresh battery) and recharging the depleted battery at a location outside the vehicle. The battery can be moved into and out of transport vehicle transversely with respect to a longitudinal direction of the vehicle. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to provisional application 61/468,427 filed on Mar. 28, 2011.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not Applicable
FIELD OF THE INVENTION
[0005] This invention relates to devices that assist a user in launching a kayak off of a retractable platform.
BACKGROUND OF THE INVENTION
[0006] Many consumers may have difficulty getting into and stepping out of their kayaks. The docks from which consumers must step to enter their kayaks may be elevated, requiring users to take large steps down to reach their kayaks. This can cause users to lose their balances and slip. When leaving the kayaks, users may need to hoist themselves up, leading to painful strained muscles. An effective, safe solution is necessary and is provided by the claimed invention.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention includes methods, systems, and other means for a retractable platform to assist a user with launching a kayak. The retractable platform comprises a support frame assembly mechanically coupled to a step assembly. The support frame assembly is mechanically coupled to a platform assembly, a hand crank, a hand rail and a platform assembly.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0008] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0009] FIG. 1 is a perspective view of the invention shown in use.
[0010] FIG. 2 is a perspective view of the invention illustrated with optional planking.
[0011] FIG. 3 is a perspective view of the invention illustrated without optional planking for clarity.
[0012] FIG. 4 is an exploded view of the invention illustrating major assembly components.
[0013] FIG. 5 is a side view of the invention illustrated in extended position.
[0014] FIG. 6 is a side view of the invention illustrated in partially retracted rotational position.
[0015] FIG. 7 is a perspective view of an alternate embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Embodiments of the present invention overcome many of the obstacles associated with launching a kayak in shallow water, and now will be described more fully hereinafter with reference to the accompanying drawings that show some, but not all embodiments of the claimed inventions. Indeed, the invention may 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 satisfy applicable legal requirements. Like numbers refer to like elements throughout.
[0017] FIG. 1 shows the invention in use. User 10 desires to launch kayak 16 in water 12 from dock 14 . The present invention, retractable platform 24 , meets that need. Retractable platform 24 comprises support frame assembly 18 which further comprises dock mount 32 . Dock mount 32 is immediately adjacent to dock 14 and is mechanically coupled to hand crank post 30 which is further mechanically coupled to hand crank 26 . Hand crank 26 comprises crank line 54 and crank handle 56 . Crank line 54 mechanically couples hand crank 26 to hand rail 58 (not shown) which is further mechanically coupled to platform assembly 22 as shown in more detail in FIG. 5 . A user can utilize hand crank 56 to lift platform assembly 22 as shown in FIG. 6 .
[0018] Platform assembly 22 is mechanically coupled to step assembly 20 as shown in FIG. 3 . Here, step assembly 20 is shown comprising planking 60 , though it can also comprise diamond grating 62 as shown in FIG. 7 . Planking 60 is mechanically coupled to support frame assembly 18 as shown in FIG. 2 .
[0019] FIG. 2 shows retractable platform 24 in more detail. As noted above retractable platform 24 comprises support frame assembly 18 mechanically coupled to step assembly 20 which is further mechanically coupled to platform assembly 22 . Support frame assembly 18 comprises dock mount 32 which is mechanically coupled to mounting frame 34 and hand crank post 30 . Step assembly 20 is mechanically coupled to mounting frame 34 at step pivot fastener hole 52 as shown in FIG. 4 .
[0020] Platform assembly 22 comprises platform frame 42 which is mechanically coupled to left platform side aim 44 , right platform side arm 44 and further mechanically coupled hand rail 58 by left bracket 48 and right bracket 48 . Left platform side arm 44 is mechanically coupled to mounting frame 34 by left platform arm 36 and left step pivot fastener hole 50 as shown in FIG. 4 . Similarly, right platform side arm 44 is mechanically coupled to mounting frame 34 by right platform arm 36 and right step pivot fastener hole 50 as shown in FIG. 4 . Here, planking 60 is mechanically coupled to step assembly 20 and platform assembly 22 .
[0021] As noted above, hand crank 26 comprises crank handle 56 and is mechanically coupled to hand crank platform 28 . Hand crank platform 28 is mechanically coupled to hand crank post 30 , which is further mechanically coupled to mounting frame 34 .
[0022] FIG. 3 shows a perspective view of the invention without planking 60 . While a variety of materials can be used to make the components of retractable platform 24 , the following materials have been notably effective: platform frame 42 can be made from 1.5 inch by 1.5 inch by 0.188 inch steel tube. Step assembly 20 also can be made from 1.5 inch by 1.5 inch by 0.188 inch steel tube. Additionally, step pivot fastener 36 and platform pivot fastener 38 can be made from 1.5 inch by 1.5 inch by 0.188 inch steel tube. Mounting frame 34 can be made from 2 inch by 2 inch by 0.188 inch steel angle. Deck mount 32 can be made from 0.188″ by 3″ hot rolled flat steel bar.
[0023] FIG. 4 shows the mechanical couples mentioned above in more detail in an exploded view of the invention. Cross brace 66 provides additional support to mounting frame 34 . To mechanically couple step assembly 20 to mounting frame 34 , a user must first mechanically couple right step stop 64 and left step stop 64 to mounting frame 34 . After that, a user must mechanically couple left step arm 38 and right step arm 38 to mounting frame 34 . Left step arm 38 further comprises left step pivot fastener hole 52 . Right step arm 38 further comprises right step pivot fastener hole 52 .
[0024] A user then inserts first left bolt 70 into first flange bearing 72 through left step pivot fastener hole 52 into second flange bearing 72 , into third flange bearing 72 , into fourth flange bearing 72 into first nut 74 and into second nut 74 completing left step connection. Subsequently, a user inserts first right bolt 70 into fifth flange bearing 72 through right step pivot fastener hole 52 into sixth flange bearing 72 , into seventh flange bearing 72 , into eighth flange bearing 72 into third nut 74 and into fourth nut 74 completing right step connection.
[0025] To mechanically couple platform assembly 44 to mounting frame 34 , a user must first mechanically left platform arm 36 and right platform arm 36 to mounting frame 34 . Left platform arm 36 further comprises left platform pivot fastener hole 50 . Right platform arm 36 further comprises right platform pivot fastener hole 50 .
[0026] A user then inserts second left bolt 70 into ninth flange bearing 72 through left platform pivot fastener hole 50 into tenth flange bearing 72 , into eleventh flange bearing 72 , into twelfth flange bearing 72 into fifth nut 74 and into sixth nut 74 completing left platform connection. Subsequently, a user inserts second right bolt 70 into thirteenth flange bearing 72 through right platform pivot fastener hole 50 into fourteenth flange bearing 72 , into fifteenth flange bearing 72 , into sixteenth flange bearing 72 into seventh nut 74 and into eighth nut 74 completing right platform connection.
[0027] FIG. 5 shows a side view of the invention in use. As noted above, support frame assembly 18 is mechanically coupled to step assembly 20 and platform assembly 22 as shown in FIG. 4 . Support frame assembly 18 is also mechanically coupled to hand crank 26 . Here, support frame 18 comprises gusset plate 40 which is mechanically coupled to platform arm 36 and mounting frame 34 . Gusset plate 40 provides additional support to platform arm 36 .
[0028] In use, dock mount 24 is parallel and immediately adjacent to dock 14 (not shown). Mounting frame 38 will he perpendicular to dock 14 (not shown). The weight of dock mount 32 should be sufficient to keep retractable platform 24 in place. When user 10 operates hand crank 26 such that crank line 54 becomes loose, retractable platform 24 should appear as in FIG. 5 , which is, platform frame 42 is parallel to dock mount 32 and held in place by platform side arm 44 .
[0029] FIG. 6 shows retractable platform 24 in motion. As user 10 engages hand crank 56 in a clockwise manner, crank line 54 is wrapped around hand crank 26 and attachment point 58 is pulled toward hand crank post 30 . As this happens, platform frame 42 pivots about right platform pivot fastener hole 50 and left platform pivot fastener hole 50 causing platform frame 42 to gradually become parallel with mounting frame 34 . As this occurs, and platform frame 42 (or planking 60 if used) will become immediately adjacent to step assembly 20 and exert force upon step assembly 20 . This force causes step assembly 20 to rotate about right step pivot fastener hole 52 and left step pivot fastener hole 52 . As this occurs, step assembly 20 gradually becomes parallel with mounting frame 34 .
[0030] FIG. 7 shows an alternate embodiment of retractable platform 24 where a first diamond grating 62 is mechanically coupled to step assembly 20 . A second diamond grating 62 is mechanically coupled to platform base 42 . | This is directed to systems, processes, machines, and other means that enable a user to launch a kayak from a dock. The invention can easily be cranked into a portable or usable position depending on user preference and enable a user to easily launch a kayak. | 1 |
BACKGROUND OF THE INVENTION
Electrical measurements have become quite prevalent in medical and biomedical testing, and are used for monitoring a wide variety of functions of the human body. Some of these measurements are used in electrocardiograms, electroencephalograms and electromyograms. In order to make an electrical measurement, it is necessary to have a good electrical contact with the body to be measured through an electrode which is part of a half cell and is connected to a measuring apparatus.
It is recognized that a good electrode has certain important characteristics, such as, low impedance and stability. Since the electrode operates as a half cell, the half cell potential must be as stable as possible, with no influence on the half cell by perspiration or movement of the patient. The ultimate purpose of the electrode is the faithful transmission of the physiologically-generated electrical signal from the patient's skin to the recording and/or observing apparatus.
When the heretofore known electrode is used on a human body, it is necessary to prepare the area of the skin upon which the electrode is to be positioned. Typically, the skin is first cleaned; and then it is often abraded to provide a good electrical contact surface. The abrasion removes dead skin, which may impede the proper transmittal of an electrical signal to the electrode. A suitable electrolyte, generally in a gel form, is placed on the patient's skin. The electrode is then placed on the gel, forming a half cell, so that physiologically-generated electrical signals are observable. The electrical signal is carried to an amplifier and a recording and/or observing apparatus.
A very popular electrode construction which is commonly in use is one which utilizes a silver-silver chloride-chloride ion half cell. The silver-silver chloride-chloride ion half cell is generally formed either by compressing a mixture of silver and silver chloride powders and placing the compressed mixture in contact with a suitable electrolyte, or by forming a half cell by first electrochemically converting a surface of a silver piece to a silver chloride layer and placing a silver chloride layer into contact with an electrolyte.
These known electrodes generally have performed satisfactorily in many applications. However, these electrodes have certain undesirable properties. The electrolyte which is placed in contact with a patient's skin is generally in a gel form or a paste form. The paste is messy to handle, both for the operator and for the patient. The preparation technique causes irritation to the patient, especially when the skin is abraded for a good electrical contact. When prolonged readings are to be taken, the paste tends to dry, causing the impedance to increase at the electrode skin interface, thereby changing the observed signal by virtue of the failure to make a faithful transmission of the physiologically-generated signal. Furthermore, the electrical characteristics of these electrodes vary from electrode to electrode, so that there must be matching of electrodes and the measurements are limited to an AC amplifier. A DC amplifier is desirable in taking certain measurements, and particularly for electroencephalograms. The electrodes drift as the potential of the half cell changes in an erratic manner in relation to time. This often causes errors in measurement of signals and thereby gives a distorted view of the physiological signal-generating organ or body portion. A further problem which accompanies the known electrodes is that silver chloride cannot be kept in contact with a patient's skin for any prolonged time without causing irritation due to silver migration. Thus, prolonged continuous readings cannot be taken without subjecting the patient to tissue injury.
SUMMARY OF THE INVENTION
The present electrode does not use a paste or gel between a body surface and the electrode. It is an "isotonic calomel"t. electrode, utilizing a mercury-calomel admixture in contact with an isotonic saline solution. The electrolyte is a saline solution contained in a housing, with a cellophane diaphragm on one side of the housing retaining the electrolyte in the housing. The cellophane diaphragm is placed on the surface of a patient's skin, providing an ionic contact between the patient's skin and the electrode. The electrical half cell potential of the electrode is defined by the mercury-mercurous ion reaction. It is important to note that the electrical half cell is completely sealed, except for the ion conductive diaphragm, so that the electrolyte is isolated and there is no effect upon the half cell by motion or exterior chemicals. The potential of the half cell is determined by the chloride ions in the electrolyte, which defines the mercury-mercurous ion reaction. Even shaking the electrode does not change the concentration. Thus, the effect of motion of the electrode is nil; and, of course, motion of the electrolyte saline solution has no effect upon the electrical potential. The cellophane diaphragm is put into electrical contact with the skin of a patient as soon as the diaphragm touches the skin. Since the solution behind the diaphragm is an isotonic saline solution, there is no irritation to the skin. The cellophane diaphragm is itself non-toxic, thereby creating no problems.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cross-sectional view of an electrode embodying the present invention;
FIG. 2 is a cross-sectional view taken on Line 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view taken on Line 3--3 of FIG. 2;
FIG. 4 is a copy of a graph, showing a representative readout using the subject electrode; and
FIG. 5 is a copy of a graph, showing a representative readout using a prior art electrode.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and especially to FIG. 1, an electrode which is a specific embodiment of the instant invention is a mercury calomel half cell and is generally indicated by numeral 10. The electrode 10 generally includes a housing 12, a mercury calomel mixture 14 in the housing, a diaphragm 16 mounted on the housing, and an electrolyte 18 held in the housing 12 by the diaphragm 16 and contacting the mercury calomel mixture 14. A platinum lead wire 20 is connected to the mercury calomel mixture 14.
The housing 12 is made of lucite and has a circular top 22, with a cylindrical wall 24 formed integral with the outer periphery of the top. A sealing groove 26 is formed in the cylindrical wall 24 adjacent to the open end thereof. The cylindrical wall has a threaded filling aperture 28 on one side and an electrical port 30 opposite to the filling aperture 28. A screw plug 31 is positioned in the filling aperture 28 to seal closed the aperture.
A non-conductive tube 32 is positioned in port 30 and fixed therein. Tube 32 extends radially inward of the cylindrical wall 24 to be aligned with the filling aperture 28 so that the tube may be filled with electrolyte by use of a syringe to eliminate air bubbles. The mercury calomel mixture 14 is positioned in the tube adjacent to the cylindrical wall 24. In this instance, the mercury calomel mixture is 50% mercury and 50% mercurous chloride by weight, although it is readily apparent that other suitable and well-known proportions may be used for the mercury calomel mixture. The lead wire 20 has one end positioned in the mercury calomel mixture. The other end of wire 20 is connected to a conventional insulated copper wire 34 to provide an electrical conductor from the mercury calomel mixture exteriorally of the housing 12. A seal 36 is positioned in the tube and surrounds a portion of the wire 20, thereby preventing the mercury calomel mixture from flowing out of the housing through the tube. Glass wool 38 is packed loosely in the other end of the tube to prevent the mercury calomel mixture from leaving the tube through the other end; but the glass wool is sufficiently loose to allow the electrolyte to contact the mercury calomel mixture.
In this specific embodiment of the invention, the electrolyte 18 is an isotonic physiological saline solution of nine grams of sodium chloride per liter of water. The saline solution has free chloride ions for defining the mercury-mercurous ion reaction in the half cell. The saline solution does not completely fill the housing, but rather a small air pocket is provided. The small air pocket provides "give" to the diaphragm so that the diaphragm accommodates itself to a surface contact. The diaphragm 16 includes a sheet of cellophane 40 which covers the open end of the housing 12. The cellophane sheet 40 is held in place by a conventional rubber O-ring 42, which rests in the groove 26. The O-ring 42 is sufficiently tight so that the electrolyte does not leak between the wall 24 and the cellophane sheet 40.
The electrode 10 is connected to an appropriate amplifier and recording instrument in a well-known manner by means of an electrical conductor, i.e., the copper wire 34. The electrical apparatus is not shown herein since it is well-known in the art, but it may be a device such as a Hewlett-Packard 1511A electrocardiograph. The electrode 10 is placed on the skin of a patient and is held there by any appropriate means, such as, surgical adhesive tape.
A second and third electrode are also appropriately placed on a patient, as is well-known in the art. The second and third electrodes are also held in position by surgical adhesive tape. The second and third electrodes are also connected to the electrocardiogram machine. Additional electrodes may also be placed on the patient and appropriately connected to the machine, depending upon the particular application. The physiological electrical potential between two areas of the body is detected by the electrode and transmitted to the electrocardiogram machine. It is important to note that even though the electrode is secured to a patient and subjected to motion, this motion produces no effect on the electrode in view of the fact that the potential is determined solely by the chloride ion concentration in the electrolyte. It should further be noted that there is substantially no DC offset between electrode pairs. Freedom from DC offset and half cell stability facilitates measurements with a DC amplifier when desired. Since the electrode is held in contact with the patient's skin without the use of a paste or gel, as is conventional, there is no paste or gel to dry out, causing impedance changes and attendant deterioration of signal quality. Inasmuch as the electrode is held on a person's skin, the patient may perspire slightly under the electrode. This perspiration does not impede the operation of the electrode.
The electrode 10 without a paste or gel between the electrode and a patient gives the same results as a conventional electrode with paste, clearly showing that the electrode 10 eliminates all of the problems associated with a paste and provides the advantages mentioned above. Electrode 10 and two other identical electrodes were attached to a patient with surgical adhesive tape in the usual locations on a patient. The electrodes were connected to a 1511A electrocardiogram manufactured by Hewlett-Packard of Waltham, Massachusetts, in the configuration known as "Lead I", and the results were recorded. A copy of the results is shown at FIG. 4. Three Welsh electrodes manufactured by Bowen & Co., Inc., of Bethesda, Maryland, were attached to the same patient at the same locations. A conventional paste was applied to the patient in conjunction with the Welsh electrodes. The Welsh electrodes were connected in the same configuration, and a copy of the results is shown in FIG. 5. Comparison of the electrocardiograms clearly demonstrates that, for short-run readings, there is no difference between the use of a conventional electrode with paste and electrode 10 without any paste. The advantages of the electrode 10 are accentuated in a long-run observation.
Although a specific embodiment of the herein-disclosed invention has been shown and described in detail above, it is to be understood that one skilled in the art may make various and sundry modifications without departing from the spirit and scope of the present invention. The present invention is limited only by the appended claims. | An electrode is provided for medical and biological use. The electrode is a calomel type electrode having a housing, with a mercury-calomel saline solution junction in the housing. A cellophane diaphragm is mounted on the housing to retain the saline solution. However, the diaphragm is sufficiently permeable to allow ionic conduction between a surface of a body being tested and the saline solution. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. Ser. No. 12/723,983, filed Mar. 15, 2010.
TECHNICAL FIELD
[0002] The present invention relates to methods and compositions for controlling proppant flow through a wellbore, and more particularly relates, in one embodiment, to methods and compositions for controlling proppant flow through a wellbore after proppant fracturing.
BACKGROUND
[0003] There are a number of procedures and applications that involve the formation of a temporary seal or plug while other steps or processes are performed, where the seal or plug must be later removed. Often such seals or plugs are provided to temporarily block a flow pathway or inhibit the movement of fluids or other materials, such as flowable particulates, in a particular direction for a short period of time, when later movement or flow is desirable.
[0004] The recovery of hydrocarbons from subterranean formations often involves applications and/or procedures employing coatings or plugs. In instances where operations must be conducted at remote locations, namely deep within the earth, equipment and materials can only be manipulated at a distance. One such operation concerns perforating and/or well completion operations incorporating filter cakes and the like as temporary coatings.
[0005] Generally, perforating a well involves a special gun that shoots several relatively small holes in the casing. The holes are formed in the side of the casing opposite the producing zone. These perforations, or communication tunnels, pierce the casing or liner and the cement around the casing or liner. The perforations go through the casing and the cement and a short distance into the producing formation. Formations fluids, which include oil and gas, flow through these perforations and into the well.
[0006] The most common perforating gun uses shaped charges, similar to those used in armor-piercing shells. A high-speed, high-pressure jet penetrates the steel casing, the cement, and the formation next to the cement. Other perforating methods include bullet perforating, abrasive jetting, or high-pressure fluid jetting.
[0007] The characteristics and placement of the communication tunnels can have significant influence on the productivity of the well. Technology has been developed which eliminates the need for perforating guns and enables significantly more controlled perforation through the use of fluid conduits installed within casings. These fluid conduits may be extended out from the casing to contact a formation wall, thereby forming “perforations” at desired locations along the length of the casing. Temporary plugs in the conduits form fluid barriers, and the conduits are pushed out from the casing via fluid pressure. The plugs may be made of a porous filter structure on which a degradable barrier material is coated. After the fluid conduits are extended, the degradable material may be removed, thereby allowing the flow of fluids through the filter structure. This technology, known as TELEPERF™ from Baker Hughes Inc, is described in more detail in U.S. Pat. Nos. 7,527,103 and 7,461,699, each incorporated by reference herein its entirety.
[0008] In some instances, it may be necessary or desirable to fracture a formation to enable or promote the flow of fluids therethrough. For example, in low-permeability reservoirs, it may be beneficial to fracture the well formation and inject proppants into the fractures to stimulate the flow of fluids (such as oil, gas, water, and the like) through the formation. When hydraulic fracturing is performed, the viscous fracturing fluids mixed with proppant are flowed into the formation through the casing and associated perforations. However, filters in the above-described TELEPERF™ devices may obstruct or impede the high-viscosity fluids and proppants utilized in hydraulic fracturing from entering the formation.
[0009] Accordingly, hydraulic fracturing may be accomplished in TELEPERF™ devices by temporarily plugging the telescoping conduits to inhibit the flow of fluid therethrough. Hydraulic pressure telescopes the flow conduits outward, and the temporary plugs may then be removed from the flow conduits via an acidic solution. High-viscosity fluids and proppants may then be injected to fracture the subterranean reservoir. This technology, known as TELEFRAC™ from Baker Hughes Inc, is described in more detail in U.S. patent application Ser. No. 12/723,983, which is herein incorporated by reference its entirety.
[0010] Although the TELEFRAC™ method described above enables proppant fracturing through the TELEPERF™ tunnels, the system does not provide for a filter structure through which the formation fluids may be returned to the well surface. It may be desirable to filter the formation fluids in order to control proppant flow back into the wellbore. Ensuring that the proppant remains in the fracture will increase the fracture integrity in the near wellbore region and maintain higher productivity that results from well fracturing.
SUMMARY
[0011] There is provided, in one non-limiting form, a method for extracting well fluids from a fractured hydrocarbon formation while controlling the flow of proppant back through the wellbore. The hydrocarbon formation has disposed within it a pipe having orifices through at least a region of its wall, and telescoping flow conduits, pathways, channels, passages, outlets, or the like situated within the orifices in a retracted position within the pipe. The telescoping flow conduits contain porous objects disposed within them to control the flow of proppant and sand from the formation. The hydraulic fracturing method includes extending the telescoping flow conduits radially outward from the pipe in the direction of the wellbore wall via an extension fluid. Hydraulic fracturing fluid may then be injected into the subterranean reservoir via the pipe and the telescoping flow conduits. The porous objects are then injected into the telescoping flow conduits to control the flow of proppant and formation sand into the wellbore during production of the formation.
[0012] In another non-limiting embodiment of the present disclosure, a system or apparatus may be provided for use in well completions. The system may include a pipe, such as a conductor pipe, a casing, a tubing, a liner, or the like. Through the wall of the pipe are disposed telescoping flow conduits made of at least two sleeves. In one exemplary embodiment, the first sleeve is attached to the pipe wall, and the second sleeve is disposed within the first sleeve and is moveable relative to the first sleeve. The second sleeve may contain an acid-soluble plug which temporarily blocks, inhibits, or prevents flow through the sleeve. The inhibited flow enables the second sleeve to be moved relative to the first sleeve via hydraulic pressure. After the plug is dissolved using an acidic solution, a porous ball may be inserted into the second sleeve to serve as a filter or a sand control screen during production of the well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a cross-section schematic view of a wellbore having an oil well casing or tubing disposed therein which has a plurality of telescoping conduits therein, each in a retracted position in an orifice in the casing and having a dissolvable plug therein
[0014] FIG. 2 is a cross-section schematic view of the telescoping conduit of FIG. 1 ;
[0015] FIG. 3 is a cross-section schematic view of the oil well casing of FIG. 1 having a plurality of telescoping conduits therein, where the conduits have been extended or expanded in the direction of the wellbore wall;
[0016] FIG. 4 is a cross-section schematic view of the oil well casing of FIG. 1 having a plurality of telescoping conduits therein, where the plugs in the conduits have been removed and porous objects have been introduced into the casing and the conduits;
[0017] FIG. 5 is a cross-section schematic view of the oil well casing of FIG. 1 having a plurality of telescoping conduits therein, where the conduits have been fully extended and have the porous objects of FIG. 4 disposed therein;
[0018] FIG. 6 is a cross-section schematic view of the telescoping conduit of FIG. 1 in a fully extended position; and
[0019] FIG. 7 is a perspective view of a sleeve of the telescoping conduit of FIG. 1 having collet fingers with tabs.
DETAILED DESCRIPTION
[0020] In accordance with a present embodiment, an oil well casing or liner may contain pre-formed perforations, or holes, therethrough. Further, installed in each perforation may be a moveable fluid conduit or pathway which enables fluid communication between the interior and the exterior of the casing or liner. For example, the fluid conduit may be several generally cylindrical conduits arranged coaxially with a limited range of motion relative to each other along the commonly shared axis, e.g. in a telescoping configuration.
[0021] The flow conduits or pathways may further contain temporary plugs which inhibit or prevent the flow of fluid through the conduits. The moveable flow conduits or pathways may be telescoped out from the casing or liner into the wellbore annulus via fluid pressure within the casing or liner. That is, as fluid is pumped into the casing, the temporary plugs inhibit the fluid from exiting the casing via the flow conduits. Rather, as the pressure inside the casing increases, the flow conduits are pushed outward from the casing. Optimally, the flow conduits contact the wellbore wall, thereby forming a flow pathway through the annulus from the interior of the casing to the formation. In this manner, the described structure may be used as a completion tubular to avoid using a cementing and perforation process. After the assembly is in place across the producing zone location, the temporary plugs may be dissolved using an acidic solution.
[0022] A hydraulic fracturing fluid may then be pumped through the casing, out the flow conduits, and into the formation. The fluid may fracture the formation, thereby increasing its permeability and stimulating production. In addition, proppants may be used in the fluid to keep the fracture open after the procedure has been completed. In an exemplary embodiment, porous media may then be disposed within the flow conduits to inhibit return of the proppants during production of the formation.
[0023] The well completion system will now be described more specifically with respect to the figures, where in FIG. 1 there is shown a cross-section of a vertically oriented, cylindrical casing or liner 10 having a plurality of orifices 12 therethrough. The orifices 12 may be created by machining or other suitable technique. The casing 10 is placed in a borehole or wellbore 14 through a subterranean reservoir 16 . The subterranean reservoir 16 may be a flow source from which gas and/or oil is extracted or, alternatively, a flow target into which gas or water is injected. The wellbore 14 has a wall 18 coated with a filter cake 20 deposited by a drilling fluid or, more commonly, a drill-in fluid or completion fluid 22 . In some non-limiting embodiments, the filter cake 20 may be optional. The casing 10 and the wall 18 define an annulus 24 there between.
[0024] Flow conduits 26 such as that shown in FIG. 2 may be disposed within the orifices 12 . The flow conduits 26 are shown in FIG. 1 in a retracted position within the casing 10 . The flow conduit 26 may be a series of sleeves 28 - 31 open on opposing ends having an enveloping wall defining their shape. It should be understood that although the exemplary flow conduit 26 is made up of four sleeves 28 - 31 , any number of sleeves may be used in accordance with a present embodiment. In the exemplary embodiment, the sleeves 28 - 31 are generally cylindrical and have different internal radii 34 - 37 and external radii 38 - 41 . The sleeves 28 - 31 may be arranged concentrically with respect to one another along a common axis 44 such that the first sleeve 28 having internal radius 34 and external radius 38 is disposed within the second sleeve 29 having internal radius 35 and external radius 39 , which in turn is disposed within the third sleeve 30 having internal radius 36 and external radius 40 , which is further disposed within the fourth sleeve 31 having internal radius 37 and external radius 41 . Further, each sleeve 28 - 31 may be moveable with respect to the other sleeves 28 - 31 along the axis 44 .
[0025] The flow conduits 26 contain temporary plugs 46 made of a soluble substance having low permeability and high strength. For example, the plug 46 may be Indiana limestone having an acid solubility greater than 70% and permeability of less than 10 mD. Although the present disclosure refers to the soluble substance of the plugs 46 as limestone, it should be understood that other materials having similar solubility, permeability, and strength may be utilized in the disclosed methods and systems. In a non-limiting embodiment, the plug 46 may be pre-formed and secured within one or more of the sleeves 28 - 31 . For example, the plug 46 may be inserted into the sleeve 28 and abutted against the inside of a flange 48 . In other embodiments, the plug 46 may be force fit into one or more of the sleeves 28 - 31 or disposed at an end of one of the sleeves 28 - 31 via a threaded hollow cap.
[0026] Once the casing 10 is placed or positioned in the wellbore 14 , a fluid 50 may be pumped through the casing 10 and the conduits 26 , as shown in FIG. 3 . As noted above, the plugs 46 within the conduits 26 have a very low permeability; accordingly, flow of the fluid 50 through the plugs may be substantially or completely inhibited. As the fluid 50 is pumped into the casing 10 , enough hydraulic pressure is built up to extend the flow conduits 26 radially outward from the casing 10 into the annulus 22 , such that the flow conduits 26 may be in contact with the producing formation 16 . That is, the conduits 26 may be extended out from the casing 10 in a direction generally perpendicular to a longitudinal axis 52 of the casing 10 . The hydraulic pressure of the fluid 50 typically causes the conduits 26 to extend to a position in which the conduits 26 touch or nearly touch the wall 18 .
[0027] An acidic solution, such as dicarboxylic acid, may then be pumped into the casing 10 to dissolve the plugs 46 , thereby forming flow paths 54 through the annulus 22 between the casing 10 and the formation 16 , as shown in FIG. 3 . The acidic solution may also dissolve the portions of the filter cake 20 (if present) with which it comes into contact. Fracturing fluids containing proppants may then be flowed through the casing 10 at high pressure to fracture the formation 16 in accordance with techniques well known in the art. Because the limestone plugs 46 may be substantially removed and do not leave behind a porous substrate to act as a filter, the proppants, such as grains of sand or the like, are not hindered from flowing into the fractures (not shown) created in formation 16 .
[0028] In a non-limiting embodiment, the fluid 50 used to extend the conduits 26 may also be utilized to dissolve the plugs 46 . That is, the fluid 50 may be an acidic solution having a low enough chemical reaction rate with the limestone plugs 46 that the plugs 46 begin slowly dissolving while the hydraulic pressure of the extension fluid 50 pushes the conduits 26 outward toward the wellbore wall 18 . After the conduits 26 are extended out to touch the face of the reservoir 16 , the acidic fluid 50 may continue to be pumped into the casing 10 to substantially dissolve the plugs 46 . It should be understood that the method herein is considered successful if the plugs 46 dissolve sufficiently to open up the flow conduits 26 enough to enable flow of viscous fracturing fluids and proppants therethrough.
[0029] After the well is fractured, porous objects 56 may be introduced into the casing 10 and pumped into the fluid conduits 26 via a pressurized fluid flow, as illustrated in FIG. 4 . After the porous objects 56 are propagated throughout the casing 10 into the fluid conduits 26 , the well may be produced. For instance, hydrocarbons may flow through the fluid conduits 26 from the formation 16 into the casing 10 , through the fluid conduits 26 , and into the formation 16 .
[0030] In an exemplary embodiment, the porous objects 56 may be generally spherical balls having a diameter approximately equivalent to that of the inner diameter 34 of the sleeve 28 . The balls may be composed of numerous beads (not shown) joined together to form the porous objects 56 . That is, high-strength beads (i.e., stainless steel, alloy, ceramic, and the like) may be bonded together via, for example, sintering or gluing, to form the generally spherical porous balls 56 . The beads may, in one embodiment, be from about 10 mesh (2000 μm) to about 100 mesh (149 μm). Additionally, the beads may be a generally uniform size or may be a variety of sizes.
[0031] In a non-limiting embodiment, the porous objects 56 may be carried into the extended flow conduits 26 via a flush fluid 58 , such as, for example, brine, potassium chloride solution, non-crosslinked polymer fluid, diesel, foam, or the like. The flush fluid 58 may be pumped through the casing 10 and into the flow conduits 26 with sufficient force to push the porous objects 56 into the fluid conduits 26 . The porous objects 56 may be blocked from escaping the flow conduits 26 by the flanges 48 in the sleeves 28 .
[0032] As the flush fluid 58 continues to flow into the casing 10 of FIG. 4 , a high pressure differential may be generated within the casing 10 relative to the annulus 24 , thereby further extending the flow conduits 26 radially outward toward the formation 16 , as illustrated in FIG. 5 . When the sleeve 28 moves relative to the sleeve 29 , collets 60 on the sleeve 28 may be actuated by contact with a flange 62 on the sleeve 29 . As better illustrated in FIGS. 5 and 6 , tabs 64 on the collets 60 may abut the flange 62 . As the sleeve 28 moves radially outward from the casing 10 along the axis 44 relative to the sleeve 29 , an angled surface 66 on the flange 62 may come into contact with complimentarily angled surfaces 68 on the tabs 64 . With additional pressure inside the casing 10 , a sufficient force may be generated to push the sleeve 28 still farther out relative to the sleeve 29 . As the angled surface 66 of the flange 62 moves past the angled surface 68 of the tab 64 , the force exerted radially inward toward the axis 44 may be such that the collets 60 are bent inward. When the collets 60 bend inward, the porous objects 56 may become trapped within the sleeve 28 between the flange 48 and the collets 60 .
[0033] Further features of the sleeve 28 include one or more tabs 70 protruding radially outward from the exterior of the sleeve 28 . These tabs 70 cooperate with an internal surface 72 of a flange 74 protruding radially inward from the interior of the sleeve 29 . Abutment of the tabs 70 with the flange 72 limits movement of the sleeve 28 relative to the sleeve 29 .
[0034] In addition, concentric rings 76 protrude radially outward from the exterior of the sleeve 28 . These rings 76 may have a buttress-type profile wherein the leading edge of each ring 76 is beveled, for example, at about 30 degrees relative to the exterior of the sleeve 28 , and the trailing edge is generally perpendicular to the exterior of the sleeve 28 . When flow conduit 26 telescopes outward, the sleeve 28 moves along the axis 44 relative to the sleeve 29 , and the beveled edges of the rings 76 move past the internal surface 72 of the flange 74 . The perpendicular edge of the rings 76 then abuts an external surface 78 of the flange 74 , thereby blocking the sleeve 28 from moving the opposite direction along the axis 44 relative to the sleeve 29 .
[0035] The tabs 70 and rings 76 on the sleeve 28 cooperate with the flange 74 on the sleeve 29 to enable limited movement of the sleeve 28 relative to the sleeve 29 in only one direction along the axis 44 . That is, when the sleeve 28 is expanded outward from the sleeve 29 along the axis 44 , the flange 74 essentially locks the sleeve 28 in place by limiting movement in one direction via abutment with the tabs 70 and in the other direction via abutment with the trailing edge of the rings 76 . The sleeves 29 - 31 may include similar features to enable telescopic expansion and prevent collapse of the flow conduit 26 .
CONCLUSION
[0036] It will be evident that various modifications and changes may be made to the foregoing specification without departing from the broader spirit or scope of the invention as set forth in the appended claims. Accordingly, the specification is to be regarded in an illustrative rather than a restrictive sense. For example, specific materials, fluids, acidic solutions, and combinations thereof falling within the claimed parameters, but not specifically identified or tried in a particular composition, are anticipated to be within the scope of this invention. Additionally, various components and methods not specifically described herein may still be encompassed by the following claims.
[0037] The words “comprising” and “comprises” as used throughout the claims is to be interpreted as “including but not limited to”. The present invention may suitably comprise, consist of, or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. For example, in one non-limiting embodiment, a pipe used in well completions may consist of or alternatively consist essentially of an interior space, an outer surface, at least one flow conduit and a porous object disposed within the flow conduit, as described in the claims. | Porous objects, such as porous balls, may be employed within telescoping devices to control proppant flowback through a completed well during production. The telescoping devices may connect a reservoir face to a production liner without perforating. Acid-soluble plugs initially disposed within the telescoping devices may provide enough resistance to enable the telescoping devices to extend out from the production liner under hydraulic pressure. The plugs may then be dissolved in an acidic solution, which may also be used as the hydraulic extension fluid. After the plugs are substantially removed from the telescoping devices, the reservoir may be hydraulically fractured using standard fracturing processes. The porous balls may then be inserted into the telescoping devices to block proppant used in the fracturing process from flowing out of the reservoir with the production fluids. | 4 |
RELATED APPLICATIONS
[0001] This application claims benefit of U.S. provisional patent application, serial No. 60/239,403, filed Oct. 11, 2000, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to artificial lift for hydrocarbon wells. More particularly, the invention relates to gas operated pumps for use in a wellbore. More particularly still, the invention relates to a gas operated pump having a removable valve insertable in a housing with fluid pathways in the housing that operate in conjunction with the valve.
[0004] 2. Description of the Related Art
[0005] Oil and gas wells include a wellbore formed in the earth to access hydrocarbon-bearing formations. Typically, a borehole is initially formed and thereafter the borehole is lined with steel pipe, or casing in order to prevent cave in and facilitate the isolation of portions of the wellbore. To complete the well, at least one area of the wellbore casing is perforated to form a fluid path for the hydrocarbons to enter the wellbore. In some instances, natural formation pressure is adequate to bring production fluid to the surface for collection. More commonly however, some form of artificial lift is necessary to retrieve the fluid.
[0006] Artificial lift methods are numerous and include various pumping arrangements. One common pump is a gas operated pump, as shown in FIG. 1. FIG. 1 is a section view of a wellbore with a gas operated pump disposed therein. The pump 30 is located adjacent perforations in the wellbore 10 . The pump operates with pressured gas injected from a high pressure gas vessel 24 into a gas supply line 80 to a valve assembly 40 disposed in a body of the pump 30 . The valve assembly 40 consists of an injection control valve 70 for controlling the input of gas into a accumulation chamber 34 and a vent control valve 90 for controlling the venting of gas from the chamber 34 . Operational power is brought to the valve assembly 40 by input lines 75 , 77 . The pump 30 has a first one-way valve 36 at the lower end 38 of the chamber 34 . An aperture 37 at the lower end 38 of the chamber permits formation fluid to flow through open valve 36 to enter the chamber 34 . After the chamber 34 is filled with formation fluid, the vent control valve 90 closes and the injection control valve 70 opens. Gas from the gas supply line 80 is allowed to flow through the open injection control valve 70 into the chamber 34 . As gas enters the chamber 34 , gas pressure forces the formation fluid downward, thereby closing the first one-way valve 36 . As the gas pressure increases, formation fluid therebelow is urged into outlet 42 and opens a second one-way valve 47 . Fluid enters the valve 47 and travels along passageway 32 and into the tubing string 20 . After formation fluid is displaced from the chamber 34 , the injection control valve 70 is closed, thereby restricting the flow of gas from the high pressure gas vessel 24 .
[0007] Hydrostatic fluid pressure in the passageway 32 acts against second one-way valve 47 , thereby closing the valve 47 and preventing fluid from entering the chamber 34 . The vent control valve 90 is opened to allow gas in the chamber 34 to exit a vent line 100 into an annulus 22 formed between the casing 12 and the tubing string 20 . As the gas vents, the gas pressure decreases thereby reducing the force on the valve 36 . At a point when the formation fluid pressure is greater than the gas pressure in the chamber 34 the valve 36 opens thereby allowing formation fluid to once again fill the chamber 34 . In this manner, a pump cycle is completed. As the gas operated pump 30 continues to cycle, formation fluid gathers in the tubing string 20 and eventually reaches the surface of the well for collection.
[0008] U.S. Pat. No. 5,806,598 to Mohammad Amani, incorporated herein by reference in its entirety, discloses a method and apparatus for pumping fluids from a producing hydrocarbon formation utilizing a gas operated pump having a valve actuated by a hydraulically actuation mechanism. In one embodiment, a valve assembly is disposed at an end of coiled tubing and may be removed from the pump for replacement.
[0009] The conventional pumps illustrated in FIG. 1 and described in the '598 patent suffer from problems associated with size limitations in downhole pumps. These valve assemblies for a gas operated pump have an internal bypass passageway for injecting gas into the chamber. The internal bypass passageway must be a large enough diameter to facilitate a correct amount of gas flow into the chamber. These internal structures necessarily make the valve large and bulky. A bulky valve assembly is difficult to insert in a downhole pump because of space limitations in a wellbore and in a pump housing.
[0010] There is a need, therefore, for a gas operated pump having a valve assembly that is less bulky. There is a further need for a gas operated pump with a removable valve that does not include a bypass passageway.
SUMMARY OF THE INVENTION
[0011] The present invention generally provides a gas operated pump having a removable and insertable valve. In one aspect, the invention includes a pump housing having a fluid path for pressurized gas and a second fluid path for exhaust gas. The fluid paths are completed when the valve is inserted into a longitudinal bore formed in the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] So that the manner in which the above embodiments of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
[0013] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0014] [0014]FIG. 1 is a cross section view of a prior art gas operated pump assembly in a well.
[0015] [0015]FIG. 2 is a section view showing a housing having a first and second fluid paths formed therein.
[0016] [0016]FIG. 3 illustrates the removable valve assembly disposed on a coiled tubing string.
[0017] [0017]FIG. 4 is a section view showing the removable valve assembly disposed on coiled tubing and located in the bore of the housing.
[0018] [0018]FIG. 5 illustrates another embodiment of a removable valve assembly for a gas operated pump.
[0019] [0019]FIG. 6 illustrates the valve assembly of FIG. 5 in a housing with an alignment tool to install the valve in the housing.
[0020] [0020]FIG. 7 illustrates a removable valve assembly and a housing with an electrical connection means therebetween housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] [0021]FIG. 2 is a section view showing a housing 200 of a gas operated pump. In a preferred embodiment, the housing includes two longitudinal bores as well as a number of internally formed motive fluid paths to operate a valve and to direct gas through the pump. The housing 200 includes a first threaded portion 205 formed in an interior of an upper end for connection to a string of tubulars (not shown) and a second threaded portion 210 on the exterior of a lower end for connection to an accumulation chamber (not shown). The housing 200 includes a first longitudinal bore 215 therethrough having an internal threaded portion 220 at a lower end for connection to a diptube (not shown). In use, the bore 215 serves as a conduit for production fluid pumped towards the surface of the well. The housing also includes a second longitudinal bore 225 . An aperture 235 formed in a wall of the housing provides communication between the second longitudinal bore 225 and an exterior of the housing 200 . A third bore 230 provides communication between an injection port 250 in a wall of the second longitudinal bore 225 and a lower end of the housing 200 for injection of pressurized gas into the accumulation chamber (not shown).
[0022] The second longitudinal bore 225 further includes a first 240 and a second 245 profile formed in an interior of the bore 225 to receive a removable valve assembly (not shown) that is inserted in an upper end 255 of bore 225 . In the preferred embodiment, the profiles 240 , 245 are continuous grooves and are formed to permit mating formations of the valve assembly to mate therewith as will be more fully described herebelow.
[0023] [0023]FIG. 3 illustrates the removable valve assembly 300 disposed on the end of a coiled tubing string 325 . The removable valve assembly 300 includes an inlet control valve 305 , a vent control valve 310 , a valve stem 315 and an actuator 320 . The valve stem 315 is connected to both the inlet control valve 305 and the vent control valve 310 . The actuator 320 moves the valve stem 315 , alternatively opening and closing the inlet control valve 305 and the vent control valve 310 . When the inlet control valve 305 is in the open position, gas flows down a coiled tubing string 325 into the assembly 300 and out through a gas outlet port 330 . Alternatively, when the vent control valve 310 is in the open position, gas enters a vent inlet port 340 and exits a vent outlet port 335 . A first 345 and a second 350 control conduits are housed inside the coiled tubing string 325 . The first 345 and the second 350 control conduits are typically hydraulic control lines and are used to actuate the valve assembly 300 . Additionally, electric power can be transmitted through the one or more control conduits 345 , 350 to actuate the valve assembly 300 . Valve assembly 300 may include data transmitting means to transmit data such as pressure and temperature within the pump chamber through the one or more control conduits 345 , 350 to the surface of the wellbore. In these instances, the valve assembly 300 or the housing 200 may include sensors. Data transmitting means can include fiber optic cable.
[0024] A first 355 , second 360 , and third 365 seals are circumferentially mounted around an external surface of a valve assembly 300 . The purpose of the seals is to isolate fluid paths between the valve assembly 300 and the housing (FIG. 2) when the valve assembly 300 is inserted therein. The assembly 300 further includes a first 370 and a second 375 key to secure the valve assembly 300 axially within the housing. The first 370 and the second 375 keys are outwardly biased and are designed to mate with the profiles in the interior surface of the housing (FIG. 2).
[0025] [0025]FIG. 4 is a section view of the valve assembly 300 disposed in the housing 200 . In the embodiment of FIG. 4, the valve assembly 300 is shown at the end of the string of coiled tubing 325 that provides a source of pressurized gas to operate the pump. An accumulator chamber 415 for collecting formation fluid is secured to the housing 200 by the second threaded portion 210 at the lower end. A tubing string 405 is secured to the housing 200 at the first threaded portion 205 . A diptube 410 is secured to the housing 200 at internal threaded portion 220 of the first longitudinal bore 215 . A vent line 420 is secured to the housing 200 at the aperture 235 to provide a passageway for gas venting from the chamber 415 .
[0026] In operation, the removable valve assembly 300 is installed at an end of the coiled tubing string 325 and the string 325 is inserted in tubing string 405 at the top of the wellbore. As the valve assembly 300 reaches the housing 200 , a profile means and guide orient and align the valve assembly 300 with the second longitudinal bore 225 which is offset from the center of the housing 200 . Profile means and guides are well known in the art and typically include some mechanical means for orienting a device in a wellbore. After insertion into the upper end 255 of the bore 225 , the valve assembly 300 is urged downwards until the first 370 and the second 375 keys of the valve assembly 300 are secured in place in the first 240 and the second 245 profiles of the housing 200 . Mating angles on the keys and profiles permit the retention of the valve in the housing 200 . The first seal 355 and the second seal 360 form a barrier on the top and bottom of the injection port 250 to prevent leakage of injected gas into the accumulator chamber 415 . The second seal 360 and the third seal 365 provide a barrier on the top and bottom of the aperture 235 to prevent leakage of gas exiting the vent line 420 .
[0027] [0027]FIG. 5 is a section view of an alternative embodiment of a valve assembly 500 and FIG. 6 is a section view of the valve assembly 500 installed in a housing 600 . The housing 600 of FIG. 6 includes additional fluid paths formed therein. Hydraulic conduits 630 , 635 are formed in the housing 600 and serve to carry hydraulic power fluid from an upper end of the housing 600 to the longitudinal bore 645 formed in the housing 600 . The lines intersect the bore 645 at a location ensuring they will communicate with the valve assembly 500 after it has been installed in the bore 645 and is retained therein with the retension means described with respect to FIG. 4. Also formed in the housing 600 is an internal gas line 640 providing communication between the upper end of the housing 600 and the bore 645 .
[0028] By providing hydraulic conduits 630 , 635 and gas line 640 internally within the housing 600 , there is no need for separate hydraulic lines or a gas supply line to remain attached at an upper end of the valve assembly 500 . As illustrated in FIG. 6, the valve assembly 500 is installed in bore 645 with a selective connector or gripping tool 607 that temporarily retains the valve assembly 500 by gripping a fish neck 580 formed at the upper end of the valve assembly 500 . Gripping tools typically operate mechanically with inwardly movable fingers. A kickover tool can be utilized to align the valve assembly 500 with the offset bore 645 . Kickover tools and gripping tools are well known in the art. Because no rigid conduits are needed between the surface of the well and the upper end of the valve assembly 500 , the assembly 500 can be inserted and removed from the housing using wireline or even slick line.
[0029] [0029]FIG. 7 is a section view of a removable valve assembly 700 in a pump housing 705 with an electrical connection therebetween. For clarity, the assembly 700 is illustrated partially inserted in the housing 705 . In the embodiment of FIG. 7, the housing 705 is electrically wired with conductors 710 , 715 that lead to a lower portion of the longitudinal bore 720 . A contact seat 725 is located within the bore 720 and is constructed and arranged to receive an electrode 730 protruding from a lower end of the valve assembly 700 . As the assembly 700 is inserted into the bore 720 and is axially located therein, the electrode 730 is seated in the contact seat 725 and an electrical connection between the housing 705 and the valve assembly 700 is made. Thereafter, the valve assembly 700 may be actuated electrically through the use of a solenoid switch 735 disposed within the valve assembly 700 . As with the other embodiments of the invention, the housing includes flow paths formed therein that communicate with the valve assembly 700 and reduce the necessary bulk of the valve assembly 700 .
[0030] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | The present invention generally provides a gas operated pump having a removable and insertable valve. In one aspect, the invention includes a pump housing having a fluid path for pressurized gas and a second fluid path for exhaust gas. The fluid paths are completed when the valve is inserted into a longitudinal bore formed in the housing. | 4 |
LATIN NAME
[0001] ‘ Vaccinium Hybrid’
VARIETAL DENOMINATION
[0002] ‘EB 8-46’
RELATED APPLICATION DATE
[0003] The present application claims priority to Australia Plant Breeders Rights Application, Serial No. 2012/260 and which was filed on Nov. 29, 2012.
BACKGROUND OF THE NEW VARIETY
[0004] The present invention relates to a new, novel, and distinct variety of blueberry plant ‘ Vaccinium Hybrid ,’ and which has been denominated varietally as ‘EB 8-46’, hereinafter.
ORIGIN AND ASEXUAL REPRODUCTION OF THE NEW VARIETY
[0005] The present variety of blueberry plant resulted from an ongoing development program of plant breeding. The purpose of this program is to improve the commercial quality of various plant varieties by creating and releasing promising selections of plants including blueberries. To this end, I have made both controlled and hybrid cross-pollinations each year in order to produce resulting plant populations from which improved progenies are evaluated and selected.
[0006] The blueberry plant ‘EB 8-46’ was derived from a controlled cross-pollination employing the blueberry plant ‘BB-5’ [unpatented], and the pollen parent was ‘SB-1’ [also unpatented] during the 2005 growing season and which took place at Yanchep Springs, Yanchep, Western Australia. The seed parent ‘BB-5’ is characterized by an semi-spreading growth habit, an early season of flowering, and which further produces medium-sized fruit. The pollen parent ‘SB-1’ on the other hand, is characterized by a spreading growth habit, an early season of flowering, and which produces relatively large sized fruit. Seed from the seed parent, and which was derived following the aforementioned cross-pollination, produced about 500 plants. These plants were then grown, and the first fruit was evaluated during the 2007 growing season. Further, an additional assessment of these same plants took place in 2008. The new variety, ‘EB 8-46’ was then selected at that time for further asexual reproduction and evaluation. The present variety was asexually reproduced by cuttings, and the plants produced from this first asexual propagation were evaluated during the 2009 through 2013 growing seasons. The asexually reproduced plants were true to the original plant, and it was concluded at that time that ‘EB 8-46’ was a new, novel and distinct variety of blueberry plant.
[0007] In relative comparison to the closest known variety, that being the ‘Sharpeblue’ blueberry plant [unpatented], the present variety produces early maturing, very large fruit. The new variety of blueberry plant further has an intermediate growth habit, and additionally produces oblate shaped fruit. In contrast, the ‘Sharpeblue’ blueberry plant produces fruit which are mature for harvesting and shipment from a date which is considered early to approximately middle of the growing season. Moreover, the ‘Sharpeblue’ blueberry plant produces fruit which have an average to medium size, and also has an intermediate growth habit. It should be noted that the new variety is distinguishable from its parents, and that of the ‘Sharpeblue’ blueberry plant by producing extra large sized fruit, having a dry, small, picking scar, very good fruit flavor and early flowering and fruit production dates.
BRIEF DESCRIPTION OF THE DRAWING
[0008] The accompanying drawings, which are provided are color photographs of the new blueberry plant.
[0009] FIG. 1 depicts several mature fruit of the new variety and which is sufficiently matured for harvesting and shipment. Further, FIG. 1 additionally depicts a typical shoot bearing leaves and several separate leaves showing the dorsal and ventral coloration thereof, as well as the growth habit of the new plant.
[0010] FIG. 2 depicts a twig bearing typical leaves, and several fruit of the new variety.
[0011] FIG. 3 depicts the growth habit of the new plant.
[0012] The colors in these photographs are as nearly true as is reasonably possible in a color representation of this type. Due to chemical development, processing and printing, the leaves and fruit depicted in these photographs may or may not be accurate when compared to the actual specimen. For this reason, future color references should be made to the descriptions as provided hereinafter.
NOT A COMMERCIAL WARRANTY
[0013] The following detailed description has been prepared to solely comply with the provisions of 35 U.S.C. §112, and does not constitute a commercial warranty (either expressed or implied) that the present variety will, in the future, display the botanical, horticultural, or other characteristics as set forth, hereinafter. Therefore, this disclosure may not be relied upon to support any future legal claims including, but not limited to, breach of warranty of merchantability, or fitness for any particular purpose, or non-infringement, which is directed, in whole, or in part, to the present new variety.
DETAILED DESCRIPTION
[0014] Referring more specifically to the botanical details of this new and distinct variety of blueberry plant, the following has been observed during the sixth fruiting season under the ecological conditions prevailing at the farm of the inventor, and which is located near Yanchep Springs, Western Australia.
Plant:
Plant vigor .—The present variety of blueberry is considered to be average to strong with regard to plant vigor. This is similar to the closest known variety, that being the ‘Sharpeblue’ blueberry plant [unpatented]. Plant growth habit .—Considered intermediate to strong in relative comparison other known varieties. This is similar to the growth habit as exhibited by the ‘Sharpeblue’ blueberry plant when grown under similar conditions. Color .—One Year Old Shoots — Green. This color is not distinctive of the new variety and is similar to the color as expressed by the ‘Sharpeblue’ blueberry plants when grown under similar conditions. Internode length .—One Year Old Shoots — Considered medium for the species. This is in contrast to the same characteristic as expressed by the ‘Sharpeblue’ blueberry plant which exhibits a medium to medium-long internode length.
Leaf:
Leaf length .—Generally — Considered medium for the species. This characteristic is in contrast to the growth characteristic as expressed by the ‘Sharpeblue’ blueberry plant which expresses a medium to long length. Leaf ratio .—Length/Width — Considered medium for the species. This is in contrast to the growth characteristic as expressed by the Sharpeblue blueberry plant which is considered medium to broad. Leaf shape .—Generally — Considered ovate. This trait is similar to the growth characteristic as expressed by the ‘Sharpeblue’ blueberry plant when grown under similar conditions. Leaf color .—Dorsal Surface — Green. This color is not distinctive of the variety and is similar to the color as expressed by the ‘Sharpeblue’ blueberry plant when grown under similar conditions. Color intensity .—Dorsal Surface — The green color intensity as expressed in the leaves of the present variety appear noticeably darker (medium to dark) in relative comparison to the green color of the leaves as expressed by the growth habit of the ‘Sharpeblue’ blueberry plant. This is a distinguishing characteristic of the present variety. Leaf margin .—Generally — The leaf margin of the present variety is considered entire. This same growth characteristic is expressed by the ‘Sharpeblue’ blueberry plant.
Flower:
Flowers .—Generally — Time of vegetative bud burst considered early for the species, this is similar to the trait as expressed by the ‘Sharpeblue’ blueberry plant. Time of flowering .—One Year Old Shoots — Considered early. This is similar to the trait as expressed by the ‘Sharpeblue’ blueberry plant. Timing of flowering on current year's shoots .—Considered early for the species. Time of beginning of ripening on one year old shoots .—Considered early for the species. This is in contrast to the trait as expressed by the closest known variety where the ripening is considered early to medium for the species. Time of beginning of ripening on current year shoots .—Considered early. This is in contrast to the early to medium date as expressed by the ‘Sharpeblue’ blueberry plant. Flower bud .—Anthocyanin coloration — Considered very weak for the species. A similar characteristic is expressed by the ‘Sharpeblue’ blueberry plant when grown under similar ecological conditions. Inflorescence length .—Considered medium for the species. This characteristic is not distinctive of the variety. Corolla shape .—Considered urceolate. This is similar to the characteristic as expressed by the ‘Sharpeblue’ blueberry plant. Flower size .—Corolla Tubes — Considered medium for the species. This is in contrast to the growth characteristic as expressed by the ‘Sharpeblue’ blueberry plant when grown under similar conditions and where the Corolla tubes are medium to large. Corolla tube coloration .—Anthocyanin — Considered weak to very weak. This is in contrast to the growth characteristic as expressed by the ‘Sharpeblue’ blueberry plant which appears merely weak. Corolla tube .—Ridges — Present. This growth characteristic is also expressed by the ‘Sharpeblue’ blueberry plant when grown under similar conditions.
Fruit:
Fruit cluster density .—Considered medium to dense for the species. This fruit cluster density is dissimilar to the growth characteristic as expressed by the ‘Sharpeblue’ blueberry plant when grown under similar conditions and where the fruit cluster density is considered dense to very dense. Unripe fruit .—Color — The green coloration as expressed by the unripe fruit of the present variety is considered medium in intensity. This is in contrast to the fruit color as seen on unripe fruit of the ‘Sharpeblue’ blueberry plant when grown under similar conditions. In that case, the unripe fruit have a light to medium green color. Fruit size .—Generally — The present variety produces very large fruit in contrast to the medium sized fruit as produced by the closest known variety, that being the ‘Sharpeblue’ blueberry plant. Fruit shape .—Longitudinal Sectional View — Considered oblate. This is similar to the shape of the fruit which are produced by the ‘Sharpeblue’ blueberry plant. Sepal position/altitude .—Considered semi-erect in contrast to the orientation and attitude of the sepals when seen on the ‘Sharpeblue’ blueberry plant when grown under similar conditions. Sepal type .—The present variety has an incurring shaped sepal as compared to the straight type of sepal as expressed in the growth habit of the ‘Sharpeblue’ blueberry plants when grown under similar ecological conditions. Fruit diameter .—Calyx Basin — Medium for the species. This is in contrast to the growth habit as expressed by the ‘Sharpeblue’ blueberry plant when grown under similar conditions, and where the diameter of the Calyx basin is considered small to medium. Calyx basin/depth .—Considered shallow to medium in depth. This is in contrast to the growth habit as expressed by the ‘Sharpeblue’ blueberry plant and when grown under similar conditions and where this depth is considered merely medium. Intensity of fruit bloom .—Considered very strong for the variety. This is in contrast to the strong bloom intensity of the ‘Sharpeblue’ blueberry plant when grown under similar ecological conditions. Fruit skin color .—Considered very dark blue and similar to the coloration as seen on the fruit of the ‘Sharpeblue’ blueberry plant when grown under similar conditions. Fruit firmness .—Generally — The present variety produces very firm fruit in contrast to the medium firmness fruit as produced by the ‘Sharpeblue’ blueberry plant when grown under similar conditions. Fruit sweetness .—Generally — The present variety produces fruit having a high degree of sweetness in contrast to the average sweetness as expressed by the fruit produced by the Sharpeblue Blueberry Plant when grown under similar conditions. Fruit acidity .—Generally — Considered low for the species. The low acidity, as expressed by the fruit grown by the present variety, is in contrast to the somewhat average or medium acidity as expressed by the fruit of the ‘Sharpeblue’ blueberry plant when grown under similar conditions. Plant .—Fruiting Type — Fruit appears on one year old and current season shoots. This is similar to the growth habit as expressed by the ‘Sharpeblue’ blueberry plant when grown under similar conditions. Date of ripening of fruit on current year's shoots .—Considered early for the species and earlier in time relative to the same growth habit as expressed by the ‘Sharpeblue’ blueberry plant when grown under similar conditions. The beginning of fruit ripening on one year old shoots is considered early for the species and in contrast to the later date as expressed by the growth habit of the ‘Sharpeblue’ blueberry plant. Resistance to insects and disease .—No particular susceptibilities were noted. The present variety has not been tested to expose or detect any susceptibilities or resistances to any known plant and/or fruit diseases. Although the new variety of blueberry plant possesses the described characteristics when grown under the ecological conditions prevailing near Yanchep Springs, Western Australia, it should be understood that the variations of the usual magnitude and characteristics incident to changes in growing conditions, fertilization, pruning, pest control, frost, climatic variables and horticultural management are to be expected. | A new and distinct variety of blueberry plant, which is denominated varietally as ‘EB 8-46’ is described, and which produces extra large sized fruit, and which further has a dry small picking scar, very good fruit flavor and an earlier flowering and fruit production dates when grown under the ecological conditions prevailing in Yanchep Springs, Western Australia. | 0 |
BACKGROUND OF THE INVENTION
This invention concerns fluid-bed combustion reactors and a method for the operation of a fluid-bed combustion reactor. The invention further concerns a fluid-bed cooler for particulate material.
Fluid-bed systems are used in a number of processes, wherein a good contact between solid particulate material and gas is desired. Examples are heat exchange, reactions with heterogeneous catalysts and reactions directly between solid matter and gases. The fluid-bed principle may briefly be explained in that the solid particulates are affected by a fluidization gas introduced from below, it being within certain constraints possible hereby to suspend the particles within a body of particulate materials and keep them suspended, even though the gas flow velocity does not need to rise to a level where single particles except for the very smallest ones would be entrained and carried away by the gas flow. Under such conditions the individual particles are freely movable, but the body of the particulate material will exhibit an upper surface, i.e. it behaves like a liquid from which the name fluid-bed. Hereby, obviously a very large area of contact between the solid particulates and the applied gas is achieved.
Recently fluid-bed systems have acquired a special interest in connection with applications related to combustion systems for solid fuels. Important advantages are that fluid bed systems may operate on various types of fuel and that an extremely good heat transfer from the combustion may be obtained. The body of particles within such systems may comprise inert particles such as sand, into which a minor proportion of fuel is added. The inert particles are heated by the combustion and circulate within the fluid-bed contacting suitable heat exchanger surfaces to transfer heat hereto. Heat transfer by radiation or by gas convection to fixed heat exchanger surfaces which is usual with other combustion systems will thus to some extent be replaced by heat transfer through physical transport of particles, whereby extended contact areas and heat exchange by direct contact between solid matter is obtained, whereby the heat exchange coefficient (number of watts exchanged related to m 2 's of surface area and related to degrees of temperature difference) is higher than that achieved by the contact between gas and fixed surface.
Fluid-bed combustion systems allow a closer control of combustion parameters and make it possible to clean the exhaust gas for certain undesirable materials as reactants may simply be intermixed into the bed material, making it possible to achieve a combustion which in several respects is more environmentally acceptable than it is possible with other combustion systems. However, besides these advantages there are also certain difficulties connected to fluid-bed reactors, among which may be noted that they are substantially more complicated than other combustion systems by requiring the controlled introduction of fluidization gas, and by requiring extended start-up periods, e.g. of the magnitude of 3 to 10 hours, due to the substantial amount of solid material to be heated. Furthermore, it is difficult to operate them completely satisfactory by partial load, and adjustments of the load can only be carried out slowly.
Fluid-bed combustion systems are traditionally classified by the mean velocity of fluidization gas upwards through the fluid-bed, several variants occurring operating at various gas velocities within a range that may be generally described by the limits designated slow beds and fast beds, respectively.
Slow beds are characterized by a fluidization velocity typically within the range 1 through 3 m/second, this velocity having lower limits defined by the requirement for oxygen to the combustion and by the requirement for a minimum gas velocity in order to fluidize the particles. The density within the body of particles will be relatively high and the bed must be relatively shallow in order to keep the gas pressure necessary for fluidization within reasonable limits. However, hereby the dwell time for fuel particles and for the gas within the bed becomes too short to ensure a complete combustion, slow beds therefore exhibiting not quite satisfactory combustion efficiency and little possibility for cleaning of the exhaust gas.
Fast beds are characterized by a fluidization velocity within the range of approximately 3 through 12 m/second, whereby a substantial portion of bed particles are entrained by elutriation with the fluidization gas and must be recirculated back to the bed. They are also designated circulating beds and do not exhibit any well-defined bed surface. They may provide a superior combustion and superior exhaust gas cleaning than slow beds, but have the disadvantage of requiring extended systems to separate bed particles from the exhaust gas and recirculate the particles. Another disadvantage related to fast beds is that the heat exchange coefficient between said particles and heat transfer surfaces is inferior at the higher velocities as compared to the velocities typical in the slow beds.
In the past several attempts have been made to devise designs obtaining the consolidated advantages of the slow beds and of the fast beds.
U.S. Pat. No. 4,111,158 to Reh et al. e.g. discloses a fluid-bed reactor with a fast bed, in which combustion takes place, a cyclone to separate the bed particles from the exhaust gas and a fluid-bed cooler, wherein the separated particles are passed through a secondary fluid-bed of the slow type, wherein the particles exchange and dissipate their heat to heat transfer surfaces. The system described is very complicated and extensive, which is considered extremely undesirable, keeping in mind that all conducts and transportation systems must be designed to withstand combustion at temperatures of the magnitude of 800° C.
U.S. Pat. No. 4,788,919 to Holm et al. discloses a more compact solution comprising a central combustion bed with gas inlets at the bottom and optionally with secondary gas inlets located hereabove, from which particles are elutriated and carried up into a top chamber, and with a secondary fluid-bed or a fluid-bed cooler arranged annularly around the central fluid-bed at a level above the central fluid bed so that the particles transported up into the top chamber may drop down into this secondary fluid-bed. In the secondary annular fluid bed, which is a slow bed, particles may dissipate their heat to heat transfer surfaces and the particles may thereafter by means of gravity flow back to return to the central primary fluid bed.
U.S. Pat. No. 4,594,967 to Wolowodiuk discloses a fluid-bed combustion reactor with a primary bed, a top chamber and a fluid-bed particle cooler arranged in such a way that particles entrained with the gas flow from the primary bed may enter the top chamber and drop down to the particulate cooler, wherein the particles pass serpentine tubes and are cooled. From the cooler the particles pass a valve means down to a storage chamber and from the bottom of the storage chamber the particles may pass another valve means to return to the primary fluid-bed. This design is relatively compact, but no possibility is disclosed for varying the relation between the various areas of cooling sections apart from a possibility for partly emptying the particle cooler by conveying particles down into the storage chamber so that a portion of the cooling tubes in the particle cooler will no longer be covered by particles. However, a such method of operation must be considered extremely disadvantageous as the particles serve the purpose of protecting the tubes against the corrosive effects of the exhaust gases and as any portion of tube situated just above the upper surface of the fluidized particles will be subjected to abrasive wear by particles thrown upwards from the fluid bed and hitting the tube with some velocity. The document includes no disclosure regarding the design of the valves for the flow of particles, mentioning only that they may be activated selectively. Thus, no facility for the continuous control or facility for obtaining a constant controlled flow of particles downwards through the particle cooler and returning to the reactor is shown.
The provision of a separate fluid-bed particle cooler is a considerable improvement to fluid bed combustion systems, however, substantial problems remain, which have as yet not been solved quite satisfactorily. The heat transfer systems briefly mentioned in the above patents will e.g. for power generator purposes normally comprise a water preheater, also designated an economizer, an evaporator, in which the water is evaporated, and a super-heater, in which steam is super-heated. These heat transfer systems operate at different temperatures and must therefore be arranged paying regard to heat energy transfer requirements and applicable temperatures. Another factor that must also be taken into account is that the heat transfer systems also serve the purpose of protecting the constructional elements against the elevated temperatures. In practical fluid-bed combustion systems the greater part of the walls must therefore be provided with heat transfer systems. The economizer, which operates at a relatively low temperature, is preferably arranged in the exhaust gas duct after other heat exchangers. The super-heater operating at the highest temperature, e.g. 500° to 530° C., is conveniently arranged with a greater portion within the fluid bed, where the good heat transfer coefficient for the particles and the heat transfer surfaces make possible the heating to the high temperatures and with a smaller portion in the exhaust gas duct. It is noted that by the greater and smaller portion is understood portions with greater and smaller heat power transfer rather than geometrically greater and smaller portions. Within the fluid-bed particle cooler the super-heater may also to some extent be protected against corrosion and erosion, which is a critical factor at the elevated temperatures.
Evaporator tubes are conveniently utilized for cooling the walls, but since typically the area of evaporator surfaces needed exceeds what can be integrated into the walls, further sections of evaporator tubes are arranged within the fluid-bed cooler or in the exhaust gas duct before the economizer, or sections of evaporator tubes may be arranged in all of these places. The areas of the various heat transfer surfaces are naturally fixed once the reactor has been built.
However, the optimal relation between the areas of the various heat transfer surfaces depend upon the type of fuel used. E.g. fuels developing a relatively large proportion of water or steam in the exhaust gas ideally need a relatively smaller evaporator surface area than it is the case by combustion of coal. Fuels developing a larger proportion of water or steam could e.g. be fuels actually containing water such as particles of coal suspended in water or fuels which due to a content of hydrogen develop water by the combustion such as is the case with straw or wood. In case a plant designed for the optimal combustion of coal is to burn straw, the water-flow through the heat transfer surfaces must be reduced, but hereby the temperature in the evaporator sections may rise unacceptably. Similar problems may arise by partial load. To operate at partial load the air flow is reduced while the temperature within the reactor is kept substantially unchanged. The heat radiated onto the reactor walls which is ultimately transferred into the evaporator tubes arranged within the walls is therefore not reduced very much and the temperatures within the evaporator tubes may therefore tend to increase by the reduced water flow. The opposite problem might however, depending upon the particular circumstances, also occur, i.e. the temperature of the super-heater tubes could increase too much by a load reduction, in particular in case the heat transfer surfaces are arranged partly in the exhaust gas duct and partly within the fluid-bed cooler. By partial loads the gas-flow for fluidization is reduced, but hereby the heat transfer from the exhaust gases drops much more than the heat transfer within the fluid-bed. As mentioned above the super-heater surfaces are often arranged for the greater portion within the fluid-bed, and in case a substantial portion of the evaporator surfaces is arranged in the exhaust gas flow the super-heater temperature may rise too much due to the reduction of the water-flow. It is here noted that the temperature within the fluid-bed and therefore within the combustion chamber should be kept within a narrow range for satisfactory operation of the fluid-beds at full load as well as at partial loads. The strategy practically adhered to in the prior art is the adding of water at suitable points between sections of the evaporator tubes and before the super-heater in order to ensure that the tube temperature is kept within safe limits, which, however, does not provide the best economy of the system.
A further reason for inferior efficiency by systems of the prior art operating at partial load is that the amount of particulate matter in the reactor may not be optimal. By partial load the fluidization velocity will be reduced and the density of the bed will therefore be increased. In order to obtain a predetermined level of the beds the amount of particulate matter must therefore also be altered.
BRIEF SUMMARY OF THE INVENTION
The object of the invention is to solve the above drawbacks of the fluid-bed reactors of the prior art.
A further object of the invention is to provide a fluid-bed combustion reactor operating with better energy efficiency than comparable reactors of the prior art.
A still further object of the invention is to provide a fluid-bed combustion reactor capable of operating efficiently over a wider load range than possible with comparable reactors of the prior art.
These objects are achieved by the fluid-bed cooler and a method of operating a fluid-bed combustion reactor as described below.
The sectionalization according to the invention is in essence defined by the sections or regions within the particle cooler vessel, within which fluidization gas is introduced. The various sections of the fluid-bed cooler do not need to be divided by physical partition walls. In the case the sections are not delimited by physical partition walls, boundary regions may exist which cannot clearly be referred to one of the sections. However, still the various sections may be operated in modes which are individually controllable, notwithstanding the fact that the boundaries may not be sharply defined.
The invention utilizes the discovery that the heat transfer may advantageously be controlled by the control of the fluidization gas velocity. The heat transfer coefficient for contact between the fluidized particles and the heat transfer surfaces depends upon the fluidization gas velocity in a way which may be explained in that this coefficient rises from a certain initial value by zero fluidization and climbs to a maximum at a given velocity of fluidization, which velocity sometimes is referred to as the optimal fluidization velocity, whereafter the coefficient slowly declines by further increase of the fluidization gas velocity.
The heat-transfer tubes are according to the invention divided into sections corresponding to the sections of fluidization. It is advantageous to operate every one of the tube sections at a substantially uniform load over each length of tube, and in particular to avoid temperature steps along the length of a tube. By using the sectionalization in such way that the super-heater is arranged within one section and the evaporator within another section the amount of heat transferred may be controlled individually for each of these sections by control of the fluidization gas velocity, whereby optimal conditions for the heat transfer may be achieved in all operating modes including operating at partial loads and operating with various types of fuel.
The flow of fluidization gas should, though, always be kept above a limit defined by the onset of fluidization. The fluidization induces a continuous agitation and mixing of the particles within the cooler, so that the particle discharge opening may be arranged practically anywhere in the cooler bottom wall.
A preferred embodiment of the invention provides, though, for the arrangement of at least one particle discharge opening within each section and for particle discharge flow control means associated with each of said openings.
According to a further preferred embodiment the sections are divided by a boundary region, which is not fluidized.
This provides for a physical separation between the sections by creating a "wall" of non-fluidized particle material so as to minimize or completely avoid intermixing between the sections, whereby the heat transfer within each section may be controlled substantially independently of the operating mode in the adjacent section. E.g. the heat transfer within one section may be reduced substantially by reducing the fluidization gas velocity within this section to the minimum, where the gas is just capable to fluidize the particles. During normal operation heated particle material will drop all over the fluid-bed cooler and the level of the particles in this section will build up until the "wall" will start to slide slowly and uniformly sideways towards the adjacent section, in which the level of particles is lower, so that the particles transferred from the first section will transfer heat to the tubes arranged therein. It is understood that substantially different modes of operation may be selected by simple control of valves, e.g. a first mode of operation, where the particles dropped onto the cooler move uniformly, i.e. parallel down over two sections of the cooler, a second mode of operation, where a portion of the particles moves serially from a first section to a second section and a third mode of operation, where a portion of the particles moves serially from a second section to a first section.
According to another preferred embodiment of the invention the fluid-bed cooler is divided into three sections, wherein a first-section accomodates evaporator tubes, a second section accomodates super-heater tubes and a third section provides storage for particles, but no cooling surfaces. Hereby a very simple storage facility for portions of the particles is provided so that the amount of particles actively used within the fluid-bed reactor may be adjusted providing an added facility for optimizing the amount of particles for the prevailing conditions of operation. Furthermore, it becomes possible to recirculate particles through the storage section and back to the primary fluid-bed without cooling, which is advantageous during start-up in order to achieve the operating temperature within the particles as quickly as possible and also advantageous in the cases where the amount of particles necessary for the combustion exceeds the amount of particles desired passed along the heat transfer surfaces.
The invention further provides a method for the operation of a fluid-bed reactor equivalent to the operation of the reactor described above, which method is defined in patent claim 16. By this method advantages equivalent to what is described above are achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features and advantages of the invention will appear from the following description of preferred embodiments with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic vertical cross sectional view through a fluid-bed reactor according to the invention,
FIG. 2 shows a horizontal cross-sectional view taken along the line II--II of FIG. 1,
FIG. 3 is a view similar to FIG. 1 showing another preferred embodiment of the invention;
FIG. 4 is a horizontal cross-sectional view taken along the line IV--IV of FIG. 3;
FIG. 5 is a vertical and partially schematic cross-sectional view of a cooler for particles according to another preferred embodiment of the invention; and
FIG. 6 is a view similar to FIG. 5, but showing af modified embodiment of a further the cooler for particles according to the invention.
DETAILED DESCRIPTION
Throughout the drawings equivalent or similar features are indicated by the same reference numerals.
Reference is first made to FIG. 1, showing a reactor 1 comprising a bottom chamber 2 surrounded by a wall 3 and provided above with a top chamber 4. The bottom chamber 2 is at its lower end provided with an outlet 10 with a valve mechanism 23 so that particles may be discharged if necessary. At a predetermined distance above the outlet 10 a manifold 22, tuyere or a plenum chamber with jets for the introduction of air or gas for fluidization is arranged. In the region below the manifold 22 the particles will be unfluidized unless other means for fluidization are provided here, but the particles may slide downwards by the effect of gravity towards the outlet 10 when the valve mechanism 23 is opened. Particulate material, which may comprise fuel, inert particles such as said suitable reactants for binding of undesired matter, etc. are introduced through the inlet 9. Further inlets 11 for secondary reactor air may optionally be provided, whereby a slow fluid-bed may be maintained at the reactor bottom, while a faster fluid-bed is maintained above the secondary air inlet. Solid particles are elutriated by the air flow and entrained upwards into the top chamber, in which the air velocity drops because of the larger cross-sectional area of the top chamber, whereby particles move out towards the sides and may drop down there. The top chamber is provided with an exhaust duct 28 for flue gas, which duct may be provided with deflectors or baffles (not shown) in order to reduce the amount of particles carried out with the flue gas. The exhaust duct 28 may optionally lead through a cyclone 15 for further separation of solid particles from the flue gas. The flue gas exits the cyclone 15 through the duct 16, while the solid particles exit the cyclone at the cyclone bottom 17 and are carried through ducts 20 back to the fluid-bed reactor at suitable positions. The cyclone may be provided with a lower outlet 19, from which particles may be taken away from the fluid-bed circulation, and all particle outlets from the cyclone are provided with control valves 18 to allow full control of the particle flow. Particulate material carried up from the primary fluid-bed 29 and into the top chamber will for the greater part drop adjacent the sides and thereby drop onto the secondary fluid-bed 30 or fluid-bed cooler surrounding the primary bed 29 wall 3. Particulate material within the secondary fluid-bed 30 is fluidized by blowing of gas or air through an air plenum chamber with jets 12. The secondary fluid-bed is provided with heat transfer tubes 21 for cooling particulate material. Particulates may flow from the secondary fluid-bed and downwards through ducts or downcomers 5 past control valves 6 to return to the primary fluid-bed. The secondary fluid-bed may be provided with inlets 8 for the introduction of suitable reactants. Heat in the flue gas leaving the cyclone is also recovered by passing the flue gas past further heat transfer surfaces, e.g. an evaporator 26 and a preheater or economizer 27.
Reference is now made to FIG. 2, showing a horizontal section through the reactor along the line II--II of FIG. 1, showing how the secondary bed or the bed cooler 30 is divided into three sections 31, 32 and 33 designated the evaporator section 31, the super-heater section 32 and the storage section 33, respectively. The sections are advantageously separated by radial partition walls 13, each section being provided with a downcomer 5 for returning particles to the primary bed. The figure shows heat transfer tubes 21 in the evaporator section and in the super-heater section. All three of the sections are provided with fluidization gas jets, but it is optionally possible to dispense with fluidization jets in the storage section, in which case the particle material moves down to the downcomer by the force of gravity.
As it may be seen at the left-hand portion of FIG. 1 the partition walls 13 between the sections of the fluid-bed cooler have a top edge at a level lower than that of the wall 3 separating the cooler from the primary reactor in order to make it possible for particles to flow over a partitioning wall 13 into an adjacent section.
In a practical embodiment of the fluid-bed cooler the evaporator section extends over 150 angular degrees, the super-heater over 120 degrees and the storage section over 90 degrees, but obviously these sizes and forms could be modified in numerous ways.
The advantages gained through the facilities allowing various modes of operation may be understood from the following explanation. Supposing the reactor is to operate on partial load, the amount of particles actively circulated must be relatively large due to the higher density of the beds. This is achieved very simply by reducing the amount of particles in the storage section, i.e. the control valve 6 for the downcomer 5 from the storage section will be fully opened and the control valve 14 for fluidization gas into the storage section is also fully opened in order to keep the density within the storage section of the secondary bed as low as possible. The particles in the evaporator section and in the super-heater section are fluidized with a flow of fluidization gas, which is kept to the minimum determined by the request for obtaining sufficient heat transfer. This is possible by fluidization velocities as low as 5 cm per second for a mean particle diameter in the order of 160 μm. In order to avoid erosion and corrosion the amount of particles within the evaporator section and in the super-heater section is kept sufficient to cover the heat transfer surfaces completely. A fine tuning of the heat transfer within each of the cooling sections is possible by the control of the particle flow and the control of the fluidization gas velocity.
Supposing alternatively that the reactor is operating at full load, the density of the particles within the fluid-beds is lower and the amount of particles actively circulated must therefore also be lower in order to obtain the optimum combustion efficiency. This is obtained by closing or partially closing the outlet valve 6 from the storage section and also closing or partially closing the control valve 14 for introduction of fluidization gas to this section so that the amount of particles within the storage section is increased with particles taken away from active circulation in the reactor to the extent necessary. It is obvious that a superior efficiency of the combustion may be obtained when operating at full load as well as when operating at partial load and that the reactor may operate efficiently at a lower load factor than economically feasible with fluid-bed reactors of the prior art.
The flow control facility and the facility for removing portions of the particles from the active circulation respectively to reintroduce them furthermore makes it possible to carry out the start-up or adjustments of the load at a faster rate than possible with reactors of the prior art.
Reference is now made to FIG. 3, showing a vertical section through a fluid-bed combustion reactor according to a preferred embodiment of the invention. This reactor 51 comprises as shown in the figure a bottom chamber 52 defined by a wall 53 and with a top chamber 54 arranged thereabove. The bottom chamber 52 is at the lower end provided with a discharge opening 50 with a valve mechanism 63 to allow removal of particle matters and ashes if necessary.
At a predetermined distance above the bottom outlet opening 50 a manifold or a plenum chamber 22 with jets for the introduction of fluidization air or fluidization gas is arranged. At the area below the manifold 22 the particles will not be fluidized unless other fluidization means are provided here, but the particles may slide downwards to the discharge opening 50 when the valve mechanism 63 is opened.
Similarly to the reactor of FIG. 1 the FIG. 3 reactor 51 is also provided with inlet ducts 9 for the introduction of particles, which may comprise fuel, inert particles, suitable reactants for the binding of undesired matter etc. Further inlets 11 for secondary reactor air may be arranged in order to allow the maintaining of a slow fluid-bed at the bottom, while a faster fluid-bed is maintained above the secondary air inlets similarly to the design of the FIG. 1 embodiment. Above the inlet 11 for secondary reactor air a further upper inlet 66 for the introduction of particulate material such as fuel, inert particles, suitable reactants for the binding of undesired matter etc. may be arranged as it may be advantageous to have the possibility of selecting between various levels of introduction of such particles.
The fluidization jets are provided with air from blowers, each blower being provided with means to control the blow power and each designated with the reference numeral 45. At sufficient power of introduction of fluidization air solid particles will be suspended by the gas flow and entrained by elutriation to arrive at the top chamber, where the flow is deflected sidewards by a deflector 41. The top chamber 54 has a larger cross-sectional area than the reactor lower portion 52 and the gas velocity will therefore decrease in the top chamber. The gas may flow around the deflector 41 to enter the exhaust duct 28 for flue gas. Due to the decreasing gas velocity in the top chamber and due to the change of flow direction a substantial proportion of the particulate material entrained with the gas will drop down into the particulate cooler 42 arranged below the top chamber.
Exhaust gas will exit through the exhaust duct 28 to arrive at the cyclone 15, where further separation of solid particles from the exhaust gas takes place. Gas exits the cyclone 15 through the duct 16 and flows past further cooling surfaces, e.g. evaporator tubes 26, a pre-heater or economizer 27 and an air pre-heater 25. Particles separated from the exhaust gas in the cyclone 15 exits the cyclone at the bottom 17 and may move downwards through the downcomer 67 from the cyclone to be reintroduced into the primary reactor 51.
Particles dropped down into the particle cooler 42 may move downwards herein in a way to be explained in more detail below and flow through a downcomer 56 returning the particles for reintroduction into the primary reactor 53. As shown in FIG. 3 the particle cooler is provided with a controllable blower 45 blowing fluidization air through conduits 46 upwards through the particle cooler through fluidization jets 60 in order to fluidize the bulk of particles in the particle cooler 42. The upper surface of the bulk of particles in the particle cooler is shown at 73.
Reference is now made to FIG. 4, showing a plan sectional view through the reactor along the line IV--IV of FIG. 3. As may be seen from FIG. 4 the reactor is substantially rectangular and the particle cooler 42 is also substantially rectangular and arranged adjacent the reactor sides and with one side parallel to the side of the reactor. The particle cooler comprises bottom wall 68 and side walls 69. As shown in the figure the particle cooler is provided with coolant tubes in a serpentine pattern sectionalized into two sections, said sections being designated the evaporator tube coil 43 and the super-heater tube coil 44. These tube coils carry water and/or steam and the flow within each of the tube coils may be controlled separately. In the particle cooler 42 bottom 68 openings 70, 71 are provided for particle discharge. The opening 70 takes the particles down through a downcomer 55 from the super-heater section, while the opening 71 carries particles down through downcomer 56 from the evaporator section. The demarcation line between the two sections within the particle cooler 42 is indicated by a dashed line 72. As indicated in phantom both downcomers communicate with the reactor so that particles from both downcomers may be reintroduced into the reactor.
In FIG. 3 only one of the downcomers, i.e. the evaporator section downcomer 56, is shown shaped as an L with a relatively tall vertical portion and a relatively short horizontal portion at the lower end. The super-heater section downcomer 55 is similarly formed. As it may be seen in FIG. 3 an air jet 57 connected to a blower 45 with a blower control facility by a conduit 46 is arranged at the downcomer lower end. During normal operation the downcomer will be filled with particles up to a level above the coolant tube coils in the particle cooler. Blowing of air through the jet 57 will carry particles through the downcomer horizontal portion and into the reactor as the resistance to the air-blowing is lower this way. The pressure in the pillar of particles within the downcomer is normally so high that these particles will not be fluidized, but rather slide downwards slowly by gravity in proportion to the amount removed at the bottom. The inventor has found it possible by the controlled blowing of air through the air jet 57 to control the flow of particle material into the reactor in a very convenient way so that the arrangement with the jet 57 may be regarded as a type of valve controlling the particle return flow into the reactor.
It is understood that the other downcomer from the particle cooler 56 connected with the super-heater section is provided with a similar air jet 47 (cf. FIG. 5 and FIG. 6) and operates in a similar fashion so that reference may be made to the above description. Furthermore, the particle return conduit from the cyclone is similarly provided with an air-jet 74 and with a controllable blower 45 through corresponding air-conduits 46 so that the particle flow from the cyclone bottom returning to the reactor may be controlled in a similar fashion.
Reference is now made to FIG. 5, showing a vertical section through a particle cooler 42 with a super-heater section downcomer 55, an evaporator section downcomer 56, air-jets for the super-heater section downcomer 56 and air-jets for the evaporator section downcomer 57. In order to make the figure easily understandable the horizontal portions at the lower end of the downcomers are illustrated as extending sidewards in FIG. 5 and in FIG. 6, although these horizontal sections actually extend perpendicularly to the plane of the drawings in FIG. 5 and 6 as it may be understood by referring to FIG. 4.
FIG. 5 shows a section through the particle cooler bottom wall 68 and side walls 69 with integrated coolant tubes 21, which allows the temperature within the wall elements to remain within acceptable limits. The figure further shows the serpentine-like evaporator tube coil 43 and two serpentine-like super-heater tube coils 44, a first one of them arranged in the right-hand portion of the cooler as shown in FIG. 5, and a second one of them arranged in the left-hand portion of the cooler underneath the evaporator tube coil 43. For reasons of simplicity the sections of the particle cooler will be referred to as the superheater section and the evaporator section, although the evaporator section contains also a super-heater tube coil. Below the particle cooler bottom 68 blowers 45 with air conduits 46 connected with the super-heater section fluidization jets 60 and the evaporator section fluidization jets 61, respectively, are shown. By providing two blowers in this fashion the fluidization within the two sections may be controlled separately as the inventor has discovered that the fluidization gas flows essentially vertically upwards through the bulk of particles. The fluidization jets are shown symbolically in the figure as the real cooler is provided with a large number of jets arranged with close spacings all over the cooler bottom except for a region along the midst, i.e. along the section line 72 of demarcation, where the fluidization jets are omitted.
FIG. 5 shows fluidized particle areas 64, while there is a portion of particles 65, which is not fluidized. It is understood, referring also to FIG. 3 and FIG. 4, that the particle cooler during normal reactor operation receives a continuous flow of heated particles spread substantially all over the particle cooler 42 surface. FIG. 1 illustrates a mode of operation, where the levels of the particle matter within the two sections of the particle cooler 42 are not equal. This may be the case in a mode of operation where more air is blown through the air jet 47 into the super-heater section downcomer 56 than blown through the air-jet 57 into the evaporator section downcomer 56. Hereby a greater amount of particles are removed from the super-heater section. The difference between the levels of particles makes the "wall" of unfluidized particulate material 65 slide slowly towards the right in the figure, whereby naturally particles of the wall will gradually be fluidized as they move into a region over fluidization jets. Within each of the sections the fluidization gas provides agitation and circulation of the particles, whereas the wall of unfluidized particles 65 between the sections keeps them separated so that an unidirectional gradual and controlled flow across the line of demarcation is achieved, e.g. a net transfer of particles and thus of heat from one section to another. In the mode of operation illustrated the particle flow around the evaporator tube coils will be low so that the heat transfer to the evaporator tubes will be low, whereas the particle flow around the super-heater tube coils is high so that the heat transfer to super-heater tubes is higher. In order to achieve an even larger difference in the heat transfer rates the inflow of fluidization gas into the super-heater section through the air jet 60 may be increased to agitate the particles within this section more. The inflow of fluidization gas through the evaporator section jet 61 is decreased to a level where the gas flow just fluidizes the particles within the section. At this flow level the coefficient of heat transfer to the evaporator tubes is low causing an even further decrease in the heat-energy transferred to the evaporator tubes.
It is obvious from FIG. 5 and from the above given explanation that other modes of operation equally well could be selected, e.g. a mode where a greater heat transfer into the evaporator tubes takes place or a mode of operation with equal flow in the two sections and equal heat transfer rates.
Reference is now made to FIG. 6, showing another preferred embodiment of the particle cooler according to the invention. Most of the parts in the FIG. 6 embodiment are identical to those of the FIG. 5 embodiment, but the embodiment of FIG. 6 is provided with a section partition wall 62 along the section line 72 of demarcation. This section partition wall 62 is low compared to the cooler side walls so that particles may flow over the partition wall 62 in case the levels differ so as to provoke such flow. Obviously, the region above this section partition wall will contain unfluidized particles 65. All other elements of the embodiment in FIG. 6 are equivalent to those in FIG. 5 so that reference may be made to the above-given explanation. It is understood that the embodiment of FIG. 6 provides for a very distinct separation of the two sections whereby the heat exchange between the particles of the two sections is reduced.
Although different embodiments of the invention have been illustrated and described in detail, the invention is not to be considered as limited to the precise constructions and embodiments disclosed and various adaptations, modifications and uses of the invention, which may occur to those skilled in the art, to which the invention relates, may be made without departing from the spirit and scope of the invention. | A fluid-bed combustion reactor (51) comprising a substantially vertical reactor chamber with a first inlet (9) at the reactor chamber lower portion (52) for the introduction of liquid and/or solid particulate material, and a second inlet (22) at a level below the first inlet for the introduction of gas for fluidization of particulate material within the reactor in order to maintain a primary fluid bed, an exhaust duct (28) at the reactor chamber upper portion for the withdrawal of exhaust gas and particles from the reactor, and a fluid-bed cooler (42) for particular material, formed as an upwards open vessel with generally closed bottom and side walls and arranged so as to collect a portion of particulate material (64, 65) from the reactor chamber upper portion, said cooler comprising heat transfer means (43) such as tubes carrying a heat transfer medium at the inside and having said particulate material flowing at the outside, said cooler comprising at least one conduit (56) for the controlled returning of particulate material from the cooler to the primary fluid bed, and said cooler having inlets at the bottom wall (68) for introduction of gas for fluidization of particulate material. The heat transfer means are divided into at least two sections, and the inlets for fluidization gas are divided into sections corresponding with the heat transfer means sections and provided with separate control means for the inflow of fluidization gas into each section. | 5 |
FIELD OF THE INVENTION
[0001] This invention relates to a thermosetting resin, particularly to a polyimide resin having thermosetting functional groups which give a cured film with excellent heat resistance, mechanical strength, solvent resistance, and adhesion to a various kinds of substrates by heating at a low temperature for a short period of time. In addition, the resin is highly transparent in the visible light region and soluble in solvents.
DESCRIPTION OF THE PRIOR ART
[0002] A polyimide resin is widely used as a resin varnish for electronic parts etc., because it is excellent in heat resistance and electric insulation. However, the polyimide resin dissolves only in a limited number of organic solvents having high boiling points. Therefore, generally, a polyamic acid which is a polyimide precursor and relatively easily soluble in various kinds of organic solvents is applied on a substrate and, then, heated at 300 degrees C. or higher for a long period of time to dehydrate into a polyimide. This dehydration of the polyamic acid to a polyimide requires a long time of heating at a high temperature, which tends to degrade the substrate. If the heating is not enough, a portion of the polyamic acid remains in the resulting resin, making the resin less moisture resistant and corrosion resistant.
[0003] A method is known in which a polyimide resin film is made by applying a solution of an organic-solvent soluble polyimide resin, instead of a polyamic acid, on a substrate and heating it to evaporate the solvent (see, e.g., Japanese Patent Application Laid-open No. 61-83228, No.61-118424, No.61-118425, and No.02-36232.) However, the films obtained from these polyimide resins soluble in an organic solvent have poor solvent resistance. Japanese Patent Application Laid-open No. 10-195278 describes a thermosetting polyimide resin composition which is to be cured by heating at a relatively low temperature for a short period of time to form a polyimide resin film with a good adhesion property and solvent resistance.
[0004] Meanwhile, the polyimide resins have color, which limits their applications, although they have excellent physical properties. For this reason, a transparent and colorless polyimide has been strongly desired. At present, transparent polyimide resins are used for alignment layers for liquid crystals and so on. However, all of them are thermoplastic and do not have good heat resistance.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a polyimidesilicone resin having thermosetting functional groups which give a cured film with excellent heat resistance, mechanical strength, solvent resistance, and adhesion to a various kinds of substrates by heating at a low temperature for a short period of time. The resin has no color and an excellent transparency in the visible light region of from 400 nm to 700 nm and solubility in solvents.
[0006] As a result of extensive researches, the inventors have found that the above object can be attained by introducing specific molecular structures in a polyimide resin. Thus, the present invention provides a colorless and transparent thermosetting polyimidesilicone resin and a method of producing the same, which resin comprises structural units of the following general formula (1) and structural units of formula (4), and is soluble in an organic solvent.
[0007] wherein X is a tetravalent organic group having 4 or more carbon atoms, none of the carbon atoms of X being bound to a plurality of carbonyl groups, and Y is a diamine residue of the general formula (2) or (3),
[0008] wherein each of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 is independently selected from the group consisting of a hydrogen atom and alkyl groups having atoms, 1 to 6 carbon atoms,
[0009] wherein each of R 7 and R 8 is independently selected from the group consisting of a hydrogen atom and alkyl groups having 1 to 6 carbon atoms;
[0010] wherein X is a tetravalent organic group having 4 or more carbon atoms, none of the carbon atoms of X being bound to a plurality of carbonyl groups, and Z is a diamine residue of the general formula (5),
[0011] wherein each of R 9 , R 10 , R 11 , and R 12 is independently selected from the group consisting of substituted or non-substituted monovalent hydrocarbon groups having 1 to 8 carbon atoms, and “a” is an integer of from 1 to 100.
[0012] To attain the object of the present invention, a polyimidesilicone resin is preferably used in which the amount of the diamine residues of the general formula (2) or (3) is from 5 mole % to 95 mole % and the amount of the diamine residue of the general formula (5) is from 95 mole % to 5mole %, based on the total amount of the diamine residues, and which has a transmittance, measured in a form of a film of 10 μm thickness on a glass substrate of 1 mm thickness, of 80% or higher in the wavelength region from400 nm to 700 nm. The present invention also provides a semiconductor device or a display apparatus which comprises the aforesaid polyimidesilicone resin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 shows an infrared absorption spectrum of the imidesilicone resin prepared in Example 1.
[0014] [0014]FIG. 2 shows a transmission spectrum of the imidesilicone resin prepared in Example 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The present invention will be explained further in detail. The present polyimidesilicone resin is a reaction product of a tetracarboxylic dianhydride and a diamine, characterized in that the resin contains thermosetting groups, and is soluble in an organic solvent and transparent.
[0016] There are known thermosetting groups such as a carboxyl group, amino group, epoxy group, and hydroxyl group. In view of the production process of the present polyimide, a phenol group may be selected in the present invention, because it does not react easily with a carboxyl group or an amino group.
[0017] The diamine, a raw material for the present polyimidesilicone resin, will be explained below. In a preferred embodiment of the present invention, a diamine is used which has phenol groups in the diamine residue. For example, the one having a diamine residue of the general formula (2) or (3) is used in the present invention.
[0018] In the formula (2), each of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 is independently selected from the group consisting of a hydrogen atom and alkyl groups having 1 to 6 carbon atoms. The examples of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 include methyl, ethyl, propyl, butyl, pentyl, and hexyl group, among which methyl group is preferred.
[0019] In the formula (3), each of R 7 and R 8 a is independently selected from the group consisting of a hydrogen atom and alkyl groups having 1 to 6 carbon atoms. The examples of R 7 and R 8 include methyl, ethyl, propyl, butyl, pentyl, and hexyl group, among which methyl group is preferred.
[0020] An amount of the diamine residue having phenol groups may be in the range of from 5 mole % to 95 mole %, preferably from 20 mole % to 80 mole %, based on the total amount of the diamine residues. If the amount is below 5 mole %, a film cured with a substance reactive with the phenol groups, such as an epoxy compound, may have a low density of crosslinkage, so that the film may not be sufficiently resistant to solvents. If the amount exceeds 95 mole %, an amount of diaminosiloxane is so small that solubility of the resultant polyimide resin in organic solvents is lower and adhesion of the cured film to a substrate is poorer.
[0021] In a preferred embodiment of the invention, a diamine further comprising a diaminosiloxane residue is used. An example of such a diamine is represented by the general formula (5).
[0022] In the formula (5), each of R 9 , R 10 , R 11 , and R 12 is independently selected from the group consisting of substituted or unsubstituted monovalent hydrocarbon groups having 1 to 8 carbon atoms, for example, alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl groups; alicyclic groups such as cyclopentyl and cyclohexyl groups; aryl groups such as phenyl and xylyl groups; aralkyl groups such as benzyl and phenetyl groups; halogenated alkyl groups such as 3,3,3-trifluoropropyl and 3-chloropropyl groups; trialkoxysilylalkyl groups such as 2-(trimethoxysilyl)ethyl group; alkoxy groups such as methoxy, ethoxy, and propoxy groups; aryloxy groups such as phenoxy group; and cyano group. Among these, ethyl and phenyl groups are preferred. In the formula (5), “a” is an integer of from 1 to 100.
[0023] An amount of the diaminosiloxane residue may range from 5 mole % to 95 mole %, preferably from 10 mole % to 90 mole %, based on the total amount of the diamine residues. If the amount is below 5 mole %, solubility of a resultant polyimidesilicone resin in organic acids is undesirably low. If the amount exceeds 95 mole %, the polyimidesilicone resin obtained is difficult to handle, and, due to a lower content of curable groups, the resin may not form a cured film having a good adhesion property. By using the diaminosiloxane, the solubility of the resin obtained in organic solvents and the adhesion property to a various kinds of substrates are improved.
[0024] In order to obtain the polyimidesilicone resin colorless and transparent in the visible light region, these diamines are preferably colorless and transparent.
[0025] In addition to the above diamines, any known diamines for a general use can be used together for preparing the present polyimidesilicon resin in such an amount that the colorlessness and transparency of the resin is not damaged. Examples of such diamines include aliphatic diamines such as tetrametylenediamine, 1,4-diaminocyclohexane, and 4,4′-diaminodicyclohexylmetahne; and aromatic diamines such as phenylenediamine, 4,4′-diaminodiphenylether, and 2;2-bis(4-aminophenyl) propane. These can be used alone or in a mixture of two or more of them.
[0026] The tetracarboxylic dianhydride, another raw material for the present polyimidesilicone resin, will be explained below. The present polyimidesilicone resin is characterized in that it is colorless and transparent in the visible light region. Accordingly, it is preferred that the tetracarboxylic dianhydride as a raw material for the resin is colorless and transparent, or forms a less amount of charge transfer complexes known to cause discoloration. Aliphatic tetracarboxylic dianhydrides and alicyclic tetracarboxylic dianhydrides are preferred because of their superior colorlessness and transparency. However, aromatic tetracarboxylic dianhydrides which have superior heat resistance may be used in such an amount that they db not cause discoloration.
[0027] Examples of the aliphatic tetracarboxylic dianhydrides include butane-2,3,4-tetracarboxylic dianhydride and pentane-1,2,4,5-tetracarboxylic dianhydride. Examples of the alicyclic tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, dicyclohexyl-3,4,3′,4′-tetracarboxylic dianhydride, bicyclo[2.2.l]heptane-2,3,5,6-tetracarboxylic dianhydride, and 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride. Examples of the aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 4,4′-hexafluoropropylidenebisphthalic dianhydride, and 3,3′,4,4′-diphenyl sulfone tetracarboxylic dianhydride. Aliphatic tetracarboxylic dianhydrides having an aromatic ring may be used, such as, for example, 3a,4,5, 9b-tetrahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2 -c]furan-1,3-dione, and 3a,4,5,9b-tetrahydro-5-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione. These tetracarboxylic dianydrides may be used alone or in a mixture of two or more of them.
[0028] The present polyimidesilicone resin may be prepared in an one-step process in which diamine and tetracarboxylic dianhydride are reacted in approximately equimolar amounts in the presence of a solvent only at a high temperature, or in a two-step process in which a polyamic acid is prepared at a lower temperature in the first step and, then, the polyamic acid is imidized at a higher temperature.
[0029] A ratio of the diamine component to the tetracarboxylic dianhydride component is determined according to a desired molecular weight of the polyimidesilicone resin and so on. Typically, the molar ratio ranges from 0.95 to 1.05, preferably 0.98 to 1.02. To adjust a molecular weight of the polyimidesilicone resin, a mono-functional raw material such as phthalic anhydride and aniline can be used. The amount of the mono-functional raw material is preferably 2 mole % or lower based on the total amount of the mono- and di-functional raw materials.
[0030] In the one-step process, a reaction temperature ranges from 150 to 300 degrees C., and a reaction time ranges from 1 to 15 hours. In the two-step process, the polyamic acid preparation is performed at a temperature of from 0 to 1.20 degrees C. for 1 to 100 hours and, then, the imidization process is performed at a temperature of from 0 to 300 degrees C. for 1 to 15 hours.
[0031] In the preparation process, any solvent can be used which is miscible with the raw materials, i.e., the diamine and the tetracarboxylic anhydride, and the reaction product, i.e., the polyimidesilicone. Examples of such a solvent include phenols such as phenol, 4-methoxyphenol, 2, 6-dimethylphenol, and m-cresol; ethers such as tetrahydrofuran and anisole; ketones such as cyclohexanone, 2-butanone, methyl isobutyl ketone, 2-heptanone, 2-octanone, and acetophenone; ethers such as butyl acetate, methyl benzoate, and γ-butyrolactone; cellosolves such as butylcellosolve acetate, and propylene glycol monomethyl ether acetate, amides such as N,N-dimethylformamide, N,N-dimethylacetoamide, and N-methyl-2-pyrrolidone.
[0032] Together with the aforesaid solvent, aromatic hydrocarbons such as toluene and xylene can be used to make an azeotrope with water produced in the imidization process to thereby remove the water with ease. These solvents can be used alone or in a mixture of two or more of them.
[0033] When plural species of at least one of the diamine and the carboxylic dianhydride is used, there is not added any particular limitation on the process. Use is made of, for instance, a method in which all of the raw materials are mixed together in advance and polycondensed simultaneously, and a method in which each of two or more diamines of tetracarboxylic anhydrides is added sequentially to react separately.
[0034] In the imidization process, a dehydrating agent and an imidization catalyst may be added to the reaction mixture and, if needed, heated. Examples of the dehydrating agent include acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride. Preferably, the dehydrating agent is added in an amount of from 1 to 10 moles per mole of the diamine.
[0035] Examples of the imidization catalyst include tertiary amines such as pyridine, corydine, lutidine, and triethylamine. The imidization catalyst is added preferably in an amount of from 0.5 to 10 moles per mole of the dehydrating agent.
[0036] The present polyimidesilicone resin has excellent solubility, so that it can be dissolved in an organic solvent to provide a solution with a viscosity suited to be applied on a specific substrate.
[0037] A solvent to dissolve the present polyimidesilicone resin may be those which can be used in the preparation processes, or other aromatic hydrocarbon solvents and ketone solvents, as far as these can dissolve the present polyimidesilicone.
[0038] Particularly, when it is desired to dissolve the polyimidesilicone in an aromatic hydrocarbon or ketone solvent having a low boiling point, synthesized polyimidesilicone resin is purified by, for example, reprecipitation with a poor solvent, and then can be re-dissolved in such a solvent.
[0039] The present polyimidesilicone resin can be applied on any substrate, e.g. metals such as iron, copper, nickel, and aluminum; inorganic substrates such as glass; and organic resins such as epoxy resin and acrylic resins.
[0040] The thermosetting property of the present polyimidesilicone can be improved, by adding a substance reactive with the phenol groups of the polyimidesilicone resin. Examples of such a substance include polyfunctional organic substances, e.g., resins and oligomers having a plurality of functional groups reactive with a phenol group, such as carboxyl, amino, and epoxy groups.
[0041] After cured by heating, the present polyimidesilicone resin shows excellent heat resistance, mechanical strength, solvent resistance, and adhesion to a various kinds of substrates.
[0042] The curing conditions are not limited to particular ones. Typically, a curing temperature ranges from 80 to 300 degrees C., preferably from 100 to 250 degrees C. If the temperature is below 80 degrees C., an impractically long time is required for curing or the cured film would have low storage stability. Unlike the conventional polyamic acid solution, the present polyimidesilicone resin may not require a long curing at a temperature so high as above 300 degrees C., so that thermal degradation of a substrate can be prevented.
[0043] The present polyimidesilicone resin is characterized by a transmittance of 80% or higher in the visible wave length region of from 400 nm to 700 nm when measured in a form of a film of 10 μm thickness on a 1-mm thick glass substrate by UV/Visible absorption spectrometry.
[0044] The present highly transparent, thermosetting polyimidesilicone soluble in solvents can be used for protective films for color filters, light emitting diodes, and laser diodes in semiconductor devices; alignment layers for liquid crystals of liquid crystal displays; and in various kinds of electronic or optical apparatuses.
EXAMPLES
Example 1
Synthesis of a Polyimidesilicone Resin
[0045] In a flask provided with a stirrer, a thermometer, and nitrogen purge equipment, 30.0 g, i.e., 0.1 mole, of 3a,4,5,9b-tetrahydxo-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, and 250 g of N,N-dimethylacetamide were fed and mixed to dissolve. To the solution, 17.3 g, i.e., 0.035 mole, of 2,2′-methylenebis[6-(4-amino-3,5-dimethylbenzyl)-4-methyl]phenol was added. The reaction mixture was kept at 50 degrees C. for 3 hours. Then, 56.2g, i.e. 0.065 mole, of diaminosiloxane of the general formula (5), where “a” is 9.5 on average, was added drop wise at room temperature. After the addition was completed, the reaction mixture was stirred at room temperature for 12 hours.
[0046] Subsequently, a reflux condenser provided with a water receptor was attached to the flask and, then, 50 g of toluene was added. After the temperature was raised to 170 degrees C. and kept at that temperature for 6 hours, an almost clear solution was obtained.
[0047] The solution thus obtained was put in methanol, a poor solvent, to thereby precipitate. FIG. 1 shows an infrared absorption spectrum of the resin. There was not a peak, based on the polyamic acid, which indicates the presence of unreacted functional groups, and the absorption bands of imide group were observed at 1770 cm −1 and 1710 cm −1 . The resin obtained had the structure of the formula (I) having the two repeating units.
[0048] wherein, X is
[0049] Y is
[0050] and Z is
[0051] A weight average molecular weight of the resin, reduced to polystyrene, was 11,000, which was determined by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. A film of 70 μm thickness was made by applying a methyl isobutyl ketone solution of the resin on a glass substrate with dimensions of 25 mm by 75 mm and a thickness of 1 mm, and drying the applied film. FIG. 2 shows a transmission spectrum of the film on the glass substrate. The transmittance at the wavelength of from 400 nm to 700 nm was 80% or higher, while that of the blank transmittance of the glass substrate ranges from 88 to 90%.
Example 2
Synthesis of a Polyimidesilicone Resin
[0052] In a flask provided with a stirrer, a thermometer, and nitrogen purge equipment, 30.0 g, i.e., 0.1 mole, of 3a,4,5,9b-tetrahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, and 250 g of N,N-dimethylacetamide were fed and mixed to dissolve. To the solution, 34.6 g, i.e., 0.07 mole, of 2,2′-methylenebis[6-(4-amino-3,5-dimethylbenzyl)-4-methyl]phenol was added. The reaction mixture was kept at 50 degrees C. for 3 hours. Then, 26 g, i.e. 0.03 mole, of diaminosiloxane of the general formula (5), where “a” is 9.5on average, was added drop wise a room temperature. After the addition was completed, the reaction mixture was stirred at room temperature for 12 hours.
[0053] Subsequently, a reflux condenser provided with a water receptor was attached to the flask and, then, 50 g of toluene was added. After the temperature was raised to 170 degrees C. and kept at that temperature for 6 hours, an almost clear solution was obtained.
[0054] The solution thus obtained was put in methanol, a poor solvent, to thereby precipitate. In an infrared absorption spectrum of the resin, there was not a peak, based on the polyamic acid, which indicates the presence of unreacted functional groups, and the absorption bands of imide group were observed at 1770 cm −1 and 1710 cm −1 . The resin obtained had the structure of the formula (II) having the two repeating units.
[0055] wherein, X is
[0056] Y is
[0057] and Z is
[0058] A weight average molecular weight of the resin, reduced to polystyrene, was 7,000, which was determined by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. A film of 30 μm thickness was made by applying a methyl isobutyl ketone solution of the resin on a 1-mm thick glass substrate and drying the applied film. The film on the glass substrate had a transmittance of 80% or higher at the wavelength of from 400 nm to 700 nm.
Example 3
Synthesis of a Polyimidesilicone Resin
[0059] In a flask provided with a stirrer, a thermometer, and nitrogen purge equipment, 30.0 g, i.e., 0.1 mole, of 3a,4,5,9b-tetrahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 250 g of N,N-dimethylacetamide and 100 g of toluene were fed and mixed to dissolve. To the solution, 12.35 g, i.e., 0.025 mole, of 2,2′-methylenebis[6-(4-amino-3, 5-dimethylbenzyl)-4-methyl]phenol was added. The reaction mixture was kept at 50 degrees C. for 3 hours. Then, 64.88 g, i.e., 0.075 mole of diaminosiloxane of the general formula (5), where“a” is 9.5 on average, was added drop wise at room temperature. After the addition was completed, the reaction mixture was stirred at room temperature for 12 hours.
[0060] Subsequently, a reflux condenser provided with a water receptor was attached to the flask and, then, 20.4 g of acetic anhydrous and 26.4 g of pyridine were added. The temperature was raised to 50 degrees C. and kept at that temperature for 3 hours.
[0061] The solution thus obtained was put in methanol, a poor solvent, to thereby precipitate. In an infrared absorption spectrum of the resin, there was not a peak, based on the polyamic acid, which indicates the presence of unreacted functional groups, and the absorption bands of imide group were observed at 1770 cm −1 and 1710 cm −1 . The resin obtained had the structure of the formula (III) having the two repeating units.
[0062] wherein, X is
[0063] Y is
[0064] and Z is
[0065] A weight average molecular weight of the resin, reduced to polystyrene, was 24,000 which was determined by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. A film of 50 μm thickness was made by applying a methyl isobutyl ketone solution of the resin on a 1 mm thick glass substrate and drying the coating film. The film on the glass had a transmittance of 80% or higher at the wavelength of from 400 nm to 700 nm.
Example 4
Evaluation of the Cured Resin
[0066] To 100 parts by weight of the polyimidesilicone resin prepared in Example 1, 10 parts by weight of an epoxy, N,N-diglycidyl-4-glycidyloxyaniline, was added and the mixture was dissolved in methyl isobutyl ketone. The methyl isobutyl ketone solution obtained was applied on a copper plate with a bar coater and the applied film was cured at 150 degrees C. for 2 hours. The cured film was aged in an environment of 85 degrees C. and 85% RH for a week. The film did not peel off and the copper plate did not rust. Then, the cured film was soaked in methyl ethyl ketone for 5 minutes. The surface of the film was not damaged at all.
INDUSTRIAL APPLICABILITY
[0067] The present thermosetting polyimidesilicone resin is transparent and soluble in solvents. It can be cured at a relatively low temperature for a short period of time. The cured film has excellent heat resistance, mechanical strength, solvent resistance, and adhesion to a various kinds of substrates. It is advantageously used for protective films for color filters, light emitting diodes, and laser diodes in semiconductor devices; alignment layers for liquid crystals in liquid crystal displays; and in various kinds of electronic or optical apparatuses. | A colorless and transparent thermosetting polyimidesilicone resin comprising structural units of the following general formula (1) and structural units of the general formula (4), said resin being soluble in an organic solvent
wherein X is a tetravalent organic group having 4 or more carbon atoms, none of the carbon atoms of X being bound to a plurality of carbonyl groups, Y is a diamine residue and Z is a diaminosiloxane residue. | 2 |
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of official duties by employees of the Department of the Navy and may be manufactured, used, licensed by or for the U.S. Government for any governmental purpose without payment of any royalties thereon.
FIELD OF THE INVENTION
The invention is related to the field of aircraft ordnance and more particularly to the arming of stores loaded on aircraft ejection racks.
BACKGROUND OF THE INVENTION
Currently, aircraft ordnance is armed by extracting arming wires from various ordnance devices as the ordnance separates from the aircraft ejection rack. Until removed, the arming wire acts as a safety pin physically preventing the arming activation mechanism from functioning. The activation devices controlled by the arming wires may be fuzes, high drag fin assemblies or any other pin restrained devices. Requiring separation ensures that the ordnance remains unarmed until it is free of the aircraft.
In a conventional ordnance ejection rack, arming wire installation and connections control how weapons are armed. The arming wires may be connected by one of two techniques, either to positive arming latches or to arming solenoids. Positive arming latches are fixed latches which extract the arming wires whenever the ordnance is released and separates from the aircraft. The arming solenoids, on the other hand, provide the pilot control over the retention or release of the respective arming wires. If the pilot selects an arming solenoid by applying power to it, the arming solenoid will retain the arming wire causing it to be extracted from the ordnance device arming activation mechanism as the ordnance separates from the aircraft. If the pilot does not select an arming solenoid, the ordnance will be released with that arming solenoid's arming wire intact; that is, the ordnance device in which the released arming wire is installed remains unarmed.
There are numerous deficiencies associated with arming wire ordnance activation which can reduce weapon effectiveness, decrease safety and damage aircraft. These deficiencies include:
1. complicated installation procedures which are labor intensive and prone to error;
2. unreliable operation of pilot selected arming solenoids;
3. improper arming caused by defective arming wires which may break before being extracted from the ordnance device;
4. damage to composite material or paint removal from the aircraft caused by the airstream whipping broken arming wires against the aircraft skin; and
5. damage to the aircraft caused by Fahnestock or safety clips which become airborne debris once the arming wire is extracted from the ordnance device activation mechanism.
SUMMARY OF THE INVENTION
The pyrofuze arming system is a new and novel electrically activated ordnance arming system for controlling ordnance on an aircraft. An object of the pyrofuze ordnance arming system is to functionally replace the arming wire connections between the aircraft ejection rack and the ordnance. Another object of the system is to increase the safety and reliability of ordnance arming while decreasing the handling involved in preparing and loading ordnance. Yet another object of the pyrofuze ordnance arming system is to provide a retrofittable system for existing ejection racks designed to carry current inventory series ordnance. Still another object of the invention is to provide an electrically controllable device which functions as a safety pin for physically restraining various ordnance device arming activation mechanisms.
The invention comprises a separation-detection subsystem, a detection-initiation subsystem, an interconnect subsystem, and pyrofuze devices. The pyrofuze pin which is the essential element of the pyrofuze devices is disclosed in detail in a copending application entitled Pyrofuze Pin For Ordnance Activation, Ser. No. 07/470,190, filed Mar. 9, 1990, which is hereby incorporated by reference herein. In the normal sequence of operation of the system the separation-detection subsystem senses that ordnance has irrevocably separated from the ejection rack. Mechanical, electrical, magnetic and optical separation sensors may be employed. The detection-initiation subsystem then, through the interconnect subsystem, activates the pyrofuze devices and energizes the ordnance electrical fuze in response to data received from the separation-detection subsystem. The interconnect subsystem contains the umbilical cable which conducts power from the aircraft to the pyrofuze devices during the initial phase of the ordnance separating from the aircraft.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and numerous other advantages of the present invention will be readily understood from the following detailed description when read in view of the appended drawings wherein:
FIG. 1 is a block diagram of the pyrofuze ordnance arming system as applied to a gravity bomb outfitted with a nose fuze and a tail fuze.
FIG. 2 is a cross section of a side view of the pyrofuze device.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of the pyrofuze ordnance arming system, depicted generally by the numeral 10, illustrating a typical application of the system applied to a gravity type bomb fitted with a nose fuze 12 and a tail fuze 11. Power for the system is supplied from three sources: a constant 28 VDC supply 15 provided by the ordnance release switch 14, the aft arming solenoid power 16, and the forward arming solenoid power 18. The separation-detection subsystem 13 comprises the aft separation-detector 20 and the forward separation-detector 22 located on the ordnance ejection rack in juxtaposition with the forward and aft lugs 19 on the ordnance and which sense the release of the ordnance. The separation-detectors 20 and 22 are connected to detection-initiation circuitry by shielded cables 26. The detection-initiation subsystem 24 comprises the detection-initiation circuitry which processes the separation-detector data. Based on the detection results, the detection-initiation circuitry 24 switches initiation power through the interconnect subsystem 23 to pyrofuze devices 40 and switches the fuze function control set (FFCS) 17 to the electric fuze by means of an electrical switching device 21. The interconnect subsystem 23 is comprised of the shielded cable 28, the payout assembly 32, the umbilical cable 34, the Communication Link Replacement (COMM Link) 36, and the single conductor shielded cables 38. The multiple conductor shielded cable 28 conducts detection-initiation circuitry 24 output to payout assembly 32. One half of umbilical connector 30a is mounted on the end of the multiple conductor shielded cable 28 and is secured to a fixed point either on the aircraft or on the ordnance ejection rack. The mating half of the umbilical connector 30b is mounted to umbilical cable 34 which comprises a multiple conductor shielded cable. The umbilical cable 34 is stored in payout assembly 32 except for that portion which extends from the payout assembly 32 to Communication Link replacement (COMM LINK) 36 disposed on the ordnance. The shielding of the cable 34 is firmly attached to the mating half of umbilical connector 30b and to the COMM Link 36. The multiple conductors of umbilical cable 34 are separated in COMM Link 36 and routed to the appropriate terminals. Data from the aircraft fuze function control set (FFCS) 17 is connected to the ordnance internal wiring 44 through existing terminal 42 within the ordnance to the electrically operated tail fuze 11, in the fuzing configuration shown in FIG. 1. The other conductors of the umbilical cable 34 are connected to single conductor shielded cables 38 and routed externally around the ordnance to the pyrofuze devices 40. The pins 46 of the pyrofuze devices 40 are installed in an ordnance arming activation system 41 such as that on the tail fuze 11. Electrical power supplied by way of the umbilical cable 34 to the pyrofuze devices 40 is applied at the electrical leads 48 which connect internally to pyrofuze connections 50, as depicted in FIG. 2.
The mode of operation of the pyrofuze ordnance arming system 10 is based on the arming configuration selected by the pilot. The pyrofuze ordnance arming system is wired in parallel with the conventional arming wire system. The arrangement allows the option of arming the ordnance with the pyrofuze ordnance arming system or conventional arming wire system without any additional pilot input. However, only one system can be in use at one time.
The pyrofuze ordnance arming sequence begins by sensing the release of the ordnance with the separation-detection subsystem 13. The separation-detectors, aft 20 and forward 22, one each for the aft and forward lugs 19, respectively, on the ordnance, are mounted on the ejection rack and sense the presence of the weapon surface near each lug 19. If the weapon surface is present, the ordnance has not released.
The detection-initiation circuitry 24 has two functions. The first function uses a logic circuit 25 to process the data from each separation-detector 20 and 22. When each detector senses lug 19 separation from the ejection rack, the logic circuit will generate an enable signal. If one or both of the detectors sense a lug 9 present, the logic circuit 25 will not generate an enable signal. The enable signal controls the second function of the detection-initiation circuitry 24, namely, the power switching device 21 for the pyrofuze initiation channels. Therefore, ordnance can only be armed when a positive separation has occurred and an enable signal exists. An AND or similar type of logic circuit known to those skilled in the art may be used for processing the separation signals.
The enable signal activates all the pyrofuze initiation channels in the detection-initiation circuitry 24. The role of each channel, "positive arm" or "pilot selectable", is determined by the source of its power. The 28 VDC supply 15, activated by the ordnance release switch 14, powers the positive arming channels. The positive arming channels function whenever the ordnance is released and the enable signal is present.
Referring now to FIG. 1, the positive arming channels perform two functions. One function is the initiation of pyrofuze devices connected to the positive arming channel whenever the ordnance completely separates from the aircraft. The other function is to operate an electrical switching device 21 that passes the fuze function control set (FFCS) 17 signal to the electric fuze 11. Because the 28 VDC supply 15 is always present during weapons release, it is also used to power the separation-detectors 20 and 22 and the logic circuit 25 in the detection-initiation circuitry 24.
The selectable pyrofuze initiation channels derive their power from the arming solenoids at 16 and 18. In this way when an arming solenoid is selected, the corresponding initiation channel also has power. If an arming solenoid is not selected then its corresponding initiation channel will remain inactive after the enable signal is present.
The payout assembly 32 contains a multiple conductor shielded umbilical cable 34 that connects the detection-initiation circuitry 24 to the ordnance. When released, the ordnance pulls umbilical cable 34 from payout assembly 32. The umbilical connector 30 is pulled apart at connectors 30a and 30b when the umbilical cable 34 has traveled its length. Therefore, the length of the umbilical cable 34 governs the duration of the application of electrical power to the pyrofuze devices 40. Since the alloying reaction of the pyrofuze pin 46 results in the disintegration and elimination of the pin allowing the arming sequence to begin, the umbilical cable 34 must be of sufficient length to allow electrothermal initiation of the alloying reaction in the pyrofuze devices 40 before connector 30 separates. Umbilical cable 34 is attached to the COMM Link 36 and remains with the ordnance.
The pyrofuze arming system 10 provides several novel features not available in current arming systems. The pyrofuze pins 46 allow the release and operation of the arming activation systems for the various ordnance devices used to arm the weapon. The electric current from the initiation circuitry initiates the pyrofuze alloying reaction. The alloying reaction reduces the pyrofuze pins 46 to small molten globules of material which are not capable of physically preventing the activation mechanism from functioning. The ordnance device arming activation system is thus released. By eliminating the arming wires and the arming solenoids from the arming sequence, deficiencies of the prior art are avoided.
The pyrofuze ordnance arming concept of the present invention prevents the inadvertent arming of partially released ordnance. The use of individual separation-detectors 20 and 22 for each weapon surface near each lug 19 prevents the generation of an enable signal until all lugs are free. Hence, the arming of a hung or partially released ordnance is precluded.
Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in the light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described. | A pyrofuze ordnance arming system, for air delivered ordnance, which provs a removable physical barrier to prevent the premature operation of ordnance device arming activation systems. An electrothermally initiated, alloyably removable pyrofuze pin extending from a pyrofuze device is employed as a physical barrier in an arming system to replace the conventional arming wires. The system increases safety and reliability for ordnance arming while decreasing the complexity and labor involved in preparing and loading ordnance on aircraft. | 5 |
[0001] The present invention relates to a vane-type hydraulic camshaft adjuster, including a stator and a rotor situated rotatably in the stator during controlled operation, the rotor and the stator forming at least two working spaces, i.e., working chambers, which are situated between the rotor and the stator and separated by a vane fixed to the rotor, and which are fillable with hydraulic medium (such as oil) from a hydraulic medium supply device (such as an oil pump), at least one locking pin being present, which in the locking state fixes the rotor in a rotatably fixed manner with respect to the stator, the locking pin being connected to an active pressure accumulator which deflects the pin as necessary, and which is preferably separate from the hydraulic medium supply device.
BACKGROUND
[0002] A camshaft adjuster for a camshaft in a motor vehicle, such as a passenger vehicle, a truck. or a similar commercial vehicle, including an internal combustion engine is already known from the prior art, for example from WO 2012/171670 A1.
[0003] Moreover, the present invention relates to a method for locking a rotor of a hydraulic camshaft adjuster relative to a stator of the camshaft adjuster.
[0004] Similar methods are already known from DE 10 2004 048 070 A1. In the cited document, for example a method for operating a hydraulically actuated camshaft adjusting device or a hydraulically actuated device for changing the timing of gas exchange valves of an internal combustion engine of a vehicle is known, the internal combustion engine being controlled or regulated by a vehicle electrical system or vehicle electronics system, and the device including at least one electrically controlled hydraulic valve for influencing the flow of hydraulic fluid via the device, and in addition the at least one valve being acted on by a predefined current (IA) during starting of the internal combustion engine, even before the idling speed is reached.
[0005] Also known from the prior art are center-locking concepts for camshaft adjusters which operate with two pins, i.e., two locking pins. The pins may also be referred to as pegs, bolts, or in general as blocking elements.
SUMMARY OF THE INVENTION
[0006] Previous center-locking concepts or end stop concepts always allow only one defined start position. However, in recent internal combustion engines/motors, various start positions may be necessary, depending on the starting state of the engine, which thus far has not or not easily been possible. While it was known previously only to lock the camshaft adjuster either in a retard position or an advance position or in an intermediate position, namely, the center locking position, the aim now is to be able to achieve at least two, or preferably three, locking positions. A suitable control for this purpose is likewise desirable.
[0007] It is an object of the present invention to depart from a center-locking concept prior to starting in order to set valve timing of the internal combustion engine in such a way that combustion processes according to the Miller principle or the Atkinson principle become possible. According to the Atkinson principle, the intake valve closes very late, while according to the Miller principle it closes very early, namely, during the intake. In both cases, this results in a reduced cylinder charge, and due to the shorter effective compression stroke results in increased efficiency in both cycles. Now, however, an internal combustion engine with such reduced compression is not always startable under all operating conditions. A remedy may now be provided for this situation.
[0008] In particular when the internal combustion engine has not yet reached its operating temperature, i.e., the cooling water has not yet reached between 80° C. and 100° C., good starting capability of the engine should nevertheless be achieved. In addition, the engine should be fireable with only minimal emissions. On the other hand, good starting behavior should also be ensured with start/stop systems, which are currently commonplace.
[0009] Lastly, the aim is to avoid the disadvantages known from the prior art, and to allow a starting operation in the cold state (“key on start”) in use in recent internal combustion engines, which are increasingly being equipped with start/stop automatic systems, for example with preselection of a center locking position, but also during a cold start. Adequate compression should always be provided in the combustion chamber.
[0010] While the ideal start position during an automatic start/stop-start in the warm state requires a start position in the retard position or the advance position, i.e., the corresponding locking position, means should be available to allow an efficient operation in this case. Therefore, not until the start phase of the internal combustion should the best start position be achieved, as a function of the temperature state of the engine.
[0011] Various start positions should thus be preselectable as a function of the state of the internal combustion engine. The aim is to provide a camshaft adjuster which during starting may assume one desired position of at least two locking positions, controlled by the control electronics system of the engine.
[0012] For a generic hydraulic camshaft adjuster, this object is achieved according to the present invention in that the active pressure accumulator is situated below a rotation axis of a camshaft which is connectable to the rotor. The term “below” is understood to mean an arrangement which is defined by gravity.
[0013] It is advantageous when the locking pin and the active pressure accumulator are interrelated with one another in such a way that the locking pin is inhibited from rotatably fixing the rotor relative to the stator.
[0014] It is advantageous when the active pressure accumulator includes a storage space for hydraulic medium, such as oil, which is reducible in size with the aid of a deformable piston, for example, and from which the hydraulic medium is transferable via a pressure medium line into the interior of a rotor, for example through the interior of the camshaft.
[0015] It is also advantageous when an outlet of the storage space, and preferably also the storage space itself, are situated below an outlet of the pressure medium line, for example below a lower edge of the camshaft, in particular in the area of the feed of the hydraulic medium to the camshaft. In this way, the active pressure accumulator may be prevented from running dry, and a rapid start-up of the adjustment kinematics may be forced.
[0016] It is particularly advantageous when not just one locking pin, but, rather, two or even more locking pins are used. It is then unnecessary to decelerate a rotary motion of the rotor relative to the stator during locking, resulting in more precise locking.
[0017] The locking may be efficiently regulated or controlled when the active pressure accumulator is designed in such a way that it is set up to discharge hydraulic medium based on a control signal, such as an electrical signal converted by a switching valve.
[0018] It is also advantageous when the storage space has a volume V 1 which is greater than volume V line of the line section from the outlet of the storage space to the working spaces plus volume V VCP chamber of the working spaces. It is thus ensured that sufficient oil is always present for rotating the rotor relative to the stator or for preventing the locking pin from retracting, even when the internal combustion engine is not running. The oil line between the active pressure accumulator and the adjuster should be preferably short, since an oil volume that is kept small allows quicker filling of the line. During the engine start-up, the line should be separated from the remainder of the lubrication system, for example with the aid of a check valve in the actual supply line.
[0019] It has proven to be particularly advantageous when a central valve is inserted into the rotor, via which hydraulic medium of the active pressure accumulator is suppliable to the working spaces and/or to a link which is designed for accommodating the locking pin. On the one hand, rotation of the rotor may thus be forced, and on the other hand, skipping of a locking position, such as the center locking position, may be achieved by the locking pin(s). A transition from an advance locking position to a retard locking position is thus likewise possible.
[0020] If two locking pins are present which are retractable into a link, for example into a center locking link, a center locking position may be easily fixed by the pins.
[0021] It is also advantageous when, additionally or alternatively, one of these locking pins is retractably supported in a further link, the links being separate from one another. This further link may be a retard locking link or an advance locking link, i.e., may achieve a retard locking position or an advance locking position. The center locking position is also referred to as midlock position (MLP), the position determined by the retard locking position being understood as the retard position. The advance locking position may also be referred to as the advance position.
[0022] To allow good regulation/control capability of the camshaft adjuster, it is advantageous to insert a 5/5-way valve or a 4/3-way valve and a 3/2-way valve between the working spaces and the active pressure accumulator.
[0023] One advantageous exemplary embodiment is characterized in that the rotor is fixable relative to the stator in a rotatably fixed manner in an advance position and/or retard position and/or center position via the locking pins.
[0024] It is advantageous when the rotor is lockable or locked in a rotatably fixed manner in a position on the stator which is rotated at least 5 degrees from the retard position.
[0025] Moreover, the present invention relates to a method for locking a rotor of a hydraulic camshaft adjuster relative to a stator of the camshaft adjuster, the rotor being lockable with respect to the stator in a center position and also in an advance position or retard position via at least one locking pin, and a hydraulic medium of an active pressure accumulator, which is separate from a hydraulic medium supply device provided for filling working chambers between the rotor and the stator, being utilized for influencing a rotary motion of the rotor.
[0026] It is also advantageous when the hydraulic camshaft adjuster according to the present invention is used in such a method.
[0027] In addition, it is advantageous when the hydraulic medium of the active pressure accumulator is utilized for influencing a longitudinal motion of the locking pin and/or for preventing the locking pin or multiple locking pins from retracting into a center locking link.
[0028] In other words, a camshaft adjuster design is provided which allows two or more locking positions, and which provides a strategy in the engine control unit which, with the aid of an active pressure accumulator, allows a change in the position during the engine start-up. Problems with unlocking, which occur with camshaft adjusters which utilize a single conical pin, are prevented. In particular, the use of two locking pins is advantageous here, even though a minimum play always remains. The locking pins may be distributed over the circumference. However, the locking pins should not be situated exactly 180 degrees opposite from one another, since disadvantages arise when the locking play is too great. This is due to the fact that the manufacturing tolerances are additive. Nevertheless, the two locking pins should have at least a certain distance from one another, viewed over the circumference.
[0029] Two locking pins are advantageous which lock axially into a center locking link by spring action when the angle between the rotor and the stator allows this. In this locked-in state, these two locking pins block the movement of the rotor in the direction away from the center position/center locking position.
[0030] One of these two locking pins may also lock into a locking link situated at the late stop of the adjustment range, or alternatively, the other locking pin may lock into a locking link situated at the early stop of the adjustment range.
[0031] The hydraulic medium supply, for example the oil supply, to the center locking link is controlled via a 5/5-way valve. The oil supply to the retard locking link is controlled via a so-called A chamber of the adjuster. Alternatively, this would also be possible for the locking link in the advance position, and the supply could also be provided from a B chamber.
[0032] To allow a change of the locking position either from the center position to the retard/advance position, or from the retard/advance position to the center position, during the start phase when the motor/internal combustion engine is started, the present invention utilizes an active pressure accumulator which is designed in such a way that it may store engine oil, even during a fairly long standstill phase, and is unlocked when the engine is started, so that this stored oil volume allows activation of the unlocking in one position, and the movement toward the other position.
[0033] For controlling the unlocking, movement, and renewed locking operation, a strategy for energizing the actuator, such as a magnet, is possible, as described in greater detail below.
[0034] To ensure that a sufficient oil quantity is retained in the pressure accumulator, the pressure accumulator should be situated below the camshaft axis, and all supply and discharge lines should lead from above to the pressure accumulator to prevent the pressure accumulator from running dry. The volume of the pressure accumulator must be selected in such a way that enough oil remains to fill the working chambers/working spaces (variable camshaft phaser chambers) and their supply channels which have run dry, compensate for leaks, and allow at least one complete adjustment movement. If the active pressure accumulator is present below a supply area of a camshaft adjuster, in particular of a camshaft, seals may be dispensed with, so that when the internal combustion engine is at a standstill the oil does not escape at the same location, and the active pressure accumulator does not run dry.
[0035] In other words, an integration of an active pressure accumulator, which may be switched on and off, into a camshaft adjuster system is provided. When the internal combustion engine/the motor is switched off, the camshaft adjuster is to be moved to the advance position by the control unit strategy. When the internal combustion engine is restarted, the friction of the camshaft drags the camshaft adjuster in the direction of the retard position. Locking now takes place there when the pressure accumulator is not switched on and the locking mechanism has arrived at the center locking position.
[0036] When the pressure accumulator, which is connected to the detent recesses/links for the locking pins/latching pins via channels, is switched on, the oil flowing from the pressure accumulator inhibits the locking pins from locking in the center position. The center position is “overrun,” as the result of which the camshaft adjuster passes completely through, and locks there only at the late stop.
[0037] The connection of the locking pin detent recesses to a “normal” C oil channel may be enabled by a switching valve.
[0038] Lastly, at least two locking positions are assumed by the camshaft adjuster, one of which is a retard locking position. The active pressure accumulator is chargeable by the engine oil system, and may be switched on or off by an electrical control system. A switching valve may be used which may switch the oil flow, which is controlled by the control system of the camshaft adjuster for controlling the locking pin, on and off.
[0039] An electrical camshaft adjuster may be replaced, thereby reducing the costs in relation to the electrical camshaft adjuster by several times. Efficient camshaft adjusters may now be manufactured in large numbers and used in internal combustion engines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The present invention is explained in greater detail below, also with the aid of drawings in which various exemplary embodiments are illustrated.
[0041] FIG. 1 shows the arrangement of an active pressure accumulator in a hydraulic camshaft adjuster according to the present invention, in a longitudinal sectional view;
[0042] FIG. 2 shows the interconnection of a 5/5-way valve which includes two working chambers, which form a pressure chamber that is divided by a vane;
[0043] FIG. 3 shows the interconnection from FIG. 2 , but with the vane arrived in a retard position;
[0044] FIG. 4 shows a volume flow/electrical control current diagram on which the control of the 5/5-way valve, as used in the exemplary embodiment according to FIG. 2 , is based;
[0045] FIG. 5 shows a perspective illustration of a central valve used in the hydraulic camshaft adjuster according to the present invention;
[0046] FIG. 6 shows a hydraulic medium flow rate/electrical control current diagram, similar to the diagram from FIG. 4 , which is used for supplying the central valve from FIG. 5 with oil;
[0047] FIG. 7 shows an overall diagram made up of three partial diagrams for a center locking strategy when the internal combustion engine is stopped, at which point in time locking in the retard position is achieved, and in which a departure is made from the retard locking position for an extended period of time after the internal combustion engine has cooled down, and a center locking position is sought when the engine is restarted;
[0048] FIG. 8 shows an illustration, comparable to FIG. 7 , of an overall diagram, but with the engine not cooled down and a customary start/stop-restart situation present, whereby a center locking position that is achieved when the internal combustion engine is switched off is triggered, and a retard locking position is preselected for starting the engine;
[0049] FIGS. 9 through 12 show the transition from an advance position into a retard locking position, with passing into a center locking position when the engine is started; and
[0050] FIGS. 13 through 16 show the sequence of switching off the engine in an advance position, and transferring the rotor into a center locking position for restarting the internal combustion engine.
DETAILED DESCRIPTION
[0051] The figures are strictly schematic in nature, and are used only for understanding of the present invention. Identical elements are provided with the same reference numerals.
[0052] FIG. 1 illustrates a first specific embodiment of a hydraulic camshaft adjuster 1 according to the present invention. The camshaft adjuster is a vane-type hydraulic camshaft adjuster, i.e., includes a stator 2 and a rotor 3 , between which vanes or pressure chambers 4 are formed. These pressure chambers 4 are not discernible in FIG. 1 . However, one of pressure chambers 4 is discernible in FIGS. 2 and 3 . It is also apparent in FIGS. 2 and 3 that each pressure chamber is divided by a vane 5 which is mounted on rotor 3 in a rotatably fixed manner, thus forming working chambers 6 . One working chamber 6 is referred to as retard working chamber A, and the other is referred to as advance working chamber B. Working chamber 6 may also be referred to as a working space.
[0053] Returning to FIG. 1 , a central valve 7 is screwed into rotor 3 . Central valve 7 is controlled via a central magnet 8 , namely, a proportional magnet. Oil supply channels for working chambers 6 are opened by the control system. Oil may then be transferred into working chambers 6 , or oil may be removed from working chambers 6 , by a pump element, not illustrated, of a hydraulic medium supply device (not illustrated), such as an oil pump. For this purpose, a receiving element such as a tank or an oil pan is also connected.
[0054] However, an active pressure accumulator 9 is also provided here. Pressure accumulator 9 is situated below a camshaft rotation axis 10 . Camshaft rotation axis 10 may also be referred to as “rotation axis” for short.
[0055] Active pressure accumulator 9 includes a piston 11 which is pretensioned via a spring 12 . Spring 12 pretensions piston 11 in the direction of a storage space 13 . Storage space 13 has a volume V 1 . An actuator 14 is provided for unlocking or locking active pressure accumulator 9 . Actuator 14 may also be designed as a switching valve 15 . It may also be designed as a solenoid valve 16 . When energized, actuator 14 effectuates unlocking of piston 11 , which is used for compression.
[0056] A camshaft 17 is provided for connection to rotor 3 in a rotatably fixed manner. A valve 19 is provided at a slide bearing point 18 in order to interrupt an oil supply from the oil pump. A pressure medium line 20 is present for connecting an outlet 21 of storage space 13 to slide bearing point 18 and allowing oil access into the interior of camshaft 17 . The oil from the interior of the camshaft may then penetrate into the interior of central valve 17 , and may reach working chambers A or B through inlets which are opened as necessary. The supply from oil pump P is in particular from the top (but is also possible from other directions), i.e., on the top side of camshaft 17 at the slide bearing or at slide bearing point 18 , while the supply from active pressure accumulator 9 is at the bottom, at slide bearing point 18 .
[0057] Ventilation 22 is also provided to be able to remove air from a spring chamber 23 or to draw air back into the spring chamber when the piston presses oil from pressure accumulator 9 .
[0058] FIG. 2 illustrates the use of a 5/5-way valve 24 . 5/5-way valve 24 includes five inlets/outlets and five positions which the valve may assume during the adjustment. The inlets/outlets lead to hydraulic medium supply device P, a tank T, working chamber A, a center locking link 31 , and working chamber B. The center locking position (MLP) is illustrated in FIG. 2 . A connection 25 between working chamber A and a retard locking link 26 is present. For this purpose, working chamber A has an extra opening area 27 .
[0059] While FIG. 2 illustrates the center locking position, FIG. 3 illustrates the retard locking position. Two locking pins 28 are present. One of the two locking pins 28 is referred to as first locking pin 29 , and the other of the two locking pins 28 is referred to as second locking pin 30 . In the situation in FIG. 2 , both locking pins 29 and 30 are locked into a center locking link 31 . In the state in FIG. 3 , first locking pin 29 is locked into retard locking link 26 , and second locking pin 30 is locked into center locking link 31 . Thus, there is a form fit at the positions of the two links 26 and 31 with locking pins 29 and 30 , respectively.
[0060] FIG. 4 illustrates a flow rate/current diagram, with electric current I plotted on the horizontal axis and hydraulic medium flow rate Q plotted on the vertical axis. At the far left end of the diagram, hydraulic medium supply device P, which is a component that is separate from active pressure accumulator 9 , is connected to working chamber B, whereas working chamber A is connected to the tank. At the far right edge of the diagram, hydraulic medium supply device P is connected to working chamber A, and working chamber B is connected to the tank.
[0061] Five areas 1 , 2 , 3 , 4 , and 5 are discernible in the diagram, and are also illustrated in FIG. 6 . A locking command/a locking instruction is present in areas 1 and 5 . In segments 2 and 4 , no locking is achieved, and in addition no hydraulic clamping of vane 5 is effectuated. However, the hydraulic clamping of vane 5 is forced in an area 3 .
[0062] These areas 1 through 5 are predefined by the switch positions of 5/5-way valve 24 , as illustrated in FIG. 2 .
[0063] A center locking position without locking pins 29 and 30 retracted is effectuated in settings 1 and 5 of 5/5-way valve 24 .
[0064] Separate from 5/5-way valve 24 , a 4/3-way valve in addition to a 3/2-way valve is also possible. A separate valve is thus used for supplying center locking link 31 , which is designed as an elongated hole.
[0065] FIG. 5 illustrates central valve 7 and openings 32 therein. The supply of working chambers A and B, of pressure medium line PP, and of tank T, and the feed from hydraulic medium supply device P, are also indicated. Volume flow rate curve 33 for hydraulic fluid through the working chambers is denoted by reference numeral 33 , whereas the (volume) flow rate curve through channel PP to pressure medium line 20 is provided with reference numeral 34 . The activation of locking pins 28 is thus predefinable as a function of flow rate curve 34 .
[0066] The chronological sequence of the crankshaft speed (uppermost part of the diagram), the pulse duty factor/pulse width modulation state (PWM for short) in the middle part, and the angular position of the camshaft adjuster (phaser position) in the lower area are plotted on the horizontal axis in FIG. 7 . The crankshaft speed is depicted by line 35 . The pulse duty factor is depicted by line 36 . The locking state is depicted by line 37 .
[0067] A state in the locking of a center position MLP, a retard position (Ret.), i.e., late position, and an advance position (Adv.), i.e., early position, is possible. At point in time (t), at which the ignition key is turned and the internal combustion engine is switched off, namely, point in time 38 , the rotational speed of the crankshaft changes. The internal combustion engine is at a standstill at point in time 39 . Current flow is no longer present, i.e., electric current no longer flows, at point in time 40 . Approximately 10 minutes or even eight or more hours after point in time 40 , the ignition key is turned at point in time 41 , and at the same time, oil stored in active pressure accumulator 9 is conveyed into central valve 7 . The unlocking strategy, as already provided, is run through at point in time 42 . The center locking position is reached at point in time 43 , since in this position the two locking pins 29 and 30 are in locking engagement at this point in time.
[0068] Only at point in time 44 does ignition take place. This is the point in time of the so-called “first ignition.”
[0069] FIG. 8 illustrates another state, namely, a state in which less than approximately eight hours time has elapsed between points in time 39 and 41 , at least enough time that the motor or the internal combustion engine has not yet cooled down, and at least has not cooled below 100° C. or 80° C. This is the state of normal start/stop operation.
[0070] FIG. 9 shows an active pressure accumulator 9 , which is connected via pressure medium line 20 (PP) to center locking link 31 in a locking cover 45 . Center locking link 31 is on the other side of a sealing cover 46 , viewed from rotor 3 . Locking pins 29 and 30 are inserted into rotor 3 with pretension via springs 47 and 48 . Vane 5 is in its advance position, so that working chamber A has a maximum size. A switching valve 49 is connected to hydraulic medium supply device P (port C). However, switching valve 49 is in such a position that inflow from P to active pressure accumulator 9 and also to pressure medium line 20 is interrupted. A control unit 50 is used in this regard.
[0071] In FIG. 9 , rotor 3 is in an advance position prior to the engine start-up. In FIG. 10 , the rotor is already in a center position, oil pressure being provided by active pressure accumulator 9 via pressure medium line 20 in link 31 .
[0072] While pressure accumulator 9 is not switched on (i.e., is off) in FIG. 9 , in the state in FIG. 10 it is switched on (i.e., on).
[0073] In the exemplary embodiment of the chronological state according to FIG. 11 , rotor 3 has already arrived at its retard position. Locking link 31 has thus been “overrun.” FIG. 12 illustrates the state in which locking pin 29 is now in locking engagement with locking link 26 .
[0074] In a second variant, rotor 3 is illustrated in FIG. 13 in its advance position prior to the engine start-up. The rotor is once again situated between locking cover 45 and sealing cover 46 . Active pressure accumulator 9 is not yet connected via pressure medium line 20 (PP), and is thus still “off.” Rotor 3 is between its advance position and the center position in the state illustrated in FIG. 14 . However, first pin 29 has already retracted into locking link 31 , and makes locking engagement there. Active pressure accumulator 9 is still “off.” However, as likewise illustrated in FIG. 13 , switching valve 49 is not connected to port C, i.e., pump P. FIG. 15 illustrates the chronologically subsequent state in which second locking pin 30 now also retracts into locking link 31 .
[0075] In FIG. 16 , second locking pin 30 is now also lockingly retracted into link 31 , so that rotor 3 is now locked in its center position by locking pins 28 . Switching valve 49 may also be connected through when, instead of a 5/5-way valve in position 1 , the variant of the 4/3-way valve and 3/2-way valve use, already disclosed, is also desired.
LIST OF REFERENCE NUMERALS
[0000]
1 camshaft adjuster
2 stator
3 rotor
4 vane/pressure chamber
5 vane
6 working chamber (retard working chamber A/advance working chamber B)
7 central valve
8 central magnet
9 active pressure accumulator
10 camshaft rotation axis
11 piston
12 spring
13 storage space
14 actuator
15 switching valve
16 solenoid valve
17 camshaft
18 slide bearing point
19 valve
20 pressure medium line
21 outlet of storage space
22 ventilation
23 spring chamber
24 5/5-way valve
25 connection
26 retard locking link
27 opening area
28 locking pin
29 first locking pin
30 second locking pin
31 center locking link
32 opening
33 volume flow rate curve
34 flow rate curve
35 crankshaft speed
36 pulse duty factor
37 locking state
38 ignition off
39 engine off
40 current off
41 ignition on
42 unlocking strategy
43 MLP reached
44 ignition
45 locking cover
46 sealing cover
47 spring
48 spring
49 switching valve
50 control unit | A hydraulic vane-type camshaft adjuster, having a stator and a rotor arranged therein such that the rotor can rotate during control mode, wherein the rotor and the stator form at least two working chambers and are separated by a vane. A locking pin immobilizes the rotor in a rotationally fixed manner in relation to the stator wherein the locking pin is connected to an active accumulator, which deflects the pin if required. The active accumulator is arranged below a rotation axis on a camshaft. A method is also provided. | 5 |
FIELD OF THE INVENTION
[0001] The present invention pertains to the field of aviation aircrafts and particularly relates to an electrical driven flying saucer based on magnetic suspension.
BACKGROUND OF THE INVENTION
[0002] The lift and thrust of a rotary-wing aircraft are formed by a rotary wing rotating at a high speed. The power for the rotation of the rotary wing comes from an engine. The current rotary-wing aircrafts include all kinds of rotary-wing helicopters. The rotary wing and engine are two separate and independent systems and connected with a transmission mechanism.
[0003] Compared with ordinary rotary-wing aircrafts, the particularity of a rotary-wing flying saucer is that the rotary-wing system and its power system need to be installed inside a saucer shell. The internal space of the saucer shell is limited and restricts the structure and layout of the rotary-wing system and its power system. Therefore, the paramount task for the design of a rotary-wing flying saucer is how to make full use of the limited internal space of the saucer shell and design a rotary-wing system and its power system with a compact structure, reasonable layout, small weight, high motive power conversion efficiency and easy manipulation and control.
[0004] When the rotary wing rotates at a high speed in the saucer shell, due to pneumatic vortex, flexibility of the rotary wing, maneuver of the saucer and other factors, the rotary wing and the saucer shell might collide with each other, resulting in failure and even a serious accident. For more information, please refer to Patent CN 1120008A. There exists the foregoing defect. Therefore, one of the important tasks for the design of a rotary-wing flying saucer is how to avoid the contact and friction between the high-speed rotary wing and the interior of the saucer shell, reduce the noise of the rotary wing during high-speed rotation as well as the vibration of the saucer shell and the saucer cabin, raise motive power conversion efficiency, reduce energy consumption and guarantee the operational safety of the rotary wing and the flying saucer. Similar to ordinary rotary-wing aircrafts, reactive torque will be generated when the rotary wing of a flying saucer rotates. For more information, please refer to Patent CN 1114279A. There is the problem that the body of the flying saucer suffers uncontrollable reactive torque. Therefore, how to overcome the reactive torque of the rotary-wing flying saucer is also another important task for the design of a rotary-wing flying saucer.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is to make full use of the limited internal space of the saucer shell and design and construct a rotary-wing flying saucer which has a compact structure, reasonable layout, small weight, high motive power conversion efficiency and owns an easily manipulated and controlled rotary-wing system and its power system.
[0006] The electrical driven flying saucer based on magnetic suspension provided in the present invention comprises a saucer shell, a saucer cabin, a rotary-wing system and a control system, wherein the rotary-wing system is a magnetic suspension electromotive rotary-wing system and comprises magnetic suspension rotary-wing wheels, an electromotive ring, a magnetic suspension shaft and a magnetic suspension guide rail. The electromotive ring, the magnetic suspension shaft and the magnetic suspension guide rail are fixed to the saucer shell. The magnetic suspension rotary-wing wheels are suspended in the space restricted by the electromotive ring, the magnetic suspension shaft and the magnetic suspension guide rail and go around the magnetic suspension shaft under an electromagnetic thrust.
[0007] The magnetic suspension rotary-wing wheels comprise blades, a magnetic suspension inner ring and a magnetic suspension outer ring. The blades are connected between the magnetic suspension inner ring and the magnetic suspension outer ring along the radial direction (X-X) to form an impeller. The magnetic suspension guide rail includes a magnetic suspension inner ring guide rail and a magnetic suspension outer ring guide rail. The magnetic suspension inner ring guide rail comprises an inner ring upper guideway and an inner ring lower guideway. The magnetic suspension outer ring guide rail comprises an outer ring upper guideway and an outer ring lower guideway. The magnetic suspension inner ring of the magnetic suspension rotary-wing wheels surrounds the magnetic suspension shaft in the radial direction (X-X) and is disposed between the inner ring upper guideway and the inner ring lower guideway in the axial direction (Y-Y). The magnetic suspension outer ring of the magnetic suspension rotary-wing wheels is embedded in the electromotive ring in the radial direction (X-X) and disposed between the outer ring upper guideway and the outer ring lower guideway in the axial direction (Y-Y).
[0008] The magnetic suspension inner ring of the magnetic suspension rotary-wing wheels and the magnetic suspension shaft form a repulsive or attractive magnetic suspension radial bearing in the radial direction (X-X) based on the principle that like magnetic poles repel, but opposite magnetic poles attract, and relying on permanent magnets, electromagnets or superconducting magnets, and make the magnetic suspension rotary-wing wheels suspended on the magnetic suspension shaft in the radial direction (X-X). The magnetic suspension inner ring of the magnetic suspension rotary-wing wheels and the magnetic suspension inner ring guide rail form a repulsive or attractive magnetic suspension axial bearing in the axial direction (Y-Y) based on the principle that like magnetic poles repel, but opposite magnetic poles attract, and relying on permanent magnets, electromagnets or superconducting magnets, and make the magnetic suspension inner ring suspended between the inner ring upper guideway and the inner ring lower guideway. The magnetic suspension outer ring of the magnetic suspension rotary-wing wheels and the magnetic suspension outer ring guide rail form a repulsive or attractive magnetic suspension axial bearing in the axial direction (Y-Y) based on the principle that like magnetic poles repel, but opposite magnetic poles attract, and relying on permanent magnets, electromagnets or superconducting magnets, and make the magnetic suspension outer ring suspended between the outer ring upper guideway and the outer ring lower guideway.
[0009] The magnetic suspension rotary-wing wheels of the rotary-wing system, the electromotive ring and the magnetic suspension shaft constitute a magnetic suspension electric engine. The electromotive ring is a stator, the magnetic suspension rotary-wing wheels constitute a rotor, the magnetic suspension shaft is a spindle, the electromotive ring controls the changes of the current flowing in the electromotive ring according to electromagnetic conversion principle and generates a rotating magnetic field along the ring, and this rotating magnetic field generates a magnetic force upon the magnetic field in the magnetic suspension outer ring of the magnetic suspension rotary-wing wheels and pushes the rotation of the magnetic suspension rotary-wing wheels.
[0010] As an improvement of the present invention, two sets of independent magnetic suspension electromotive rotary-wing systems are superposed and mounted coaxially inside the saucer shell in the axial direction (Y-Y), i.e. the upper rotary-wing system and the lower rotary-wing system. Coaxial axial dual magnetic suspension electromotive rotary wings are formed, wherein the upper rotary-wing system and the lower rotary-wing system rotate in reverse directions, adopt reverse inclination directions of blades, can guarantee the coaxial thrusts in the same direction will overcome or offset the reactive torque generated during rotation of the rotary wings and may realize automatic control for self-rotating angles and self-rotating angular velocity of the flying saucer through controlling the velocities and velocity difference of the upper rotary-wing system and the lower rotary-wing system.
[0011] As an alternative improvement of the present invention, two sets of independent magnetic suspension electromotive rotary-wing systems are superposed and mounted coaxially inside the saucer shell in a radial direction (X-X), i.e. the inner rotary-wing system and the outer rotary-wing system. Coaxial radial dual magnetic suspension electromotive rotary wings are formed, wherein the inner rotary-wing system and the outer rotary-wing system rotate in reverse directions, adopt reverse inclination directions of blades, can guarantee the coaxial thrusts in the same direction will overcome or offset the reactive torque generated during rotation of the rotary wings and may realize automatic control for self-rotating angles and self-rotating angular velocity of the flying saucer through controlling the velocities and velocity difference of the inner rotary-wing system and outer rotary-wing system.
[0012] The magnetic suspension electromotive flying saucer designed in the present invention makes full use of the limited internal space of the saucer shell and has a compact design structure, reasonable layout, small weight and high motive power conversion efficiency. Further, its rotary-wing system and power system can be easily manipulated and controlled. The design of the rotary-wing suspension structure avoids the contact and friction between the high-speed rotary-wing and the interior of the saucer shell, reduce the noise of the rotary wing during high-speed rotation as well as the vibration of the saucer shell and the saucer cabin, raise motive power conversion efficiency, lower energy consumption and guarantee the operational safety of the rotary wing and the flying saucer. The two improvement solutions mentioned in the present invention overcome the problem of reactive torque of the rotary wing under the precondition of meeting the foregoing requirements, and can realize stable and easy power control of the rotary wing.
[0013] The present invention is described below in details in connection with the accompanying drawings and embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 : A side-view sectional schematic of an electrical driven flying saucer based on magnetic suspension;
[0015] FIG. 2 : A top-view schematic of an electrical driven flying saucer based on magnetic suspension;
[0016] FIG. 3 : A side-view sectional schematic of coaxial axial dual electrical driven flying saucer based on magnetic suspensions;
[0017] FIG. 4 : A side-view sectional schematic of coaxial radial dual electrical driven flying saucer based on magnetic suspensions;
[0018] FIG. 5 : A schematic of the radial magnetic suspension structure of a rotary-wing wheel;
[0019] FIG. 6 : A schematic of the axial magnetic suspension structure of a rotary-wing wheel;
[0020] FIG. 7 : A schematic of an embodiment of an electric engine.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Embodiment 1
Single-Rotary-Wing Electrical Driven Flying Saucer Based on Magnetic Suspension
[0021] In reference to FIG. 1 and FIG. 2 , the single-rotary-wing electrical driven flying saucer based on magnetic suspension comprises: a saucer shell 1 , a saucer cabin 2 , a rotary-wing system 3 and a control system 4 , wherein the rotary-wing system 3 is a magnetic suspension electromotive rotary-wing system and comprises magnetic suspension rotary-wing wheels 5 , an electromotive ring 6 , a magnetic suspension shaft 7 and a magnetic suspension guide rail 8 ; the electromotive ring 6 , the magnetic suspension shaft 7 and the magnetic suspension guide rail 8 are fixed to the saucer shell 1 ; the magnetic suspension rotary-wing wheels 5 comprise blades 9 , an magnetic suspension inner ring 10 and a magnetic suspension outer ring 11 , the blades 9 are connected to the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 along the radial direction (X-X) and form an impeller; the magnetic suspension guide rail 8 includes a magnetic suspension inner ring guide rail 12 and a magnetic suspension outer ring guide rail 13 , the magnetic suspension inner ring guide rail 12 comprises an inner ring upper guideway 14 and an inner ring lower guideway 15 , and the magnetic suspension outer ring guide rail 13 comprises an outer ring upper guideway 16 and an outer ring lower guideway 17 ; the magnetic suspension inner ring 10 of the magnetic suspension rotary-wing wheels 5 goes around the magnetic suspension shaft 7 in the radial direction (X-X) and is disposed between the inner ring upper guideway 14 and the inner ring lower guideway 15 in the axial direction (Y-Y); the magnetic suspension outer ring 11 of the magnetic suspension rotary-wing wheels 5 is embedded in the electromotive ring 6 in the radial direction (X-X) and disposed between the outer ring upper guideway 16 and the outer ring lower guideway 17 in the axial direction (Y-Y).
[0022] The magnetic suspension rotary-wing wheels 5 of the electrical driven flying saucer based on magnetic suspension are suspended on the magnetic suspension shaft 7 in the radial direction (X-X) by relying on the magnetic suspension radial bearing formed by the magnetic suspension inner ring 10 and the magnetic suspension shaft 7 ; the magnetic suspension inner ring 10 of the magnetic suspension rotary-wing wheels 5 is suspended between the inner ring upper guideway 14 and the inner ring lower guideway 15 in the axial direction (Y-Y) by relying on the magnetic suspension axial bearing comprising the magnetic suspension inner ring 10 and the magnetic suspension inner ring guide rail 12 ; the magnetic suspension outer ring 11 of the magnetic suspension rotary-wing wheels 5 is suspended between the outer ring upper guideway 16 and the outer ring lower guideway 17 in the axial direction (Y-Y) by relying on the magnetic suspension axial bearing comprising the magnetic suspension outer ring 11 and the magnetic suspension outer ring guide rail 13 .
[0023] The magnetic suspension rotary-wing wheels 5 of the electrical driven flying saucer based on magnetic suspension, the electromotive ring 6 and the magnetic suspension shaft 7 constitute a magnetic suspension electric engine. The electric engine of the electrical driven flying saucer based on magnetic suspension may be designed according to general motor theories, the electromotive ring 6 is a stator, the magnetic suspension rotary-wing wheels 5 constitute a rotor, the magnetic suspension shaft 7 is a spindle, and the structure of an ordinary motor is formed. The electric engine of the electrical driven flying saucer based on magnetic suspension adopts a permanent magnet synchronous engine. Its structure is shown in FIG. 7 .
[0024] The permanent magnet synchronous motor is characterized by a simple and compact structure, low loss, high efficiency and easy manipulation and control. The rotor of a permanent magnet synchronous motor has different structure. For easy description of the principle, this embodiment adopts a simple plug-in structure and pairs of permanent magnets 23 are embedded in the magnetic suspension outer ring 11 to form an exciter field; as a stator, the electromotive ring 6 has a stator core 24 , stator grooves 25 are evenly distributed on the inner circle of the stator core 24 , and 3-phase symmetric stator windings 26 are distributed inside the stator grooves 25 according to a specific rule to form a rotating magnetic field and push the magnetic suspension rotary-wing wheels 5 as a rotor to rotate.
Embodiment 2
Radial Magnetic Suspension Structure of Rotary-Wing Wheels
[0025] An electrical driven flying saucer based on magnetic suspension is provided. Its magnetic suspension rotary-wing wheels 5 are suspended on the magnetic suspension shaft 7 in the radial direction (X-X) according to the magnetic suspension principle.
[0026] As shown in FIG. 5 , a radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 is designed, pairs of magnets 22 are placed on the outer edges of the magnetic suspension inner ring 10 and the magnetic suspension shaft 7 of the magnetic suspension rotary-wing wheels 5 , the N poles of the magnets of the magnetic suspension inner ring 10 face the inside and the S poles face the outside; the S poles of the magnets of the magnetic suspension shaft 7 face the inside and the N poles face the outside. According to the principle that like poles of magnets expel, the N pole of the outer edge of the magnetic suspension inner ring 10 and the N pole of the outer edge of the magnetic suspension shaft 7 form a repulsive force. Therefore, the radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 as shown in FIG. 5 may realize the suspension of the magnetic suspension rotary-wing wheels 5 in the radial direction (X-X) of the flying saucer.
[0027] Magnets 22 may be made from a homogeneous and evenly distributed permanent magnet material. Ideally, the outer edge of the magnetic suspension inner ring 10 and the outer edge of the magnetic suspension shaft 7 are in an equal-distance state. When the magnetic suspension rotary-wing wheels 5 are disturbed, the outer edge of the magnetic suspension inner ring 10 and the outer edge of the magnetic suspension shaft 7 may deviate from the equal-distance position. Nevertheless, as magnetic field intensity decreases with the increase of the distance and increases with the decrease of the distance, the magnetic suspension inner ring 10 and the magnetic suspension shaft 7 will automatically return to the equal-distance position. Obviously, the radial magnetic suspension structure of the permanent magnet rotary-wing wheel is a natural stable structure.
[0028] Alternatively, the magnets 22 may also be made from an electromagnet material. The radial (X-X) suspension structure of the magnetic suspension rotary-wing wheels 5 designed by using electromagnets may realize good controllability, easy implementation of various advanced control strategies and optimal axial (X-X) magnetic suspension effect of the magnetic suspension rotary-wing wheels 5 .
[0029] The magnets of the magnetic suspension inner ring 10 in FIG. 5 may be changed into a superconducting material. When it is in a superconducting state, according to the Meissner effect, the magnetic suspension inner ring 10 will form a repulsive force with the magnetic suspension shaft 7 , thereby realizing superconducting magnetic suspension. By then, if the magnets on the magnetic suspension shaft 7 are permanent magnets, the superconducting magnetic suspension can also obtain a natural stable structure; if the magnets on the magnetic suspension shaft 7 are electromagnets, the superconducting magnetic suspension can also obtain good controllability and may implement various advanced control strategies based on automation theories.
Embodiment 3
Axial Magnetic Suspension Structure of Rotary-Wing Wheels
[0030] An electrical driven flying saucer based on magnetic suspension is provided. Its magnetic suspension rotary-wing wheels 5 are suspended on the magnetic suspension guide rail 8 in the axial direction (Y-Y) according to the magnetic suspension principle, i.e.: the magnetic suspension inner ring 10 is suspended between the inner ring upper guideway 14 and the inner ring lower guideway 15 , and the magnetic suspension outer ring 11 is suspended between the outer ring upper guideway 16 and the outer ring lower guideway 17 .
[0031] As shown in FIG. 6 , an axial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 is designed to make the N poles of the magnets of the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 face upward and the S poles face downward; the S poles of the magnets of the inner ring upper guideway 14 and the outer ring upper guideway 16 face upward and the N poles face downward; the S poles of the magnets of the inner ring lower guideway 15 and the outer ring lower guideway 17 face upward and the N poles face downward. According to the principle that like poles of magnets repel, the N pole at the top of the magnetic suspension inner ring 10 and the N pole at the bottom of the inner ring upper guideway 14 form a repulsive force, and the S pole at the bottom of the magnetic suspension inner ring 10 and the S pole at the top of the inner ring lower guideway 15 form a repulsive force; the N pole at the top of the magnetic suspension outer ring 11 and the N pole at the bottom of the outer ring upper guideway 16 form a repulsive force, and the S pole at the bottom of the magnetic suspension outer ring 11 and the S pole at the top of the outer ring lower guideway 17 form a repulsive force. Therefore, the radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 as shown in FIG. 6 may realize the suspension of the magnetic suspension rotary-wing wheels 5 in the axial direction (Y-Y) of the flying saucer. In the radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 as shown in FIG. 6 , the magnets may adopt a homogenous and evenly distributed permanent magnet material. Considering weight and other factors, the upper and lower guideways of the magnetic suspension guide rail 8 are designed and different magnetic field intensity is selected to make the magnetic suspension ring located in an approximately equal-distance position of the upper guideway and the lower guideway. When the magnetic suspension rotary-wing wheels 5 vibrate up and down under the influence of air current, the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 may deviate from the equal-distance position. However, as magnetic field intensity decreases with the increase of distance and increases with the decrease of distance, the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 will automatically return to the equal-distance position. Thus it may be seen, the axial magnetic suspension structure of the permanent magnet rotary-wing wheels is a natural stable structure. In the radial magnetic suspension structure of the magnetic suspension rotary-wing wheels 5 as shown in FIG. 6 , the magnets may also adopt an electromagnet material. The axial (Y-Y) suspension structure of the magnetic suspension rotary-wing wheels 5 designed with electromagnets may obtain good controllability, easily implement various advanced control strategies and obtain optimal axial (Y-Y) magnetic suspension effect of the magnetic suspension rotary-wing wheels 5 .
[0032] The magnets of the magnetic suspension inner ring 10 and the magnetic suspension outer ring 11 of the magnetic suspension rotary-wing wheels 5 in FIG. 6 may be changed into a superconducting material. When they are in a superconducting state, according to the Meissner effect, the magnetic suspension ring of the magnetic suspension rotary-wing wheels 5 will form a repulsive force with the upper guideway and the lower guideway, thereby realizing magnetic suspension. In this case, if the magnets on the inner magnetic suspension guide rail 12 and the outer magnetic suspension guide rail 13 are permanent magnets, the superconducting magnetic suspension can also obtain a natural stable structure; if the magnets on the inner magnetic suspension guide rail 12 and the outer magnetic suspension guide rail 13 are electromagnets, the superconducting magnetic suspension can also obtain good controllability and various advanced control strategies may be implemented according to the automation theory.
Embodiment 4
Electric Engine
[0033] An electrical driven flying saucer based on magnetic suspension is provided. The magnetic suspension rotary-wing wheel 5 of its rotary-wing system 3 , the electromotive ring 6 and the magnetic suspension shaft 7 constitute a magnetic suspension electric engine. The electric engine of the electrical driven flying saucer based on magnetic suspension may be designed according to the general motor principle, the electromotive ring 6 is a stator, the magnetic suspension rotary-wing wheels 5 constitute a rotor, the magnetic suspension shaft 7 is a spindle and an ordinary motor structure is formed.
[0034] The structure and principle of the electric engine of the electrical driven flying saucer based on magnetic suspension may be same as those of a synchronous motor, an asynchronous motor or a DC motor.
[0035] A typical embodiment of the electric engine of the electrical driven flying saucer based on magnetic suspension is a permanent magnet synchronous engine. Its schematic structure is as shown in FIG. 7 .
[0036] The permanent magnet synchronous motor is characterized by a simple and compact structure, low loss, high efficiency and easy manipulation and control. The rotor of the permanent magnet synchronous motor may have a different structure. For easy description of the principle, this embodiment adopts a simple plug-in structure and pairs of permanent magnets 23 are embedded in the magnetic suspension outer ring 11 to form an exciter field; the electromotive ring 6 as a stator has a stator core 24 , stator grooves 25 are evenly distributed on the inner circle of the stator core 24 , and the 3-phase symmetric stator windings 26 are distributed inside the stator grooves 25 according to a specific rule to form a rotating magnetic field and push the magnetic suspension rotary-wing wheels 5 as a rotor to rotate.
Embodiment 5
Coaxial Axial Dual Magnetic Suspension Electromotive Rotary Wings
[0037] An electrical driven flying saucer based on magnetic suspension adopts coaxial axial dual magnetic suspension electromotive rotary-wing systems when it improves its rotary-wing system to overcome the reactive torque of the rotary wings. The coaxial axial dual magnetic suspension electromotive rotary-wing systems include an upper rotary-wing system 18 and a lower rotary-wing system 19 . The upper and lower rotary-wing systems adopt a same structure and both comprise magnetic suspension rotary-wing wheels 5 , electromotive rings 6 , magnetic suspension shafts 7 and magnetic suspension guide rails 8 .
[0038] During work, the respective electromotive rings of the upper and lower rotary-wing systems generate rotating magnetic fields in reverse directions, which drive respective magnetic suspension rotary-wing wheels to rotate in reverse directions. The upper and lower magnetic suspension rotary-wing wheels maintain a same absolute rotation speed and may offset respective reactive torques and maintain stability of the saucer shell; the upper and lower rotary-wing systems provide lift or forward thrust in the same time and greatly enhance the power performance of the flying saucer.
Embodiment 6
Coaxial Radial Dual Magnetic Suspension Electromotive Rotary Wings
[0039] An electrical driven flying saucer based on magnetic suspension adopts coaxial radial dual magnetic suspension electromotive rotary-wing systems when it improves its rotary-wing system to overcome the reactive torque of the rotary wings. The coaxial radial dual magnetic suspension electromotive rotary-wing systems include an inner rotary-wing system 20 and an outer rotary-wing system 21 . The upper and lower rotary-wing systems adopt a same structure and both comprise magnetic suspension rotary-wing wheels 5 , electromotive rings 6 , magnetic suspension shafts 7 and magnetic suspension guide rails 8 .
[0040] During work, the respective electromotive rings of the inner and outer rotary-wing systems generate rotating magnetic fields in reverse directions, which drive respective magnetic suspension rotary-wing wheels to rotate in reverse directions. The inner and outer magnetic suspension rotary-wing wheels maintain a rated absolute speed difference and may offset respective reactive torques and maintain stability of the saucer shell; the inner and outer rotary-wing systems provide lift or forward thrust in the same time and enhance the power performance of the flying saucer.
[0041] The coaxial radial dual magnetic suspension electromotive rotary-wing systems adopt dual rotary-wing systems placed on a same plane, so the air current disturbance between the two magnetic suspension rotary-wing wheels is reduced significantly and the controllability and stability of the rotary-wing systems are significantly improved. | A magnetic suspension electric rotor flying saucer comprises: a saucer shell ( 1 ), a saucer cabin ( 2 ), a rotor system ( 3 ), and a control system ( 4 ). The rotor wing system is a magnetic suspension electric rotor wing system ( 3 ) composed of a magnetic suspension rotor wing wheel ( 5 ), an electrodynamic ring ( 6 ), a magnetic suspension shaft ( 7 ) and magnetic suspension lead rails ( 8 ). The electrodynamic ring ( 6 ), the magnetic suspension shaft ( 7 ) and the magnetic suspension lead rails ( 8 ) are fixed on the saucer shell ( 1 ). The magnetic suspension rotor wing wheel ( 5 ) is suspended in space limited by the electrodynamic ring ( 6 ), the magnetic suspension shaft ( 7 ) and the magnetic suspension lead rails ( 8 ) and rotates around the magnetic suspension shaft ( 7 ) by the electromagnetic thrust. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a hanger strip for hanging and supporting envelopes in which flat objects can be placed.
2. Description of the Prior Art
U.S. Pat. No. 3,798,810 issued to Brisson et al. on Mar. 26, 1974, shows an article hanging and storage apparatus that has keyhole-like configurations in which hangers for flat objects are supported. The present hanger can be supported in the type of support grooves that are shown in that patent. A type of a file for storing drawings that are supported on clips is shown in U.S. Pat. No. 1,135,310, and stick-on suspension clips that are individually placed onto maps and the like are shown in U.S. Pat. No. 1,387,859.
A flexible document hanging strip that has adhesive supports that adhere along the entire top of the envelope on both sides thereof is shown in U.S. Pat. No. 4,009,784. This device is supported on individual rods that extend perpendicular to the plane of the hanger or strip.
U.S. Pat. No. 3,885,726 shows an office folder that is supported on a hanger rod, and has an opening flap, and U.S. Pat. No. 2,962,335 also shows a storage apparatus that has small tabs that are adhesively secured to flat objects, and which can be supported in a storage cabinet using clips that fit into openings in the tabs.
None of the prior art shows an easily attached continuous hanger strip that provides an edge strip along the open top of an envelope and which has a hinged top portion that normally covers the opening to the envelope and which can be hinged open to provide easy access to the open edge of the envelope without disrupting the attachment to the hanger strip, while completely covering the envelope opening to protect a sheet from outside contaminents while the sheet, such as an art print, is stored.
SUMMARY OF THE INVENTION
The present invention relates to an elognated hanger strip having a surface for adhesively supporting an edge of a sheet or large envelope adjacent the opening to the envelope. The envelope is used for storing flat objects, such as collector art prints, to protect the objects from outside contaminents. The hanger strip has one leg that attaches to one wall of the envelope adacent the opening to the envelope and includes a second leg that forms a flap that can be easily hinged open so that access can be provided to the open edge of the envelope to permit removal and insertion of the flat object. The hanger has a shank with a support which permits it to be supported in slots of a cabinet.
The envelope is formed of two panels that are sealed along three edges, leaving the forth edge open to provide the access opening to the envelope. The one leg of the hanger is attached to one wall of the envelope with suitable adhesive along the entire longitudinal length of the envelope adjacent to the open edge. The second leg of the hanger is hinged to move with the hanger shank and support rib so that in normal position gravity will keep the second leg parallel to the first leg and in position on an opposite side of the envelope from the first leg to provide a sealing type closure over the open edge of the envelope. The second leg can be pivoted away from its position adjacent the side of the envelope and up out of the way so that access can be provided to the top opening of the envelope.
The hanger strip is preferably molded to have hinge sections for pivoting the second leg to open position, and the molded hanger can be made in various colors. The adhesive can be applied in a continuous band along the surface that supports the envelope and will securely hold the envelope in place on the first leg to permit easy use and storage of the envelopes.
The hanger strip is preferably used in connection with a storage cabinet as shown.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side, sectional view of a storage cabinet with hangers made according to the present invention shown installed therein and supporting envelopes in place;
FIG. 2 is a fragmentary end view showing a typical keyhole arrangement for supporting hanger strips of the present invention;
FIG. 3 is a perspective view of the hanger strip of the present invention with the hanger hinged to permit access to an envelope;
FIG. 4 is an end view of the hanger strip of the present invention showing it in its closed position; and
FIG. 5 is an end view of the hanger strip of the present invention showing the strip hinged to permit access to the envelope.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a conventional type cabinet indicated generally at 10 is shown only schematically and with one side wall removed, and includes a top wall 11 and end walls 12 to define an enclosure that has access doors (not shown) at either or both ends 12. These doors will open to permit easy access to the interior. The type of cabinet shown in in U.S. Pat. No. 3,798,810 can be used.
As can be seen in FIG. 2, which is shown from one end 12 with the doors removed or open, a modular hanger strip support member 14 is attached to the interior of the top wall of the cabinet in a suitable manner. The member 14 can be extruded to form generally keyhole-like grooves indicated at 16 and 17, which are arranged in two transverse rows. Above the grooves are suitable index strips 20 that are aligned with each of the grooves, and which can be numbered in a corresponding numbering system to maintain identification of prints that are supported in the grooves. This keyhole-like configuration of the support grooves includes upper head ends 16A and 17A, respectively, which are enlarged from the shank or entrance portions 16B and 17B to form shoulders at the lower edges of the heads 16A and 17A. The support shoulders are used for supporting hanger strips indicated generally at 25 that are slid longitudinally along the support block 14 and when supporting envelopes such as that shown at 26, the envelopes will be supported for their entire length, as shown in FIG. 1.
The hanger strips 25 can be slid in and out of the support slots quite easily. As shown in FIGS. 3, 4 and 5, each of the hanger strips 25 comprises a rib or head member 29, that is supported on a shank 31 of suitable length. The rib or head member 29 has shoulders 29A that engage the shoulders formed by the head portions 16A and 17A of the slots 16 and 17. At the lower end of the shank, at a yoke or junction region 32, there is a widening out of the hanger strip, and a separation into a first elongated, depending support leg 34, and a second leg or flap 35 that is parallel to the first leg and extends downwardly for a short distance. The legs form an inverted, generally U-shape or J-shape and have space 33 between them.
The long leg 34 is divided into an envelope support section 36, which is joined to the upper section by a hinger member 37. The hinge member 37 is formed by extending a different, more flexible plastic in the hinge region. This is done in plastic extrusions at the present time. Also, an intermediate section 38 of the leg is joined with a second hinge section 39 to the yoke portion 32, which joins the legs 34 and 35 and the shank 31. The end of the leg 34 opposite the yoke is the face end of leg 34.
The envelope support section 36 has a coating of a suitable adhesive that is shown by the darkened line on surface 42 so that it will support one of the envelopes 26 along a side surface 43 of the envelope 26. The envelope 26 is made up, preferably, of two thin sheets or panels 27A and 27B of clear plastic, such as MYLAR, that are heat sealed around three edges, including vertical side edges generally shown at 26D and 26E in FIG. 1, and a bottom edge shown generally at 26C. This forms a three-sided envelope made up of two panels having an open top (a top opening) as shown at 44 in FIG. 3. Also, as shown, preferably the envelope support section 36 of leg 34 is spaced downwardly from the top 44 of the envelope 26 along the panel 27A, so that the top opening 44 is adjacent to the yoke 32, and is spaced upwardly from the lower edge or free end 35A of the short leg closing or flap 35. The upper end portions of the two panels or sheets 27A and 27B, which form the envelope 26, thus are unattached from the upper portion 38 of the leg assembly 34. The envelope 26 is positioned in the space 33 between legs 34 and 35. When the hanger strip 25 is in its position as shown in FIG. 4, and in dotted lines in FIG. 5, the upper end portion of the envelope is completely covered by the elongated hanger strip yoke portion 32 and is protected by the leg or flap 35. The envelope cannot open under normal conditions, and contaminents cannot easily enter the envelope. In fact, the legs 34 and 35 will tend to keep the envelope tightly closed because the envelope panels are made of a plastic material has some cohesion to insure that air does not get in to damage an art print, for example, such as that shown in 50 in FIG. 3, which is inside the envelope 26.
Again, it is to be understood that these hanger strips extend for the full length of the envelopes as shown in FIG. 1 and are supported in the member 14 along the full length of the envelope 26.
It should be noted that in manufacturing the hanger strips, the adhesive can be applied and then covered with a release paper of conventional design such as that which is presently used for adhesive layers. The side of the envelope is pressed against the adhesive on surface 42 and is firmly held in place. The upper portion of the envelope adjacent the opening to the envelope is up near the yoke 34. When the short leg or flap 35 is to be moved to position to permit a print to be inserted into the envelope 26, the leg 35 is hinged or pivoted by moving the head 29 in a clockwise direction as shown in FIGS. 3, 4 and 5, and the hinge sections 37 and 39, which also extend the full length of the hanger strips, provide for a pivoting action of the upper section 38 of the first leg 34, to tend to pivot this leg away from the one sheet 27A forming one side of the envelope 26, and also the hinge section 39 permits the yoke 32 and the upper end of the hanger strip, including the shank 31, to pivot about this hinge as well. The leg or flap 35 lifts away from the sheet 27B. The hanger strip upper portion can be pivoted to the position shown in FIGS. 3 and 5, so that the end 35A of the leg 35 is moved clear of the opening 44 to the envelope, and the two sheets 27A and 27B can be separated by moving the sheet 27B away from the sheet 27A and thus away from the long leg 34.
In FIG. 5, the open position of the hanger strip 25 is shown in dotted lines. The leg 35 is shown in dotted lines. The leg 35 is moved so the end 35A is adjacent to leg 37 and between leg 37 and panel 27A of the envelope. The leg 34 will move substantially upright and both panels of the envelope are to the outside of the leg 35.
The opening 44 provides access to the interior of the envelope, as shown in FIG. 3. A print 50 can be inserted or removed with ease. The plastic used for the hanger strip and the hinge area is made to have some memory or set, and once the print has been inserted or removed, the hanger strip can be moved to its original position which seals the upper opening of the envelope 26. The hanger strip can then be replaced in the cabinet with the print intact or moved to other places for storage.
More than one sheet can be stored in the envelopes. For example, a print may be placed between two protective sheets of acid-free paper or other protective sheets, if desired, and the envelopes will expand sufficiently to do that. Also, an envelope made up of three or more panels which are joined together at three edges to make two or more open top pockets in the envelope may be held on leg 34 of the hanger.
The space between the legs 34 and 35 is not excessively large, and preferably the legs will be spaced so that the opening 44 does not remain open, but rather tends to close when the panels are between legs 34 and 35 so that contaminents do not easily get into the envelope.
The under surfaces 29A of the head 29 fit onto the shoulder surfaces formed in the keyhole-like openings or heads 16A and 17A of the grooves 16 and 17 for complete support. Of course, other types of fixed support members can be used for supporting the ribs or heads 29, from the surfaces 29A of the hanger strips. The surfaces 29A can be rounded, rather than flat as shown, if desired. The hanger strips are easily extruded as a unitary plastic part.
If desired, an individual flat panel sheet can be supported by the hanger strip and its upper edge will be protected by flap or leg 35.
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. | A hanger strip for envelopes that contain flat articles such as high quality collector art prints in a storage rack, which has a leg that extends along the top edge of the envelope adjacent the opening to the envelope, and which has a cover flap that can be pivoted open to permit access to the envelope opening. The hanger is at the top edge of the cover flap on a suitable web. The envelope is adhesively secured to the one depending leg so that it can be quickly attached, and then when stored is hung from the hanger to hold the envelope closed completely. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation in part of an application filed on Nov. 9, 1976, Ser. No. 740,222 now abandoned. The parent application was entitled "FLOATING TRIP DIVER," which application was filed in the name of GEORGE B. PAGANI.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fishing tackle device and more particularly a device which will cause a fishing line to submerge, during trolling, to a predetermined depth in order to be in the vicinity of fish located at such depth.
2. Description of the Prior Art
For years it was common practice to place a large sinker made of lead or cast iron on a trip release swivel several yards forward of the hook and bait for the purpose of getting the line down to the desired depth for fishing game fish which would be located at such depth. When the fist took the bait the tension on the leader line would actuate the release causing the heavy sinker to fall so that the fisherman could play the fish in a normal manner. If the weight stayed on the line it would usually tire out the fish and substantially diminish the sporting aspect of the activity. However, due to the comparatively high cost of the weights or sinkers which are lost each time a fish takes the line, a number of devices have been developed which allow the fishing line to be submerged to a desired depth without requiring the loss of a weight or sinker. An example of such a prior art device is shown in U.S. Pat. No. 2,843,966 issued to WAYNE E. INGRAM, et al, on July 22, 1958. When trolling with this device the hydrodynamic forces acting on the fishing line device itself and the leader are such that the horizontal fin assumes a predetermined downward inclination so as to create a negative lift effect as the water impinges upon the upper surface of the horizontal fin causing it to dive to a predetermined depth depending upon the speed of the trolling vessel. However, once a fish takes the bait or lure, the fixed horizontal fin creates a significant impediment to the natural movement of the fishing line and the leader as the fish and angler work in various directions while the line is being reeled in to the vessel. For example, if the fish upon taking the bait heads towards the surface of the water, the horizontal fin will create a good deal of resistance to the movement of the fish applying forces to the leader which could cause it to break. However, the angler is at a disadvantage to determine exactly what steps he should take since the feel of the line varies considerably by virtue of the imposition of the device between the fishing line and the leader. The forces acting on a body of substantial surface area, such as this prior art device, while it is immersed in water and in motion relative to the water, are extremely complex and varied as the fish moves in various directions from side to side, from higher to lower depths and, on occasion, forward of the device. Accordingly, it is very difficult for the fisherman to acquire a "feel" for fishing with such prior art device. Another device which endeavors to mitigate some of the aforementioned hydrodynamic effects is that shown in U.S. Pat. No. 2,976,642 issued to ROBERT J. WICKMAN on Mar. 28, 1961. In this device the horizontal fin is not allowed to remain in the diving attitude once the fish has taken the bait as in the device above. After the fish takes the bait and applies tension to the leader line, a detent mechanism allows the horizontal fin to rotate from a declining or diving attitude to a horizontal or "neutral" attitude. This rotation of the diving fin from a fixed lowered position to a fixed upper position does permit the fisherman to regain feel of the fishing activity with certain game fish which tend to take a course directly away from the fishing vessel and applying maximum tension on the leader line. Fish of this nature basically cause the leader line and the fishing line to come in alignment and thereby cause the horizontal fin to likewise be in substantial alignment so that the feel of the line from the fisherman to the hook is comparatively natural. However, a large number of game fish do not tend to pull directly away from the fishing line but move in directions which reduces the tension between the leader and fishing lines. For example, trout will frequently head straight for the surface of the water in an effort to shake off the hook. In many cases they will actually jump for considerable distances out of the water and sometimes to the extent that the entire leader line and the submerging device clear the water as well. As a fish darts to the surface of the water, an angle is formed between the leader line and the trolling line. The usual reaction of the angler to the reduced tension on the line is to reel in the trolling line. Hence, the lines on both ends of the device are being pulled to the surface with the horizontal fin either oscillating back and forth or presenting a flat surface to the path of travel of the device. This materially changes the normal feel for playing game fish of this nature.
It is an object, therefore, of the present invention to provide a fishing line submerging device which effectively causes the leader line to be placed at the desired depth during trolling but creates a minimum of resistance during the playing or retrieving phase of the fishing activity and, accordingly, minimizing the loss of "feel" of game fishing.
SUMMARY OF THE INVENTION
A preferred embodiment made in accordance with the principles of the present invention utilizes a horizontal fin which is rotatable with respect to a vertical fin at the most forward portion of the horizontal and vertical fins. The horizontal fin, however, is held into a predetermined fixed position while it is in a diving mode but once the fish strikes is released so as to move freely while the fish makes myriad movements in its attempt to shake loose the hook. The free movement of the horizontal vane about a large angle of rotation with respect to the vertical vane closely approximates the normal condition of the fishing line, and the angler is allowed to ply the fish in accordance with substantially normal angling techniques.
In order to more fully describe the various aspects of this invention, the following drawings and descriptions explain the various features and aspects of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the submerging device of the present invention.
FIG. 2 is a plan view of the present invention device.
FIG. 3 is a side view of the fishing line submerging device of the present invention.
FIG. 4 is a sectional view of the detent mechanism taken along line IV--IV of FIG. 2.
FIG. 5 is a horizontal view into a body of water showing the device of the present invention in actual use.
DETAILED DESCRIPTION
Referring by numerals to the accompanying drawings which illustrate a preferred embodiment of the device, in FIG. 1 the fishing line and leader submerging device 10 of the present invention is connected to the fishing line leading to the surface of the water through any one of the perforations 11. The leader line 14 is connected to a rearward portion of the device. The line 14 is connected at its terminal portion 15' to a hook. In order to maintain the vertical fin 21 in a relatively vertical position, it is desirable to have an appropriate means affixed to the device so as to maintain that attitude and, accordingly, the device is shown herein to be provided with a float 23 in the rearward portion 22 of the vertical fin. The vertical fin 21 is hinged at its forward tip 33 to the most forward portion 32 of the horizontal fin.
Referring now to FIG. 2, the hinging relationship between the horizontal fin 31 and the vertical fin 21 is more clearly shown. In this particular embodiment the horizontal fin 31 is provided with a slot 38 in the rearward portions 37 thereof. The rearward edge of the horizontal fin 31 is engaged at slot 38 by the prongs 47 of the detent mechanism 40, said prongs engaging the upper surface 38' and the lower surface 39 of the horizontal fin 31 holding it firmly in position with respect to the vertical fin 21. The detent mechanism 40 is firmly affixed to the vertical fin at the lower rearward portion thereof. The detent mechanism 40 and the vertical fin 21 must be firmly attached either by effective adhesive means or integral construction thereof, since the forces working between the horizontal fin and the vertical fin during trolling is such as to act to move the horizontal fin in a downward direction. The angle formed between the upper surface 38' of the horizontal fin 31 and an imaginary line drawn from eye 45 in the detent mechanism to the perforation 11 where the fishing line 13 is attached to a controlling factor with respect to the depth to which the unit will dive and the forces which will impinge upon the upper surface 38' of the horizontal fin 31. The relationship is such that both the depth of the unit and the forces working across surface 38' are a direct function of said angle. In other words, as the angle increases so does the depth to which the unit will dive and the forces experienced by surface 38'. Hence, as the unit is moving through the water at trolling speeds at depth, the relative motion of the body with the water creates hydrodynamic forces on the respective surfaces 38' and 39 so that less pressure is experienced at surface 39 than at 38' causing and effecting negative lift. This creates considerable downward pressure on the lower prong 47 of the detent mechanism and, in turn, on the cylindrical housing 41 as shown in FIG. 4. This creates substantial tensile forces between the housing 41 and the rearward portion 29 of the vertical fin to which the housing is affixed; accordingly, when a fish strikes the hook on the leader 14, member 42 is pulled rearward against the force of the spring 43 causing the tip 46 to slide within the housing 41 and the prongs 47 to pull clear of the rearward edge of the horizontal fin 31 thereby releasing it from its affixed relationship to the vertical fin. Since the fish will frequently attempt to shake the hook loose by heading to the surface of the water, the horizontal fin 31 will then swing in a downward direction as indicated by arrow A to the position indicated by the dotted lines in FIG. 3. However, the horizontal fin can swing through a large arc considerably in excess of 180°. For example, if the fish decided to head directly upwards and towards the boat, so that the fish and leader would be in close proximity to the trolling line, the rearward portion of the device would be swung nearly 180° in a clockwise direction. This would place the horizontal fin 31 into position of approximately 180° or more away from its original fixed position at the bottom of vertical fin 21. The improved hydrodynamic conditions existing when the horizontal fin is allowed to move freely about a forward hinge point is more clearly shown in FIG. 5. Here the fish is shown heading towards the surface of the water in order to shake loose the hook. The horizontal fin 31 is allowed to assume whatever attitude is necessary to create the minimum hydrodynamic resistance to the leader-troll line system. The horizontal or diving fin 31, in effect, follows the direction of the fish no matter whether it moves up, down, away from or toward the boat. Even if the fish jumps out of the water to a sufficient heighth to cause the diver to clear the water, the horizontal fin upon reentry into the water will automatically adjust to provide the least possible resistance to the leader line. This minimizes the possibility of excessive forces being imposed on the leader line thereby causing it to break. Although the design of the present invention is such that the horizontal fin 31 is free to swing through an arc in excess of 270° or until surface 39 meets with leading edge 15 of the vertical plane, it has been found that freedom of movement in an arc of 180° is usually sufficient for most gaming purposes. Accordingly, to avoid entanglement of the horizontal fin with the trolling line or to cause the horizontal fin to be inadvertently caught in an upward position and thereby creating resistance while the line is being pulled inward, it has been found that appropriate stopping mechanisms can be used to limit the swing to approximately 180°. For example, a small protrusion can be extended beyond the tip 33 so as to engage the forward portion of surface 39 as it swings up to the 180° point thereby inhibiting further arcuate movement.
Appropriate means for connecting the troll line and the leader line to the device are conventional swivels 16. Numerous variations may be employed in the construction of the device of the present invention. For example, an alternative design would be to avoid the slot 38 in the horizontal fin 31 and simply have the detent mechanism engage the horizontal fin 31 at a rearward edge thereof as it swings flat against lower edge 25 of the vertical fin 21.
From the foregoing description, it will be readily seen that there has been produced such a fishing line submerging device as substantially fulfills the object of the invention as set forth herein.
While the specification sets forth in detail the present and preferred construction of the fishing line submerging device, in actual practice deviations from such detail may be resorted to without departing from the spirit of the invention, as defined in the appended claims. | A fishing line submerging device having a diving fin which will cause the device to run at a selected depth but which fin releases, upon a strike by the fish, to present a minimum of hydrodynamic resistance to the fishing line, regardless of whether the line is being reeled in or played out during the course of bringing the fish in. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional application No. 61/465,171 filed Mar. 14, 2011, titled ROOFTOP CENTRALIZED CONCENTRATED SOLAR POWER COLLECTION SYSTEM; U.S. Provisional application No. 61/465,165 filed Mar. 14, 2011, titled APPARATUS AND METHOD FOR POINTING LIGHT SOURCES; and U.S. Provisional application No. 61/465,216 filed Mar. 16, 2011, titled TIP-TILT TRACKER, each of which is incorporated herein by reference in its respective entirety for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to control systems that use diffraction information to help aim light redirecting elements at desired target(s). More specifically, these strategies are used to controllably aim heliostats in the field of concentrating solar power (CSP).
BACKGROUND OF THE INVENTION
[0003] The use of heliostats in the field of concentrating solar power (CSP) is well established in the prior art. A typical CSP system includes at least one centralized tower and a plurality of heliostats corresponding to each centralized tower. The tower is centralized in the sense that the tower serves as the focal point onto which a corresponding plurality of heliostats collectively redirect and concentrate sunlight onto a target (also referred to as a focus or a receiver) associated with the tower. The concentration of sunlight at the tower receiver is therefore directly related to the number of heliostats associated with the tower up to certain fundamental limits. This approach concentrates solar energy to very high levels, e.g., on the order of 1000× or more if desired. In practical application, many systems concentrate sunlight in a range from 50× to 5000×. The high concentration of solar energy is converted by the tower into other useful forms of energy. One mode of practice converts the concentrated solar energy into heat to be used either directly or indirectly, such as by generating steam, to power electrical generators, industrial equipment, or the like. In other modes of practice, the concentrated solar energy is converted directly into electricity through the use of any number of photovoltaic devices, also referred to as solar cells.
[0004] Heliostats generally include a mirror or other suitable optical device to redirect sunlight, support structure to hold the mirror and to allow the mirror to be articulated, and actuators such as motors to effect the articulation. At a minimum, heliostats must provide two degrees of rotational freedom in order to redirect sunlight onto a fixed tower focus point. Heliostat mirrors are may be planar, but could possibly have more complex shapes. Heliostat articulation can follow an azimuth/elevation scheme by which the mirror rotates about an axis perpendicular to the earth's surface for the azimuth and then rotates about an elevation axis that is parallel to the earth's surface. The elevation axis is coupled to the azimuth rotation such that the direction of the elevation is a function of the azimuth angle. Alternatively, heliostats can articulate using a tip/tilt scheme in which the mirror rotates about a fixed tip axis that is parallel to the earth's surface and a further tilt axis. The tip axis often is orthogonal to the tilt axis but its axis of rotation tips as a function of the tip axis rotation. The tilt axis is parallel to the earth's surface when the heliostat mirror normal vector is parallel to the normal vector of the earth's surface.
[0005] Heliostats are pointed so that the reflected sunlight impinges on the central tower receiver, which often is fixed in space relative to the heliostat. Because the sun moves relative to the heliostat site during the day, the heliostat reflectors must track the sun appropriately to keep the reflected light aimed at the receiver as the sun moves.
[0006] FIG. 1 schematically illustrates a typical CSP system 403 . CSP system 403 has tower 405 with focus region 407 and a plurality of corresponding heliostats 409 (only one of which is shown for purposes of illustration) that aim reflected sunlight at region 407 . Sunlight represented by vector 411 reflects off the heliostat mirror 413 oriented with surface normal represented by vector 415 . Mirror 413 is accurately aimed so that reflected sunlight according to vector 417 is aimed at focus 407 generally along heliostat focus vector 419 , which is the line of sight from the heliostat mirror 413 and the tower focus 407 . If mirror 413 were to be aimed improperly so that vector 417 is not aimed at focus 407 , these two vectors would diverge. Consequently, the reflected light 417 impinges on the tower focus 407 . For such conditions to be realized, the laws of reflection require that the angle formed between the sunlight vector 411 and mirror normal 415 must be equal to the angle formed between vector 419 and mirror normal 415 . Further, all three vectors 411 , 415 , and 419 must lie on the same plane. It can be shown using vector algebra that given a sunlight vector 411 and focus vector 419 , there is a unique solution for mirror normal 415 that is simply the normalized average of vectors 411 and 419 .
[0007] Many control strategies use open loop control, closed loop control, or combinations of these. Many heliostat control systems employ open loop algorithms based on system geometry and sun position calculators in order to determine the sun and heliostat-focus vectors as a function of time. These calculations result in azimuth/elevation or tip/tilt commands to each heliostat device. Such control systems generally assume that the location of the heliostats are static and well defined and/or otherwise rely on periodic calibration maintenance to correct for settling and other lifetime induced drifts and offsets. Open loop solutions are advantageous in that they do not require any feedback sensors to detect how well each heliostat is pointed. These systems simply tell every heliostat how to point and assume that the heliostats point correctly. A major drawback is that open loop systems demand components made with high precision if accuracy is to be realized. Incorporating precision into the system components is very expensive. Additionally, it can be cost prohibitive to perform the precise surveying needed to perform open loop calculations with sufficient accuracy. The expense of precision and surveying escalates as the number of heliostats in a heliostat field increases. Consequently, systems that rely only on open loop control tend to be too expensive.
[0008] Closed loop heliostat control relies on feedback from one or more sensors capable of measuring differences, or errors, between the desired condition and an actual condition. These errors are then processed into compensation signals to heliostat actuators to articulate the mirrors so that reflected sunlight impinges on the tower focus. Closed loop pointing has an advantage that it does not require precise components or installation or knowledge of the system geometry. The system also can be made less sensitive to lifetime drifts. Less demand for precision means that these systems are much less expensive than systems that rely solely on open loop control. These advantages become more important for smaller scale, commercial rooftop CSP applications. Such installations cannot provide sufficiently stable mounting surfaces because of weight load limitations to maintain accurate open loop control over time without increased maintenance demands. Consequently it is highly desirable that such small scale commercial rooftop installations track the sun using at least some degree of closed loop techniques in order to be cost effective and otherwise practical. Closed loop systems offer the potential to use control software rather than predominantly precision, and control is much less expensive to implement than precision.
[0009] A difficulty in applying closed loop pointing methods on CSP systems is that the pointing condition requires the bisection of two vectors rather than alignment to a single vector. This is challenging, because there is no optical signal available at the nominal aim point (i.e., mirror normal 415 in FIG. 1 ). CSP system designers have contemplated that an ideal location for a feedback sensor would be to place the sensor in the path of the reflected beam, such as at the tower focus 407 . Unfortunately, this is not feasible because no practical sensor could withstand the extreme temperatures or the UV dosage that result from highly concentrated sunlight. This poses a significant technical challenge of how to track and correct the aim of a beam if the beam cannot be tracked. Consequently, there remains a strong need for techniques that would allow closed loop pointing to be feasible.
SUMMARY OF THE INVENTION
[0010] The present invention relates to apparatus and methods to provide a closed loop pointing system for the purpose of redirecting light from a source onto a target. Whereas the principles of the invention disclosed herein are presented in the context of concentrating solar power, the apparatus and methods are generally applicable to any pointing system in which light is redirected onto one or more fixed and/or moving targets.
[0011] The present invention appreciates that the diffraction pattern for light that is both diffracted and redirected by a heliostat is a function of how the light redirecting element is aimed. This means that the aim of the light redirecting element can be precisely determined once the aim of the diffracted light is known. Advantageously, the characteristics of diffracted light indicative of how the diffracted light is aimed can be determined from locations outside the zone of concentrated illumination in which sensors are at undue risk. This, in turn, means that diffracted light characteristics can be detected at a safe location, and this information can then be used to help precisely aim the light redirecting element onto the desired target, such as a receiver in a CSP system. The aim of the diffracted light is thus an accurate proxy for the light beam to be aimed at the receiver.
[0012] Advantageously, one or more centralized sensors can be used to aim multiple light redirecting elements. This means that common sensor(s) can detect diffraction characteristics of multiple heliostats. This facilitates incredibly simple implementation of the control system in large or small heliostat arrays in which the array is deployed over a large or small area.
[0013] The system is extremely accurate. For example, the sun diameter generally spans about ½ degree of the sky. In more preferred embodiments, the pointing control system of the invention may provide accuracy of at least 1/20 th of a degree so that the sun, not the system, is the limiting factor on accuracy.
[0014] Diffracted light has different characteristics that are a function of how the light redirecting element is aimed. These include wavelength (color or frequency), intensity, diffraction orders, combinations of these, and the like. The present invention may detect and use one or more of these diffraction characteristics to aim light redirecting elements using closed loop control. In utility-scale CSP installations, control systems that comprise closed loop strategies advantageously facilitate cost-effective deployment of a large number of small heliostats. Such an architecture would otherwise be cost-prohibitive if each individual heliostat were to require careful installation, alignment, and calibration. Embodiments of the invention that use smaller heliostats are advantageously easier to handle and install, resulting in further cost reduction.
[0015] In preferred modes of practice, the present invention teaches that a portion of the incident light impinging on a light redirecting element can be diffracted into one or more diffraction orders. The diffracted light furthermore can be detected by suitable sensor(s) such as an imaging system proximal to the receiver target (nominal target location) but sufficiently spaced from the nominal target so the sensor(s) are outside a zone of concentrated illumination associated with undue risk of sensor damage. The detected property(ies) of the diffracted light, including wavelength and intensity, can be used by the control system to determine if the light redirecting element is oriented such that the non-diffracted, redirected light substantially impinges on the nominal target. Furthermore, the control system uses the detected diffraction information, such as wavelength and intensity information to know how to articulate and correct the aim of the light redirecting element when the redirected light does not substantially impinge on the target location.
[0016] The present invention teaches that a portion of the incident light impinging on a light redirecting element can be diffracted using a variety of different techniques. For example, a portion of the incident light can be diffracted using one or more diffraction gratings. Diffraction gratings are well known in the field of spectroscopy for their ability to split light into its constituent wavelengths or colors. While linear (one-dimensional) gratings may be used in the practice of the present invention, they are less preferred; the present invention teaches that intrinsically two-dimensional structures, such as circular (incorporating concentric rings) or spiral (incorporating single or multiple spiral features) gratings, are particularly advantageous for heliostat tracking. Such structures are capable of diffracting in two dimensions, thusly broadcasting light broadly into three dimensions.
[0017] Gratings can have uniform spacing between features or may have spacing variations as a function of location on the grating. Both the orientation and spacing of the grating lines affect the diffractive properties of the grating, allowing gratings to be tuned for specific applications.
[0018] While standard linear gratings can be used by the present invention, individual linear gratings provide more limited utility compared to 2-D gratings. By way of example, when used to sense pointing of the sun, in the non-dispersing direction, a single linear grating broadcasts light over only a very narrow angle of slightly less than ½ degree (the width of the sun.) Two linear gratings may be provided, oriented ½-degree differently from one another, to provide a 1-degree broadcast angle. Similarly, four linear gratings may be provided to provide a 2-degree broadcast angle, and so on.
[0019] Since many practical applications require broadcast angles of 90 to 360 degrees, a large number of linear gratings may be required to provide a sufficient broadcast angle. For this reason, two-dimensional gratings such as circular or spiral are preferred by the present invention.
[0020] In other embodiments, the present invention teaches that a portion of the incident light impinging on a light redirecting element can be diffracted using one or more diffractive elements in the form of an embossed or otherwise fabricated sheet (including a laminated sheet) incorporating one or more diffraction gratings, wherein the sheet in some modes of practice has been manufactured using techniques similar to those used to fabricate holographic stickers commonly used in commercial applications for security and authenticity validation. In some embodiments, the sheets may have diffraction features incorporated into two or more sub-elements. For instance, such a sheet may comprise an array comprising a plurality of spiral or circular diffraction gratings. Such manufacturing techniques easily implement diffractive optics and can produce complex diffraction patterns inexpensively compared to scientific-grade diffraction gratings. Sheets made using the techniques used to manufacture holographic stickers can be readily mass produced and can provide cost effective diffractive elements in the systems disclosed herein.
[0021] The present invention teaches that diffractive elements may be used with either reflective and/or transmissive light redirecting elements. In the case of reflective light redirecting elements, incident light hitting the diffractive element also is partially reflected by the diffractive element according to the laws of reflection. The pattern of the resultant diffractive orders is produced and positioned in a manner that correlates accurately relative to the vector of the reflected rays to be aimed at the desired target(s). Such reflected rays are also referred to herein as the 0 th diffraction order.
[0022] In the case of transmissive light redirecting elements, incident light is refracted and diffracted by the diffractive element and refracted or otherwise altered by the light redirecting element. An exemplary refractive light redirecting element is a refractive type optic such as a lens.
[0023] The present invention teaches that multiple diffractive elements may be used. Each diffractive element may be used to produce different diffractive properties with respect to a particular light redirecting element. This can be done for the purpose of extending the dynamic range of the feedback system and/or to eliminate ambiguities related to symmetries, such as positive and negative diffractive orders and multiple axes of rotation.
[0024] The present invention teaches that a single diffractive element may be used with respect to a particular light redirecting element, wherein the diffractive element incorporates multiple sub elements. This also can provide different diffractive properties for the purpose of extending the dynamic range of the feedback system and/or to eliminate ambiguities related to symmetries, such as positive and negative diffractive orders and multiple axes of rotation.
[0025] The present invention teaches that the detection features used to detect diffraction characteristics may be in the form of an imaging system proximal to the receiver target but at a safe distance so that the detection features avoid undue exposure risk to the concentrated light. The imaging system may include a plurality of imaging devices such as cameras and more specifically digital cameras capable of spatially and spectrally resolving diffractive elements mechanically coupled to light redirecting elements. The field of view of each imaging device is preferably fixed. Alternatively, the field of view may be adjustable via actuation capabilities such as pan and tilt actuation and/or zoom functionality. Similarly the total net field of view of a particular imaging device may include the entire set of diffractive elements in the system or a subset therein. Regardless of the field of view constraints of a given imaging device, the imaging system as a whole desirably has a field of view that together sufficiently covers the diffractive elements used for aiming control.
[0026] In one aspect, the present invention relates to a method of concentrating sunlight, comprising the steps of:
a) redirecting and diffracting sunlight; and b) observing the diffracted sunlight; and c) using the observed diffracted sunlight in a closed loop control system to controllably actuate a plurality of light redirecting elements in a manner that concentrates the sunlight onto at least one target.
[0030] In another aspect, the present invention relates to a method of aiming re-directed sunlight, comprising the step of using a diffraction characteristic of the sunlight to aim the sunlight onto a target.
[0031] In another aspect, the present invention relates to a system for concentrating sunlight onto a centralized target, comprising:
a) a plurality of heliostats, each heliostat comprising:
i. a redirecting element that redirects incident sunlight; ii. a diffractive element that diffracts incident sunlight, wherein a characteristic of the diffracted sunlight is indicative of the orientation of sunlight redirected by the redirecting element;
b) a device that observes the diffractive element; and c) a control system that uses observed diffracted light to determine a compensation that articulates the redirecting elements to concentrate the redirected sunlight onto the centralized target.
[0037] In another aspect, the present invention relates to a heliostat that redirects sunlight, comprising:
a) a redirecting element that redirects incident sunlight; and b) a diffractive element that diffracts a portion of the sunlight incident on the heliostat, said diffractive element coupled to the redirecting element such that a characteristic of the diffracted sunlight is indicative of the orientation of sunlight redirected by the redirecting element.
[0040] In another aspect, the present invention relates to a heliostat system for concentrating sunlight onto a target, comprising:
a) a plurality of heliostats that redirect, diffract, and concentrate sunlight onto the first centralized target; each heliostat comprising:
i. a redirecting element that redirects incident light onto the centralized target; and ii. at least one diffractive element provided on the redirecting element;
b) an imaging device comprising a field of view that observes the diffractive element; and c) a control system that uses a characteristic of the observed diffractive element to determine a compensation that articulates the redirecting elements to concentrate the redirected sunlight onto the centralized target.
[0046] In another aspect, the present invention relates to a closed loop pointing system that controls the pointing of a plurality of heliostats to concentrate light onto a centralized target, comprising:
a) a plurality of heliostats that diffract and redirect sunlight that is incident on the heliostats; and b) a control system that uses the diffracted sunlight to control the articulation of the heliostats so that the redirected sunlight is concentrated onto the centralized target.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 is a simplified perspective view of an exemplary concentrating solar power system;
[0050] FIG. 2A is a perspective view of an exemplary embodiment of the present invention applied to a concentrating solar power system;
[0051] FIG. 2B is a perspective view of an exemplary imaging subsystem of the present invention applied to a concentrating solar power system;
[0052] FIG. 2C is a perspective view of an exemplary heliostat with an exemplary diffractive element of the present invention;
[0053] FIG. 3 is a perspective view of an exemplary heliostat;
[0054] FIGS. 4A through 4D schematically show front views of exemplary reflective elements fitted with exemplary diffractive elements of the present invention;
[0055] FIG. 5 schematically shows a front view of a linear diffraction grating;
[0056] FIG. 6A is a side view of the linear diffraction grating of FIG. 5 illuminated by an on axis light ray;
[0057] FIG. 6B is a side view of the linear diffraction grating of FIG. 5 illuminated by an off axis light ray that is orthogonal to the diffraction lines;
[0058] FIG. 7A-C is a front view of exemplary diffractive element including concentric or spiral diffraction lines;
[0059] FIG. 8A is a front view of an exemplary diffractive element including a plurality of concentric or spiral diffraction lines;
[0060] FIG. 8B is a front view illustration of observed spectra of an exemplary diffractive element;
[0061] FIG. 9A-C is a perspective view of exemplary layered diffractive elements;
[0062] FIG. 10 a shows a perspective view of an exemplary imaging device;
[0063] FIG. 10 b shows an exploded perspective view of the imaging device of FIG. 10 a;
[0064] FIG. 11 is a schematic diagram of an exemplary tracking control system incorporating an imaging subsystem;
[0065] FIG. 12 a is a schematic diagram of an exemplary imaging subsystem;
[0066] FIG. 12 b is a schematic diagram of an exemplary imaging subsystem;
[0067] FIG. 13 a is a schematic diagram of an exemplary articulation subsystem;
[0068] FIG. 13 b is a schematic diagram of an exemplary articulation subsystem;
[0069] FIG. 14A-B is a schematic diagram of an exemplary computation subsystem;
[0070] FIG. 15 is a schematic diagram of an alternate exemplary computation subsystem;
[0071] FIG. 16A-C is an exemplary 2D ray trace of a diffractive element;
[0072] FIG. 17 is an exemplary perspective ray trace of a diffractive element;
[0073] FIG. 18 is an exemplary perspective ray trace of a diffractive element from two viewpoints;
[0074] FIG. 19 is an exemplary perspective ray trace of a diffractive element from two viewpoints;
[0075] FIG. 20 is an exemplary perspective ray trace of a diffractive element from two viewpoints;
[0076] FIG. 21 is an exemplary perspective ray trace of a diffractive element from three viewpoints;
[0077] FIG. 22 is an exemplary tracking system with a single target;
[0078] FIG. 23 is an exemplary tracking system with a plurality of targets and
[0079] FIG. 24 is an exemplary tracking system with a plurality of targets.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0080] The apparatus and methods presented herein describe closed loop tracking systems that use diffractive properties of light to sense orientation and effect articulation of a plurality of light redirecting elements in a preferred manner. Embodiments described herein are exemplary and do not represent all possible embodiments of the principles taught by the present invention. In particular, embodiments of the present invention have direct application in the field of concentrating solar power, particularly concentrating solar power including the use of heliostats to redirect sunlight onto a fixed focus in which concentrated sunlight may be converted into other forms of energy such as heat or electrical energy. Nevertheless, the apparatus and methods described herein can be applied and adapted by those skilled in the art for use in alternative applications in which light from a source must be redirected onto a plurality of targets, particularly light from a source that is not stationary.
[0081] FIGS. 2A-2C and 3 show an exemplary CSP system 1 incorporating principles of the present invention that is deployed for purposes of illustration on mounting surface 21 , which may be a roof of a building in some embodiments. CSP system 1 includes an array of heliostats 9 that redirect and concentrate sunlight onto focus area 7 of tower 5 . An imaging subsystem 11 is mounted to tower 5 to detect diffraction information produced by heliostats 9 .
[0082] A control system (not shown) uses the detected diffraction information in a closed loop control system to articulate and thereby aim redirected sunlight from the heliostats 9 onto focus area 7 . The control system desirably includes a plurality of computational devices (not shown) coupled electronically to imaging subsystem 11 and heliostats 9 . The control system includes software to process diffraction information acquired by imaging subsystem 11 in order to effect articulation of the plurality of heliostats 9 for the purpose of controllably redirecting sunlight onto the system focus area 7 .
[0083] Each heliostat 9 generally includes diffractive element 23 , a light redirecting element in the form of reflecting element 25 , and a support structure including pivot mechanisms 27 and 31 , mechanical support 33 , and base 35 . The diffractive element 23 and its associated reflecting element 25 form an assembly that articulates so that the assembly can track the sun and aim redirected sunlight onto the focus area of tower 5 . Diffractive element 23 is coupled to reflecting element 25 so that the diffraction information produced from the diffractive element 25 can be used to controllably aim light redirecting element 25 via aiming strategies comprising closed loop control techniques optionally in combination with other control strategies, e.g, open loop control and/or feedforward techniques. In particular, imaging subsystem 11 detects diffraction information produced by diffractive element 23 . The information correlates to the manner in which reflecting element 25 is aimed. Accordingly, the information can be used to articulate reflecting element 25 in a manner effective to correct and/or maintain the aim of redirected light onto focus area 7 .
[0084] Pivot mechanism 31 is mechanically coupled to support structure 34 and incorporates tip axis 33 such that tip axis 33 is fixed relative to the orientation of the support structure 34 . Pivot mechanism 27 is pivotably coupled to pivot mechanism 31 and can be actuated to pivot on tip axis 33 . Pivot mechanism 27 incorporates tilt axis 29 such that tilt axis 29 has an orientation that is a function of the rotation of pivot mechanism 31 about the tip axis 33 . Reflecting element 25 is pivotably coupled to pivot mechanism 27 and can be actuated to pivot on tilt axis 29 . Pivot mechanisms 27 and 31 provide two degrees of rotational freedom about axes 29 and 33 , respectively, for articulating the reflecting element 25 and diffractive element 23 . The orientation and position of reflecting element 25 and diffractive element 23 are thereby affected by both rotational degrees of freedom provided by tip axis 33 and tilt axis 29 . In the embodiment shown tilt axis 29 and tip axis 33 are substantially orthogonal to each other but do not lie on the same plane. Articulation of the components around axes 29 and 33 allows the reflecting element 25 to be controllably aimed at focus area 7 .
[0085] The embodiment of heliostat 9 shown in FIGS. 2A-2C and 3 incorporates two rotational degrees of freedom for articulating the diffractive element 23 and reflecting element 25 . In an alternative embodiment, the orientation and position of the diffractive element 23 and reflecting element 25 may be affected by zero or more rotational degrees of freedom and one or more translational degrees of freedom. In yet another alternative embodiment, the orientation and position of the diffractive element 23 and reflecting element 25 may be affected by one or more rotational degrees of freedom and zero or more translational degrees of freedom.
[0086] Diffractive element 23 preferably is located on reflective element 25 in such a manner that diffractive element 23 can be observed by imaging subsystem 11 irrespective of orientation of reflective element 25 over the functional articulation range of heliostat 9 . For purposes of illustration, FIG. 2 c shows diffractive element 23 centrally located along a top edge of reflecting element 25 . Other positioning strategies may be used such as those described below with respect to FIGS. 4A-4D .
[0087] In addition to the functional articulation range of individual heliostat devices 9 , the ability to observe diffraction element 23 by imaging subsystem 11 is affected by the position and orientation of the heliostats 9 relative to the imaging subsystem 11 and the proximity of heliostats 9 to one another. Consequently it is possible in some embodiments that portions of reflecting element 25 might be obstructed by one or more other reflecting elements 25 of other heliostats 9 from the viewpoint of the imaging subsystem 11 . Because of this, in some embodiments there may be regions on reflective surface 25 where it is not practical to locate diffractive element 23 .
[0088] Diffractive element 23 preferably has a sufficient size such that diffractive element 23 can be resolved by imaging subsystem 11 over the functional articulation range of heliostat 9 . At the same time, it is also preferable to minimize the area of diffractive element or elements 23 such that these occupy a small fraction of the total area of reflecting element 25 . This is particularly true in the case of a concentrating solar power system in which efficiency is affected by the net reflecting area of the heliostat 9 . Consequently the minimum size of diffractive element 23 is dependent on the resolution of imaging subsystem 11 , and the location of the diffractive element 23 relative to the imaging subsystem 11 . As a limiting factor, the minimum area of diffractive element 23 is determined by the resolution of the imaging subsystem 11 and the location of the most distant heliostat 9 in the system 3 .
[0089] In one embodiment of tracking control system 1 , all diffractive elements 23 among the heliostats 9 or a particular subset of heliostats 9 have areas that are substantially uniform in magnitude. Having all diffractive elements substantially uniform in size advantageously reduces manufacturing complexity and requires less specificity when installing heliostats 9 to ensure that heliostats 9 are located properly relative to imaging subsystem 11 . A disadvantage of this embodiment is that the amount of power that could be generated by a given CSP system is not maximized, as some of the diffractive elements 23 will be larger than needed to ensure that all the elements 23 in the array can be resolved by the imaging subsystem 11 regardless of distance from subsystem 11 .
[0090] An alternative embodiment incorporates diffractive elements 23 having a plurality of sizes such that the area of diffractive elements 23 is correlated, e.g., inversely proportional, to their distance from imaging subsystem 11 . The embodiment has an advantage in that it can be designed so that the effective area of diffractive elements 23 in the image space of imaging subsystem 11 is substantially uniform. Additionally this embodiment increases the total throughput of a CSP system by minimizing parasitic losses from diffractive elements 23 that are too large with respect to some heliostats 9 . The major disadvantage to this embodiment is in increased manufacturing and installation complexity.
[0091] The shape of diffractive element 23 as shown is substantially square, but a variety of shapes may be used. In alternative embodiments the shape of diffractive element 23 may have a substantially rectangular shape. In yet another alternative embodiment the shape of diffractive elements 23 may be substantially circular. In still another alternative embodiment the shape of diffractive element 23 may have a freeform outline. Furthermore embodiments of the present invention may include diffractive elements 23 having a plurality of shapes.
[0092] Imaging subsystem 11 is used to detect or otherwise capture diffraction information produced by diffractive elements 23 . The subsystem 11 is able to detect, sense, observe, or otherwise capture diffraction information including but not limited to intensity and color of light reflected, scattered, or diffracted by diffractive elements 23 . The diffraction information correlates to the aim of reflecting elements 25 , and therefore can be used by a control system to aim and concentrate redirected sunlight from heliostats 9 onto focus area 7 .
[0093] Imaging subsystem 11 generally includes a plurality of sensors preferably in the form of imaging devices 28 . In one embodiment, each imaging device 28 is a commercially available digital camera device. In an alternative embodiment, imaging device 28 is to varying degrees a customized device. Imaging devices 28 are mechanically coupled to a support structure 30 and arranged proximal to focus area 7 . Support structure 30 is mechanically coupled to tower 5 proximal to focus area 7 . In another embodiment, support structure 30 is mechanically coupled to the focus area 7 . In another embodiment, support structure 30 is mounted to a separate structure other than tower 5 .
[0094] As illustrated, imaging devices 28 are arranged about the focus 7 in a generally radially symmetric fashion. Other arrangements may be used. For example, an alternate embodiment of imaging subsystem 11 includes a plurality of imaging devices 28 that are arranged about focus 7 in a generally linear symmetric manner. In an alternative embodiment, imaging subsystem support structure 30 is substantially free standing, being independently mechanically coupled to mounting surface 21 . Imaging devices 28 are sufficiently close to focus area 7 so that detected diffraction information can be used in a closed loop control system to actuate reflecting elements 25 for aiming at focus area 7 . However, the devices 28 are far enough away from focus area 7 to avoid undue risk that the devices 28 would be damaged by concentrated sunlight.
[0095] Imaging subsystem 11 includes a plurality of imaging devices 28 having suitable field of view characteristics by which the plurality of diffractive elements 23 are observed. In one exemplary embodiment, each imaging device 28 has an effective field of view such that it can observe the entire plurality of diffractive elements 23 either statically or by the use of opto-mechanical mechanisms or other actuation techniques allowing a plurality of fields of view. In an alternative embodiment individual imaging devices 28 have an effective field of view to observe a subset of the plurality of diffractive elements 23 either statically or by use of optic-mechanical mechanisms allowing a plurality of fields of view. In such an embodiment the union of the plurality of fields of view includes the entire plurality of diffractive elements 23 . In another alternative embodiment a plurality of subsets of imaging devices 28 have effective fields of view such that their intersection and union of observable diffractive elements are equivalent with a given subset and/or the union of all effective fields of view includes the entire plurality of diffractive elements 23 .
[0096] Generally, it desirable that imaging devices 28 provide a color imaging function having sufficient spectral resolution to measure variations in the orientation of diffractive element 23 within fractions of one degree of actuation of reflecting elements 25 . The required spectral resolution is a function of the diffractive properties of diffractive element 23 . In some embodiments of diffractive element 23 , the required spectral resolution is such that a 10-bit color imaging device provides sufficient resolution to measure the orientation of diffractive element 23 . Such embodiments advantageously reduce the cost of imaging device 28 . In other embodiments of diffractive element 23 , the required spectral resolution is such that a 24-bit color imaging device provides sufficient resolution to measure the orientation of diffractive element 23 .
[0097] In addition to providing sufficient spectral resolution, imaging devices 28 must also provide sufficient spatial resolution of diffractive elements 23 included inside respective field of view or views. Spatial resolution of imaging device 28 is affected by the size of pixels provided by focal plane array 131 , and optical properties of lenses 127 . Whether a given diffractive element 23 can be sufficiently resolved depends on these factors, as well as, the physical dimensions of diffractive element 23 , the position of the diffractive element 23 within the field of view, and the distance between diffractive element 23 and imaging device 28 . For a given diffractive element 23 within the effective field of view of imaging device 28 , the minimum spatial resolution preferably is such that diffractive element 23 can resolve at least a single pixel in the image space of imaging device 28 . Because the orientation of diffractive element 23 relative to imaging device 28 is not fixed but can vary within the range of its associated articulation mechanism, the size of diffractive element 23 in the image space of imaging device 28 is not fixed but is rather a function of diffractive element 23 orientation. Consequently, the spatial resolution of imaging device 28 must be sufficient to resolve diffractive element 23 to a minimum of a single pixel in image space over the full range of orientation of diffractive element 23 .
[0098] In one embodiment the spatial resolution of imaging device 28 is such that for each diffractive element 23 included in the effective field of view the minimum respective size in image space is a single pixel over the range of articulation orientations. Such embodiment advantageously minimizes the required resolution of imaging device 28 and consequently the cost of the device as cost is generally directly proportional to spatial resolution.
[0099] In an alternative embodiment, the spatial resolution of imaging device 28 is such that for each diffractive element 23 included in the effective field of view the minimum respective size in image space is an n×m array of pixels over the range of articulation orientations where n and m are integers where at least one of the integers is greater than 1. Such embodiment does not necessarily minimize the spatial resolution of imaging device 28 , however, it advantageously provides a resolution margin. Additionally such embodiments enable imaging device 28 to be deployed in tracking control systems 1 having varying topologies and number of diffractive elements 23 with its effective field of view.
[0100] FIGS. 4A through 4D schematically show front views of exemplary reflective elements fitted with exemplary diffractive elements of the present invention. FIG. 4 a shows an embodiment of diffractive element 23 on reflective element 25 according to the heliostat 9 of FIG. 2 c such that diffractive element 23 is substantially centered in the horizontal direction and substantially along the top edge of reflective element 25 . Such location of diffractive element 23 is advantageous in concentrating solar power systems as it minimizes the risk that diffractive element 23 would be obstructed by neighboring heliostats throughout a full range of functional articulation.
[0101] FIG. 4 b shows diffractive element 24 substantially close to the center of reflecting element 26 . This embodiment may allow obstruction-free observation of diffractive element 24 but may impose a minimum spacing requirement on a CSP system. This embodiment may provide an advantage in minimizing the displacement of diffractive element 24 as a function of rotation of elements 26 and 24 about tip and tilt axes provided that element 24 is located proximal one or more axes of rotation.
[0102] In yet another alternative embodiment of FIG. 4 c , a plurality of diffractive elements 32 are provided on reflective element 38 . The location of diffractive elements 32 are such that at least one diffractive element 32 is not obstructed over the functional articulation range. Such exemplary embodiments include locating two diffractive elements 32 substantially proximal to adjacent corners of reflecting element 38 . FIG. 4 d shows a similar embodiment in which diffractive elements 37 are positioned at opposite corners of reflecting element 36 . Still yet other alternative embodiments may locate any number of diffractive elements on a corresponding reflecting element.
[0103] To understand the use of diffractive elements in the practice of the present invention, we will review the operation of linear diffraction gratings. FIG. 5 shows a linear diffraction grating 51 having regularly spaced grating lines 53 . Diffraction gratings have long been used in devices such as spectrometers to split polychromatic light into its constituent colors in order to characterize the light source or the material that is reflecting/absorbing the light. There are various types of linear diffraction gratings, but in principle they generally incorporate a set of parallel grooves or lines suitably sized and spaced for diffraction, e.g., on the order of the wavelength or even 10× or more of the light band to be diffracted. The spacing of the grooves sets up constructive and destructive interference that result in light of different wavelengths constructively interfering at different angles relative to the incident light beam. Consequently white light passing through a transmission grating or reflecting off of a reflective grating will generate a spectrum of colors similar to the effect of a rainbow. The diffraction angle is a function of both the line spacing, the wavelength of the diffracted light, and the angle of incidence on the grating. The equation below gives the relationship between the diffraction angle θ m , the groove spacing d, the incidence angle θ i and the wavelength λ. The equation has multiple solutions since the interference maxima are periodic. The integer m is the diffraction order and can be positive, negative, or 0.
[0000] d (sin(θ m )+sin(θ i ))= mλ (1)
[0000] The m=0 or 0 th order diffraction is a special case and is equal to the angle of reflection in the case of a reflective grating or the angle of refraction in the case of a transmission grating.
[0104] FIG. 6A shows reflective linear diffraction grating 51 of FIG. 5 viewed on edge and being illuminated with a single polychromatic ray of light 55 that impinges on the diffraction grating 51 perpendicular to its plane. The grating reflects the light, ray 57 and also diffracts the light into multiple diffractive orders 59 through 65 . Each diffractive order is represented schematically by three monochromatic light rays. Angle 67 represents the angle between the 0 th order reflected light ray 57 and the 1 st order diffracted ray 59 . From the above equation we see that angle 67 is independent of the angle of incidence. This means that detection of any of rays 59 through 65 provides information concerning the location of reflected ray 57 .
[0105] FIG. 6B shows incident ray 55 impinging on grating 51 of FIG. 5 at non normal incidence. The reflected 0 th order ray 57 reflects from grating 51 at an angle that is equal to the angle of incidence of ray 55 . The 1 st order diffracted rays 59 maintains the same angular separation 67 relative to the 0 th order reflected ray as does the −1 st order rays 61 regardless of the angle of incidence of ray 55 . The same is true for higher order diffracted rays 63 and 65 .
[0106] Referring to FIGS. 6A and 6B , one skilled in the art will appreciate that a ray of light diffracted from a linear grating 51 is dispersed in one dimension only, into a narrow plane. In the case of a light source like the sun that is less than ½ degree in size, the dispersed light will be confined to a narrow ½-degree region of space.
[0107] Further consideration of this result illustrates that a linear diffraction grating although useful is less than optimum to serve as a more preferred diffraction element 23 of the present invention, since the diffracted light is not observable by an imaging detector 28 unless it happens to lie in that narrow ½-degree region of space, and can be readily detected by more than one of the detectors 28 in only the most fortuitous of circumstances. Further, as the sun moves through the sky during the day and light redirecting element 25 changes angles, this ½-degree region of space moves widely across the sky.
[0108] To solve this problem, more preferred embodiments of the present invention introduce using a diffraction element that has structure in two dimensions, that broadcasts light broadly into three dimensions, so that a large two-dimensional area proximal to target 7 , including at least the area including imaging detectors 28 , is illuminated by the broadcast light.
[0109] The present invention teaches that preferred embodiments of diffractive elements incorporate a circular or spiral grating. For example, FIG. 7 a shows diffractive element 91 having a circular grating formed from concentric rings 93 . FIG. 7 b shows diffractive element 94 having spiral grating 95 . Other less preferred embodiments may use superposed and/or an array of linear gratings that increase the window for observing diffraction effects as compared to a further less preferred embodiment, wherein only a single linear grating is used.
[0110] The aforementioned embodiments describe diffractive elements including sub-elements having uniformly spaced diffraction lines. Alternative embodiments may include sub-elements having non-uniformly spaced diffraction lines. Likewise alternative embodiments may include a plurality of sub-elements having diffraction lines arranged so that respective lines are parallel but having different spacing. Diffractive elements including sub-elements with a plurality of line spacings advantageously allow diffractive elements to provide greater dynamic range by tuning the diffractive orders to overlap.
[0111] Advantageously, circular and spiral gratings effectively provide a continuous set of linear gratings about their center point. This is schematically shown in FIG. 7 c . Consider narrow portion 97 of diffractive element 91 ( FIG. 7 a ). This portion 97 approximates a linear grating with horizontal lines and thereby will generate a diffraction spectrum when illuminated by light orthogonal to the horizontal axis 105 . Likewise, portions 99 , 101 , and 103 , respectively, approximate linear diffraction gratings having a diffractive axes 102 , 104 , and 108 orthogonal to the angle of the cross section, respectively. In the limit that the width of the cross-section goes to zero, there are an infinite number of linear diffraction gratings having diffraction axes completely filling 0° to 360°. The same benefits are provided by circular and spiral gratings. Advantageously, circular or spiral gratings overcome the problems of non-linear effects encountered with linear gratings and are more preferred.
[0112] A single circular or spiral grating, however, does have a disadvantage that the width of the observed spectrum is confined to a narrow line proportional to the angular width of the illuminating source. Consequently such gratings may require a higher resolution imaging subsystem than might be desired in order to observe diffraction spectra of all diffractive elements in the tracking control system 1 . Accordingly, to overcome resolution limitations of single circular or spiral gratings, alternative embodiments of more preferred diffractive elements preferably include a plurality of circular or spiral gratings arranged in a two dimensional array. For example, referring to FIG. 8 a , diffractive element 112 includes a plurality of circular or spiral grating sub-elements 115 . Each sub-element 115 is capable of diffracting incident light in all diffractive axes that when viewed from a relatively close view point can be resolved as a set of parallel spectra 117 as shown in FIG. 8B , e.g., one spectrum for each sub-element 115 in FIG. 8 a . When viewed from relatively far away, the set of parallel spectra 117 of FIG. 8B are resolved as a single spectrum.
[0113] Other embodiments of diffractive elements use sheets incorporating diffraction gratings, similar to the techniques used to make holographic stickers, to produce diffraction information in ways that are more cost effective than using other kinds of linear, spiral, and/or circular gratings. The sheets may be single layers or a laminate of two or more layers. In particular, holographic manufacturing techniques may generate specific dot matrix patterns for a high level of control of the diffractive properties that approximate the effect of linear and circular gratings described herein. Advantageously, holographic manufacturing techniques advantageously provide a low cost method to manufacture high volumes of diffractive elements, as evidenced by the readily available low cost holographic stickers commonly used for security and authentication purposes on consumer goods and packaging.
[0114] To illustrate this, FIGS. 9A through 9C schematically show another embodiment of a diffractive element 106 that includes a plurality of layers including a diffractive layer 107 . Diffractive layer 107 is in the form of an embossed or otherwise fabricated sheet (including a laminated sheet) incorporating one or more diffraction gratings. Desirably, the sheet in some modes practice has been manufactured using techniques similar to those used to fabricate holographic stickers. Element 106 further includes an adhesive layer 109 . Diffractive layer 107 provides any of the aforementioned diffractive properties whereas adhesive layer 109 provides a mechanism by which to mechanically couple diffractive element 106 to a reflective element or associated structure. Diffractive element 106 may include a removable backing layer 111 that prevents diffractive element 106 from prematurely adhering to other entities. This advantageously allows diffractive element 106 to be manufactured in volume, stored, and handled efficiently prior to the removal of backing layer 111 and coupling to a reflective element during assembly. Optionally, diffractive element 106 may include a UV resistant layer 113 applied over diffractive layer 107 that increases the lifetime of diffractive element 23 when exposed to UV doses as in the case of outdoor sun exposure. As another option, the diffractive layer 107 itself may include UV resistant components such as dyes that improve the lifetime under outdoor sun exposure. Furthermore, diffractive element 106 may include additional layers that provide additional diffractive layers, and or mechanical advantages such as stiffness to improve repeatability during the manufacturing or assembly processes.
[0115] FIGS. 10 a and 10 b show an exemplary imaging device 120 suitable in the practice of the present invention. Imaging device 120 includes a mechanical housing 121 , lens housing 123 , and electronic interconnect 125 . Mechanical housing 121 provides general structural support and environmental protection of imaging electronics 129 . Likewise lens housing 123 positions and protects one or more lenses 127 . Imaging electronics 129 includes a focal plane array 131 onto which lenses 127 image objects within the field of view imaging device 120 .
[0116] FIG. 11 shows how imaging subsystem 11 shown in FIGS. 2A and 2B may be incorporated into a tracking control system 150 of the present invention. The tracking control system 150 includes imaging subsystem 11 , computation subsystem 151 , and a plurality of articulation subsystems 153 . Imaging subsystem is electronically coupled to computation subsystem 151 via interconnect 155 by which computation subsystem 151 acquires image data. Computation subsystem 151 is likewise electronically coupled to a plurality of articulation subsystems 153 via interconnects 157 by which computation subsystem 151 delivers pointing instructions to and receives status telemetry from articulation subsystems 153 . Electronic interconnects 155 and 157 may be realized by wired and/or wireless communication topologies. The articulation subsystems 153 actuate corresponding heliostats (not shown) to aim redirected light at a desired target.
[0117] FIGS. 12 a and 12 b show illustrative embodiments of imaging subsystem 11 . Referring to FIG. 12 a , imaging subsystem 11 includes a plurality of imaging devices 152 connected independently or through a common electronic bus 155 to computation subsystem 151 (shown in FIG. 11 ). In an alternative embodiment of FIG. 12 b , imaging subsystem 11 further includes image processing controller 159 coupled electronically to a plurality of imaging devices 152 via a plurality of interconnects 161 . Interconnects 161 include wired and/or wireless communication topologies. Image processing controller 159 provides localized coordination of one or more of the following functions that include image acquisition, image pre-processing, and image transmission to computation subsystem 151 ( FIG. 11 ) via interconnect 155 .
[0118] FIGS. 13 a and 13 b show illustrative embodiments of articulation subsystem 153 . Referring to FIG. 13 a , articulation subsystem 153 includes an articulation processor 163 electrically coupled to articulation mechanism 167 via interconnect 165 . Mechanism 167 is mechanically coupled to a diffractive element (not shown). Articulation processor 163 receives pointing instructions from computation subsystem 151 ( FIG. 11 ) via interconnect 157 to effect articulation of articulation mechanism 167 and the corresponding diffractive element. In an alternative embodiment shown in FIG. 13 b , articulation processor 163 is electrically coupled to a plurality of articulation mechanisms 167 via a plurality of interconnects 165 . Interconnects 165 may be distinct interconnects or be combined in one or more bus topologies.
[0119] FIG. 14 a shows an embodiment of computation system 151 ( FIG. 11 ) in more detail. Computation subsystem 151 includes a plurality of parallel processors 169 . Parallel processors 169 are electrically coupled to imaging subsystem 11 via interconnect 155 and to a plurality of articulation subsystems 155 via interconnect 157 . In some embodiments parallel processors 169 are coupled so that the interconnect 155 and interconnect 157 are distinct logical and/or physical buses. In alternative embodiments such as shown in FIG. 14 b , interconnect 155 and 157 are combined into a single logical and/or physical bus.
[0120] FIG. 15 shows an alternative embodiment of computation system 151 ( FIG. 11 ) in more detail. Computation subsystem 151 includes a master processor 171 and a plurality of slave processors 173 and 179 electrically coupled via interconnect 177 . Master processor 171 provides supervisory control over the plurality of slave processors 173 and 179 , including but not limited to timing and external diagnostic interfacing. Slave processors 179 provide image acquisition and processing via interconnect 155 , whereas slave processors 173 provide articulation control via interconnects 157 .
[0121] The optical properties of diffractive elements according to the present invention advantageously provide a method whereby imaging subsystem 11 ( FIG. 11 ) in conjunction with a computation subsystem 151 ( FIG. 11 ) is able to use observed diffraction information to sense and determine the angular displacement of the 0 th order reflected beam relative to the observation point. FIGS. 16 a through 16 c illustrate this schematically with respect to CSP system 1 of FIGS. 2 a - 2 c and 3 . Referring to FIG. 16 a , diffractive element 23 is illuminated by a distant polychromatic source such that the incident rays 201 that hit diffractive element 23 are substantially parallel. Imaging device 28 receives light scattered, reflected, or diffracted by diffractive element 23 through its lens aperture 127 . The collected ray bundles represented by the edge rays 203 are focused by the imaging device onto a focal plane array 131 . The focused ray bundle is represented by edge rays 205 . As shown in FIG. 16 c , the resulting image 219 contains the sub image 225 of the diffractive element 23 . In the case where imaging device 28 is substantially far away from diffractive element 23 relative to the size of the diffractive element 23 , the angular extent of collected rays 203 is relatively small. Under these conditions we approximate the optics using just the central rays. Exemplary image 219 acquired by imaging device 28 has sub-image 225 that is the mapping of the diffractive element 23 into image space. The location of diffractive element 23 in image space represented by sub-image 225 is given by horizontal coordinate 221 and vertical coordinate 223 .
[0122] FIG. 16 b shows how diffraction information can be used to help determine the location vector of redirected light. In FIG. 16 b , source ray 207 impinges on diffractive element 23 . The reflected ray 211 makes angle 213 relative to the diffractive element normal 212 . The central, collected ray 209 observed by imaging device 28 makes an angle 215 relative to the reflected ray 211 . Angle 217 represents the nominal angular position of diffractive element 23 in imaging device's 27 field of view. Due to the optical effects of diffractive element 23 ; the color of sub-image 225 ( FIG. 16 b ) is a function of angle 215 . In the case that angle 215 lies within one of the non-zero diffractive orders of diffractive element 23 , sub-image 225 will be substantially monochromatic. In the case that angle 215 is 0° (coincident with the reflected beam) sub-image 225 will be the image of the source and will be substantially the color of the source. In the case that angle 215 is between the 0 th and ±1 st diffractive orders of visible light sub-image 225 will be a diffuse image of diffractive element 23 as generally there will be some level of Lambertian scattering.
[0123] Of particular interest is the case in which angle 215 lies within the visible portion of a non-zero diffractive order. Under this condition the color of sub-image 225 provides information about the possible magnitude of angle 215 . FIG. 17 schematically shows this in more detail. Referring to FIG. 17 , imaging device 28 observes diffractive element 23 illuminated by a substantially collimated white light source (not shown) from a distance substantially far away such that sub image 225 ( FIG. 16 c ) is substantially monochromatic and may be characterized by a central wavelength λ. Given the specific diffractive properties of the diffractive element 23 and the observed wavelength λ, the angle between the line of sight 231 between element 23 and imaging device 28 (the camera-element line of sight) and the 0 th order reflected ray, θ m , is constrained to be a member of the set of angles corresponding to this wavelength; one angle for each possible diffractive order. Two such possible angles θ −1 233 and θ −2 235 are shown and correspond to the −1 st and −2 nd order rays for exemplary reflected rays 237 and 239 respectively. Note that these angles and orders are exemplary and do not represent the full set of possible angles for a given observed wavelength λ.
[0124] Furthermore for each possible angle solution for the observed wavelength λ, there are in fact an infinite number of possible reflected ray vectors that lie along the surface of a cone with vertex angle 2θ m . The set of cones share a common axis coincident with the line of sight vector 231 . The cones are represented by their circular bases 241 and 243 for the angles 233 and 235 , respectively. Given the set of possible reflection vectors for the observed wavelength, using the laws of reflection the set of possible incident light vectors also can be determined. The set of all possible incident light vectors lie along the set of cones having a common axis 236 , which is the reflection (off diffractive element 23 ) of the line of sight 231 of imaging device 28 , and having vertex angles 245 and 247 . These cones are represented by their circular bases 249 and 251 in the exemplary solution. By the laws of reflection, angle 245 equals angle 233 , and angle 247 equals angle 235 . Thus, the observed diffraction information allows candidate vector locations of reflected light to be propagated backwards to determine candidate incident light vectors. The set of candidate solutions generally form cones with an apex at the diffractive element 23 , main axes 236 which is the reflection of imaging device line of sight 231 , and cone apex angles that can be determined from the observed diffraction information.
[0125] Whereas the image of a diffractive element 23 from a single viewpoint such as provided by a single imaging device can provide some information about the orientation of the reflected ray, multiple viewpoints provide more specific information. This allows the reflected and incident light vectors to be precisely identified from the diffraction information. The loci of candidate solutions can be narrowed to a single solution very accurately.
[0126] For example, a two viewpoint embodiment provides sufficient information by which to constrain reflected ray orientation to at most two possible vectors and in some limited cases, can uniquely constrain the reflected ray orientation. FIG. 18 shows this schematically. Referring to FIG. 18 , a diffractive element is represented as point 261 having a normal vector 265 lying in plane 285 and passing through the intersection of planes 285 and 287 . Imaging devices having viewpoints represented by points 269 and 271 lie on plane 285 at the intersection with plane 287 . Light ray 273 is incident on point 261 representing the diffractive element and is in plane 285 . Reflected and diffracted ray 275 also is in plane 285 and passes through plane 287 at point 267 . At the outset, the location of ray 275 is unknown, but the location can be determined from diffraction information according to principles of the present invention. Lines of sight 277 and 279 form angles 291 and 292 with the reflected ray 279 respectively resulting in observed diffraction information, e.g., an observed color, per viewpoint of diffractive element 261 . Circles 281 and 283 represent the locus of possible reflected rays that would result in the color observed at viewpoints 267 and 271 respectively. The intersection of 281 and 283 is a single point 267 which is in fact the unique solution to the two viewpoint observation. Thus, the vector corresponding to ray 275 is precisely determined using two viewpoints in this illustration.
[0127] FIG. 19 shows another instance in which two viewpoints provide a single solution. Referring to FIG. 19 a similar two viewpoint constraint is demonstrated in which incident ray 273 reflects and diffracts from diffractive element 261 such that reflected and diffracted ray 275 is in plane 285 and intersects plane 287 at point 267 . In this example the location of intersection 267 is such that it is not located between viewpoints 269 and 271 , although at the outset the location of point 267 is unknown but can be determined using principles of the present invention. In this instance the locus of constant color rays represented by circle 283 for viewpoint 271 is encircled by locus of constant color rays 281 for viewpoint 269 . The two loci have a single intersection point 267 . This is the unique solution for reflected ray 275 provided by the observed diffraction information from locations 269 and 271 . In fact, it can be shown that for any reflected ray 275 lying along plane 285 , the loci of constant color points from viewpoints 269 and 271 have a single intersection 267 . This allows the location of reflected ray 275 to be precisely determined.
[0128] In many cases, however, the plane of incidence and reflection is not coplanar with plane 285 (which is the line of sight plane between diffractive element and the observation point), and a unique locus intersection does not exist using only two viewpoints. Using principles of the present invention, however, observing diffraction information from more than two viewpoints provides a unique solution in this circumstance. Three viewpoints is sufficient. Four viewpoints allows a unique solution with very high precision and extra information for redundancy. More than four can be used, but may not be needed. This is shown in FIG. 20 .
[0129] Referring to FIG. 20 , incident ray 273 and reflected ray 275 lie in plane 291 that is not coplanar with plane 285 . Resulting constant color loci 281 and 283 for viewpoints 269 and 271 respectively intersect at point 267 which lies along reflected ray 275 . In addition, loci 281 and 283 have a secondary intersection at point 293 . This intersection represents an alternative reflected ray that would result in the same set of observed colors from the two viewpoints 269 and 271 . At the outset, it would not be known which solution is correct in many situations. Consequently, observation of diffractive element 261 from two viewpoints alone does not provide unique determination of the reflected ray vector 275 . In some possible embodiments, existence of certain constraints may provide sufficient knowledge to overcome the aforementioned ambiguity associated with the two viewpoint observation. One such constraint includes constraints on the location of the light source. In particular, in the case of a concentrating solar power system, it is possible that one of the two possible solutions 267 and 293 is not feasible because it would imply a sun position that is below the horizon. In alternate applications various other constraint(s) may be used to resolve which of the two possible solutions is correct.
[0130] Another approach to resolve the possible ambiguity with the two viewpoint observation is a step and observe method. This method uses multiple observations as a function of orientation of diffractive element 261 to determine which of the two solutions 267 or 293 describes the real reflected ray 275 . In effect, this adds additional viewpoints, allowing the solution to be solved.
[0131] Yet another approach to overcome ambiguity present in the two viewpoint observation is the addition of at least a third viewpoint. This is shown in FIG. 21 . Referring to FIG. 21 , third viewpoint 295 having line of sight 297 to point 261 is added. Viewpoint 295 lies in plane 287 to observe diffraction information such as color that is a function of the angle formed between line of sight 297 and reflected ray 275 . The locus of constant color for viewpoint 295 is represented by circle 299 . Points 293 represent the set of intersections between exactly two loci circles 283 / 281 and 283 / 299 . In contrast, point 267 represents the unique intersection of all three loci circles 281 , 283 , and 299 . Consequently, color observation from three distinct viewpoints 269 , 271 , and 295 provides unique determination of the vector corresponding to reflected ray 275 .
[0132] Thus, three distinct viewpoints are sufficient to uniquely determine the orientation of reflected ray vectors originating from a known point (e.g., point 261 in FIGS. 18-20 ) in space. In general four or more distinct viewpoints may be used. In such embodiments, viewpoints in excess of three may provide redundancy function, which may be helpful, for instance, in case a particular viewpoint is obstructed.
[0133] The diffraction information used for illustrative purposes in FIGS. 18-20 is color. A variety of different kinds of diffraction information can be used singly or in combination in control systems of the present invention. For example, in addition or as an alternative to observed color of diffractive element 261 from a plurality of viewpoints, the relative intensity of the observed light also provides information that may be used to determine the orientation of a reflected ray. In particular, relative intensity is useful for determining whether two or more viewpoint observation correspond to the same or different diffraction orders.
[0134] FIGS. 20-21 and the corresponding discussion show how three or more distinct viewpoints provide a unique characterization of the orientation of a ray 275 reflected from a viewpoint 261 . The relationship can be represented by equation 2:
[0000] C i =A i ·R i (2)
[0000] Where C, is a vector having an element corresponding to the color observed from the i th diffractive element 23 , R i is a unit vector corresponding to the orientation of reflected and diffracted ray 275 for the i th diffractive element 261 relative to a known reference coordinates space, and A i is a transformation matrix that maps reflected ray unit vector into the color vector for the i th diffractive element 261 . Given color observation from three or more viewpoints and transformation A i , it is possible to determine the orientation of the reflected ray by using the inverse of equation 2:
[0000] R i =A i −1 ·C i (3)
[0135] Furthermore, referring to FIG. 22 , in a typical mode of practice such as with respect to CSP system 1 of FIGS. 2A-2C and 3 , it is desirable that light redirecting elements 25 be oriented in such a manner such that reflected rays 305 from each light redirecting element 25 resulting from incident rays 303 substantially intersect a known point in space referred to herein as the nominal target 301 of the light redirecting elements 25 when these are aimed as desired to concentrate sunlight. In FIGS. 2A-2C , this corresponds to the focus area 7 . Consequently, for each light redirecting element 25 , there is a vector that describes the desired orientation of the reflected ray 305 from a light redirecting element 25 to the nominal track point 301 . FIG. 22 shows a single nominal track point 301 for the entire plurality of light redirecting elements 25 , and this nominal track point 301 preferably is substantially fixed in position relative to the control system
[0136] Referring to FIG. 23 , in an alternative embodiment, there may be a plurality of nominal track points 301 . In such alternative embodiments each nominal track point 301 may be associated with a subset of the plurality of light redirecting elements 25 .
[0137] Referring to FIG. 24 , in another alternative embodiment, the nominal track point 301 is substantially fixed for a period of time and then moved to another location 309 for another period of time. After the track point is shifted to location 309 , new aiming vectors 307 result. The number of fixed locations and the duration of respective periods are not constrained. In yet another alternative embodiment the location of the nominal track point is a substantially continuous function of time.
[0138] In illustrative modes of practice, at a given instant in time there is a substantially fixed nominal track point associated with a single light redirecting element from which a desired reflected ray vector r i,0 can be determined such that reflected rays generally intersect the desired nominal track point. Consequently, according to equation 2 there is a color observation vector c i,0 that represents this desired reflected ray vector. Given a color observation c i,j that corresponds to the multi-viewpoint observation of the i th diffractive element at a known orientation represented by a unit normal vector n i,j . The value of the unit normal is a function of the orientation of the articulation mechanism associated with the diffractive element. Mathematically, the unit normal of a diffractive element can be described by the following vector equation:
[0000] N i =B·X i (4)
[0000] Where N i is the unit normal of the i th diffractive element, X i is a vector describing the quantities of each degree of freedom of articulation mechanism, and B is the transformation matrix that maps articulation coordinates into the diffractive element unit normal.
[0139] An exemplary method of performing closed loop tracking of a plurality of articulating diffractive elements in order that the reflected rays substantially intersect a known location includes the following steps, desirably implemented for every diffractive element and light redirecting element within the scope of the control system. Procedure 1 is as follows:
1. Sample the color vector C i including as vector elements the observed color from a plurality of distinct viewpoints. 2. Compute the difference between the observed color vector C i and the nominal on target color vector C i0 herein referred to as ΔC i . 3. Compute articulation compensation vector ΔX i such that
[0000]
lim
Δ
C
i
->
D
Δ
X
i
=
0
4. Apply ΔX i to articulation mechanism.
5. Repeat steps 1-4
[0145] An alternative method of performing closed loop tracking of a plurality of articulating diffractive elements in order that the reflected rays substantially intersect a known location includes the following steps for every diffractive element according to Procedure 2:
1. Compute open loop articulation coordinate X i based on geospatial coordinates, local date and time, and position relative to the target position. 2. Apply open loop articulation coordinate Xi to articulation mechanism 3. Sample the color vector C i including as vector elements the observed color from a plurality of distinct viewpoints. 4. Compute the difference between the observed color vector C i and the nominal on target color vector C i0 herein referred to as ΔC i . 5. Compute articulation compensation vector ΔX i such that
[0000]
lim
Δ
C
i
->
D
Δ
X
i
=
0
6. Apply ΔX i to articulation mechanism.
7. Repeat steps 1-6
[0153] Yet another alternative method includes the following steps according to Procedure 3:
1. Generating a lookup table of articulation coordinates X i [t] where t is the local time of day such that X i [t] is the last known substantially on target articulation coordinate at time t. 2. Interpolate X i coordinate for the current time based on lookup table. 3. Apply interpolated X i coordinate for the current time based on lookup table. 4. Sample the color vector C i including as vector elements the observed color from a plurality of distinct viewpoints. 5. Compute the difference between the observed color vector C i and the nominal on target color vector C i0 herein referred to as ΔC i . 6. Compute articulation compensation vector ΔX i such that
[0000]
lim
Δ
C
i
->
D
Δ
X
i
=
0
7. Apply ΔX i to articulation mechanism.
8. Repeat steps 2-6
[0162] In illustrative modes of practice, any of Procedures 1 to 3 is used in a CSP system in which a plurality of heliostats concentrate sunlight onto one or more targets. The heliostats include light redirecting elements that allow sunlight to be redirected. The light redirecting elements are mechanically coupled to articulation mechanisms allowing controlled articulation of the light redirecting elements. Corresponding diffractive elements are coupled to the light redirecting elements so that diffraction information produced by the diffractive elements is indicative of how the light redirecting elements are aimed. The system includes an imaging subsystem comprising one or more imaging devices in a position effective to observe diffraction information produced by the diffractive elements that is indicative of the aim of the corresponding light redirecting elements. Preferably, the imaging devices are mechanically coupled to a support structure and are arranged proximal to the one or more targets. A computational subsystem including one or more computational devices is operationally coupled to the imaging devices so that the diffraction information captured by the imaging devices can be used to controllably aim the light redirecting elements at the desired target(s).
[0163] The complete disclosures of the patents, patent documents, technical articles, and other publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that this invention is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the invention intended to be limited only by the claims set forth herein as follows. | The present invention relates to apparatus and methods to provide a control system for the purpose of redirecting light from a source onto a target. The present invention appreciates that the diffraction pattern for light that is both diffracted and re-directed by a heliostat is a function of how the light redirecting element is aimed. This means that the aim of the light redirecting element can be precisely determined once the aim of the diffracted light is known. Advantageously, the characteristics of diffracted light indicative of how the diffracted light is aimed can be determined from locations outside the zone of concentrated illumination in which sensors are at undue risk. This, in turn, means that diffracted light characteristics can be detected at a safe location, and this information can then be used to help precisely aim the light redirecting element onto the desired target, such as a receiver in a CSP system. The aim of the diffracted light is thus an accurate proxy for the light beam to be aimed at the receiver. | 5 |
[0001] The present invention relates to a process for finishing a cellulose-based textile as well as a cellulose-based textile finished according to this process.
[0002] Cross-linking textile finishes are currently used for conferring on cellulose fabrics properties of durable press and resistance to creasing or crease recovery, a dimensional stability to domestic washes as well as easy care (easy ironing or no ironing), among other properties.
[0003] Most of these cross-linking textile finishes contain free or combined formaldehyde which is released either in the finishing shop or when using fabrics finished in this way. However, formaldehyde is now considered to be a noxious product, exposure doses of which are limited to very low values by certain national regulations.
[0004] In U.S. Pat. No. 3,304,312 4,5-dihydroxy or 4,5-dialkoxy derivatives of 2-imidazolidinones, are disclosed as non-formaldehyde textile finishing agents for imparting crease resistance. The impregnated material is subjected to drying and curing operations at a temperature in the range of 82° C.-232° C.
[0005] These compounds are widely used in Pad-Dry and Cure or Pad-Dry-Cure finishing processes where a cellulose containing fabric is impregnated with a bath containing these non formaldehyde cross-linking agent, a catalyst and additives. The impregnated fabric is dried and cured at elevated temperatures; the drying and curing steps may be consecutive or simultaneous. In the case where the fabric is first dried, curing temperatures from 120° C. to 230° C. are described (U.S. Pat. No. 4,295,846)
[0006] Unfortunately, finished fabrics according to this prior art, have low resistance to tearing, show a great tendency to yellowing, and may generate an unpleasant amine smell.
[0007] Furthermore to increase the easy-care properties of the finished fabrics, one can increase the concentration of these non-formaldehyde crosslinkers but at the expense of the whiteness and the tear strength. The bad amine smell is then also promoted.
[0008] It is known by the artisan, as described in Textile Chemist and Colorist 1982 (Cooke and al. 14(5), 100-106, 1982), that the necessary acidic conditions (pH from 3 to 5) not only catalyse the etherification of the cellulose, but also give an undesired side reaction where dialkylhydantoins are formed thus reducing the efficiency of the crosslinker (degrees of fixation of the resin of from 50 to 70% are generally observed).
[0009] Surprisingly, it has now been discovered that non formaldehyde crosslinkers can be applied under extreme acidic conditions to a cellulose based fabric in a moist cure process (a combination of impregnation, padding, gentle drying, low temperature curing and washing) to give good easy-care properties. The finished fabrics according to this invention have an excellent whiteness level, a very high tear strength, and no unpleasant amine smell.
[0010] This invention provides a formaldehyde free cross-linking finishing process of cellulose fabrics or cellulose containing fabrics.
[0011] The compounds used in this invention have the general formula (I)
[0000]
[0012] Either the cis or trans isomer type or mixtures thereof may be used,
[0000] wherein
X is O or S, preferably O,
R 1 , R 2 are the same or different and are
linear or branched C 1 -C 20 -alkyl, preferably C 1 -C 8 -alkyl, most preferably methyl, or
linear or branched C 2 -C 20 -alkyl, preferably C 2 -C 8 -alkyl, substituted by one or more functional groups like hydroxyl, amino, carboxyl, amide, ester, ether, and halogen (fluorine, chlorine, bromine and iodine),
R 3 , R 4 are the same or different (R 3 and R 4 may be part of the same ring structure)
and are H or
linear or branched C 1 -C 20 -alkyl, preferably C 1 -C 8 -alkyl, eventually substituted by one or more functional groups like hydroxyl, amino, carboxyl, amide, ester, ether, and halogen (fluorine, chlorine, bromine and iodine),
or
groups like
[0000]
where
n is 1-20, preferably 1-6, most preferably 2, and
R 5 is H or linear or branched chain alkyl C 1 -C 4 , preferably H.
[0024] Most preferably R 1 and R 2 are methyl and R 3 and R 4 are H or methyl or —(CH 2 ) 2 OH
[0025] Preferred compounds of the invention are 1,3-Dimethyl-4,5-dihydroxy-2-imidazolidinone (also called DMeDHEU, DiMethylDiHydroxyEthylenUrea) and its etherified derivatives. To partly or completely etherify the DMeDHEU, the preferred alcohols are methanol or DEG (diethylenglycol) or mixtures thereof.
[0026] These products are generally commercial and sold by example under the trade name Arkofix NZF New (Clariant) or can be prepared by different techniques known to the man skilled in the art as described among other possible processes in U.S. Pat. No. 3,304,312, U.S. Pat. No. 4,295,846, EP 0 141 755, or U.S. Pat. No. 5,707,404. The process is generally a condensation of glyoxal and a di-substituted urea followed or not by an etherification step with one or more alcohol or polyol.
[0000] Process of this Invention:
[0027] The process of this invention is characterised by the following steps
a) Impregnation of a cellulose containing fabric with a bath containing a non formaldehyde cross-linking agent of formula (I) and a catalyst or a mixture of catalysts under acidic conditions, b) Drying at a temperature of 130° C. or below to a residual moisture of from 3 to 30%, and c) Curing at a temperature of 50° C. or below.
[0031] Afterwards the fabric is washed, neutralised and dried by operations known in the art.
[0032] Optionally an additional top-finishing step may complete the instant process.
DETAILED DESCRIPTION OF THE INVENTION
[0033] A cellulose containing fabric is impregnated with a bath containing a non formaldehyde cross-linking agent of formula (I) and a catalyst or a mixture of catalysts.
[0034] The concentration of the finishing agent of formula (I) in the bath calculated as solid is generally governed by the desired effect. As a rule it is between 30 and 500 g/l, preferably between 100 and 300 g/l, most preferably between 120 and 240 g/l.
[0035] Catalysts suitable for this process are one single acid or combinations of organic and inorganic acids or acid donors. The cross-linking of the cellulose is acid-catalysed; the bath pH is adjusted to 3 or below, preferably to 2 or below, and most preferably to 0.8-1.5.
[0036] Typical catalysts include acids such as hydrochloric, sulphuric, fluoroboric, phosphoric, nitric, acetic, glycolic, maleic, lactic, citric, tartaric, muriatic and oxalic acids; metal salts such as magnesium chloride, nitrate, fluoroborate, or fluorosilicate; zinc chloride, nitrate, fluoroborate, or fluorosilicate; ammonium chloride; zirconium oxychloride; sodium or potassium bisulfate; amine hydrochlorides such as the hydrochloride of 2-amino-2-methyl-1-propanol; and the like and mixtures thereof. Preferred are hydrochloric acid, sulphuric acid, phosphoric acid or ammonium chloride.
[0037] Optionally, additives may be added to the bath. Conventional additives such as wetting agents, lubricants, softeners, bodying agents, water repellents, flame retardants, soil shedding agents, mildew inhibitors, anti-wet soiling agents, fluorescent brighteners, biocides (anti-microbial, anti-bacterial, anti-algae, anti-fungi, insect repellent, anti-dust mite, anti-mould) and the like may be used in the treating bath in conventional amounts as long as the stability of the bath is compatible with the very low pH range of the invention. Such auxiliaries must not, however, interfere with the proper functioning of the finishing resin, must not themselves have a deleterious effect on the fabric, and desirably are free of formaldehyde. Preferred are wetting agents, lubricants and softeners.
[0038] The impregnated fabric is dried at low temperature below 130° C., preferably below 100° C. and most preferably between 60 and 90° C. to a residual moisture of from 3 to 30%, preferably from 5 to 15% and most preferably of from 6 to 10%.
[0039] The fabric being kept at this humidity either by being wrapped with a plastic film or by any other means, is cured at low temperature, below 50° C., preferentially below 40° C., to avoid fibre damage for 5 to 30 h, preferentially for 15 to 25 h. During that curing stage the fabric is preferentially kept under rotation to avoid migration and local over-concentration of the catalyst that could damage the fabric.
[0040] After the curing, the fabric is washed and neutralised with any conventional method generally used by the man skilled in the art. Neutralisation may be achieved for example with a base like caustic soda or just by rinsing.
[0041] After the washing and neutralisation step, the fabric is dried. Optionally, but preferably, the fabric is top-finished with a bath containing additives. This step can be subsequent to the drying or the fabric can be padded after the washing in a wet-in-wet process and then dried.
[0042] Conventional additives such as wetting agents, lubricants, softeners, bodying agents, water repellents, flame retardants, soil shedding agents, mildew inhibitors, anti-wet soiling agents, fluorescent brighteners, biocides (anti-microbial, anti-bacterial, anti-algae, anti-fungi, insect repellent, anti-dust mite, anti-mould) and the like may be used in the top-finish bath in conventional amounts as long as the bath is stable. Such auxiliaries must not, however, interfere with the proper functioning of the finishing resin, must not themselves have a deleterious effect on the fabric, and desirably are free of formaldehyde.
[0043] The non-formaldehyde finished fabrics according to the disclosed process, have easy-care properties and furthermore have a better tear strength, a high whiteness level (no yellowing) and do not generate any unpleasant amine smell.
[0044] The following examples shall explain the instant invention in more detail.
[0000]
parameter
method
Durable Press
AATCC 124
Tear strength
NF G07-149
Tensile strength
NF G07-001
Degree of Fixation
[0045] The degree of fixation is obtained by the nitrogen determination (N %) of the fabric before and after washing by elementary analysis.
[0000] Degree of fixation=100×N % washed fabric/N % finished fabric
EXAMPLE 1
Moist Cure with a DMeDHEU Based Crosslinker
[0046] A bleached white 100% cotton toile 1/1 (116 g/m 2 , 40×27.5 treads/cm) was impregnated in a bath according to recipe #1. The material was squeezed to a wet pick-up of 65%, and then it was dried with hot air having 70° C. to a residual moisture of 7-8%. The material was wrapped in a plastic bag and was allowed to stand at 35° C. for 24 hours (curing). Thereupon it was promptly washed, neutralised, rinsed with water at 30° C. for 5 minutes then squeezed and dried at 120° C. After the drying, the material was impregnated and squeezed with recipe A to a wet pick up of 60%, and dried at 130° C. (top-finish).
COMPARATIVE EXAMPLE 1
Pad-Dry-Cure with a DMeDHEU Based Crosslinker
[0047] The fabric of example 1 is impregnated in a bath according to recipe #2. The material was squeezed to a wet pick-up of 65% then it was dried and cured at 150° C. (effective time at 150° C.: 60 seconds).
[0048] The details of the recipes are shown in Table 1.
[0000]
TABLE 1
Recipes:
Products
1
A
2
Sandozin MRN liq conc
g/l
0.3
0.3
0.3
(commercial wetting agent*)
Arkofix NZF New liq
g/l
440
440
(commercial DMeDHEU based
crosslinker*)
Catalyst MC1 liq (commercial
g/l
110
mixture of organic and
inorganic acids*)
Catalyst NKD liq (commercial
g/l
18
magnesium chloride catalyst
with organic acid*)
Sandolube SVN ZP liq
g/l
40
20
40
(commercial non ionic
polyethylene softener*)
Sandoperm MEW liq
g/l
30
10
30
(non ionic silicone
microemulsion*)
Sandoperm RPU liq
g/l
30
(commercial polyurethane
softener*)
pH of bath
1.2
4.2
3.9
*available from Clariant
Results:
[0049] 0=un-treated fabric
[0000]
TABLE 2
example
0
1
comp ex 1
Durable Press (5 × 60°
1.8
3.4
3.2
C. washes, tumble dried)
Tear strength - Elmendorf
cN
1059
1483
958
(weft)
Tensile strength (weft)
daN
57.2
36.4
37.5
Degree of fixation
%
—
45
64
[0050] These results clearly demonstrate a surprising increase of the tear strength when the fabric is treated by the instant moist cure process.
EXAMPLE 2
Moist Cure with a DMeDHEU Based Crosslinker
[0051] A bleached white 100% cotton poplin (120 g/m 2 ) was impregnated in a bath according to recipe #3. The material was squeezed to a wet pick-up of 75%, then it was dried with hot air having 90° C. to a residual moisture of 9%. The material was wrapped in a plastic bag and was allowed to stand at 20° C. for 22 hours. Thereupon it was promptly rinsed, neutralised with caustic soda, rinsed with water for 10 minutes, acidified with acetic acid, rinsed again then squeezed and dried at 120° C. After the drying, the material was impregnated and squeezed with recipe B to a wet pick up of 75%, and dried at 120° C.
COMPARATIVE EXAMPLE 2
Pad-Dry-Cure with a DMeDHEU Based Crosslinker
[0052] The fabric of example 2 is impregnated in a bath according to recipe #4. The material was squeezed to a wet pick-up of 75% then it was dried for 45 seconds at 120° C. and cured for 30 seconds at 160° C.
COMPARATIVE EXAMPLE 3
[0053] The finished material of comparative example 2 was washed with 1 g/l of a detergent/wetting and dispersing agent for 15 minutes at 45° C. then was rinsed with water, squeezed and dried for 45″ at 120° C.
[0054] Details of the recipes are shown in Table 3.
[0000]
TABLE 3
Recipes:
Products
3
B
4
Sandozin NRW liq conc
g/l
0.3
0.3
0.3
(commercial wetting agent*)
Arkofix NZF New liq
g/l
440
200
(commercial DMeDHEU based
crosslinker*)
Concentrated sulfuric acid
cc/l
11
Catalyst NKD liq
g/l
18
(commercial magnesium chloride
based catalyst *)
Sandolube SVN liq
g/l
50
50
(commercial non ionic
polyethylene softener*)
Ceraperm MW liq
g/l
30
30
(non ionic silicone
microemulsion*)
pH of bath
1.1
4.2
3.5
*available from Clariant
Results:
[0055] 0=un-treated fabric
[0000]
TABLE 4
Example
comp
comp
0
2
ex 2
ex 3
Durable Press (1 × 60°
1
3
3.2
C. wash, tumble dried)
Tear strength - Elmendorf (warp)
cN
995
1148
802
795
Tear strength - Elmendorf (weft)
cN
683
694
540
545
Degree of whiteness (CIE)
°
75.1
77.8
73.5
74.9
Degree of fixation
%
48
67
[0056] The results clearly show that the instant process leads to better properties of the textile fabric, especially the problem of yellowing has been solved and the tear strength is far better. It can also be seen that the improvement of tear strength and whiteness cannot be achieved from an additional washing step after a pad-dry-cure process, but is only obtainable with the instant process. | The instant invention relates to a process for the finishing of textiles with a non formaldehyde cross-linking agent based on 2-imidazolidinones wherein by certain process parameters in drying and curing the undesired yellowing and unpleasant amine smell is avoided. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention:
This invention relates generally to speakers, and more particularly, to speaker enclosures. Even more specifically, this invention relates to a speaker enclosure which can be disassembled quickly and easily to facilitate handling and storage of the speaker, and particularly large speakers.
2. Prior Art:
There are many different types of speakers known in the prior art, including speakers having hinged or folded speaker boxes (see U.S. Pat. Nos. 2,036,832 and 4,014,597) and speakers having partitions defining folded folded horns (see U.S. Pat. No. 2,826,260). However, none of these prior art speaker designs teach a speaker enclosure which can be quickly and easily disassembled and assembled.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a speaker having an enclosure which is releasably secured together by a clamping means comprising reinforcing fastening strips and quick-connect disconnect fasteners, so that the speaker may be quickly and easily disassembled and assembled. This greatly facilitates handling and storage of speakers, particularly large speakers, and enables the speaker board, containing the speakers, to be safely stored and handled.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings, wherein like reference numerals indicate like parts throughout the several views, the several forms of the invention are illustrated in detail in the figures, wherein:
FIG. 1 is a perspective view of a speaker enclosure constructed in accordance with the invention;
FIG. 2 is a sectional view in side elevation of the speaker enclosure of FIG. 1;
FIG. 3 is an exploded perspective view of the speaker enclosure of FIGS. 1 and 2;
FIG. 4 is a plan view of the bottom wall of the speaker enclosure of FIGS. 1-3;
FIG. 5 is a view in elevation of one of the sides of the speaker enclosure of FIGS. 1-3;
FIG. 6 is an exploded view in elevation of a modification of the speaker enclosure of FIG. 1;
FIG. 7 is a plan view looking down on the speaker enclosure of FIG. 6, with the top wall removed; and
FIG. 8 is a fragmentary perspective view of a second modification of the speaker enclosure of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first form of speaker enclosure is indicated generally at 10 and comprises opposite sides 11 and 12, a top 13, bottom 14, back 15, speaker board 16 and grill 17.
The top 13 and bottom 14 are substantially identically constructed, and each includes a panel 18 of wood or other suitable material, either finished naturally or covered with leather or any desired finish, with a pair of reinforcing fastening strips 19 and 20 along opposite sides of the panel, spaced inwardly from the edge thereof and parallel thereto. A second pair of strips 21 and 22 are fastened on top of the first pair of strips, extending transversely thereto parallel to the other edges of the panel. A pair of stud bolts or other suitable fasteners 23 and 24 are secured to the second pair of strips near the opposite ends thereof, and a stud bolt or other suitable fastener 25 is secured to one of the first pair of strips 20 at the midpoint thereof and projects outwardly toward the adjacent edge of the panel.
The opposite sides 11 and 12 are similarly constructed, and each includes a panel 26 with a first pair of strips 27 and 28 along opposite edges of the panel, spaced from the edge and parallel thereto. A second pair of strips 29 and 30 are secured on top of the first pair of strips, extending transversely thereto, and spaced inwardly from the ends of the first pair of strips. The second pair of strips 29 and 30 each have a pair of holes 31 and 32 therethrough, for receiving the stud bolts 23 and 24 carried by the second pair of strips on the top and bottom panels, respectively. Wing nuts or the like 33 are then threaded onto the stud bolts 23 and 24 for fastening the top, bottom and sides together.
The back 15 has a pair of holes 34 and 35 therethrough near the top and bottom edges, and the adjacent outer surface portions are countersunk at 36 and 37. The stud bolts 25 are extended through the holes 34 and 35 and wing nuts or the like 38 are threaded onto the stud bolts to secure the back to the top and bottom.
The walls of the enclosure are held together by a clamping means comprising the reinforcing fastening strips and the quick-connect disconnect fasteners being the bolts and wing nuts. The quick-connect disconnect fasteners hold the strips to one another holding the enclosure together.
The speaker board 16 is held to the top, bottom and sides by the pressure exerted on the edges thereof when the top, bottom and sides are secured together by the stud bolts and wing nuts. As shown, the speaker board carries one or more speakers, such as woofer W, midrange speaker Sm and bass speaker Sb. An electrical lead 39 to the speakers has a quick-disconnect coupling 40 for releasably connecting the speakers to a complemental lead 41 extending through the back 15.
A gasket 42 of foam rubber, felt or other suitable material is disposed between the back 15 and adjacent strips 20 on the top and bottom and strips 28 on the opposite sides of the enclosure, to ensure that the back is tightly secured against the top, bottom and sides.
The reinforcing fastening strips are spaced inwardly from the edges of the associated panels a distance such that when the top, bottom, sides and back are assembled together, the edges are flush, as seen in FIGS. 1 and 2.
A second form of the invention is shown in FIGS. 6 and 7, and is substantially identical to that shown in FIGS. 1-5, except that the back is held on by quarter turn spring latches 43 along opposite edges of the back 15'. The spring latches 43 may be of conventional construction, and include latching projections 44 at the inner ends thereof, and hand operated knurled knobs 45 at the outer ends thereof. Also, quarter round strips 46 and 47 may be provided at the opposite side edges of the speaker grill or board. In other words, the speaker board is held against the strips on the top, bottom and side panels by the quarter round strips, in addition to the clamping pressure provided by the tightened down sides, top and bottom.
A third form of the invention is shown in FIG. 8, and is substantially identical to the forms previously described, except that the speaker board 16' may be slipped into a channel 48 formed between the strips 27 and an angle member 49 fastened to the sides in spaced, parallel relationship to the strips 27.
The panels, strips and speaker board may be made of wood or other suitable materials, and other quick-connect disconnect fasteners than the stud bolts and wing nuts may be used. | A readily portable speaker enclosure having sides, a back and a top and bottom releasably held together by a clamping assembling wherein reinforcing fastening strips secured to the walls are held together by quick-connect disconnect fasteners, and a speaker board carrying speakers releasably held by the sides, top and bottom, whereby the speaker enclosure may be easily disassembled for storage or transport, thereby facilitating handling of large speakers. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to downloading data from or uploading data to information sources via information networks and, in preferred embodiments, relates to techniques for retrieving files such as web pages and other web content in an Internet environment.
Currently, the Internet operates under the hypertext transfer protocol (HTTP) and embodies a client-server architecture. The vast majority of Internet access—about 99%—is achieved via web browser programs, predominantly Netscape or Microsoft Internet Explorer, whose trade marks are acknowledged.
Existing download techniques will be discussed later with reference to FIGS. 1( a ) and 1 ( b ) but, typically, the client is a user's terminal such as a PC, a suitably-adapted (e.g. Wireless Access Protocol or WAP) mobile telephone or other communications device running a browser program. This terminal downloads and displays a desired HTML web page held on a web server by using a communications network to send a request for that web page across the Internet to the appropriate server. The server responds by sending the requested web page back across the Internet and from there to the client via the communications network to which the user's terminal is connected.
Whilst a web page is mentioned by way of example, other web content files such as .gif, .jpg or .mpg files can be downloaded in the same way.
The client and server can be in direct contact across the Internet via the communications network or can be connected via a proxy server acting between the client and the server. The purpose of the proxy server is to cache some web pages, usually as a result of previous user requests, so that future user requests for the cached web pages can be satisfied without connecting to the server. If the user requests a web page that is not cached on the proxy server, the proxy server forwards the request to the server and receives and forwards the requested page from the server to the client. However, in general, less traffic needs to connect to the server and so the average download time is decreased.
Cache techniques are, of course, commonplace in the Internet art. Most commonly, when a server or a proxy server responds to a user's request by sending a web page back to the client, that page may be cached on the user's terminal so that future user requests for the same web page can be satisfied immediately without having to connect to the server or the proxy server at all. Nevertheless, the user's terminal cannot cache every page that the user ever downloads, and the user will naturally wish to update cached web pages and to download new web pages from time to time. This means that efficient downloading remains paramount.
Despite ongoing efforts to speed Internet usage with faster modems and high-speed network technologies such as ADSL and optical cable, the majority of Internet users are burdened with slow download times. Even if an Internet user invests heavily in a fast modem and in subscribing to a high-speed communications network, the user may still suffer delays due to the architecture of the Internet itself and the nature of its components. Particular problems arise due to the limited speed with which servers can operate and the restricted bandwidth of the numerous communications channels that lie between the server and the client. There is also the problem of unreliability, meaning that if a server is down and no cached copy of the desired web page is accessible elsewhere, the user may have to wait until the server is operational again.
The slowness and unreliability of downloads makes the Internet less useful and appealing than it could and should be, to the detriment of users and also those who seek to provide information to users. Recent research suggests that, on average, a user will wait just eight seconds for a web page to download before moving on elsewhere. If that happens, the user misses information that could have been beneficial and the provider of the web page misses an opportunity to convey that information, possibly resulting in lost business and decreased advertising revenues. The problem is likely to get worse until efforts to upgrade the Internet and its associated communications technologies begin to outweigh the explosion of new Internet users and the move towards ‘always-on’ Internet access.
SUMMARY OF THE INVENTION
Broadly, this invention contemplates a method of downloading data via a client-server communications network, which network comprises a plurality of clients each having a local cache storing data downloaded via the network. The method comprises responding to a data request made to the network by a first client by uploading data from the cache of a second client and transmitting that data across the network to the first client.
In use of a first architecture, the invention may be defined as a method of downloading or uploading data via a client-server communications network that includes a server and a plurality of clients, each client having a local cache storing data downloaded via the network, the method comprising a requesting client ( 8 ) sending a request for data to the server, and the server responding by sending the requested data to the requesting client ( 8 ) or referring the requesting client ( 8 ) to a proxy server client that holds the requested data in its local cache, the requesting client ( 8 ) then downloading the requested data from the cache of the proxy server client across the network.
This first architecture is embodied in a client-server communications network including a server and a plurality of clients, each client having a local cache storing data downloaded via the network and the server having means for responding to a client that sends a data request to the server, wherein the server is adapted to send the requested data to the requesting client ( 8 ) or to refer the requesting client ( 8 ) to a proxy server client that holds the requested data in its local cache.
The server of the first architecture includes means for responding to a client that sends a data request to the server and is adapted to send the requested data to the requesting client or to refer the requesting client to a proxy server client that holds the requested data in a local cache of data downloaded via the network. The first architecture also involves a client terminal for connection to a server, or a browser for such a client terminal, including selection means for choosing between a plurality of proxy server clients if the server is unable to respond to a data request from the client within a target period or at all, and means for downloading the requested data from a chosen proxy server client.
In use of a second architecture, the invention may be defined as a method of downloading or uploading data via a client-server communications network that includes a server and a plurality of clients, each client having a local cache storing data downloaded via the network, the method comprising a requesting client broadcasting a data request over the network to the server and/or one or more other clients or connecting to at least one client whose address is on a proxy list held by the requesting client, the requesting client then downloading the requested data across the network from the cache of a proxy server client that is caching the requested data.
This second architecture is embodied in a client-server communications network including a server and a plurality of clients, each client having a local cache storing data downloaded via the network, wherein a requesting client is adapted to broadcast a data request over the network to the server and/or one or more other clients or to connect to at least one client whose address is on a proxy list held by the requesting client, and includes means for downloading the requested data across the network from the cache of a proxy server client that is caching the requested data.
The second architecture involves a client terminal for connection to a server, or a browser for such a client terminal, including selection means for choosing among a plurality of proxy server clients the proxy server client from which it will download the requested data, and means for downloading the requested data from a chosen proxy server client.
In an Internet context, the network is the Internet, the clients are user terminals running web browsers and the respective local caches are associated with the browsers on the user terminals that act as proxy server clients. The invention capitalizes upon the facts that (i) the vast majority of Internet access is done through web browsers that have become a de facto standard, such as Netscape and Microsoft Internet Explorer and (ii) those millions of web browsers cache a great deal of information about the web sites that people most often look at.
A key advantage of the invention, in preferred embodiments, is that it can be deployed and propagated among a large number of users as a plug-in for their existing browsers. So, whilst a simple module would have to be added to the server, users would not have to install completely new browsers but instead could upgrade their existing systems using simple download techniques with which most users are familiar. The invention therefore extends to software plug-ins for a client terminal or for a browser loaded on that client terminal and being programmed to adapt a terminal or a browser in accordance with the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that this invention can be more readily understood, reference will now be made, by way of example, to the accompanying drawings in which:
FIG. 1( a ) and FIG. 1( b ) are block diagrams showing existing ways in which a web page may be downloaded via the Internet, FIG. 1( a ) showing a simple client-server architecture and FIG. 1( b ) showing a variant in which a proxy server acts between the client and the server;
FIG. 2 is a block diagram showing how, in a preferred embodiment of the invention, a web page can be downloaded by one client from another client;
FIG. 3 is a block diagram showing how the bandwidths of connections between various clients can be compared;
FIG. 4 is a block diagram of a second embodiment of the invention that can be used in isolation or, preferably, as a fall-back for the preferred embodiment.
DETAILED DESCRIPTION
In the simplest existing client-server architecture of FIG. 1( a ), a client 1 such as a PC running a browser makes an HTTP request 2 for a particular downloadable file to the server 3 and the server 3 responds by sending the requested file to the client 1 . The file could, for example, be an HTML web page 4 , a .gif, .jpg or .mpg file, or other web content. Web pages will be used as an example of such files throughout the description that follows.
FIG. 1( b ) shows a variant in which a proxy server 5 acts between the client 1 and the server 3 to speed the average download time by reducing traffic connecting to the server 3 . The client 1 makes an HTTP request for a particular web page via the proxy server 5 . The proxy server 5 may have a cached copy of the requested web page as a result of a previous request for that web page. If it does, then it returns that cached web page to the client 1 , without connecting to the server 3 . If not, the proxy server 5 requests and downloads the requested web page from the server 3 , forwards it to the client 1 and advantageously keeps a copy in its cache in case a client 1 requests that page in the future.
In both of the above variants, the client 1 may cache a downloaded web page so that if a user requests the same page in future, it is not necessary to download that web page again from either a server 3 or a proxy server 5 . However, the user may set the browser so that when a web page in cache is requested, the cached web page is compared to the corresponding web page then available from the server 3 or the proxy server 5 . If there is a difference between the ostensibly corresponding web pages, the latest version of the web page can be downloaded, displayed and cached in place of the previous version.
Referring now to FIG. 2 which illustrates a preferred embodiment of the invention, two clients, Client A and Client B, can access a server 3 via the Internet. There would of course be many more clients in practice, but just two clients are necessary to illustrate the broad inventive concept. Both Client A and Client B run browsers that have been enhanced in accordance with the invention, preferably by downloading and executing a suitable plug-in on the respective client terminals.
In the manner of the prior art, each respective terminal of Client A and Client B holds web pages in cache as a result of previous downloads. However, by virtue of the invention, the enhanced browsers open the caches of their respective client terminals for access by other network users. So, as the client terminals can act like proxy servers, the entire network can offer faster and more reliable downloads. In effect, the invention creates a network in which there are almost as many proxy servers as there are clients. These clients that emulate proxy servers will be referred to herein as proxy server clients.
In the embodiment of FIG. 2 , each proxy server client reports its cached web pages to the server 3 so that the server 3 can store in a look-up table the client location(s) at which a particular web page is cached. In use, a user at Client A requests a web page from the server 3 with an HTTP request in the usual way. The server 3 either fulfils that request or, if it cannot fulfil the request quickly enough, looks up where else that web page is cached and responds to Client A with a short acknowledgement that points the browser of Client A to the appropriate proxy server client location. As will be explained, the acknowledgement to the requesting client can be little more than a list of IP addresses constituting a proxy list of clients to identify the proxy server client terminal(s) at which the requested web page is cached.
If the server 3 tells Client A that the web page requested by Client A is cached at Client B, then Client A contacts Client B and downloads that web page from the cache in the client terminal of Client B. Preferably, however, Client A firstly assesses and compares the bandwidths available at that time in the connections between itself and the server 3 on the one hand and between itself and Client B on the other hand. The aim is to determine which of the available connections would be the faster to use, and then to select that connection so as to minimize download times and maximize the efficient use of network resources.
In FIG. 2 , the bandwidth available between Client A and Client B has been assessed as being greater than the bandwidth available between Client A and the server 3 , so Client A requests the desired web page from the cache of Client B. However, if the bandwidth comparison was instead in favor of the connection between Client A and the server 3 , that connection would be used to download the web page from the server 3 instead of from Client B.
By extension, the technique of comparing bandwidths can be applied to the connections between Client A and proxy server clients other than Client B. So, if the desired web page is cached at other network resources such as other clients, the web page can be downloaded from one of those other resources if it would be more efficient, bandwidth-wise, to do so than to download the same web page from either Client B or the server 3 .
The principle of resource selection is shown in FIG. 3 , in which Client A has received a proxy list 6 of client IP addresses 7 from the server and then assesses the speed of the connection to each of the proxy server clients identified by the proxy list 6 . This is done by a simple PING (Packet INternet Groper) operation that attempts to contact each specified IP address 7 and returns the times taken to connect to the terminals at those addresses 7 . Specifically, a PING utility sends a packet to each IP address 7 and waits for, and times, the reply from each address 7 . It will be noted that Client A performs the PING operation rather than the server 3 because it is the connections between respective clients that matter in this context, not the connections between the server 3 and its clients.
The response times from each pinged proxy server client are recorded by Client A so that, once an appropriate number of proxy server clients have been pinged, Client A can compare the recorded response times and select the proxy server client with the fastest response for the purpose of downloading the desired web page. It is also possible for a target response time to be set and for Client A to select from the first pinged proxy server client to meet that target. This saves Client A continuing the process of pinging all of the proxy server clients on the proxy list when it has already found a proxy server client whose response time meets the target and so is deemed to be adequate.
It will be apparent that the pinging process set out in FIG. 3 is preceded by an assessment of whether it is faster to download the desired web page directly from the server 3 or to download from one of the proxy server clients that are caching the desired web page. This assessment can be done in various ways. In a first technique, for example, the server 3 may initially attempt to respond with the desired web page but if it cannot respond within a predetermined period deemed to be acceptably quick, it instead responds with the aforementioned proxy list and leaves the requesting client to find and download the desired web page from another client. This has the advantage that if the server 3 can respond and upload the desired web page to the requesting client quickly enough, there is no need to go through the delay of pinging other clients at which the desired web page is cached.
The predetermined period in which the server 3 is challenged to respond need not be a fixed period of time: that period could change dynamically in accordance with the average download time for the requesting client terminal concerned. Clearly, all else being equal, a client terminal connected to the Internet via an ordinary 56 k modem will expect slower downloads than a terminal using a modem that can exploit a 128 k ISDN or ADSL connection. In those circumstances, it is appropriate that the server 3 senses the speed of the connection from the requesting client and responds to the sensed speed by tailoring the predetermined period accordingly Specifically, the server 3 should shorten the predetermined period when the connection is relatively fast, and should lengthen that period when the connection is relatively slow.
A second technique for assessing the speed of server response involves the server 3 invariably and immediately responding to web page requests with a proxy list 6 but including in that proxy list 6 the IP address of the server 3 itself. As a result, the server 3 is treated like the other resources (i.e. proxy server clients) identified by the proxy list 6 and so will be pinged along with the proxy server clients identified by that list. If the server 3 happens to be the fastest resource to respond, or if it is the first resource to respond within a predetermined target time, then the desired web page is downloaded from the server 3 . Otherwise, the desired web page is downloaded from a proxy server client whose response is found to be fastest among the various resources identified by the proxy list 6 or whose response time is the first to meet the target.
This second assessment technique is currently less preferred than the first assessment technique because although it is more elegant in terms of architecture, it incurs the overhead of downloading the proxy list 6 from the server 3 and then pinging the IP addresses 7 on that list.
The various proxy server client locations, expressed as their respective IP addresses, can be stored on the server 3 as simple text files and a proxy list file is associated with every web page in the look-up table held on the server. The size of the proxy list file should obviously be kept within reasonable bounds, for example limited to a maximum of twenty IP addresses for each web page. This is due to considerations of memory capacity and download time but also has implications for efficient bandwidth assessment, in which it is desirable not to ping too many client terminals.
Another approach of the invention is shown in FIG. 4 , in which a client 8 making a web page request holds a proxy list of IP addresses defining a server 3 and also a group of other clients 9 . The request is made to the IP addresses in the proxy list, so being made to the server 3 in the normal way but also being broadcast to the group of other proxy server clients 9 , to inquire as to whether they hold any of the requested information in cache. If they do, they can report back to the requesting client 8 and the web page can then be downloaded by that client 8 from any of the proxy server clients 9 that are caching the requested web page. Each of the client terminals on the proxy list may in turn be connected to other proxy server client terminals 10 to which they can forward the request, thus forming the chain or tree structure shown in simplified form in FIG. 4 .
In the FIG. 4 approach, the server 3 is not relied upon to return a list of proxy terminals. The requesting client terminal merely needs to have the IP address of one, or the IP addresses of a few, of the proxy server client terminals 9 for the chain or tree to begin. The necessary IP address(es) could be downloaded from a web site or distributed with software.
It would also be possible to broadcast a short request over the network to make an initial connection with a proxy server client terminal 9 that has the requested web page in cache and responds to the broadcast. This operation would only need to be performed once since the IP address of the responding proxy server client terminal could then be stored by the requesting client terminal for later use.
An advantage of the approach of FIG. 4 is that it is possible to find web pages even when the server 3 is down. It could thus be a fall-back to the architecture of FIG. 2 , to be used only when there is no response from the original server in operation of the FIG. 2 embodiment.
If appropriate, the choice between potential proxy server client sources 9 of the cached web page can be made after the above-mentioned bandwidth comparison between the various connections to those proxy server clients 9 . As before, this involves pinging all the proxy server client terminals 9 on the proxy list, including the server 3 , and downloading via the fastest connection.
Again, a decision is required about whether to ping each IP address on the proxy list held by the requesting client 8 , or simply to download the web page from the server 3 . If the FIG. 4 architecture is used as a fall back, then a timeout can be set so that if no response has been received from the server 3 after a predetermined (but not necessarily fixed) period of time, then the chain or tree process is followed.
Another issue with pinging through a chain or tree structure is that each proxy server client terminal 9 at each level of the structure will ping to proxy server client terminals 10 in the next level of the structure. So, the originally-requesting client terminal 8 will not necessarily ping directly to the potential source of the requested web page if that source is more than one level down the structure. In those circumstances, it is necessary to add another step into the process to check the speed between the originally-requesting client terminal 8 and the potential source 10 A, as shown in FIG. 4 , to be sure that there is a fast connection for downloading from the potential source 10 A.
In all cases, a client advantageously reports to the server 3 upon downloading and caching a web page retrieved from cache among proxy server clients. In this way, the server can add that proxy server client location to its look-up table as a further potential source of that web page. It is similarly advantageous that a proxy server client reports to the server 3 removal of a web page from its cache, for example during a routine automated cache clean-up or in response to a user command. The server 3 can therefore delete that web page location from its look-up table and so knows to point requesting clients elsewhere if they request the deleted web page.
The invention requires extra messaging but it is expected that, in most practical cases, the overhead of that extra messaging in terms of download time would still allow shorter aggregate download times than can be achieved directly from the server.
The inventors recognize the need to ensure that no proxy server clients are overloaded with incoming requests, broadcasts and the resulting uploads, as this would unacceptably reduce the bandwidth available to those clients for other, unrelated communications. Accordingly, the invention contemplates means for monitoring the proxy workload of proxy server clients and preventing overload. This can be achieved at the client end by refusing to serve certain requests over a specified workload limit, and/or at the server end by omitting an overloaded proxy server client from the proxy lists sent in response to requests from other clients. Also, in the embodiment of FIG. 4 , the invention contemplates limiting the number of proxy server clients in the group of clients that are polled and, possibly, changing the members of that group from request to request.
Many other variations are possible within the inventive concept. For example, the server in the FIG. 2 embodiment can periodically update the look-up table from which the proxy lists are derived so to ensure that the lists are optimal. This can be achieved by pinging the IP addresses in the table from time to time, comparing their response times and discarding the slowest for a given item of data or those that fail to meet a target threshold. A possible problem with this approach is that the connection between a server and a proxy server client does not equate to the connection between one client and another client, so the server is not always best placed to assess client-client bandwidth. Another and possibly better approach is that when a client reports to the server upon downloading and caching a web page received from a resource such as a proxy server client, that client tells the server the IP address of the proxy server client that provided the web page. The server can therefore assemble a list of the most commonly accessed and hence fastest resources and can discard the less commonly accessed and hence slowest resources, like a voting scheme in which only those resources proven by various requesting clients to be fastest will continue to survive in the proxy lists held by the server.
The present invention may be embodied in other specific forms without departing from its essential attributes. Accordingly, reference should be made to the appended claims rather than to the foregoing specific description as indicating the scope of the invention. | A method of downloading or uploading data via a client-server communications network, which network comprises a plurality of clients (A, B, 8, 9, 10 ) each having a local cache storing data downloaded via the network. The method comprises responding to a data request made to the network by a first client (A, 8 ) by uploading data from the cache of a second client (B, 9, 10 ) and transmitting that data across the network to the first client (A, 8 ). Also disclosed are client-server networks operating in accordance with the method and to the related servers ( 3 ), client terminals (A, B, 8, 9, 10 ), browsers loaded on client terminals, and plug-ins for such terminals and browsers. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of Ser. No. 13/659,774, filed Oct. 24, 2012, pending, which claims the benefit of provisional applications Ser. No. 61/551,388 to Jeffery et al., entitled “Using a Mobile Phone With Integrated Motion Sensing For Evaluation of Sports Motions and Providing Customized Sports Instructions Responsive to Said Evaluation,” filed on Oct. 25, 2011; and Ser. No. 61/713,813, to Jeffery et al., entitled “Method to Analyze Sports Motions Using Multiple Sensor Information From a Mobile Device,” filed on Oct. 15, 2012; each of which is incorporated herein by reference. This application is also related to U.S. patent application Ser. No. 13/269,534, entitled “Method and System For Dynamic Assembly of Multimedia Presentation Threads,” by Mark Jeffery, filed Oct. 7, 2011; and U.S. patent application Ser. No. 13/655,366, entitled “Method and System To Analyze Sports Motions Using Motion Sensors of a Mobile Device,” filed Oct. 18, 2012, both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to using a mobile device with integrated motion sensing to evaluate swinging, throwing or other body motions, and dynamically providing customized sports instructions responsive to the evaluation.
[0004] 2. Description of the Related Art
[0005] Conventional sports instruction typically comes in one of three forms. The first is by book or video, written or recorded by a sports professional, explaining proper form, how to correct errors, and how to improve performance, etc. The student has access to a library of content as either chapters in the book or static lessons delivered via the web or on DVD, but he or she then needs to determine which lessons to take, what order to take them and what to focus on. These media may come with a survey that leads the student to lessons they may find valuable, but these lessons often require the student to have some understanding of his or her specific errors.
[0006] Golflplan with Paul Azinger is a good example of this approach. The Golfplan iPhone, iPad and Android apps include an initial survey which asks questions and the user then has access to a database of videos which are presented in an order responsive to the survey inputs. These videos are static however, and do not change in sequence unless the user re-takes the initial survey.
[0007] The second form of sports instruction is through an in-person lesson with an instructor who determines an athlete's errors by observing the student and/or by using video analysis technology. The instructor then uses their “expert” knowledge to interpret the student's motion errors, demonstrate proper motion, and give the student a practice regimen to perfect his or her form.
[0008] The third is highly technical and utilizes more sophisticated analysis of swing data recorded by one of a few technologies. Here a student may attach dedicated hardware motion-sensing devices to their club, racquet, and/or body. Specialized software then analyzes the motion data, typically on a personal computer. An example of such an approach is disclosed in U.S. Published Patent Application No. 2005/0054457 to Eyestone et al. which is assigned to SmartSwing, Inc. Users can also go to motion capture laboratories equipped with computer vision systems that track the motion of a swing and ball flight in two or three dimensions. Technical analysis of swing data can tell a user with great accuracy not only what their errors are but also to what degree they suffer from them. Furthermore, the motion capture analysis data can be utilized for custom fitting of the sports equipment, such as golf clubs and tennis racquets.
[0009] Of these three conventional forms, the first including books or video lessons, is the most accessible and lowest cost. The second method of in-person instructor lessons is less convenient and has moderate cost, and the third is often used when an athlete becomes more serious about improving performance and is the highest cost.
SUMMARY OF THE INVENTION
[0010] One aspect of the disclosure relates to a method, comprising moving a mobile device having motion sensors integrated therein to simulate a sports motion; evaluating the simulated sports motion to determine at least one topic of interest; selecting, from a content database, content associated with the topic; and displaying the selected content on the mobile device. The motion sensors can include a gyroscope and an accelerometer. In an embodiment, the step of evaluating the simulated sports motions includes evaluating pitch, roll, and yaw of the mobile device. The selected content can include a video clip of an instructor providing swing improvement information, text related to the evaluation of the sports motion, an animation of a proper sports motion, etc. In an embodiment, the method is performed by a processor integral to the mobile device. In an embodiment, the mobile device is held by a user while being moved to simulate the sports motion.
[0011] According to another aspect of the disclosure, an apparatus comprises a mobile device having motion sensors integrated therein, the apparatus including a non-transitory computer-readable medium which stores a set of instructions which when executed by a processor of the mobile device performs the steps of the method described above.
[0012] According to another aspect of the disclosure, a system comprises a server; a content database linked to the server; and a plurality of mobile devices linked to the server, each of the mobile devices having motion sensors integrated therein; wherein when one of the mobile devices is moved to simulate a sports motion, the sports motion is evaluated to determine at least one topic; a presentation snippet is assembled from content retrieved from the content database; and the presentation snippet is displayed. In an embodiment, the mobile devices are linked to the server via the Internet. In an embodiment, a first one of the mobile devices can be used to simulate a first sport and a second one of the mobile devices is used to simulate a second sport, the first sport and the second sport being different sports. For example, the first one of the mobile devices might be used to evaluate golf swings while the second one of the mobile devices might be used to evaluate baseball swings, the mobile devices connected to the server concurrently. In an embodiment, the presentation snippet is displayed on the same mobile device used to simulate the sports motion. Alternatively, the presentation snippet could be displayed on a display device different from the mobile device used to simulate the sports motion, such as a web-enabled television.
[0013] According to another aspect of the disclosure, a method of analyzing sports motions comprises determining a starting point of a sports motion to be simulated using a mobile device having integrated motion sensors; moving the mobile device from the starting point along a path to complete the simulation;
[0014] obtaining motion data from the motion sensors relating to the starting point and the movement along the path; determining an occurrence of a simulated sports event using the obtained motion data; evaluating the simulated sports motion to determine at least one topic of interest; selecting, from a content database, content associated with the topic; and displaying the selected content on the mobile device or other web enabled display device. In an embodiment, the mobile device is not attached to any piece of sports equipment and the starting point is indicated by the mobile device being held still for a predetermined length of time.
[0015] In an embodiment, the sports event is an impact point with a virtual object (e.g., a virtual golf club with a virtual golf ball) The method can further include determining the velocity of the virtual object around the impact point. The velocity can be determined at least in part on velocity of the mobile device around the impact point, arm length, club length, and arc length for the swing type. In an embodiment, velocity is obtained without using data from an accelerometer. Furthermore, determining the velocity can include applying a multiplier based on estimated wrist hinge and forearm rotation as measured by yaw and roll of the mobile device at the impact point. Once velocity is determined, ball flight distance can be determined based at least in part on the determined velocity of the virtual object. In an embodiment, determining the occurrence of the simulated sports event using the obtained motion data includes analyzing the pitch of the mobile device during the simulated sports motion. Determining the occurrence of the simulated sports event can involve analyzing the roll of the mobile device at an impact point, such as by subtracting roll data at the impact point from roll data from the starting point.
[0016] In an embodiment, the sports event is an impact point. The impact point can include the impact of a virtual golf club, tennis racquet, baseball bat, ping pong paddle, lacrosse stick, badminton, squash or racquet ball racquet.
[0017] In an embodiment, the sports event is a release point. The release point can include a release point of a bowling ball, a lacrosse handle, a basketball, a baseball, a hockey stick, a bean bag, an American football and a fishing rod.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1( a ) illustrates a block diagram showing the architecture of a mobile device useable in conjunction with the present invention;
[0019] FIG. 1( b ) illustrates an exterior view of the mobile device;
[0020] FIG. 2 illustrates types of rotational movement of a mobile device;
[0021] FIG. 3 illustrates an exemplary system for dynamic assembly of custom lessons responsive to motions of a mobile device, according to an embodiment of the present invention;
[0022] FIG. 4 illustrates an exemplary system for dynamic assembly of custom lessons in a Web-based environment;
[0023] FIG. 5 illustrates several exemplary sports with splash pages initially displayed on a user's mobile device, as well as a list of potential lessons under each;
[0024] FIG. 6 illustrates an exemplary system for dynamic assembly of custom lessons for different users simultaneously in a Web-based environment, according to another embodiment of the present invention;
[0025] FIG. 7 illustrates an example of a preferred embodiment of a golf lesson, whereby the user takes swings of the mobile device and is graded on their swing speed and accuracy;
[0026] FIG. 8 illustrates customized lessons for face control and swing speed responsive to the motion sensor input;
[0027] FIG. 9 illustrates a phone-in-hand exercise wherein the user sits in a chair and is asked to take five hooks, five slices and five straight swings;
[0028] FIGS. 10( a ) and 10( b ) illustrate the pitch and roll of the mobile device during an example full golf swing useful for determining swing accuracy;
[0029] FIGS. 11( a ) and 11( b ) illustrate use of pitch data of the mobile device to determine the impact point and the speed of the club head through the impact point;
[0030] FIGS. 12( a ) to 12( c ) illustrate yaw, roll and pitch for a baseball swing;
[0031] FIGS. 13( a ) to 13( c ) illustrate pitch and roll for a bowling motion; and
[0032] FIGS. 14( a ) and 14( b ) illustrate an example mobile device holder mounted to an ancillary device.
DETAILED DESCRIPTION OF THE INVENTION
[0033] For clarity and consistency, the following definitions are provided for use herein:
[0034] As used herein, a mobile device refers to a hand-held device having a microprocessor, memory, and integrated motion sensors.
[0035] As used herein, a display device refers to any Internet connected display capable of graphically displaying a web page.
[0036] As used herein, a presentation snippet is a component of a multimedia presentation, such a video clip, an animation, a survey, a text message, an audio recording, a hologram and/or any other media content, or a combination thereof.
[0037] As used herein, a lesson node is a node of a lesson thread representing at least one presentation snippet.
[0038] As used herein, a custom lesson includes the sequence of lesson nodes of a lesson thread, comprising customized multi-media instruction content for a particular user.
[0039] As used herein, a calibration point refers to the location in time and space of the mobile device in a set-up position prior to the start of the sports motion.
[0040] As used herein, an impact point refers to the location in time and space of impact with a virtual object.
[0041] As used herein, a release point refers to the location in time and space of release of a virtual object.
[0042] Referring to FIG. 1( a ) , an exemplary mobile device 160 useable in conjunction with the present invention is illustrated. For illustrative purposes only, the following discussion describes the device 160 in terms of an Apple iPhone available at the time of filing. However, it is to be understood that the discussion is applicable to other mobile phones with motion sensors (e.g., Samsung Galaxy III smart phone), as well as other mobile devices with computing capabilities having motion sensors (e.g., Apple iPod Touch) existing today or later developed. Furthermore, it is to be understood that over time, device capabilities will increase. Indeed, under Moore's Law, the number of transistors that can be placed on an integrated circuit has doubled approximately every two years and this trend is expected to continue for the foreseeable future. Accordingly, it is to be understood that the mobile device 160 described herein is merely meant to provide an example as to how the present invention may be implemented at the current time.
[0043] As shown in FIG. 1( a ) , the exemplary mobile device 160 is an Apple iPhone 4S which includes a communication interface 301 , a processor 303 , motion sensors 304 , a memory 305 , and a power supply 307 . The communication interface 301 controls various input/output devices including a digital camera, a 30-pin dock connector port, a headphone jack, and a built-in speaker and microphone. The communication interface 301 also includes a touchscreen 308 , shown in FIG. 1( b ) . The processor 303 is a dual core Apple A5 processor which has a system-on-a-chip (SOC) architecture that integrates the main processor, graphics silicon, and other functions such as a memory controller. The motion sensors 304 can include a three-axis gyroscope to measure a rate of rotation around a particular axis and an accelerometer to measure acceleration in three dimensions X, Y and Z. The memory 305 includes 16 GB, 32 GB, or 64 GB of flash memory (depending on the model). The memory 305 includes storage for an application 306 (“app”) which includes the software of the invention. The power supply 307 includes a rechargeable lithium-polymer battery and power charger.
[0044] FIG. 2 illustrates the various types of rotational movement measured by the motion sensors 304 of the mobile device 160 . These sensors 304 include the accelerometer to capture X, Y and Z acceleration data (expressed in G's along a respective axis), and the gyroscope to measure pitch, roll and yaw of the mobile device 160 as it moves (expressed in radians with respect to a respective axis). At present, the motion sensors sample at about 100 times per second (100 hertz), with this data made available (by either polling or having the data pushed) to the application 306 loaded on the mobile device 10 . A representative gyroscope useable in conjunction with the present invention is the L3G4200D gyroscope made by STMicroelectronics, Inc. However, it is to be understood that the present invention is not limited to motion sensor technology currently available.
[0045] Referring to FIG. 3 , an exemplary system for dynamic assembly of custom lessons 100 is illustrated. The system for dynamic assembly of custom lessons 100 includes a dynamic lesson generator 120 that, responsive to the mobile device swing or other motion analysis inputs 105 and/or analytics/external data 130 (e.g., demographic information, historical swing or other motion data for the user, customer behavior, and preference information), applies a set of rules 125 to generate each of a plurality of presentation lesson nodes, each node consisting of singular or plural snippets, which can be traversed in an order forming a custom lesson 110 .
[0046] The generated custom lesson 110 can include customized information; thereby creating a multimedia presentation tailored to a particular user responsive to analysis of the user's simulated sports motion captured by the motion sensors 304 of the mobile device 160 . The dynamic lesson generator 120 can be a standalone application stored in, and executed using, a single mobile device or implemented on one or more servers accessible by one or more client devices. In an embodiment, the dynamic lesson generator 120 is configured to generate a plurality of custom lessons 110 concurrently, each for one of a plurality of users.
[0047] As a user traverses the customized lesson 110 , the dynamic lesson generator 120 generates the next lesson node of the customized lesson 110 . At each lesson node, at least one presentation snippet, assembled using content 135 from a content database 140 , is outputted to the user. The content database 140 can include any organized collection of media files (e.g., text files, audio files, video files). In an embodiment, a plurality of lesson snippet content 135 , such as animated simulations and multiple video clips may be assembled into a lesson node, and displayed simultaneously, or in sequence. In an embodiment, the selection, assembly, and ordering depend on the set of rules 125 as well as the capabilities of the user device. In an embodiment, the dynamic lesson generator 120 assembles each presentation snippet from content elements selected from the content database 140 “on the fly” as the user traverses the customized lesson 110 . However, in other embodiments, the presentation snippets are pre-assembled, and the pre-assembled presentation snippets are selected from the content database (e.g., as HTML files or video clips). Preferably, the rules 125 are maintained in a separate module, file, or database and can be modified by changing (or replacing) the module, file, or database fields without requiring any change to another component. However, in an embodiment, the rules 125 can be “hard coded” within the application logic.
[0048] The techniques of the present invention described herein (e.g., use of the dynamic lesson generator 120 to generate a customized lesson 110 ) can be accomplished by loading an appropriate application 306 into the memory 305 and executing the application 306 . Where the device 160 is the Apple iPhone, the user inputs 105 are received via the user moving the mobile device in a simulated sports motion 306 and interacting with the touch screen 308 , and the generated lesson thread 110 can be presented to the user by way of the same touchscreen 306 (and speakers), for example.
[0049] An application 306 for the Apple iPhone can be developed using the Apple Developer Suite, including use of Xcode, Interface Builder, and iPhone Simulator development tools, or via custom programming in Objective C. Furthermore, the Apple “Media Player” framework can be used to provide media playback capabilities for the mobile device 160 . Apple supports at least the following codecs: H.264 Baseline Profile 3, MPEG-4 Part 2 video in .mov, .m4v, .mpv, or .mp4 containers, as well as AAAC-LC and MP3 formats (for audio). The content database 140 described herein can include a folder (or set of folders) including a collection of media files in supported formats. The media files can exist in the memory 305 or an external server addressable by a URL, for example. For further information regarding programming for the Apple iPhone, see, Beginning iOS 5 Application Development, by Wei-Meng Lee (John Wiley & Sons, Inc.), ISBN 978-1-118-14425-1, which is incorporated herein by reference in its entirety. It is to be understood that where the mobile device 160 is other than the Apple iPhone other programming techniques and tools can be used. For example, where the mobile device 160 is a mobile device such as a smartphone or tablet computer utilizing the Android operating system, an appropriate Android software development kit (SDK) can be used to provide the tools and application program interfaces (API) for developing the application 306 on the Android platform using the Java programming language.
[0050] FIG. 4 illustrates an exemplary system for dynamic assembly of custom lessons 200 , according to another embodiment of the present invention.
[0051] As shown, the mobile devices 160 and web-enabled display 165 are coupled to the Internet 150 . While a single mobile device 160 is shown in FIG. 4 , it is to be understood that many more concurrent users and devices may be supported.
[0052] Initially, the display device 165 connects to a Web site by the user linking to a URL in a browser. Then, at a presentation layer web server, device information is determined to identify the type of device and browser being used. This may be done in various known ways, such as, for example by obtaining the user-agent string passed by the browser of the device 165 which indicates which browser is being used, its version number, and the operating system and version. The device information is then used to ensure that the presentation snippets created are compliant with the device 165 . For example, where the device 165 is a desktop computer with Internet Explorer, the presentation snippets may use Adobe Flash media, but if the device 165 is an Apple iPad with the Safari browser, an alternative format would be chosen. Likewise, the presentation layer web server may determine that a mobile browser will be used. In that case, the web pages outputted to the device 165 may contain information that is easier to view on a smaller screen having a lower resolution. In an embodiment, the presentation snippets include code for display via an HTML5 enabled web browser. HTML5 allows rich multimedia content display on multiple platforms with features designed to make it easy to handle multimedia content without the need to resort to proprietary APIs and plugins.
[0053] Additionally, a user-ID can be used to track the user. For an existing user, the user-ID can be provided by the user through an authentication process upon user log-in. New users can be assigned a unique user-ID, such as their email address, and select a password, for example. Furthermore, a thread-ID can be assigned for the particular session for the generated custom lesson 110 . Other user information (e.g., demographics, purchase history, preferences, etc.) may also be obtained from various sources, e.g., the analytics/external databases 130 , and may be combined with motion data history.
[0054] As the user traverses the custom lesson 110 , the dynamic lesson generator 120 keeps track of the user's position (current thread node), and generates/selects a presentation snippet associated with the current thread node for display on the user's device 160 and/or the display device 165 , where it is presented to the user. User inputs (e.g., output data from swinging the mobile device or touching the screen in response to a question) are sent from the device 160 back to the dynamic lesson generator 120 .
[0055] It is to be understood that the dynamic lesson generator 120 includes a computer system and software of the invention stored in memory. In the embodiment illustrated in FIG. 4 , the computer system can include a central processor, memory (RAM, ROM, etc.), fixed and removable code storage devices (hard drive, floppy drive, CD, DVD, memory stick, etc.), input/output devices (keyboards, display monitors, pointing devices, printers, etc.), and communication devices (Ethernet cards, WiFi cards, modems, etc.). Typical requirements for the computer system include at least one server with at least an INTEL PENTIUM III processor; at least 1 GB RAM; 50 MB available disc space; and a suitable operating system installed, such as LINUX, or WINDOWS 2000, XP, Vista, Windows 7 or 8 by Microsoft Corporation. Representative hardware that may be used in conjunction with the software of the present invention includes the POWER EDGE line of servers by Dell, Inc., the SYSTEM X enterprise servers by IBM, Inc., PROLIANT or INTEGRITY line of servers by Hewlett-Packard, and the SPARC line of servers by Oracle Corporation (formerly Sun Microsystems). The software to accomplish the methods described herein may be stored on a non-transitory, computer-readable medium and may also be transmitted as an information signal, such as for download. The content database 140 can include any computer data storage system, but, preferably, is a relational database organized into logically-related records. Preferably, the content database 140 is an enhanced relational database such as the IBM DB2 Universal Database using IBM's Audio, Image, and Video (AIV) Extenders, to support various media files, or the Oracle InterMedia product which enables an Oracle database to store, manage, and retrieve images, audio, video, in an integrated fashion.
[0056] It is to be understood that although not illustrated, the analytics databases 130 can be accessed from external sources each of which have their own computers with central processors, memory (RAM, ROM, etc.), fixed and removable code storage devices (hard drive, floppy drive, CD, DVD, memory stick, etc.), input/output devices (keyboards, display monitors, pointing devices, printers, etc.), and communication devices (Ethernet cards, WiFi cards, modems, etc.). Alternatively, the analytics databases 130 and the content database 140 can be implemented on the same physical computer system.
[0057] The analytics databases 130 includes a motion database such that the dynamic lesson generator stores each motion in the system 100 . These data can be used for longitudinal tracking of user improvement on various dimensions, and for customizing lesson content responsive to the swing motion history.
[0058] Although the Internet 150 is depicted as being used for communication among the illustrated entities, it is to be understood that other network elements could, alternatively, or in addition, be used. These include any combination of wide area networks, local area networks, public switched telephone networks, wireless or wired networks, intranets, or any other distributed processing network or system.
[0059] Referring to FIGS. 5 to 9 , the present invention will be further clarified by examples of sports lessons implemented using techniques described herein, according to an embodiment of the present invention. FIG. 5 illustrates three different splash screens on a mobile device for lessons in golf, baseball, and tennis. FIG. 6 is an embodiment of the web-based method of FIG. 4 for golf, baseball, and tennis sports lessons. In the specific example, FIGS. 7 to 9 , the sports lesson is useful for learning how to play golf.
[0060] To facilitate understanding, each application is divided into two separate sections. The first is the practice environment where, for example, the user enters a virtual driving range (in the case of golf instruction), batting cage/pitching mound (in the case of baseball instruction), tennis court (in the case of tennis instruction), ski run etc. For impact sports the users hold the mobile device 160 in their hand as a club, bat, ball, or racquet, for release sports the user simulates an actual swing or throw or the user may attach the phone to their leg or arm in a holder as in the case of skiing or boxing respectively, for example. Data gathered by the device's internal gyroscope, accelerometer, and other sensors (such as the compass or Assisted Global Positioning System, AGPS) is then analyzed and relevant feedback (swing speed, orientation, acceleration, estimated ball flight path/distance) is given. Users can enter the practice environment on their mobile devices, and see ball flight following each swing, for example, or can also connect to a web-based version built in HTML, CSS, and Javascript from their personal computer, web-enabled TV or tablet computer.
[0061] Using a login/password, users can access an individual practice area. Once inside a personal identification number (PIN) can be shared with friends, or a Uniform Resource Locator (URL) inviting them to download the app and join a shared driving range, batting cage etc. In another embodiment users can see ‘friends’ who are already logged into the system and can select them from a menu and request they join the individual practice area.
[0062] The distributed application is accomplished using a comet (aka Ajax Push, HTTP server push) application that allows the iPhone (or other smartphone or iPod Touch) to push swing data to the browser. As a student practices in the virtual practice facility their swing data is added to a cloud-based database where it is accessible at a later “scoring” section of the app.
[0063] Once the user has spent some time in the virtual practice environment and the application has found a baseline for the user's motion the App will alert the user via a “tips pop up” where a professional instructor will appear. The virtual instructor will then tell the user what their most impactful error is and provide a quick tip on how to begin fixing it. If interested, the user can follow the instructor into the second section of each App where he or she can take virtual lessons with a top sports instructor. In the networked embodiment, the ‘expert’ instruction may appear on the Web enabled device 165 , instead of the smart phone 160 .
[0064] The lesson portion of the system comprises three major components, as previously summarized in FIG. 3 : (1) the content database 140 , (2) the motion analysis engine 105 , and (3) the dynamic lesson generator 120 (including the rules engine 125 ). The content database 140 can include, but is not limited to, short videos of various instructors discussing elements of various techniques, audio clips, text, 3-D animations and exercises. These elements are the presentation snippets. The motion analysis engine 105 has as inputs the X, Y and Z acceleration from the accelerometer (a x , a y and a z respectively) and pitch, yaw and roll of the gyroscope in the smart phone. The motion analysis engine 105 takes the accelerometer and gyroscope data and outputs sport specific variables that are input to the rules engine 125 . In coordination with the rules engine 125 , the dynamic lesson 120 , applying the rules engine creates a customized dynamic lesson (called a presentation thread) for a specific user, which is assembled from the content database to form the presentation snippets. The content is highly customized, and is changed dynamically as the user interacts with the system, following teachings of U.S. patent application Ser. No. 13/269,534. As illustrated in FIG. 6 multiple lessons, in the same or different sports, may be delivered simultaneously and on different web enabled display devices 165 , the user positioned so as to be able to view the display for their specific lesson.
[0065] Golf School
[0066] Referring to FIGS. 7 to 9 , the present invention will be further clarified by the following example of a Golf School implemented using techniques described herein, according to an embodiment of the present invention. FIG. 7 illustrates an exemplary sequence of lesson videos, demos, and drills. These figures and the related methods for motion analysis are described in detail herein.
[0067] In an embodiment, the Golf School application for the iPhone includes a virtual driving range and a series of lessons on subjects such as the driver, irons, wedges, putting, sand shots etc. The standard driving range is a ‘Free’ downloadable App where the user can hit only the driver on a basic range. An upgraded driving range is available however, where the user can swipe left or right to choose the specific hole they would like to play and select the specific club they would like to use for the shot. As the user swings the phone held in their hand, their swing is analyzed and the ball flight is animated on the screen of the phone. Additional data is also displayed on the phone screen including, but not limited to, the angle of the phone at impact translated to hook or slice, the calculated speed of the golf club, and the distance a golf ball would travel in yards.
[0068] In another preferred embodiment, the user's Golf School phone application is connected to a server where the user has a unique account and identifier. This networked configuration enables the user to swing the phone and see the ball flight and related data on any other web enabled device such as an iPad, PC, or Web-enabled television, see FIG. 4 and FIG. 6 . That is, as the user swings the phone the ball flight is animated on a different display, preferably viewable by the user. Furthermore, the user can invite friends to join the practice session on the range, where different players balls are color coded and labeled by the players name or avatar; these friends maybe in the same geographic location or in different geographies simultaneously.
[0069] For the golf driver lesson, the value proposition to the user is ‘Add twenty five yards to you drive.’ This driver lesson includes first, general instruction, including a quick video on the basics of the specific activity followed by an exportable demo that explains the golf swing motion step by step in detail, with graphical overlay of the correct positions of the hands and body at key points in the golf swing. In this demo, the user can zoom in and out, pause, play, reverse, scrub and play at various slow and high speeds. After the user has studied the demo he or she moves to a baseline swing section that asks him or her to take three swings for analysis (see FIG. 7 ). The user can skip this section and the system will use the data collected from the driving range, or the user can take the three swings. After the three swings are recorded the app gives the user a grade on various dimensions of the swing (generally speed and accuracy) and gives the user a recommendation on which lesson track to start with. This “scoring” section keeps track of every swing the user has ever taken so he or she can refer back to past swings and see their progress.
[0070] Once the user has chosen their lesson, he or she will view a series of video snippets and phone-in-hand exercises that focus on the specific errors he or she suffers from—for the golf driver lesson accuracy track this could be a slice or hook, in speed it could be casting, lag, improper forearm rotation, or wrist hinge, see FIG. 8 . In tennis, an accuracy error is over rotation as the forearm swings or high-low swing path, in speed it could be improper coiling and uncoiling. In baseball an accuracy error could be a swing bubble at impact due to improper forearm rotation. Whatever the sport, output of the motion analyzer is used by the rules engine to define the error(s) of the user, and the lesson is customized to fix the error(s).
[0071] During the lesson the instructor will prescribe a drill or drills to correct the specific error. The drills are varied depending on which types of feedback work best with each activity, but are designed so that the user can return to them for any amount of time convenient to their schedules. In the golf accuracy lesson for example, see FIG. 9 , a drill is to sit in a chair and hold the phone out straight from the body. They then swing the phone back and forth while rotating their forearms. This forearm rotation is intimately related to hooking or slicing the golf ball, and audio feedback is given in terms of a sound driven from the gyroscope or the expert instructor saying “good”, “good”, “hook”, “slice”, etc, for example. That is, immediate feedback is given responsive to the motion sensor input.
[0072] As another example, for the speed drill the user sits down in a chair, holds the phone out in front of himself, waits for a calibration vibration, then rotates back and then through the swing. The drill is designed to teach the user to control and accelerate their speed while maintaining a square club face. The user starts slow and each time he or she drives, through audio feedback, the instructor will tell the user whether he or she swung faster or slower than the previous swing, and how the accuracy compared to the last swing. The challenge is to slowly build speed while maintaining excellent rotation timing with a square phone (club head) at impact. If the user swings and over or under rotates, the instructor provides audio feedback that he must slow back down and try again. After the user finishes a lesson thread he or she can return to the baseline swing section to see if they can improve their scores.
[0073] Specifically, in the Golf School “Add 25 Yards To Your Drive”, lesson Mike Malaska, 2011 PGA Golf Teaching Professional, teaches via video snippets how to correct yard stealing errors in full swing drives. The thread starts with an introduction that discusses where a golfer should focus their attention, arm movements. Then Mr. Malaska goes into a driver demo where he discusses all of the stages of the swing and proper arm, forearm, and wrist positions at each stage. The user then moves to their baseline swings and scoring. Once scored by the motion analyzer, the user can go to a speed or accuracy lesson. The speed lesson is a series of two minute videos on how specifically the arms, the forearms, and the wrists each build speed individually.
[0074] The control lesson is a series of two minute videos that explain timing, and based on your swing score's error, how to correct a slice or hook with. The drill has the user sit in a chair and swing through, receiving feedback after each swing on how square he or she were at impact. Once the user understands the motion, Mr. Malaska has the user swing five hooks, then five slices, then five straight. This builds an understanding and connection between hand positions and ball fight. Once the user can consistently produce the different types of swings, Mr. Malaska has the user swing through a range, starting with a large hook (or a swing with a very closed face at impact) then moving slowly to a less closed face (draw), then a square clubface (straight), then a slightly open clubface (fade), and finally a very open club face (slice). Once the user can control, finely the face of the club at impact, he or she will be able to control where the ball goes on the fairway.
[0075] Note that these content are customized based upon the swing motion analysis and the area the user choose to focus on. For example, if the user selects accuracy as an area to focus on then the key motion analyzer variable is the roll of the phone, which is translated into degrees of hook or slice. The system then customizes the lesson so that a user who hooks will see different content to that of a user who slices. Furthermore, in a preferred embodiment additional user input can customize the thread content. For example, there is an option for the user to enter height, average driving distance, gender, and left or right handedness. So that a female golfer, who is left handed and hits the driver 200 yards may see a top female golf instructor, with videos mirrored for left handedness, and driver distances scale to an average of 200 yards.
[0076] Furthermore, the golf lessons may utilize the web-enabled display device 165 of FIGS. 4 and 6 . So that for example, with the web-enabled display device 165 positioned so that the user can see the web-enabled display device 165 , the instructor (Malaska) can show two virtual sticks (like a goal post) on the web display. Where the exercise is for users to hit virtual balls, via swinging their mobile device, left, right and straight through the sticks. In order to master this exercise, students must understand how to systematically hook, slice and hit straight shots. After two or three swings, customized lesson snippets are presented on the web enabled display responsive to the swing analysis of the student. This simulation is a virtual experience closest to having an actual instructor standing next to the student.
[0077] The Golf School contains many lessons that the user can select, downloadable for a fee. These lessons include but are not limited to: driver, irons, wedges, putting, fairway bunker shots, short game chipping, sand shots, play for the first time, and golf fitness. Furthermore, lessons are customized to different levels of proficiency so that the expert player sees different content and exercises than a beginner.
[0078] A preferred embodiment also includes a “playing lesson”. A ‘playing lesson’ enables the user to swing the phone while on the actual golf course. Customized instruction is then provided as a quick fix for errors detected by the phone in the swing. For example, perhaps the user starts to slice the golf ball while playing the game. The phone will detect the error and the expert instructor will suggest a quick fix of closing the club head (phone face) at address. The user may also take a few practice swings with their mobile device prior to each shot, and receive expert instructor feedback.
[0079] A notable aspect of our invention is the motion analyzer which uses the accelerometer and gyroscope embedded within the mobile device 160 . FIG. 10 illustrates the pitch and roll of the mobile device 160 during an example full golf swing. An important element of the present invention is the calibration of the mobile device 160 by holding the mobile device 160 still in the address position (position 1 ), see FIG. 10( a ) . The motion signature for the pitch then increases in the backswing (position 2 ) and has a local minimum at the top of the golf backswing (position 3 ). However, the minimum (position 3 ) is an artifact of the pitch motion sensor rotating more than 180 degrees. In actuality, the pitch continues to increase to a maximum, greater than 180 degrees, at the top of the backswing. However, limitations of the sensor constrain the motion signature to 0 to 180 degrees. The pitch data continues to decrease in the downswing (position 4 ), back to the impact point (position 5 ), as shown.
[0080] Accuracy Analysis
[0081] Note that at the impact point, position 5 in FIG. 10( a ) , the mobile device 160 has returned to near the initial calibration point (position 1 ), which for golf is the hand position at impact with a virtual golf ball and a local minimum. For a high speed golf swing the minimum at the impact point does not return exactly to the calibration zero due to resolution limits of the gyroscope. Determining the impact point is of vital importance because the roll of the mobile device 160 at this point defines the hook or slice of the club. In other sports, the impact point is vital in determining the hook and slice of a bat or a racquet, and/or the release point in throwing or casting sports. From the impact point, the golf swing continues through follow through, positions ( 6 ) and ( 7 ).
[0082] In summary, pitch data FIG. 10( a ) , or the rotation around the axis that cuts the mobile device 160 into top and bottom halves when looking at the screen (X-axis) (see FIG. 2 ) is the most telling data stream as a golfer moves through their swing. Impact can be found at the major minimum that approaches the starting calibration point (which is defined as “zero” by taking the average of all phone position/orientation data over the course of one second (for example) taken prior to the swing when the golfer is in their set-up position). To bring context, in a golfer's swing, pitch data rises as the golfer goes into their backswing, returns to calibration as he or she swing through impact, then rises again as he or she moves into their follow through. Impact is the pitch position that gets closest to the set-up, or calibration point.
[0083] Once impact is found, swing accuracy is determined by subtracting roll data at impact from roll data at calibration, see FIG. 10( b ) . Roll data, or the rotation around the axis that cuts the phone into left and right halves when looking at the screen (Y-axis) describes “open and closed” face positions on the club head. FIG. 10( b ) shows an expanded view of the roll data. Swings that return a negative difference mean that the user over-rotated at impact which implies a closed face at impact and a resulting draw or hook depending on the amount. Swings that return a positive difference mean that the user under-rotated at impact which implies an open face at impact and a resulting fade or slice. Swings that return a near zero value mean the club face very closely matched calibration orientation at impact and imply a straight ball flight.
[0084] Speed Analysis
[0085] Club head speed is a critical parameter for golf in defining the ball flight distance. Golf club manufacturers have empirical tables which detail the ball flight distance for golf balls hit by club heads moving at a specific swing speeds. Such tables also take into consideration the club type (e.g., driver, 5-iron, putter), the club head loft, the shaft stiffness, and other variables that impact the ball flight.
[0086] Swing speed is a complex calculation due to the mechanics of sports motions. The challenge is that the mobile device sensors 304 measure motions of the hands whereas we are interested in calculating the speed of virtual sports equipment, such as a golf club head. Extensive experiments with professional athletes were conducted using appropriately fitted sports equipment to understand how hand and arm motions translate to the motion sensor data outputs. While the analysis for golf is illustrated, it is to be appreciated that the present method is generalizable to other sports motions, such as, but not limited to, those found in the sports of baseball, tennis, bowling, basketball, American football and table tennis.
[0087] If the club is swung exactly in line with the arms, then the mobile device velocity, V, is related to the club head velocity (V club head ) by:
[0000] V club head =V× (Arm Length+Club Length)/Arm Length (1)
[0088] However, expert golf players hinge their wrist and rotate their forearms to increase the velocity of the club head through the ball. These hinging and rotating motions can dramatically increase the velocity of the club head through impact, so that Equation (1) is a gross under estimate of the golf swing speed for most golfers. It is a good for putting, however, since there is no hinging of the wrists.
[0089] FIG. 11 illustrates specifically how we calculate the speed of the mobile device 160 for a golf swing. The motion signature for the pitch of the mobile device 160 for an example full golf swing is graphically illustrated. Shown below is the corresponding sports motion with points ( 4 ), ( 5 ) and ( 6 ) in pitch data labeled on the swing. We first find the impact point in pitch data, defined as the local minimum of pitch at the bottom of the swing (point 5 ). We then look forward and back in pitch data by 60 degrees. These data points, assuming proper wrist hinging, align with positions in the swing ( 4 ) and ( 6 ). Generally, about one tenth of a second passes between these two positions, so that given the player's arm length we can find the mobile device speed 160 around impact by dividing the length of a 120 degree arc where the radius of the arc is equal to the arm length by the amount of time passed: This delivers the speed of the mobile device 160 (hand speed). A similar method can be used for chipping but with a shorter arc length of 55 degrees or less due to the reduced swing length.
[0090] It has been found, using high speed video clocking, that the driver club head speed can be as slow as 2.4 times hand speed (this is in the case of a user swinging a club with rigid arms, forearms, and wrists) or as fast as 6 times hand speed (in the case of a world class professional golfer). The difference between these two multipliers comes from the combination of forearm rotation and wrist hinge which allow golfers to force the club head to travel through a much greater arc length (sometimes even close to 180 degrees) in the time it takes the hands to travel through the 90 degrees of arc length around impact. The multiplier we choose is driven directly by gyroscope acceleration through impact on the Z and Y axis (yaw and roll) which account for wrist hinge and forearm rotation respectively.
[0091] From detailed experiments with the iPhone 4 and 4s it was found that the gyroscope is particularly accurate, so that the roll data is very good to predict hook or slice within approximately half a degree. The accelerometer data from the iPhone 4, however, is “noisy”, and is not particularly accurate over the entire golf swing, but does work well for measuring forearm rotation rate around impact. This is why we divide the swing into portions and calculate an average velocity, V, of the mobile device through impact:
[0000]
V
=
D
2
-
D
1
t
2
-
t
1
(
2
)
[0000] where D 2 −D 1 is the distance between points ( 4 ) and ( 6 ) in FIG. 11 ; and t 2 −t 1 is the time taken to cover the distance D 2 −D 1 . A shorter distance is preferred, since this enables a closer approximation of the instantaneous velocity at the impact point. However the 0.01 sec resolution of the current gyroscope requires us to use the 120 degree arc. In the future, as the sampling resolution of the gyroscope increases, a 30 degree arc or less will be preferred.
[0092] Equation (2) is an approximation of the actual instantaneous velocity of the phone, and is only a first order approximation of the speed of the golf club head, since it does not include the wrist hinge or forearm rotation described above. Via detailed experiments with a high-speed video camera we were able to find multipliers for these variables, with the result of calculating club head speed within +/−10% for a variety of swing types. From club head speed we can predict ball flight distance in ideal conditions.
[0093] We envision that the data quality output from the accelerometer will improve dramatically in future versions of iPhone or Android based phones. In an embodiment of the present invention, the velocity of a mobile device 10 (having a sufficiently accurate accelerometer) at impact is calculated by integrating the acceleration from the top of the backswing (t bs ) to the zero (t 0 ) of the mobile device:
[0000] V x =∫ t bs t 0 a x dx
[0000] V y =∫ t bs t 0 a y dy
[0000] V z =∫ t bs t 0 a z dz (3)
[0000] with the total mobile device velocity at impact:
[0000] V =√{square root over ( V x 2 +V y 2 +V z 2 )} (4)
[0000] where t 0 −t bs is the time between the minimal at the top of the back swing (t bs ) measured from the pitch data and the zero at the bottom of the swing at impact, t 0 . The integrals are calculating in the software using a fourth order Runge-Kutta algorithm. See for example, William H. Press et al, Numerical Recipes 3rd Edition: The Art of Scientific Computing, 2007.
[0094] The velocity component vectors (4) are difficult to accurately calculate with the current version of the accelerometers, since the internal accelerometer has a noisy output, hence why we currently use the average method equation (2). Data on the swing motion is presented to the user and stored, local to the app and on a server in the user's account, for longitudinal comparisons of swing consistency improvement.
[0095] Baseball Example
[0096] To illustrate the preferred embodiments where the sports motion is other than golf, we provide an example for baseball. Analysis of other sports such as, but not limited to, tennis, bowling, basketball, American football or fly fishing follow similarly. Baseball swing motion sensor data is illustrated in FIG. 12 . For a baseball swing the calibration point is a set-up position with the mobile device 160 held in both hands out in front of the body, with the thumbs pointing so as to naturally line up the mobile device (virtual bat) with a ball on a virtual tee; the hands are perpendicular to the ground. The data shown in FIG. 12 is from a professional athlete and illustrates the essential features of an optimal baseball swing motion. For the baseball sports motion, yaw is the key variable, see FIG. 12( a ) , since as the “bat” is swung through the impact point with a virtual ball, the ideal hand position is with the palms parallel to the ground, which causes a rapid change in yaw of the mobile device through impact. The yaw at the calibration point was zero; hence the impact point is when the yaw crosses zero, see FIG. 12( a ) , even though the mobile device is rotated ninety degrees relative to the calibration point. In an ideal baseball swing the roll of the bat occurs just after the impact point, see FIG. 12( b ) . In the event there is a roll maximum at the impact point, then the wrists have a tendency to lift the bat over the top of the ball, causing a ground or missed ball: this is the “swing bubble.”
[0097] The pitch and yaw of the mobile device 160 taken together provide insights into the angle of the bat through the impact point. For example, the pitch data in FIG. 12( c ) shows that the hands sloped downward at the impact point, since the pitch is negative at the impact point and does not return to zero until after the impact point, and hence the bat would have contacted the virtual ball if it were thrown below the calibration point, that is, in the lower half of the strike zone. Hence, the baseball swing motion data FIG. 12 can be input into the systems FIG. 3 or FIG. 4 and dynamic lessons generated responsive to the motion input.
[0098] Bowling Example
[0099] The examples thus far have focused on sports such that the sports motion impacts virtual objects such that the impact point and release point are in the same location in time and space: i.e hitting a golf or baseball with a golf club or baseball bat respectively. The method is not limited to these examples however, and can be applied to other sports where the release point is different from the impact point, or where there is no impact point and only a release point, or when the release point is different from the calibration point. Examples include a bowling ball throw, a baseball pitch, a basketball free throw, a bean bag toss, an American football throw, or casting of a fly fishing hook. It is to be understood that these examples are for illustration and are not limiting.
[0100] In all cases the motion signature is analyzed similar to the prior examples. As a specific example, FIG. 13 illustrates the mobile device motion sensor data for a bowling sports motion. In this example, the calibration point is the hand at rest, relaxed and fully extended at the player's side, with the palm of the hand facing forward. The bowling motion is to first bring the virtual bowling ball up to the chin, cradled in both hands, and then to swing down and forwards while taking a few steps. The pitch data illustrates how the pitch of the mobile device 160 increases as the mobile device 160 is brought up to the chin, where there is a local minimum as the player starts to step forward. Then, the pitch decreases as the player swings down in the backswing motion, where there is a zero of pitch corresponding to the initial calibration zero, and then the motion transitions to the final downswings to a second zero, which is the release point of the virtual bowling ball.
[0101] Similar to the golf swing described previously, the velocity of the virtual bowling ball can be calculated from Eq. (2) and the time difference between 30 or 60 degree pitch points, similar to FIG. 11 , or via integrating Eq.'s (3). The rate of change of the roll data, the derivative of roll, through the release point is proportional to the spin rate imparted to the virtual bowling ball. Hence we can calculate the velocity and spin of the virtual bowling ball at the release point.
[0102] Note in this example the release point is different in space from the calibration point, and the impact point is further removed from the release point. In this example, the impact point occurs in virtual space. Using a cloud-based system described previously for golf, see FIG. 4 , the bowling ball can be displayed on a virtual bowling lane on an HTML5 web-enabled display, such as a web TV, and the impact with the pins simulated in time and space given the velocity and spin of the virtual bowling ball, and the length of the virtual bowling lane. Hence, the player executes the virtual bowling motion, and sees the virtual bowling ball go down the lane and hit the pins on the Web-enabled display, with a path and speed determined by the velocity and spin calculated from the swing signature of the mobile device and synchronized in time to appear like a continuous motion. Lesson nodes, with singular or multiple presentation snippets, can then be displayed on the web-enabled display or the mobile device responsive to the bowling swing analysis.
[0103] Attachment to an Ancillary Device
[0104] Thus far, the description of the invention has been limited to use of the mobile device 160 to simulate a sports motion by the user holding the mobile device 160 in his or her hand and moving the mobile device 160 in a certain manner (e.g., swinging the mobile device 160 as if it were a golf club). However, advanced players may find it desirable to feel the grip of the sports equipment in sports such as golf, baseball, tennis or fly fishing, for example. In the case of golf, for a right handed player, advanced players may have a grip on the club so that the left hand is rotated approximately 20 degrees from center towards the body. Such a grip on the golf club handle enables the club head to be more closed through impact which in turn makes it easier to draw the golf ball, that is, create a ball flight that bends to the left.
[0105] The methods of the present invention relating to analysis of sports motions are generalizable to also include attachment of the mobile device to sports equipment, or to weighted grips simulating the sports equipment.
[0106] As an example, FIG. 13 shows a mobile device holder 161 to securely mount the mobile device 160 to an ancillary device 163 via an interlocking clip 162 , which in the illustrated embodiment is a physical golf club but could instead (for golf) be a weighted golf grip. In an embodiment, the ancillary device 163 is comprised of a 24″ long steel or graphite golf club shaft with a golf grip at one end and a 6 ounce weight at the other. Preferably, the entire ancillary device 163 weighs approximately 11 ounces (similar to a golf club driver), and the center of mass is approximately 6-8″ inches from the weight, so as to simulate an actual golf club, which typically has the center of mass approximately ¼-⅓ the length of the shaft closer to the club head. FIG. 12 is presented for illustrative purposes, and is not meant to be limiting. Other sports, such as baseball, tennis, and fly fishing, would have different ancillary devices but the grip, weighting and center of mass more accurately simulate the actual sports equipment, and/or the mobile device could be attached to the actual sports equipment via the holder 161 .
[0107] While this invention has been described in conjunction with the various exemplary embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention. | A family of sports teaching applications that delivers customized lessons driven by the analysis of user body motions where data is captured via the accelerometer and gyroscope in a mobile device, such as a smartphone is provided. Each specific application is designed with motion data models that define proper form for athletes in club sports such as, but not limited to, golf, baseball hitting, hockey, polo, and racquet sports such as, but not limited to, table tennis, squash, badminton and throwing sports like baseball pitching, football, discus, javelin, and shot put, and other sports such as skiing and running. The Invention is also applicable to the customized fitting of sports equipment such as golf clubs, baseball bats, tennis racquets, etc. to athletes unique swing motions and swing speeds, and for multiplayer tournament competitions via the Internet utilizing the swing motion analysis and system described herein. | 6 |
This is a continuation in part of U.S. Ser. No. 07/937,129, filed Aug. 31, 1992, now U.S. Pat. No. 5,259,276, issued on Nov. 9, 1993.
BACKGROUND OF THE DISCLOSURE
The present disclosure is directed to a ratchet wrench mechanism, and one which is different in operation in that it does not include a ratchet mechanism which advances by a finite measure. This structure incorporates a toothless drive which thereby enables rotation by an infinitely varied amount.
In the use of hand tools, there is a well appreciated need for ratchet type mechanisms. Indeed, ratchets in conjunction with socket drives are used by practically all machinist and repair personnel. As a generalization such devices are extremely handy for service work. There is however a limitation at times arising from the physical locale at which the socket connection is somewhat constrained. Sometimes, rather than use a socket connected with a ratchet, the only choice which is permitted by the circumstances of use is to engage a nut or bolt with an open end wrench. Nonadjustable box and open end wrenches are normally available for this purpose. Especially with an open end wrench, a nut can be engaged from the side without having to slip the wrench over the head. This type of motion permits one to engage the bolt head or nut on the bolt laterally. Sometimes, that is the only access which is permitted.
One of the difficulties with use of a ratchet wrench is the fixed incremental movement. The fixed increment of travel is determined by the spacing of the teeth involved in the ratchet mechanism. These teeth are normally arranged in a regular spacing. Since the device moves a catch mechanism from the first tooth to the next tooth, each advance of the ratchet requires a finite advance. In other words, the ratchet mechanism must drive the socket through a fixed angle of rotation, or some multiple thereof. If it is convenient, the handle can be moved so far that several incremental steps are achieved during the ratchet advance. If it is not handy or if the external working space is constrained, then difficulties arise in this regard. As will be understood, if the arcuate motion of the user is constrained by half, then tightening requires twice as many ratcheting movements to achieve the same amount of wrench transferred rotation.
The foregoing is especially true in a system which utilizes a wrench which has a fixed step or lead in the ratchet mechanism. Briefly, that describes those devices which are in popular fashion nowadays. Such a device is exemplified by the disclosure in U.S. Pat. No. 3,204,496. Briefly, this patent is directed to a ratchet mechanism which uses a spring loaded FIG. 8 shaped tooth caught in a raceway on the exterior of a socket and on the interior of a housing. In U.S. Pat. No. 3,398,612 a ratchet mechanism is shown which has spheres captured in a raceway, the raceway having one wall which is a cylinder and another wall which has an undulating surface which creates a wedge shaped cavity. It is a sphere related ratchet mechanism.
Another structure is shown in U.S. Pat. No. 4,491,043 illustrating a number of different embodiments which utilize a sphere which moves into a locking or unlocking position in conjunction with a tapered cavity. Last of all U.S. Pat. No. 3,590,667 sets forth a roller as opposed to a sphere, and the roller is captured in a tapered chamber.
The device of the present disclosure can be readily distinguished from the structures described above in the four specific references noted. The present apparatus utilizes a socket of conventional six sided construction but one which omits one side so that it functions as an open end wrench or socket. The structure further utilizes a surrounding, external, centered rib, halfway between the top and bottom, which rib provides a working surface on the top and bottom. The rib is incorporated to support, in frictional sliding engagement, two opposing wedges. One wedge is located above the rib and another is located below the rib. The wedges are enclosed in internal cavities each of which has a tapered surface positioned to drive the wedge frictionally into contact with the surrounding rib around the socket. This movement by the two opposing wedges provides a clamping action, thereby preventing further movement. On clamping, the wedges prevent further rib and socket rotation and assist in locking the socket against rotation. The wedges are long enough to span the gap in the rib at the open side of the socket. In summary, the locking action occurs when the ratchet mechanism is rotated in the direction resulting in wedge latching, and that can occur after any amount of angular rotation in the opposite direction. That might occur anytime when the user operates the device in the opposite direction to achieve latching. The incremental movement is not a fixed angle of rotation as occurs with a tooth equipped ratchet mechanism.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a plan view of a ratchet mechanism in accordance with the present disclosure which incorporates a socket having an open side;
FIG. 2 is a sectional view along the line 2--2 of FIG. 1 showing details of construction of the head of the wrench which supports a socket;
FIG. 3 is a view of the head of the socket wrench with a portion of the top plate broken away to illustrate details of construction of a guide plate;
FIG. 4 is a view similar to FIG. 3 with a portion of the top plate broken away to show the guide plate in conjunction with a long wedge and a wedge receiving chamber; and
FIG. 5 is a side view of the wedge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is now directed to FIG. 1 of the drawings where the numeral 10 identifies a ratchet wrench in accordance with the present disclosure and one similar to the patented wrench. While many details will be set forth, one of the features of this ratchet wrench is the fact that it includes a head which provides a ratchet type motion. Nevertheless, in the forward direction, the motion is not incremental. The stroke in the forward direction can be as short or as long as required. For this purpose, the disclosure will focus on FIGS. 1 and 2 considered jointly for the moment, and then details of construction will be given thereafter. Briefly, the apparatus includes upper and lower handle plates 12 and 14 which are joined together by suitable fasteners 16 and 18. These have the form of fastening bolts with tapered heads, and the handle plates 12 and 14 are provided with counter sunk openings to thereby permit fastening. Moreover, the two handle portions terminate in a circular housing which is constructed so that it encircles approximately 300° of a socket 20 which is captured in the housing. The socket 20 has sufficient height as shown in FIG. 2 so that the internal flats 22 are able to grasp the head of a bolt or a mating nut for the bolt. In particular, six flats are normally required on a bolt head in accordance with industry standards, and the socket has socket flats deployed to mate with the six flats on the bolt head. The socket however is open at one side, there being a gap 24 in the socket where one of the six flats has been omitted. This defines a gap 24 in the socket which is sufficient in width to enable the socket to slide over a bolt, and then move upwardly or downwardly as required to come into engagement with the flats on the bolt head. As will be further understood, the six flats on the interior of the socket 20 are equal to each other in width and height. The flats are enabled for grasping of the bolt head or nut. Even so, the omission of one socket flat permits the socket to slide engage the bolt stem from the side, thereby enhancing the facility in which the device is used. The socket is permanently captured in the wrench head by the encircling arms 26 and 28. The arms 26 and 28, if extended, would then define a full circle construction supporting the socket. The gap that is constructed in the socket is repeated in the wrench head so that the encircling arms 26 and 28 form an opposing support housing for structural integrity while opening at the gap to enable the bolt shaft to slide into the head and socket.
The socket is constructed with a surrounding peripheral shoulder 30. The encircling shoulder 30 is defined by a pair of parallel, outwardly facing surfaces 32 and 34. The surfaces 32 and 34 serve as locking surfaces to lock the socket. Before locking does occur, the surrounding shoulder with the surfaces 32 and 34 serves as a guide mechanism which assures that the socket remains engaged with the handle during rotation. As will be observed in FIG. 2 of the drawings, the two halves which define the handle are undercut to thereby define a circular undercut cavity sized to receive the protruding shoulder 30 so that rotation is permitted. Further, rotation is assured with minimum friction because the protruding shoulder 30 has modest clearance on all faces so that the socket 20 can rotate substantially without drag. While the socket may fit snugly against the handle, modest clearance is provided so that rotation can be readily obtained.
The cavity just mentioned fits around the protruding shoulder 30. It is also enhanced by defining certain wedge receiving cavities which will be detailed later. Before going to that aspect of the structure, FIG. 3 will be observed to incorporate a portion of the handle broken away. This shows details of construction of the fastener 18 which is positioned in the two portions defining the handle to hold them together. An upstanding spacer 36 is located in the cavity and has a central opening to receive the fastener 18. When in position, the spacer 36 locks a pair of guide plates in spaced position. One guide plate is at one end of the spacer 36 and is identified by the numeral 38. Another guide plate 40 is parallel and is placed above the spacer 36. The spacer 36 in conjunction with the spaced plates 38 and 40 are held in position by the fastener 18 which passes through these components. The height of the spacer 36 is determined primarily by the thickness of the shoulder 30. This is better shown in FIG. 2 of the drawings. There, the spacer 36 is taller than and located immediately adjacent to the shoulder 30.
Consider the wedge construction in detail. In FIG. 5 of the drawings, one of the wedges 50 is illustrated and the mode of operation of that particular wedge will be extended to the opposing wedge. First, the handle portion 12 has an internal cavity with a sloping face 48 (see FIG. 4). The sloping face 48 is sized so that it has a deep end and a shallow end. The wedge 50 is placed in the cavity. A coil spring 52 urges the wedge 50 toward the opposite or deep end of the cavity. The shallow end of the cavity is represented by the symbol S while the deeper end is marked at D. There are limitations on movement of the wedge as a result of the tapering cavity. The wedge has an exposed face which bears against the opposing face of the shoulder 30. When the wedge is against the coil spring to compress it, there is more friction between the wedge and shoulder, thereby limiting wrench ratcheting action.
When the wedge is at the shallow end of the cavity which is provided for it, the wedge is jammed against the shoulder 30 and pinches the shoulder, thereby preventing rotation. The action of one wedge cannot be considered in isolation; rather, the wedge shown in FIG. 5 installed above the shoulder 30 is duplicated by a similar wedge 50 below the shoulder. The two wedges together form a pinching movement, thereby clamping the shoulder 30 and preventing rotation. This pinching movement is sufficient to stop rotation.
Returning momentarily to FIG. 2 of the drawings, it will be observed that the shoulder 30 is clamped or pinched at two locations by two edges. The shoulder 30 thus is always clamped by the two pair of wedges. While the gap 24 might be at the wedges, the wedges are sufficiently long to span the gap. The provision of two long wedges at location sufficiently spaced to assure proper clamping, enables the system to rotate continuously in one direction and yet prevents socket rotation in the opposite direction without regard to the location of the gap. During rotation, the shoulder 30 is always facing the two facing wedges.
In FIG. 4, the shoulder 30 is clamped as mentioned to prevent rotation in one direction. This confines operation of the socket to a single direction of rotation. For rotation in the opposite direction, the socket is merely flipped over by the user to get a device which rotates in the opposite direction. Rotation in a particular circumstance for a user thus requires that the mechanism be positioned so that the ratchet mechanism provides the benefit desired by the user. If it is not oriented to help the user, the user merely has to retract the socket from engagement, flip the entire tool 10 over, and then rotate in the opposite direction. In other words, the structure of the socket is limited in the direction of rotation. It can rotate only in one direction, and locks on an attempt to rotate in the opposite direction. Nevertheless, bi-directional operation is obtained from the device by virtue of the fact that it is symmetrically constructed, referring to the top and bottom faces of the system. This symmetrical construction enables one to obtain a bilateral device capable of rotation relative to a bolt head or nut. While the device internally permits rotation in only one direction, the device in application works in both directions.
Consider how this tool 10 is implemented by the user. The socket is simply engaged with a nut or bolt head. It is rotated in one direction to either tighten or loosen the nut as required. This rotation involves movement of the socket so that the wedges 50 shown in FIG. 5 are urged against the compressed springs 52, thereby grasping the shoulder 30. When the wedges are pushed to the end of the cavity, rotation of the socket is permitted. When however the socket is rotated in the opposite direction, the shoulder 30 moves in a direction causing the wedges 50 to slide towards the shallow end of the cavity provided for the wedges, and clamping occurs. Clamping even occurs over the gap 24 and further rotation is forbidden by the wedges. When the clamping action occurs, clamping is made complete without requiring rotation through an incremental advance of one tooth as occurs with a ratchet system utilizing a tooth locking mechanism. This locking occurs because there is a frictional wedging action by the wedge 50 in conjunction with the shoulder 30.
While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow: | A ratchet wrench mechanism is set forth. It is constructed so that it advances on rotation in one direction and locks when attempting to rotate the ratchet in the opposite direction. It does not require incremental advances as occur with a toothed locking mechanism in the ratchet. Rather, the handle supports a socket which has a surrounding shoulder with upper and lower faces. The socket and shoulder have a gap to permit socket insertion over a bolt. The shoulder passes through wedge shaped chambers or cavities in the housing, and wedges loaded by a bias spring are forced towards the narrow end of the tapered chambers. Rotation in one direction is permitted because the wedges are retracted to the large end of the cavity, but rotation in the opposite direction is forbidden when the wedges move to the opposite and narrow end of the cavity. | 1 |
TECHNICAL FIELD
The present invention relates generally to drilling equipment and more particularly to a reverse percussion device for a hydraulic percussive drill which allows the benefits of reverse percussion operation during difficult drilling conditions but eliminates the adverse effect on component life normally associated with such operation.
BACKGROUND OF THE INVENTION
A typical blasthole drilling system includes a drill carrier or "trackdrill", an impacting device or "drifter", a drill string comprising a drill steel and couplings, and a bit. The blasthole drilling operation forms holes in a rock formation which are subsequently filled with an explosive material and detonated to fracture the rock into small pieces which can subsequently be removed.
The holes are usually drilled in a specific grid pattern. Certain circumstances, however, may cause the bit to become lodged or stuck in the hole. For instance, shifting of loose material in the hole, failure to adequately flush drilled material out of the hole, or debris falling into the hole often result in the bit becoming stuck in the hole. In these cases, the bit cannot be easily extracted. Consequently, time is lost in attempting to remove the lodged bit from the hole. In some cases, the bit and steel become lodged to the extent that removal is impractical or impossible. In these cases, the bit and steel are often left in the hole and a new hole drilled adjacent to the original hole, thereby resulting in the loss of both time and equipment.
Reverse percussion devices, which create a percussive force in a direction opposite to the percussive force generated during normal drilling, are known in the prior art. When a reverse percussion device is added to a drifter, recovery of a lodged bit and steel is facilitated by superimposing an upward repetitive impacting force on the steady upward force exerted by the feed system.
In particular, conventional reverse percussion devices operate on the principle that the reverse percussion piston, when idle, rests in a downward position. The piston is held in position by seal friction against the influence of any residual pressure or system back pressure in the reverse percussion chamber. When the operator perceives a need for reverse percussion activation, a manual control valve connects supply pressure to the reverse percussion chamber. The reverse percussion piston forces a shank adapter into the normal drilling impact position, holding the shank adapter in position with supply pressure. The drifter piston then strikes the shank adapter normally, causing the reverse percussion piston to move downward slightly in response to the impact and then return quickly to its upward position. A slight impact is created against the shank adapter collar by this action and the impact assists in retracting the stuck drill string.
When the need for the reverse percussion no longer exists, the manual control valve vents the reverse percussion chamber to a tank and the reverse percussion piston is allowed to return to its downward position, pushed by the shank adapter collar while retracting the drill string from the hole.
More particularly, known devices function by hydraulically forcing a shank adapter upward into its normal drilling position, during retraction of the bit from the hole, and causing the drifter piston to cycle normally. The shank adapter is repeatedly struck and forced downward by the drifter piston and then abruptly returned into position by the constant hydraulic force against the reverse percussion piston. This motion tends to loosen the stuck bit. However, wear on the drill string components is accelerated because the drill string connecting threads are alternately tightened and loosened with each impact cycle. In addition, these devices are subject to abuse when left operating even when the bit is not being struck. Under this condition, all energy generated by the reverse percussion operation must be dissipated in the drill string, which further aggravates the wear problem on component parts.
Such prior art reverse percussion devices, however, are somewhat destructive to drilling equipment. This is due in part to the fact that the full drifter piston energy is delivered to the drill string, but very little of the energy is actually used. Another disadvantage associated with the prior art is that such devices are subject to operator abuse since manual control allows the reverse percussion device to be activated when it is not actually necessary, thereby accelerating damage to equipment and system components.
Additionally, conventional reverse percussion devices are often sensitive to system backpressure. This is attributable to the dependence upon seal friction alone to prevent activation of the reverse percussion device under the influence of backpressure. Because the accumulator must operate over a very large pressure range from system backpressure to large pressure spikes generated by the drifter piston impact, accumulator life tends to be short. Yet another disadvantage associated with the prior art is the requirement for additional control valve components in the hydraulic system.
It would therefore be desirable to provide a reverse percussion device which overcomes the problems associated with the prior art. In particular, it would be desirable to provide a reverse percussion device having a cycling piston which eliminates wear and tear of equipment, which eliminates operator abuse and enhances the efficiency obtained from reverse percussion devices of the prior art.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a reverse percussion device which functions automatically such that manual or operator initiation is unnecessary.
It is another object of the present invention to provide a reverse percussion device which includes a cycling piston to eliminate the necessity for alternate loosening and tightening of drill string threads.
Still another object of the present invention is to provide a reverse percussion device which reduces the wear and tear on equipment due to repetitive impact.
Yet another object of the present invention is to provide a reverse percussion device which enhances the efficiency of withdrawing a lodged bit from a drilled hole.
A still further object of the present invention is to provide a reverse percussion device which reduces the loss of drilling equipment due to lodged drill bits which must be left in drilled holes.
These and other objects of the invention are provided in a reverse percussion device which utilizes its own cycling piston, thereby eliminating the drifter piston from the reverse percussion operation and eliminating the alternate loosening and tightening of drill string threads. Preferably, the reverse percussion device includes an automatic disabling feature which causes the reverse percussion operation to cease when the drill bit is free to retract normally.
In one embodiment, the reverse percussive device includes a housing having first and second chambers extending along a longitudinal axis of a hydraulic percussive drill. The first chamber has a pair of opposed facing edges. An anvil is also disposed within the first chamber of the housing and positioned to move between first and second control positions along the longitudinal axis between the pair of opposed facing edges. A piston having a bore therethrough for receiving an elongated shank adapter is disposed in the second chamber of the housing and positioned to move along the longitudinal axis. A valve is positioned to move between first and second control positions along the longitudinal axis and is adapted to control the movement of the piston within the housing. Fluid pressure is controlled and cooperates with the valve (a) for maintaining the piston in a stalled position during a first mode of operation in which the anvil is in the first control position within the first chamber, (b) for cyclically-reciprocating the piston within the second chamber during a second mode of operation corresponding to movement of the anvil from the first control position to the second control position within the first chamber, and (c) for returning The piston back to its stalled position following the second mode of operation corresponding to movement of the anvil from the second control position back to the first control position.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention as will be described. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the following Detailed Description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference should be made to the following Detailed Description taken in connection with the accompanying drawings in which:
FIG. 1 is illustrates a blasthole drilling system in which a drill bit has become lodged in a drilled hole;
FIG. 2 is a cross-sectional view of a drifter, shank adapter and reverse percussion device in accordance with the present invention;
FIG. 3 is an exploded cross-sectional view of the reverse percussion device illustrated in FIG. 2 in which the device is at rest;
FIG. 4 is an exploded cross-sectional view of the reverse percussion device shown in FIG. 2 in which the device is activated; and
FIG. 5 is an exploded cross-sectional view of the reverse percussion device shown in FIG. 2 in which the device has been activated and the piston is forced in a direction opposite the shoulder of the shank adapter.
Similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION
Referring now to FIG. 1, a blasthole drilling system is shown. The system includes trackdrill or drill carrier 10, drifter or impacting device 12, drill string 14 and bit 18. During drilling operations, bit 18 often becomes lodged in the drilled hole due to debris 16 or the like. It therefore becomes necessary to loosen or dislodge bit 18 such that it may be pulled through debris 16 and removed from the drilled hole.
The reverse percussion device 30 in accordance with the present invention is shown in FIGS. 2-5, with device 30 incorporated into impacting device 12. FIG. 2 thus illustrates the novel reverse percussion device in relation to other system components in accordance with the present invention. As shown in FIG. 2, drifter 12 includes an elongated shank adapter 22 extending longitudinally therethrough. A drifter piston 20 strikes the shank adapter 22 at one end; an opposite end of the adapter attaches to the drill string. The reverse percussion device 30 includes a housing 32 in which piston 34, valve 36 and reverse percussion anvil 38 are positioned. Housing 32 includes first and second chambers, 76 and 78, respectively, extending along the longitudinal axis. First chamber 76 has a pair of opposed facing edges 58 and 56.
In a preferred embodiment, reverse percussive device 30 includes housing 32 having first chamber 76 and second chamber 78 extend along a longitudinal axis of a hydraulic percussive drill. As mentioned above, first chamber 76 has a pair of opposed facing edges 58 and 56. Anvil 38 is also disposed within first chamber 76 of housing 32 and positioned to move between first and second control positions along the longitudinal axis between edges 58 and 56. Piston 34, which is disposed in second chamber 78 of housing 32 and positioned to move along the longitudinal axis, has a bore therethrough for receiving elongated shank adapter 22. Valve 36 is positioned to move between first and second control positions and is adapted to control the movement of piston 34 within housing 32.
Reference is now had to FIGS. 3-5. FIG. 3 illustrates the reverse percussion device 30 of FIG. 2 in accordance with the invention during a first mode of operation in which piston 34 of the device 30 is at rest or "stalled". As discussed in more detail herein, FIGS. 4-5 show the positioning of the various components of the device 30 when the anvil 38 has moved to its second position, thereby initiating a second mode of operation wherein the piston 34 cyclically-reciprocates between first and second positions.
A more detailed description of the operation of the reverse percussion device in accordance with the present invention will now be described with reference to FIGS. 3-5, collectively. Passages 64 and 66 are at a constant high pressure (PS), connected to a source of high pressure fluid through an internal high pressure fluid reservoir 72 or alternatively, a high pressure accumulator. Passages 60 and 62 are at a constant low pressure (PE), connected to an external fluid reservoir or tank. While not meant to be limiting, passages 64 and 66 operate at pressure in the range of approximately 2000-3000 psi and preferably at about 2500 psi while passages 60 and 62 operate at pressures in the range of about 50-200 psi and preferably at about 150 psi. Pressure in passage 68 (PD) and pressure in passage 70 (PV) vary between PS and PE during the cyclic operation. The motion of piston 34 is controlled by pressures PD and PS against areas A1 and A2, respectively. The motion of valve 36 is controlled by pressures PV and PS against areas A3 and A4, respectively. It should be appreciated that the area of A1 is greater than A2 and the area of A3 is greater than A4.
Pressure PV in passage 70 is controlled by the position of piston 34, which determines whether the annular area established by edges 44 and 46 is connected to the annular area established by edges 40 and 42 or the annular area established by edges 48 and 50. Pressure PD in passage 68 is controlled by the position of valve 36, which determines whether passage 68 is connected to a flow passage created by edge 52 or a flow passage created by edge 54.
When the reverse percussion device is at rest as shown in FIG. 3, pressures PD in passage 68 and PV in passage 70 are both connected to PS. Additionally, piston 34 and valve 36 are stalled. The differential pressures acting on areas A1 and A2 with area A1 being greater than that of A2 hold piston 34 firmly to the right, thereby forcing anvil 38 against face 58 in first chamber 76 of housing 32. Motion does not occur under the influence of any fluid forces until anvil 38 is mechanically forced away from face 58 and against opposed face 56 in first chamber 76, as shown in FIG. 4. When bit 18 is being retracted from the hole, anvil 38 acts as a retainer for shank adapter 22, transferring the retracting force through anvil 38 and piston 34 into the hydraulic fluid.
The geometry of areas A1 and A2 is such that the net fluid force holding the anvil against face 58 will be greater than the normal retracting forces. If the retracting force exceeds the net fluid force holding anvil 38 against face 58, such as when the bit becomes stuck or jammed, anvil 38 is forced against face 56 and the reverse percussion device 30 begins operation automatically. As further illustrated in FIG. 4, edge B on piston 34, which is positioned and moves within second chamber 78 of housing 32, closes off edge 42, and edge C on piston 34 has uncovered edge 48. This action in turn causes pressure PV in passage 70 to be connected to pressure PE rather than PS, thereby forcing valve 36 to the right and thus connecting pressure PD in passage 68 to PE instead of PS. Once these pressure switches have occurred, reverse percussion device 30 begins a normal cyclic operation. The net fluid force on piston 34 is toward the left, and piston 34 accordingly begins to move in that direction within second chamber 78 as shown in FIGS. 4 and 5. As the piston moves to the left, fluid is pushed by area A1 through passage 68 and the valve 36 into passage 62, which is connected to an external low pressure fluid reservoir. The fluid preferably passes through a control orifice 74 contained in passage 62, which regulates the speed of the piston retracting stroke. The area A5 of the orifice 74 has a relationship to A1, and is approximately 1-5% of A1.
As the piston continues to move to the left on its retract stroke as illustrated in FIG. 5, pushing fluid out through control orifice 74, edge B closes off edge 46 and edge A then uncovers edge 44. This connects pressure PV in passage 70 to PS and valve 36 moves to the left again. When edge D has closed off edge 54 and edge E has uncovered edge 52, pressure PD in passage 68 will be connected to PS and the drive stroke will be initiated. Piston 34 and valve 36 positions at this time are shown in FIG. 5.
As piston 34 moves to the right on its own stroke, edge A closes off edge 44 and edge B then uncovers edge 46, connecting pressure PV once again to PE and causing valve 36 to move again to the right as shown in FIG. 4. The timing of this motion is such that edge D uncovers edge 54 just after piston 34 impacts anvil 38, and piston 34 begins a new cycle. The energy of the impact against anvil 38 is transmitted into the shoulder of shank adapter 22, through the drill steel and bit 18, and into the rock fragments or other debris 16 which are causing bit 18 to be jammed. This energy causes debris 16 to be broken up and dispersed, thereby allowing bit 18 to be freely retracted from the drilled hole.
As long as bit 18 is encountering sufficient resistance to hold anvil 38 against face 56, piston 34 will continue its repetitive striking of anvil 38. However, when bit 18 is freed and anvil 38 is driven back against face 58 by the upward force of piston 34, edge C again closes off edge 48 and edge B uncovers edge 42. This causes valve 36 to move back to the left as illustrated in FIG. 3, maintaining pressure PD in passage 68 connected to PS and holding piston 34 in the rest position, as shown in FIG. 3.
In contrast to the prior art, the piston 34 of the reverse percussion device 30 is held upward against anvil 38 by supply pressure in the stalled condition as illustrated in FIG. 3. When the downward force exerted by a shank adapter against anvil 38 exceeds the upward force on piston 34 (indicating a stuck drill string 14), piston 34 moves into its normal impacting position and begins to impact on anvil 38. The impact energy is transmitted through anvil 38 into the shank adapter face. It should be appreciated that drifter piston 20 has no function in the reverse percussion operation and whether the drifter piston 20 cycles or not is thus immaterial.
When the lodged bit is freed, the downward force exerted on anvil 38 by the shank adapter collar fails, and anvil 38 is pushed into its upward or idle position by piston 34. Piston 34 stalls in this position. While not required, an alternative embodiment of the invention includes a pilot-operated check valve in the exhaust line to limit internal leakage while in the stalled condition.
The reverse percussion device of the present invention thus provides automatic operation, thereby eliminating operator abuse. The reverse percussion device is completely self-contained with the exception of hose connections. No external control valves are required with the device of the present invention. Additionally, the reverse percussion devices do not "rattle" the drill string in operation, so that accessory life is improved. Moreover, these devices use low energy consumption and delivery. Another advantage of the present invention is that accumulators do not fail or require maintenance.
It should be appreciated by those skilled in the art that the specific embodiments disclosed above may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. | A reverse percussion device for use with hydraulic percussive drills is provided. The reverse percussion device includes a cycling piston, valve and anvil. The piston and valve move in opposing directions between low and high pressure passages automatically until a lodged drill bit is freed, thereby facilitating removal of the drill bit from the drilled hole and eliminating alternate loosening and tightening of drill string threads. The reverse percussion device preferably includes an automatic disabling feature which causes the reverse percussion operation to cease when the bit is free to retract normally. | 4 |
This is a continuation-in-part of U.S. application Ser. No. 08/221,911, filed Apr. 1, 1994, now U.S. Pat. No. 5,421,329.
BACKGROUND OF THE INVENTION
Pulse oximetry is used to continuously monitor the arterial blood oxygen saturation of adults, pediatrics and neonates in the operating room, recovery room, intensive care units, and increasingly on the general floor. A need exists for pulse oximetry in the delivery room for monitoring the oxygen status of a fetus during labor and delivery, and for monitoring the oxygen status of cardiac patients.
Pulse oximetry has traditionally been used on patient populations where arterial blood oxygen saturation is typically greater than 90%, i.e., more than 90% of the functional hemoglobin in the arterial blood is oxyhemoglobin and less than 10% is reduced hemoglobin. Oxygen saturation in this patient population rarely drops below 70%. When it does drop to such a low value, an unhealthy clinical condition is indicated, and intervention is generally called for. In this situation, a high degree of accuracy in the estimate of saturation is not clinically relevant, as much as is the trend over time.
Conventional two wavelength pulse oximeters emit light from two Light Emitting Diodes (LEDs) into a pulsatile tissue bed and collect the transmitted light with a photodiode positioned on an opposite surface (transmission pulse oximetry), or an adjacent surface (reflectance pulse oximetry). The LEDs and photodetector are housed in a reusable or disposable sensor which connects to the pulse oximeter electronics and display unit. The "pulse" in pulse oximetry comes from the time varying amount of arterial blood in the tissue during the cardiac cycle, and the processed signals from the photodetector create the familiar plethysmographic waveform due to the cycling light attenuation. For estimating oxygen saturation, at least one of the two LEDs' primary wavelength must be chosen at some point in the electromagnetic spectrum where the absorption of oxyhemoglobin (HbO 2 ) differs from the absorption of reduced hemoglobin (Hb). The second of the two LEDs' wavelength must be at a different point in the spectrum where, additionally, the absorption differences between Hb and HbO 2 are different from those at the first wavelength. Commercial pulse oximeters utilize one wavelength in the near red part of the visible spectrum near 660 nanometers (nm), and one in the near infrared part of the spectrum in the range of 880 nm-940 nm (See FIG. 1). As used herein, "red" wavelengths or "red" spectrum will refer to the 600-800 nm portion of the electromagnetic spectrum; "near red", the 600-700 nm portion; "far red", the 700-800 nm portion; and "infrared" or "near infrared", the 800-1000 nm portion.
Photocurrents generated within the photodetector are detected and processed for measuring the modulation ratio of the red to infrared signals. This modulation ratio has been observed to correlate well to arterial oxygen saturation as shown in FIG. 2. Pulse oximeters and pulse oximetry sensors are empirically calibrated by measuring the modulation ratio over a range of in vivo measured arterial oxygen saturations (SaO 2 ) on a set of patients, healthy volunteers or animals. The observed correlation is used in an inverse manner to estimate saturation (SpO 2 ) based on the real-time measured value of modulation ratios. (As used herein, SaO 2 refers to the in vivo measured functional saturation, while SpO 2 is the estimated functional saturation using pulse oximetry.)
The choice of emitter wavelengths used in conventional pulse oximeters is based on several factors including, but not limited to, optimum signal transmission through blood perfused tissues, sensitivity to changes in arterial blood oxygen saturation, and the intensity and availability of commercial LEDs at the desired wavelengths. Traditionally, one of the two wavelengths is chosen from a region of the absorption spectra (FIG. 1) where the extinction coefficient of HbO 2 is markedly different from Hb. The region near 660 nm is where the ratio of light absorption due to reduced hemoglobin to that of oxygenated hemoglobin is greatest. High intensity LEDs in the 660 nm region are also readily available. The IR wavelength is typically chosen near 805 nm (the isosbestic point) for numerical convenience, or in the 880-940 nm spectrum where additional sensitivity can be obtained because of the inverse absorption relationship of Hb and HbO 2 . Unfortunately, pulse oximeters which use LED wavelengths paired from the 660 nm band and 900 nm bands all show diminished accuracy at low oxygen saturations.
SUMMARY OF THE INVENTION
According to the invention, more accurate estimates of low arterial oxygen saturation using pulse oximetry are achieved by optimizing a wavelength spectrum of first and second light sources so that the saturation estimates at low saturation values are improved while the saturation estimates at high saturation values are minimally adversely affected as compared to using conventional first and second wavelength spectrums. It has been discovered that calculations at low saturation can be significantly improved if the anticipated or predicted rates of absorption and scattering of the first wavelength spectrum is brought closer to, optimally equal to, the anticipated or predicted rates of absorption and scattering of the second wavelength spectrum than otherwise exists when conventional wavelength spectrum pairs are chosen, such as when conventionally using a first wavelength centered near 660 nm and a second wavelength centered anywhere in the range of 880 nm-940 nm.
The present invention solves a long felt need for a pulse oximeter sensor and system which provides more accurate estimates of arterial oxygen saturation at low oxygen saturations, i.e. saturations equal to or less than 80%, 75%, 70%, 65%, or 60%, than has heretofore existed in the prior art. The sensor and system is particularly useful for estimating arterial saturation of a living fetus during labor where the saturation range of principal importance and interest is generally between 15% and 65%, and is particularly useful for estimating arterial saturation of living cardiac patients who experience significant shunting of venous blood into their arteries in their hearts and hence whose saturation range of principle importance and interest is roughly between 50% and 80%. By contrast, a typical healthy human has a saturation greater than 90%. The invention has utility whenever the saturation range of interest of a living subject, either human or animal, is low.
In addition to providing better estimates of arterial oxygen saturation at low saturations, the sensor, monitor, and system of the invention further provide better and more accurate oxygen saturation estimates when perturbation induced artifacts exist and are associated with the subject being monitored.
When the rates of absorption and scattering by the tissue being probed by the first and second wavelength spectrums are brought closer together for the saturation values of particular interest, improved correspondence and matching of the tissue actually being probed by the first and second wavelengths is achieved, thus drastically reducing errors introduced due to perturbation induced artifacts. For example, when light of one wavelength is absorbed at a rate significantly higher than that of the other wavelength, the light of the other wavelength penetrates significantly further into the tissue. When the tissue being probed is particularly in-homogenous, this difference in penetrations can have a significant adverse impact on the accuracy of the arterial oxygen saturation estimate.
Perturbation induced artifacts include, but are not limited to, any artifact that has a measurable impact on the relative optical properties of the medium being probed. Perturbation induced artifacts include but are not limited to the following:
(1) variations in the tissue composition being probed by the sensor from subject to subject, i.e., variations in the relative amounts of fat, bone, brain, skin, muscle, arteries, veins, etc.;
(2) variations in the hemoglobin concentration in the tissue being probed, for example caused by vasal dilations or vasal constrictions, and any other physical cause which affects blood perfusion in the tissue being probed; and
(3) variations in the amount of force applied between the sensor and the tissue being probed, thus affecting the amount of blood present in the nearby tissue.
In one embodiment, the present invention provides a fetal pulse oximeter sensor with a light source optimized for the fetal oxygen saturation range and for maximizing the immunity to perturbation induced artifact. Preferably, a far red and an infrared light source are used, with the far red light source having a mean wavelength between 700-790 nm. The infrared light source can have a mean wavelength as in prior art devices used on patients with high saturation, i.e., between 800-1000 nm. As used herein, "high saturation" shall mean an arterial oxygen saturation greater than 70%, preferably greater than 75%, alternatively greater than 80%, optionally greater than 90%.
The fetal sensor of the present invention is further optimized by arranging the spacing between the location the emitted light enters the tissue and the location the detected light exits the tissue to minimize the sensitivity to perturbation induced artifact.
According to a preferred embodiment, electrooptic transducers (e.g., LEDs and photodetectors) are located adjacent to the tissue where the light enters and exits the tissue. According to an alternate embodiment, the optoelectric transducers are located remote from the tissue, for example in the oximeter monitor, and optical fibers interconnect the transducers and the tissue with the tissue being illuminated from an end of a fiber, and light scattered by the tissue being collected by an end of a fiber. Multiple fibers or fiber bundles are preferred.
The present invention recognizes that the typical oxygen saturation value for a fetus is in the range of 5-65%, commonly 15-65%, compared to the 90% and above for a typical patient with normal (high) saturation. In addition, a fetal sensor is subject to increased perturbation induced artifact. Another unique factor in fetal oximetry is that the sensor is typically inserted through the vagina and the precise location where it lands is not known in advance.
The present invention recognizes all of these features unique to fetal oximetry or oximetry for low saturation patients and provides a sensor which optimizes the immunity to perturbation induced artifacts. This optimization is done with a trade-off on the sensitivity to changes in saturation value. This trade-off results in a more reliable calculation that is not obvious to those who practice the prior art methods which attempt to maximize the sensitivity to changes in the saturation value. The improvement in performance that results from these optimizations are applicable to both reflectance and transmission pulse oximetry. An example of a fetal transmission pulse oximetry configuration usable with the present invention is described in U.S. patent application Ser. No. 07/752,168, assigned to the assignee of the present invention, the disclosure of which is incorporated herein by reference. An example of a non-fetal transmission pulse oximetry configuration usable with the present invention is described in U.S. Pat. No. 4,830,014, assigned to the assignee of the present invention, the disclosure of which is incorporated herein by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a chart of the absorption characteristics of oxyhemoglobin (HbO 2 ) and reduced hemoglobin (Hb) versus wavelength showing prior art near red and infrared LED wavelengths;
FIG. 2 is a graph of red/IR modulation ratio versus oxygen saturation;
FIG. 3 is a diagram illustrating light penetration through different layers of tissue at different distances;
FIG. 4A is a chart of the variation in extinction and scattering coefficients over a range of wavelengths for different saturation values;
FIG. 4B is a table of the values of FIG. 4A;
FIG. 5 is a diagram illustrating the placing of a sensor on a fetus;
FIG. 6 is a graph illustrating the spectrum of an LED according to the present invention;
FIGS. 7A-B-18A-B are graphs showing experimental modeling of the modulation ratio and saturation error as a function of saturation for different red and infrared wavelength combinations;
FIGS. 19-23 are charts illustrating saturation and the error due to applied force for different combinations of emitter wavelength and emitter-detector spacing from experiments done on sheep;
FIGS. 24 and 25 are diagrams illustrating the construction of a sensor according to the present invention;
FIGS. 26A-B are diagrams of a single package, dual emitter package used in the present invention; and
FIG. 27 is a block diagram of a pulse oximeter according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An understanding of the design of the fetal sensor according to the present invention requires an understanding of the environment in which the sensor will operate. FIG. 3 illustrates the layers of tissue in a typical fetus location where a sensor may be applied. Typically, there would be a first layer of skin 12, perhaps followed by a layer of fat 14, a layer of muscle 16, and a layer of bone 18. This is a simplified view for illustration purposes only. The contours and layers can vary at different locations. For instance, bone would be closer to the surface on the forehead, as opposed to closer muscle on the neck. Such variations in sites can produce the first type of perturbation artifact mentioned in the summary--artifact due to variations in tissue composition.
The general paths of light from an emitter 20 to a photodetector 22 are illustrated by arrows 24 and 26. Arrow 24 shows light which passes almost directly from emitter 20 to detector 22, basically shunted from one to the other, passing through very little blood perfused tissue. Arrow 26, on the other hand, illustrates the deeper penetration of another path of the light. The depth of penetration is affected by the wavelength of the light and the saturation. At low saturation, infrared light penetrates deeper than near red, for instance. The deeper penetration can result in an undesirable variation between the infrared and red signals, since the IR signal will pass through more different layers.
Also illustrated in FIG. 3 is the effect of using an emitter 28 which is spaced on the tissue at a greater distance from a detector 30 than the first pair 20, 22 described. As can be seen, this greater separation results in the penetration of a larger amount of tissue, as indicated by arrows 32 and 34. Thus, the greater spacing increases the depth of penetration, although it will reduce the intensity of the signal received at the detector due to more attenuation from more of the light being absorbed in the tissue and the greater light propagation distances involved.
The second type of perturbation mentioned in the summary is variations in the concentration of blood in the tissue from patient to patient or over time. A lower concentration results in less absorption, increasing the penetration depth. The inventors estimate that the mean penetration depth of photons in a medium is related to the product of the absorption and scattering coefficients, and this estimate is consistent with the findings of Weiss et al., Statistics of Penetration Depth of Photons Re-emitted from Irradiated Tissue, Journal of Modern Optics, 1989, vol. 36, No. 3, 349-359, 354, the disclosure of which is incorporated herein by reference.
Absorption of light in tissue in the visible and near infrared region of the electromagnetic spectrum is dominated by the absorption characteristics of hemoglobin. Absorption coefficients of hemoglobin can be found in the literature, for example Zijlstra, et al., "Absorption spectra of human fetal and adult oxyhemoglobin, de-oxyhemoglobin, carboxyhemoglobin and methemoglobin", Clinical Chemistry, 37/9, 1633-1638, 1991 (incorporated herein by reference). Measured scattering coefficients of tissue are influenced by the methodology of measurement and the model used to fit the data, although there is general agreement in the relative sensitivity to wavelength regardless of method. Tissue scattering coefficients used by the inventors are based on diffusion theory, and are taken from Schmitt, "Simple photon diffusion analysis of the effects of multiple scattering on pulse oximetry", IEEE Transactions on Biomedical Engineering, Vol. 38, No. 12, December 1991, the disclosure of which is incorporated herein by reference.
FIG. 4A is a graph showing the product of the absorption and scattering coefficients for 0%, 40%, 85% and 100% saturations for wavelengths between 600 nm and 1,000 nm. For 85-100% tissue oxygen saturation, good balance or correlation exists between the product of the absorption and scattering coefficients of conventionally chosen wavelength pairs (i.e., 660 nm and 892 nm), as illustrated by points A and B on curve 101.
For low tissue oxygen saturation, points C and D on curve 102 graphically indicate that there is a very significant mismatch between the product of the absorption and scattering coefficients of the 660 nm near red and 892 nm infrared light, with the near red light being more strongly absorbed and scattered. This very significant absorption and scattering mismatch results in very different tissue being probed by the near red and infrared light which significantly degrades the accuracy of the arterial oxygen saturation calculation. In addition, when a large range of low arterial oxygen saturations need to be accurately calculated, as when monitoring a fetus during labor where the range of arterial oxygen saturations can extend between 15% and 65%, it is evident from FIG. 4A that not only does a significant mismatch between the rates of absorption and scattering of the near red and infrared light exist, but that the amount of mismatch will vary significantly as arterial oxygen saturation varies, thus causing a differential inaccuracy of oxygen saturation estimates which varies with the arterial saturation.
On the other hand, points D and E on curve 102 in FIG. 4A illustrate advantages of a preferred embodiment of the invention of choosing first and second wavelengths, i.e., 732 nm and 892 nm, which have absorption and scattering characteristics which are more closely balanced as compared to the prior art pairing of 660 nm and 892 nm for 40% tissue oxygen saturation. As can be appreciated, since the 732 nm extinction and scattering coefficients more nearly match the 892 nm extinction and scattering coefficients, improved overlap of the tissue being probed by the two wavelengths of light result. In addition, 732 nm results in a smaller variation of the extinction and scattering coefficients as a function of oxygen saturation as compared to 660 nm, thus resulting in better and more accurate oxygen saturation estimates over a wider range of saturations. The tissue oxygen saturation values shown in FIG. 4A are closely correlated to arterial oxygen saturation values. In general, a given value of tissue oxygen saturation corresponds to a higher value of arterial oxygen saturation. For example, the inventors estimate that 85% tissue oxygen saturation corresponds to roughly 100% arterial oxygen saturation.
A preferred embodiment of the invention is to optimize the wavelengths used for a sensor to estimate fetal arterial oxygen saturation during labor where the saturation of interest is below 70%, a typical range of interest being between 15% and 65%. Attempting to match or balance the rates of absorption and scattering of the two wavelengths in a fetal sensor is particularly useful since the amount of perturbation induced artifacts are so severe in number and magnitude. For example, for a surface reflection sensor, it is difficult to know a priori where on the fetus the sensor will be located. For example, sometimes it will be on the head, other times the cheek. Hence, the tissue composition varies from application to application. In addition, the force by which the sensor is applied will vary during labor thus introducing still additional perturbation induced artifacts.
Another preferred embodiment of the invention is to use the sensor of the invention for cardiac patients whose range of saturation, where accuracy in calculations is important, is from 50% to 80%.
FIG. 5 illustrates the placement of a sensor 410 on a fetus 412. The sensor is connected by a cable 414 to an external pulse oximeter monitor. As can be seen, sensor 410 is wedged between a uterine wall 416 and the fetus 412. In this instance, the sensor is on the side of the fetus' forehead. This wedging of the sensor applies a force to the skin immediately below the sensor, which reduces the amount of blood in the local tissue. This reduces the amount of blood the light signal will pass through, thus increasing the difficulty of obtaining an accurate blood oxygenation reading.
In choosing an optimum LED wavelength, it must be kept in mind that LEDs have a spectral width, and are not a single narrowband wavelength device like a laser. FIG. 6 illustrates the spectral spread of one preferred wavelength for a sensor according to the present invention, showing the far red wavelength at 735 nm as being the peak wavelength. However, arrow 510 indicates a distribution of wavelengths which can be approximately 25 nm wide at which the intensity level is approximately 50% of that of the peak wavelength. In addition, when manufacturing LEDs, it is difficult to tightly control the mean wavelength. Thus, a purchaser specifying a particular wavelength, such as a 735 nm wavelength in an embodiment of the present invention, will expect to receive LEDs whose actual mean wavelength can vary by 10, 20 or more nanometers from the specified value. A narrow range is typically achieved by testing and sorting.
FIG. 27 is a block diagram of one embodiment of a pulse oximeter implementing the present invention. Light from light source 210 passes into patient tissue 212, and is scattered and detected by photodetector 214. A sensor 200 containing the light source and photodetector may also contain an encoder 216 which provides signals indicative of the wavelength of light source 210 to allow the oximeter to select appropriate calibration coefficients for calculating oxygen saturation. Encoder 216 may, for instance, be a resistor.
Sensor 200 is connected to a pulse oximeter 220. The oximeter includes a microprocessor 222 connected to an internal bus 224. Also connected to the bus is a RAM memory 226 and a display 228. A time processing unit (TPU) 230 provides timing control signals to light drive circuitry 232 which controls when light source 210 is illuminated, and if multiple light sources are used, the multiplexed timing for the different light sources. TPU 230 also controls the gating-in of signals from photodetector 214 through an amplifier 233 and a switching circuit 234. These signals are sampled at the proper time, depending upon which of multiple light sources is illuminated, if multiple light sources are used. The received signal is passed through an amplifier 236, a low pass filter 238, and an analog-to-digital converter 240. The digital data is then stored in a queued serial module (QSM) 242, for later downloading to RAM 26 as QSM 242 fills up. In one embodiment, there may be multiple parallel paths of separate amplifier filter and A/D converters for multiple light wavelengths or spectrums received.
A detector and decoder module 242 determines the wavelength of the light source from encoder 216. One embodiment of circuitry for accomplishing this is shown in commonly assigned U.S. Pat. No. 4,770,179, the disclosure of which is hereby incorporated by reference.
Based on the value of the received signals corresponding to the light received by photodetector 214, microprocessor 222 will calculate the oxygen saturation using well-known algorithms. These algorithms require coefficients, which may be empirically determined, corresponding to, for example, the wavelengths of light used. These are stored in a ROM 246. The particular set of coefficients chosen for any pair of wavelength spectrums is determined by the value indicated by encoder 216 corresponding to a particular light source in a particular sensor 200. In one embodiment, multiple resistor values may be assigned to select different sets of coefficients. In another embodiment, the same resistors are used to select from among the coefficients appropriate for an infrared source paired with either a near red source or far red source. The selection between whether the near red or far red set will be chosen can be selected with a control input from control inputs 254. Control inputs 254 may be, for instance, a switch on the pulse oximeter, a keyboard, or a port providing instructions from a remote host computer.
The inventors of the present invention use both modeling and prototypes to achieve the optimized sensor set forth herein. Several theoretical models exist for describing the scattering of light within tissue. The models used by the inventors assume isotropic scattering within a homogeneous tissue bed. Even though this is a simplification of the true nature of light scattering in tissue (tissue is inhomogeneous and light is scattered primarily in the forward direction), these models are useful for predicting behaviors of pulse oximetry, and the sensitivity to many design parameters.
Utilizing such a model, different choices of LED wavelengths were explored. Tissue characteristics were numerically defined and the basis (calibration) correlation between SaO 2 and modulation ratio was calculated for each wavelength pair considered. Change in physiological condition was simulated by revising one or more of the numerically defined physical parameters. SpO 2 was recalculated from the resulting modulation ratio, and the saturation region where errors were minimized was noted. For arterial saturations above 80% the conventional wavelength choice of 660 nm paired with 890 nm results in optimum performance, while for arterial saturations below 70%, 735 nm band emitters paired with 890 nm gives improved stability.
FIGS. 7 through 18 show the predicted errors due to changing the tissue blood volume to one fourth the basis value for a variety of red and IR LED wavelength pairs. The A FIGS. (such as 7A) show the modulation ratio vs. SaO 2 . The B FIGS. (7B) show the saturation error vs. SaO 2 . This perturbation simulates the effects of blood volume variations within the patient population, anemia, ischemia, or localized exsanguination of blood in the tissue.
Sensitivity of the calibration to a change in tissue blood concentration is shown for several pairings of red and IR wavelengths. In each case, the LED has no secondary emission, and the perturbation is in going from a nominal 2% blood concentration in the tissue to 0.5%.
______________________________________Figure Table IR LEDred LED 805 nm 890 nm 940 nm______________________________________660 nm 7 8 9700 nm 10730 nm 11 12 13760 nm 14 15 16790 nm 17 18______________________________________
FIGS. 7-9 show the type of performance found in conventional pulse oximeters. FIGS. 10-18 show shifting of the optimum performance region from saturations above 80% to lower saturations when the red LED wavelength is chosen in the 700 nm-790 nm region of the spectrum. Light scattering is minimally affected by changes in oxygenation, but light absorption is significantly affected as reduced hemoglobin in the tissue changes to oxyhemoglobin or vice-versa. Pulse oximetry's optimum performance region occurs when there is a balance of the two channels' scattering and absorption properties within blood perfused tissue. Balance occurs when there is a good overlap of the volumes of tissue probed by the two channels, requiring that the penetration depth of light at the two wavelengths be matched. At the higher saturations, this optimum balance occurs with the pairing of wavelengths with a red emitter in the 660 nm band, while at the lower saturations the balance improves with the use of a red emitter in the 730 nm band. The variation of the IR LED from 805 to 940 nm does not produce a significant difference in performance.
When using an LED pair near 730 nm and 890 nm for pulse oximetry, the sensitivity of modulation ratio to changes in oxygen saturation (i.e., the slope of the curve in, for example, FIG. 1) is reduced relative to the use of 660 nm and 890 nm, but the measurement becomes more robust to changes in the tissue characteristics other than oxygen saturation. Noise in the measurement of modulation ratio due to factors such as instrument electronics noise, digitization, or ambient light interference, become more important but can generally be accounted for with good instrument design and appropriate signal processing. The bias and deviations due to tissue optical properties, however, become less significant with the proper choice of emitter wavelengths when they are chosen based on the saturation region of primary interest.
The inventors conducted empirical tests on sheep using prototype sensors. The empirical observations support the use of 735 nm band red LEDs in the design of a pulse oximeter that is more robust to perturbation induced artifacts at the lower saturation region. Reflectance pulse oximetry sensors were fabricated using conventional 660 nm-890 nm LED pairs, and with 735 nm-890 nm pairs.
FIGS. 19-23 show that measurements were taken at a range of oxygen saturation values indicated along the X axis from approximately 100% oxygen saturation to less than 10%. The plots show the calculated saturation (SpO 2 ) for each actual saturation (SaO 2 ) value. The actual saturation value is determined by simultaneously drawing blood samples from an arterial catheter placed in the left femoral artery. SaO 2 is measured on a laboratory co-oximeter (Instrument Labs IL 282 or Radiometer OSM-3). This is the value used on the X axis in these figures.
As can be seen, the diagonal line in FIGS. 19, 20, and 22 indicates the desired result where the calculated value is equal to the actual value as measured with the catheter. The tests illustrated in FIGS. 19, 20, and 22 were done with a nominal force of approximately 50 grams applied to the sensor holding it against the skin.
Using the 660 nm sensor with center-to-center emitter/detector spacing of 14 mm at the tissue, FIG. 19 shows that sensor calibration is very sensitive to the type of tissue probed. The calibration on the head and neck are very different.
Using the 735 nm sensor with a 5.8 mm center-to-center emitter/detector spacing at the tissue, the bias between the head and neck is greatly reduced as illustrated by FIG. 20. There is, however, still substantial sensitivity to surface exsanguination. This is apparent in FIG. 21 which illustrates the effect of a perturbation induced artifact (sensor applied force).
FIG. 22 shows the location insensitivity of a 735 nm sensor with a 14 mm center-to-center emitter/detector spacing. FIG. 23 shows that this sensor is also insensitive to force applied to the sensor (perturbation induced artifact).
It was experimentally confirmed that increasing the emitter/detector center-to-center spacing from 5.8 mm for 735 nm/890 nm LED wavelengths decreased the sensitivity to perturbation induced artifacts, with good performance being achieved by an emitter/detector separation equal to or greater than 10 mm.
Both the modeling and the actual experiments illustrate an improvement in reliability of a saturation measurement achieved by optimizing the red wavelength to be within 700-790 nm range. In addition, reduction of the saturation error reading in the presence of force artifact is achieved by increasing the spacing of the emitters from the detector.
The force applied to the sensor causes exsanguination of the surface tissue, further magnifying the remaining disparities due to the inhomogeneity of the tissue, or causing shunting of light between the emitter and detector, thus causing errors in the saturation calculation. These are compensated for by wider emitter/detector spacing, which results in the light from the red and infrared LEDs penetrating deeper into the tissue, thus increasing the likelihood of their going through, on the average, the same combination of tissue structures, as illustrated in FIG. 3.
FIG. 24 is a top view of a sensor according to one embodiment of the present invention. The sensor face 110 supports a far red LED 112 and an infrared LED 114. These are spaced by a distance of 14 mm center-to-center from a detector 116. Preferably, the centers of the far red and infrared LEDs are no more than 0.5 mm apart. The sensor face is connected by a cable 118 to a connector 120 for connection to the pulse oximeter monitor. FIG. 25 shows a side view of the sensor of FIG. 24, illustrating the fulcrum portion 122 of the sensor and sensor back 132. When placed in utero, the uterus will apply a force to the sensor back 132 and deform the fulcrum 122. As can be seen, this technique results in a force being applied to the sensor resulting in good sensor-fetus contact but possibly resulting in local exsanguination of the tissue. It should be noted that any sensor embodiment will have possible local exsanguination.
The modeling and empirical tests show that the nature of the correlation between modulation ratio and saturation in pulse oximetry is related to tissue optical properties, and that the sensitivity to varying perturbation induced artifacts can be affected by choice of emitter wavelengths. For high oxygen saturations, the choice of 660 nm and 890 nm band emitters is well suited for stable pulse oximetry calculations, while 700-790 nm and 890 nm band emitters perform better at low saturations. Other wavelength combinations may be chosen from elsewhere in the visible and near infrared portion of the spectrum by following an analysis similar to the one described here. Currently, however, overall instrument design considerations (e.g., electronic signal-to-noise and potential shunting of light with narrowly spaced components in a reflectance probe) favor the use of the wavelengths discussed. By using the analysis described, other improvements to pulse oximetry are possible. FIGS. 19-23 illustrate the results of these tests for several prototype sensors.
FIGS. 26A and 26B are front and side views of a single package containing emitters 112 and 114 of FIGS. 24 and 25. Both emitters are encapsulated in a single semiconductor package, to make the package more compact to provide the miniaturization which is advantageous for a fetal sensor application. In the embodiment of FIG. 26A, emitter die 112 is mounted via a conductive epoxy 130 to a substrate 132. Substrate 132 takes the form of a metal plating, an exterior portion 134 of which forms the outside lead to the package. Emitter 114 is mounted on top of metal substrate 136, an exterior 138 of which forms the second lead.
The electrical connection to emitter 114 is provided through lead 138 on one side up through the conductive epoxy, and through the other side via a wire bond 140, which connects to the other lead 134. Similarly, lead 134 connects through conductive epoxy 130 to the second emitter 112, with the other side of emitter 112 connected via a wire bond 142 to lead 138. Accordingly, as can be seen, applying a voltage with a first polarity to the two leads 134 and 138 will turn on one of the emitters, and turn off the other, while reversing the polarity will reverse which emitter is turned on and which emitter is turned off. Both of the emitters and their corresponding substrates are encapsulated in a package 144 which may, for instance, be plastic.
FIG. 26B is a side view showing the encapsulated package 144 from the side, and illustrating the emitting light 146 from emitters 112, 114. The structure of FIGS. 26A-26B is compact and usable for a fetal application. Preferably, the distance between the centers of the two emitter dies 112 and 114 is less than 2mm. This way the package's wiring allows the package to have two leads, as opposed to four leads which would be required by using two separate emitter packages.
As an alternative to using a far red and an infrared LED, other methods for producing selected light spectrums of two different wavelengths can be used. For example, lasers could be used rather than LEDs. Alternately, a white light or other light source could be used, with the wavelength being optimized at the detector. This could be done by using appropriate filters in front of either the light source or the detector, or by using a wavelength sensitive detector. If filters are used, they could be placed in front of alternate detectors or emitters, or filters could be alternately activated in front of a single emitter or detector.
A pulse oximeter for use over a broad saturation range can utilize multiple wavelength pairs (e.g., both 660 nm and 730 nm band emitters coupled with a 900 nm emitter), with the appropriate emitter pair chosen for use in the calculation of SpO 2 based on the estimated value of the oxygen saturation.
Such a pulse oximeter could be implemented with two or more red LEDs, or alternately could be implemented with a single light source and multiple filters, or multiple wavelength sensitive detectors. Different red wavelength spectrums could be utilized, based on the saturation of the patient.
As will be understood by those with skill in the art, the present invention can be embodied in other specific forms without departing from the essential characteristics thereof. The wavelength could be varied while still optimizing in accordance with the present invention. Also, light pipes, light fibers, multiple filters, or multiple detectors could be used in accordance with the concepts of the present invention. Different sensors than the fulcrum structure as set forth in FIG. 25 could be used, such as a bladder structure for inflating and holding the sensor against the fetus. Accordingly, reference should be made to the appended claims for defining the scope of the invention. | A pulse oximeter sensor with a light source optimized for low oxygen saturation ranges and for maximizing the immunity to perturbation induced artifact. Preferably, a red and an infrared light source are used, with the red light source having a mean wavelength between 700-790 nm. The infrared light source can have a mean wavelength as in prior art devices used on patients with high saturation. The sensor of the present invention is further optimized by arranging the spacing between the light emitter and light detectors to minimize the sensitivity to perturbation induced artifact. The present invention optimizes the chosen wavelengths to achieve a closer matching of the absorption and scattering coefficient products for the red and IR light sources. This optimization gives robust readings in the presence of perturbation artifacts including force variations, tissue variations and variations in the oxygen saturation itself. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a method of preparing orthotrifluoromethyl aniline from trifluoromethyl benzene. Orthotrifluoromethyl aniline is industrially important because it is used as an intermediate in the synthesis of dyestuffs.
Kemichi Fukui et al. (Chemical Abstracts 1960 4430 b) describe the nitration of trifluoromethyl benzene to obtain metanitrotrifluoromethyl benzene, which is converted into metatrifluoromethyl aniline. The acetylation of the aniline compound by acetic acid gives metaacetylaminotrifluoromethyl benzene, the nitration of which yields 2-nitro-5-acetyl-aminotrifluoromethyl benzene.
The latter, by hydrolysis, gives 2-nitro-5-amino-trifluoromethyl benzene. The elimination of the amine group is effected by reductive diazotation, which makes it possible to obtain orthonitrotrifluoromethyl benzene, the reduction of which leads to orthotrifluoromethyl aniline.
The main drawback of this method is its length. Seven steps (not including separation and purification steps) are necessary to obtain the desired product from the trifluoromethyl benzene starting material. Furthermore, as is well known, diazotation is a difficult procedure. In addition, purification operations are necessary after most of the steps. Finally, yields are limited.
L. M. Yagupolsky and N. I. Manko (Chemical Abstracts 1954 8194 e) disclose treating orthotrifluoromethyl benzamide with sodium hypobromite in accordance with the Hoffman degradation reaction. One drawback of this reaction is the well known possibility of forming N-bromoamines, which are explosive. Furthermore, the raw material used in this process is not readily available industrially.
SUMMARY OF THE INVENTION
The present invention avoids the above-described disadvantages and provides a safe method of making orthotrifluoromethyl aniline. Broadly, the method is as follows. Trifluoromethyl benzene is reacted with gaseous chlorine in the presence of a chlorination catalyst until at least 90% of the trifluoromethyl benzene has been consumed. The resultant crude mixture is nitrated by a mixture of sulfuric acid and nitric acid until the chlorotrifluoromethyl benzenes previously formed disappear. After settling of and washing the organic phase, it is subjected to two-stage hydrogenation. First, hydrogenation is carried out under pressure in the presence of a hydrogenation catalyst consisting of Raney nickel and/or Raney nickel doped with chromium, in organic solvent until complete disappearance of the chloronitrotrifluoromethyl benzenes present. The second hydrogenation is carried out in the presence of an additional amount of Raney nickel and in the presence of at least one alkaline base. Finally, the orthotrifluoromethyl aniline is separated by distillation from the crude reaction mixture.
The ease of obtaining orthotrifluoromethyl aniline by the present process is very surprising, for the following reasons. The nearly complete chlorination of trifluoromethyl benzene leads, as is known, to a mixture of monochloro and dichloro derivatives. In addition to the metachlorotrifluoromethyl benzene obtained in preponderant proportion and the para and ortho derivatives, isomers of dichlorotrifluoromethyl benzenes may be present in amounts of up to 20 to 25%.
This large proportion of dichloro products would lead one skilled in the art to either remove them or minimize their formation. The former involves distillation operations, which complicate the technique and increase the cost of manufacture. In the latter case, it is necessary to decrease the rate of conversion of the trifluoromethyl benzene and, therefore, to introduce a distillation step after the chlorination to remove the unreacted trifluoromethyl benzene. Either way, such a process would seem to present serious drawbacks.
However, contrary to the expectations of one skilled in the art, applicants have discovered that the dichloro compounds obtained at the end of the first step are advantageous because in the rest of the process they favor the formation of orthotrifluoromethyl aniline, the desired product. In other words, the step which one skilled in the art would have expected to be the greatest obstacle to the adoption of such a method has been discovered by applicants to be a step which favors the process technically and economically. In fact, with this process the yield is increased and the process simplified due to the absence of intermediate distillations.
More specifically, applicants have found that nitration of the dichloro products can be carried out under the same conditions as for the monochloro derivatives. Furthermore, applicants have discovered that the reduction and hydrodechlorination of the nitrodichloro derivatives can be carried out under relatively mild conditions, a fact that had not been established previously.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with one preferred embodiment of the invention, for the first step, the chlorination catalyst is selected from the group consisting of ferric chloride, antimony pentachloride and the metals, iron and antimony, which are capable of producing in situ these two compounds. These may be used alone or in combination. Antimony pentachloride and ferric chloride are preferred.
The catalyst concentration is usually from about 0.1% to about 10% by weight, based on the trifluoromethyl benzene employed. Preferably, this percentage is from about 0.5 to about 5%.
Chlorination is generally carried out without solvent, although an organic solvent may be used. Chlorination is effected at a temperature from about 0° to about 100° C. and preferably from about 10 ° to about 80° C. Atmospheric pressure is preferred although pressures higher or lower than atmospheric pressure are still within the scope of the invention. Conversion of the trifluoromethyl benzene is preferably greater than 95% and may reach 100%.
For the nitration (second) step, solvent is not usually employed although the use of solvent is not excluded from the scope of the invention. The acids, HNO 3 and H 2 SO 4 , are used in such amounts that the weight ratio of the sulfuric acid to the chlorotrifluoromethyl benzenes initially present in the reaction medium is from about 0.5/1 to about 5/1 and preferably from about 0.7/1 to about 2/1 and the weight ratio of nitric acid to the chlorotrifluoromethyl benzenes initially present is from about 0.5/1 to about 5/1 and preferably from about 0.7/1 to about 2/1.
Nitration is effected at a temperature of from about 0° to about 80° C. and preferably from about 10° to about 60° C. Atmospheric pressure is preferred although other pressures are still within the scope of the invention. Decanting and washing the organic phase (third step) after the nitration reaction can be effected with water and caustic soda.
In accordance with a preferred embodiment of the invention, the first hydrogenation (fourth step) is carried out under a hydrogen pressure of from about 10 to about 50 bars and preferably from about 10 to about 30 bars. The temperature is from about 20° to about 100° C. and preferably from about 40° to about 80° C. The solvent is selected from the group consisting of methanol, ethanol, and propanol, with methanol being preferred.
This first hydrogenation is carried out in the presence of Raney nickel and/or Raney nickel doped with chromium as a hydrogenation catalyst. Raney nickel doped with chromium means Raney nickel containing from about 0.5 to about 5% by weight of chromium. The catalyst is used in such amount that its concentration is from about 3 to about 10% by weight based on the chloronitrotrifluoromethyl benzenes present. Preferably, this percentage is from about 4 to about 8%.
The second hydrogenation (fifth step) is carried out with the same temperature, hydrogen pressure, and solvent as the first hydrogenation. At least one mole of alkali base per mole of chlorotrifluoromethyl benzene initially present is introduced into the reaction medium for the second hydrogenation. Caustic soda or caustic potash is used as the alkali base, with caustic soda preferred.
During the second hydrogenation, from about 8 to about 20% by weight of Raney nickel based on the chloronitrotrifluoromethyl benzenes initially present is also introduced in one or more additions. Preferably, this percentage is from about 9 to about 15%.
Other characteristics and advantages of the present invention will become more evident from the following examples, which are in no way to be considered as constituting a limitation on the invention.
EXAMPLE 1
Twenty-nine and two-tenths kg of trifluoromethyl benzene and 292 g of antimony pentachloride are introduced into a reactor which is equipped with an agitator, a gas injector, and a hydrochloric-acid absorber. Gaseous chlorine at 20° C. is then introduced for 8 hours. After washing with water, 35.340 kg of mixture is obtained with the following vapor-phase chromatographic analysis:
______________________________________trifluoromethyl benzene: 4%metachlorotrifluoromethylbenzene: 70.6%parachlorotrifluoromethylbenzene: 5.8%orthochlorotrifluoromethylbenzene: 3%dichlorotrifluoromethyl benzenes(three isomers): 16.6%______________________________________
Conversion of the trifluoromethyl benzene is 95% and the overall yield is 96%.
Fifteen and ninety-four hundredths kg of concentrated sulfuric acid (97%) and 15.940 kg of fuming nitric acid are introduced into an agitated reactor. This acid mixture is cooled to 10° C. and then 18.05 kg of the previously obtained crude mixture of trifluoromethyl benzene, chlorotrifluoromethyl benzenes, and dichlorotrifluoromethyl benzenes are added with agitation over the course of one hour while maintaining this temperature.
When the addition has been completed, the mixture is brought to 50° C. and held at that temperature for 6 hours. The organic phase is poured off and washed with water, with 10% caustic soda, and then again with water. In this way, 21.62 kg of a mixture is obtained with the following vapor-phase chromatographic analysis:
______________________________________chlorotrifluoromethyl benzene: none detectablenitrotrifluoromethyl benzene: 3.9%chloronitrotrifluoromethylbenzenes (four isomers): 82.2%dichloronitrotrifluoromethylbenzenes (four isomers): 13.9%______________________________________
Conversion of the chlorotrifluoromethyl benzenes is 100% and the overall yield is 96%.
One and four-tenths liters of methanol and 50 g of Raney nickel are put into an agitated autoclave. This mixture is placed under 20 bars of hydrogen at 20° C. and agitated for 15 minutes. One and forty-six hundredths liters of methanol and 1 kg of the organic phase that was previously obtained are then added. Hydrogenation is effected at 80° C. under 20 bars. At the end of 1.5 hours, analysis by vapor-phase chromatography reveals that all of the chloronitrotrifluoromethyl benzenes have been consumed. The mixture is cooled to 50° C. and 622 g of 30.8% caustic soda is added. The mixture is then agitated for 15 minutes under 20 bars of hydrogen.
Fifty g of Raney nickel are then added and a second hydrogenation is effected under 20 bars of hydrogen at 50° C. for two hours. A further 50 g of Raney nickel are added and the hydrogenation is continued for an 2 hours more. The reaction is then complete. After filtration, concentration, and washing with water, 684 g of a mixture of amines is obtained having the following composition:
______________________________________orthotrifluoromethyl aniline: 77.2%metatrifluoromethyl aniline: 20.5%paratrifluoromethyl aniline: 2.3%______________________________________
This mixture is subjected to distillation in a 20-plate column with a reflux ratio of 29/1 under an overhead pressure of 50 mm Hg. A total of 522 g of orthotrifluoromethyl aniline are obtained at a concentration of more than 99% corresponding to a yield of 99%.
EXAMPLE 2
Seven and three-tenths kg of trifluoromethyl benzene, 41 g of ferric chloride, and 20 g of iron are introduced into the reactor of Example 1. Chlorine is then added as in Example 1 at 20° C. for six hours. After washing with water, 9160 g of a mixture is obtained having the following analysis by vapor-phase chromatography:
______________________________________trifluoromethyl benzene: 1.7%metachlorotrifluoromethylbenzene: 66.4%parachlorotrifluoromethylbenzene: 6.1%orthochlorotrifluoromethylbenzene: 2.6%dichlorotrifluoromethylbenzenes: 24.3%______________________________________
Conversion of the trifluoromethyl benzene is 98% and the overall yield is 98%.
Two thousand seven hundred fifty-three g of the above crude mixture are added to an agitated reactor. The mixture is cooled to 10° C. and a mixture of fuming nitric acid (1700 g) and concentrated (97%) sulfuric acid (2350 g) is added under agitation at this temperature over the course of one hour. The mixture is then held at 80° C. for six hours. The organic phase is poured off and washed with water, 10% caustic soda, and then again with water. In this way, 3290 g of a mixture are obtained with the following composition:
______________________________________chlorotrifluoromethyl benzene: none detectablenitrotrifluoromethyl benzene: 1.8%chloronitrotrifluoromethylbenzenes: 74.8%dichloronitrotrifluoromethylbenzenes: 23.4%______________________________________
Conversion of the chlorotrifluoromethyl benzenes is 100% and the overall yield is 96%.
Twenty-nine hundred ml of methanol and 50 g of Raney nickel doped with chromium are added to an agitated autoclave. The pressure is brought to 12 bars of hydrogen at 50° C. with agitation for 15 minutes. One thousand g of the nitration product previously obtained are added under these conditions during 1.75 hours. The mixture is then maintained at 50° C. under 12 bars of hydrogen with agitation for an additional 1.5 hours. By this time, all of the chloronitrotrifluoromethyl benzenes have been consumed.
Six hundred thirty g of 31.1% caustic soda are then added and agitation is carried out at 50° C. and 12 bars of hydrogen for 15 minutes. Fifty g of Raney nickel are added and hydrogenation is effected for 2 hours at 50° C. under 12 bars of hydrogen. Another 50 g of Raney nickel are added and hydrogenation is continued for 3 hours under the same conditions. The reaction is then complete.
After filtration, concentration, and washing with water, 670 g of a mixture are obtained with the following composition:
______________________________________orthotrifluoromethyl aniline: 76.7%metatrifluoromethyl aniline: 21.2%paratrifluoromethyl aniline: 2.1%______________________________________
This mixture is distilled as in Example 1. Four hundred ninety-eight g of orthotrifluoromethyl aniline at a concentration of more than 99% are obtained, which corresponds to a distillation yield of the orthotrifluoromethyl aniline of 97%.
EXAMPLE 3
Seven and three-tenths kg of trifluoromethyl benzene and 62.4 g of antimony are added to the reactor of Example 1. Chlorine is then added as in Example 1 at 20° C. for 3.5 hours. After washing with water, 9170 g of a mixture are obtained with the following analysis by vapor-phase chromatography:
______________________________________trifluoromethyl benzene: 0.7%metachlorotrifluoromethylbenzene: 65.5%parachlorotrifluoromethylbenzene: 5.2%orthochlorotrifluoromethylbenzene: 1.5%dichlorotrifluoromethylbenzenes: 27.1%______________________________________
Conversion of the trifluoromethyl benzene is 99.1% and the overall yield is 97%.
Two thousand seven hundred fifty-three g of the preceding crude mixture are then added to an agitated reactor. The reactor contents are cooled to 10° C. and a mixture of fuming nitric acid (1700 g) and concentrated (97%) sulfuric acid (2350 g) is introduced under agitation at 10° C. over the course of one hour.
The mixture is then brought to 80° C. and held there for six hours. The organic phase is poured off and washed with water, 10% caustic soda, and then again with water. In this way, 3200 g of a mixture are collected with the following composition:
______________________________________chlorotrifluoromethyl benzene: none detectablenitrotrifluoromethyl benzene: 0.7%chloronitrotrifluoromethylbenzenes: 72.9%dichloronitrotrifluoromethylbenzenes: 26.4%______________________________________
Conversion of the chlorotrifluoromethyl benzene is 100% and the overall yield is 94%.
Twenty-nine hundred ml of methanol and 50 g of Raney nickel doped with chromium are added to an agitated autoclave. The mixture is brought to 50° C. under 12 bars of hydrogen with agitation during a period of 15 minutes. Under these conditions, 1000 g of the nitration product previously obtained are added over the course of 1.75 hours. The mixture is maintained for an additional 1.5 hours at 50° C. under 12 bars of hydrogen with agitation. It is found that all of the chloronitrotrifluoromethyl benzenes have been consumed. Six hundred thirty g of 31.1% caustic soda are added and agitated at 50° C. under 12 bars of hydrogen for 15 minutes. Fifty g of Raney nickel are added and hydrogenation carried out for two hours at 50° C. under 12 bars of hydrogen. Another 50 g of Raney nickel are added and the hydrogenation continued for 3 hours under the same conditions. The reaction is then complete.
After filtration, concentration, and washing with water, 660 g of mixture obtained are with the following composition:
______________________________________orthotrifluoromethyl aniline: 78.2%metatrifluoromethyl aniline: 19.7%paratrifluoromethyl aniline: 2.1%______________________________________
This mixture is distilled in the same manner as in Example 1. Five hundred five g of orthotrifluoromethyl aniline of a concentration of more than 99% are obtained, which corresponds to a distillation yield of orthotrifluoromethyl aniline of 98%.
Variations and modifications will be apparent to one skilled in the art and the claims are intended to cover all variations and modifications that fall within the true spirit and scope of the invention. | A process for preparing orthotrifluoromethyl aniline from trifluoromethyl benzene is disclosed. The steps are (a) reacting the trifluoromethyl benzene with gaseous chlorine in the presence of a chlorination catalyst until at least 90% of the trifluoromethyl benzene is consumed; (b) nitrating the crude mixture from step (a) using a mixture of sulfuric acid and nitric acid until disappearance of the chlorotrifluoromethyl benzenes; (c) settling and washing the organic phase from step (b); (d) subjecting the organic phase from step (c) to a first hydrogenation under pressure in the presence of a hydrogenation catalyst consisting of Raney nickel and/or Raney nickel doped with chromium, in an organic-solvent medium until complete disappearance of the chloronitrotrifluoromethyl benzenes; (e) subjecting the mixture from step (d) to a second hydrogenation in the presence of an additional amount of Raney nickel and in the presence of at least one alkaline base; and (f) removing the orthotrifluoromethyl aniline by distillation from the reaction mixture. | 2 |
TECHNICAL FIELD
[0001] The present invention generally relates to a lighting system where individuals light sources can be removed and/or replaced from a strand of light sources.
BACKGROUND
[0002] Generally, theater and auditorium lighting systems incorporate low voltage lighting strips within extrusions that are then placed on stairs, chairs and walkways in order to illuminate walking areas for patrons and ushers. The prior art has contemplated different ways of arranging the light strips. Typically, the lighting strips are made up of wires soldered to light-emitting diodes (“LEDs”) or LED circuit boards. A number of lighting systems are known including U.S. Pat. Nos. 6,283,612, 6,145,996, and 6,116,748.
[0003] These systems, however, do not generally provide for the efficient replacement of an LED that has malfunctioned or burned out. It is often cumbersome to replace an LED from a lighting strip and often the entire lighting strip must be replaced and not just the damaged LED. The present invention provides an easier and safer method of replacing one or more LEDs in a lighting strip.
SUMMARY OF THE INVENTION
[0004] The present invention generally relates to a lighting fixture where individual light sources can be removed and/or replaced from a strand of light sources. The preferred embodiment of the light fixture comprises a plurality of light sources strung together by a plurality of wire assemblies. Each light source preferably has one end of a tongue and groove connector where the opposing end of the connector is attached to an end of a wire assembly. The strand of light sources is then placed within a lens component, preferably an extrusion. The lens component is connected to a base component; wherein the plurality of light sources are mounted to the base component and contained within the lens component. The fixture can be mounted to, inter alia, a wall, a chair, or a railing in an area to be lit by the fixture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings.
[0006] [0006]FIG. 1 is a side cross sectional view of a preferred embodiment of the invention.
[0007] [0007]FIG. 2 is a perspective view of a preferred embodiment strand of LEDs and wire assemblies.
[0008] [0008]FIG. 3 is a close-up top view of the preferred embodiment of the connectors.
[0009] [0009]FIG. 4 is a perspective close-up view of an LED and board with the preferred embodiment of connectors.
[0010] [0010]FIG. 5 is an end view of a preferred embodiment of the wire assembly.
[0011] [0011]FIG. 6 is a view of a preferred embodiment of the invention in use casting light on stairs.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein specifically to provide an improved light fixture.
[0013] Referring now to FIG. 1, a side cross sectional view of the preferred embodiment of the improved light fixture 100 is shown. The light fixture 100 of the present invention can be used in, inter alia, theater and auditorium lighting systems to illuminate walkways and corridors for patrons and ushers. Preferably, the fixture 100 comprises two extruded parts, a lens component 20 and a base component 30 . Each extrusion is preferably made of polyvinylchloride (PVC) but can also be made of polycarbonate. The lens component 20 can also comprise acrylic.
[0014] The lens component 20 preferably comprises two parts, a shield 21 and a lens 22 . Preferably, these two parts are co-extruded. The shield 21 is made of an opaque material such that it prevents light from emitting from the light fixture 100 except through the lens 22 that is generally made of a transparent material. As such, the light emitted from the light source 10 through the lens 22 will shine onto the walkways and corridors that need illumination rather than into the eyes of patrons, performers and/or ushers.
[0015] The lens component 20 of the fixture 100 also preferably supports a strand of light sources 10 . In the preferred embodiment, the light source 10 (an LED on a circuit board is shown in FIG. 1) is mounted to the lens component 20 by sliding the circuit board of the light source 10 into a set of notches on the lens component 20 . The light source 10 is therefore held at a set angle to the lens 22 in the lens component 20 .
[0016] The lens component 20 and the base component 30 preferably connect to one another via a sliding or snap-lock mechanism. As such, the entire fixture 100 can be mounted on a variety of surfaces such as stairs, chairs, walls or walkways via the base component 30 as shown in the preferred use depicted in FIG. 6. When the base component 30 is mounted to a surface, the lens 22 of the lens component 20 is preferably perpendicular to the base component 30 so that the light emitted from the light source 10 shines on to a desired area for illumination.
[0017] [0017]FIG. 6 depicts a preferred installation of the invention for illumination of steps 200 . In FIG. 6, the fixture 100 is mounted to a surface 210 near steps 200 . The light sources 10 illuminate the steps 200 . The shield 21 of the lens component 20 shields light from the light sources 10 such that the majority of the illumination from the light sources is cast downward onto the steps 200 rather than up and/or out from the fixture 100 away from the target area for illumination. Preferably, when the fixture 100 is mounted at least 18 inches above the target area to be illuminated, the light from the light sources 10 can cast light up to 48 inches from the mounted fixture 100 . This is approximately a seventy degree (70°) angle of illumination.
[0018] [0018]FIG. 2 shows a perspective view of a preferred embodiment strand of light sources 10 , (LEDs and circuit boards shown), that are mounted within the lens component 20 . Each light source is preferably a high brightness LED of material AlGalnP with super yellow emitted color and a lens color of water clear. The preferred LED model is an Alpinetech LP7615UYC LED.
[0019] Each light source 10 preferably mates to a wire assembly 15 via a connector with polarity-determined geometry. For example, the preferred embodiment described herein uses tongue 13 and groove 14 components. FIGS. 3, 4 and 5 show varying views of a preferred embodiment of these components. The wire assembly preferably comprises wires that are #20 GA AWG FTI 90 degrees C., 300 volts, UL recognized. The wire assemblies are preferably made in pre-determined lengths such as 3, 4 and 6 inches.
[0020] As described below, the polarity-determined geometry of the connectors 11 and 12 help insure that the light source 10 is connected to the strand of lights with the proper polarity. In addition to the tongue and groove arrangement described herein, the connectors 11 , 12 and wire assemblies 15 can be mated with varying shaped connectors that only connect when the light source 10 is aligned to the proper polarity in the strand, e.g. a negative end of one light source 10 connects via a wire assembly 15 to the positive end of another light source 10 . For example, the first connector 11 could be a round shape and the second connector 12 could be square with corresponding wire assembly 15 having ends to receive said connectors 11 , 12 based on their polarity.
[0021] As depicted in the FIGS. 1 - 6 , each light source 10 preferably comprises a first connector 11 on one end and a second connector 12 on the other end of the light source 10 . Each connector 11 , 12 has a tongue component 13 . Each wire assembly 15 has a first end 16 and a second end 17 . Each end 16 , 17 of the wire assembly 15 has a groove component 14 . Each tongue component 13 on the light source 10 mates or slides into an opposing groove component 14 on the wire assembly 15 .
[0022] Thus, light sources 10 are more easily removed and replaced when damaged and/or inoperative. This reduces the possibility of needing the cumbersome process of replacing an entire light fixture or entire strand of light sources as is often necessary in prior art light fixtures due to, inter alia, soldered connections.
[0023] The polarity-determined geometry, as shown here the tongue 13 and groove 14 configuration, provides an advantage regarding the polarity of each light source 10 . Each light source 10 typically requires that the wire assembly 15 be connected properly vis-a-vis the polarity of the connection. For example, the positive and negative terminals of each light source 10 should be connected via wire assembly 15 to the proper positive and negative terminals of light sources 10 adjoining in a strand of light sources 10 such as in FIG. 2. If the polarity of a light source 10 is not properly matched in a strand of light sources, a light source 10 and/or the entire strand can often be rendered, at least temporarily, inoperative.
[0024] [0024]FIG. 3 shows a close up view of a preferred light source, an LED 10 , and the first connector 11 and second connector 12 at opposing ends. A light source 10 preferably has ends with opposing polarity, i.e. positive and negative polarity. Looking to FIG. 4, the tongue component 13 of each connector 11 , 12 is placed in a predetermined position (the top and bottom of the connectors 12 , 11 shown) such that the groove component 14 of the wire assembly 15 must be directed to a similarly situated tongue component 13 . Thus, the groove components 14 on each end of the wire assembly 15 are also placed in pre-determined positions (again, top and bottom position shown in FIGS. 2 and 3.) Thus, the polarity of the strand of lights sources can be properly maintained by matching similarly situated tongue components 13 to groove components 14 . If a wire assembly 15 or light source 10 is twisted or turned so that the proper polarity would not be maintained in the strand then the tongue 13 and groove 14 components will not match and a connection of faulty polarity is unlikely to be made.
[0025] This improvement assists with both the manufacture of strands and replacement of light sources 10 . This improvement avoids the common problem in which the wires were soldered to the light sources with the wrong polarity during manufacture of the strands. This often caused the fixtures to be nonfunctional.
[0026] For replacement purposes, in a situation where the improved light fixture 100 contains a malfunctioning light source 10 , this invention is useful for easier and safer replacement of light sources. The lens component 20 can be disconnected from the base component 30 . The malfunctioning light source 10 is unmated from the adjacent wire assemblies 15 and a new functioning light source 10 can be placed in the strand. The tongue 13 and groove 14 components will only fit together if the polarity is correct, thus the chance of faulty replacement due to improper polarity is reduced. As such, the new light source 10 can be replaced more easily, quickly and properly without the need for soldering or replacement of entire strands of lights.
[0027] In each of the above embodiments, the different positions and structures of the present invention are described separately in each of the embodiments. However, it is the full intention of the inventor of the present invention that the separate aspects of each embodiment described herein may be combined with the other embodiments described herein. Those skilled in the art will appreciate that adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein. | The present invention generally relates to a lighting fixture where individual light sources can be removed and/or replaced from a strand of light sources. The preferred embodiment of the light fixture comprises a plurality of light sources strung together by a plurality of wire assemblies. Each light source preferably has one end of a tongue and groove connector where the opposing end of the connector is attached to an end of a wire assembly. The strand of light sources is then placed within a lens component, preferably an extrusion. The lens component is connected to a base component; wherein the plurality of light sources are mounted to the base component and contained within the lens component. The fixture can be mounted to, inter alia, a wall, a chair, or a railing in an area to be lit by the fixture. | 5 |
BACKGROUND OF THE INVENTION
[0001] Magnetic devices, such as DC to DC power supplies, isolation transformers, voltage step down transformers, and inductors are needed in various electronic circuits. It is time consuming and difficult to insert discrete packaged transformer and inductor components onto a printed circuit board (i.e., PCB), and the high profile of these parts is not compatible with many types of finished products, such as cell phones, personal digital assistants (i.e., PDAs), and notebook computers. Further, the wave soldered thru hole connections, or the surface mount soldering pads, required for attaching these transformers or inductors to the PCB provide further opportunities for the introduction of fatal manufacturing defects, especially with current PCBs typically having as many as 20 conductive layers.
[0002] To solve the discrete component problem for transformers and inductors on PCBs discussed above, it is known to use the various individual conductor layers that comprise a typical PCB to create planar electrical coils through which electrical currents are propagated to create a magnetic field. By stacking such coils, for example one coil per conductor layer of the PCB, one on top of the other, and by connecting the individual coils together by means of what are known as vias in the PCB, it is possible to create stacked inductive coils having reasonably small size and sufficient total inductance values.
[0003] By interleaving the coils and separating the electrical connections into two groups, one group, for example the odd numbered layers, as a primary winding, and the second group, for example the even numbered layers, as the secondary winding, then the stacked inductors may be formed into a power transformer. To illustrate the transformer formation with a ten to one step down voltage transformation, the first layer would be a primary ten turn winding, the second layer would be a secondary one turn winding, the third layer would be another primary ten turn winding, and so on through as many of the PCB layers as are desired to achieve the necessary current and magnetic field, or until the last available PCB layer is reached.
[0004] However, there is a problem with the planar coils described above. The need to make electrical connections through the insulating layers separating the conductive layers of the PCB disrupts the direction and flow of electrical current and creates what is known as leakage inductance. Leakage inductance reduces the magnetic coupling between windings of the transformer, and increases thermal management problems and consequently reduces component lifetime. The need to make layer to layer contact also results in increased length of the conductor runs, and consequent increased winding resistance, and thus again increased thermal management problems.
[0005] Therefore, a problem exists with efficiently making contact between planar coils, and in laying out the coils to maximize the layer to layer overlap, and thus the total inductance, while minimizing the total coil length and the number of contacts outside the magnetic field area.
SUMMARY OF THE INVENTION
[0006] An apparatus and method for providing planar magnetic fields for PCB inductance and voltage transformation is presented having a typical PCB with multiple conductive layers electrically separated by insulating layers. A set of primary windings and secondary windings having a specified order are arranged on the layers of the PCB to form the magnetic device. In a preferred embodiment of the invention, a first primary winding is created on a first one of the conductive layers of the PCB, a first secondary winding is created on a second conductive layer of the PCB directly below the first winding. A second primary winding is created on the third conductive layer of the PCB, and a second secondary winding is created on a fourth conductive layer of the PCB, continuing in this fashion until each one of the desired number of primary and secondary windings are created within a PCB.
[0007] In another embodiment of the invention, the odd numbered primary windings spiral inward toward a core region in either a clockwise or counter clockwise direction, and the even numbered primary windings spiral outward from the core region in the same direction as the odd numbered primary windings. Also the odd numbered secondary windings spiral inward toward the core region, and the even numbered secondary windings spiral outward from the core region in the same direction as the odd numbered secondary windings. In an alternate embodiment of the invention, the odd numbered secondary windings spiral outward from the core region rather than inward, and the even numbered secondary windings spiral inward.
[0008] In a further embodiment of the invention, the number of conductive PCB layers is smaller than the needed number of primary and secondary windings. The remaining number of required windings are created on one or two small multilayered PCBs, which are attached to the surface of the PCB, typically directly above or below the PCB winding, in order to continue the coil stack.
[0009] In another embodiment of the invention, all of the electrical connections between coils on different PCB layers are made inside the magnetic field area of the coil stack to reduce leakage inductance.
[0010] In yet another embodiment of the invention, the odd numbered ones of the coils are connected together in series to form the primary windings of a transformer, and the even numbered ones are electrically connected together in parallel to form the secondary windings of the transformer. In an alternate embodiment the secondary windings are single turn coils.
[0011] PCB winding technique is presented that minimizes the number and length of layer to layer interconnections, and provides the interconnections inside the magnetic field of a magnetic device built on a PCB. This improves the high parasitic losses found in present planar magnetic winding techniques. The improvement is due to better usage of the area of conductive material (i.e., Copper) inside the magnetic field area since less conductive material is used for layer to layer interconnection. This is accomplished by spiraling the first layer inward towards the magnetic core, then the next interconnected layer down spirals outward away from the core, etc. By making all of the magnetic connections inside the magnetic field area, the usual leakage inductance is minimized, and reducing the overall length of the windings by not leaving the magnetic field area to make connects, the electrical resistance of the winding is reduced, thereby reducing parasitic current loss and unwanted component heating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0013] [0013]FIG. 1 is a top view of a first conductor layer;
[0014] [0014]FIG. 2 is a top view of a second conductor layer;
[0015] [0015]FIG. 3 is a top view of a third conductor layer;
[0016] [0016]FIG. 4 is a top view of a fourth conductor layer;
[0017] [0017]FIG. 5 is a top view of a fifth conductor layer;
[0018] [0018]FIG. 6 is a top view of a sixth conductor layer;
[0019] [0019]FIG. 7 is a top view of a seventh conductor layer;
[0020] [0020]FIG. 8 is a top view of a eighth conductor layer; and
[0021] [0021]FIG. 9 is a transformer circuit schematic of a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] A description of preferred embodiments of the invention follows.
[0023] The invention will be described with reference to an illustrative example of a ten to one voltage step down transformer. The specific direction, placement and number of turns of the spiral coils depends upon the device characteristics desired, and the invention is not limited to the specific examples shown, but rather the principles of the invention may be applied to other types of planar coil inductors, transformers and other magnetic devices.
[0024] [0024]FIG. 1 shows a top view of a first conductor layer 10 disposed typically on the top layer of a PCB 12 , or alternatively on the first buried conductor layer inside the PCB. The conductor 10 may be intended for either a magnetic device such as an inductor or for a transformer. In the case of a inductor, all of the various conductor layers such as 10 will be wound having as many turns of the coil as possible on each layer, compatible with the required winding resistance, the PCB spacing requirements and allowable PCB area. To increase the total inductance of an inductor it is possible to insert a ferrite material into the central axis of the coil. In the present preferred illustrative embodiment of the invention, the PCB 12 has a hole 14 (shown with shading) disposed to accept a ferrite core in all of the PCB layers, but this is not a requirement of the invention and there are other embodiments of the invention that will not allow for the added PCB expense resulting from the hole fabrication.
[0025] The conductor layer 10 is preferably formed into a coil 16 , in this illustrative embodiment of the invention, having a clockwise inward spiral toward the central core 14 . The first coil 16 in this example is shown as a first primary winding of an illustrative ten to one voltage step down transformer. The first primary winding, coil 16 , shown as having 2.5 turns, has a primary current input at via 18 , from an outside current source, not shown. The first primary coil 16 leaves the first conductor layer 10 at via 20 , which passes through the PCB 12 second conductive layer without making electrical contact in this illustrative embodiment, and electrically connects to the third conductive layer. Notice that the via 20 is within the magnetic field delineated on the inside by the hole 14 in the PCB 12 , and on the outside by the edge of the coil 16 . This arrangement reduces what is known as leakage inductance.
[0026] Notice that there are unused vias 22 , 24 , 26 , 32 and 34 . In PCB manufacturing it is simpler and cheaper to have all vias pass completely through the entire board, and only make contact to those vias that are needed on each layer. This results in a certain amount of wasted space and lost coil to coil area as may be seen by the lost conductor area of coil 16 in the region of via 22 . This lost conductor area reduces the total inductance of the coil and maybe at least partly eliminated by the use of what are known as blind vias in the PCB. However blind vias increase the overall PCB cost.
[0027] [0027]FIG. 2 shows a top view of a second conductor layer 30 on the next lower conductor layer of PCB 12 . In this illustrative embodiment of the invention, the second layer 30 is a first secondary winding of a transformer. In this example of a ten to one voltage reduction transformer, the secondary winding 30 is a single turn having an input contact at 32 , and an output contact at 34 . Since the illustration has only a single turn, there is consequently no spiral, but in an alternative embodiment of a simple inductor, the coil 30 would typically have 2.5 windings in a clockwise direction, as did the first coil 16 in FIG. 1. Notice that the present example has no electrical contact between the second coil 30 and the first coil 16 since the primary and secondary winding of a transformer may not have any direct electrical connection. However, in an alternative embodiment of an inductor, the second coil 30 would typically be connected to the same via 20 as the first coil 16 discussed in the first figure to provide a continuous coil.
[0028] [0028]FIG. 3 shows a top view of a second primary coil 40 constructed on a third conductor layer 42 . The second primary coil 40 is a 2.5 turn clockwise outward spiral beginning at via 20 and ending at via 24 . Notice that the end of the first primary coil 16 of FIG. 1, and the beginning of the second primary coil 40 of FIG. 2, are both at via 20 , and thus the coil 40 is connected in series with the coil 16 , effectively providing a total of five turns for the primary side of the transformer.
[0029] [0029]FIG. 4 shows a top view of a second secondary coil 50 having an input at 32 and an output at 34 . Notice that the first and the second coils 30 , 50 of the secondary side of the illustrative transformer are both connected to the same inputs and outputs, and are thus connected in parallel, providing greater current capability on the voltage step down side of the illustrative transformer.
[0030] [0030]FIG. 5 shows a top view of a third primary coil 60 , again having 2.5 turns in a clockwise inward spiral, starting from via 24 and ending at via 22 . Thus coil 60 starts where the second primary coil 40 ends, and is therefore connected in series with the first and the second primary coils 16 , 40 in series, providing 7.5 turns in the primary coil. Notice that the example has the via 24 connecting the second and third primary coils placed a little outside the magnetic field area. This can be easily changed by placing via 24 in a notch in the coil 60 at location 62 , however this will result in increased current resistance. The tradeoff must be resolved based upon the specific requirements of each magnetic device in the specific circuit design.
[0031] [0031]FIG. 6 shows a top view of a third secondary coil 70 , again having a single turn connected in parallel with the first and second secondary coils 30 , 50 at vias 32 and 34 . In the illustrative embodiment of this example the parallel connection of the single turn secondary coils 30 , 50 , 70 result in an effective single turn secondary side of the voltage step down transformer, but having greater current handling capability.
[0032] [0032]FIG. 7 shows a top view of a fourth primary coil 80 , again having 2.5 turns spiraling outward in a clockwise direction starting from via 22 , where the third primary coil 60 ended, and ending at output via 26 . The four coils 16 , 40 , 60 , 80 , each having 2.5 turns, connected in series results in a single ten turn primary side to the transformer.
[0033] [0033]FIG. 8 shows a top view of a fourth secondary coil 90 having a single turn and connected to the previous three secondary coils 30 , 50 , 70 at vias 32 and 34 , resulting in a parallel connection and a single turn secondary side to the illustrative transformer having four times the current carrying capability. FIG. 8 also shows primary current input line 92 attached to the primary coil input by via 18 , and primary coil current output 94 , connected by via 26 .
[0034] [0034]FIG. 9 is a circuit schematic showing all four primary windings 16 , 40 , 60 , 80 and all four secondary windings 30 , 50 , 70 , 90 of the preceding eight figures, with all of the numbering having the same meanings. Following the overall flow of the primary current coils from the main input line 92 , to via 18 and through 2.5 inward clockwise spiraling turns on first primary coil 16 to via 20 past the second layer 30 and connecting to the third layer, which is the second primary coil 40 . Coil 40 spirals outward 2.5 turns in a clockwise direction to via 24 , and hence bypassing layer 4 to connect in series with layer 5 , the third primary coil 60 , which spirals clock wise inward to via 22 . Via 22 leads past layer 6 and connects to coil 80 on layer 7 , the fourth primary coil in the illustrative transformer. Coil 80 again spirals clockwise out with 2.5 turns and ends at via 26 , which leads to the primary coil output at line 94 . This results in ten total coil turns, and is the primary coil in the illustrative ten to one voltage set down transformer. The secondary coil is more easily seen since all four single turn coils 30 , 50 , 70 and 90 connect to the input line at via 32 , and output line at via 34 . This results in an effective single turn coil for the secondary side of the transformer.
[0035] The alternating inward and outward spirals of adjacent coils results in the maximum possible coil to coil overlap and improved mutual inductance. The illustration uses a clockwise direction to the spirals, but either direction is acceptable as long as all spirals are in the same direction to maximize overlap. The spirals may be run in alternating directions if maximizing the inductance is not the design intention. The alternation of inward with outward spirals results in the shortest possible coil to coil interconnection distance, and consequently the minimum leakage inductance and winding resistance. Generally it is likely that the first coil will spiral inward and the last coil will spiral outward in order to shorten the input and output lead lengths, but this is not a requirement of the invention.
[0036] From the above description of a preferred embodiment of a transformer, it is simple to see the application of the invention to a simple inductor. In the case of an inductor the coils would all be connected directly together in either the series connection shown for the primary side of the transformer, or in parallel as shown for the secondary side of the transformer, depending upon the design requirements for larger inductance or for larger current carrying capability.
[0037] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
[0038] For example, since the number of coils is ordinarily limited by the number of PCB layers available, if additional coils are required by the specific design, an alternate embodiment of the invention increases the available number of coils by attaching small daughter boards of about the maximum dimension of the coils either above, or below, or both, of the coils already on the PCB. In this fashion the number of available coil layers is increased without having to utilize more expensive multilayer PCBs. The area of the PCB around the outside of the coils, and in the center of the coils may be cut away, and the inductance increased by the addition of a ferrite core in the center, and magnetic return fittings connecting the ends of the ferrite core may pass through the cut away outside portions. | A method and apparatus to layout planar magnetic coils on a PCB consists of maximizing the layer to layer overlap, and consequently maximizing total inductance for the given layout area, by spiraling alternating layers inward and outward. A further benefit of the matching opposite spirals is the ability to make the layer to layer electrical contacts within the magnetic field area, thus reducing leakage inductance, and minimizing the wasted extra conductor line length needed to make the connections outside the magnetic field. The reduced conductor line length results in reduced conductor line resistance. The method is applicable to voltage transformers and isolation transformers as well as simple inductors and other magnetic devices. In the transformer case the odd numbered layers are typically connected together in series to provide a larger turn ratio, and the even numbered layers are typically single turns (i.e., no spiral) connected together in parallel to provide more current capability. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an attachment patch for fastening medical accessories such as catheters, cannulae, probes, drainages and the like to the human skin, comprising a carrier material provided with a pressure-sensitive adhesive layer and a protective layer covering the pressure-sensitive adhesive layer and being provided with an upward folding flap to keep the cannula in place.
2. The Prior Art
The typical accessories mentioned above, such as "cannulae" used in medical therapy, need to be reliably fixed. Very rarely, attachment is effected by sewing. In most cases, self-adhesive, partially pre-fabricated, and sometimes individually prepared, fastening strips are used. These known prior art solutions do not offer satisfactory results.
German Patent No. 31 05 187 (A1) describes a fastening means of this type, in which a patch is provided with an attachment strip in the form of a flap. This flap is formed by two parallel cuts starting from the edge of the patch toward the middle portion thereof and can be spirally wound around the cannula to be fixed after having been lifted up. Attachment of the cannula is thus achieved; however, stability and security of the resulting attachment are not satisfactory.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide an attachment patch for fastening medical accessories which ensures simple, safe and stable attachment of the cannula.
This object is achieved according to the present invention by an attachment patch which includes a carrier material provided with a pressure-sensitive adhesive layer and a protective layer covering s id adhesive layer and which is provided with a lift-up flap to fasten the cannula.
This attachment patch is characterized by the following features: the flap is divided into two strips by a center cut, preferably extending beyond the length of the flap; the two strips can be pulled up and wound in opposite helical directions like a spiral around the cannula. The central cut preferably extends beyond the length of the flap, e.g., by one width of one of the resulting fastening strips, that the folding edges running diagonally to the direction of the flap and in opposite direction to each other assume the form of an arrowhead directed toward the end of the flap. Thus, the two strips formed by the central cut and provided with a lateral component, can be folded up mirror-invertedly about the diagonally extending folding lines.
Since the flap is partitioned by three unidirectional cuts starting from one narrow side of the attachment patch or, if the embodiment is a round patch, from any point along the patch edge, two fastening strips, as compared to the known attachment patch, can be wound like a spiral in opposite helical directions around the cannula to be held. Due to the folding edges running diagonally to the outside edges or boundary lines of the fastening strips, there are practically no creases formed when the strips are applied to the cannula.
In a preferred embodiment, the width of the flap consisting of the two fastening strips is determined in such a manner that, in the region of the folding edges, it at least corresponds to the diameter of the cannula to be attached. If the inner edges of the patch in the region of the folding edges are allowed to protrude slightly, even larger cannulae can be fastened.
In a further embodiment of the present invention, the protective layer is divided in such a manner that the protective strips covering the fastening strips may be separated from the rest of the protective layer and, preferably, pulled off individually. By means of this, the adhesive side of the fastening strips is protected from getting uncovered on pulling off the removable protective layer, which is made of suitable known materials, since this could make it more difficult to use and to apply the strips. In addition, the protective layer may optionally protect the actual patch in all directions to facilitate the handling thereof.
The shape and dimensions of the attachment patch according to the present invention are determined from the intended purpose of the application. The carrier material may be a textile fabric or a suitable film material. The known pressure-sensitive adhesives compatible with the skin are used as adhesives.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawing which discloses two embodiments of the present invention. It should be understood, however, that the drawing is designed for the purpose of illustration only and not as a definition of the limits of the invention.
In the drawing, wherein similar reference characters denote similar elements throughout the several views:
FIG. 1 is a top view of the attachment patch according to the present invention prior to application thereof to the skin;
FIG. 2 is a perspective view of an applied patch according to FIG. 1; and
FIG. 3 is a top view of another embodiment of the attachment patch according to the present invention prior to application to the skin.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Turning now in detail to the drawing, FIG. 1 shows a rectangular attachment patch 1 of FIG. 1 being provided with a flap 2 having the fastening strips 3 and 4. The flap 2 is formed by three unidirectional cuts 5, 6 and 7 running substantially parallel to the longitudinal sides 22 and 26 of the patch from one narrow side 24 of the patch 1 toward the other narrow side 25. Cut 6 is preferably along center line C L thereof. The central cut 6 extends beyond the lateral cuts 5, 7 by a length which approximately corresponds to the width of a fastening strip 3, 4 in the region of the folding edges 8, 9. When the fastening strips 3, 4 are pulled up, a folding edge 8 and 9, respectively, is created, each forming an angle A of approximately 45° to the direction of the cut. The folding edge lines 8, 9 together with the central cut 6 form a kind of arrow. Thus, substantially wrinkle-free application of the fastening strips 3, 4 to the cannula 11 shown in FIG. 2 is possible.
Furthermore, the cuts 5 and 7 forming the flap 2 generally run parallel to the longitudinal sides 22 and 26 of the attachment patch. They may also form a symmetric acute angle B 1 or B 2 thereto, preferably to the central cut 6. The acute angles B 1 or B 2 which are formed between the two outer cuts 5, 7 and the central cut 6 may run in such a way that the width of the fastening strips at the beginning of the cuts 5-7 is larger than that in the region of the folding edges 8 or 9, or vice-versa. In any case, the selection of the length, the width and the direction of width of the fastening strips depends on the actual intended purpose of the attachment patch 1 according to the present invention.
FIG. 2 shows in perspective view a applied attachment patch 10 and a cannula 11 held by the fastening strips 3 and 4. These strips 3 and 4 are wound around the cannula 11 in a spiral helical direction in which each strip is wound oppositely to the other strip. The folding edges 8, 9 of patch 10 are moved near to the cannula 11 so that the cannula lies in the angle A formed by the folding edges 8, 9 of the lifted up fastening strips 3 and 4. Thus, it is possible to apply the fastening strips 3 and 4, which may be folded diagonally aside, to the cannula 11 without forming wrinkles. In particular, the cannula also forms the same angle A, preferably in the range of approximately 45° , to the adhesive area of the patch 10. The cannula 11 is thus safely and stably held by strips 3 and 4 and fixed into position.
FIG. 3 shows, in another embodiment, an oval attachment patch 12 prior to application to the skin of the person. The cuts 16, 17 and 18 forming the fastening strips 14, 15 extend substantially in the direction of the major axis or the longitudinal axis X of the oval. They do not run parallel to each other, but are directed in such a way that the distance between the outer cuts 16 and 18 forming the flap 13 gradually decreases from the beginning 30 to the end 32 thereof. The outer cuts 16 and 18 may also run parallel to each other or to the central cut 17, or they may run in opposite directions. It is also preferred, however, that the central cut 17 lies on the major axis X and extends beyond the outer cuts 16 and 18 so that folding edges 19 and 20 of cuts 16 and 18, respectively, are formed which run diagonally to the central cut. This is preferably effected in the manner described above. Angles B 3 and B 4 in FIG. 3 correspond, respectively, to angles B 1 and B 2 of FIG. 1.
It should be noted that the shape and dimension of the attachment patch 1 or 12 according to the present invention as well as the shape and dimension of the flap 2 or 13, respectively, may be adapted to the individual requirements in any desired manner. This assumes that the flaps 2 or 13, respectively, is divided by the two independent fastening strips 3 or 4 and 14 or 15, respectively, and that this relationship is maintained.
The present invention has the advantages that the handling of the attachment patch according to the present invention is particularly simple and safe and that it can be produced simply and at a reasonable price. The attachment patch according to the present invention provides a safe and stable fastening means for medical accessories of the kind mentioned hereinbefore.
While only two embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as defined in the appended claims. | An attachment patch for fastening medical accessories, such as cannulae, to the human skin, includes a carrier material provided with a pressure-sensitive adhesive layer, and a protective layer covering the pressure-sensitive adhesive layer and being provided with a lift-up type flap for fastening this cannula. The flap is divided into two fastening strips by a center cut, which preferably extends beyond the length of the flap. | 8 |
This is a continuation of application Ser. No. 08/318,976, filed Oct. 6, 1994, now abandoned which is a divisional of Ser. No. 07/982,092 Nov. 25, 1992 which has matured into U.S. Pat. No. 5,385,662 issued Jan. 31, 1995.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of producing oxide ceramic layers on barrier layer-forming metals or their alloys by plasma-chemical anodic oxidation in aqueous organic electrolytes, wherein the oxide ceramic layer may be further modified for specific applications. The present invention further relates to articles produced by the method.
2. Description of the Related Art
In aqueous electrolytes, the anodic oxidation described above is a gas/solid reaction under plasma conditions in which the high energy input at the base point of the discharge column produces liquid metal on the anode which forms with the activated oxygen a temporarily molten oxide. The layer formation is effected by partial anodes. The spark discharge is preceded by a forming process (P. Kurze; Dechema-Monographien Volume 121-VCH Verlagsgesellschaft 1990, pages 167-180 with additional literature references). The electrolytes are selected in such a way that their positive properties are combined and high-quality anodically produced oxide ceramic layers are formed on aluminum. By combining different salts, higher salt concentrations can be achieved in the electrolytic bath and, thus, higher viscosities can be achieved. Such high viscosity electrolytes have a high thermal capacity, they stabilize the oxygen film formed on the anode and, thus, they ensure a uniform oxide layer formation (DD-WP 142 360).
Because of the pattern of the current density/potential curves for the anodic spark discharge, the distinct portions can be distinguished, i.e. the Faraday portion, the spark discharge portion and the arc discharge portion, see P. Kurze mentioned above.
A barrier layer is naturally found on the metal or the metal alloy. By increasing the voltage of the anodically poled metal, the barrier layer increases. Consequently, a partial oxygen plasma which forms the oxide ceramic layer is created at the phase boundary metal/gas/electrolyte. The metal ion in the oxide ceramic layer is derived from the metal and the oxygen from the anodic reaction in the aqueous electrolyte. The oxide ceramic is liquid at the determined plasma temperatures of approximately 7,000° Kelvin. Toward the side of the metal, the time is sufficient for allowing the melted oxide ceramic to properly contract and, thus, form a sintered oxide ceramic layer which has few pores. Toward the side of the electrolyte, the melted oxide ceramic is quickly cooled by the electrolyte and the gases which are still flowing away, particularly oxygen and water vapor, leave an oxide ceramic layer having a wide-mesh linked capillary system. Pore diameters of 0.1 μm to 30 μm were determined by examinations using electron scan microscopes (Wirtz, G. P., et al., Materials and Manufacturing Processes, 1991, "Ceramic Coatings by Anodic Spark Deposition," 6(1):87-115, particularly FIGURE 12).
DE-A-2 902 162 describes a method in which spark discharge during the anodizing process is utilized for manufacturing porous layers on aluminum intended for use in chromatography.
EP-A-280 886 describes the use of the anodic oxidation with spark discharge on Al, Ti, Ta, Nb, Zr and their alloys for manufacturing decorative layers on these metals.
The above-described methods make it possible only to manufacture ceramic layers having relatively small thicknesses of up to a maximum of 30 μm which are insufficient for use as wear and corrosion protection layers.
SUMMARY OF THE INVENTION
Therefore, it is the object of the present invention to produce oxide ceramic layers on the above-mentioned metals which have a substantially greater layer thickness of up to 150 μm, are resistant to abrasion and corrosion and have a high alternating bending strength.
In accordance with the present invention, oxide ceramic layers are produced on aluminum, magnesium, titanium, tantalum, zirconium, niobium, hafnium, antimony, tungsten, molybdenum, vanadium, bismuth or their alloys by plasma-chemical anodic oxidation while maintaining the following parameters:
1. The electrolytic bath should be substantially free of chloride, which means that it contains less than 5×10 -3 mol/l chloride ions;
2. The electrolytic bath is adjusted to a pH value of 2 to 8;
3. The temperature of the bath is in the range of -30° to +15° C. and preferably between -10° and +15° C.;
4. The temperature of the bath is maintained constant within the limits of ±2° C.; and
5. The current density of at least 1 A/dm 2 is maintained constant until the voltage reaches an end value.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Within the scope of the present invention, aluminum and its alloys are very pure aluminum and, inter alia, the alloys AlMn; AlMnCu; AlMg1; AlMg1,5; E-AlMgSi; AlMgSi0,5; AlZnMgCu0,5; AlZnMgCu1,5: G-AlSi-12; G-AlSi5Mg; G-AlSi8Cu3; G-AlCu4Ti; G-AlCu4TiMg.
For the purposes of the invention, also suitable in addition to pure magnesium are the magnesium casting alloys with the ASTM designations AS41, AM60, AZ61, AZ63, AZ81, AZ91, AZ92, HK31, QE22, ZE41, ZH62, ZK51, ZK61 EZ33, HZ32 as well as the wrought alloys AZ31, AZ61, AZ 80, M1, ZK60, ZK40.
Moreover, pure titanium or also titanium alloys, such as, TiAl6V4; TiAl5Fe2,5, etc. can be used.
The chloride-free electrolytic bath may contain inorganic anions which are conventional in methods for the plasma-chemical anodic oxidation, namely, phosphate, borate, silicate, aluminate, fluoride or anions of norganic acids, such as, citrate, oxalate and acetate.
The electrolytic bath preferably contains phosphate ions, borate ions and fluoride ions in combination and in an amount of at least 0.1 mol/l of each individual of these anions up to a total of 2 mol/l.
The cations of the electrolytic bath are selected in such a way that they form together with the respective anions salts which are as soluble as possible in order to facilitate high salt concentrations and viscosities. This is usually the case in alkali-ions, ammonium, alkaline earth ions and aluminum ions up to 1 mol/l.
In addition, the electrolytic bath contains urea, hexamethylenediamine, hexamethylenetetarine, glycol or glycerin in an amount of up to a total of 1.5 mol/l as stabilizer.
For producing particularly wear-resistent oxide ceramic layers on aluminum or its alloys by plasma-chemical anodic oxidation at a current density of at least 5 A/dm 2 which is maintained constant until the voltage reaches an end value, it is possible to utilize even very significantly diluted electrolytic baths of the above-described composition in which the concentration of the anions is only 0.01 to 0.1 mol/l. In these significantly diluted baths, the pH value is between 10 and 12, preferably 11. Because of the low conductivity of this electrolytic bath, the voltage end value may reach up to 2000 V. The energy input caused by the plasma-chemical reaction is accordingly very high. The oxide ceramic layer formed on the aluminum materials consists of corundum, as was shown by X-ray diffraction examinations. A hardness of the oxide ceramic layer of up to 2000 HV is obtained. These oxide ceramic layers can be particularly used where an extremely high abrasive wear protection is required.
The selection of the type of voltage and current, such as, direct current, alternating current, 3-phase current, impulse current and/or interlinked multiple-phase current with frequencies of up to 500 Hz has surprisingly no influence on the process of forming ceramic layers on the metals.
The current supply to the plasma-chemical anodizing process for forming the ceramic layer is carried out in such a way that the required current density of at least 1 A/dm 2 is maintained constant and that the voltage is applied until a predetermined end value is reached. The voltage end value is between 50 and 400 volts and is determined by the metal used, i.e. by the alloy components of the metal, by the composition of the electrolytic bath and by the control of the bath.
As mentioned above, the invention also relates to articles produced by the above-described method, wherein the articles are of barrier layer-forming metals or their alloys with plasma-chemically produced oxide ceramic layers having a thickness of 40 to 150 μm, preferably 50 to 120,μm.
The following examples describe the present invention in more detail without limiting the scope of the invention.
EXAMPLE 1
A test plate of AlMgSi1 having a surface area of 2 dm 2 is degreased and subsequently washed with distilled water.
The test plate treated in this manner is plasmachemically anodically oxidized in an aqueous/organic chloride-free electrolytic bath having the following composition.
______________________________________(a) Cations 0.13 mol/l sodium ions 0.28 mol/l ammonium ions(b) Anions 0.214 mol/l phosphate 0.238 mol/l borate 0.314 mol/l fluoride(c) Stabilizer and complex forms 0.6 mol/l hexamethylenetetramine______________________________________
With a current density of 4 A/dm 2 and an electrolyte temperature of 12° C.±2° C. After a coating time of 60 minutes, the voltage end value of 250 volts is reached.
The test plate with ceramic layer is washed and dried. The thickness of the ceramic layer is 100 μm. The hardness of the ceramic layer is 750 (HV 0.015).
EXAMPLE 2
A dye cast housing of GD-AlSil2 having a surface area of 1 dm 2 is treated for one minute at room temperature in a pickle composed in equal halves of 40% HF and 65% HNO 3 and the housing is subsequently washed with distilled water.
The dye cast housing pickled in this manner is plasma-chemically anodically oxidized in the aqueous/organic chloride-free electrolytic bath of Example 1 at a current density of 8 A/dm 2 and an electrolyte temperature of 10° C.±2° C. After a coating time of 30 minutes, a voltage end value of 216 volts is registered.
The dye cast housing with ceramic layer is washed and dried.
The thickness of the ceramic layer is 40 μm.
EXAMPLE 3
A test plate of magnesium alloy of the type AZ 91 having a surface area of 1 dm 2 is pickled for 1 minute at room temperature in a 40% hydrofluoric acid.
The test plate treated in this manner is plasma-chemically anodically oxidized in an aqueous/organic chloride-free electrolytic bath of Example 1 at a current density of 4 A/dm 2 and an electrolyte temperature of 12° C.±2° C.
The voltage end value of 252 volts is reached after 17 minutes.
The ceramic layer has a thickness of 50 μm.
EXAMPLE 4
A rod of pure titanium having a length of 30 millimeters and a diameter of 5 millimeters is pickled in a pickle as in Example 2 and is subsequently washed with distilled water.
The rod treated in this manner is plasma-chemically anodically oxidized in an aqueous chloride-free electrolytic bath having the composition
______________________________________a) Cations 0.2 mol/l calcium ionsb) Anions 0.4 mol/l phosphate______________________________________
At a current density of 18 A/dm 2 and an electrolyte temperature of 10° C.±2° C.
After a coating time of 10 minutes the voltage end value of 210 volts is reached.
The rod with ceramic layer is washed with distilled water and is dried.
The thickness of the layer is 40 μm.
EXAMPLE 5
A gear wheel of AlMgSi1 having a surface area of 6 dm 2 is degreased and washed with distilled water. An electrolytic bath of Example 1 diluted 100 times with water is used as aqueous/organic chloride-free electrolytic bath which additionally contains 0.1 mol/l each of sodium aluminate and sodium silicate.
The gear wheel is plasma-chemically anodically oxidized at a current density of 10 A/dm 2 . After a coating time of 120 minutes, a voltage end value of 800 volts is reached.
The gear wheel with ceramic layer is washed and dried. The thickness of the oxide ceramic layer is 130 μm. The hardness of the ceramic layer is 1900 HV (0.1). The gear wheel coated in this manner has a service life which is 4 times that of a conventionally eloxated gear wheel having the same dimensions.
EXAMPLE 6
An ultrasonic sonotrode of AlZnMgCu1,5 having a surface area of 6.4 dm 2 is degreased and subsequently washed with distilled water.
The ultrasonic sonotrode treated in this manner is plasma-chemically anodically oxidized in an aqueous/organic chloride-free electrolytic bath, as described in Example 1, at a current density of 3.5 A/dm 2 and an electrolyte temperature of 15° C. After a coating time of 25 minutes, the voltage end value of 250 volts is reached.
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. | A method of producing oxide ceramic layers on Al, Mg, Ti, Ta, Zr, Nb, Hf, Sb, W, Mo, V, Bi or their alloys by a plasma-chemical anodical oxidation in a chloride-free electrolytic bath having a pH value of 2 to 8 and a constant bath temperature of -30° to +15° C. A current density of at least 1 A/dm 2 is maintained constant in the electrolytic bath until the voltage reaches a predetermined end value. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part application of patent application Ser. No. 09/961,052 filed on Sep. 24, 2001, which is a continuation application of patent application Ser. No. 09/319,176 filed on Jun. 3, 1999, now U.S. Pat. No. 6,355,260 issued on Mar. 12, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to a method of manufacturing pigments having a surface coated with a particular inorganic compound, and more specifically to a method of manufacturing white or colored pigments with improved capability for preventing change of color caused when wet with water or oil and degradation in hiding performances thereof. Furthermore, the present invention relates to a method of manufacturing cosmetics with the white or colored pigment blended therein.
BACKGROUND TECHNOLOGY
[0003] White pigments such as titanium oxide or zinc oxide and inorganic colored pigments such as Indian red, yellow iron oxide, black iron oxide, and ultramarine blue pigment, or organic pigments such as tar coloring matter generally change the colors to darker ones when wet with water or oil with the hiding performances degraded. This phenomenon occurs because a light reflectance or a scattering effect of the surface of pigments becomes lower.
[0004] By mixing the white or colored pigment as described above in cosmetics used for making-up, there are provided effects such as those of covering defects of human skin such as wrinkles or masculae or a coloring effect to make human skin look more attractive. However, as time goes by after the cosmetic is applied to human skin and a surface of pigments blended therein is wet with skin fats or sweat, a reflectance or scattering capability of the pigments becomes smaller with a color tone of the cosmetic film changing and also with the masking capability becoming lower, so that the capability of the cosmetics to cover human skin degrades.
[0005] There has been used a method of giving water repellency or oil repellency to pigments by treating with silicon-based or fluorine-based compounds to improve a stability in use for a long time of cosmetics. With this kind of cosmetics, the cosmetic effect can be preserved for a longer period of time to some extent by making it harder to be wet with skin fat or sweat, but the adequate stability in use for a long time has not be realized.
[0006] Further there is a method of preventing or delaying a pigment from getting wet by simultaneously mixing porous silica or the like in cosmetics so that skin fats or sweat secreted in association with passage of time is absorbed in the silica or the like, but the effect is not adequate at present.
[0007] Further in some of the cosmetics with the white or colored pigments blended therein, sometimes oil and fat, moistener, a surfactant, an organic thickener, an organic solvent or the like blended in cosmetics may be oxidized or decomposed, which in turn degrades the appearance or performance. Also in cosmetics with certain types of colored pigments blended therein, active oxygen is generated, and this active oxygen may promote aging of human skin onto which the cosmetics is applied.
DISCLOSURE OF THE INVENTION
[0008] It is an object of the present invention to provide white or colored pigments, which do not suffer from color tone or hiding performances thereof even when the surface is moistened with water or oil, without spoiling coloring performance or hiding performance of the pigments themselves.
[0009] Further it is another object of the present invention to provide cosmetics which can preserve the excellent effect for a long period of time and does not change the color tone by oxidizing or decomposing organic compounds blended therein nor lower its appearance and performances.
[0010] In the pigments according to the present invention, surfaces of the pigments are covered with an inorganic compound having the refractive index of 1.8 or below.
[0011] The inorganic compound is preferably silicon oxide. The pigments are preferably inorganic pigments comprising titanium oxide, zinc oxide, or iron oxide.
[0012] In the cosmetics according to the present invention, the pigments are blended therein.
BRIEF DESCRIPTION OF THE INVENTION
[0013] [0013]FIG. 1 is a graph showing a change in the reflectance when white pigments (W, Ws) are moistened with CTG;
[0014] [0014]FIG. 2 is a graph showing a color difference of the white pigments (W, Ws) when the pigments are moistened with CTG;
[0015] [0015]FIG. 3 is a graph showing a color difference of the white pigments (W, Ws) when the pigments are moistened with water;
[0016] [0016]FIG. 4 is a graph showing a change in the reflectance when red pigments (R, Rs) are moistened with CTG;
[0017] [0017]FIG. 5 is a graph showing a color difference of the red pigments (R, Rs) when the pigments are moistened with CTG;
[0018] [0018]FIG. 6 is a graph showing a color difference of the red pigments (R, Rs) when the pigments are moistened with water;
[0019] [0019]FIG. 7 is a graph showing a change in the reflectance when the yellow pigments (Y, Ys) are moistened with CTG;
[0020] [0020]FIG. 8 is a graph showing a color difference of the yellow pigments (Y, Ys) when the pigments are moistened with CTG;
[0021] [0021]FIG. 9 is a graph showing a color difference of the yellow pigments (Y, Ys) when the yellow pigments are moistened with water;
[0022] [0022]FIG. 10 is a graph showing a color difference of the white pigments (Ws 2 ) when the pigments are moistened with CTG;
[0023] [0023]FIG. 11 is a graph showing a color difference of the white pigments (Ws 2 ) when the pigments are moistened with water;
[0024] [0024]FIG. 12 is a graph showing a color difference of the red pigments (Rs 2 ) when the pigments are moistened with CTG;
[0025] [0025]FIG. 13 is a graph showing a color difference of the red pigments (RS 2 ) when the pigments are moistened with water;
[0026] [0026]FIG. 14 is a graph showing a color difference of the yellow pigments (Ys 2 ) when the pigments are moistened with CTG; and
[0027] [0027]FIG. 15 is a graph showing a color difference of the yellow pigments (Ys 2 ) when the pigments are moistened with water.
BEST MODE FOR CARRYING OUT THE INVENTION
[0028] Detailed description is made hereinafter for preferable embodiments of the present invention.
[0029] Generally, a reflectance and a scattering coefficient of substance are decided by a difference and a ratio between the refractive index of the substance and that of medium present around the substance, and when the difference and the ratio become smaller, the reflectance and the scattering coefficient become lower.
[0030] The expression (1) below is that developed by Fresnel for a reflectance R of a substance. The expression (2) is that for calculating a light scattering coefficient S in which the expression developed by Rayleigh for a scattering coefficient of light is applied:
R=[(n p −n b )/(n p +n b )] 2 (1)
[0031] wherein n p is a refractive index of particles, and n b is a refractive index of medium.
S=α[(m 2 −1)/(m 2 +1)] 2 (2)
[0032] wherein m is n p /n b and a is a coefficient.
[0033] For the reasons as described above, reflectances R and scattering coefficients S of titanium oxide as white pigments (with the refractive index of 2.72), Indian red (with the refractive index of 2.78), yellow iron oxide (with the refractive index of 2.00) or the like are generally decided by a difference and a ratio between a refractive index of each of the substances and that of air as a medium.
[0034] When a surface of the pigment is moistened, for instance, with water, the medium changes from air with the refractive index of 1.00 to water with the refractive index of 1.33, so that the reflectance R and the scattering coefficient S before moistened with water are different from those after moistened with water.
[0035] On the other hand, a refractive index of silica which is an inorganic compound is 1.47, and as the refractive index is smaller than that of the pigments described above, the difference and the ratio between the refractive index of the substance before moistened with water and that after moistened with water is smaller as compared to that of the pigments. Namely a change in the reflectance R and the scattering coefficient S is smaller.
[0036] An object of the present invention is to provide pigments which suppress the change of the reflectance and the scattering coefficient even when moistened with, for instance, water by covering a surface of the white or colored pigment generally having a large refractive index with a substance having a low refractive index which is close to that of water or oil.
[0037] Ordinary inorganic pigments or organic pigments are used in the present invention. The inorganic pigments, which can be used according to the present invention, include such as titanium oxide, zinc oxide, zirconium oxide, cerium oxide, Indian red, yellow iron oxide, black iron oxide, ultramarine blue, dark blue, barium sulfate, titanated mica, mica, sericite, talc, bentonite, kaolin, and mixed pigments having a color of human skin comprising titanium oxide and iron oxide. Organic pigments available according to the present invention include Red No. 202 (lithol rubine BCA), Red No. 203 (lake red C), Red No. 204 (lake red CBA), Red No. 205 (lithol red), Red No. 207 (lithol red BA), Orange No. 203 (permanent orange), Orange No. 204 (benzidine orange G), Yellow No. 205 (benzidine yellow G), Blue No. 201 (indigo), Blue No. 204 (carbanthrene blue).
[0038] These pigments are generally white or colored particles, and the average diameter of the particles is preferably in a range from 0.1 to 1 μm. There is no specific limitation concerning a form of the particles, and the particles may have any forms including a sphere, a rod, a needle, a plate and a flake.
[0039] As an inorganic compound having a low refractive index used for covering a surface of the pigment particle, an inorganic oxide having a refractive index in a range from 1.8 to 1.2, and preferably in range from 1.7 to 1.4 should be used, and the inorganic compounds include silica (with the refractive index of 1.47), alumina (with the refractive index of 1.7), and phosphorus oxide (with the refractive index of 1.7).
[0040] As for a method of covering the surfaces of pigment particles with the inorganic compounds as described above, there is no specific limitation on the condition that the inorganic compounds can homogeneously be spread over the surfaces of the pigment particles. For instance, there can be enumerated the method in which a silica coating film is formed by adding a silicic acid solution in a dispersion of the pigment particles for having the silicic acid polymer deposited on the surfaces of the pigment particles. Also the method can be used in which a hydrolytic organic silicon compound such as tetraethoxysilane is added in a dispersion of the pigment particles so that the organic silicon compound is hydrolyzed to form a silica coating film on the surfaces of the pigment particles.
[0041] Generally, it is relatively difficult to obtain the silicic acid solution, since silicic acid has very low solubility in water. The silicic acid shows relatively good solubility only in hot water above 100° C. For example, SiO 2 is soluble about 0.005% in hot water at about 200° C. In a weak alkaline solution, the solubility is increased. The silicic acid solution can be obtained by removing alkaline form silicic acid alkaline aqueous solution with an ion-exchange resin. The solution is stable at a room temperature until the concentration of SiO 2 becomes 5 to 6 wt. %.
[0042] The silicic acid solution has preferably a concentration in a range of 0.1 to 7.0 wt. %, more preferably in a range of 0.5 to 6.0 wt. %. When the silicic acid solution has a concentration below 0.1 wt. %, productivity and yield tend to be low. It is difficult to obtain the silicic solution with a concentration above 7.0 wt. %. When the silicic acid solution with a concentration above 7.0 wt. % is used, the resultant white pigments may be agglomerated.
[0043] The silicic acid solution to be used has preferably pH in a range of 0.1 to 3.5, more preferably in a range of 0.5 to 3.2.
[0044] When the silicic acid solution has pH below 0.1, the acidity is too strong to use for a certain type of pigment. When the silicic acid solution has pH above 3.5, the solution becomes unstable and it is difficult to form the coating.
[0045] When the silicic acid solution is used for coating, the solution is heated at a temperature below 100° C., preferably below 90° C. The silicic acid solution was stable at a room temperature, however, the solution became in a gel state when heated. When the silicic acid solution is used for coating, since silica in the silicic acid solution is deposited on the surfaces of the particles, the concentration of silica in the solution decreases. Accordingly, in the coating process, it is possible to heat the silicic acid solution up to 80 to 100° C.
[0046] On the other hand, an alumina coating film can be formed on the surfaces of pigment particles by adding an organic aluminum compound such as aluminum tetraalkoxide in a dispersion of pigment particles for hydrolysis or by adding a sulfate, a hydrochloride, a nitrate, or organic salts of aluminum.
[0047] A relative quantity of an inorganic compound used for coating against 100 weight parts of pigments is in a range from 1 to 40 weight parts, and preferably in a range from 5 to 30 weight parts. If the rate is less than one weight part, the effect can not be expected, and when the rate is more than 40 weight parts, the hiding performances become lower, or the coloring capability becomes lower.
[0048] Next, description is made for the cosmetics according to the present invention. The cosmetics according to the present invention contain the pigments according to the present invention as described above, but the cosmetics never oxidize nor decompose an organic compound blended therein such as oil with a volume of active oxygen generated rather small, and in addition direct contact of the pigments with human skin is suppressed, so that aging of skin can be prevented. Further a color tone of the cosmetics does not change with the appearance and performances not being lowered.
[0049] A blending rate of the pigments in the cosmetics according to the present invention is preferably in a range from 1 to 80 wt. %. When the rate is less than 1 wt. %, the blending effect is not obtained at all, and if the rate surpasses 80 wt. %, the hiding performances become too strong, which hinders the natural effect provided by the cosmetics.
[0050] It should be noted that, when the coated pigments according to the present invention are blended in cosmetics, the surfaces of the pigments may be treated with a silicone or a fluorine compound.
[0051] The cosmetics according to the present invention contain various types of components blended in the ordinary cosmetics, 0.5 namely at least one or more of higher aliphatic alcohols; higher fatty acids; oils such as ester oil, paraffin oil, and wax; alcohols such as ethyl alcohol, propylene glycol, sorbitol, and glycerin; moistners such as mucopolysaccharide, collagens, PCA salts, lactate; various types of surfactants such as nonion-based, cation-based, anion-based, or amphoric surfactants; thickeners such as gum arabic, xanthan gum, polyvinylpyrrolidone, ethyl cellulose, carboxymethyl cellulose, carboxyvinyl polymer, denatured or not-denatured clay minerals; solvents such as ethyl acetate, acetone, toluene; inorganic pigments/dyes; organic pigments/dyes; antioxydants such as BHT, tocopherol; water; drugs; ultraviolet absorbent; pH buffers; chelating agents; preservatives; and perfumes. Also at least one or more of inorganic fillers such as silica, talc, kaolin, mica; extender pigments, and various types of organic resin may be contained therein.
[0052] The cosmetics according to the present invention may be manufactured by using any conventional technology, and is used in various forms including powder, cake, pencil, stick, liquid, and cream, and more specifically foundations, cream, emulsions, eye-shadow, base for cosmetics, nail enamel, eye liner, mascara, lipsticks, pack, cosmetic water, shampoo, rinse, hair colors are included in the cosmetics according to the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0053] Detailed description is made hereinafter for embodiments of the present invention, and the embodiments are provided only for explaining the present invention. As pigments for the present invention, inorganic compounds other than those used in the embodiments described below, such as alumina or phosphorus oxide may be used. So the present invention is not limited to the embodiments described below. A scope of the present invention is defined by the claims, and is not restricted by descriptions in the specification. Variants and modifications within equivalent scopes of the claims are within a scope of the present invention.
[0054] Embodiment 1
[0055] 90 g of white pigments (W) made of titanium oxide and having an average particle diameter of 250 nm were mixed in one litter of ethanol to prepare a dispersion. This dispersion was heated to 45° C. and 28% aqueous ammonia was added to adjust pH to 9.5 or more, and then 10 g of tetraethoxysilane as SiO 2 and 110 g of 28% aqueous ammonia were added to the dispersion while preserving the conditions described above. After addition of the compounds described above, the dispersion was further agitated for additional two hours, and then filtered, washed, and dried under the temperature of 110° C., and further sintered under the temperature of 600° C., and silica-coated titanium oxide white pigments (Ws) were obtained. The white pigments were observed with an electronic microscope, and it was found that the particles were not aggregated and the particle shapes and diameters before and after coating with silica were substantially identical.
[0056] Change of a color tone when the resultant silica-coated white pigments were moistened with water and oil was assessed in the following way. At first, the silica-coated white pigments (Ws) and titanium oxide white pigments non-coated with silica (W) were mixed with caprylic triglyceride (sometimes described as CTG hereinafter), which is a main component of sebum, at the pigments vs. CTG ratio of 84/16 (weight ratio) to prepare pigment samples (Ws-c) and (W-c) moistened with CTG respectively. Reflectances of these samples were measured with a calorimeter (manufactured by Minolta, CM-2002), and a result of measurement is shown in FIG. 1. In a case where a mixing ratio of pigments vs. CTG was changed, changes in a color difference (ΔE) between colors when CTG was mixed in silica-coated white pigments (Ws-c) as well as in titanium oxide white pigments non-coated with silica (W-c) and those when CTG was not mixed therein were measured with the same calorimeter and a result of measurement is shown in FIG. 2.
[0057] Next, when pigments and water were mixed and the mixing ratio was changed, changes in color differences (ΔE) of white pigments coated with silica (Ws-w) and of white pigments non-coated with silica (W-w) were measured similarly, and a result of the measurement is shown in FIG. 3.
[0058] Measured values for color differences (ΔE) in samples when the mixing ratio of pigments/CTG was 84/16 (weight ratio) and when the mixing ratio of pigments/water was 84/16 (weight ratio) and decrease rate (%) in color differences of the white pigments coated with silica against white pigments non-coated with silica (Ws) are shown in Table 1.
[0059] It should be noted that the term of color difference (ΔE) as defined herein quantitatively shows visually different colors and is obtained by using Hunter's color difference formula as defined in 6.3.2 of JIS Z 8730 (Method for Specification Color Difference) which is incorporated herein together with JIS Z 8722 referred to by JIS Z 8730. The color difference formula is as shown below:
Δ E =[(Δ L ) 2 +(Δ a ) 2 +(Δ b ) 2 ] 1/2
[0060] wherein ΔL, Δa and Δb are differences of brightness index L, and chromaticness indexes a and b between two surface colors in Hunter's color difference formula.
TABLE 1 Color difference (ΔE) CTG 16 wt. % Water 16 wt. % Non-coated white pigments (W): 4.5 8.8 Silica-coated white pigments (Ws): 0.73 0.95 Decrease rate (%) of ΔE: 84 89
[0061] In FIG. 1, before CTG was mixed, a spectral reflectance of the white pigments coated with silica (Ws) is substantially not different from that of the white pigments non-coated with silica (W), but after CTG was mixed therein, comparison of the spectral reflectance shows that a decrease rate in the white pigments coated with silica (Ws) is smaller.
[0062] Also it can be observed that, for the color difference (ΔE), change in the white pigments coated with silica (Ws-C), (Ws-w) is smaller, which clearly indicates that change in a color tone of the white pigments coated with silica was suppressed.
[0063] Embodiment 2
[0064] Indian red pigments coated with silica (Rs) was obtained by the same method as that described above excluding only the point that Indian red pigments (R) made from needle-shaped particles each having an average length of 500 nm and an average diameter of 100 nm was used in place of the titanium oxide used in Embodiment 1. Observation of the red pigments with an electronic microscope showed that the particles were not aggregated and particles shapes and diameters before and after coating with silica were substantially identical.
[0065] Changes of a color tone for the resultant red pigments coated with silica (Rs) and red pigments non-coated with silica (R) were measured like in Embodiment 1. A result of the measurement is shown in FIG. 4 to FIG. 6 and in Table 2.
TABLE 2 Color difference (ΔE) CTG 16 wt. % Water 16 wt. % Non-coated red pigments (R): 11 11 Silica-coated red pigments (Rs): 4.9 3.3 Decrease rate (%) of ΔE: 55 70
[0066] Like in a case of the titanium oxide white pigments, change in a color tone of the red pigments coated with silica (Rs-c), (Rs-w) is smaller as compared to that of the red pigments non-coated with silica (R-c), (R-w) even when moistened with CTG and water.
[0067] Embodiment 3
[0068] Yellow iron oxide pigments coated with silica (Ys) was obtained by the same method as that described above excluding only the point that yellow iron oxide pigments (Y) made from needle-shaped particles each having an average length of 500 nm and an average diameter of 100 nm was used in place of the titanium oxide used in Embodiment 1. Observation of the yellow pigments with an electronic microscope showed that the particles were not aggregated and particles shapes and diameters before and after coating with silica were substantially identical.
[0069] Changes in a color tone of the resultant yellow pigments coated with silica (Ys) and yellow pigments non-coated with silica (Y) were measured like in Embodiment 1. A result of the measurement is shown in FIG. 7 to FIG. 9 and in Table 3.
TABLE 3 Color difference (ΔE) CTG 16 wt. % Water 16 wt. % Non-coated yellow pigments (Y): 17 15 Silica-coated yellow pigments (Ys): 4.1 4.4 Decrease rate (%) of ΔE: 76 71
[0070] It is understood from the table above that, like in a case of the titanium oxide white pigments, change in a color tone of the yellow pigments coated with silica (Ys-c), (Ys-w) is smaller as compared to that of the yellow pigments non-coated with silica (Y-c), (Y-w) even when moistened with CTG or water.
[0071] Embodiment 4
[0072] The foundation containing the following ingredients was prepared:
Wt. % (1) White pigments coated with silica (Ws) 10.7 (2) Red pigments coated with silica (Rs) 0.55 (3) Yellow pigments coated with silica (Ys) 2.5 (4) Black iron oxide 0.15 (5) Talc 20 (6) Synthesized mica 36.9 (7) Sericite 17 (8) Silica beads 4.2 (9) Silicone oil 3 (10) Squalane 3.2 (11) Ester oil 1.6 (12) Solbitane sesquiorate 0.2 (13) Perfume As required (14) Ethylparaben As required
[0073] At first, a mixture of the ingredients (1) to (8) was prepared. The ingredients (1) to (3) were pigments obtained in Embodiments 1 to 3. Then the ingredients (9) to (14) were fully mixed under a temperature of 70° C., and the mixture was added into the mixture of the ingredients (1) to (8), and the two mixtures were mixed to obtain a homogeneous mixture. The resultant mixture was dried, pulverized to particles each having a homogeneous size, and compressed for molding.
[0074] The resultant foundation was applied to faces of woman panelers, and the cosmetic effect in 3 hours was assessed. It was observed that the hiding performances became slightly lower in the so-called T zone comprising a brow and a bridge of a nose where sebum is much secreted, but that in other portions of the face the cosmetic effect immediately after the application thereof was preserved as it was.
[0075] Comparative Embodiment 1
[0076] In Embodiment 4, a powder foundation was prepared by the same method excluding only the point that the white (W), red (R), and yellow (Y) pigments non-coated with silica used in Embodiment 1 to 3 above were blended in place of the white (Ws), red (Rs), and yellow (Ys) pigments coated with silica respectively. This foundation was assessed in the same way as that described above, and it was observed that the color tone was changed to a thin brown color on the entire face, especially in the T zone or an area close to a cheek with the hiding performances substantially lowered and that the excellent cosmetic effect could not be obtained.
[0077] Embodiment 5
[0078] 90 g of the titanium oxide white pigments (W) same as that used in Embodiment 1 was suspended in water so that the concentration was 10 wt. %, and the suspension was heated to 80° C., then 10 wt. % aluminum sulfate solution with the weight equivalent to 10 g of Al 2 O 3 was added to the suspension over four hours while maintaining the pH at around 6 by adding a sodium hydroxide solution. The suspended particles were coated by alumina hydrate deposited on the surfaces of the suspended particles.
[0079] Then the suspended particles were filtered, washed, and dried under a temperature of 110° C., and sintered under 600° C., and titanium oxide white pigments coated with alumina (Wa) were obtained. These white pigments were observed with an electronic microscope, and it was observed that the particles were not aggregated and a form and a size of the particles were changed from those before coating with alumina.
[0080] Change in a color tone of the resultant white pigments coated with alumina (Wa) when moistened with oil and water was measured and assessed like in Embodiment 1. Color differences (ΔE) when the mixing ratio of pigments vs. CTG was 84/16 (weight ratio) and when the mixing ratio pigments vs. water was 84/16 (weight ratio) are shown in Table 4, and the result was almost the same as that obtained for the white pigments coated with silica (Ws).
TABLE 4 Color difference (ΔE) CTG 16 wt. % Water 16 wt. % Non-coated white pigments (W): 4.5 8.8 Alumina-coated white pigments (Wa): 1 1 Decrease rate (%) of ΔE: 78 89
[0081] Embodiment 6
[0082] Black iron oxide pigments coated with silica (Bs) were obtained by the same method excluding only the point that black iron oxide (B) made from needle-shaped particles each having an average length of 500 nm and an average diameter of 100 nm was used in place of the titanium oxide in Embodiment 1. These black pigments were observed with an electronic microscope, and it was found that a form and a size of the particles were substantially identical to those before coating with silica.
[0083] Then 10 g of the black iron oxide pigments coated with silica (Bs), and 10 g of black iron oxide (B) without coating were added in three vessels V 1 , V 2 and V 3 each containing 100 g of soybean oil respectively. The samples were agitated under 98° C. and air was supplied into each vessel at a rate of 2.33 milli-liter/sec over six hours. Then the samples were cooled, the soybean oil with pigments added therein was filtered, and a peroxide value of each soybean oil sample was measured for assessing a degree of oxidation.
[0084] The peroxide value was measured by mixing soybean oil in a solvent prepared by mixing chloroform and acetic acid at a volume ratio of 2:3 and by iodometry. A result of the measurement is shown in Table 5, and it is understood from Table 5 that the black iron oxide pigments coated with silica (Bs) were substantially inert to soybean oil and had the capability of suppressing decomposition of the organic compounds such as oily components.
TABLE 5 Peroxide value Vessel Type of soybean oil (milli-equivalent/kg) — Unprocessed soybean oil 4.3 V 1 Bs added soybean oil 19.6 V 2 B added soybean oil 173.2 V 3 Nothing added soybean oil 18.2
[0085] Embodiment 7
[0086] An experiment for generation of active oxygen was carried out for the pigments coated with an inorganic compound according to the present invention. Aging due to active oxygen can not directly be examined on human skin, so that the indirect method as described below was carried out. Namely, it is generally known that generation of acetone from isopropyl alcohol is performed through the oxidation reaction indicated by the following model equation (3):
(CH 3 ) 2 ·CH·OH+(O)→(CH 3 ) 2 ·CO+H 2 O (3)
[0087] 50 g of isopropyl alcohol was put in each of two glass vessels V 4 , V 5 with 10 g of the titanium oxide white pigments coated with silica (Ws) obtained in Embodiment 1 added in the vessel V 4 and 10 g of thee titanium oxide white pigments (W) used in Embodiment 1 added in the vessel V 5 , then air in each vessel was replaced with nitrogen gas, each vessel was shielded and exposed to sun light for one month. Then acetone in isopropyl alcohol with pigments having been removed therefrom was analyzed by means of the gas chromatography. Acetone was detected in isopropyl alcohol with the titanium oxide white pigments (W) added therein, but was not detected in isopropyl alcohol with the titanium oxide white pigments coated with silica (Ws) added therein.
[0088] Further generation of active oxygen was checked for the titanium oxide white pigments coated with silica (Ws) and titanium oxide white pigments (W) respectively with an electronic spin resonance device (manufactured by Nippon Denshi: JES-TE200). 50 μg of the pigments, 200μ liter of ultra-pure deionized water, and 3μ liter of spin trap agent (DMPO) were put in a glass test tube, supernatant was recovered in around 30 seconds and measured. Signals caused by active oxygen were observed in all samples, and it was observed that a peak due to active oxygen and a volume of generated active oxygen in the titanium oxide white pigments coated with silica (Ws) were smaller as compared to those in the titanium oxide white pigments (W).
[0089] Embodiment 8
[0090] Ion-exchanged water was added to an aqueous solution of sodium silicic acid in which a concentration of SiO 2 was 24.0 wt. % and a molar ratio of SiO 2 /Na 2 O was 3:1 to obtain an aqueous solution of sodium silicic acid in which a concentration of SiO 2 was 5.2 wt. %. A hydrogen-type positive ion-exchange resin (Diaion SK-1B, product of Mistubishi Chemical Co. Ltd.) was added to the aqueous solution for ion-exchange, and a silicic acid solution was obtained in which a concentration of SiO 2 was 5.0 wt. % and pH was 2.7.
[0091] 200 g of the titanium oxide white pigments (W) same as that used in Embodiment 1 was mixed in 1.8 liter of water, and the mixture was heated to a temperature of 80° C. Then, 15 wt. % ammonia solution was added to prepare the mixture at pH 9.5, and while this condition was maintained, 444.0 g of the silicic acid solution obtained in the step described above was added over 8 hours. During the addition of the silicic acid solution, 15 wt. % ammonia solution was added to maintain the mixture at pH 9.5. Upon completion of the addition, the mixture was stirred for 2 hours and cooled.
[0092] Then, the suspended particles were filtered, washed, and dried at 110° C., and sintered under 600° C. to obtain titanium oxide white pigments coated with silica (Ws 2 ). The white pigments were observed with an electronic microscope, and it was observed that the particles were not aggregated and a form and a size of the particles were not changed from those before coating with silica.
[0093] Change in a color tone of the resultant white pigments coated with silica (Ws 2 ) when moistened with oil and water was measured and assessed similar to Embodiment 1. When a mixing ratio of the pigments and CTG was 84/16 (weight ratio), reflectance was almost the same as that of the pigments coated with silica (Ws-c) obtained in Embodiment 1. A change in the color difference (ΔE) at a different mixing ratio of the pigments and CTG is shown in FIG. 10.
[0094] Next, the pigments were mixed with water at a different mixing ratio, and a change in the color difference (ΔE) of the pigments coated with silica (Ws 2 ) is shown in FIG. 11. The pigments coated with silica (Ws 2 ) show the change in the color difference (ΔE) when moistened with oil and water substantially same as that of the pigments coated with silica (Ws) obtained in Embodiment 1, and smaller than that of the titanium oxide without silica coating (W).
[0095] Changes in a color tone of the resultant white pigments coated with silica (Ws 2 ) and the white pigments without coating (W) when moistened with oil and water were measured and assessed. Color differences (ΔE) when the mixing ratio of pigments vs. CTG was 84/16 (weight ratio) and when the mixing ratio pigments vs. water was 84/16 (weight ratio) are shown in Table 6, and decrease rates (%) of the white pigments coated with silica relative to the white pigments without coating are shown.
TABLE 6 Color difference (ΔE) CTG 16 wt. % Water 16 wt. % Non-coated white pigments (W): 4.5 8.8 Silica-coated white pigments (Ws 2 ): 0.8 1.0 Decrease rate (%) of ΔE: 82 89
[0096] Embodiment 9
[0097] Indian red pigments coated with silica (Rs 2 ) was obtained by the method same as that in Embodiment 8 except that the Indian red pigments (R) used in Embodiment 2 was used in place of the titanium oxide used in Embodiment 1. Observation of the red pigments with an electronic microscope showed that the particles were not aggregated, and shapes and diameters of the particles before and after the coating with silica were substantially identical.
[0098] A change in a color tone for the red pigments coated with silica (Rs 2 ) was measured similar to Embodiment 1. A result of the measurement is shown in Table 7 and FIGS. 12 and 13. When a mixing ratio of the pigments and CTG was 84/16 (weight ratio), reflectance was almost the same as that of the Indian red pigments coated with silica (Rs) obtained in Embodiment 2. The red pigments coated with silica (Rs 2 ) show the change in the color difference smaller than that of the red pigments without silica coating, similar to the red pigments coated with silica (Rs) obtained in Embodiment 2.
TABLE 7 Color difference (ΔE) CTG 16 wt. % Water 16 wt. % Non-coated red pigments (R): 11 11 Silica-coated red pigments (Rs 2 ): 3.8 3.7 Decrease rate (%) of ΔE: 65 66
[0099] Embodiment 10
[0100] Yellow iron oxide pigments coated with silica (YS 2 ) was obtained by the method same as that in Embodiment 8 except that the yellow iron oxide pigments (Y) used in Embodiment 3 was used in place of the titanium oxide used in Embodiment 1, and the pigments were not sintered at 600° C. Observation of the yellow pigments with an electronic microscope showed that the particles were not aggregated, and shapes and diameters of the particles before and after coating with silica were substantially identical.
[0101] Similar to Embodiment 1, a change in a color tone of the yellow pigments coated with silica (Ys 2 ) was measured. A result of the measurement is shown in Table 8 and FIGS. 14 and 15. When a mixing ratio of the pigments and CTG was 84/16 (weight ratio), reflectance was almost the same as that of the yellow pigments coated with silica (Ys) obtained in Embodiment 3. The yellow pigments coated with silica (Ys 2 ) show the change in the color difference smaller than that of the yellow pigments without silica coating, similar to the yellow pigments coated with silica (Rs) obtained in Embodiment 3.
TABLE 8 Color difference (ΔE) CTG 16 wt. % Water 16 wt. % Non-coated yellow pigments (Y): 17 15 Silica-coated yellow pigments (Ys 2 ): 4.8 4.5 Decrease rate (%) of ΔE: 72 70
[0102] Embodiment 11
[0103] Black iron oxide pigments coated with silica (Bs 2 ) were obtained by the method same as that in Embodiment 8 except that the black iron oxide (B) used in Embodiment 6 was used in place of the titanium oxide used in Embodiment 1 and the pigments were not sintered at 600° C. The black pigments were observed with an electronic microscope, and it was found that shapes and sizes of the particles were substantially identical to those before coating with silica.
[0104] Then, similar to Embodiment 6, activity of the black iron oxide pigments coated with silica (Bs 2 ) relative to the soybean oil was evaluated. A peroxide value of the soybean oil containing the black iron oxide pigments coated with silica (Bs 2 ) was 19.3 (milli-equivalent/kg) substantially same as that of the black iron oxide pigments coated with silica (Bs) obtained in Embodiment 6. Accordingly, it is found that the black iron oxide pigments coated with silica (Bs 2 ) has the capability of suppressing decomposition of an organic compound such as an oily component.
[0105] Embodiment 12
[0106] A powder foundation was prepared by the method same as that in Embodiment 4 except that the white (Ws 2 ), red (Rs 2 ), and yellow (YS 2 ) pigments coated with silica were used in place of the white (Ws), red (Rs), and yellow (Ys) pigments coated with silica. The foundation was assessed in the way same as that in Embodiment 4 using the women panelers. It was observed that the hiding performances became slightly lower in the so-called T zone comprising a brow and a bridge of a nose, and in other portions of the faces the cosmetic effect immediately after the application thereof was preserved as it was.
[0107] While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims. | In a method of manufacturing pigments, a dispersion of pigment particles is prepared, to which a silicic acid solution is added to have silicic acid polymer deposited on the surfaces of the pigment particles. The surfaces of the pigment particles are coated homogeneously with the silicic acid polymer having refractive index of at most 1.8 to thereby reduce a change of color of the pigment particles coated with the silicic acid polymer when caprylic triglyceride or water is added. The cosmetics are blended with the pigments therein. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to an electric apparatus for interfacing between two controls sections, particularly to an electronic apparatus characterized by a power saving mode.
BACKGROUND OF THE INVENTION
[0002] In such an apparatus as a multifunction device provided with a facsimile function, an overall control section for overall control of the operations of the entire system is configured independently of a communications control section for controlling the facsimile communications. The functions and loads are controlled separately between them through exchange of required information between these control 2 6541 sections, thereby meeting the requirements for a high degree of functionality and high speed.
[0003] When the control sections are separately configured, as described above, a variety of parameters required for the control of overall operation are usually stored in the nonvolatile memory of the overall control section, and are placed under collective management. The parameters for communications control are transferred from the overall control section to the communications control section.
[0004] To minimize power consumption, many of the electronic systems used on the wait mode for a long time such as a facsimile machine are provided with a power-saving mode. To maximize the power-saving effect, the various portions of the apparatus is turned off, except for the circuit that monitors the causes for returning, including user operations and incoming signals.
[0005] When the control section is divided into two sections: overall control section and communications control section, there are differences in initialization times after power has been turned on, and the overall control section handling a great amount of throughput starts up later than the communications control section. Thus, when power supply has turned on from the power-saving mode due to incoming signals, even if the communications control section has started, the parameters for communications control cannot be received from the overall control section if the overall control section has not yet started. A response to incoming signals cannot be made until the overall control section starts up, according to the prior art.
[0006] To solve this problem, an electronic apparatus (e.g. Official Gazette of Japanese Patent Tokkai 2003-32400) has been proposed, wherein the data such as communications control parameters to be transferred from a first controller (e.g. overall control section) to a second controller (e.g. communications control section) is stored into nonvolatile storage section that cannot be accessed by the second control section. When power has been turned on, the return mode is evaluated. If power supply has turned on from power-saving mode, data is sent to the RAM (Random Access Memory) of the second control section from the nonvolatile storage section, instead from the first control section.
[0007] In the prior art described in the in the Patent Document 1, when power has been turned on, evaluation is made to see if power supply has turned on from power-saving mode. After that, a data transfer method must be selected. This arrangement involves complicated processing after power turns on.
[0008] Further, the data has to be transferred from the nonvolatile storage section to the RAM of the second control section. Accordingly, data transfer is permitted only after termination of the initialization in the second control section. Thus, when data is read by a serial communications of low transfer speed from the nonvolatile memory of an EEPROM (Electrically Erasable and Programmable Programming Read Only Memory), a long time has to be spent before the second control section is enabled to get the required data from the RAM after power has been turned on. This has been a problem in the prior art.
[0009] In view of the prior art described above, it is an object of the present invention to solve the problem and to provide an electric apparatus ensuring early acquisition of the parameter required for the operation when power supply has turned on the power-saving mode.
SUMMARY OF THE INVENTION
[0010] An embodiment of the present invention includes a dual port RAM 41 that is accessible by a first controller 21 and a second controller 31 independently of each other; and a memory control circuit 42 for controlling the data read/write operations from and to a nonvolatile memory 37 connected under the command thereof; wherein the memory control circuit 42 further includes: a function for loading the data stored in the nonvolatile memory 37 into the dual port RAM 41 when a predetermined startup conditions have been met; and a function of writing the data written by the first control section 21 into the dual port RAM 41 , into the nonvolatile memory 37 .
[0011] According to the embodiment, allows the first control section 21 and second control section 31 to access the dual port RAM 41 independently of each other. When the first control section 21 has written into the dual port RAM 41 the data to be stored in the nonvolatile memory 37 or when a predetermined write command is issued after writing, the memory control circuit 42 writes the data from the dual port RAM 41 into the nonvolatile memory 37 .
[0012] When a predetermined startup condition has been met, e.g. when the power has turned on, the memory control circuit 42 writes the data of the nonvolatile memory 37 into the dual port RAM 41 . This procedure allows the same data as that stored in the nonvolatile memory 37 to be read from the dual port RAM 41 after the memory control circuit 42 writes the data of the nonvolatile memory 37 into the dual port RAM 41 .
[0013] The type of startup condition does not affect the arrangement. In addition to turning on of power, the startup condition can be inputting of some form of startup signal from the control section and other circuits. The first control section 21 and second control section 31 can be arranged in any configuration so long as the second control section 31 is actuated by using the data provided by the first control section 21 . There is no restriction to the functions or controls of each control section.
[0014] The data exchange speed is increased when 8-, 16- or 32-bit parallel communications are used for interface between the first control section 21 , second control section 31 and dual port RAM 41 . To put it another way, many of the less costly EEPROM use serial communications method to read and write data. Thus, data read/write speed is higher when the dual port RAM 41 is capable of parallel access than when direct access is made to the EEPROM.
[0015] Further, the memory control circuit 42 writes the data of the nonvolatile memory 37 automatically into the dual port RAM 41 when power has turned on. If the electric apparatus is turned on simultaneously with the first control section 21 and second control section 31 , the data of the nonvolatile memory 37 is put into the dual port RAM 41 simultaneously with initialization by these control sections.
[0016] The present invention provides an electronic apparatus includes a first controller 21 and second control section 31 ; and a power-saving mode for turning off the power of a first controller 21 and second control section 31 in this power-saving mode, except for the circuit that monitors the causes for returning from at least this mode; wherein the electronic apparatus further includes: a dual port RAM 41 that is accessible by a first controller 21 and a second controller 31 independently of each other; a nonvolatile memory 37 ; and a memory control circuit 42 for controlling the data read and write operations from and to the nonvolatile memory 37 ; the electronic apparatus further characterized in that the first control section 21 writes into the dual port RAM 41 the data used by the second control section 31 ; the memory control circuit 42 writes into the nonvolatile memory 37 the data written by the first control section 21 into the dual port RAM 41 , and loads the data of the nonvolatile memory 37 into the dual port RAM 41 at the same time when power has turned on; and the second control section 31 operates by obtaining data from the dual port RAM 41 .
[0017] According to the embodiment, allows parallel execution of initialization by the first control section 21 and second control section 31 , and capturing the data of the nonvolatile memory 37 into the dual port RAM 41 by the memory control circuit 42 when power has turned on, including the case of turning on from the power-saving mode. Even if the initialization of the first control section 21 has not yet completed upon termination of the initialization by the second control section 31 , the second control section 31 is capable of performing operations by reading the data required by the first control section 21 from the dual port RAM 41 .
[0018] The present invention provides the aforementioned electronic apparatus wherein the second control section 31 provides facsimile communications control and monitors at least the presence/absence of incoming signals.
[0019] According to the embodiment, upon turning on of power from the power-saving mode as a result of receiving incoming signals, the second control section 31 is capable of reading the required parameter from the dual port RAM 41 , prior to termination of the initialization of the first control section 21 , and giving a reply to incoming signals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a block diagram representing the configuration of a DPRAM interface section as an embodiment of the present invention and connections with peripheral circuits;
[0021] FIG. 2 is a block diagram representing the configuration of a multifunction device as an embodiment of the present invention;
[0022] FIG. 3 is an explanatory view showing the operation of the DPRAM interface automatically started when the power supply has turned on;
[0023] FIG. 4 is an explanatory view showing the operation performed when data is transferred to the dual port RAM from the overall control CPU;
[0024] FIG. 5 is an explanatory view showing the operation performed when the overall control CPU reads the data stored in the dual port RAM of the DPRAM interface;
[0025] FIG. 6 is an explanatory view showing the operation performed when the facsimile control CPU reads the data stored in the dual port RAM of the DPRAM interface; and
[0026] FIG. 7 is a flowchart showing the operation of each portion when the power supply has turned on from either the main supply-on mode or power-saving mode.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] The following describes the preferred embodiment of the present invention with reference to drawings:
[0028] FIG. 2 shows the schematic configuration of a multifunction device 10 as an electronic apparatus with a memory apparatus of the present invention mounted thereon. The multifunction device 10 provides a facsimile function and printer function, in addition to the function of reading an original image, forming its duplicated image on recording paper and outputting it.
[0029] The multifunction device 10 has a system control section 20 for administration and control of the operations of the multifunction device 10 , and a facsimile control section 30 for providing communications control related to facsimile communications. The system control section 20 is provided with the overall control CPU 21 , ROM (Read Only Memory) 22 , RAM (Random Access Memory) 23 , nonvolatile memory 24 , PCI (Peripheral Components Interconnect) interface section 25 and ASIC (Application Specific Integrated Circuit) 26 .
[0030] The overall control CPU 21 performs the function of administering and controlling the operation of the multifunction device 10 . The ROM 22 is a read only memory for storing the program executed by the overall control CPU 21 and other fixed data. The RAM 23 is a memory for temporary storage of the data required for the operation of the overall control CPU 21 and the image data.
[0031] The nonvolatile memory 24 is a memory that keeps the stored data undeleted even after power has been turned off. It stores, for example, control parameters for controlling the overall operation of the multifunction device 10 , namely, various parameters and settings. The PCI interface section 25 is a circuit for interconnection between the bus of the overall control CPU 21 and PCI bus. Data exchange between the system control section 20 and facsimile control section 30 is performed through the PCI bus. The ASIC 26 is an integrated circuit for decoding addresses and performing other functions.
[0032] The facsimile control section 30 contains a facsimile control CPU 31 , ROM 32 , RAM 33 , CODEC (COlder DECoder) 34 , MODEM (MOdulator-DEModulator) 35 , NCU (Network Control Unit) 36 , DPRAM interface section 40 as a memory apparatus, nonvolatile memory 37 , PCI interface section 38 and power mode evaluation section 39 .
[0033] The facsimile control CPU 31 controls the facsimile transmission and reception operations. The ROM 32 stores the program run by the facsimile control CPU 31 and various fixed data. The RAM 33 temporarily stores the data required for the operation of the facsimile control CPU 31 and image data to be transmitted and received.
[0034] The CODEC 34 performs the function of encoding the image data to be received, and decoding encoded data to the original data, according to a predetermined regulation. The MODEM 35 converts (modulates) digital data into the audio signal that can be transmitted to a telephone line, and converts (demodulates) the audio signal received through the telephone line into digital data. The NCU 36 sends the dial signal for calling a party for communications and detects incoming signals.
[0035] The PCI interface section 38 is connected with the PCI bus from the system control section 20 . The DPRAM interface section 40 is located between the bus of the facsimile control CPU 31 and PCI interface section 38 and is used for exchange of data between the facsimile control CPU 31 and overall control CPU 21 . The nonvolatile memory 37 is a memory for storing various parameters to be referenced when the facsimile control section 30 operates, and is connected to the DPRAM interface section 40 . The EEPROM of the type for inputting and outputting data through a serial interface is used in the nonvolatile memory 37 .
[0036] When power is supplied to the facsimile control section 30 , the power mode evaluation section 39 determines whether power is turned on from where the main power supply was off (hereinafter referred to as “main power supply on”), or power is turned on from the power-saving mode (hereinafter referred to as “power-saving mode”). When the main power supply is off, the power supply of the multifunction device 10 as a whole is turned off.
[0037] In the power-saving mode, the power supply is turned off, except for the circuit that monitors the causes for turning on from the power-saving mode. To put it more specifically, it includes the operation section for accepting user operations, the section for monitoring whether the electric apparatus receive a data from the external device or not (NCU 36 ) and a circuit (not illustrated) for turning on the power of each section when causes for turning on of power have been detected by the operation section or monitoring section.
[0038] The system control section 20 is connected with a scanner section (not illustrated), printer section and operation display section. The scanner section scans an original image and the printer section forms an image on recording paper and outputs it. The operation display section displays the information on various operation guidance and operation state for a user, and accepts various operations from the user.
[0039] FIG. 1 shows the configuration of the DPRAM interface section 40 and the connection status of the peripheral circuit. The DPRAM interface section 40 contains a dual port RAM 41 , memory control circuit 42 , facsimile control side interface section 43 and overall control side interface section 44 . The overall control CPU 21 can access the dual port RAM 41 through the overall control side interface section 44 , while the facsimile control CPU 31 can access the dual port RAM 41 through the facsimile control side interface section 43 . The memory control circuit 42 writes the data stored in the dual port RAM 41 , into the nonvolatile memory 37 , reads the data from the nonvolatile memory 37 and stores it into the dual port RAM 41 controlled by the memory control circuit 42 .
[0040] Data of a maximum 32-bit bus width can be read and written from the side of the overall control CPU 21 through the PCI bus, and access from-the facsimile control CPU 31 is made in terms of 16-bit bus width. The data of 16-bit bus width is exchanged between the dual port RAM 41 and memory control circuit 42 , and data is exchanged between the memory control circuit 42 and nonvolatile memory 37 in serial communication.
[0041] Further, the DPRAM interface section 40 has a command response dual port RAM (not illustrated) for exchanging commands and response between the overall control CPU 21 and facsimile control CPU 31 . The reset signal from the power supply monitoring circuit 50 for monitoring the power supply status of the facsimile control section 30 is inputted into the memory control circuit 42 of the DPRAM interface section 40 . The power supply monitoring circuit 50 releases the reset signal about 50 ms after the +5 volt power is supplied.
[0042] FIG. 3 shows the operation when the power supply of the DPRAM interface section 40 has turned on. If power turns on despite the logic on the side of the system control section 20 , and the reset signal from the power supply monitoring circuit 50 of the facsimile control section 30 has been released (Si), the memory control circuit 42 reads all data from the external nonvolatile memory 37 and writes it in the dual port RAM 41 (S 2 ). When all data has been loaded into the dual port RAM 41 , an internal valid flag (not illustrated) is set at “1”; thus, access to the dual port RAM 41 from the facsimile control CPU 31 and overall control CPU 21 are enabled.
[0043] FIG. 4 shows the operations when data is sent to the dual port RAM 41 from the overall control CPU 21 . The overall control CPU 21 writes the data read from the nonvolatile memory 24 on the side of the system control section 20 , into the dual port RAM 41 of the DPRAM interface section 40 (W 1 ). The data written into the dual port RAM 41 is written into the nonvolatile memory 37 by the memory control circuit 42 (W 2 ).
[0044] FIG. 5 shows the operation when reading the data stored in the dual port RAM 41 of the DPRAM interface section 40 . When power is on, all the data stored in the nonvolatile memory 37 is loaded into the dual port RAM 41 . Thus, by reading the data of the dual port RAM 41 (R 1 ), the overall control CPU 21 indirectly reads the data stored in the nonvolatile memory 37 . In cases where the overall control CPU 21 reads the data of the dual port RAM 41 , inspection is made by means of a checksum to see whether the data stored in the nonvolatile memory 37 is damaged or not.
[0045] FIG. 6 shows the operation when the facsimile control CPU 31 reads the data stored in the dual port RAM 41 of the DPRAM interface section 40 . When power supply is on, all the data stored in the nonvolatile memory 37 is loaded into the dual port RAM 41 . Thus, by reading the data of the dual port RAM 41 (R 2 ), the facsimile control CPU 31 indirectly reads the data stored in the nonvolatile memory 37 . In this case, data cannot be written into the dual port RAM 41 from the facsimile control CPU 31 .
[0046] The following describes the operations of turning on or off the power supply in the multifunction device 10 , and going in or out of the power-saving mode. The multifunction device 10 enters the power-saving mode automatically if the wait state continues for more than a predetermined time, without user operation or incoming signals. In this case, as described above, power supply is off except for the portion that monitors the causes for turning on of power.
[0047] FIG. 7 shows a flow of the operation of each portion that is performed when power is on, independently of whether the power supply has turned on from main supply-on mode or from power-saving mode. If power supply is on, the reset signal from the power supply monitor circuit is released in each of the system control section 20 , facsimile control section 30 and DPRAM interface section 40 (S 101 , S 201 and S 301 ).
[0048] When the reset signal is released, the overall control CPU 21 of the system control section 20 applies processing of initialization by the boot program (S 102 ). It also applies the processing of initialization by the application program (S 103 ). After power supply is turned on, about 20 through 30 seconds are required before termination of such processing of initialization.
[0049] When the reset signal from the power supply monitor circuit is released, the facsimile control CPU 31 of the facsimile control section 30 also applies processing of initialization (S 302 ). This processing of initialization terminates in several milliseconds through several seconds. When the reset signal is released, the DPRAM interface section 40 applies the processing of loading the data of the nonvolatile memory 37 into the dual port RAM 41 (S 202 ). This processing terminates in several milliseconds through several tens of milliseconds. Upon termination, a valid flag is set.
[0050] Upon termination of initialization, the facsimile control CPU 31 requests the overall control CPU 21 through the dual port RAM for command response to reserve an interface with the system control section 20 (S 303 and S 203 ). Further, by referring to the power mode evaluation section 39 , evaluation is made to see if power has turned on from main supply-on mode or power-saving mode (S 304 ). If power has turned on from power-saving mode (S 304 : Y), evaluation is made to see if turning on of power has been caused by an incoming signal from the telephone line or not (S 305 ).
[0051] If the turning on of power has been caused by incoming signals (S 305 : Y), required parameters are read from the dual port RAM 41 of the DPRAM interface section 40 (S 306 and S 204 ). Based on them, a primary response is given to the incoming signal (S 307 ). For example, a response for responding to the telephone number report function is returned, and processing is applied to maintain the access of the line.
[0052] While access to the line is maintained by the primary response, the initialization of the overall control CPU 21 terminates in time. Then the overall control CPU 21 reads the request for reserving an interface, stored in the dual port RAM 41 . Based on this request, the overall control CPU 21 carries out initialization of facsimile control interface (S 104 ).
[0053] Then a response to show termination of securing an interface to the facsimile control section 30 is reported by the overall control CPU 21 to the facsimile control CPU 31 through dual port RAM for command response (S 205 ). When an interface with the system control section 20 has been reserved (S 308 ), the facsimile control CPU 31 applies processing of facsimile communication by exchanging data with the overall control CPU 21 (S 309 through S 311 and S 105 through S 107 ). Upon termination of communication, the overall control CPU 21 and facsimile control section 30 enter the wait mode for a predetermined period of time, and then enter the power-saving mode.
[0054] When the overall control CPU 21 cannot return from the power-saving mode (S 304 : N) or it has returned from the power-saving mode without being caused by incoming signals (S 305 : N), there is need of applying the processing of primary response to the incoming signal. The system waits for a response from the overall control CPU 21 showing that an interface has been reserved. After confirming that an interface has been-reserved (S 312 ), processing of waiting starts.
[0055] As described above, when the power supply has turned on, the data of the nonvolatile memory 37 is automatically loaded into the dual port RAM 41 . When the system has returned from the power-saving mode due to incoming signal, it is possible to get the required parameter from the dual port RAM 41 and to give a primary response, without waiting for the termination of the initialization of the overall control CPU 21 .
[0056] The embodiment of the present invention has been described with reference to drawings. It should be understood that a specific arrangement of the present invention is not restricted to the embodiment described above. The present invention can be embodied in a great number of variations with appropriate modification and improvement, without departing from the spirit of the present invention.
[0057] For example, it is also possible to make such arrangements that data can be written into the dual port RAM 41 from the facsimile control CPU 31 . In the aforementioned embodiment, when the overall control CPU 21 has written data in the dual port RAM 41 , the data is automatically written into the nonvolatile memory 37 by the memory control circuit 42 . It is also possible to arrange such a configuration that the data is written in the nonvolatile memory 37 upon receipt of a predetermined write command.
[0058] The electronic apparatus using the same allow access to be made to a dual port RAM, instead of a nonvolatile memory. Thus, the first control section and second control section are capable of reading and writing the data to be stored into the nonvolatile memory, independently of each other, without each giving any load to the other. This arrangement ensures easy data exchange.
[0059] In cases where the data of the nonvolatile memory is loaded into the dual port RAM by turning on of power, data is loaded from the nonvolatile memory into the dual port RAM, concurrently as the first control section and second control section are engaged in initialization after turning on of power. This arrangement reduces the time required before the second control section is enabled to get the data from the dual port RAM, subsequent to turning on of power.
[0060] Further, when the first control section stores the data to be transferred to the second control section, in the nonvolatile memory in advance, then the second control section can capture the parameter from the dual port RAM, without having to wait for initialization of the first control section, after power has turned on. This allows processing to be carried out by the second control section alone. Especially when the second control section 31 controls the facsimile communications, it is possible to get the required parameters from the dual port RAM and to give a response to incoming signals, prior to termination of the initialization of the first control section, if power supply has turned on from the power-saving mode due to incoming signals. | An electric apparatus including a first controller and a second controller, a first memory which can access the first controller and the second controller, a nonvolatile memory which stores a first control parameter for the first control, a memory controller which manages the nonvolatile memory and writes the first control parameter stored in the nonvolatile memory into the memory in accordance with power ON. | 8 |
STATEMENT OF GOVERNMENT INTEREST
[0001] The invention described was made in the performance of official duties by one or more employees of the Department of the Navy, and thus, the invention herein may be manufactured, used or licensed by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND
[0002] The invention relates generally to photocapacitors that employ variation in capacitance. In particular, capacitance responds to variation in light intensity primarily, but in the alternate also responds to variation in light frequency.
[0003] Photocapacitance has been used by the scientific community for many years to investigate important aspects of semiconductor materials. By scanning the frequency of the light, various deep-level traps can be identified and characterized. For purposes of this disclosure, the term “trap” inclusively means either a trap or a recombination center, the distinction of which being that a trap generally interacts with only one species of (either) electrons or (else) holes, and a recombination center interacts with both electron and holes. In the literature, the terms are often used interchangeably.
[0004] For example, when a sudden change in capacitance is observed, the correlation to the photon energy of the light (determined by E hν =hν where h is Planck's constant and ν is the frequency) reveals the activation energy of a state within the band-gap of the material. Further, by identifying the sign of change in the capacitance, the type of trap can be determined, i.e., donor or acceptor-like. In particular, a donor type constitutes a neutral trap when filled with an electron and positively charged when empty; and an acceptor-like type represents a neutral trap when filled with a hole and negatively charged when empty.
[0005] Photocapacitance can be used to determine other information as well. There are approximately thirty variations of the photocapacitance method to determine material properties. Summary information of techniques can be found in references: P. Blood and J. W. Orton, “The electrical characterization of semiconductors,” Rep. Prog. Phys., 41, 2, pp. 157-258 (1978), and C. T. Sah, L. Forbes, L. L. Rosier and A. F. Tasch, Jr., “Thermal and Optical Emission and Capture Rates and Cross Sections of Electrons and Holes at Imperfection Centers in Semiconductors from Photo and Dark Junction Current and Capacitance Experiments,” Solid - State Electronics, 13, 6 (1970), pp. 759-88.
[0006] As mentioned, a common use of photocapacitance in the scientific community is to determine inter-band-gap state information in a semiconductor. FIGS. 1A and 1B show inter-band-gap state information of a semiconductor material, and the corresponding photocapacitance data, obtained from Blood et al. FIG. 1A shows a representational view 100 of an electron band-gap 110 between an upper conduction band edge 120 and a lower valance band edge 130 .
[0007] A photon 140 having energy E hν >0.465 eV strikes a trap within the bandgap 110 to ionize position N 1 + at 0.465 eV transferring to the resultant electron 145 sufficient energy for quantum transition to the conduction band edge 120 . FIG. 1B shows a graphical view 150 of normalized capacity as a function of photon energy E hν , with the latter as the abscissa 160 and the former as the ordinate 170 .
[0008] A series of stepped electron capacitance values 180 demonstrates a series of normalized capacity values from 0.4 eV to about 1.6 eV. Several states are identified at photon energies of 0.465 eV, 0.73 eV, 0.78 eV etc. The state at 0.73 eV shows a positive change in capacitance signifying a donor-like state. By contrast, the nearby state at 0.78 eV shows a negative change in capacitance signifying an acceptor-like state. In this manner, a photocapacitor can respond to the photon energy (frequency) as provided in various exemplary embodiments. In addition, other exemplary embodiments provide for controlling capacitance by changing the light intensity.
SUMMARY
[0009] The photocapacitor has not been commercially exploited, but such a device has advantages addressed by various exemplary embodiments of the present invention. Previously, the capacitance of commercial semiconductor capacitors could be varied by means of applied voltage. Such devices, known as varactors, require connection wires that could interfere in materials, such as electromagnetic applications, for example.
[0010] Various exemplary embodiments provide a photocapacitor device for responding to photons having at least a specified energy. The exemplary photocapacitive device includes a first portion composed of a photocapacitive material; a second portion composed of a non-photocapacitive material; and a depletion region disposed between the first and second portions. The photocapacitive and non-photocapacitive materials respectively can have first and second Fermi-energy differences.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and various other features and aspects of various exemplary embodiments will be readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, in which like or similar numbers are used throughout, and in which:
[0012] FIG. 1A is a representational view 100 of an electron band-gap with interband electronic states associated with various traps;
[0013] FIG. 1B is a graphical view of normalized conduction band capacity identifying interband electronic states as a function of photon energy;
[0014] FIG. 2 is an electron energy band diagram of a voltage controlled semiconductor capacitor known as a varactor;
[0015] FIG. 3 is an electron energy band diagram of an optical controlled capacitor known as a photocapacitor;
[0016] FIG. 4 is a graphical view of a results plot of capacitance from a photocapacitor and its sensitivity to light at high frequencies;
[0017] FIG. 5 is a graphical view of a plot of photocapacitance sensitivity to light intensity at high frequencies;
[0018] FIG. 6 is an augmented graphical view of a results plot from a photocapacitor and its sensitivity to light at a low frequency;
[0019] FIG. 7 is a representational diagram of a single deep level interband state, or trap;
[0020] FIG. 8 is a cross-sectional view of an example two-junction photocapacitor device; and
[0021] FIG. 9 is a representational view of a band diagram for a junction.
DETAILED DESCRIPTION
[0022] In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized, and logical, mechanical, and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
[0023] Photocapacitance has not been exploited for commercial, defense or other application, so far as known. In various exemplary embodiments, photocapacitance can yield devices in which the value of capacitance can be changed by the intensity of light. This is markedly different from the way the technical community uses photocapacitance where the capacitance changes due to the wavelength of the impinging light, or equivalently its photon energy.
[0024] Photon wavelength λ relates to the energy of light (as proportional to the reciprocal of frequency ν) by E hν =hc/λ=hν where h is Planck's constant and c is the speed of light. Further, techniques for fabricating the photocapacitor structure are provided that can be used to control desirable properties. Artisans of ordinary skill, e.g., electrical engineers, will find many applications for a photo-sensitive capacitance without departing from the scope of the claims, some uses of which are identified below.
[0025] One application for photocapacitance is for tunable metamaterials. Typical metameterials depend on resonances are inherently single frequency. This limitation can be overcome by employing tunability. Metamaterials can be used in lenses, cloaking envelopes, antennaes and other electromagnetic applications.
[0026] Another application of the photocapacitor includes a wide dynamic range optical sensor. For example, photocapacitors can be fabricated from undoped semi-insulating (USI) gallium arsenide (GaAs) that has sensitivity to light energy at the dominant active trap (second energy level EL2) with an ionization energy of 0.684 eV at 300K. See D. C. Look and Z.-Q. Fang, “On the energy level of EL2 in GaAs,” Solid - State Electronics, 43, 7 (1999), pp. 1317-19 that indicates an energy value less than the band-gap of 1.424 eV at room temperature (293K).
[0027] The photocapacitor as described utilizes any one of the interband states as shown in FIG. 1A . Rather than employ light of sufficient intensity to ionize the traps associated with that state to a maximum amount, as performed in the scientific community for material characterization purposes, various exemplary embodiments provide a photocapacitor that continuously responds to variable light intensity, thereby effectively riding up or down the sharp transition in capacitance associated with one of in the states shown in FIG. 1B . Any state can be chosen for use, or multiple states can be utilized in various exemplary embodiments.
[0028] Various exemplary embodiments describe at least one device called a photocapacitor based on a variation of the photocapacitance effect. The photocapacitance effect has been used in scientific discovery to learn properties of semiconductor materials. However, this phenomenon has not otherwise been exploited for purposes of producing a useful device. The photocapacitor described herein employs the light intensity level to control the inherent variation in capacitance, in contrast to the scientific use that normally uses light frequency to obtain information from a corresponding variation in capacitance. Various exemplary embodiments for designing a photocapacitor are described, which can be used to optimize photocapacitor design parameters for useful applications.
[0029] In particular, the photocapacitor uses the photocapacitance effect of a semiconductor or semi-insulator material with one or more junctions. Within this disclosure, the term “semiconductor” indicates any one of semiconductor, semi-metal or semi-insulator. The junctions can be alternatively made from one or more of metallic materials, semiconductor materials, semi-metal materials, and quasi-photocapacitor semiconductors (doped differently from the photocapacitor). The junctions can serve both to form the photocapacitance region in a desired way and as electrical terminals.
[0030] One example application enables tunability of electromagnetic devices without incorporating wires that can otherwise interfere with such devices. Also, photocapacitance can be used for novel types of sensors and imagers of electromagnetic radiation in the infrared, visible or ultraviolet or higher frequency parts of the spectrum, depending on the material, and trap level within the material. Photocapacitance can be used to detect charged or uncharged particles where the particle plays the role of a photon change in capacitance. As another example, electrical engineers employ photocapacitance in electronic circuit applications in which sensitivity to light controls part of the circuit.
[0031] Additional example applications of photocapacitance devices include the coupling of output signals of optical communications, or optical computer components and devices, to standard solid state electronic devices and systems. Other examples can be found in tunable electromagnetic devices that include but are not limited to filters (e.g., notch, bandpass, high-pass, lowpass), waveguides that operate above or below the cut-off region, absorbers, transmitting or receiving antennae, and other tunable electromagnetic devices. In yet another example, photocapacitance can be used as a sensor, or part of a detector, in which light detection is secondary to detection of a primary phenomenon, such as chemical or biological agents for example.
[0032] In various exemplary embodiments, the use of materials at junctions can control the Fermi-energy position thereby forming a photocapacitor with controllable and desirable properties. The control of the Fermi-energy position at the junction relates to the Fermi-energy position within the bulk material, which can also be controlled. At thermal equilibrium, Fermi-energy remains steady. Outside of thermal equilibrium, such as through photo injection for example, the “imaginary” Fermi-energy is sometimes called Imref for Fermi written backwards.
[0033] One well known application involves tuning a split-ring resonator (SRR). This is accomplished by changing the capacitance in the inductorcapacitor circuit of an SRR. Success of this method is provided in U.S. Pat. No. 7,525,711 to Rule et al., achieving a tunable range ratio of 15:1. See also K. A. Boulais, D. W. Rule, S. Simmons, F. Santiago, V. Gehman, K. Long, and A. Rayms-Keller, “Tunable split-ring resonator for metamaterials using photocapacitance of semi-insulating GaAs,” Appl. Phys. Lett., 93, 043518 (2008).
[0034] Varactor diodes represent an example alternative technique for varying capacitance, in this case by altering the applied voltage across its terminals. However, these suffer from the limitation that wires must be used to transfer a voltage to each device. The wire can interfere with an application such as for example, electromagnetic applications unless careful and restrictive design considerations are employed. See D. Wang, H. Chen, L. Ran, J. Huangfu, J. A. Kong, and B. Wu, “Reconfigurable cloak for multiple operating frequencies,” Appl. Phys. Lett., 93, 043515 (2008).
[0035] In an exemplary embodiment, a photocapacitor can be used in conjunction with the varactor effect within the same device. Such operation includes a choice of capacitance variation methods via optical, electrical or both simultaneously.
[0036] A single junction semiconductor device can be formed using component configurations such as n-p, n-i, and p-i, where n represents n-type semiconductor, p represents p-type semiconductor, i represents insulating-type semiconductor. Alternatively, the junctions can be metal-semiconductor, e.g., Schottky junctions, such as m-n, m-p, and m-i, where m represents a metal. The components at either end need not be composed of the same material. In some multi-junction devices, photocapacitance may form only at one of the junctions or at multiple junctions. Combinations of these junctions can be used to make multi-junction devices so long as the junction includes a region of photocapacitance.
[0037] Capacitance naturally develops when two semiconductors of different types (n, p or i) or a metal and a semiconductor are brought into intimate contact. This contact should be distinguished from an ohmic contact that lacks such capacitance. The capacitance junction can be produced by diffusion of one material into another material, or by epitaxial growth of one material onto another, or by some other methodology established in the semiconductor art.
[0038] Capacitance forms over a region naturally depleted of free charge known as the depletion region. Capacitance C changes over this region as the charge in the region shifts between a charge state and a neutral state according to the definition:
[0000]
C
≡
Q
V
,
(
1
)
[0000] where Q is the effective charge in the region, and V is a measuring voltage across that region.
[0039] For a p-n junction, the capacitance C is determined as shown by R. S. Muller and R. I. Kamins, Device Electronics for Integrated Circuits, 2/e, John Wiley & Sons, New York (1986), as:
[0000]
C
=
ɛ
s
x
d
=
q
ɛ
s
2
(
1
N
a
-
1
N
d
)
(
φ
i
-
V
a
)
,
(
2
)
[0000] where q is the elemental charge on a free electron, x d is the depletion width, ε s is the permittivity of the semiconductor, N a and N d are the ionized doping densities of the p-region (acceptor) and the n-region (donor), respectively, φ i is the built-in (i.e., intrinsic, as a term of art) potential that naturally occurs across the junction, and V a is the applied potential. Artisans of ordinary skill in semiconductor physics will recognize that the depletion capacitance has been normalized to cross sectional area. In the varactor, the applied potential V a dynamically controls the capacitance. This voltage can be assumed to be zero for purposes of this disclosure in order to describe photocapacitance, unless otherwise specified.
[0040] Note that eqn. (2) applies to a single p-n junction and capacitance might differ for multi-junction capacitors. For a two-junction capacitor, junction-1 and junction-2 are arranged in series, and their respective capacitances add in series as
[0000]
1
C
t
=
1
C
1
+
1
C
2
,
(
3
)
[0000] where C t represents the series equivalent of the capacitances C 1 and C 2 of the first and second junctions.
[0041] Deep level traps in a depletion region are mostly responsible for the photocapacitance effect. Ignoring shallow donors and acceptors, eqn. (2) can be rewritten in the form:
[0000]
C
d
=
q
ɛ
s
N
t
+
2
φ
i
,
(
4
)
[0000] where N t + are the ionized traps. Free carriers constitute electrons and holes. Generation and recombination is influenced thermally as well as optically.
[0042] In photocapacitance, the capacitance is controlled by optically ionizing these traps. This simple model can describe the operation of photocapacitance, but often necessitate numerical techniques to accurately include all influences of free carrier drift, free carrier diffusion, trap generation of electrons and holes, trap recombination of electrons and holes, and direct or indirect recombination of electrons and holes (between the conduction and valance bands). In such cases, photocapacitance may still exist despite the depletion region not being fully depleted of free charge. Any of these processes can have strong influences on the behavior of a photocapacitor. The trap electrons are many orders of magnitude fewer than the valance electrons.
[0043] FIG. 2 shows a first electron energy band diagram view 200 of a Schottky junction between a metal and an n-type semiconductor established as a varactor. On the left is a metal conductor 210 . On the right is a semiconductor 220 . A depletion region 230 of distance x d separates the metal 210 and semiconductor 220 from each other. The potential difference between the metal 210 and semiconductor 220 is q (φ i −V a ).
[0044] Optical stimulation of a center depletion region 230 results in only minor response because there exist no deep level traps, and because the shallow traps N d + (that represent shallow ionized donors) are typically already fully ionized by thermal energy at room temperature. Thus, the only effective manner to dynamically change capacitance involves using V a according to eqn. (2).
[0045] FIG. 3 illustrates an energy band diagram of a junction established as a photocapacitor. The active semiconductor has deep level traps. This constitutes one major distinction with the varactor of FIG. 2 . Such traps can exist as defects, such as a result of some growth techniques in GaAs, for example, or as deliberately embedded impurities. The deep level trap known as EL2 represents an example of a defect in GaAs, presumed to be an arsenic anti-site. The density of EL2 traps can be controlled through some growth techniques (such as the Czochralski method). Copper (Cu) constitutes an example of a dopant impurity that produces a deep level trap in GaAs.
[0046] The photocapacitance region can include shallow dopants or impurities and deep traps as ionized N quantities as distinguished components as:
[0000]
C
d
=
ɛ
s
x
d
=
q
ɛ
s
(
-
N
a
-
+
N
d
+
+
N
tt
+
+
Δ
N
to
+
)
2
φ
i
,
(
5
)
[0000] where impurities constitute the first two parenthetical terms in which N a − represents ionized shallow acceptors, and N d + represents shallow ionized donors. Artisans of ordinary skill will recognize that pure intrinsic GaAs devices can be difficult to fabricate in ideal form, and sometimes N a − and N d + can represent unintentional impurities. Deep level traps may be used to compensate for the unintended dopants so that the USI behaves as though being nearly pure. Also, deep level traps include the last two parenthetical terms in which N u + represents thermally induced ionized traps, and ΔN to + represents variable optically induced ionized traps.
[0047] Often, the charge neutrality under thermal equilibrium conditions balance in eqn. (5) dictates that the term −N a − +N d + +N u + =0, which leaves:
[0000]
C
d
=
ɛ
s
x
d
=
q
ɛ
s
Δ
N
to
+
2
φ
i
.
(
6
)
[0000] This procedure reveals an advantage in eqn. (6) in that the capacitance variation can be quite sensitive to optical stimulation. The charge neutrality effect indicates that small changes (relative to the densities N a − , N d + and N u + ) in ΔN to + can have pronounced effect on capacitance. Further, the optical amplitude can be used to control the capacitance as opposed to changes in optical frequency as typically used in the scientific community, although both controls can be used separately or together.
[0048] The use of junction materials with alternate specifications to fabricate photocapacitors represents another advantage of this process. By using doped semiconductors, metals, or even chalcogenides, the built-in potential φ i , can be adjusted such that the specified photocapacitance fits a desired function. The relationship between the built-in potential and the capacitance is evident in eqns. (2) through (6).
[0049] In some cases, such as typically in GaAs, the Fermi energy is pinned (i.e., restricted) at the semiconductor device. This renders the built-in potential φ i difficult to modify. The reasons for pinning are not well understood but at any rate can be compensated for by creating a junction of the same material thereby unpinning the Fermi energy. Controlling the built-in potential of the photocapacitor potential φ i can be accomplished by doping the added material, thereby constituting another advantage of this process. This doping material can be, for example, a p-type GaAs on semi-insulating GaAs.
[0050] Methods to illuminate the photocapacitor can include direct illumination by a light-emitting diode (LED), an organic LED, a laser, a thermal source or other means so long as the light energy is sufficient to ionize the desired traps. Other means include light-guides that can carry the optical intensity to the photocapacitor from a distance away.
[0051] Typically, light having photon energy sufficient to ionize a trap can be used to induce the photocapacitance effect. For photon energy less than the bandgap energy, the light can travel far through the semiconductor to achieve a greater effect. However, light having photon energy greater than the bandgap can be used for some device applications. The photocapacitance effect can be used in conjunction with a varactor. Also, a varactor can be used as the primary source of capacitance, which is thereby controlled through a photovoltaic device, thereby creating a different type of photocapacitor. A varactor can be used to set an effective bias, or sensitivity range for the photocapacitance effect, for example. Light sensor applications can take advantage of a wide range of capacitance values, normally found in photocapacitance, thus enabling creation of a wide dynamic range sensor. The sensor can be fabricated in a pixel array, for example, to be used in a wide dynamic range imager.
[0052] Junction capacitance in a semiconductor occurs near a Schottky junction (non-ohmic, metal-semiconductor junction), or a p-n junction. This capacitance exists across the depletion region 230 , and is recognized by those skilled in the art of semiconductor device physics. As described above, FIG. 2 represents the Schottky's electron energy band diagram 200 that shows a depletion region near the junction of a metal 210 and an n-type semiconductor 220 . An analogous capacitance exists across the depletion region 330 for the photocapacitor's electron energy band diagram 300 . The depletion-width is given by x d where the energy bands curve upwards.
[0053] The built-in electric field, due to the energy band curvature between the metal 210 and the semiconductor 220 , explains the reason the depletion region 230 is void of free electrons, being swept out. Also, this explains why free electrons (−charge) remain in the bulk semiconductor material 220 where the electric field may be assumed to be small or null. The depletion capacitanced forms across the depletion region 230 .
[0054] For Schottky junctions formed with p-type semiconductors, the curvature of the energy bands in the depletion region 230 would curve down-wards instead of upwards, and the depletion region 230 would be void of hole-type charge in a similar way. Depletion regions are also found in p-n junctions in which the depletion regions form within both the n-type and the p-type materials dispersed according to their doping density (N d or N a ) as provided in eqn. (2).
[0055] The Fermi-energy position in the bulk semiconductor 220 and 320 is often determined under thermal equilibrium conditions from Fermi-Dirac statistics. The depletion regions 230 and 330 stem from proper alignment and control of the relative Fermi-energy positions at the junction, and within the respective semiconductors 220 and 320 . One advantage of this method is that metals, semiconductors, or other materials can be used to control the Fermi energy difference, thereby controlling the built-in potential φ i .
[0056] In some cases, such as typically in GaAs, the Fermi energy is pinned (i.e., restricted) at the semiconductor surface. This renders the built-in potential φ i difficult to modify. The reasons for the pinning are not well understood but in any case can be compensated for by making a junction of the same material. Controlling the built-in potential of the photocapacitor φ i can be accomplished by doping the added material, constituting another advantage of this process. This doping material can be, for example, an n-type GaAs on semi-insulating GaAs.
[0057] The EL2 band-gap restriction is only due to the high level of absorption typical for above band-gap photon energy that generally prevents light from penetrating far enough into the semiconductor 320 as shown in FIG. 3 . This application can take advantage of a wide range of capacitance values normally found in photocapacitance, thus making a wide dynamic range sensor. The sensor can be fabricated in a pixel array, for example, to be used in a wide dynamic range imager.
[0058] Yet another application of the multi-junction photocapacitor includes an electronic circuit that has sensitivity to light. For example, photodiodes or phototransistors are often used to detect light and perform a task in response. The multi-junction photocapacitor can be used similarly in circuits to perform a task in response to light, in which the task can include switching a device on or off, or controlling the state of a device in a continuous way, or detecting an amount of light impingent on the circuit, or to tune a resonant circuit or frequency. Other electro-optic circuit uses may be also considered and this disclosure should not be limited to those applications discussed here.
[0059] Inducing an optical control signal onto a photovoltaic device constitutes another process to provide photocapacitance, in which the photovoltaic device reacts by inducing a voltage and in turn changes V a in eqn. (2). The photovoltaic device can be of a semiconducting nature, a semi-insulating nature or a polymer nature. Very little current (leakage current only) is drawn from the photovoltaic device because the junctions represent back-to-back diodes in reverse bias mode.
[0060] The depletion approximation is known to those skilled in the art and has been used to derive eqn. (6). However, with involvement of deep level traps, or small amounts of energy band bending, the depletion approximation may no longer be valid, and numerical techniques may be required to describe the depletion region quantitatively. In some cases, the depletion region might not be completely depleted of free charge. Nonetheless, eqn. (6) is useful to describe photocapacitance qualitatively.
[0061] Trap dynamics includes the recombination and generation of electrons and holes with the conduction band and valance band, respectively. The trap dynamics represent an important part of photocapacitance and must be included in numerical solutions. These trap dynamics include interactions with phonons (thermal), photons or other particles, and often described using Shockley-Hall-Read statistics, known to artisans of ordinary skill in semiconductor physics. See W. Shockley and W. T. Read, “Statistics of the Recombinations of Holes and Electrons,” Phys. Rev., 87, 835 (1952), and R. N. Hall, “Electron-Hole Recombination in Germanium,” Phys. Rev., 87, 387 (1952). Another parameter that can be controlled includes the ionization energy of the trap density N T , also described in Shockley and Read.
[0062] Generally, a strong photocapacitance effect requires deep level traps within the band-gap of the semiconductor 320 in which the ionized traps (+charge) are near mid-gap with an ionized trap density N T + . These traps are assumed to be donor type, and so free electrons are shown in the conduction band of the bulk material semiconductor 320 due to trap ionization. For deep traps (although not necessarily near mid-gap), thermal energy at room temperature may generally not be enough to ionize all the traps. For the USI example above, only about 10% of the traps are ionized at room temperature. This can reserve up to 90% of the traps available for ionization by light. The process is similar for acceptor type traps where the ionized trap would be a negative charge.
[0063] Without controlling the photocapacitor using voltage, as in a varactor, the applied voltage V a can be assumed to be zero. In such cases, the depletion capacitance C d can be approximated as:
[0000]
C
d
=
ɛ
s
x
d
=
q
ɛ
s
N
T
+
2
φ
i
.
(
7
)
[0000] Note that N d + in eqn. (6) is replaced with N T + , the ionized trap density. From eqn. (7) one can observe that by changing the amount of trap photo-ionization based on trap density N T + , a change in capacitance may result. Because N T + varies as a function of light intensity by the proportion ΔN T +∝P 4 , capacitance can be monotonically and continuously controlled through the intensity of light based on its photosensitivity. Experimental results show that control can be achieved by an intensity of 5 mW/cm 2 . The amount of band bending within the photocapacitor depletion region 330 ( FIG. 3 ) is less than that of the analogous varactor depletion 230 ( FIG. 2 ). For a very small band bending in which the built-in potential is less than the thermal energy, the depletion capacitance C d can be further approximated as:
[0000]
C
d
=
ɛ
s
L
D
,
(
8
)
[0000] where L D is the Debye length. The Debye length is generally not a function of the built-in potential φ i , and thus the photocapacitors, in these cases, do not suffer from non-linearity. For example, in an electromagnetic application, the electromotive force (EMF) produced by the field across the photocapacitor does not distort the capacitor, which in turn can influence the electromagnetic signal in a non-linear manner such as producing unintended harmonics in the signal.
[0064] By contrast, the case of a varactor as described by eqn. (6) shows that any change in applied voltage is summed with the built-in potential φ i , and thus affects the energy band bending as shown in FIGS. 2 and 3 . Thus, if the capacitor is used in a resonator, the alternating voltage affects the capacitance in a non-linear way, which can generate harmonics adverse to the application.
[0065] Exact analytical forms for the depletion capacitance may be difficult to derive analytically. However, the relationship between capacitance and light intensity can be empirically determined by experiment. FIG. 4 depicts a response curve in a logarithmic plot 400 for exemplary results from a photocapacitor fabricated from USI GaAs at a fixed light wavelength 975 nm. Aluminum contacts were used to form a two-junction device. Light irradiance P in watts-per-square-centimeter represents the abscissa 410 and depletion capacitance C d in pico-farads is the ordinate 420 . ( FIG. 6 provides another complimentary plot, described further herein.) Experimental results that demonstrate control can be achieved for example by an intensity of less than 5 mW/cm 2 .
[0066] A threshold level 430 at 100 pf denotes the maximum capacitance for power-law correlation. In this example, the data, represented by an empirical line 440 of measured values, show the relationship between capacitance and USI to be a correlation line 450 corresponding to the proportional relation C d ∝P 1.1 , where P is the flux intensity of light impinging on the photocapacitor. That proportional relation remains valid over much of the photocapacitance range. More exact theoretical relationships can be determined using numerical techniques.
[0067] Location of a deep level trap can significantly influence the behavior of photocapacitance, and thus can be used to design photocapacitors with desired properties. For example, if a trap is located above midgap, then a photon having energy less than the bandgap energy E g or hν<E g can be used to generate electrons only. Typically traps affect both electrons and holes, and these depend on the trap dynamics.
[0068] Various exemplary embodiments disclose techniques to fabricate photocapacitors towards controllable and desirable properties. Two fundamental categories of processes can be used to control the state of photocapacitance: first—control the type, location and density of deep level traps, and second—control the structure that in effect, controls the relative Fermi-energy throughout the structure. Through end of this section, the USI example can be assumed as the exemplary condition. USI photocapacitors have many of the elements that demonstrate the advantages of the methods in this, such as for type, energy location and density of deep level traps.
[0069] For USI, eqn. (7) may be rewritten to account for the effects of unintentional shallow donor atoms of density N d + , and unintentional shallow acceptor atoms of density N a + , which are usually present in USI. Artisans of ordinary skill recognize that true intrinsic GaAs devices can be difficult to fabricate. Often, such a device includes unintentional states within the band-gap. Deep level traps may often be used to compensate for the unintended dopants so that USI behaves as though it were nearly pure, rendering semi-insulating behavior by depletion capacitance:
[0000]
C
d
=
q
ɛ
s
(
N
d
+
-
N
a
-
+
N
Tt
+
+
Δ
N
To
+
)
2
φ
i
,
(
9
)
[0000] where N d + and N a − represent donor and acceptor densities assumed to be fully ionized and constant, the fully ionized trap density N T + has been separated into a constant thermal component N Tt + , and an optical component ΔN To + that varies with light intensity. Under select circumstances, the sum of donor, acceptor and trap densities approach zero, as N d + +N a − +N Tt + →0.
[0070] Moreover, eqn. (9) for depletion capacitance can be further simplified by summing the thermal ions as:
[0000]
C
d
=
q
ɛ
s
(
N
it
+
Δ
N
To
+
)
2
φ
i
,
(
10
)
[0000] where N it represents the density summation over all thermally ionized species assumed to be constant with a value given at a particular temperature.
[0071] From eqn. (10), light intensity ΔN To + must overcome density summation N it for any change in capacitance to occur. Thus, sensitivity and enhanced range can be dramatically improved by fabricating the semiconductor material such that N it =0. This can be accomplished through tight control, or the intentional addition of shallow impurity densities to null the deep-level thermal-ion density of the traps N Tt + . Note that only the net impurities for density summation N it need vanish and not each individual species.
[0072] FIG. 5 shows a graphical plot 500 of reciprocal square root of depletion photocapacitance as a function of laser power in milli-watts as the abscissa 510 . The result of this effect in the plot 500 illustrates reciprocal capacitance 1/√{square root over (C d )} as the ordinate 520 against laser power.
[0073] The diamond points along solid curve 530 represent experimental data for light wavelength fixed at 975 nm at low frequency (1 MHz). The plateau in the data results from a non-zero thermal-ion density N it . The dash line 540 represents the extension of range and sensitivity (thus necessitating less intensity to initiate a change in capacitance) of photocapacitance in the limit as N it →0, indicating enhancement of photocapacitance sensitivity and range resulting from a reduced fixed thermal ion density in the semiconductor material.
[0074] FIG. 6 depicts an augmented logarithmic plot 600 for exemplary results from a photocapacitor fabricated from USI at a fixed light wavelength 975 nm. Light intensity P in watts-per-square-centimeter represents the abscissa 610 and depletion capacitance C d in pico-farads is the ordinate 620 . Diamond data points form a sinusoidal quarter-wave curve 630 that approaches 400 pF capacitance at peak intensity above 100 W/cm 2 .
[0075] The fill trap density normalized to the total number of traps f T , as fill factor, can be solved using Shockley-Hall-Read statistics as:
[0000]
f
T
=
e
p
th
+
e
p
o
+
C
n
e
n
th
+
e
n
o
+
C
n
+
e
p
th
+
e
p
o
+
C
p
,
(
11
)
[0000] where e n th and e p th are the thermal electron and hole emission rates, respectively, e n o and e p o are the optical electron and hole emission rates, respectively, and C n and C p are the electron and hole capture rates (by the traps), respectively. With no optical stimulus, eqn. (11) reduces to
[0000]
f
T
=
e
p
th
+
C
n
e
n
th
+
C
n
+
e
p
th
+
C
p
=
0.91
,
(
12
)
[0000] where the fill factor value 0.91 is calculated for typical values in USI.
[0076] On the other hand, with levels of optical stimulation high enough that the optical effects overcome the thermal effects, the fill factor f T in eqn. (11) reduces to:
[0000]
f
T
=
e
p
o
e
n
o
+
e
p
o
=
σ
p
o
σ
n
o
+
σ
p
o
=
0.375
,
(
13
)
[0000] using typical values for USI, and where e n o =I o σ n o and e p o =I o σ p o where σ n o and σ p o are the optical ionization cross sections at the wavelength of light, and the optical intensity I o , divides out of the equation. Thus, the optical ionization ΔN To + n eqn. (10), can vary between 9% and 62.5% of the total trap density N T .
[0077] The reason for this limit of 62.5% of the total trap density N T is because the trap exists at mid-gap, and so the energy of the light used to ionize those traps (by generating electrons) can also neutralize the traps (by generating holes) concurrently. Thus, photocapacitance range can be improved by selecting a deep level trap at an energy that is not at mid-gap.
[0078] For example, FIG. 7 shows a representational diagram 700 of a deep donor-type trap closer to the conduction band than to the valence band. By selecting light with a photon energy as the product of Planck's constant and frequency hν, sufficient to ionize those traps through electron generation, but insufficient to neutralize the traps through hole generation, then σ p o =0. In turn, the corresponding fill factor f T in eqn. (13) would be zero, meaning that the trap level could have a much higher level of ionization.
[0079] FIG. 7 depicts the energy band diagram 700 showing a deep trap at energy slightly closer to the conduction band edge than the valence band edge. A band-gap 710 exists between a conduction band edge 720 and a valance band edge 730 , with a mid-gap energy level 740 in between. A deep trap energy 750 (such that thermal energy does not ionize a significant quantity of traps) lies between the mid-gap energy 740 and the conduction band edge 720 . This enables an electron to absorb photon energy for jumping to a higher level. Photon energy hν can be chosen to have sufficient energy to generate electrons, thereby ionizing the traps, such as at energy 750 , but not enough energy to generate holes for neutralizing the trap.
[0080] Another advantage of this process includes reducing capacitance loss because holes would not be generated that could be swept across the depletion region. Yet, another advantage is that the number of p-type shallow acceptors can be increased to match an increased number of deep level donors, thereby increasing the number of free charge in the bulk region while maintaining the condition N it =0. This further and significantly decreases loss by increasing the density of free carriers in the bulk region. Another process involves inserting dopants that constitute true traps at mid-gap, and not recombination centers. Yet another advantage involves the ability to employ multiple traps to control both the electron generation and the hole generation by different wavelengths of light.
[0081] Various exemplary embodiments provide for controlling design parameters by imposing control of the Fermi-energy levels throughout the structure. Ultimately, this Fermi-energy design process controls the band-bending that creates the depletion region, and therefore the depletion capacitance. As previously described, the band-bending may be subject to the Fermi-energy position at the junction relative to that in the bulk (e.g., the semiconductor). For this disclosure, a step junction may be assumed rather than a graded junction. Alternatively, graded junctions can be used for control in a similar manner, and the concepts herein are not restricted to step junctions.
[0082] Generally, a junction may be created at one surface representing a single photocapacitor. At least one photocapacitor can be formed in a single device. However, for purposes of this disclosure, only single junctions are described with the understanding that these single junctions or single photocapacitors do not limit the scope of these embodiments.
[0083] Each junction can be fabricated as n-c, p-c, m-c, or combination thereof, where n represents an n-type semiconductor, p represents a p-type semiconductor, c represents a photocapacitive material, and m represents a metal. The material in contact with the c material in all cases is utilized to control the Fermi-level at the c surface. Each junction can be fabricated as i-c where i is an insulator. This process disposes a fixed capacitor formed by the insulator in series with the photocapacitor. The process further reduces loss by preventing the flow of charge across the insulator.
[0084] For m-c junctions, common knowledge in the art of semiconductor physics includes that the band bending is a function of the difference in work functions between the metal Φ M , and the semiconductor Φ S . Thus, the built-in potential φ i in eqn. (10) can be written as:
[0000] qφ i =q (Φ M −Φ S ), (14)
[0000] where the product qφ i (of electronic charge and built-in potential) represents the amount of energy band bending in the depletion region.
[0085] Thus, according to eqn. (10), the initial dark value of capacitance can be controlled by this method through a proper selection of work-functions of the materials. Different metals can be used that have different work functions Φ for any particular semiconductor. Similarly, different photocapacitive semiconductors can be used that have different work functions for any particular metal.
[0086] This technique can be used with many photocapacitive materials, but not all. For example, artisans of ordinary skill will recognize that USI has an electrically active surface that tends to set the Fermi-energy at a value nearly independent of the type of metal used at the junction. In such cases, intermediate layers can be used to reduce Fermi-energy pinning.
[0087] For example, some chalcogen elements, e.g., selenium (Se) and sulfur (S), have been shown to have a Fermi-energy unpinning effect in GaAs. Thus, sandwiching a thin chalcogen layer between the metal and the photocapacitor enables Fermi-energy control at the junction. This junction would be designated as m-h-c where h represents chalcogen.
[0088] Another process to unpin the Fermi-energy position at the surface of the semiconductor uses the same type of semiconductor for the junction instead of a metal, but one that is doped differently than the photocapacitive material. This technique naturally unpins the Fermi-energy.
[0089] FIG. 8 shows an example of a two-junction photocapacitor device 800 with an exemplary p-c-p structure used to unpin the Fermi-energy at the photocapacitor surfaces. In particular, the device 800 includes a c-type photocapacitive material 810 flanked by a first p-type material 820 on the left and a second p-type material 830 on the right. Depletion region distances x d1 and x d2 separate the c-type material 810 and p-type materials 820 , 830 from each other.
[0090] FIG. 9 shows an energy band diagram 900 for one of the junctions in the structure the device 800 . This photocapacitor includes a p-c structure to unpin the Fermi-energy at the p-c surface. The p-type region 910 corresponds to the p-type material 820 , 830 in the device 800 . The c-type region 920 corresponds to the c-type material 810 . A boundary 930 separates the regions 910 and 920 and lies within a photocapacitance depletion region 940 having distance x d . The p-band-gap 950 having a Fermi-energy difference ε f-p has a higher level than the c-band-gap 960 with a Fermi-energy difference e f-c . The gaps are separated by the distance denoting the total depletion region 970 .
[0091] This technique can also be used, to some extent, to control the initial capacitance (dark value) because those of ordinary skill recognize that the doping level of the p-type material can influence the depletion width in the photocapacitance material. Practical design considerations may suggest a p + -type material that is highly doped and more conductive to help control loss in the photocapacitor system. Thus, a junction of this type would be p + -c.
[0092] More complex structures can be used to further improve performance, such as an m-p + -c structure, which enables wire bonding to a metal contact, and that these examples are not limiting. For example, other photocapacitance materials exist in which the traps are acceptor-like. Such structures may involve n-type, or n − -type junction materials.
[0093] As another example, use of a photovoltaic device can also generate a voltage that, in turn, controls the capacitance of a varactor. This technique can include many advantages of the techniques described above because external wires to an external power supply are not necessary for various exemplary embodiments.
[0094] A photocapacitor can also be fabricated using a photovoltaic effect found in some polymers. The photocapacitor can also be fabricated from materials other than semiconductors that demonstrate charge separation in response to light. Poly-9-vinylcarbazole and a variety of other polymers with aromatic or heterocyclic chain units exhibit photo-induced discharge. The photo-response can be strongly improved by doping with a wide variety of electron acceptor molecules.
[0095] The same effects may be observed with aromatic or heterocyclic electron donor-type photoconductors when dispersed in non-photoconductive polymer and doped with electron acceptors. The reverse case is given when aromatic or heterocyclic electron acceptors are doped with small amounts (0.1-2 mole %) of electron donors and dispersed in a polymer. For example, photo-conductivity of films of poly-N-epoxypropylcarbazole (PEPC) doped with polymethine dyes (PD) with different iconicity, such as cationic (PD 1-3), squarylium (PD4), neutral (PD5), and anionic (PD6) can be exploited to built an organic photo-capacitor.
[0096] Polymethine dyes are used as sensitizers of photoconductivity and electroluminescence in photoconducting polymers based on their ability to convert light energy effectively and of the strong absorption and luminescence bands in a broad spectral region. The absorption maxima of films of PEPC with polymethine dyes are close to the respective wavelengths of light at 565 nm (PD1), 667 nm (PD2), 755 nm (PD3), 655 nm (PD4), 550 nm (PD5), and 560 nm (PD6).
[0097] The main advantages of the photocapacitor semiconductor device as described in various exemplary embodiments include the following:
[0098] (a) Light is used to control the photocapacitor, often advantageous over the varactor which uses voltage to control the capacitance. Electrical interconnects are thus not required. For example, avoidance of such connectors would benefit a radio frequency device, such as a split-ring resonator, in which wires could interfere with the radio frequency interaction.
[0099] (b) Design methods can be implemented in which harmonic generation in AC applications is minimized as opposed to the varactor device.
[0100] (c) New types of photo-electric applications are possible including, but not limited to, light-tunable electrical circuits that can be controlled with light tunable capacitance, new types of light detectors and arrays of detectors for light imaging, and new sensors where the sensitivity to light is secondary to a primary sensing method or detection method such as in the detection of biological or chemical agents.
[0101] (d) Tunable resonators for metamaterials, antennas, filters and other electromagnetic and/or electric devices, and interfaces or couplers between optical communication, optical computer components for standard solid state electronic systems.
[0102] (e) Devices that can be controlled using light (photocapacitance) and voltage (varactor) simultaneously.
[0103] (f) Wide dynamic range detectors.
[0104] (g) Detectors of which are difficult to saturate and/or damage with intense light.
[0105] (h) Photocapacitance devices that include one or multiple photocapacitors.
[0106] (i) A varactor can be used as a photocapacitor when combined with a photovoltaic device.
[0107] (j) A varactor can be used as a photocapacitor when combined with a photovoltaic polymer.
[0108] (k) Polymers that exhibit charge separation in response to light can be used as light tunable photocapacitors.
[0109] Note that a photocapacitor can be used with dual photocapacitance and varactor modes. The main advantages of controlling the fundamental initial state of the photocapacitor through type, energy location and density of traps include:
[0110] (l) Control of photocapacitor sensitivity and/or range by controlling the net thermal ionic charge through designed doping densities.
[0111] (m) Control of photocapacitor sensitivity and/or range by controlling the trap ionization level through designed choice of trap material.
[0112] (n) Control of photocapacitor sensitivity and/or range by using traps instead of recombination centers, or vise-versa.
[0113] (o) Control of photocapacitor sensitivity and/or range by utilizing multiple traps allowing control of electron generation and hole generation independently.
[0114] (p) Control of conductivity in regions of the photocapacitor associated with loss by controlling the net thermal ionic charge through designed doping densities.
[0115] (q) Control of conductivity in regions of the photocapacitor associated with loss by controlling the trap ionization level through designed choice of trap material.
[0116] (r) Control of conductivity in regions of the photocapacitor associated with loss by using traps instead of recombination centers, or vise-versa.
[0117] (s) Control of conductivity in regions of the photocapacitor associated with loss by utilizing multiple traps allowing control of electron generation/recombination and hole generation/recombination independently.
[0118] The main advantages of controlling the fundamental initial state of the photocapacitor through Fermi-energy control through the photocapacitor structure:
[0119] (t) Control of Fermi-energy position in the bulk photocapacitor material by appropriately choosing electron and/or hole traps and/or recombination centers.
[0120] (u) Control of Fermi-energy position in the bulk photocapacitor material by appropriately choosing shallow donors or acceptor states near the conduction band edge or valence band edge, respectively.
[0121] (w) Control of the Fermi-energy position at the junction using metals of different work functions.
[0122] (x) Control of the Fermi-energy position at the junction by using thin interfacial layers to reduce Fermi-energy pinning at the junction.
[0123] (y) Control of the Fermi-energy position at the junction by using another semiconductor to reduce Fermi-energy pinning.
[0124] (z) Control of the Fermi-energy position at the junction by using a semiconductor of the same type used for the photocapacitance material to reduce Fermi-energy pinning.
[0125] While certain features of the embodiments of the invention have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the embodiments. | A photocapacitor device is provided for responding to a photon having at least a specified energy. The photocapacitive device includes a first portion composed of a photocapacitive material; a second portion composed of a non-photocapacitive material; and a depletion region disposed between the first and second portions. The ph otocapacitive and non-photocapacitive materials respectively have first and second Fermi-energy differences, with the second Fermi-energy difference being higher than the first Fermi-energy difference. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of U.S. application Ser. No. 12/879,630 filed Sep. 10, 2010, the disclosure(s) of which is hereby incorporated in its entirety by reference herein.
TECHNICAL FIELD
[0002] The present disclosure relates to providing a desired cooling level in a liquid-to-air heat exchanger in an energy efficient manner.
BACKGROUND
[0003] In most production vehicles, the water pump that causes engine coolant to circulate through the engine and radiator is driven by the engine and the speed of the pump is dictated by the rotational speed of the engine. To ensure that there is sufficient coolant flow at the most demanding operating condition, the amount of flow at most operating conditions is higher than necessary. To improve control over the pump speed, the pump is decoupled from the engine and is either driven by an electric motor, driven by a variable speed clutch, hydraulically driven, or driven by some other actively controllable means. The electrically driven variant is particularly suited to a vehicle with a significant capacity for electrical power generation such as a hybrid electric vehicle.
[0004] It is common for a fan to be provided to direct air flow across the fins and tubes of the radiator. The fan is commonly electrically driven, although it too may be driven by a variable speed clutch, hydraulically driven, or driven by some other actively controllable means. The flow across the radiator is due to movement of the vehicle and the fan.
[0005] When an increase in heat transfer rate is indicated, the fan speed or the coolant pump speed may be increased.
SUMMARY
[0006] According to an embodiment of the disclosure, the choice of increasing the fan speed or increasing the pump speed is determined so that the power consumed is minimized. The broad concept is that dQ/dP, the gradient in heat transfer rate to power, is determined for both the fan and the pump at the present operating condition. The one with the higher gradient is the one that is commanded to increase speed.
[0007] A method to control cooling in a liquid-to-air heat exchanger with a fan and a pump forcing convection is disclosed including: determining a first gradient in heat transfer rate to fan power associated with adjusting fan speed, determining a second gradient in heat transfer rate to pump power associated with adjusting pump speed, and adjusting one of fan speed and pump speed based on the gradients. The method may further include determining whether a change in heat transfer is indicated and the adjusting one of fan speed and pump speed is further based on such change in heat transfer being indicated. The fan speed is increased when the first gradient is greater than the second gradient and an increase in heat transfer is indicated. The pump speed is increased when the second gradient is greater than the first gradient and an increase in heat transfer is indicated. The fan speed is decreased when the second gradient is greater than the first gradient and a decrease in heat transfer is indicated. The pump speed is decreased when the first gradient is greater than the second gradient and a decrease in heat transfer is indicated. The liquid is a coolant typically comprising water and ethylene glycol. The liquid is contained within a duct and the air may or may not be ducted. The liquid-to-air heat exchanger is called a radiator and the first and second gradients are determined by: evaluating a radiator performance relationship with radiator performance as a function of liquid coolant and air flows and/or velocities and transforming the radiator performance relationship into a heat transfer performance relationship with heat transfer rate as a function of liquid coolant and air flows and/or velocities. Radiator performance information may take one of several forms including: effectiveness, heat transfer per unit temperature difference between the bulk coolant and air flow streams entering the radiator, or any other suitable manner to capture performance. The performance relationships may be expressed as lookup tables, graphs, or empirical formulas. The first gradient is determined for increased fan speed and the second gradient is determined for increased pump speed when an increase in heat transfer is indicated. The first gradient is determined for decreased fan speed and the second gradient is determined for decreased pump speed when a decrease in heat transfer is indicated.
[0008] A method to control cooling in a liquid-to-air heat exchanger with a fan and a pump forcing convection is disclosed that includes determining a first gradient in heat transfer to power for increasing fan speed, determining a second gradient in heat transfer to power for increasing pump speed, increasing fan speed when the first gradient is greater than the second gradient, and increasing pump speed when the second gradient is greater than the first gradient. The method may further include determining whether an increase in heat transfer is desired. The choice of increasing fan speed and/or pump speed is further based on such a determination that an increase in heat transfer is desired. The first gradient is determined based on determining a gradient in heat transfer rate to air flow from a map of radiator performance and determining a gradient in air flow to fan power and the second gradient is determined based on determining a gradient in heat transfer rate to coolant flow from a map of radiator performance and determining a gradient in coolant flow to pump power.
[0009] A cooling system for an automotive engine includes a radiator coupled to an engine cooling circuit in which the engine is disposed, a fan forcing air past the radiator, a pump disposed in the cooling circuit, and an electronic control unit electronically coupled to the fan and the pump. The electronic control unit commands the fan and/or the pump to change operating speed when an adjustment in heat transfer rate is indicated. In some situations, the adjustment in heat transfer may be realized by increasing either the fan speed or the pump speed. The electronic control unit determines which of the fan and the pump to command based on a first gradient of heat transfer rate to power for adjusting fan speed and a second gradient of heat transfer rate to power for adjusting pump speed. The fan and the pump may be electrically driven, driven by a variable speed clutch, hydraulically driven, or driven by some other actively controllable means. The system may have various sensors and actuators coupled to the electronic control unit including: an ambient temperature sensor electronically coupled to the electronic control unit, an engine coolant sensor electronically coupled to the engine coolant circuit, and a vehicle speed sensor electronically coupled to the electronic control unit. The first and second gradients may further be based on inputs from the sensors which include the ambient temperature, the engine coolant temperature, and the vehicle speed.
[0010] The fan speed is commanded to increase when the first gradient is greater than the second gradient and an increase in heat transfer is indicated. The pump speed is commanded to increase when the second gradient is greater than the first gradient and an increase in heat transfer is indicated. The fan speed is commanded to decrease when the second gradient is greater than the first gradient and a decrease in heat transfer is indicated. The pump speed is commanded to decrease when the first gradient is greater than the second gradient and a decrease in heat transfer is indicated. The amount of the fan speed increase or decrease and the amount of the pump speed increase or decrease is based on an amount of a change in heat transfer rate that is indicated. In some situations, both fan and pump speeds may be increased simultaneously. These situations may include situations when increasing one or the other in isolation may not provide the desired increase in heat transfer performance. Further, in these situations, the aforementioned logic may be utilized to determine the speed increase for each actuator so as to realize the least combined usage of energy between them for increasing heat transfer by changing both fan and pump speed simultaneously.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic of an automotive coolant system;
[0012] FIG. 2 is a graph of radiator coolant flow and pump power as a function of pump speed;
[0013] FIG. 3 is a graph of radiator airflow and fan power as a function of fan speed;
[0014] FIGS. 4 and 5 are flowcharts according to embodiments of the present disclosure; and
[0015] FIG. 6 is a graph illustrating ranges at which fan or pump usage is preferred by performing a power analysis.
DETAILED DESCRIPTION
[0016] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0017] As those of ordinary skill in the art will understand, various features of the embodiments illustrated and described with reference to any one of the Figures may be combined with features illustrated in one or more other Figures to produce alternative embodiments that are not explicitly illustrated and described. The combinations of features illustrated provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations. Those of ordinary skill in the art may recognize similar applications or implementations consistent with the present disclosure, e.g., ones in which components are arranged in a slightly different order than shown in the embodiments in the Figures. Those of ordinary skill in the art will recognize that the teachings of the present disclosure may be applied to other applications or implementations.
[0018] According to an embodiment of the disclosure, the decision to increase the speed of a fan or a pump associated with a liquid-to-air heat exchanger is based on evaluating the gradient in heat transfer to power input, dQ/dP.
[0019] One example of a liquid-to-air heat exchanger to which the present disclosure applies is commonly called a radiator. Although the predominant heat transfer mode associated with the radiator is actually convection, it is commonly referred to as a radiator. For convenience and simplicity, the liquid-to-air heat exchanger is referred to as a radiator in the following description.
[0020] In FIG. 1 , a vehicle 10 having four wheels 12 , an internal combustion engine 14 , and a radiator 16 for providing cooling for engine 14 is shown. A liquid coolant, typically a mixture of water and ethylene glycol, is provided to a water jacket cast in engine 14 by a pump 18 . Typically, pump 18 is driven by engine 14 . However, in some applications, pump 18 is either electrically driven, driven by a variable speed clutch, hydraulically driven, or driven by some other actively controllable means so that pump 18 can be operated partially or fully independently of engine rotational speed. A fan 20 which is either electrically driven, driven by a variable speed clutch, hydraulically driven, or driven by some other actively controllable means is provided proximate radiator 16 . Air is forced across radiator 16 due to vehicle speed and/or fan 20 .
[0021] An electronic control unit (ECU) 30 is coupled to a variety of sensors and actuators, which may include, but is not limited to: ambient air temperature sensor 32 , engine coolant temperature sensor 34 , engine 14 , water pump 18 , fan 20 , vehicle speed sensor 36 , and other sensors and actuators 38 .
[0022] For a radiator having a particular architecture and deploying specific heat transfer media, a map of its heat transfer performance characteristics can be determined experimentally, analytically, or by a combination of the two. The resultant heat transfer performance map may take on the form of a dimensionless, heat-exchanger effectiveness. An example two-dimensional lookup table is shown in Table 1 in which the heat transfer media are engine coolant and air and the effectiveness is based on the flows and/or resultant velocities of the two heat transfer media:
[0000]
TABLE 1
Radiator Effectiveness
Airlow: Standard Air Velocity (m/s)
1.20
1.60
2.00
2.40
2.80
3.20
3.60
4.00
4.40
4.80
Coolant
0.50
0.826
0.765
0.710
0.660
0.616
0.577
0.542
0.511
0.483
0.458
flow
0.75
0.852
0.799
0.749
0.704
0.663
0.626
0.592
0.561
0.534
0.508
[kg/s]
1.00
0.866
0.818
0.772
0.729
0.690
0.654
0.621
0.592
0.564
0.539
1.25
0.875
0.830
0.786
0.746
0.708
0.673
0.641
0.612
0.585
0.560
1.50
0.881
0.838
0.797
0.757
0.721
0.687
0.656
0.627
0.600
0.576
1.75
0.900
0.863
0.827
0.792
0.758
0.726
0.696
0.668
0.642
0.618
2.00
0.911
0.879
0.847
0.816
0.786
0.757
0.729
0.703
0.678
0.655
2.25
0.918
0.890
0.861
0.833
0.805
0.778
0.752
0.728
0.704
0.682
2.50
0.923
0.898
0.871
0.845
0.819
0.794
0.770
0.747
0.725
0.703
2.75
0.927
0.903
0.879
0.855
0.830
0.807
0.784
0.762
0.740
0.720
[0023] The heat transfer rate is related to effectiveness:
[0000] Q=ε*C *ν*( T coolant,in −T air,in )
[0000] where Q is the heat transfer rate in W, c is the effectiveness, C is the heat capacity of the lower heat capacity fluid in J/kg-K, v is the mass flow rate of the lower heat capacity fluid in kg/s, T coolant,in is the temperature of engine coolant as it enters the radiator in K, and T air,in is the temperature of the air as it approaches the radiator in K. From the above equation, the heat transfer as a function of fluid flows can be computed and an example of which is shown in Table 2:
[0000]
TABLE 2
Heat Transfer in Watts
Airlow: Standard Air Velocity (m/s)
1.20
1.60
2.00
2.40
2.80
3.20
3.60
4.00
4.40
4.80
Coolant
0.50
10573
13058
15141
16900
18400
19694
20820
21803
22674
23451
flow
0.75
10907
13640
15992
18028
19803
21363
22740
23965
25062
26046
[kg/s]
1.00
11084
13957
16467
18668
20609
22332
23868
25249
26489
27617
1.25
11197
14160
16777
19090
21147
22984
24632
26119
27469
28692
1.50
11284
14305
16996
19392
21535
23458
25189
26759
28187
29490
1.75
11516
14737
17649
20275
22648
24799
26751
28525
30148
31635
2.00
11656
15008
18082
20895
23469
25833
27998
29992
31828
33523
2.25
11750
15190
18378
21324
24049
26566
28900
31058
33066
34931
2.50
11816
15320
18591
21639
24475
27119
29576
31873
34014
36016
2.75
11865
15419
18756
21880
24804
27542
30106
32504
34760
36871
[0024] In an automotive application, the air provided to the radiator may or may not be ducted and the temperature may be ambient temperature. In some applications, however, the temperature of the air is heated upstream of the radiator, i.e., it is exposed to other heat loads prior to being supplied to the radiator. In the automotive application, the velocity of the air blowing across the radiator is based on several factors including both the speed of the fan and the velocity of the vehicle. Temperatures may be inferred from provided engine sensors, such as engine coolant temperature and ambient temperature where applicable. Coolant velocity or mass flowrate is based on the pump speed and system architecture. Additional modeling may be required to account for the factors specific to the particular application and the particular present operating condition. The results of these models may be utilized in the ECU, or the models may themselves reside in the ECU and may be exercised in real time to provide the necessary information.
[0025] Next, gradients of heat transfer vs. fluid flow, dQ/dv can be determined for each of the fluids, as shown in Tables 3 and 4:
[0000]
TABLE 3
Gradient of Heat Transfer Versus Coolant Flow (Delta Heat
Transfer)/(Delta Coolant Flow in units of (W-s/kg)
Airlow: Standard Air Velocity (m/s)
1.20
1.60
2.00
2.40
2.80
3.20
3.60
4.00
4.40
4.80
Coolant
0.50
1336
2327
3404
4514
5613
6674
7677
8650
9552
10379
flow
0.75
711
1269
1902
2559
3224
3876
4514
5135
5705
6285
[kg/s]
1.00
450
812
1237
1689
2150
2607
3055
3480
3922
4299
1.25
348
580
879
1208
1552
1897
2226
2559
2871
3194
1.50
926
1726
2610
3531
4454
5364
6249
7063
7844
8578
1.75
563
1085
1732
2477
3284
4135
4990
5869
6718
7554
2.00
374
730
1186
1720
2317
2934
3608
4265
4954
5630
2.25
266
519
853
1259
1708
2211
2702
3259
3791
4340
2.50
194
396
657
962
1314
1692
2119
2525
2984
3419
2.50
194
396
657
962
1314
1692
2119
2525
2984
3419
2.75
Forward difference not available
[0000]
TABLE 4
Gradient of Heat Transfer Versus Air Flow (Delta Heat
Transfer)/(Delta Air Flow in units of (W-s/kg)
Airlow: Standard Air Velocity (m/s)
1.20
1.60
2.00
2.40
2.80
3.20
3.60
4.00
4.40
4.80
Coolant
0.50
6213
5208
4397
3750
3236
2815
2457
2178
1942
For-
flow
0.75
6833
5880
5091
4437
3899
3442
3064
2742
2459
ward
[kg/s]
1.00
7181
6276
5502
4853
4307
3841
3453
3099
2821
differ-
1.25
7407
6542
5784
5140
4592
4121
3718
3375
3057
ence not
1.50
7552
6728
5990
5356
4808
4327
3926
3570
3259
avail-
1.75
8052
7280
6566
5933
5376
4880
4435
4058
3717
able
2.00
8379
7685
7032
6437
5908
5414
4984
4589
4239
2 25
8602
7969
7366
6810
6294
5836
5394
5020
4662
2.50
8759
8178
7620
7091
6609
6143
5742
5353
5005
2.75
8885
8341
7810
7310
6845
6409
5996
5639
5277
[0026] The pump power and coolant flow are shown as a function of pump speed in FIG. 2 for a given set of vehicular operating conditions. Similarly, fan power and relative air flow rate are plotted as a function of fan speed in FIG. 3 for the same set of vehicular operating conditions. The data plotted in FIGS. 2 and 3 may be generating using models, may come from test data, or a combination of the two. In the case of airflow, the complicated influences of ram air and air side heat rejection may be included in the model. From the data in FIGS. 2 and 3 , a relationship between pump power vs. coolant flow (Table 4A) and a relationship between fan power vs. air flow (Table 5) can be determined:
[0000]
TABLE 4A
Radiator Coolant Flow as a Function of Pump Power
Coolant Flow (kg/s)
Pump Power (W)
0.50
31.8
0.75
84.5
1.00
167.7
1.25
287.4
1.50
452.2
1.75
675.6
2.00
980.9
2.25
1414.6
[0000]
TABLE 5
Air Flow as a Function of Fan Power
Air flow (m/s)
Fan Power (W)
2.40
47.1
2.80
174.1
3.20
352.7
3.60
587.1
4.00
889.5
4.40
1282.4
[0027] Based on the data in the tables above, gradients in coolant flow to pump power and air flow to fan power can be determined, as in Tables 6 and 7:
[0000]
TABLE 6
Gradient in coolant flow as a function of coolant flow.
(Delta Coolant Flow/
Coolant Flow
Delta Pump Power)
(kg/s)
(W-s/kg)
0.50
4.748E−03
0.75
3.003E−03
1.00
2.089E−03
1.25
1.517E−03
1.50
1.119E−03
1.75
8.188E−04
2.00
5.765E−04
2.25
NA
[0000]
TABLE 7
Gradient in air flow as a function of air flow.
(Delta Airflow/
Air Flow
Delta Fan Power)
(Std. m/s)
(W-s/kg)
2.40
3.150E−03
2.80
2.240E−03
3.20
1.706E−03
3.60
1.323E−03
4.00
1.018E−03
4.40
NA
[0028] At this point, dQ/dv and dv/dP are known for each fluid. From these, two values of dQ/dP, i.e., for coolant and air, can be determined. Examples of these tables are shown in Tables 8 and 9:
[0000]
TABLE 8
Gradient of Heat Transfer as a Function of Pump Power (W/W)
Airlow: Standard Air Velocity (m/s)
2.40
2.80
3.20
3.60
4.00
Coolant
0.50
21.43
26.65
31.69
36.45
41.06
flow
0.75
7.69
9.68
11.64
13.56
15.42
[kg/s]
1.00
3.53
4.49
5.45
6.38
7.27
1.25
1.83
2.36
2.88
3.38
3.88
1.50
3.95
4.98
6.00
6.99
7.90
1.75
2.03
2.69
3.39
4.09
4.81
2.00
0.99
1.34
1.69
2.08
2.46
[0000]
TABLE 9
Gradient of Heat Transfer as a Function of Fan Power (W/W).
Airlow: Standard Air Velocity (m/s)
2.40
2.80
3.20
3.60
4.00
Coolant
0.50
11.81
7.25
4.80
3.25
2.22
flow
0.75
13.98
8.73
5.87
4.05
2.79
[kg/s]
1.00
15.29
9.64
6.55
4.57
3.15
1.25
16.19
10.28
7.03
4.92
3.44
1.50
16.87
10.77
7.38
5.19
3.63
1.75
18.69
12.04
8.33
5.87
4.13
2.00
20.28
13.23
9.24
6.59
4.67
[0029] Based on the data in Tables 8 and 9, the more efficient device, fan or pump, can be commanded to increase output to respond to a demand for additional cooling. For example, if the present coolant flow is 1.25 kg/s and the present air velocity is 2.8 m/s, dQ/dP for the pump is 2.36 and for the fan, 10.28. In this example, the fan provides the greater heat transfer rate for the same input power.
[0030] The selection of which device to actuate to provide improved heat transfer is described above in terms of two-dimensional lookup tables. However, this is a non-limiting example. The determination can be based on data in graphical form, a set of empirical relationships of the data, a comprehensive model including all of the relevant factors, or any other suitable alternative. In regards to the above discussion, heat transfer leading to energy being removed from the coolant is considered to be positive and power supplied to the device (either fan or pump) is considered to be positive.
[0031] A flow chart showing both increases and decreases in heat transfer rate is shown in FIG. 5 and starts in 120 . Control passes to 122 in which it is determined if an increase or decrease in heat transfer rate is indicated. In one embodiment, only a heat transfer rate change exceeding a threshold level is enough to rise to the level of indicating a change in pump or fan speed. I.e., some hysteresis can be built in to avoid continuous changes in pump and/or fan speed. If the desired level of heat transfer change exceeds the threshold and it is determined in block 122 that an increase in heat transfer rate is warranted, control passes to block 124 to determine both values of dQ/dP. In embodiments where the liquid-to-air heat exchanger is a radiator, the values of dQ/dP may be determined by evaluating a radiator performance relationship with radiator performance as a function of liquid coolant and air flows and/or velocities and transforming the radiator performance relationship into a heat transfer performance relationship with heat transfer rate as a function of liquid coolant and air flows and/or velocities, as illustrated at block 125 . As the branch including blocks 124 , 126 , 128 , and 130 is the same as blocks 104 , 106 , 108 , and 110 , no further discussion of this branch is provided. If it is determined in block 122 that a decrease in heat transfer rate is warranted, control passes to 134 to determine both values of dQ/dP. The values of dQ/dP may, for example, be determined as illustrated in block 125 and discussed above. The two values are compared in block 136 . If dQ/dP for the pump is greater than dQ/dP for the fan, control passes to block 140 where fan speed is decreased. Otherwise control passes to block 138 in which pump speed is decreased. After any of the changes in fan or pump speed, i.e., in block 128 , 130 , 138 , or 140 , control passes back to block 122 .
[0032] The discussion above focuses on selecting the appropriate actuator to employ to meet a demand for additional cooling. It is also within the scope of the present disclosure to select the appropriate device to reduce heat transfer. In this case, dQ is negative and dP are negative because the rate of heat transfer is decreasing as well as the power input decreasing. In this situation, the device which has the lesser dQ/dP associated with it is the one that is commanded to reduce speed. The determination of the gradients dQ/dP for this situation can be determined analogously as for the situation where an increased heat transfer rate is indicated.
[0033] A flow chart showing both increases and decreases in heat transfer rate is shown in FIG. 5 and starts in 120 . Control passes to 122 in which it is determined if an increase or decrease in heat transfer rate is indicated. In one embodiment, only a heat transfer rate change exceeding a threshold level is enough to rise to the level of indicating a change in pump or fan speed. I.e., some hysteresis can be built in to avoid continuous changes in pump and/or fan speed. If the desired level of heat transfer change exceeds the threshold and it is determined in block 122 that an increase in heat transfer rate is warranted, control passes to block 124 to determine both values of dQ/dP. As the branch including blocks 124 , 126 , 128 , and 130 is the same as blocks 104 , 106 , 108 , and 110 , no further discussion of this branch is provided. If it is determined in block 122 that a decrease in heat transfer rate is warranted, control passes to 134 to determine both values of dQ/dP. The two values are compared in block 136 . If dQ/dP for the pump is greater than dQ/dP for the fan, control passes to block 140 where fan speed is decreased. Otherwise control passes to block 138 in which pump speed is decreased. After any of the changes in fan or pump speed, i.e., in block 128 , 130 , 138 , or 140 , control passes back to block 122 .
[0034] In the embodiment in FIG. 5 , a change in speed is commanded to one or the other of the pump and the fan. However, it is possible to determine a condition in which both are changed with the same constraint that the power increase is the minimum possible. If the computation interval is sufficiently short, the small changes in heat transfer to one or the other becomes essentially similar to combinations of changes to the two. Also, if the computation interval is short, the resulting changes in pump, or fan, speed are small steps.
[0035] The data in Tables 8 and 9 can be utilized to determine a region in which the gradient in dQ/dP is equal for the fan and the pump, shown as 150 in FIG. 6 . An increase in heat transfer is to be provided by the fan if the present operating condition falls above the line and to be provided by the pump if the present operating condition falls above the line. In operation, the algorithm will cause the operating condition to remain close to line 150 .
[0036] The tables above are shown for a specific arrangement and a specific set of operating conditions. The tables are updated continuously to reflect present conditions by a real time running model, results from such a model, test data, or a suitable combination. Also, in the above tables, coolant is provided as a mass flowrate and airflow as a velocity. However, any measure of flow can be used for either: mass flowrate, volumetric flowrate, velocity, as examples. As described herein, sensors may be used to provide input to models. However, there is a desire to minimize the sensor set to reduce cost. Thus, some of the quantities used in the models may be inferred based on sensor signals, actuator settings, or inferred from other sensor signals.
[0037] While the best mode has been described in detail, those familiar with the art will recognize various alternative designs and embodiments within the scope of the following claims. Where one or more embodiments have been described as providing advantages or being preferred over other embodiments and/or over background art in regard to one or more desired characteristics, one of ordinary skill in the art will recognize that compromises may be made among various features to achieve desired system attributes, which may depend on the specific application or implementation. These attributes include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. The embodiments described as being less desirable relative to other embodiments with respect to one or more characteristics are not outside the scope of the disclosure as claimed.
[0038] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments that may not be specifically illustrated or described. | An engine cooling system includes a liquid-to-air heat exchanger having an associated fan and a pump forcing convection and a controller communicating with the fan and the pump, the controller increasing fan speed in response to a first gradient in heat transfer rate to power exceeding a second gradient in heat transfer rate to power for increasing pump speed, and increasing pump speed when the second gradient is greater than the first gradient. The controller may increase the pump speed in response to a desired increase in heat transfer rate. The first gradient may be based on a gradient in heat transfer rate to air flow from a map of heat exchanger performance. The second gradient may be based on a gradient in heat transfer rate to coolant from a map of heat exchanger performance. | 5 |
RELATED APPLICATION
This application claims the benefit of the U.S. Provisional Application, Serial No. 60/164,890 filed Nov. 10, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
In general, the present invention relates to flexible packaging for chemicals, and more specifically, the present invention relates to flexible packaging for chemicals comprising multiple layers welded together to form a unique laminate capable of effectively containing the chemicals while maintaining chemical efficacy, stability and freshness.
2. State of the Prior Art
Typically, plastic containers are employed to store chemicals because the plastic containers enable the chemicals to possess an extended shelf life. That is, containment of the chemicals in plastic containers allows the chemicals to maintain chemical efficacy, stability and freshness. One such chemical commonly stored in plastic containers is sodium hypochlorite, more commonly referred to as, and including chlorine gas. Containment of these chemicals in plastic containers however, often times makes their use inconvenient and awkward. This increases the danger of exposure of the chemicals to the user. In addition, disposal of the plastic containers used to contain the chemicals, unless properly recycled, greatly increases the bulk in our countries landfills. With the vanishing number of landfills available and the inherent sanitary problems associated therewith, disposal of containers of this type represents a major health problem nationwide.
OBJECTS AND SUMMARY OF THE INVENTION
It is a general objective of the present invention to provide an improved flexible packet for housing chemicals employing multiple layers welded together to form a unique laminate.
It is a related objective of the present invention to provide a flexible packet for housing chemicals which enables the chemicals contained thereby to maintain chemical efficacy, stability and freshness.
It is another objective of the present invention to reduce the volume of waste deposited in landfills as a result of used chemical containers.
It is yet another objective of the present invention to provide a chemically pre-saturated towelette within the flexible packet to facilitate use of chemicals in the form of sanitizers and/or disinfectants.
Other objectives and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the description, like reference numerals refer to like parts.
In accordance with the foregoing objectives, and briefly stated, the present invention comprises flexible packaging for housing chemicals such as sanitizers and/or disinfectants utilizing multiple layers welded together to form a unique laminate. The invention enables maintenance of chemical efficacy, stability and freshness. Preferably, the present invention further comprises a chemically pre-saturated towelette housed in the unique flexible packaging to facilitate use of the chemical product.
BRIEF DESCRIPTION OF THE DRAWINGS
The organization and manner of operation of the invention, together with further objects and advantages thereof may best be understood by reference to the following descriptions taken in connection with the accompanying drawings, in which:
FIG. 1 illustrates the multi-layered flexible material employed to form the wall of the inventive packaging; and
FIG. 2 depicts a finished flexible packet of the present invention further illustrating a chemically pre-moistened towelette wipe contained thereby.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While the invention will be described in connection with a preferred embodiment thereof, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.
FIG. 1 illustrates a multi-layered laminate 8 utilized to form the wall of the soft, flexible packet for housing chemicals such as sanitizers and/or disinfectants. As shown therein, the laminate 8 contains an internal laminate layer 10 , an intermediate laminate layer 12 and an external laminate layer 14 . The internal laminate layer 10 is adjacent to one side of the intermediate laminate layer 12 and the external laminate layer 14 is adjacent to the opposite side of the intermediate laminate layer 12 . The specific configuration of the multi-layered laminate 8 is critical to ensure successful compatibility with the chemicals intended to be housed thereby. Sodium hypochlorite, a known liquid gas, i.e. chlorine gas, and quaternary ammonium chloride are two examples of chemicals which can be stored within the multi-layered laminate 8 of the present invention. The inherent properties of the sodium hypochlorite are such that the chlorine gas component thereof is responsible for the sanitizing and/or disinfecting capabilities of the chemical. Therefore the chemical packaging made from the multi-layered laminate 8 must not only be liquid impermeable, but must also be gas impermeable, thereby trapping the gas in the packet to maintain the effectiveness of the solution prior to usage thereof. If the chlorine gas were allowed to escape from the sodium hypochlorite solution, the chemical is rendered ineffective and incapable of performing its sanitizing and/or disinfecting function. The specific combination of the laminate layers illustrated enables the packaging to successfully house the chemicals and provide a satisfactory shelf life for same.
The layers of the inventive laminate 8 include a gas impermeable internal laminate layer 10 , a liquid impermeable intermediate laminate layer 12 and a protective and supportive external laminate layer 14 . In the preferred embodiment, the gas impermeable internal layer 10 is made from plastic, preferably plastic such as that sold under the trademark Surlyn®. Tiny holes, commonly referred to as “pin holes” are inherent in very thin layers of plastic. As the thickness or weight of the plastic is decreased, the presence of pinholes in the plastic increases. These pinholes allow the leakage of gas. Thus, it is important that the plastic internal laminate layer 10 be of sufficient thickness to retain gas within the internal laminate layer 10 . Preferably the internal laminate layer 10 is a 22 pound thickness. If the internal laminate layer 10 is not of sufficient thickness and therefore is not gas impermeable, the chemical may loose its efficacy as the gas escapes through the pin holes. For example, in the case of sodium hypochlorite, if the chlorine gas were allowed to escape, the chemical would no longer have the ability to disinfect or sanitize.
The intermediate laminate layer 12 is constructed from foil and provides a liquid barrier. In the preferred embodiment, the intermediate laminate layer 12 is made from foil which is approximately 0.0003 inches thick. In combination with the internal laminate layer 10 , this intermediate laminate layer 12 provides a liquid barrier for containing the chemical solution within the packaging. The intermediate laminate layer 12 also functions as an ultraviolet light retardant.
The external laminate layer 14 provides support and protection for the internal and intermediate layers 10 , 12 . The foil intermediate laminate layer 12 can be susceptible to folding or crinkling. When the foil folds, holes can result and the chemical solution can escape. The external laminate layer 14 provides a support upon which the foil intermediate laminate layer 12 rests so as to prevent folding or crinkling of the intermediate laminate layer 12 . This external laminate layer 14 must also be of sufficient thickness to provide support for the internal and intermediate laminate layers 10 , 12 . Preferably the external laminate layer 14 is 26 pound paper. The paper provides support for the intermediate layer 12 and at the same time provides flexibility allowing the internal and intermediate layers 10 , 12 to bend without allowing the foil to fold. Additionally, the external laminate layer 14 provides protection to the foil intermediate laminate layer 12 which can be fragile and may puncture easily when contacted by foreign bodies. If desired, the paper external laminate layer 14 can also be used for printing or labeling.
In the preferred embodiment, a coextrusion process is utilized to form the laminate layers 10 , 12 , 14 which are thereby welded together to form the multi-layered laminate 8 resulting in a Surlyn®/foil/paper combination. The welded combination allows for easier handling of the layers and simplifies construction of the packet. It is of course anticipated that formation of the packet as described below could be accomplished without first welding the laminate layers 10 , 12 , 14 together to form a combination. Through the use of the stated combinations of laminate layers or their equivalents, flexible packet storage of chemicals such as sodium hypochlorite and quaternary ammonium chloride becomes practical and effective.
Turning now to FIG. 2, a completed soft packet of the present invention is illustrated generally by reference numeral 16 . As shown therein, the packet 16 is formed preferably using a first package wall 22 and a second package wall 24 . Each package wall is formed from the laminate layers 10 , 12 , 14 . The package walls 22 , 24 are positioned so that the inner layer 10 of the first package wall 22 is adjacent to the inner layer 10 of the second package wall 24 . The package walls 22 , 24 are then welded together along a seam 18 to form the packet 16 having an internal cavity 26 . A chemical solution can be contained within the cavity 26 of the packet 16 once the seam 18 is completed to form the finished sealed packet 16 . As mentioned above, use of the chemicals contained by the packet 16 can be facilitated by use of a pre-saturated towelette 20 also contained by the packet 16 . The packet 16 illustrated in FIG. 2 is depicted in an open position on one side thereof to disclose the pre-moistened towelette 20 housed in the cavity 26 . It will be understood, however, that the finished product would include a welded seam 18 completely around the cavity 26 , for sale and storage purposes prior to usage. Alternatively, a single piece of laminate could be folded to create a first wall 22 and a second wall 24 , thus requiring a seam on only three sides of the walls 22 , 24 . Preferably the seam 18 is formed by simultaneously heating the perimeter of the laminate walls 22 , 24 to approximately 325-350 degrees Fahrenheit and compressing the laminate walls 22 , 24 together.
If a pre-saturated towelette 20 is contained within the cavity 26 of the packet 16 , the substrate of the towelette 20 must be inert or non-reactive with the chemical therein. If the towelette substrate 20 were to react with the chemical solution (e.g., sodium hypochlorite or quaternary ammonium chloride), the reaction would render the chemical inactive or ineffective for its intended use as a sanitizer and/or disinfectant. In the case of sodium hypochlorite, a known sanitizer at 200 PPM of free or available chlorine, and a known disinfectant at 5200 PPM, a substrate comprising a polyester or polyethylene structure will suffice. The towelette substrate 20 must be inorganic as opposed to organic, and thus inert so that it will not react with the chemical when housed in the packet 16 . If the towelette 20 caused sodium hypochlorite to react or expend its chemical energy/reaction when housed in the packet 16 , the residual solution would be salt and water and the chlorine component of the sodium hypochlorite would be exhausted and ineffective. Through use of the inventive packet 16 , laboratory studies have revealed that an extended shelf life of up to 18 to 24 months is possible for the chemicals contained thereby.
Again, the foregoing description is for purposes of illustration only and is not intended to limit the scope of protection accorded this invention. While preferred embodiments of the present invention are shown and described, it is envisioned that those skilled in the art may devise various modifications of the present invention without departing from the spirit and scope of the appended claims. | The present invention is directed to a flexible package for housing, chemicals such as sanitizers and/or disinfectants utilizing multiple layers welded together to form a unique laminate. The invention enables maintenance of chemical efficacy, stability and freshness. Preferably, the present invention further includes a towelette pre-saturated with the chemical housed in the unique flexible packaging to facilitate the use of the chemical product. | 1 |
BACKGROUND OF INVENTION
(a) Field of the Invention
The present invention relates to an improved emulsifying system and method for mixing accurate ratios of two or more liquids to form an emulsion. Preferably, but not exclusively, the liquids are water and oil which are pressure regulated and the supply is isolated from a vented storage container which stores the emulsion to feed emulsion burning apparatus.
(B) Description of Prior Art
There exists a need to provide efficient means of mixing water and oil together to form an emulsion to feed burning apparatus whereby to reduce pollutants which are released in the atmosphere and which also reduce the efficiency of burning apparatus and associated devices. Further, by providing a water/oil emulsion, less oil is consumed by the burning system. Various chemicals and apparatus have heretofore been provided in an attempt to achieve such objectives. However, such known methods and apparatus have not proved to be entirely efficient and economical.
Surfactants are sometimes used to break down the surface tension of one of the fluids to be mixed together, whereby to enable the mixing to take place. Surfactants are usually expensive and require additional savings in the system construction whereby to justify the cost thereof. Also, it has been found that surfactants promote boiler and flue corrosion. The very fact that the surface tension is reduced, eliminates or diminishes the microexplosions which take place with an emulsion produced without surfactants. These microexplosions are important to the improved performance of burning emulsion.
It is also known to use sonic whistles or similar type devices together with high pressure pumps to produce a desired emulsion. However, known systems which use such devices do not provide means to reduce capacity in order to correspond to varying firing rates of burners, without reducing feed pressures. The reduction of feed pressures seriously reduces the effectiveness of this type of equipment thereby providing a drawback.
Another type of apparatus known is the piston type homogenizer which is used to produce emulsions from water and oil. These homogenizers, however, require very large amounts of horsepower, require frequent maintenance, and are expensive.
Another type of prior art device known is the ultrasonic reactor which is used to produce a water/oil emulsion. This equipment is, however, very expensive, and uneconomical. Also, such reactors are known to fail due to overpressure, startup with cold oil, etc. This type of system is susceptible to damage from external pressure sources.
Controlling water to oil ratio is very difficult because there is a reliance on standard control items which in themselves are not accurate while trying to proportion through the range of firing rates of a burner system. Known methods and devices, such as those described above, are also very costly.
Recirculating or circulating emulsion through a burner system has been very difficult, if not impossible to achieve, because of the problem of contaminating the straight oil with emulsion.
SUMMARY OF INVENTION
It is, therefore, a feature of this invention to substantially overcome all of the above-mentioned disadvantages of the prior art and to provide an emulsifying system for mixing two or more liquids to form a stable emulsion.
A further feature of the present invention is to substantially eliminate the use of surfactants or any other chemical which is only used to produce such an emulsion.
A still further feature of the present invention is to provide a water/oil emulsion for burning and very accurately control the pressure of incoming fuel oil and water, always at one constant flow rate, to permit the control of very accurate proportions of the water and oil at any desired percentage, and at very reasonable cost.
A still further feature of the present invention is to store the emulsion in a container which is vented to atmosphere and totally isolate the output circuit from the high pressure supplies and to recirculate the emulsion to maintain it in a stable state and further to recirculate the emulsion through the burner system, in the same manner as the oil system is circulated without contaminating the straight oil with emulsion.
Another feature of the present invention is to produce an emulsion for feeding mixing devices such as ultrasonic reactors, or cells whereby to considerably increase the flow capacity therethrough to render such apparatus more economical.
According to the above features, from a broad aspect, the present invention provides an emulsifying system for mixing accurate ratios of two or more liquids to form an emulsion. The system comprises means for supplying an accurate mixture of the two or more liquids. Emulsifying means is provided to emulsify the mixture into an emulsion. Emulsion storage means is also provided for storing a quantity of the emulsion that may vary between predetermined limits. An output circuit draws the emulsion from the emulsion storage means. Emulsion storage means permits the supply of the mixture and the emulsion at a rate independent of the rate at which the emulsion is drawn from the output circuit.
According to a still further broad aspect of the present invention, there is provided a method of mixing accurate ratios of two or more liquids and forming a stable emulsion therefrom. The method comprises the steps of mixing the two or more liquids in an accurate proportion to form a mixture. An emulsion is then produced from the mixture. Emulsion is then stored in a storage means to permit the supply of the mixture and the emulsion to the storage means at a rate independent of the rate at which the emulsion is drawn from the storage means.
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of the emulsifying system; and
FIG. 2 is a sectional view of an example of the construction of an injector device.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, there is shown generally at 10, the emulsifying system of the present invention for mixing accurate ratios of water and oil taken from a water supply line 11 and an oil supply line 12, to form a water/oil emulsion for feeding burning apparatus (not shown) and fed at the emulsion output supply line 13. A pressure regulator 14, of simple and inexpensive design and of a type known in the art, is connected in the water supply line 11 to feed water under pressure to an injector device 15. Similarly, a back pressure regulator 16 is provided in the return line 17 which connects to the oil line 12 to also feed oil under pressure to the injector 15. This pressure regulator is also of the type well known in the art. The purpose of using a back pressure regulator is to maintain a constant oil pressure in the oil line 12 while at the same time permitting recirculation of oil. When the system 10 is in use, the bypass valve 18 automatically shuts off thereby automatically disconnecting the bypass line 19 from the emulsion output supply line 13.
A flow restriction means, herein a ratio adjustment valve 20, is connected in the supply line 11 downstream of the pressure regulator 14. A similar flow restriction means or ratio adjustment valve 21, is connected in the oil supply line 12 also downstream of the pressure regulator. These valves 20 and 21 are adjustable needle valves of the type well known in the art, and adjust the flow rates through the supply lines 11 and 12, respectively, to permit the proper ratio of water and oil to be fed to the inputs 22 and 23, respectively, of the injector 15. This ratio is normally of the order of up to one part of water to four parts of oil.
Referring now, more specifically, to FIG. 2, there is shown an example of how the injector 15 may be constructed. As hereinshown, the injector 15 consists of a simple T-shaped mixing device consisting of an outer tubular portion 24 and an inner tubular portion 25 having an outlet end portion 26 positioned concentrically within the outlet portion 27 of the outer tubular portion 24. The outlet end portion 26 is perforated as shown at 28 to permit water within the inner tubular portion 25 to be released in the outlet portion of the outer tubular portion 24 to mix with oil flowing within the outer tubular portion. This permits the water to be released in close contact with the oil whereby the water and oil particles will mix. As hereinabove mentioned, this is only an example of the construction of the injector and many other types of injector devices can be provided.
The water/oil emulsion or mixture at the outlet portion 27 of the injector 15 is fed to emulsifying means being a pressure pump 46 feeding a pressure mixer 48. The emulsion at the output of the mixer 48 is fed to a container 40. This container 40 constitutes a storage means for a quantity of the water/oil emulsion fed to it from the injector 15. The pressure in the container 40 is controlled, for example, by means of a vent 41 herein schematically illustrated. The container 40 is further provided with a recirculating circuit 42 which consists of an emulsion recirculating conduit 43 connected in a loop from an outlet 44, taken from the bottom of the container 40, to an inlet of the pressure pump 46. The pressure pump 46 is driven by a pump motor 47. The pressure mixer 48 takes the full pressure drop of the pressure pump 46 whereby to generate the emulsion. The outlet from the pressure mixer 48 is fed to the inlet 45 of the container 40.
The container 40 is provided with a volume control means which is constituted by a level float switch 54. Further, a temperature sensing device 51 may be provided to sense the temperature of the emulsion in the container to make sure it does not fall below a certain predetermined temperature. A heater element 52 may also be connected to the temperature sensing device to heat the emulsion when it falls below the predetermined temperature. The heater element 52 is controlled by the temperature sensing device 51.
When the level of the emulsion within the container 40 falls below a predetermined low level or exceeds a predetermined high level, a signal is given to a shut-off valve 53 located in the flow line connected to the output portion 27 of the injector 15. This signal will either cause the shut-off valve to open or close. Thus, the valve 53 is either in a fully open or a fully closed position. The level switch 54 may be connected directly to the shut-off valve 53. High and low level float switches 49 and 50 protect against excessive volume changes.
The shut-off valve 53 can also be of a slow opening or slow closing type, i.e., 4 or 5 seconds, in order to give the regulators time to lock up or seat themselves, depending on the type of regulators utilized. In the event that the regulating system were to consist of receivers or pans, then this valve may be of the fast opening fast closing solenoid type. The pressure pump 46 may also consist of any type of positive displacement pump such as a gear pump, triplex piston pump, which will give sufficient pressure for it to cause the desired effect when processing the fluids through the pressure mixer 48.
In the event that the recirculation of the emulsion causes the temperature to increase beyond the desired predetermined temperature, then coolers 55 may be provided in the recirculating conduit 43 to prevent the emulsion temperature from exceeding the predetermined desired temperature. Check valve 56 is provided in the conduit 43 to permit unidirectional flow of the emulsion. Also, the pressure in the line 43 may be monitored by the provision of a pressure gauge 56' downstream of the pressure pump 46.
It can be noted that with the above system, there is provided a storage of an emulsion which is maintained in a desired stable state and which is isolated from the pressure supplies. Such emulsion may be fed directly to burner apparatus (not shown) without subjecting such burner apparatus to pressures within the emulsifying system. In one application of the system as shown in FIG. 1, the outlet 44 of the container 40 may be connected to a mixer device 60 whereby the emulsion particles are further broken down to provide a finer mix before delivery to the burner device (not shown). As herein illustrated, for purpose of example only, the mixer device 60 is a high frequency mixer device capable of shattering water particles to obtain a finer emulsion. As previously described, an ultrasonic reactor cell may herein be provided and emulsion is fed into a cavity (not shown) incorporating an ultrasonic vibrator (not shown) to cause a breakdown of the emulsion particles. Shutoff valves 61 are provided on each side of the mixer device 60 to permit replacement of this mixer device by other suitable devices or to interconnect the valves 61 directly when such further mixer device 60 is not required. A check valve 62 insures unidirectional flow to the emulsion output supply line 13. As also shown in FIG. 1, a power supply 63 feeds the high frequency mixing device 60.
As further shown in FIG. 1, a bypass return line 64 from the burner device (not shown), is connected to the container 40. Coolers 65 may also be provided in the bypass return line 64 to regulate the temperature of the emulsion therein. Also, unidirectional valves 66 and 67 are provided, respectively, in the supply lines 11 and 12 to permit unidirectional flow. Oil pressure switch 68 and oil temperature limit switch 69 monitor the temperature and pressure of the oil within the oil supply line 12. Similarly, low pressure water limit switch 70 and percent water gauge 71 monitor the water supply line 11.
The pressure mixer 48 may have various type constructions. With the use of bunker "C" fuel oil, there is always the chance of dirt coming through the system and plugging orifices and consequently it may be advisable to use an orifice arrangement together with a pressure unloading valve which will discharge back to the inlet of the pressure pump 46 or possibly to the container 40 in the event that the orifice was to plug. On the other hand, a common ball-type relief valve, such as the type identified by the registered Trade Mark "NUPRO" may be used. In the event, of course, of any accumulation of dirt, then the ball in the valve would simply raise to clear itself. It may also be possible to use a simple chamber with various shape orifices or with an annular orifice, again using a pressure unloader or relief valve to prevent plugging. A still further alternative would be to use a sonic whistle of a type known in the art. Additionally, the efficiency of such whistle or any other device could be improved by modifying the discharge end to amplify the pressure fluctuations which theoretically should increase the performance.
The size of the container 40 may vary depending on the requirement of the application of the system. Various modifications of the system are seen without departing from the broad scope of the invention as defined by the appended claims.
The method of operation of this system can be summarized as follows. The water and oil supply lines are each provided with a pressure regulator whereby to supply water and oil to an injector device 15. The supply of the water and oil is regulated by ratio adjusting valves 20 and 21 respectively. The mix of water and oil at the outlet of the injector 15 is fed to a container 40 via a shut-off valve 53, and when the level of the emulsion 40 reaches a predetermined high level, the shut-off valve 53 is shut off, therefor isolating the pressure regulator supply lines from the container 40. The emulsion in the container 40 is recirculated through a recirculating circuit 42 and the emulsion is maintained in a stable state by a pressure mixer 48 which is fed by pressure pump 46 located in the emulsion recirculating circuit 42. The outlet of the container 40 is connected to burner apparatus (not shown) or to a further mixer device 60. As the emulsion is consumed, the level of the emulsion in the container 40 drops and when it reaches a predetermined low level, where it is necessary to replenish the container 40, the shut-off valve 53 is opened supplying more emulsion to the container 40. The size of the container 40 is selected to appropriately supply the burner device (not shown). It can be seen that whilst the container 40 is being supplied, the pressure from the water and oil supply lines will be vented through the container 40 as the check valve 56 will prevent any direct connection of these supply lines to the burner device (not shown) or the mixer device 60.
The emulsifying means, defined herein, could, for example, be an ultrasonic emulsifying device of a type known in the art similar to device 60. Also, as above-mentioned, the proportioning and mixing of the liquids can be effected in a variety of ways. It is also foreseen that this system could be utilized as an economical means of providing emulsions for uses other than for combustion, for example, in applications to the food and cosmetic industry.
It is further pointed out, that due to the improved combustion process resulting from the burning of the emulsion produced by the invention, particulate emissions is drastically reduced thereby making this invention a most important pollution control apparatus. Furthermore, there is achieved a great improvement of energy conservation. | An emulsifying system for mixing accurate ratios of two or more liquids to form an emulsion. The liquids are preferably, but not exclusively, water and oil. A supply circuit delivers accurate mixtures of the two or more liquids. An emulsifier emulsifies the mixture to form an emulsion. A container stores a quantity of the emulsion that may vary between predetermined limits and an output circuit is provided to draw the emulsion from the storage container. The emulsion storage container permits the supply of the mixture and the emulsion to the storage container at a rate independent of the rate at which the emulsion is drawn from the output circuit. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a discharge container with a nozzle for housing a liquid, for example, an instantaneous adhesive such as α-cyanoacrylate based adhesive or other moisture curing type adhesive, various adhesives such as solvent volatilizing type adhesive, various chemicals, foods, inks and medical supplies.
A liquid adhesive includes those of different types such as solvent volatilizing and moisture curing, of which the solvent volatilizing type adhesive cannot employ a plastic tube, and the moisture curing type adhesive also cannot employ a plastic tube through which moisture passes. For these reasons, these type adhesives have employed a metallic tube such as an aluminum tube and a lead tube.
Such a metallic tube is deformed and becomes poor in appearance with service, and particularly, the metallic tube cannot be stood up, so that each time the tube when not used is allowed to rest, its cap must be mounted to prevent contents from flowing out. In addition, there also exist problems that where the amount of contents is small, the metallic tube is small, so that it is difficult to handle, and that the metallic tube is difficult to use such that when its cap is opened or closed, for example, at the final step of service, an excessive force might be applied to the cap to cause the tube to be deformed or broken.
In order to solve these problems, the present inventors previously invented a composite container, as the one for a low-viscosity liquid, which comprises a body for housing contents, an internal container with a mouth for discharging the contents from the body, and an outer casing for covering the body of the internal container, and in which a pressure medium is interposed between the internal container and the outer casing (Japanese Patent Application No. HEI 4-198963).
Also, the present inventors previously invented a composite container employing a ratchet gear mechanism which prevents the cap from being strongly and threadly tightened with a force highter than a certain value, and the nozzle from being turned together with the cap when threadly untightened (Japanese Patent application No. HEI 4-348251).
Further, the present inventors invented a container with a nozzle and a cap, which container includes a nozzle connected to a container body for housing contents and a cap for closing the discharge mouth of the nozzle, as an improvement of a nozzle and a cap, and in which container the head of the cap is provided with an inwardly projected cylindrical member for closing the nozzle, and the head of the cylindrical member is provided with a concave hole into which or from which the tip of the nozzle is insertable or disengagable (Japanese Patent Application No. HEI 5-202811).
These prior inventions allow a liquid run to be positively prevented, the contents to be discharged completely, the container to be stood up, and the problem that a conventional container is difficult to use because of excessive tightening of cap, liquid leakage and the like to be solved.
However, these prior inventions have showed that they are preferably applied to contents of a relatively low viscosity liquid, and that for a liquid with a relatively high viscosity such as a highly thixotropic liquid, the so-called jelly-like liquid, particularly when the contents become less, an air layer is formed in the container body, whereby it becomes difficult to discharge the contents.
SUMMARY OF THE INVENTION
Research and study have been wholeheartedly made to develop a highly safe and easy-to-use container which can house a relatively high viscosity liquid such as jelly-like and grease-like ones, be stood up, discharge the contents completely, and provide no liquid run and leakage, and in which the tube when used is not deformed or broken, with the result that the present invention is finally obtained.
The present invention is a discharge container with a nozzle which comprises a container body for housing contents, a nozzle threadly attached to the container body, and a dual-shoulder type protective frame having a neck hole, and is characterized in that the base end of the mouth of the container body is inserted through the neck hole of the dual-shoulder type protective frame, and the container body is threadly attached to the nozzle, thereby allowing them to be made a one-piece structure.
An object of the present invention is to provide a highly safe and easy-to-use container which can be stood up, and provide no liquid run and leakage by interposing a dual-shoulder type protective frame having a neck hole between a container body and a nozzle when threadly attached to each other, by threadly attaching a cap to the nozzle as required, or by providing a bottom member for covering the container body to the dual-shoulder type protective frame.
Another invention of the present invention is a discharge container with a nozzle characterized in that in the above-mentioned container, one or more notch grooves or ribs are provided on the inner peripheral surface of the dual-shoulder type protective frame, while one or more ribs engaging with the above-mentioned notch grooves, or one or more notch grooves engaging with the above-mentioned ribs are provided on the base end of the mouth of the container body, thereby providing a structure for preventing a relative rotation of the container body to the dual-shoulder type protective frame.
Still another invention of the present invention is a discharge container with a nozzle and a cap characterized in that in the above-mentioned container, a boss having an outer ratchet gear corresponding to an inner ratchet gear formed on the inner periphery at the lower end of the above-mentioned nozzle is provided on the outer peripheral surface of the neck hole of the dual-shoulder type protective frame, or a boss having an inner ratchet gear corresponding to an outer ratchet gear formed on the outer periphery at the lower end of the above-mentioned nozzle is provided on the inner peripheral surface outside the neck hole of the dual-shoulder type protective frame, and that the container has a mechanism capable of preventing the cap from being strongly and threadly tightened with a force highter than a certain value, and the nozzle from being turned together with the cap when threadly untightened.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a front view to help explain one example of a discharge container with a nozzle of the present invention.
FIG. 2 is a perspective view of a state in which a cap is threadly attached.
FIGS. 3a-3c are a front view, a section view and a bottom plan view, respectively, of a dual-shoulder type protective frame with a neck hole.
FIGS. 4a-4c represent plan views and a side view of a dual-shoulder type protective frame with a neck hole.
FIG. 5 is a side view where a nozzle is mounted.
FIGS. 6a and 6b are illustrative views of a container body.
FIGS. 7a and 7b are a plan view and a bottom plan view of a nozzle.
FIGS. 8a-8c are a plan view and section views of a nozzle.
FIGS. 9a and 9b are a front view and a section view taken on line C--C.
FIGS. 10a and 10b are a section view and a bottom plan view of a cap.
FIGS. 11a and 11b are a plan view and a front view of a bottom member.
FIGS. 12a-12d are a front view, section views and a bottom plan view of a bottom member.
FIG. 13 is an illustrative view of an assembling procedure in manufacturing a discharge container with a nozzle of the present invention.
FIG. 14 is a view illustrating a discharging state.
FIG. 15 is a section view of a discharge container with a nozzle and a cap of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawings, the present invention will be explained in detail hereinafter.
FIG. 1 is a front view to help explain one example of a discharge container with a nozzle of the present invention, in which numeral 10 designates a container body, specifically an aluminum tube and the like; numeral 20 designates a nozzle screwed to the container body 10; and numeral 40 designates a dual-shoulder type protective frame with a neck hole, which covers partially the container body 10 as shown in the figure, preferably has a bottom member, and has a structure by which the container body can be stood.
Normally, a cap 30 is screwed to the above-mentioned nozzle 20, and FIG. 2 is a perspective view of a state in which the cap 30 is screwed.
Then, there will be sequentially explained the elements composing the present invention of the container body 10 for housing contents, the nozzle 20 screwed to the container body 10, the dual-shoulder type protective frame 40 with a neck hole and the cap 30 used as required, and the connecting relationship thereof, the modifications thereof and other aspects.
FIGS. 3 and 4 are views to help explain the dual-shoulder type protective frame 40 with a neck hole that the present invention features, in which FIG. 3-a is a front view; FIG. 3-b is a section view taken on line A--A thereof; and FIG. 3-c is a bottom plan view thereof. FIGS. 4-a and 4-c are plan views of the dual-shoulder type protective frame 40 with a neck hole 45; and FIG. 4-b is a side view thereof. In the above-mentioned views, there are mounted a bottom member, providing a structure capable of being stood.
The insertion of the container body 10 through the dual-shoulder type protective frame 40 is performed in such a manner that the mouth of the container body 10 is inserted through the neck hole 45 of the dual-shoulder type protective frame 40 as illustrated by the arrow of FIG. 3-a.
FIG. 5 is a side view where the mouth of the container body 10 is inserted through the neck hole 45 of the dual-shoulder type protective frame 40, to which mouth the nozzle 20 is mounted, and as apparent from the figure, the container body 10 can be urged in both the right and left directions.
FIG. 6 is one example of a container body, showing a case of an aluminum tube. FIG. 6-a is a plan view: and FIG. 6-b is a section view taken on line B--B thereof.
Normally, as shown in the figure, the mouth of the container body 10 is provided with a male screw 12 screwed thereto, and the base end thereof is protrusively provided with ribs 11, 11'. The ribs 11, 11' have a function such that they engage with one or more notch grooves, described later, provided on the inner peripheral surface of the neck hole of the dual-shoulder type protective frame, thereby preventing a relative rotation of the container body to the dual-shoulder type protective frame. Therefore, the number of the ribs and notch grooves in this case need be only capable of preventing a relative rotation of the container body to the dual-shoulder type protective frame, and though particularly there is no limitation in the number, the number of the ribs is usually one to twenty, preferably two to ten, six ribs being shown in the figure. The number of the notch grooves is one to 140, preferably 30 to 120, 72 notch grooves being shown in FIGS. 4-a and 4-c. When the number of both the above-mentioned ribs and notch grooves is too few, the degree of freedom is reduced, while when both is too many, generally the strength is reduced, so that a proper number is selected. Generally, as shown in the above-mentioned figures, it is preferable to make the number of the ribs rather few, and make that of the notch grooves rather many.
In this manner, a relative rotation of the container body to the dual-shoulder type protective frame need to be only prevented, so that the ribs and notch grooves can also be provided reversely to the above-mentioned manner such that the notch grooves are provided in the container body, while the ribs are provided on the dual-shoulder type protective frame. Also, it is obvious that the position at which the ribs are protrusively provided is not limited to a case where the ribs are provided on the neck of the tube as shown in FIG. 6-a, and a modification is also possible such as the one in which, for example, the ribs are protruded on the periphery of the shoulder of the tube.
FIGS. 7 and 8 are view showing one example of the nozzle 20 screwed to the container body referred to in the present invention, in which FIG. 7-a is a front view; FIG. 7-b is a bottom plan view; FIG. 8-a is a plan view; and FIGS. 8-b and 8-c are section views. As shown in the figures, the end base of the nozzle 20 is provided with a male screw 21 to which the cap 30, described later, is screwed, and a lower nozzle end 22 is formed with an inner ratchet gear 24 on the inner periphery thereof. The inner ratchet gear 24 is preferably provided with a plurality of slits 25, 25' dividing the gear in the peripheral direction as shown in the figure, thereby making the rotation smooth to achieve a smooth thread attaching. For a similar purpose, the skirt portion of the lower nozzle end 22 is provided with laterally cut slits 27 parallel to the circumferential direction (which are shown in a state that four laterally cut slits are provided in FIG. 7-b), thereby allowing a smooth rotation and thread attaching to be achieved.
The nozzle, as shown in the section views thereof (FIGS. 8-b and 8-c), is provided with a female screw 23 corresponding to the male screw 12 of FIG. 6, and by the thread attaching, the container is integrated with the nozzle.
FIGS. 9 and 10 are views showing one example of the cap 30 screwed to the nozzle referred to in the present invention, in which FIG. 9-a is a front view; FIG. 9-b is a section view taken on line C--C thereof; FIG. 10-a is a schematic section view thereof; and FIG. 10-b is a bottom plan view. As shown in the figures, in order to close completely the above-mentioned nozzle 20, a cylindrical member 31 protruding inwardly is provided to the cap 30, the head of which cylindrical member 31 is provided with a concave hole 32 into which or from which the tip of the above-mentioned nozzle 20 is insertable or disengagable. Provided inside the cap 30 are three or more ribs 35, 35' for introducing the nozzle, whereby the cap 30 can be smoothly engaged and disengaged. Further, as shown in FIG. 10-a, a gas leakage peak 36 is provided on the entire peripheral surface of the inner wall of the cap 30, thereby allowing the sealing ability of the cap 30 to be enhanced, and, for example, gas leakage and the like to be prevented and thus the sealing ability of the cap 30 to be further enhanced.
FIG. 13 is a view showing one example of an assembling procedure in manufacturing a discharge container with a nozzle of the present invention. As apparent from the illustrative description, the manufacture of a discharge container with a nozzle of the present invention is such that the cap 30 is screwed to the nozzle 20, while the mouth of the container body 10 is inserted through the neck hole 45 of the dual-shoulder type protective frame 40, and finally the bottom member is fitted into the frame 40, thereby providing an assembled product.
In using a discharge container with a nozzle of the present invention, the operation of the mouth opening and urging of the container body 10 is required. This operation is performed in such a manner that when the nozzle 20 is integrated with the dual-shoulder type protective frame 40 by threadly attaching the container body 10 to the nozzle 20, the protruded portion at the lower end of the nozzle 20 breaks through a closing film on the mouth of the container body 10 to open the mouth, whereby the container body 10 and the nozzle 20 communicate with each other, and an urging causes contents to be discharged from the nozzle 20. FIG. 14 is one example showing a state of discharging.
FIG. 15 is a section view showing the whole of a discharge container with a nozzle and a cap of the present invention, and showing a state in which the container body 10 and the nozzle 20 have communicated with each other.
Then, as shown in the above-mentioned FIGS. 3 and 4, the base end of the mouth of the container body 10 is inserted through the dual-shoulder type protective frame 40, and provided on the outer peripheral surface thereof is a boss formed with an outer ratchet gear 44 corresponding to the inner ratchet gear 24 formed on the inner periphery at the lower end of the above-mentioned nozzle 20. This provides a mechanism capable of preventing the cap 30 from being strongly and threadly tightened with a force highter than a certain value, and the nozzle 20 from being turned together with the cap 30 when threadly untightened.
Although the structure of the ratchet gear has been described above-mentioned in FIG. 4, in a case where provided on the outer peripheral surface of the neck hole 45 of the dual-shoulder type protective frame 40 is a boss formed with the outer ratchet gear 44 corresponding to the inner ratchet gear 24 formed on the inner periphery at the lower end of the above-mentioned nozzle 20, a modification may be possible in which as shown in FIG. 4-c, a boss formed with an inner ratchet gear 46 is provided on the inner peripheral surface outside the neck hole 45 of the dual-shoulder type protective frame 40, while as shown in FIG. 8-c, correspondingly thereto, an outer ratchet gear 26 formed on the outer periphery at the lower end of the nozzle 20 is provided so as to be used for a similar purpose.
A preferred embodiment of the dual-shoulder type protective frame having the neck hole that the present invention features is such that as shown in FIG. 3-a, the front thereof is substantially rectangular shape (formed of a line connecting sequentially points m, n, p and o in FIG. 3-a), and the side thereof is composed of two columns (X and Y). The reason the side is made columnar shape is that as described by the example of application in FIG. 14, the shape causes both the front and back to be opened to facilitate urging, and the reason the front view formed by the line connecting sequentially points m, n, p and o in FIG. 3-a is substantially rectangular shape is that when the contents in a metallic tube becomes less as the tube is actually used, the tube is deformed and finally becomes flat to widen the tube width, so that a space to accommodate the widened width is required. If such a space is not provided, the container body bumps against (becomes in contact with) the dual-shoulder type protective frame, so that it becomes difficult to discharge completely the contents from the container body. Therefore, it is obvious that a complete rectangular shape is not essential, and a space capable of housing the above-mentioned tube need to be only held. Also, it is obvious that as shown in FIG. 3-a, there is no trouble even when a greater importance is attached to the appearance to narrow somewhat the upper portion.
Further, a preferred embodiment of the present invention is such that as shown in FIG. 3-b, as for the shape of two colums (X and Y) to compose the side, the section thereof is formed in a manner to narrow as it goes inside. That is, in the figure, the distance between points g and h is made smaller than that between points e and f. This is because it is advantageous that although as urging the container body causes the contents to be discharged and thus becomes less, the thickness of the container body also becomes thin, as described above, the section is formed in a manner to narrow as it goes inside in order to squeeze completely the contents out.
Also, FIG. 3-c is a bottom plan view of the dual-shoulder type protective frame, and the bottom member is part of the dual-shoulder type protective frame in the present invention and has a function as an outer reinforcing casing supporting the container body. Therefore, although the shape and structure thereof are not particularly limited, various methods are considered for industrially producing the discharge container with a nozzle and a cap of the present invention.
Although the bottom plan view of the above-mentioned FIG. 3-c is in a state in which part of the bottom member is removed, and the member as it is can be stood, usually the bottom member is reinforced to produce a product. Alternatively, the bottom member is composed of one or more parts, which parts are sequentially assembled in a conveyor line process to produce a product.
FIGS. 11 and 12 are views showing one example of parts of the bottom member.
In the figures, FIG. 11-a is a plan view of parts of the bottom member; FIG. 11-b is a front view thereof; FIG. 12-a is a front view as viewed in the direction opposite to FIG. 11-b; FIG. 12-b is a section view taken on line D--D thereof; FIG. 12-c is a section view taken on line E--E thereof; and FIG. 12d is a bottom plan view thereof.
As shown in FIG. 13, it is preferable as an industrial manufacturing method that after the container body is inserted through, the parts of the bottom member are fitted into to achieve an integration.
In the discharge container with a nozzle of the present invention, a preferred embodiment is such that a bottom member 50 of the dual-shoulder type protective frame is provided with a mechanism for pushing up the container body 10 at all times. The mechanism can be operated by the resilience of a resin piece buried in the bottom member 50 of the dual-shoulder type protective frame. FIG. 11-b shows a case where the resilience of a resin piece is utilized, in which numeral 51 designates a resin piece buried in the bottom member. Instead of the resin piece 51, the mechanism may be also operated by the resilience of a spring buried in the bottom member.
The mechanism for pushing up the container body at all times is required in order to exhibit effectively the function of the discharge container with a nozzle of the present invention, and to make it easy to use safely the container.
Then, with respect to the material for the discharge container with a nozzle and a cap of the present invention, as described previously, the container employs a metallic tube, preferably an aluminum tube.
The material is a for the nozzle and cap used plastic material, which preferably includes polystyrene resin, polyolefin such as polyethylene, polypropylene, other polyester resin, polyamide resin, fluoroplastic and vinyl chloride resin.
With respect to the material for the dual-shoulder type protective frame having the neck hole, other than the above-mentioned resins, a relatively hard, synthetic resin is preferably used such as ABS resin, vinyl chloride resin, polycarbonate resin, polyacetal resin, styrene resin, urethane resin and hard rubber etc. As the other material, there can also be used metallic group such as aluminum, steel, brass and copper, and wood group. These materials are used so that it has the function of the protective frame when the container body is opened or closed, and also the function as the outer casing.
Although the discharge container with a nozzle or the discharge container with a nozzle and a cap of the present invention is applied preferably and particularly to a relatively high viscosity liquid such as jelly like one, the present invention is not only used for a high viscosity liquid, but also for a low viscosity liquid. In the latter case, in order to enhance a suck mechanism (the so-called squeezability) for preventing a liquid run from the nozzle during service, a cylindrical elastic material or an elastic tube with a flexibility may be wrapped or fittingly attached on the outer periphery of a container body, for example, a tube body of a metal such as aluminum; and an elastic material may be housed in the container body of metallic tube, and the resilience (elasticity) thereof may be also utilized to enhance the squeezability for preventing a liquid run, which are one of preferred embodiments of the present invention.
The container according to the present invention is a highly safe and easy-to-use one which can house a relatively high viscosity liquid such as jelly like and grease like ones, be stood, discharge the contents smoothly until before the last service, provide no liquid run and leakage, and discharge the contents completely until before the last service.
Particularly, the container of the present invention is very excellent in safety and operability such that the container is opened or closed through the protective frame without touching directly the container body, so that the tube when used is not deformed or broken until before the last service. Further, the discharge container with a nozzle and a cap of the present invention is very excellent such that it can be not only used for a high viscosity liquid, but also sufficiently for a low viscosity liquid by being modified somewhat as required.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | The present invention relates to an improvement of a discharge container with a nozzle for housing a liquid, for example, an instantaneous adhesive or another moisture curing type adhesive, various adhesives such as solvent volatilizing type adhesive, various chemicals, foods, inks and medical supplies. The present invention is a discharge container with a nozzle which includes a container body for housing contents, a nozzle threadly attached to the container body, and a dual-shoulder type protective frame having a neck hole, wherein the base end of the mouth of the container body is inserted through the neck hole of the dual-shoulder type protective frame, and the container body is threadly attached to the nozzle, thereby allowing them to be made a one-piece structure. The present invention is a highly safe and easy-to-use container which can house a relatively high viscosity liquid such as jelly-like and grease-like ones, be stood up, discharge the contents smoothly until before the last service, provide no liquid run and leakage, and discharge the contents completely until before the last service. Particularly, the container of the present invention is excellent in safety and operability such that the container is opened or closed through the protective frame without directly touching the container body, so that the tube when used is not deformed or broken until before the last service. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional application 60/644,831 filed Jan. 18, 2005.
BACKGROUND
[0002] Prepaid cards can provide an effective tool to promote the purchase of store merchandise. These cards are usually purchased with a selected value within a store and they are used to buy items in the store. Prepaid cards have particular usefulness in stores, such as coffee and donut shops, for the frequent purchase of food and beverage items being sold in these stores. Use of prepaid cards by a consumer can be advantageous to a merchant in that checkout times at the register can be reduced. Further, the purchase of these cards for a selected value, in effect, extends credit to a store until such time as the card is fully used.
[0003] From a marketing perspective, prepaid cards, can serve as vehicles to promote brand awareness and distribution. However, an existing challenge for merchants with prepaid cards concerns increasing prepaid card acceptance and use within the merchant establishment. For instance, it would be very desirous for a chain store to develop the use of its prepaid card and its brand identity to the extent and manner of that associated with some well-know credit cards. Some credit cards have been tied to symbols of status, identity or self-importance (e.g., gold cards, premium cards, etc). When certain credit cards are used for purchase, some view this event as the delivery of a symbolic message as well. However, use of prepaid cards in coffee and donut shops can present some unique problems in that frequent use of the prepaid card can also entail a certain amount of inconvenience in accessing the card from a wallet or purse.
[0004] A need exists to allow a consumer a means by which to conveniently access a prepaid card, encourage frequent use of a merchant's prepaid card and provide a merchant an opportunity to increase brand awareness so as encourage distribution of the prepaid card.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 a illustrates a side view of a fanciful beverage holder 2 having a lid, a handle and base.
[0006] FIG. 1 b illustrates a top view of a prepaid card inserted into a holder shown as a slot in a handle.
[0007] FIG. 1 c illustrates a top view of a prepaid card inserted into a holder shown as a slot in a base.
[0008] FIG. 2 illustrates a top view of a prepaid card which can include a magnetic stripe or bar code, for the purpose of being scanned by a register scanner, which is prominently displayed through slot on the beverage holder.
[0009] FIG. 3 a illustrates a side view of a fanciful beverage holder having lid, a base and grooved sides to facilitate a handgrip of the cup.
[0010] FIG. 3 b illustrates a top view of prepaid card inserted into a holder shown as a slot in a base.
[0011] FIG. 4 a illustrates a side view of a fanciful beverage holder having a lid, a handle 6 and a base.
[0012] FIG. 4 b illustrates a top view of a prepaid card inserted into a holder shown as a slot in handle.
[0013] FIG. 4 c illustrates a top view of prepaid card inserted into a holder shown as a slot in a base.
[0014] Applicable reference numerals have been carried forward.
DETAILED DESCRIPTION
[0015] The foregoing problems/needs are addressed by providing an article, which is commonly used in a store, that includes a holder compartment, slot, etc. for holding a prepaid card.
[0016] In one aspect of a preferred embodiment, the card is preferably exposed in its holder in order to readily accommodate electronic scanning.
[0017] In another aspect of a preferred embodiment, a beverage container is constructed so as to include a holder for a prepaid card.
[0018] In yet another aspect of a preferred embodiment the beverage container includes multiple locations thereon for the holder compartment for storage of the prepaid card.
[0019] FIG. 1 a illustrates a side view of beverage holder 2 having lid 4 , handle 6 and base 8 . Handle 6 and base 8 can include a slot 12 for insertion of a prepaid card. Beverage holder 2 is shaped with curved waist to facilitate a handgrip in addition to supporting a grip, by hand, of handle 6 . A brand or product name is preferably affixed or inscribed at any location on holder 2 as shown at space 11 .
[0020] FIG. 1 b illustrates a top view of a prepaid card 10 inserted into a holder shown as a slot 12 in handle 6 .
[0021] FIG. 1 c illustrates a top view of a prepaid card 10 inserted into a holder shown as a slot 12 in base 8 .
[0022] The prepaid cards shown in FIGS. 1 b and 1 c can be inserted into slots 12 such that the brand name of the merchant is prominently displayed.
[0023] In an alternative embodiment, card 10 can represent a prepaid care which includes a magnetic stripe or bar code (e.g a universal product code (UPC)), for being scanned by a register scanner such as a magnetic stripe reader or bar code reader, which is prominently displayed through slot 12 , as shown in the top view of card 10 , illustrated in FIG. 2 . Card 10 rather than being made in a similar fashion to an ordinary credit card, can include a magnetic stripe (or alternatively a bar code) on the face of the card rather than being on the back of the card on the side of the card opposite from the brand name display. Card 10 shown in FIG. 2 facilitates easy swiping of card 10 by a scanner (not shown) while serving a purpose of advertising by prominently displaying a merchant or product brand name.
[0024] FIG. 3 a illustrates a side view of beverage holder 20 having lid 4 , base 8 and grooved sides 22 to facilitate a hand grip of the cup. Base 8 can include a slot 12 for insertion of a prepaid card. A brand or product name is preferably affixed or inscribed at any location on holder 20 as shown at space 11 .
[0025] FIG. 3 b illustrates a top view of card 10 inserted into a holder shown as a slot 12 in base 8 .
[0026] Card 10 , which can be prepaid, is shown in FIG. 3 b as being inserted into slot 12 such that the brand name of the merchant is prominently displayed. Alternatively, card 10 as shown in FIG. 2 can be used for insertion into slot 12 so as to accommodate scanning while prominently advertising brand or product names.
[0027] FIG. 4 a illustrates a side view of beverage holder 30 having lid 4 , handle 6 and base 8 . Handle 6 , base 8 , can include a slot 12 for insertion of a prepaid card. Additionally, beverage holder 30 can include a clear sleeve 36 , preferably made of a clear polymer material, for insertion attached to the holder, located between lid 4 ands base 8 . Beverage holder 30 is shown with a smooth outer surface to accommodate the attachment of sleeve 36 thereto. A brand or product name is preferably affixed or inscribed at any location on holder 30 as shown at space 11 .
[0028] FIG. 4 b illustrates a top view of card 10 inserted into a holder shown as a slot 12 in handle 6 .
[0029] FIG. 4 c illustrates a top view of prepaid card 10 inserted into a holder shown as a slot 12 in base 8 .
[0030] The cards shown in FIGS. 4 a , 4 b and 4 c can represent prepaid cards and they can be inserted into respective slots 12 and sleeve 36 such that the brand name of the merchant is prominently displayed. Alternatively, card 10 as shown in FIG. 2 can be used for insertion into slot 12 so as to accommodate scanning while prominently advertising brand or product names.
[0031] In yet another embodiment, card 10 in FIG. 4 c can represent a flash memory. As media centers become more prevalent, downloading of content such as audio and video including music, news, etc. will become more common. Typically, media centers offer the opportunity for customers to access high speed Internet and to compile or burn CDs or for downloading into a digital device, e.g. Apple® iPod®. In one aspect, card 10 is a flash memory stick for insertion into sleeve 36 which is representative of pouch for carrying card 10 . The flash memory represented by card 10 is contemplated as having other shapes, e.g. sphere, bar, etc. that can be readily handled. As flash memory becomes cheaper, it is further contemplated that card 10 of suitably small enough capacity can be given away with a fee charged at the register for downloading music, videos, etc. Alternatively, promotions can be carried out using the memory stick of card 10 . For instance, one free download of music could be given away in a coffee shop for every purchase of 2 refills of coffee and a pastry.
[0032] The foregoing description supports a method of conducting business whereby prepaid cards, credit cards and the like are contained and prominently displayed within articles such as vessels (e.g., cups, glasses and the like), used within a particular business. The method of conducting business can also include the use of a prepaid card, debit card and the like which includes a magnetic stripe or bar code, for being scanned by a register scanner, which is prominently displayed through a slot, sleeve or the like. The prepaid card, credit card, etc., rather than being made in a similar fashion to an ordinary credit card, can include a magnetic stripe (or alternatively a bar code) on the face of the card rather than being on the back of the card on the side of the card opposite from the brand name display. Construction of the card in this manner facilitates the prominent display and easy storage of the card for use in article used in a particular business.
[0033] The business methods contemplated include using the cards in combination with beverage holders to carry out promotions. For instance, perhaps a free beverage refill can be secured upon using the card a number of times, e.g. five times.
[0034] It is calculated that the foregoing described invention in its various embodiments will create symbols of status, identity or self-importance through use of the card as used together with its holder. The shape of the beverage holder as described and shown herein can also serve to encourage this effect.
[0035] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. | A container is provided which includes a holder for a prepaid card, credit card, debit card and the like, for use in connection with purchasing products with a business establishment. | 1 |
FIELD OF INVENTION
[0001] The present invention relates to a dispensing device.
BACKGROUND OF INVENTION
[0002] Nitrogen is an essential nutrient in fertilizers and soils for the growth of pastures. Nitrogen is also a significant constituent in the urine of dairy cows and is therefore returned or recycled to pastures when cows urinate. Once an area of pasture is soaked in the urine of a cow, the nitrogen in the urine, most of which is present as urea, transforms very quickly into ammonium-nitrogen and then into nitrate-nitrogen which leaches out of the soil very quickly. In addition, much of the ammonium-nitrogen can be converted to greenhouse gases, ammonia and nitrous oxide. As a consequence of that, there is a huge loss of nitrogen from fertilizers in New Zealand, typically in the range of 20 - 100 kilograms per hectare annually.
[0003] A number of methods have been contemplated by biological scientists to minimise these losses of nitrogen. These methods include devices to spread the urine over a large area of the pasture, breeding cows with smaller bladders so that they urinate more frequently (and therefore over a larger total area), and producing grasses, clovers and other feeds that contain less nitrogen so that a smaller amount of nitrogen is consumed by cows. None of these methods has yet proved to be a practical method of overcoming the problem.
[0004] A feasible way of overcoming the problem is to spread an environmental friendly nitrification inhibitor, such as ammonium thiosulphate or a urease inhibitor on pastures. The main function of a nitrification inhibitor is to slow down the rate of transformation of ammonium-nitrogen to nitrate-nitrogen. A urease inhibitor reduces the rate at which urea converts to ammonium nitrogen. Either way pastures would have more time to absorb the nitrogen in the urine before the nitrogen is transformed to nitrate, which will then leach out of the soil very quickly. Although spreading a nitrification inhibitor on pastures is feasible in theory, the problem in practice is that it is not economical or practical to spread an inhibitor over large pasture areas. Clearly, the only efficient way of spreading such an inhibitor is to place it at locations where a cow has actually urinated, or a location where a cow is just about to urinate so that the inhibitor can act upon the nitrogen containing components of the urine. This in turn presents practical difficulties.
OBJECT OF THE INVENTION
[0005] It is an object of the present invention to provide a dispensing device or method which will at least go some way toward overcoming disadvantages associated with the prior art, or which will at least provide the public with a useful choice.
SUMMARY OF THE INVENTION
[0006] Accordingly in one aspect the present invention may broadly be said to consist in a dispensing device including
[0007] a reservoir means adapted and to contain a flowable substance;
[0008] an opening in the reservoir to allow the flowable substance to enter or exit the reservoir;
[0009] a valve means to allow the flowable substance to enter or exit the reservoir through the opening;
[0010] retention means to retain the device on an animal;
[0011] and the arrangement and construction being such that the valve means releases the flowable substance in response to the animal urinating or being likely to urinate.
[0012] In a further aspect the invention may broadly be set to consist in a method for dispensing a flowable substance in or adjacent to an area where an animal urinates or is likely to urinate, the method comprising the steps of
[0013] providing a reservoir containing a flowable substance,
[0014] attaching the reservoir to the animal,
[0015] sensing when an animal urinates or is likely to urinate, and
[0016] dispensing the flowable substance from the reservoir in or adjacent to the area where the animal has urinated or is likely to urinate.
[0017] The invention may also broadly be said to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of the said parts, elements or features, and where elements or features are mentioned herein and which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.
[0018] The invention consists of the forgoing and also envisages constructions of which the following gives examples.
DRAWING DESCRIPTION
[0019] One preferred form of the present invention will now be described with reference to the accompanying drawings in which;
[0020] [0020]FIG. 1 is a diagrammatic side view of a dispensing device in accordance with the present invention provided on the tail of a dairy cow with the tail in the lowered position.
[0021] [0021]FIG. 2 is a diagrammatic side elevation in cross section of the device of FIG. 1.
[0022] [0022]FIG. 3 is an end view of the device of FIG. 1.
[0023] [0023]FIG. 4 is a further side view of the device of FIG. 1 in use provided on a tail of a dairy cow with the tail in a raised position.
DETAILED DESCRIPTION
[0024] Referring to FIG. 1, a dispensing device in accordance with one embodiment of the present invention, generally referenced 1 is shown located about a tail 2 of a dairy cow 4 . The tail 2 is in a generally vertical or upright position and the device 1 is also in a generally upright position. Straps 6 are provided in use to secure the device 1 to the cow. It is also contemplated that the device may be secured to other parts of the body such as the back, abdomen or leg(s), or be secured to other apparatus which is fastened onto the cow 4 for example being attached to a form of saddle harness, or the like. The straps 6 could also be replaced with resilient or elastic members designed to hold the device in a desired position on the animal.
[0025] Referring now to FIG. 2, the dispensing device 1 is shown in more detail in a substantially horizontal position. The device 1 , at least in the presently preferred form, is shown in more detail includes an inlet 8 which has a stopper 9 that comprises a bung for example. A reservoir or enclosure 11 is provided having an outlet means 14 .
[0026] In the preferred embodiment the device 1 dispenses a liquid, since the substance intended to be dispensed by the device is often provided in liquid form, as described further below. However, it will be appreciated that the device could dispense other flowable substances, for example solids and powder, granular or sprayable form.
[0027] An aperture 10 is provided in the centre of the stopper 9 . A conduit 12 is received through the aperture 10 of the inlet 9 leading to the reservoir 11 . In use the stopper 9 may be removed to fill the reservoir 11 with a liquid or other flowable substance. The stopper 9 may be a simple bung that makes a frictional engagement with the walls surrounding inlet 8 , or could make a threaded engagement or be a “click fit” for example. The conduit 12 is provided to allow air to enter the reservoir 11 as the substance in the reservoir leaves the device through the outlet. This assists flow. Optionally, the conduit 12 may be used by a user to fill the liquid dispensing device. In use, chemical solutions that have urease or nitrification inhibiting properties, are placed in the reservoir 11 . Once the reservoir has been filled with a desired volume of the substance to be dispensed, the stopper 9 is then engaged with the walls of the reservoir adjacent to inlet 8 so that a seal is made between the stopper and the reservoir walls. It is also contemplated that other devices or designs such as a shutter or one way valve arrangement may also be used to allow solution and air to enter the inlet 8 but substantially prevent chemical solution from flowing but out of the inlet 8 .
[0028] The reservoir 11 is preferably of a shape adapted for location on a part of the tail of an animal such as a dairy cow, and defines an enclosure to contain the chemical solution. The end of the reservoir 11 opposite inlet 8 has annular outlet which is externally threaded at 18 so that it may be screwed onto an internal thread 20 of a valve housing 15 .
[0029] The housing 15 is also preferably annular in shape and consists of a front opening 19 with a threaded portion 20 at one end, an internal semi-spherical seat 22 designed for a ball-bearing to reside at the other closed end, and an annular channel intermediate section 24 . In use, the valve housing 15 is in fluid communication with the reservoir 11 . The valve housing 15 further includes an outlet spout 26 which extends from, and substantially perpendicular to the housing 15 . The exterior of the spout 26 is provided with upwardly wedging steps 28 to facilitate engagement with a flexible tube or the like if desired. A channel 29 is provided in the interior of the spout 26 opening to the interior of housing 15 adjacent to the valve seat 22 . Abutting a flat annular end surface 30 of the reservoir 12 is one end of a spring 32 . A ball-bearing 34 is provided at the other end of spring 32 . When the outlet means 14 is screwed endwise on to the reservoir means 12 , the spring 32 maintains a gentle force against the ball-bearing to prevent it from travelling too far away from the semi-spherical seat 22 when the device is in a substantially horizontal position. When the device is in a substantially vertical position, the ball-bearing stops the chemical solution from flowing out of the reservoir 11 by moving into contact with the seat 22 , thus blocking the channel 29 of the spout 26 .
[0030] Referring now to FIG. 3, an end view of the liquid dispensing device is shown. The body of the reservoir 12 is provided so as to be convex in shape to thus conform to the shape of the tail of the cow 4 as shown in FIG. 1. The reservoir 12 may be formed to various dimensions which are designed to contain a volume of chemical solution preferably in the range of 80-150 ml. Also, the device is preferably formed of a lightweight plastic so that the cow can raise its tail with ease and which enables the device to be manufactured easily and inexpensively. The spout 26 is preferably dimensioned, and the flow is preferably adjustable, to allow about 20 ml of chemical solution to flow out in 10 to 30 seconds, which is a typical urination period of a cow.
[0031] The preferred urease inhibitor for use with the present invention is a solution of the phosphoromide nBTPT (N-n-butyl) thiophosphoric triamide. The solution containing a concentrate of approximately 30% by weight of nBTPT has been found to provide satisfactory results with use of the dispensed volumes referred to above. It will be understood that other substitutes or alternative urease or nitrification inhibiting solutions may be used. Also, as mentioned previously, the inhibitor does not need to be provided in a liquid form as it could be provided in the form of pellets for example or granules. Although this would necessitate some changes to the preferred embodiment discussed herein, it will be understood to one skilled in the art that appropriate modifications could be made to the valve assembly of the apparatus to enable a granular substance to be released. Similarly, an inhibitor could be provided in a powder form which could be dispensed by spraying under pressure for example.
[0032] Turning now to FIG. 4, in use, the reservoir means 12 disposed in a substantially horizontal position is demonstrated when the tail 2 of the cow 4 is raised in a fashion to dispense the chemical solution from the spout 16 in the course of urination. Invariably, a cow will raise its tail to urinate. What happens is that the ball-bearing 34 will gently roll backwards towards the reservoir means 12 due to gravitational force, although its motion will be stopped at some stage by the spring 32 , which acts as a suspension and supporting device. The chemical solution will then be allowed to flow from the reservoir 11 through the valve housing 15 and through the spout 26 to fall on the pasture on or adjacent to the area where the cow urinates or is likely to urinate. After the cow 4 finishes urinating, its tail 2 will fall back to the original or ordinary position. Consequently, the ball bearing will restore to its seat 22 at the bottom end of the housing 15 , which will subsequently stop the chemical solution from flowing out of the spout 26 .
[0033] It will be seen that a number of different dispenser arrangements and valve arrangements may be used to implement the invention. In particular, the valve need not be limited to actuation by gravity i.e. there could be a level sensing device that senses the orientation of the tail of the animal and actuates the valve electrically, or pneumatically, or by some other means. Furthermore, rather than level sensing, the device may include a urine sensor i.e. a device which senses when urine flow is occurring, and actuates the valve accordingly. This may be necessary if the device is not attached to the tail of the animal. The device may also include a timer, for a timed valve actuation of predetermined duration.
[0034] It will also be seen that the invention is not limited to use with dairy animals. The invention is applicable to any situation where it is desirable to add a substance to the waste products of an animal.
[0035] As described above, one preferred solution that may be dispensed in accordance with the invention to reduce the rate of urea transformation is nBTPT, however other compositions or solutions may be used.
[0036] The reservoir is preferably made from a transparent plastic material so that the quantity of substance in the reservoir can be observed. It will be seen that the substance may be provided in any flowable form, and could be provided in the reservoir under pressure if desired.
[0037] The present invention envisages that a time-delay of say 5 seconds to be built in (either mechanically, electrically or pneumatically), so that no urease or nitrification inhibitor is dispensed (and therefore partially wasted), during the shorter-interval excreting activities of cows which usually also involve the animal raising its tail.
[0038] Several advantages over prior art are apparent. The importance of these advantages stem from the mobility and automation of the current invention. Firstly, since the liquid dispensing device is fastened onto a cow, it can function as a mobile dispenser where ever the cow goes. Secondly, as the liquid dispensing device is activated by the tail of the cow, no manual procedures or operations are required in the process of irrigating pastures except periodic refills with chemical solutions such as ammonium thiosulphate in the present case. Hence, although known watering cans can be used, there is no comparison to the convenience and portability offered by the current invention. Last but not least, consumption of the chemical solution can be reduced significantly by utilising the liquid dispensing device. The reason for this is because instead of having to apply the chemical solution all over a pasture or in specific patches, it can merely be applied locally to wherever the cow urinates. | A dispensing device including: A reservoir means ( 11 ) and to contain a flowable substance; An opening ( 19 ) in the reservoir to allow the flowable to enter or exit the reservoir ( 11 ); A valve means ( 15 ) to allow the flowable substance to enter or exit the reservoir ( 11 ); Retention means ( 6 ) to retain the device on an animal ( 4 ); and, The arrangement and construction being such that the valve means ( 15 ) releases the flowable substance in response to the animal ( 4 ) urinating or like to urinate. | 0 |
This application claims priority to U.S. Provisional Patent Application No. 61/110,263, filed Oct. 31, 2008, the contents of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
1. Background of the Invention
The present invention relates to a process for synthesizing higher diamondoids. More specifically, the process involves augmenting diamondoid molecules through the bonding of carbon atoms to smaller diamondoid species with intramolecular cross-linking to form larger diamondoids containing face-fused diamond-crystal (adamantane) cages with carbon frameworks superimposable on the cubic-diamond crystal lattice.
2. Description of Related Art
Although the structure of a molecule containing a cubic diamond crystal cage was first proposed by Decker in 1924, its synthesis proved extraordinarily difficult. The first successful synthesis of “adamantane” (the smallest diamondoid, containing only a single diamond crystal cage) was not achieved until 1941, and then with a yield of only 0.16%. In 1957, Schleyer discovered that adamantane can be formed in high yields from C 10 tricyclic intermediates by carbocation-mediated thermodynamically-controlled equilibration reactions. He used this method to also synthesize diamantane (a diamondoid containing two diamond crystal cages). An alternative name for diamantane is “congressane” because its synthesis had been posed as an exceedingly difficult challenge to chemists at the Nineteenth Congress of the International Union of Pure and Applied Chemistry.
The overall reaction of a strained C 14 H 20 polycyclic isomer, e.g., tetrahydrobisnor-S, to yield diamantane by the carbocation-mediated equilibration is in fact a staggeringly complex network of thousands of reaction pathways. Graphical analysis of the mechanisms for adamantane formation from endo-tetrahydrodicyclopentadiene shows an amazing 2897 different pathways (Whitlock, et al., 1968), many of the details of which have now been verified. Graphical analyses have also been performed for carbocation equilibration reactions leading to the diamondoids methyladamantane and diamantane. Limited analysis of the heptacyclooctadecane (triamantane) system suggests the existence of at least 300,000 intermediates.
The synthesis of triamantane by carbocation-mediated thermodynamically-controlled equilibration reactions was achieved in 1966. Since then, exhaustive research has established that higher diamondoids (diamondoids containing more than three face-fused diamond crystal cages) cannot be synthesized by the superacid-carbocation equilibration methods. Accordingly, a characteristic that distinguishes the lower diamondoids from the higher ones is that lower diamondoids can be synthesized by carbocation equilibration reactions while higher diamondoids can not. In fact only one of the higher diamondoids, [121]tetramantane, has ever been synthesized, and this by a complex, low-yielding, gas-phase double homologation of diamantane (Burns et al., J. Chem. Soc., Chem. Commun., 1976, pp. 893).
In 1980, the likelihood of the development of successful higher diamondoid syntheses was assessed and it was concluded that prospects were extremely unlikely because of a lack of large polycyclic precursors, increasing problems with rearranging intermediates becoming trapped in local energy minima, rising potential for disproportionation reactions leading to unwanted side products, and rapidly expanding numbers of isomers as carbon numbers of target higher diamondoid products increase (Osawa et al., 1980). With the failure to implement carbocation-mediated syntheses of higher diamondoids, attempts to synthesize higher diamondoids were largely abandoned in the 1980's.
Although attempts to synthesize higher diamondoids have up to now been unsuccessful, the thermodynamic stabilities of higher diamondoids are high relative to other hydrogenated carbon materials of comparable nanometer size.
Attempts to identify the presence of higher diamondoids in diamond products formed by a CO 2 -laser-induced gas-phase synthetic methods and diamond materials produced by commercial chemical vapor disposition (CVD) using methane as the carbon source have been unsuccessful. Unlike the synthetic chemical approaches discussed above which employ carbocation reaction mechanisms, these gas-phase diamond-forming processes involve free-radical reaction mechanisms (Butler et al., Thin Film Diamondoid Growth Mechanisms in Their Film Diamondoid , Lettington and Steeds Eds., London, Chapman & Hall, pp. 15-30, 1994). Thus, it previously appeared that no method for synthesizing higher diamondoids would be found.
Although they have never been synthesized, the existence of higher diamondoids in petroleum and their isolation for commercial applications has now been successful. However, a process for successfully synthesizing higher diamondoids would be of great value to the industry.
SUMMARY OF THE INVENTION
In some embodiments of the present invention, there is provided a method (or methods) for synthesizing higher diamondoid molecules. The method comprises sufficiently heating (or otherwise activating) diamondoid molecules having at least three cages so as to break carbon-carbon bonds to form small reactive carbon species, and then allowing a reaction to occur between these reactive species and diamondoid molecules having at least three cages to thereby add sufficient carbon atoms (that cross-link with dehydrogenation) to add at least one diamond crystal (adamantane) cage to such diamondoid molecules. The synthesized higher diamondoid molecules are then recovered. The heating can take place in a closed reactor, generally under an inert atmosphere, or the heating can take place in a chemical vapor deposition (CVD)-type chamber using a filament (or other excitation source) to create a concentration of reactive carbon species. Certain nondiamondoid carbon species, for example norbornane, isobutene, isobutane, can be added to the reaction mixture to promote the reaction, generating larger yields of higher diamondoids. Synthesized higher diamondoid molecules made via methods of the present invention are herein often referred to as “augmented higher diamondoids” or “synthetic higher diamondoids” (the terms are synonymous) to distinguish them from naturally-occurring higher diamondoids.
Among other factors and mechanisms, the present invention has discovered that higher diamondoids can be synthesized by employing free-radical reaction pathways. The reaction generally involves the addition of four carbons to a diamond face, controlled by steric effects such as those involving 1-3 diaxial interactions, thereby resulting in the formation of a new diamond crystal cage and the next larger diamondoid in the series (of progressively larger diamondoids). Particularly effective is the use of a gas phase reaction using the kinds of free radical reactions responsible for the growth of CVD-diamond. Smaller diamondoids act as seeds from which the next larger diamondoids are grown. Surface hydrogen atoms are removed and replaced by carbon-containing radicals generated from diamondoid starting material or certain added reactants, such as norborane. The process provides a method by which an effective synthesis of valuable nanomaterials (e.g., the higher diamondoids) can be achieved.
BRIEF DESCRIPTION OF FIGURES
FIG. 1 illustrates changing yields of tetramantane higher diamondoids from triamantane with changing reaction temperatures.
FIG. 2 illustrates the carbon framework structures of the four possible tetramantane higher diamondoids and where each is grown from specific faces of the triamantane starting molecules.
FIG. 3 illustrates the carbon framework structures of pentamantane higher diamondoids and which can be grown from [1(2)3]tetramantane.
FIG. 4 illustrates the carbon framework structures of pentamantane higher diamondoids and which can be grown from [121]tetramantane.
FIG. 5 illustrates the carbon framework structures of pentamantane higher diamondoids and which can be grown from [123]tetramantane.
FIG. 6 is a scanning electron micrograph (SEM) of diamond produced by chemical vapor deposition (CVD) nucleated by higher diamondoids.
FIG. 7 illustrates a side-view of a diamond growth reactor for producing higher diamondoids by a CVD process.
FIG. 8 illustrates a plan-view of a diamond growth reactor for producing higher diamondoids by a CVD process.
FIG. 9 represents a CVD free-radical reaction sequence in which higher diamondoids are formed from lower ones in addition to intermediate methylated precursors.
FIG. 10 illustrates CVD reaction steps in which sequential diamondoid radical formation/radical quenching with CVD-generated methyl radicals leads to formation of the next higher diamondoid species.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Higher diamondoids are nanometer-sized diamond molecules (containing 4 or more face-fused diamond crystal cages) having properties, such as negative-electron-affinity, that are valuable for commercial application in the microelectronics and other industries. Unlike the lower diamondoids (i.e., adamantane, diamantane and triamantane), higher diamondoids e.g., as discussed in U.S. Pat. Nos. 6,815,569; 6,843,851 ; 7,094,937; 6,812,370; 6,828,469; 6,831,202; 6,812,371; 7,034,194; 6,743,290, which are hereby incorporated by reference in their entirety, with the exception of one of the tetramantanes, have never been synthesized, despite intensive efforts to do so.
The present invention provides an effective and efficient method for synthesizing higher diamondoids. More specifically, it has been discovered that tetramantanes can be made from triamantane, that pentamantanes can be made from tetramantanes, and so on. In accordance with some embodiments of the present invention, the method involves the heating of diamondoid species (material) having at least three cages in a reactor. The reaction temperature is typically in the range of from 200-600° C. The reaction can be done with or without a catalyst, and is typically carried out under an inert atmosphere (at least initially). With a catalyst, reaction temperatures can be lower, e.g., preferably 275-475° C., more preferably 300-400° C., and most preferably 325-375° C. Without a catalyst, a higher temperature is employed, preferably in the range of 400-600° C., and more preferably in the range of 450-550° C.
Higher diamondoids can also be formed via gas-phase reactions employing the kinds of free-radical reactions responsible for the growth of CVD-diamond. In such processes, smaller diamondoids act as seeds from which the next larger diamondoids are grown. In such processes, surface hydrogen atoms are removed and replaced by carbon-containing radicals generated from diamondoid starting material and/or certain added reactants, such as isobutane. Four-carbon additions to a diamond face, at 1-3 diaxial sites formed via hydrogen abstractions, result in the formation of a new diamond crystal cage and the next larger diamondoid in the series.
Those of skill in the art will recognize that numerous variations exist on the above-described methods of the present invention, and that these variations are seen to fall within the scope of the instant invention, especially wherein they provide for augmented or synthetically-derived higher diamondoid species. Examples of such variations include, but are not limited to, reactant precursor composition and activation means (e.g., thermal, photolytic, and/or chemical) for providing reactant species.
In the examples below, diamondoid material is heated in a sealed, evacuated 316 stainless steel reaction vessel, and the presence and absence of a clay mineral (montmorillonite), with and without additional hydrocarbon reactants. A variety of reaction times and temperatures were employed and studied. After a given reaction was complete, the products were extracted and analyzed. Reaction products include alkylated forms of the starting diamondoid, smaller diamondoids, and valuable larger diamondoids. These examples are provided to demonstrate particular embodiments of the present invention. It should be appreciated by those of skill in the art that the methods disclosed in the examples which follow merely represent exemplary embodiments of the present invention. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments described and still obtain a like or similar result without departing from the spirit and scope of the present invention.
EXAMPLE 1
The first reactant was the lower diamondoid triamantane (C 18 H 24 ), isolated from petroleum and recrystallized 8-times to remove higher diamondoids. See, e.g., U.S. Pat. No. 7,173,160 for isolation of diamondoids from petroleum. Diamondoid impurities remaining in the starting materials after recrystallization were determined quantitatively by gas chromatography-mass spectrometry (GCMS) and referenced to the starting weight of triamantane reactant. [121]tetramantane, at a concentration of 10.5 ppm, was the only higher diamondoid detected in the recrystallized triamantane. The triamantane was loaded into the 316 stainless steel reaction vessel and montmorrilonite clay was added. The results of one series of reactions are shown in Table 1. This reaction series used identical conditions, except that a different hydrocarbon reactant was added to each reaction mixture. However, one experiment used triamantane without added hydrocarbons, i.e., neat. The objective was to study the possible reaction of triamantane with other compounds and with itself
TABLE 1 Yields of Individual Tetramantane Products from Triamantane Alone and with Various Added Reactants in the Presence of Montmorillonite Catalyst for 96 at 280° C. Reactants Triamantane Triamantane & Triamantane & Triamantane Triamantane & Products neat Adamantane Diamantane & Norbornane Norbornane [1(2)3]Tetramantane 2433 731 539 4365 4377 [121]Tetramantane 1176 407 318 1692 1333 [123]Tetramantane 880 32 30 201 123 (Yields are given as ppm of starting triamantane. 25 mg of triamantane and 25 mg of montmorillonite were used in each experiment).
Surprisingly, results listed in Table 1 show that most of the additional reactants inhibit rather than promote tetramantane formation. Triamantane alone generated tetramantane products, but yields dropped when adamantane or diamantane was added to the reaction mixture. Similar tetramantane product inhibition was found when hexane, 1,4-dimethylcyclohexane, bi-adamantane, bicylcoheptadiene, decaline or cubane was added. Only norborane improved yields of [1(2)3]tetramantane (by a factor of 1.8). However, yields of the other two tetramantanes fell relative to yields using only triamantane as the starting material.
TABLE 2
Yields of Individual Tetramantane Products from Triamantane
and Norborane Reactants in the Presence of Montmorillonite
Catalyst for 96 Hours at Various Temperature
Product
280° C.
280° C.
300° C.
350° C.
400° C.
450° C.
[1(2)3]Tetramantane
4365
4377
4132
5403
4026
2993
[121]Tetramantane
1692
1333
1640
2111
1379
401
[123]Tetramantane
201
123
211
173
72
9
(Yields are given as ppm of starting triamantane. 25 mg of triamantane, montmorillonite, and norborane were used in each experiment).
Table 2 lists results for a series of experiments, each run for 96 hours but at varying temperatures, the temperatures ranging from 280° C. up to 450° C. FIG. 1 is a plot of the data from Table 1 showing the yields of the three tetramantanes as a function of reaction temperature. A reaction temperature of approximately 350° C. gave the highest yields of tetramantanes under these conditions. The main products of the reactions are alkylated triamantanes. While not intending to be bound by theory, it is presumed that some of the triamantane in the reaction mixture cracks, thereby forming hydrocarbon radicals that can abstract hydrogen from intact triamantanes, forming stable alkyltriamantanes products. In addition to alkylated triamantanes, all three of the tetramantane higher diamondoids are formed.
EXAMPLE 2
In addition to triamantane, the three structural forms of tetramantane were also isolated and reactions were conducted with them to determine if any of the 6 stable, molecular weight (mw) 344, pentamantanes could be synthesized. Pentamantanes that are formed by the replacement of 3 tetramantane tri-axial hydrogens with a 4-carbon isobutane-shaped unit to form a new closed cage without breaking any of the original tetramantane carbon-carbon bonds—are highly favored. The most favored of these are those with the least steric hindrance associated with access to the tetramantane reactant face.
Table 3 presents results of experiments using [1(2)3]tetramantane as a starting material. The only possible pentamantanes that can be derived from the addition of 4 carbons to this tetramantane are [1(2,3)4]pentamantane, [12(1)3]pentamantane, and [12(3)4]pentamantane ( FIG. 3 ). In Table 3 it can be seen that two of these three pentamantanes were synthesized by the process. FIG. 3 illustrates the carbon frame-work structures of the six pentamantane higher diamondoids and indicates which can be grown from [1(2)3]tetramantane. Diamond crystal cages that can be added to [1(2)3]tetramantane are circled with dashed lines. Structures above the straight, horizontal dashed line in FIG. 3 are found in the reaction products, while structures below the line are not found, or found at trace levels. As measure of steric interference, Table 3 lists the number of 1,3-diaxial interactions associated with reactant faces from which specific pentamantanes could be formed by direct face-fusing of a diamond cage to [1(2)3]tetramantane. The data show that steric effects control which pentamantanes are formed from [1(2)3]tetramantane. Also shown in Table 3 are the number of ways in which a four carbon addition to a particular tetramantane will result in a particular pentamantane. This seems to be much less important than steric considerations.
TABLE 3
Production of Pentamantane Products from [1(2)3]Tetramantane 280°
C., Montmorillonite Catalyst, Reaction time = 96 hours
Pentamantane Yields and Characteristics
Number of
Number of 1,3-
Tetramantane
Specific
Diaxial
Reactant Faces
Specific
Pentamantane
Interactions on
That Can Form
Pentamantane
Products
Tetramantane
Specific
Products
(ppm)
Reactant Face
Pentamantane
[1(2,3)4]Pentamantane
7030
3
1
[12(1)3]Pentamantane
1417
6
6
[1212]Pentamantane
[1213]Pentamantane
[12(3)4]Pentamantane
12
3
[1234]Pentamantane
(Yields are given as ppm of starting material, [1(2)3]tetramantane. 9.0 mg of [1(2)3]tetramantane was used as starting material)
Even in this un-optimized reaction, the yield of valuable pyramidal [1(2,3)4]pentamantane is approaching 1 weight percent.
Table 4 presents results of experiments using [121]tetramantane as a starting material. In Table 4 it is seen that three of the six mw 344 pentamantanes were synthesized by the process.
TABLE 4
Production of Pentamantane Products from [121]Tetramantane 280°
C., Montmorillonite Catalyst, Reaction time = 96 hours
Pentamantane Yields and Characteristics
Number of
Number of 1,3-
Tetramantane
Specific
Diaxal
Reactant Faces
Specific
Pentamantane
Interactions on
That Can Form
Pentamantane
Products
Tetramantane
Specific
Products
(ppm)
Reactant Face
Pentamantane
[1(2,3)4]Pentamantane
[12(1)3]Pentamantane
655
6
4
[1212]Pentamantane
2965
3
2
[1213]Pentamantane
332
6
4
[12(3)4]Pentamantane
[1234]Pentamantane
(Yields are given as ppm of starting material, [121]tetramantane. 10.8 mg of [121]tetramantane was used as starting material)
As measure of steric interference, Table 4 lists the number of 1,3-diaxial interactions associated with reactant faces from which specific pentamantanes could be formed by direct face-fusing of a diamond cage to [121]tetramantane. FIG. 4 illustrates the carbon frame-work structures of the six pentamantane higher diamondoids and indicates which of these can be grown from [121]tetramantane. Diamond crystal cages that can be added to [121]tetramantane are circled with dashed lines. Structures above the straight, horizontal dashed line in FIG. 4 are found in the reaction products, while structures below the line are not found, or found at only trace levels. Again, the data show that steric effects control which pentamantanes are formed from [121]tetramantane, whereas the number of ways a specific pentamantane could be formed (Table 4) is not important. Even in this un-optimized reaction, the yield of valuable rod-shaped[1212]pentamantane is already ca. 0.3 weight percent.
TABLE 5
Production of Pentamantane Products from [123]Tetramantane 280°
C., Montmorillonite Catalyst, Reaction time = 96 hours
Pentamantane Yields and Characteristics
Number of
Number of 1,3-
Tetramantane
Specific
Diaxial
Reactant Faces
Specific
Pentamantane
Interactions on
That Can Form
Pentamantane
Products
Tetramantane
Specific
Products
(ppm)
Reactant Face
Pentamantane
[1(2,3)4]Pentamantane
[12(1)3]Pentamantane
5971
3
2
[1212]Pentamantane
[1213]Pentamantane
1403
3
2
[12(3)4]Pentamantane
5
2
[1234]Pentamantane
5
2
(Yields are given as ppm of starting material, [123]Tetramantane. 13.1 mg of [123]tetramantane was used as starting material)
Table 5 presents results of experiments using [123]tetramantane as a starting material. In Table 5 it is seen that two of the mw 344 pentamantanes were synthesized by the process. As measure of steric interference, Table 5 lists the number of 1,3-diaxial interactions associated with reactant faces from which specific pentamantanes could be formed by direct face-fusing of a diamond cage to [123]tetramantane. FIG. 5 illustrates the carbon frame-work structures of the six pentamantane higher diamondoids and indicates which can be grown from [123]tetramantane. Diamond crystal cages that can be added to [123]tetramantane are circled with dashed lines. Structures above the straight, horizontal dashed line in FIG. 5 are found in the reaction products, while structures below the line are not found, or found at trace levels. Again, the data show that steric effects control which pentamantanes are formed from [123]tetramantane, whereas the number of ways a specific pentamantane could be formed (Table 5) is not important. Even in this un-optimized reaction, the yield of valuable [12(1)3]pentamantane is already ca. 0.6 weight percent.
As stated previously, the pentamantanes that form experimentally from a particular tetramantane are the pentamantanes that can be formed by the addition of 4 carbons. Where the breaking of a tetramantane cage is required to form a particular pentamantane, that pentamantane will either not be generated from that particular tetramantane or it will be in very small relative amounts. The 4 carbons that are added take the form of isobutane and replace 3 tri-axial hydrogens on the tetramantane surface.
Starting with the linear [121]tetramantane, one can create a cage at the end of the molecule, extending the linear arrangement, to give the [1212]pentamantane. Alternatively, one could create a cage on the side of [121]tetramantane, which would give either [12(1)3] or [1213]pentamantane. One could not, however, form either [1(2,3)4], [12(3)4], or [1234]pentamantane without breaking cages and reconstructing the molecule. Interestingly, it is clear from Table 4 that the main products of reacting [121]tetramantane are [1212], [12(1)3] and [1213]pentamantane. Addition of the extra cage at one of the ends would involve the least steric hindrance, and this addition at the ends seems to be born out experimentally by the favored formation of [1212]pentamantane.
For [1(2)3]tetramantane, it is possible to put the isobutyl group on the top to form the pyramidal [1(2,3)4]pentamantane. Additionally, by completing cages along the sides of this tetramantane one can make [12(1)3] or [12(3)4]pentamantane. Table 3 shows that the predominant pentamantanes made by experimental pyrolysis of [1(2)3]tetramantane are in fact [1(2,3)4] or [12(1)3]pentamantane. Addition of the new cage to form [1(2,3)4]pentamantane would have the least steric hindrance and indeed [1(2,3)4]pentamantane is the predominant product. No [12(3)4]pentamantane was detected from the experiment and there was a slight amount of [1212]pentamantane, the latter of which would have had to have been formed by another mechanism.
Lastly, by adding an isobutyl to [123]tetramantane, one could theoretically make [1234], [12(3)4], [1213] and [12(1)3]pentamantane. Steric considerations would favor the formation of [12(1)3]pentamantane. Experimental data in Table 5 show that all of these pentamantanes are in fact formed, with [12(1)3]pentamantane predominating. No detectable [1(2,3)4]pentamantane was formed, and only trace amounts of [1212]pentamantane were seen, presumably formed by a different mechanism.
EXAMPLE 3
A series of experiments were performed to determine the importance of the montmorillonite clay in the synthesis of the higher diamondoids. Triamantane was sealed in an inert gold tube without montmorillonite catalyst and heated to 500° C. for 96 hours. Even without the montmorillonite the formation of higher diamondoids, both tetramantanes and pentamantanes was observed, as shown in Table 6. The reaction temperatures needed to be increased compared to the temperatures for reactions in the presence of montmorillonite, but yields were comparable. This result demonstrates that the montmorillonite is not essential for the higher diamondoid formation reaction.
TABLE 6
Production of Tetramantane and Pentamantane
Products from Triamantane without Catalyst
at 500° C., and with Isobutane or Isobutene
(at 500° C. without Catalyst)
Triamantane,
Triamantane
Triamantane
neat
& Isobutane
& Isobutene
[1(2)3]Tetramantane
1567
11413
16274
[121]Tetramantane
718
7163
8576
[123]Tetramantane
183
1304
1782
[1(2,3)4]Pentamantane
2
183
141
[12(1)3]Pentamantane
13
299
229
[1212]Pentamantane
5
182
137
[1213]Pentamantane
6
125
92
[12(3)4]Pentamantane
0.9
8
9
[1234]Pentamantane
0.4
Reaction time = 96 hours. Yields are given as ppm of starting material, triamanatane. Reactants were sealed in evacuated gold tubes.
Because each diamondoid cage closure requires four carbons in an isobutyl configuration, isobutane and isobutene were added to the reaction as carbon sources for the additional higher diamondoid cages. Table 6 shows that yields of higher diamondoids can be greatly increased by the addition of either isobutene or isobutane to the reaction mixture.
TABLE 7
Production of pentamantane products from [121]tetramantane
Reactants
[121]Tetramantane
[121]Tetramantane
[121]Tetramantane
& Isobutane
& Isobutene
Products
(ppm)
(ppm)
(ppm)
[1(2,3)4]Pentamantane
[12(1)3]Pentamantane
104
2922
1005
[1212]Pentamantane
114
7637
1970
[1213]Pentamantane
34
2634
617
[12(3)4]Pentamantane
[1234]Pentamantane
* Neat with isobutane or isobutene at 500° C. under argon in sealed gold tube
{circumflex over ( )} Neat at 500° C. under argon in sealed gold tube
TABLE 8
Production of pentamantane products from [1(2)3]tetramantane
Reactants
[1(2)3]Tetramantane
[1(2)3]Tetramantane
[1(2)3]Tetramantane
& Isobutane
& Isobutene
Products
(ppm)
(ppm)
(ppm)
[1(2,3)4]Pentamantane
1723
2995
1341
[12(1)3]Pentamantane
332
2552
872
[1212]Pentamantane
62
21
[1213]Pentamantane
79
6
[12(3)4]Pentamantane
62
11
[1234]Pentamantane
* Neat with isobutane or isobutene at 500° C. under argon in sealed gold tube
{circumflex over ( )} Neat at 500° C. under argon in sealed gold tube
TABLE 9 Production of pentamantane products from [123]tetramantane Reactants [123]Tetramantane [123]Tetramantane [123]Tetramantane & Isobutane & Isobutene Products (ppm) (ppm) (ppm) [1(2,3)4]Pentamantane [12(1)3]Pentamantane 497 5886 1116 [1212]Pentamantane 214 231 37 [1213]Pentamantane 41 3318 613 [12(3)4]Pentamantane 39 462 60 [1234]Pentamantane 638 97 * Neat with isobutane or isobutene at 500° C. under argon in sealed gold tube {circumflex over ( )} Neat at 500° C. under argon in sealed gold tube
Similar runs, without any catalyst, where run to test conversion of individual tetramantane higher diamondoids into pentamantane higher diamondoids. Table 7 shows results using neat [121]tetramantane neat, with isobutene or isobutene, sealed in a gold tube under argon atmosphere and heated to 500° C. for 96 hours. Table 8 shows results using neat [1(2)3]tetramantane neat, with isobutene or isobutene, sealed in a gold tube under argon atmosphere and heated to 500° C. for 96 hours. Table 9 shows results using neat [123]tetramantane neat, with isobutene or isobutene, sealed in a gold tube under argon atmosphere and heated to 500° C. for 96 hours. These results further demonstrate that the montmorillonite is not essential for the higher diamondoid formation reaction and that yields of higher diamondoids can be greatly increased by the addition of either isobutene or isobutane to the reaction mixture.
It is clear from the experiments above (Examples 1-3) that diamondoids are being “built up” by the addition of carbons, some replacing hydrogens to complete a cage or cages and form larger diamondoids. This mechanism is analogous to the growth of chemical vapor deposition (CVD) diamond. CVD diamond is typically grown in a very reducing hydrogen atmosphere (typically over 90%), much of it in atomic form to keep carbon-carbon double bonds from forming. Diamond growth is derived from the addition of methyl and/or ethyl radicals replacing hydrogen on the surface of small diamond seeds which are necessary for initiation of the process. In this way, new cages are formed and the size of the diamond increased. This process takes place at fairly high temperatures, generally in excess of 450° C.; however, pressures are low, usually near atmospheric. Conditions are much less optimal for higher diamondoid growth in natural gas fields, but the time frames are considerable, with oil generation and oil cracking taking place on the order of millions of years or more. This leads to the conclusion that if conditions were optimal, i.e., conditions used to grow CVD diamond, that it would be possible to effectively synthesize higher diamondoids and larger nanodiamondoids of a particular size range using lower diamondoids as seeds.
FIG. 6 is a scanning electron micrograph (SEM) of diamond produced by chemical vapor deposition (CVD) nucleated using alkyltetramantane higher diamondoids. This shows that diamondoids like the tetramantanes can act as seeds from which larger diamond crystals can be grown. The key is to identify conditions that stop the growth of the crystals growing from the diamondoid seed while particle sizes are still in the 1 to 2 nanometer size range.
These experimental conditions are less than ideal for growing CVD diamond (they were designed to mimic petroleum formation and oil cracking), yet they generated higher diamondoids with a yield of about 1%. Based on these results, if conditions are optimized in the CVD chamber small diamondoids seeds will readily grow larger diamondoids in the vapor phase. One could start with adamantane, diamantane or triamantane, which are readily available either through synthesis or isolation from petroleum. Having a relatively high vapor pressure at CVD diamond growth temperatures, these could then be put into a CVD chamber in the vapor phase to act as nucleation sites for diamond growth. By adjusting the conditions appropriately (time, temperature, gas composition including hydrogen and carbon source) tetramantanes, pentamantanes, hexamantanes, etc. can be grown in the gas phase. As the diamondoids grow larger, they precipitate from the vapor as their vapor pressure decreased. A cooler, collector substrate collects these larger diamondoids. If still larger diamondoids are desired, heating or mechanical agitation of the collector substrate keeps the diamondoids in the growth environment as long as desired. By this means, larger diamondoids/diamonds, e.g. diamondoids with ca. 100 carbons which could be used for photonic crystals and for catalysts will form. Furthermore, by beginning with a derivitized diamondoid, e.g., derivitized with an amine or borane group, one can effectively dope the larger diamondoids being grown with nitrogen or boron. Alternatively, one can derivitize and/or dope the diamondoid with functional groups by addition of appropriate reactants in the CVD chamber.
CVD growth of diamonds is believed to occur on a heated substrate via hydrogen extraction and hydrogen and carbon containing radical attachment mechanisms. Diamondoids with a sufficient number of internal degrees of freedom should act in the same way as the small diamond seed crystals used to nucleate conventional CVD diamond growth. A detailed description of this process can be found in the book Physics and Applications of CVD Diamond , Satoshi Koizumi; Christoph Nebel, Milos Nesladek, John Wiley and Sons, 2008.
A modification of a traditional hot-filament reactor designed for growing higher diamondoids is shown in FIGS. 7 and 8 . A vacuum chamber maintained at a pressure of approximately 1 Torr is filled with hydrogen (ca. 99%) and a carbon containing gas (e.g., CH 4 ca. 1%). The filament is heated to approximately 2000K to dissociate the hydrogen, thereby providing a source of atomic hydrogen. The diamondoid gas is supplied by a tube through the radiation shields. The collector substrate is placed within the radiation shield, and maintained at a temperature too low to produce diamond growth reactions. The temperature gradient between the filament and the collector substrate provides a range of conditions suitable to cause growth on the diamondoid surfaces. Growth rate and efficiency can be optimized by changing geometry and gas composition in the reactor. Formation of diamondoids of increasing diamond crystal-cage count by this CVD system is illustrated in FIGS. 9 and 10 . Hydrogen radicals (atoms) generated from hydrogen gas in the CVD chamber strip hydrogen atoms from diamondoid seed molecules, generating diamondoid free radicals that add carbon atoms by quenching with methyl radicals formed from methane in the CVD plasma. Methylated diamondoids are major products leading to subsequent ring/cage closure and formation of the next higher diamondoid with a cage count of N+1, where N is the number of diamond crystal cages in the seed diamondoid. FIG. 10 shows an example reaction sequence in the formation of [1(2)3]tetramantane from triamantane in the CVD chamber. Hydrogen atoms are stripped from a seed diamondoid face giving rise to a radical that is quenched by a methyl radical producing a methylated intermediate. Sequential 1, 3, 6 addition of methyl radicals by this mechanism generates the corresponding trimethyltrimantane in which the [1(2)3]tetramantane is formed by carbon radical addition, hydrogen abstraction, and ring/cage closure. This sequence can also form pentamantanes from tetramantanes, hexamantanes from pentamantanes, heptamantanes from hexamantanes, and so on.
All patents and publications referenced herein are hereby incorporated by reference to an extent not inconsistent herewith. It will be understood that certain of the above-described structures, functions, and operations of the above-described embodiments are not necessary to practice the present invention and are included in the description simply for completeness of an exemplary embodiment or embodiments. In addition, it will be understood that specific structures, functions, and operations set forth in the above-described referenced patents and publications can be practiced in conjunction with the present invention, but they are not essential to its practice. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without actually departing from the spirit and scope of the present invention as defined by the appended claims. | In some embodiments, the present invention is directed to methods for synthesizing higher diamondoids, wherein said methods involve augmenting existing diamondoid molecules through the bonding of carbon atoms to such existing diamondoid species with intramolecular cross-linking so as to form larger diamondoids containing face-fused diamond-crystal (adamantane) cages with carbon frameworks superimposable on the cubic-diamond crystal lattice. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed generally to an apparatus and method for sound generation on a bicycle.
2. Description of the Related Art
Many readers will recall childhood memories of attaching a baseball card to a bicycle frame using a clothespin to create a flapping “motorcycle” sound as the baseball card is struck by the spokes of the rotating bicycle wheel. While such an approach was inexpensive, the baseball card would soon wear out or become bent so as to fail to produce the desired sound. In addition, if the baseball card became wet, it was no longer able to produce the desired sound.
Since that time, others have attempted various forms of bicycle sound generators. Some are directed to attachment mechanisms that are expensive to manufacture, difficult to install, and may damage the paint finish on the bicycle. For example, one known approach comprises a bicycle sound generator made of stiff plastic. This type of generator includes a flap portion to extend into and engage the spokes of the bicycle and a preformed attachment mechanism with a partially cylindrical interior portion to clip over a rounded bicycle fork. A gap along the length of the cylindrical plastic attachment mechanism allows the sound generator to be snapped onto a round bicycle fork. The drawback of this approach is that the cylindrical-shaped attachment mechanism is only useable with a round bicycle fork. Bicycle forks commonly have an oval cross section fork, which is incompatible with the cylindrical attachment mechanism of the known bicycle sound generator. In addition, the stiff plastic may damage the paint of the bicycle fork when it is snapped into place. Removal of the bicycle sound generator may cause further damage to the paint at the point of attachment.
Therefore, it can be appreciated that there is a significant need for a bicycle sound generator having a simple attachment mechanism, readily adaptable to different cross sectional shapes at the bicycle attachment location and attachment in a manner that will not damage the finish of the bicycle. The present invention provides this, and other advantages as will be apparent from the following detailed description and accompanying figures.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a perspective view of a bicycle with the sound generator of the present invention attached thereto.
FIG. 2 is a close-up of a front wheel of the bicycle of FIG. 1 showing the bicycle sound generator in its activated position.
FIG. 3 is a close-up of a front wheel of the bicycle of FIG. 1 showing the bicycle sound generator in its inactivated position.
FIG. 4 is perspective view of the bicycle sound generator prior to attachment to a bicycle.
FIG. 5 is a plan view of the bicycle sound generator of FIG. 4 .
FIG. 6 is a side view of the bicycle sound generator of FIG. 4 .
FIG. 7 is an end view of the bicycle sound generator of FIG. 4 .
FIGS. 8-12 are a series of figures showing the attachment of the bicycle sound generator of FIG. 4 at an attachment location, such as a bicycle fork.
FIGS. 13-14 are cross-sectional views of the bicycle sound generator of FIG. 4 illustrating its attachment to an attachment location, such as a bicycle fork and its displacement by spokes of the bicycle.
FIG. 15 is a plan view illustrating an alternative embodiment of the bicycle sound generator.
FIG. 16 is a plan view illustrating another alternative embodiment of the bicycle sound generator.
FIG. 17 is a side view of the bicycle sound generator of FIG. 16 .
DETAILED DESCRIPTION OF THE INVENTION
The present disclosure is directed to a sound generator 100 mounted on a bicycle 102 . The bicycle 102 includes a frame 104 , and front and rear wheels 106 - 108 . The bicycle 102 illustrated in FIG. 1 has a propulsion system 110 comprising pedals 112 and a drive mechanism 114 , which is typically a bicycle chain. The operator moves the pedals 112 to rotate the drive mechanism 114 to thereby propel the bicycle 102 . For the sake of simplicity, other mechanisms, such as gears, brakes, and the like are not shown in FIG. 1 .
The sound generator 100 may be connected to the bicycle 102 at a number of different locations, designated herein as attachment locations. One attachment location, illustrated in FIG. 1 , is a front fork 120 . As will be described in greater detail below, the bicycle sound generator 100 is positioned to make contact with spokes 122 of the front wheel 106 as the front wheel rotates.
Those skilled in the art will appreciate that the sound generator 100 can be attached to other attachment locations, such as a rear frame member 124 . In this embodiment, the sound generator 100 engages spokes 126 of the rear wheel 108 . Those skilled in the art will appreciate that other suitable attachment locations on the bicycle frame are also contemplated. For example, the bicycle may have fenders (not shown) with attachment supports. The sound generator 100 may be readily attached to a fender attachment support.
FIG. 2 illustrates a close-up of the sound generator 100 attached to the front fork 120 . As will be described in greater detail below, the sound generator 100 is snugly mounted to the front fork 120 , but is still capable of rotation thereon. FIG. 2 illustrates the sound generator 100 when rotated into an activated or engagement position where the sound generator encounters the spokes 122 of the front wheel 106 . FIG. 3 illustrates the sound generator 100 when it has been rotated to an inactive or disengagement position such that the front wheel 106 rotates freely without the sound generator 100 engaging the spokes 122 of the front wheel.
FIG. 4 is a perspective view of the sound generator 100 . In an exemplary embodiment, the sound generator 100 is manufactured from flexible plastic that freely allows the sound generator to be wrapped around the attachment location, such as the front fork 120 (see FIG. 1 ). In an exemplary embodiment, the sound generator 100 is formed from plastic having a thickness of approximately 0.015 millimeters to 1.0 millimeters. In one embodiment, a pad (not shown) such as an adhesive-backed foam pad may be added to the sound generator 100 to provide a tight fit at the selected attachment location. As illustrated in FIG. 4 , the sound generator 100 is generally elongated in shape and has a longitudinal access 130 extending from a first end 132 to a second end 134 . The sound generator 100 is generally tapered from the first end 132 to the second end 134 . In exemplary embodiment, the second end 134 is generally rounded in shape at its terminal end so is to reduce the possibility of breakage as the second end portion encounters the spokes (e.g., the spokes 122 of the front wheel 106 ). In an exemplary embodiment, the first end 132 is also generally rounded for ease of manufacturing in general aesthetic appearance. However, those skilled in the art will appreciate that the first end 132 may be manufactured in virtually any shape, such as a rectangular first end, without adversely affecting operation of the sound generator 100 .
The sound generator 100 includes two parallel slits 136 extending in a direction substantially transverse to the longitudinal access 130 . The slits 136 are spaced apart from each other to form a slot 138 through which the second end 134 will be inserted. This process will be described in greater detail below. Each of the slits 136 has a circular slit termination 140 at each end. Those skilled in the art will appreciate that the slit termination hole 140 may be used to relieve stress on the slit 136 during manufacturing, installation, and operation.
The sound generator 100 also has an aperture 144 positioned along the longitudinal access 130 . As will be described in greater detail below, the aperture 144 is positioned at a sufficient distance from the second end 134 to allow a free-end portion 146 to extend from the attachment location and engage the spokes 122 . FIG. 5 is a plan view of the sound generator 100 FIG. 4 . FIG. 6 is a side view of the sound generator 100 FIG. 4 . FIG. 7 is an end view of the sound generator 100 illustrating a convex side 148 and a concave side 150 .
As best illustrated in the end view of FIG. 7 , the sound generator 100 is formed as a cylindrical section with a cylindrical axis 152 parallel to and spaced apart from the longitudinal axis 130 (see FIG. 4 ). Although not essential for satisfactory operation of the sound generator 100 , the cylindrical section provides an anesthetically pleasing sound when it encounters spokes 122 of the front wheel 106 . Other curved shapes may also be used. The sound generator 100 is not limited by the particular curvature or lack of curvature.
FIGS. 8-12 illustrate the installation of the sound generator 100 at a location, such as the front fork 106 (see FIG. 1 ). In FIG. 8 , the concave side 150 of the sound generator 100 is pressed against the front fork 120 or other attachment location. The plastic material of the sound generator 100 is easily deformable and thus can be shaped to accommodate the particular shape of the attachment location. This is especially useful when the attachment location, such as the front fork 120 has an oval or irregular shaped cross-section.
In FIG. 9 , the sound generator 100 is wrapped around the fork 120 and, in FIG. 10 , the free-end portion 146 of the sound generator 100 is inserted in the slot 138 by passing the second end 134 through the parallel slits 136 .
In FIG. 11 , a fastener 154 is used to secure the sound generator 100 . In an exemplary embodiment, the fastener 154 is a cable tie. The advantage of using a cable tie as the fastener 154 is that the ratchet mechanism of the cable tie allows it to be tightened but it will not loosen. Thus, the cable tie 154 will securely attach the sound generator 100 and, once in place, will not loosen. Those skilled in the art will appreciate that other devices may be used as the fastener 154 . For example, string could be used instead of a cable tie. Waxed string may be particularly useful in this situation. As the waxed string is inserted into the aperture 144 and a knot formed, the wax melts slightly due to the friction of the knotting process. This causes the knot to be securely fastened and decreases the chances of the knot working itself loose. Twist ties or other devices, well known in the art, can be satisfactorily used to implement the fastener 154 . The present invention is not limited by the particular form of the fastener 154 .
In FIG. 11 , one end of the fastener 154 is inserted through the aperture 144 and wrapped around the front fork 120 . In FIG. 12 , the fastener 154 is secured which, in turn, secures the sound generator 100 on the front fork 120 . Once installation is complete, the sound generator may be rotated about the front fork 120 to move the sound generator 100 into engagement with the spokes 122 of the front wheel 106 . As previously discussed, the sound generator 100 is rotatably mounted at the attachment location. The fastener 154 securely fastens the sound generator at the attachment location. However, the plastic material used to manufacture the sound generator 100 is capable of being rotated at the attachment location. Those skilled in the art will appreciate that the use of the flexible plastic for the sound generator 100 minimizes the risk of damage to the paint on the bicycle 102 .
FIGS. 13 and 14 are cross-sectional views illustrating the operation of the sound generator 100 . In FIG. 13 , the free-end portion 146 of the sound generator 100 has been positioned so that lies in the pathway of the spokes 122 of the front wheel 106 . As the front wheel 106 rotates, the spokes 122 engage and displace the free-end portion 146 of the sound generator 100 , as illustrated in FIG. 14 . As the spoke 122 in contact with the free-end portion 146 of the sound generator 100 passes, the sound generator 100 returns to its resting position, illustrated in FIG. 13 . It is this displacement and return to the resting position that causes the characteristic sound created by the sound generator 100 .
As best illustrated in FIGS. 13 and 14 , the sound generator 100 wraps completely around the front fork 120 and readily adapts to the shape of the front fork. The fastener 154 is secured around the concave side 150 of the sound generator. Thus, the paint finish of the bicycle is protected by the sound generator 100 . The fastener 154 has no direct contact with the front fork 120 , but only wraps around the convex side 148 of the sound generator 100 .
FIG. 15 illustrates an alternative embodiment of the sound generator 100 . In this embodiment, the slits 136 are eliminated. The installation proceeds in a manner similar to that described above with respect to claims 10 - 14 . However, the sound generator 100 is wrapped around the attachment location and the second end 134 is not inserted through the slot 138 (see FIG. 10 ). Rather, the sound generator 100 is wrapped around the attachment location until the aperture 144 is positioned against the bicycle 102 at the attachment location. At that point, the fastener 154 may be inserted through the aperture and wrapped around the attachment location to secure the sound generator 100 in the manner described above.
The sound generator 100 can also be decorated in a fanciful fashion. FIG. 15 illustrates a “flame” decoration 160 mounted at the free-end portion 146 of the sound generator 100 . Those skilled in the art can appreciate that other decorations may also be used. In addition, team logos may be used in a promotional campaign. For example, a sports team may place its logo on the sound generator 100 and give the sound generator away to fans. Other campaigns such as anti-drug or anti-smoking messages may also be printed on the sound generator 100 . Thus, the sound generator may be readily used for promotional purposes. Those skilled in the art will appreciate that the decoration 160 may also be used in the embodiment illustrated in FIGS. 1-14 .
FIGS. 16 and 17 illustrate another alternative embodiment of the sound generator 100 . In this example embodiment, the first end 132 is not rounded, but is squared off. Furthermore, a crease 162 is made in the sound generator 100 proximate the first end 132 . As best illustrated in FIG. 17 , the crease 162 forms a flap 164 in the sound generator 100 . The flap 164 has a spring effect that compresses as the sound generator 100 is wrapped around the attachment location (e.g., the front fork 120 of FIG. 1 ) to provide tension to the wrap to more securely fasten the sound generator to the attachment location.
The foregoing described embodiments depict different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Furthermore, it is to be understood that the invention is solely defined by the appended claims. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations).
Accordingly, the invention is not limited except as by the appended claims. | A bicycle sound generator manufactured using a thin, deformable, plastic material. The sound generator is wrapped around an attachment location, such as a bicycle fork, and secured using a fastener. In an exemplary embodiment, the fastener is a cable tie with a one-way tightening mechanism to prevent the sound generator from coming loose once it has been attached at the attachment location. The sound generator may be rotated about the attachment location to come into an engagement position where a free-end portion of the sound generator makes contact with the spokes of a rotating wheel. When no sound is desired, the sound generator may be rotated such that the free-end portion is disengaged from the spokes and produces no sound. Graphical images, such as decorations, team logos, political messages and the like may be added to the sound generator. | 1 |
BACKGROUND OF THE INVENTION
[0001] The invention relates generally to heat sinks for electronic devices, and more specifically, to mounting and retention systems for heat sinks.
[0002] The use of heat sinks on electronic components is well known. Typically, a heat sink is arranged in close contact with a heat generating electronic component, such as a Central Processing Unit (CPU). As the power density of such components increases, heat transfer from the heat generating component to the surrounding environment becomes more and more critical to the proper operation of the component. Heat generated by the component is transferred to the heat sink and then dissipated from the heat sink to the surrounding air. One type of heat sink includes a metallic core in the form of a base plate. Heat dissipating fins extend from the base plate to increase the surface area of the heat sink. Heat transferred from the component to the base plate is spread throughout the base plate and to the fins fixed to the base plate. To further facilitate the dissipation of heat from the electronic component, a fan can be used to circulate air about outer surfaces of the fins and the base of the heat sink.
[0003] In the case of a CPU, current circuit board designs typically provide for the heat sink to be mounted directly on top of the CPU in a retention module that is in turn mounted on the circuit board. A spring clip or other fastening mechanism is used to retain the heat sink in the retention module. Thus, the installation of the heat sink is a multi-step process that involves multiple components with both assembly time and component costs adding to the cost of the product.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one embodiment of the invention, a heat sink assembly for a circuit board component is provided. The assembly includes a heat sink base, a frame coupled to the base, and a cam positionable relative to the base to lock the heat sink base to the circuit board component.
[0005] Optionally, the frame includes an actuator that has a first post and a second post. Each post has an upper end, a lower end, and a shaft portion therebetween. The lower end includes a retention lug. A cross beam interconnects the shaft portions of the posts. The frame further includes a board lock and the cam includes a lever coupled to the cam. The cam engages the actuator to move the actuator relative to the frame from a first position to a second position to lock the heat sink base to the circuit board component. The heat sink remains in the locked position when the lever is rotated from the second position to the first position.
[0006] In another embodiment, a heat sink assembly for a circuit board component is provided that includes a heat sink base, an actuator coupled to the base, and a board lock for coupling the base to the circuit board in heat transfer relationship to the circuit board component. The board lock includes a pair of retention barbs, and the actuator is configured to spread the pair of retention barbs and apply a normal force to a surface of the circuit board component when the actuator is moved from a first position to a second position.
[0007] In another embodiment, a heat sink retention assembly is provided that includes a heat sink base and a frame. The frame includes a board lock that is configured to be received in a circuit board. An actuator is received in the frame and is movable with respect to the frame from an open position to a locked position wherein the board lock is activated to retain the retention assembly on the circuit board. A cam is disposed between the frame and the actuator. The cam is rotatable from a first position to a second position to move the actuator between the open position and the locked position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of a heat sink integrated retention system in accordance with an exemplary embodiment of the present invention.
[0009] FIG. 2 is a perspective view of a frame assembly used in the system of FIG. 1 .
[0010] FIG. 3 is a perspective view of the frame member of FIG. 2 .
[0011] FIG. 4 is a perspective view of the actuator of FIG. 2 .
[0012] FIG. 5 is a perspective view of a cam lever in accordance with an exemplary embodiment of the present invention.
[0013] FIG. 6 is a partial front elevational view of the cam lever of FIG. 5 taken along sight line 6 - 6 .
[0014] FIG. 7 is a perspective view of the heat sink assembly of FIG. 1 .
[0015] FIG. 8 is a schematic view of an assembled heat sink integrated retention system in an unlocked state.
[0016] FIG. 9 is a schematic view of the heat sink integrated retention system of FIG. 8 in a locked state.
[0017] FIG. 10 is a perspective view of an alternative embodiment of a heat sink integrated retention system in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 illustrates a perspective view of an integrated retention system 10 for a heat sink assembly in accordance with an exemplary embodiment of the present invention. The integrated retention system 10 includes a heat sink assembly 20 , a fan 22 , and a housing 24 . The heat sink assembly 20 includes a heat sink base 26 with a plurality of cooling fins 28 extending upwardly from the base 26 . The heat sink base 26 and the fins 28 are typically fabricated from metal such as aluminum or copper, and further, the heat sink base 26 and the fins 28 may be fabricated from the same or different metals. For instance, in one embodiment the heat sink base 26 may be made of copper while the fins 28 may be made of aluminum.
[0019] The fan 22 is mounted above the cooling fins 28 for circulating air about the cooling fins 28 and the heat sink base 26 to facilitate the transfer of heat from a heat generating component (not shown). When in use, the heat sink base 26 is positioned in contact with the heat generating component such that heat generated by the component is transferred to the heat sink base 26 and the cooling fins 28 and then to the surrounding air.
[0020] The housing 24 holds and mounts the heat sink assembly 20 and the fan 22 to a circuit board 30 so that the heat sink base 26 is in contact with the heat generating component, and applies a compressive load to produce a normal contact force between the heat sink base 26 and the heat generating component. The housing 24 includes a pair of frame assemblies 34 and a cam lever 36 .
[0021] FIG. 2 illustrates one of the frame assemblies 34 which are identical to each other. The frame assembly 34 includes a frame member 40 and an actuator 42 . The frame member 40 includes a pair of legs 44 that each include a channel 46 that receives the actuator 42 . The actuator 42 is slidable within the channel 46 between an upper stop 48 and a lower stop 50 on each leg 44 . The frame member 40 and the actuator 42 are fabricated from a resilient material that exhibits some degree of flexibility. In one embodiment, the material is nylon 66™.
[0022] FIG. 3 illustrates the frame member 40 in detail. The frame member 40 includes upper and lower cross members 54 and 56 respectively. Cross members 54 and 56 are substantially parallel to each other and interconnect the legs 44 . Each leg 44 includes a slot 60 at an upper end 64 which extends downward to a ledge 68 . The ledges 68 at each of the four legs 44 cooperate to define a platform for the fan 22 (shown in FIG. 1 ). The upper end 64 of each leg 44 includes a pair of tabs 70 that retain the fan 22 when the integrated system 10 is assembled. The legs 44 each include a cut out 72 that defines the upper and lower actuator stops 48 and 50 respectively. Each leg 44 includes an attachment end 74 for connecting the frame member to the circuit board 30 . Each attachment end 74 includes a board lock 78 for attachment to a mounting hole (not shown) on the circuit board 30 . The board lock 78 comprises a pair of retention barbs 79 positioned one on each side of the channel 46 extending through the leg 44 such that the retention barbs 79 are separable relative to each other. The retention barbs 79 include a retaining groove 80 on an outer surface thereof and a recess 82 within the channel 46 on an inner surface 83 of the retention barbs 79 . The retaining groove 80 and the recess 82 cooperate to lock the legs 44 to the circuit board 30 as will be described below.
[0023] FIG. 4 is a perspective view illustrating the actuator 42 in detail. In one embodiment, the actuator 42 is in the shape of an H beam and includes a pair of posts 84 that are interconnected by a substantially horizontal cross beam 86 . The posts 84 are slidably received in the channels 46 (shown in FIG. 3 ) of the legs 44 . The cross beam 86 is received in the cut out 72 (shown in FIG. 2 ) in the legs 44 . The upper and lower stops 48 and 50 (shown in FIG. 3 ) in the cutout 72 interfere with the cross beam 86 to define a range of movement of the actuator 42 within the legs 44 . The posts 84 have an upper end 88 and a lower end 90 . The lower end 90 of each post 84 includes a serrated retention lug 92 that spreads the attachment ends 74 (shown in FIG. 3 ) of the legs 44 when the actuator posts 84 are drawn upward through the channel 46 . The retaining groove 80 (shown in FIG. 3 ) on the board locks 78 are sized to receive a thickness of the circuit board 30 (shown in FIG. 1 ) to lock the legs 44 onto the circuit board 30 when the board lock retention barbs 79 on the attachment ends 74 of the legs 44 are separated. The retention lugs 92 are configured to be retained in the pockets 82 in the retention barbs 79 to hold the board locks 78 in a separated position. Once the board locks 78 are in the locked position, manual thumb pressure is required to be applied to the upper ends 88 of the posts 84 to drive the retention lugs 92 from the pockets 82 to release the integrated retention system 10 from the circuit board 30 .
[0024] FIG. 5 illustrates a perspective view of the cam lever 36 . FIG. 6 illustrates a frontal view of the cam lever 36 . The cam lever 36 includes a handle 100 and a pair of lever arms 102 . A cam 104 is provided at the end of each lever arm 102 . Each cam 104 has an outer periphery 105 that includes an open flat section 106 positioned between smaller raised locking flat sections 108 . A disc 110 is also provided adjacent to cams 104 to provide a bearing surface 112 for rotating the cam lever 36 . A short pivot shaft 114 displaces the cam 104 from the disk 110 .
[0025] When installed in the integrated system 10 , the cams 104 are positioned to engage the cross beam 86 of the actuator 42 . The cam lever 36 is rotatable from a released position to a locked position. In the released position, the open flat section 106 of the cam 104 faces upward and is adjacent to cross beam 86 of the actuator 42 . In the locked position, one of the raised locking flat sections 108 engages the cross beam 86 to operate the actuator 42 . The locking flat section 108 provide a detent position so that the cam lever 36 will remain in the locked position once rotated to the locked position.
[0026] FIG. 7 is a perspective view of the heat sink assembly 20 . The heat sink assembly 20 includes cam guides 122 formed in fins 127 and 128 and channels 124 formed between fins 128 and 129 . The cam guides 122 are sized to receive the cam lever pivot shaft 114 . The channels 124 are provided to receive the cams 104 . The heat sink base also includes clearance notches 126 that receive the frame legs 44 when the integrated system 10 is assembled.
[0027] In assembling the integrated system 10 , the upper ends 88 of the actuator posts 84 (shown in FIG. 4 ) are inserted through the mounting holes 23 (see FIG. 1 ) in the fan 22 . The actuator 42 is then joined with the frame member 40 by inserting the posts 84 of the actuator 42 into the channels 46 of the legs 44 so that the cross beam 86 is positioned within the cutout 72 in the legs 44 and with the lower end 90 of the actuator posts 84 extended from the board locks 78 .
[0028] The cam lever 36 is placed over the frame assemblies 34 such that the upper cross members 54 is positioned between the lever arms 102 while the cam 104 is positioned between the lower cross members 56 . The cam lever 36 is then rotated to a position where the open flat section 106 is facing upward. Finally, the fan 22 is held in place between the ledges 68 and the tabs 70 on the legs 44 while the frame assemblies 34 are placed onto the heat sink assembly 20 with the cams 104 and the actuator cross beams 86 received in the heat sink channels 124 . The integrated system 10 can now be mounted on the circuit board 30 and locked into place by rotation of the cam lever 36 .
[0029] FIGS. 8 and 9 are schematic views of an assembled integrated retention system 10 illustrating the operation of the cam 104 and actuator 42 in mounting the integrated system 10 for cooling a heat generating component 140 . In FIG. 8 , the cam 104 is positioned in the heat sink channel 124 . The actuator cross beam 86 is engaged with the cam 104 at the open flat section 106 . The integrated system 10 is positioned on the circuit board 30 with the heat sink base 26 in contact with the heat generating component 140 . The upper ends 88 of the actuator posts 84 are depressed such that the board lock retention barbs 79 are not separated and pass unrestricted through the circuit board mounting holes 130 . In this condition, the integrated retention system 10 is not locked on the circuit board 30 . From this position, rotation of the cam lever 36 in the direction of arrow A drives the actuator 42 upward which causes the retention barbs 79 to separate to engage and retain the circuit board 30 in the retaining groove 80 (shown in FIG. 3 ) to lock the system 10 to the circuit board 30 .
[0030] In FIG. 9 , the cam lever 36 has been rotated in the direction of arrow A to lock the integrated retention system 10 to the circuit board 30 . When the cam lever 36 is rotated, the locking flat section 108 on the cam 104 engages the actuator cross beam 86 driving the actuator posts 84 upward. The upward movement of the actuator posts 84 brings the retention lugs 92 (shown in FIG. 4 ) into engagement with the attachment ends 74 , and the retention barbs 79 of board locks 78 (shown in FIG. 3 ). The retention lugs 92 separate the retention barbs 79 into the circuit board mounting holes 130 such that the retention groove 80 (shown in FIG. 3 ) retains the circuit board 30 locking the integrated system 10 to the circuit board 30 . The lugs 92 are received in the pockets 82 (shown in FIG. 3 ) of the retention barbs 79 so that the integrated system 10 remains locked onto the circuit board 30 even if the cam lever 36 is rotated in the direction of arrow B to release the actuator 42 . When it is desired to unlock the integrated system 10 , physical thumb pressure is applied to the upper ends 88 of the actuator posts 84 to drive the actuator posts 84 downward, disengaging the lugs 92 from the pockets 82 of the retention barbs 79 . The retention barbs 79 then return to their unseparated position allowing removal of the integrated system 10 from the circuit board 30 .
[0031] As shown in FIG. 9 , when the cam lever 36 is rotated in the direction of arrow A to lock the integrated system 10 to the circuit board 30 , the actuator cross beam 86 is elastically deflected in an upward direction by the cam 104 . The combined rotation of the cam lever 36 and the deflection of the cross beam 86 generate a downward compressive force resulting in a normal contact force between the heat sink base 26 and a heat generating component 140 .
[0032] FIG. 10 illustrates an integrated heat sink and retention system 150 . The integrated heat sink and retention system 150 is similar to the integrated system 10 and corresponding elements between the integrated systems 150 and 10 are given the same reference numbers in FIG. 10 . In the integrated system 150 , the heat sink base 26 is without fins. The integrated system 150 includes the heat sink base 26 , a fan 22 and a housing 24 . The system is mounted to the circuit board 30 . The cam lever 36 drives from the heat sink base 26 to rotate cams 104 . The cams 104 engage the cross beams 86 to operate the actuator 42 within the frame members 40 to lock the integrated system 150 to the circuit board 30 as previously described. The cams 104 engage the actuator cross beam 86 which elastically deforms to generate a downward compressive force from the heat sink base 26 the heat generating component (not shown in FIG. 10 ).
[0033] The embodiments thus described provide a heat sink and housing integrated into a single unit. The integrated system provides a cost effective alternative to attachment mechanisms requiring clips and other hardware. Having no hardware requirement, use of the integrated retention system also reduces product assembly time.
[0034] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | A heat sink assembly for a circuit board component is provided. that includes a heat sink base, a frame coupled to the base, and a cam positionable relative to the base to lock the heat sink base to the circuit board component. The frame includes an actuator that has a first post and a second post. Each post has an upper end, a lower end, and a shaft portion therebetween. The lower end includes a retention lug. A cross beam interconnects the shaft portions of the posts. The frame further includes a board lock and the cam includes a lever coupled to the cam. The cam engages the actuator to move the actuator relative to the frame from a first position to a second position to lock the heat sink base to the circuit board component. The heat sink remains in the locked position when the lever is rotated from the second position to the first position. | 7 |
TECHNICAL FIELD
[0001] This invention relates to friction stir welding and riveting, more particularly, to methods of joining multiple workpieces using a stir rivet to create a mechanical weld, an interweld, and a diffusion bond.
BACKGROUND OF THE INVENTION
[0002] Friction stir welding (FSW) is a method used to join metal workpieces. The method generally uses a cylindrical, shouldered tool with a profiled pin that is rotated at the joint line between two workpieces while being traversed along the joint line. The rotary motion of the tool generates frictional heat which serves to soften and plasticize the workpieces. This softened material, contributed by both workpieces, intermingles and is consolidated by the pin shoulder. As the pin moves laterally the frictional heating is reduced and the softened material hardens, creating a bond between the two workpieces. The best current understanding of the process is that no melting occurs and the weld is left in a fine-grained, hot worked condition with no entrapped oxides or gas porosity.
[0003] Stir rods used in conventional FSW are typically symmetrical cylinders having an enlarged fixed cap located on their upper side. The fixed cap used in conventional FSW does not engage a workpiece until the end of tool insertion, allowing a majority of the initially plasticized material to be expelled from the cavity before the cap creates a seal around the worksite. Current methods used in FSW do not teach or suggest methods of engaging a cap and a workpiece at the beginning of the process to retain the maximum amount of plasticized material in the weld zone.
SUMMARY OF THE INVENTION
[0004] This invention is based on a newly developed method which we call friction stir riveting. This method improves friction stir welding by using a stir rivet having a slideable cap. The stir rivet is rotated and advanced into a pair of workpieces to plasticize material around the rivet for stir welding the workpieces together. Near the beginning of the process, the slideable cap contacts the first workpiece. The contact between the cap and the first workpiece creates a partial seal, limiting the amount of plasticized material displaced out of the stir site. The rivet is then left in place to form a weld between the rivet and the solidified material.
[0005] The present invention utilizes a friction stir rivet having a body including an elongated cylindrical section and upper and lower stops at opposite ends of the cylindrical section. The cylindrical section of the body extends through a cap. A spring may extend between the cap and the upper stop, or the cap and a driving apparatus. An interlocking guide extends longitudinally along a portion of the cylindrical section. The interlocking guide on the cylindrical section may be a flat surface.
[0006] The cap has a central opening surrounding the cylindrical section. The central opening of the cap has an interlocking guide compatible with an interlocking guide of the cylindrical section, which causes the cap to rotate with the body. The interlocking guide in the central opening of the cap may be a flat surface. Alternatively, a threaded surface may be used to form a guide between the cylindrical section and the opening of the cap.
[0007] The upper stop forms the head of the rivet and provides a physical barrier, which can be used to compress the spring against the slideable cap, biasing the cap toward the lower stop. If the upper stop is not used to compress the spring, a retainer located on a rotary drive apparatus can compress the spring against the cap, biasing the cap against the lower stop. The upper stop limits upward travel of the cap.
[0008] The lower stop limits downward travel of the cap. The underside of the lower stop forms a lower end of the rivet which contacts the workpieces to be joined. The lower stop may be applied or formed after the cap is slid over the cylindrical section of the rivet. Once the cap is on the cylindrical section of the body the lower stop can be created or applied in any suitable manner, such as peening the lower end of the cylindrical section, deforming the lower end, pinning the lower end to act as the stop or to secure separate stop member, or by enlarging the lower end of the rivet with extra material.
[0009] A recessed socket is centrally located on the upper portion of the upper stop and is aligned with the rotational axis of the rivet. To rotate the rivet, a rotational rotary device is inserted into the recessed socket of the rivet.
[0010] The rivet, when rotated, locally softens and penetrates the workpieces, creating a cavity filled with plasticized material. Shortly after the lower end of the rivet penetrates the first workpiece, the slideable cap contacts the first workpiece to create a seal around the stir site, thereby limiting the amount of plasticized material displaced out of the cavity, ensuring that the plasticized material fills the cavity, and promoting intimate contact between the rivet and the plasticized material
[0011] As the rivet advances into the workpieces, the cap slides up the cylindrical section of the rivet toward the upper stop, while the bias of the spring continues to press the cap against the first workpiece.
[0012] Upon reaching a desired depth, the rotary motion is stopped and the stir site is cooled to provide an internally welded joint maintained together partially by the shape of the rivet and partially by the welding of the components together.
[0013] Preferably, the cylindrical section of the rivet body has a smaller radial thickness than the lower stop to create a re-entrant portion along the cylindrical section. Alternatively, threads on the cylindrical section may be used to create re-entrant portions along the cylindrical section of the body. The re-entrant portion allows plasticized material to fill in above the lower stop, thereby, increasing the mechanical retention of the rivet in the workpieces.
[0014] The slideable cap limits oxygen access to the rivet during the stirring process by creating a seal between the rivet and the first workpiece. The reduced oxygen supply around the rivet reduces the formation of oxides on the body of the rivet. Reducing oxidation allows a better bond to form between the rivet and the workpieces.
[0015] The rivet should be formed of a relatively high melting point metal or refractory metal so that the rivet has a higher melting point than the workpieces to be joined. Preferably, the rivet should have a melting point that is at least 100° Fahrenheit higher and more preferably at least 200° Fahrenheit higher than workpieces, such as aluminum. Further, the rivet should be formed of a metal of substantially greater hardness than the metal workpieces to be joined. Exemplary metals include high carbon steel, titanium (e.g. titanium 6-4) and the like. Preferably, the rivet should be formed of a metal that is capable of forming a diffusion bond with the metal workpieces to be joined.
[0016] A driving apparatus is used to rotate and press the rivet into the metal workpieces to be joined. The rivet penetrates best when it is rotated at speeds between 4,500 and 27,000 revolutions per minute. The amount of pressure needed to allow the rivet to penetrate the metal workpiece depends upon the speed of rotation. The rate of penetration is increased when the amount of pressure applied is increased, or when the revolutions per minute are increased. Under good conditions, a friction stir rivet can penetrate aluminum at up to 27 millimeters per minute.
[0017] The foregoing description is directed, as an example, to joining aluminum metal workpieces with a stir rivet made of metal with a higher temperature melting point. However, it should be understood that other fusible materials may be joined using the same process with a proper selection of compatible materials. Thus, other metals and thermoplastics may also be successfully joined with a stirring rivet and process within the guidelines above described.
[0018] These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the drawings:
[0020] [0020]FIG. 1 is a side view of an exemplary embodiment of a friction stir rivet according to the invention;
[0021] [0021]FIG. 2 is a cross-sectional view from the line 2 - 2 of FIG. 1;
[0022] [0022]FIG. 3 is a cross-sectional view showing the friction stir rivet of FIG. 1 at the conclusion of rotation during stir riveting of two workpieces together;
[0023] [0023]FIG. 4 is a cross-sectional view showing the combination of an alternative embodiment of friction stir rivet with associated rotary drive and biasing apparatus; and
[0024] [0024]FIG. 5 is a cross-sectional view showing the combination of FIG. 4 at the conclusion of rotation of the rivet during stir riveting of two workpieces together.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Referring first to FIGS. 1 and 2 of the drawings in detail, numeral 10 generally indicates a friction stir rivet 10 . Rivet 10 includes an elongated body 11 having a cylindrical section 12 with enlarged upper and lower stops 14 , 16 at opposite ends of the cylindrical section 12 . The cylindrical section 12 extends through a cap 18 and a spring 20 . An interlocking guide 22 extends longitudinally along the cylindrical section 12 . Preferably, the interlocking guide of cylindrical section 12 is a flat surface.
[0026] Cap 18 has a generally round central opening 24 fitted over the cylindrical section 12 . The central opening 24 of the cap 18 has an interlocking guide 26 that mates with the interlocking guide 22 of the cylindrical section 12 and causes the cap 18 to rotate with the cylindrical section 12 . Preferably, the interlocking guide 26 of the cap 18 is a flat surface.
[0027] The upper stop 14 forms the head of the rivet 10 and provides a physical barrier which compresses the spring 20 against the slideable cap 18 , biasing the cap 18 toward the lower stop 16 . A recessed socket 28 is centrally located on an upper portion 30 of the upper stop 14 and is aligned with a rotational axis 32 of the rivet 10 . To rotate the rivet 10 , a driving apparatus is inserted into the recessed socket 28 of the rivet 10 .
[0028] Referring to FIG. 3, the rivet 10 is shown in use, forming an assembly 33 by stir riveting a first workpiece 34 , such as a fusible aluminum sheet or plate, to a second workpiece 36 , such as a fusible aluminum frame or other substrate. In operation, the rivet 10 is rotated around its rotational axis 32 .
[0029] During rotation, downward force is applied to the rivet 10 causing a lower surface 38 of the lower stop 16 to frictionally contact an exposed surface 40 of the first workpiece 34 . The downward force and rotation of the rivet 10 cause a portion of the first workpiece 34 to plasticize, allowing the rivet 10 to penetrate the workpiece 34 and create a cavity 42 . As the rivet 10 is driven through an unexposed surface 44 of the first workpiece 34 , rivet 10 frictionally contacts an unexposed surface 46 of the second workpiece 36 . The downward force and rotation of rivet 10 cause a portion of the second workpiece 36 to plasticize, allowing rivet 10 to continue penetrating cavity 42 . As the rivet 10 is driven through the first workpiece 34 into the second workpiece 36 , the plasticized material 48 in cavity 42 is intermixed.
[0030] Shortly after the lower surface 38 of the rivet 10 penetrates the first workpiece 34 , the underside 50 of the slideable cap 18 contacts the first workpiece 34 to create a seal around the stir site, thereby limiting the amount of plasticized material displaced out of the cavity 42 . As the rivet 10 advances into the workpieces 34 , 36 , the cap 18 slides up the cylindrical section 12 of the rivet 10 , against the force of spring 20 which forces the cap 18 to press against the first workpiece 34 . The force of the cap 14 against the first workpiece 34 maintains the seal while the cap 18 travels up the cylindrical section 12 of the rivet 10 . The cap 18 acts as a retaining element, limiting the amount of plasticized material escaping throughout the process.
[0031] Upon reaching a desired depth, motion is stopped as shown in FIG. 3 and the stir site is cooled to harden the plasticized material and provide an internally welded joint. The resulting assembly 33 is then held together partially by the mechanical shape of the rivet 10 and partially by the welding of the workpieces 34 , 36 , together with bonding to the rivet to form the assembly 33 .
[0032] Preferably, rivet 10 is driven though the first workpiece 34 and partially into the second workpiece 36 until the cap 18 of the rivet 10 is partially recessed into the exposed surface 40 of the first workpiece 34 . Thereafter, the rotary motion of rivet 10 is stopped, allowing locally plasticized material 48 to harden and form several welds. Rivet 10 forms a mechanical bond between the first workpiece 34 and the second workpiece 36 . Plasticized material 48 preferably forms a diffusion bond between the rivet 10 and the first and the second workpieces 34 , 36 . Furthermore, the plasticized material 48 forms an interweld between the first workpiece 34 and the second workpiece 36 .
[0033] The cylindrical section 12 of the body 11 of rivet 10 has a smaller radial thickness than the lower stop 16 , to create a re-entrant section 52 along the cylindrical section 12 . When the rivet 10 is embedded into the workpieces 34 , 36 the re-entrant section 52 extends from the lower stop 16 up to the underside 50 of the cap 18 when the cap 18 is compressed against the upper stop 14 . Allowing plasticized material 48 to fill in between the underside 50 of the cap 18 and the lower stop 16 of the rivet 10 increases the strength of the mechanical retention around the cylindrical section 12 of the rivet 10 .
[0034] During the process, the slideable cap 18 restricts oxygen access to the rivet 10 by creating a seal between the rivet 10 and the first workpiece 34 . The reduced oxygen supply around the rivet 10 reduces the formation of oxides on the cylindrical section 12 of the rivet 10 , which provides a clean surface to form a bond with the plasticized material 48 . Allowing formation of an oxide layer would interfere with bonding between the cylindrical section 12 and the plasticized material 48 .
[0035] [0035]FIGS. 4 and 5 show a combination 53 of an alternative embodiment of friction stir rivet 54 with an associated rotary drive and biasing apparatus 55 . Rivet 54 includes an elongated body 56 having a cylindrical section 58 , an enlarged upper stop 60 and a lower stop 62 . The upper stop 60 has an angled side 64 . A receiver, such as a recessed socket 66 , is located on the upper stop 60 . Threads 68 , having a long lead, extend longitudinally along the cylindrical section 58 of the body 56 .
[0036] A slideable cap 70 is carried on the threaded cylindrical section 58 . Cap 70 has a central opening 72 including threads 74 engaging the threads 68 of the cylindrical section 58 . The cap 70 has an angled side 76 mateable with the angled side 64 of the upper stop 60 . During operation, the cap 70 slides up the threads 68 of the cylindrical section 58 , rotating slightly until the cap 70 engages the upper stop 60 .
[0037] To rotate the rivet 54 , a driving apparatus 55 , including a driver 80 and a biasing device 82 , engages the rivet 54 . The biasing device 82 surrounds the driver 80 and includes a telescoping retainer 84 , housing a biasing spring 86 .
[0038] In operation, the driver 80 engages the receiver 66 located on the upper stop 60 of the rivet 54 , while the biasing device 82 urges the cap 70 towards the lower stop 62 . As the rivet 54 is driven into the workpieces 88 the cap 70 rotates slightly as it slides up the threads 68 of cylindrical section 58 of the rivet 54 , which compresses the biasing device 82 against the driver 80 . The biasing spring 86 , housed inside the retainer 84 , continuously urges the cap 70 toward the lower stop 62 , causing the cap 70 to maintain contact with the exposed surface 90 of the first workpiece 92 . Upon reaching a desired depth, motion is stopped as shown in FIG. 5. Once rotational motion stops the driving apparatus 55 , the retainer 84 , and the spring 86 are disengaged from the rivet 54 , leaving the rivet 54 fixed in the joined workpieces 88 .
[0039] The threads 68 along the cylindrical section 58 of the rivet 54 , create re-entrant portions 94 along the cylindrical section 58 . When the rivet 54 is embedded in the workpieces 88 , the re-entrant portions 94 receive some of the plasticized material 96 that fills in between the underside 98 of the cap 70 and the lower stop 62 of the body 54 to increase the strength of the mechanical retention around the cylindrical section 58 of the rivet 54 .
[0040] During the process, the slideable cap 70 restricts oxygen access to the rivet 54 by creating a partial seal between the rivet and the first workpiece 92 . The reduced oxygen supply around the rivet 54 reduces the formation of oxides on the cylindrical section 58 of the rivet 54 , which provides a clean surface to form a bond with the plasticized material 96 . Allowing formation of an oxide layer would interfere with bonding between the cylindrical section 58 and the plasticized material 96 .
[0041] While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims. | A friction stir rivet is rotated and driven through a first fusible workpiece into an engaged second fusible workpiece, causing local portions of the first and second workpieces to plasticize. A slideable cap contacts the exposed surface of the first workpiece shortly after the process begins. The contact causes the cap to act as a retaining element, limiting the escape of plasticized material from stir site. Once the rivet is driven into the first and second workpieces, rotation ceases and the plasticized material hardens around the rivet. A weld is thus created, joining the workpieces and encompassing the rivet, which provides additional mechanical strength. | 8 |
BACKGROUND
[0001] A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section.
[0002] A fuel system for a gas turbine engine meters and controls fuel flow to the combustor and other portions of the gas turbine engine that utilizes fuel flow and pressure for operating actuators and other control elements. During startup and shutdown of the gas turbine engine fuel flow and pressure may be below desired levels for operation. It is desirable to prevent fuel flow to the gas turbine engine, actuators and other control elements until such time as required pressure and flow are present. It is therefore desirable to control and prevent fuel flow to the combustor and other elements of the gas turbine engine until such time as the fuel pressure and flow are within a predetermined operating range.
SUMMARY
[0003] A disclosed fuel system for a gas turbine engine includes a minimum pressure shut-off valve for closing off fuel flow to an outlet in response to fuel pressure being below a predefined pressure. The shut-off valve includes a sleeve defining a bore that extends along an axis and includes at least a first flow window and a second window. The second window includes a notch for providing a flow area based on an axial position of a spool moveable within the sleeve. The spool controls or allows fuel flow through the first and second windows when fuel pressure is above a minimum level and closes off fuel flow below the minimum value.
[0004] Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples.
[0005] These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic view of an example gas turbine engine.
[0007] FIG. 2 is a schematic view of an example fuel system for a gas turbine engine.
[0008] FIG. 3 is an exploded view of an example minimum pressure shut-off valve.
[0009] FIG. 4 is a cross-sectional view of the example shut-off valve in a closed position.
[0010] FIG. 5 is a cross-section view of the example shut-off valve in an initial starting position.
[0011] FIG. 6 is a schematic view of a window defined within a sleeve of the shut-off valve.
[0012] FIG. 7 is a schematic view of another window defined within the sleeve of the example shut-off valve.
[0013] FIG. 8 is a cross-sectional view of the example shut-off valve in an operational mode.
[0014] FIG. 9 is a schematic view of a flow window of the shut-off valve in the operational condition.
[0015] FIG. 10 is another view of another window including a notch in an example operational position.
[0016] FIG. 11 is a cross-sectional view of the example spool.
[0017] FIG. 12 is a cross-sectional view of the example spool and sleeve.
[0018] FIG. 13 is a cross-sectional view of the example sleeve.
[0019] FIG. 14 is a side view of the example sleeve.
[0020] FIG. 15 is a sectional view through windows of the example sleeve.
DETAILED DESCRIPTION
[0021] FIG. 1 schematically illustrates an example gas turbine engine 10 that includes a fan section 12 , a compressor section 14 , a combustor section 16 and a turbine section 18 . Alternative engines might include an augmenter section (not shown) among other systems or features. The fan section 12 drives air along a bypass flow path B while the compressor section 14 draws air in along a core flow path C where air is compressed and communicated to a combustor section 16 . In the combustor section 16 , air is mixed with fuel and ignited to generate a high pressure exhaust gas stream that expands through the turbine section 18 where energy is extracted and utilized to drive the fan section 12 and the compressor section 14 . In this example, the turbine section 18 drives the fan section 12 through a geared architecture 15 such that the fan section 12 may rotate at a speed different than the turbine section 18 .
[0022] Although the disclosed non-limiting embodiment depicts a turbofan gas turbine engine, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines; for example a turbine engine including a three-spool architecture in which three spools concentrically rotate about a common axis and where a low spool enables a low pressure turbine to drive a fan via a gearbox, an intermediate spool that enables an intermediate pressure turbine to drive a first compressor of the compressor section, and a high spool that enables a high pressure turbine to drive a high pressure compressor of the compressor section 14 .
[0023] The example gas turbine engine includes a fuel system 20 that supplies fuel from a fuel supply to the combustor section 16 and also to other devices within the gas turbine engine that may utilize fuel for heat exchanging or for powering actuators.
[0024] Referring to FIG. 2 , the example fuel system 20 is schematically illustrated and includes a fuel pump 24 that receives fuel from a fuel supply 22 . The fuel pump 24 includes an inlet 32 that draws fuel from the fuel supply 22 and also receives fuel that may be bypassed or drained from the fuel system 20 . The example fuel system 20 includes a minimum pressure shut-off valve 30 and also other control valves schematically illustrated at 28 . The minimum pressure shut-off valve 30 shuts off fuel flow from the fuel system 20 to the combustor section 16 or other devices within the gas turbine engine 10 when a fuel pressure and flow falls below a predetermined minimum.
[0025] Accordingly, during operation and specifically during start-up and shut-down operation, fuel flow is shut-off to the combustor section 16 until such time as pressure and flow is above the predetermined minimum. The predetermined minimum fuel pressure and flow is that level desired for combustion and operation of other features of the gas turbine engine 10 ( FIG. 1 ).
[0026] Referring to FIGS. 3 and 4 , an example shut-off valve 30 includes a main housing 34 within which is disposed a sleeve 46 and a spool 50 . The sleeve 46 is held against a forward surface 65 of the main housing 34 by a cap 38 . The example cap 38 includes threads 66 that engage complementary internal threads 64 defined within the main housing 34 . The cap 38 is threaded into the main housing 34 to hold the sleeve 46 against the forward surface 65 and a face seal 54 disposed within a chamber 56 of the main housing 34 .
[0027] The cap 38 also holds a spring 40 against the spool 50 disposed within the sleeve 46 . The spring 40 is held in place on an end opposite the spool 50 by a spring seat 42 . The example spring seat 42 is threaded into threads 68 in the cap 38 such that it can be adjusted to provide an adjustment of the biasing force provided by the spring 40 . The spring biases the spool 50 towards a closed position shown in FIG. 4 . A plug 44 is threaded into the cap 38 to seal off the opening interface through the thread 70 of the spring seat 42 is received within the cap 38 .
[0028] The spool 50 is received within a bore of the sleeve 46 and is movable responsive to pressure differences between an inlet 58 , an outlet 60 , and a control port 62 defined within the main housing 34 . The control port 62 communicates fluid pressure to a back side of the spool 50 . Fuel entering the inlet 58 will proceed through windows defined in the sleeve 46 and then through the outlet 60 . The specific axial relationship of the spool 50 relative to the sleeve 46 uncover windows 78 , 76 defined within the sleeve 46 to govern fluid flow between the inlet 58 and the outlet 60 . A spool seal 52 is disposed between the spool 50 and the sleeve 46 . A sleeve seal 48 is disposed between the sleeve 46 and the main housing 34 .
[0029] The spring 40 exerts a biasing force on the spool 50 that drives the spool 50 against the face seal 54 . The face seal 54 is disposed within a groove defined within the main housing 34 at the forward surface 65 . The sleeve 46 also engages the face seal 54 to prevent fuel flow around the sleeve 46 . Accordingly, fuel flow must flow from the inlet 58 through windows 76 , 78 defined in the sleeve 46 and out the outlet 60 . The spool 50 selectively blocks the windows 76 , 78 defined within the sleeve 46 to govern and regulate fluid flow through the outlet 60 .
[0030] The disclosed shut-off valve 30 is actuateable responsive to a pressure differential across the spool 50 in combination with the biasing force provided by the spring 40 . Pressure is communicated to through the control port 62 to a back side of the spool 50 . Fuel pressure at the inlet 58 must rise to a level above the combined forces provided by the fuel pressure and spring force on the spool 50 . The shut-off valve 30 is shown in FIG. 4 in a closed position. In the closed position, the spring force and pressure forces are at an imbalance condition that holds the spool against the face seal 54 to prevent fuel flow.
[0031] Referring to FIG. 5 , the example shut-off valve 30 is shown in an initial startup position. In the initial startup position, fuel pressure at the inlet is increased to generate an imbalance that lifts the spool 50 off the face seal 54 such that a passageway from the inlet 58 to the outlet 60 is provided.
[0032] Referring to FIGS. 6 and 7 with continued reference to FIG. 5 , the example sleeve 46 includes four windows, two without a notch indicated at 76 and two that includes a notch 84 indicated at 78 . Each of the windows 76 , 78 includes a generally oval shape. The notched window 78 includes the notch 84 that extends axially forward of the oval shaped common with windows 76 .
[0033] In an initial startup position illustrated in FIG. 5 , the spool 50 moves axially rearward off of the face seal 54 to uncover the notch portion 80 of the window 78 . Accordingly, the notch portion 80 provides the fuel flow area 84 from the inlet 58 through the outlet 60 . The remaining portions of the windows 76 , 78 are blocked as indicated at 86 . In this position, only the windows 78 that includes the notch 80 accommodates fuel flow between the inlet 58 and the outlet 60 . The other windows 76 remain blocked and do not allow fuel flow.
[0034] Referring to FIGS. 8 , 9 , and 10 , the control shut-off valve 30 is shown in a partially open position where the forces exerted on the spool valve 50 are in a balanced condition such that the spool valve 50 has opened more flow area for flow between the inlet 58 and the outlet 60 . In this example, the spool 50 is moved such that not only are the notches 80 unblocked but also a portion of the windows 76 and 78 are open to fuel flow.
[0035] The axial stroke of the spool 50 indicated at 88 corresponds to a desired flow area of the windows 76 , 78 open to fuel flow between the inlet 58 and outlet 60 . In one non-limiting dimensional embodiment, the axial stroke 88 of the spool 50 is approximately 0.040 inches (1.016 mm) The axial stroke corresponds within an opening flow area 84 between all of the windows 76 , 78 . In this example, the axial position of the spool 50 is related to the opening area 84 of the flow window 76 , 78 by a ratio between 0.000 and 1.2600. In another disclosed example embodiment an axial position of the spool is related to the opening area by a ratio between 0.000 and 1.2438.
[0036] Referring to FIGS. 11-15 , the example spool 50 and sleeve 46 are shown in cross-section. The total stroke range 82 of the spool 50 relative to the sleeve 46 provides the desired gain in fuel pressure relative to the axial position. The example sleeve 46 includes the four windows 76 , 78 , although a different number of windows could be utilized and is within the contemplation of this invention to provide the desired flow area relative to an axial position of the spool 50 .
[0037] The sleeve 46 includes a bore 75 having a diameter 72 that corresponds with an outer diameter 92 of the spool 50 to provide a clearance. The clearance between the spool 50 and the sleeve 46 prevents leakage past the spool 50 while allowing movement within the bore 75 . In one disclosed example, a ratio between the bore diameter 72 and the outer diameter 92 of the sleeve 50 is between 0.9980 and 0.9990. In another disclosed example, the ratio of the bore diameter 72 to the outer diameter 92 of the spool 50 is between about 0.9994 and 0.9996.
[0038] The clearance between the spool 50 and the bore 75 defines an annular spacing related to the outer diameter of the spool 50 . In one non-limiting dimensional embodiment, the clearance between the bore diameter 72 and outer diameter 92 of the spool 50 is between about 0.0002 and 0.0007. The clearance further defines a leakage path between the spool 50 and the bore diameter 72 . A ratio of the clearance to an outer diameter 92 of the spool is indicative of the leakage path. In one disclosed example embodiment, a ratio between the clearance 94 and the outer diameter 92 of the spool is between about 0.0009700 and 0.0009800. In another example embodiment, a ratio between the clearance 94 and the outer diameter 92 is between about 0.000976 and 0.0009798.
[0039] The example spool 50 includes a seal surface 90 engages the face seal 54 to provide an effective seal diameter 96 . The seal diameter 90 accounts for pressures and forces that provide the desired seal desired for shutting off fuel flow at a minimum pressure level. In this example, the minimum seal diameter is balanced between the surface 90 and the face seal 54 . The example seal diameter is related to the outer diameter of the spool 50 according to a ratio of the seal diameter 96 to the outer diameter 92 of the spool 50 that is between about 0.8100 and 0.8350. In another disclosed example, a ratio of the seal diameter to the outer diameter 92 is between about 0.8150 and 0.8344.
[0040] Accordingly, the example shut-off valve 30 controls fuel flow to maintain a minimum pressure desired for operation. Moreover, the example shut-off valve 30 stops fuel leakage from the system during shutdown and startup operations.
[0041] Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that this disclosure is more than just a material specification and that certain modifications would come and are contemplated within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this disclosure. | A minimum pressure shut-off valve closes off fuel flow responsive fuel pressure being below a predefined pressure. A sleeve includes at least a first flow window and a second flow window. The second window includes a notch providing a flow area based on an axial position of a spool moveable within the sleeve. | 8 |
CROSS-REFERENCE TO OTHER APPLICATION
This application claims priority from U.S. provisional application No. 60/098,466 filed Aug. 31 1998, which is hereby incorporated by reference.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to down-hole drilling, and especially to the optimization of drill bit parameters.
Background: Rotary Drilling
Oil wells and gas wells are drilled by a process of rotary drilling, using a drill rig such as is shown in FIG. 10 . In conventional vertical drilling, a drill bit 10 is mounted on the end of a drill string 12 (drill pipe plus drill collars), which may be miles long, while at the surface a rotary drive (not shown) turns the drill string, including the bit at the bottom of the hole.
Two main types of drill bits are in use, one being the roller cone bit, an example of which is seen in FIG. 11 . In this bit a set of cones 16 (two are visible) having teeth or cutting inserts 18 are arranged on rugged bearings on the arms of the bit. As the drill string is rotated, the cones will roll on the bottom of the hole, and the teeth or cutting inserts will crush the formation beneath them. (The broken fragments of rock are swept uphole by the flow of drilling fluid.) The second type of drill bit is a drag bit, having no moving parts, seen in FIG. 12 .
There are various types of roller cone bits: insert-type bits, which are normally used for drilling harder formations, will have teeth of tungsten carbide or some other hard material mounted on their cones. As the drill string rotates, and the cones roll along the bottom of the hole, the individual hard teeth will induce compressive failure in the formation. The bit's teeth must crush or cut rock, with the necessary forces supplied by the “weight on bit” (WOB) which presses the bit down into the rock, and by the torque applied at the rotary drive.
Background: Drill String Oscillation
The individual elements of a drill string appear heavy and rigid. However, in the complete drill string (which can be more than a mile long), the individual elements are quite flexible enough to allow oscillation at frequencies near the rotary speed. In fact, many different modes of oscillation are possible. (A simple demonstration of modes of oscillation can be done by twirling a piece of rope or chain: the rope can be twirled in a flat slow circle, or, at faster speeds, so that it appears to cross itself one or more times.) The drill string is actually a much more complex system than a hanging rope, and can oscillate in many different ways; see W AVE P ROPAGATION IN P ETROLEUM E NGINEERING , Wilson C. Chin, (1994).
The oscillations are damped somewhat by the drilling mud, or by friction where the drill pipe rubs against the walls, or by the energy absorbed in fracturing the formation: but often these sources of damping are not enough to prevent oscillation. Since these oscillations occur down in the wellbore, they can be hard to detect, but they are generally undesirable. Drill string oscillations change the instantaneous force on the bit, and that means that the bit will not operate as designed. For example, the bit may drill oversize, or off-center, or may wear out much sooner than expected. Oscillations are hard to predict, since different mechanical forces can combine to produce “coupled modes”; the problems of gyration and whirl are an example of this.
Background: Optimal Drilling with Various Formation Types
There are many factors that determine the drillability of a formation. These include, for example, compressive strength, hardness and/or abrasiveness, elasticity, mineral content (stickiness), permeability, porosity, fluid content and interstitial pressure, and state of underground stress.
Soft formations were originally drilled with “fish-tail” drag bits, which sheared the formation. Fish-tail bits are obsolete, but shear failure is still very useful in drilling soft formations. Roller cone bits designed for drilling soft formations are designed to maximize the gouging and scraping action, in order to exploit both shear and compressive failure. To accomplish this, cones are offset to induce the largest allowable deviation from rolling on their true centers. Journal angles are small and cone-profile angles will have relatively large variations. Teeth are long, sharp, and widely-spaced to allow for the greatest possible penetration. Drilling in soft formations is characterized by low weight and high rotary speeds.
Hard formations are drilled by applying high weights on the drill bits and crushing the formation in compressive failure. The rock will fail when the applied load exceeds the strength of the rock. Roller cone bits designed for drilling hard formations are designed to roll as close as possible to a true roll, with little gouging or scrapping action. Offset will be zero and journal angles will be higher. Teeth are short and closely spaced to prevent breakage under the high loads. Drilling in hard formations is characterized by high weight and low rotary speeds.
Medium formations are drilled by combining the features of soft and hard formation bits. The rock is failed by combining compressive forces with limited shearing and gouging action that is achieved by designing drill bits with a moderate amount of offset. Tooth length is designed for medium extensions as well. Drilling in medium formations is most often done with weights and rotary speeds between that of the hard and soft formations.
Back Round: Roller Cone Bit Design
The “cones” in a roller cone bit need not be perfectly conical (nor perfectly frustroconical), but often have a slightly swollen axial profile. Moreover, the axes of the cones do not have to intersect the centerline of the borehole. (The angular difference is referred to as the “offset” angle.) Another variable is the angle by which the centerline of the bearings intersects the horizontal plane of the bottom of the hole, and this angle is known as the journal angle. Thus as the drill bit is rotated, the cones typically do not roll true, and a certain amount of gouging and scraping takes place. The gouging and scraping action is complex in nature, and varies in magnitude and direction depending on a number of variables.
Conventional roller cone bits can be divided into two broad categories: Insert bits and steel-tooth bits. Steel tooth bits are utilized most frequently in softer formation drilling, whereas insert bits are utilized most frequently in medium and hard formation drilling.
Steel-tooth bits have steel teeth formed integral to the cone. (A hard facing is typically applied to the surface of the teeth to improve the wear resistance of the structure.) Insert bits have very hard inserts (e.g. specially selected grades of tungsten carbide) pressed into holes drilled into the cone surfaces. The inserts extend outwardly beyond the surface of the cones to form the “teeth” that comprise the cutting structures of the drill bit.
The design of the component elements in a rock bit are interrelated (together with the size limitations imposed by the overall diameter of the bit), and some of the design parameters are driven by the intended use of the product. For example, cone angle and offset can be modified to increase or decrease the amount of bottom hole scraping. Many other design parameters are limited in that an increase in one parameter may necessarily result in a decrease of another. For example, increases in tooth length may cause interference with the adjacent cones.
Background: Tooth Design
The teeth of steel tooth bits are predominantly of the inverted “V” shape. The included angle (i.e. the sharpness of the tip) and the length of the tooth will vary with the design of the bit. In bits designed for harder formations the teeth will be shorter and the included angle will be greater. Gage row teeth (i.e. the teeth in the outermost row of the cone, next to the outer diameter of the borehole) may have a “T” shaped crest for additional wear resistance.
The most common shapes of inserts are spherical, conical, and chisel. Spherical inserts have a very small protrusion and are used for drilling the hardest formations. Conical inserts have a greater protrusion and a natural resistance to breakage, and are often used for drilling medium hard formations.
Chisel shaped inserts have opposing flats and a broad elongated crest, resembling the teeth of a steel tooth bit. Chisel shaped inserts are used for drilling soft to medium formations. The elongated crest of the chisel insert is normally oriented in alignment with the axis of cone rotation. Thus, unlike spherical and conical inserts, the chisel insert may be directionally oriented about its center axis. (This is true of any tooth which is not axially symmetric.) The axial angle of orientation is measured from the plane intersecting the center of the cone and the center of the tooth.
Background: Bottom Hole Analysis
The economics of drilling a well are strongly reliant on rate of penetration. Since the design of the cutting structure of a drill bit controls the bit's ability to achieve a high rate of penetration, cutting structure design plays a significant role in the overall economics of drilling a well.
It has long been desirable to predict the development of bottom hole patterns on the basis of the controllable geometric parameters used in drill bit design, and complex mathematical models can simulate bottom hole patterns to a limited extent. To accomplish this it is necessary to understand first, the relationship between the tooth and the rock, and second, the relationship between the design of the drill bit and the movement of the tooth in relation to the rock. It is also known that these mechanisms are interdependent.
To better understand these relationships, much work has been done to determine the amount of rock removed by a single tooth of a drill bit. As can be seen by the forgoing discussion, this is a complex problem. For many years it has been known that rock failure is complex, and results from the many stresses arising from the combined movements and actions of the tooth of a rock bit. (Sikarskie, et al, P ENETRATION P ROBLEMS IN R OCK M ECHANICS , ASME Rock Mechanics Symposium, 1973). Subsequently, work was been done to develop quantitative relationships between bit design and tooth-formation interaction. This has been accomplished by calculating the vertical, radial and tangential movement of the teeth relative to the hole bottom, to accurately represent the gouging and scrapping action of the teeth on roller cone bits. (Ma, A N EW W AY TO C HARACTERIZE THE G OUGING -S CRAPPING A CTION OF R OLLER C ONE B ITS , Society of Petroleum Engineers No. 19448, 1989). More recently, computer programs have been developed which predict and simulate the bottom hole patterns developed by roller cone bits by combining the complex movement of the teeth with a model of formation failure. (Ma, T HE C OMPUTER S IMULATION OF THE I NTERACTION B ETWEEN THE R OLLER B IT AND R OCK , Society of Petroleum Engineers No. 29922, 1995). Such formation failure models include a ductile model for removing the formation occupied by the tooth during its movement across the bottom of the hole, and a fragile breakage model to represent the surrounding breakage.
Currently, roller cone bit designs remain the result of generations of modifications made to original designs. The modifications are based on years of experience in evaluating bit run records and dull bit conditions. Since drill bits are run under harsh conditions, far from view, and to destruction, it is often very difficult to determine the cause of the failure of a bit. Roller cone bits are often disassembled in manufacturers' laboratories, but most often this process is in response to a customer's complaint regarding the product, when a verification of the materials is required. Engineers will visit the lab and attempt to perform a forensic analysis of the remains of a rock bit, but with few exceptions there is generally little evidence to support their conclusions as to which component failed first and why. Since rock bits are run on different drilling rigs, in different formations, under different operating conditions, it is extremely difficult draw conclusion from the dull conditions of the bits. As a result, evaluating dull bit conditions, their cause, and determinig design solutions is a very subjective process. What is known is that when the cutting structure or bearing system of a drill bit fails prematurely, it can have a serious detrimental effect of the economics of drilling.
Though numerical methods are now available to model the bottom hole pattern produced by a roller cone bit, there is no suggestion as to how this should be used to improve the design of the bits other than to predict the presence of obvious problems such as tracking. For example, the best solution available for dealing with the problems of lateral vibration, is a recommendation that roller cone bits should be run at low to moderate rotary speeds when drilling medium to hard formations to control bit vibrations and prolong life, and to use downhole vibration sensors. (Dykstra, et al, EXPERIMENTAL EVALUATIONS OF DRILL STRING DYNAMICS, Amoco Report Number F94-P-80, 1994).
Force-Balanced Roller-Cone Bits, Systems, Drilling Methods, and Design Methods
The present application describes improved methods for designing roller cone bits, as well as improved drilling methods, and drilling systems. The present application teaches that roller cone bit designs should have equal mechanical downforce on each of the cones. This is not trivial: without special design consideration, the weight on bit will NOT automatically be equalized among the cones.
Roller-cone bits are normally NOT balanced, for several reasons:
Asymmetric cutting structures. Usually the rows on cones are intermeshed in order to cover fully the hole bottom and have a self-clearance effects. Therefore, even the cone shapes may be the same for all three cones, the teeth row distributions on cones are different from cone to cone. The number of teeth on cones are usually different. Therefore, the cone having more row and more teeth than other two cones may remove more rock and as a results, may spent more energy (Energy Imbalance). An energy imbalance usually leads to bit force imbalance.
Offset effects. Because of the offset, a scraping motion will be induced. This scraping motion is different from teeth row to teeth row and as a result, the scraping force (tangent force) acting on teeth is different from row to row. This will generate an imbalance force on bit.
Tracking effects. If at least one of the cones is in tracking, then this cone will gear with the hole bottom without penetration, the rock not removed by this cone will be partly removed by other two cones. As a result, the bit is unbalanced.
The applicant has discovered, and has experimentally verified, that equalization of downforce per cone is a very important (and greatly underestimated) factor in roller cone performance. Equalized downforce is believed to be a significant factor in reducing gyration, and has been demonstrated to provide substantial improvement in drilling efficiency. The present application describes bit design procedures which provide optimization of downforce balancing as well as other parameters.
A roller-cone bit will always be a strong source of vibration, due to the sequential impacts of the bit teeth and the inhomogeneities of the formation. However, many results of this vibration are undesirable. It is believed that the improved performance of balanced-downforce cones is partly due to reduced vibration.
Any force imbalance at the cones corresponds to a bending torque, applied to the bottom of the drill string, which rotates with the drill string. This rotating bending moment is a driving force, at the rotary frequency, which has the potential to couple to oscillations of the drill string. Moreover, this rotating bending moment may be a factor in biasing the drill string into a regime where vibration and instabilities are less heavily damped. It is believed that the improved performance of balanced-downforce cones may also be partly due to reduced oscillation of the drill string.
The disclosed innovations, in various embodiments, provide one or more of at least the following advantages:.
The roller cone bit is force balanced such that axial loading between the arms is substantially equal.
The roller cone bit is energy balanced such that each of the cutting structures drill substantially equal volumes of formation.
The drill bit has decreased axial and lateral operating vibration.
The cutting structures, bearings, and seals have increased lifetime and improved performance and durability.
Drill string life is extended.
The roller cone bit has minimized tracking of cutting structures, giving improved performance and extending cutting structure life.
The roller cone bit has an optimized number of teeth in a given formation area.
Bit performance is improved.
Off-center rotation is minimized.
The roller cone bit has optimized (minimized and equalized) uncut formation ring width.
Energy balanced roller cone bits can be further optimized by minimizing cone and bit tracking.
Energy balanced roller cone bits can be further optimized by minimizing and equalizing uncut formation rings.
Designer can evaluate the force balance and energy balance conditions of existing bit designs.
Designer can design force balanced drill bits with predictable bottom hole patterns without relying on lab tests followed by design modifications.
Designer can optimize the design of roller cone drill bits within designer-chosen constraints.
Other advantages of the various disclosed inventions will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, a sample embodiment is disclosed.
U.S. patent application Ser. No. 09/387,304, filed Aug. 31, 1999, entided “Roller-Cone Bits, Systems, Drilling Methods, and Design Methods with Optimization of Tooth Orientation” (Atty. Docket No. SC-98-26), now U.S. Pat. No. 6,095,262 and claiming priority from U.S. Provisional Application No. 60/098,442 filed Aug. 31 1998, describes roller cone drill bit design methods and optimizations which can be used separately from or in synergistic combination with the methods disclosed in the present application. That application, which has common ownership, inventorship, and effective filing date with the present application, and its provisional priority application, are both hereby incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWING
The disclosed inventions will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:
FIG. 1 shows an element and how the tooth is divided into elements for tooth force evaluation.
FIG. 2 diagrammatically shows a roller cone and the bearing forces which are measured in the current disclosure.
FIG. 3 shows the four design variables of a tooth on a cone.
FIG. 4 shows the bottom hole pattern generated by a steel tooth bit.
FIG. 5 shows the layout of row distribution in a plane showing the distance between any two tooth surfaces.
FIG. 6 shows a flowchart of the optimization procedure to design a force balanced bit.
FIGS. 7A-C compare the three cone profiles before and after optimization.
FIGS. 8A-B compare the bottom hole pattern before and after optimization.
FIGS. 9A-B compare the cone layout before and after optimization.
FIG. 10 shows an example of a drill rig which can use bits designed by the disclosed method.
FIG. 11 shows an example of a roller cone bit.
FIG. 12 shows an example of a drag bit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment (by way of example, and not of limitation).
Rock Bit Computer Model
The present invention uses a single element force-cutting relationship in order to develop the total force-cutting relationship of a cone and of an entire roller cone bit. Looking at FIG. 1, each tooth, shown on the right side, can be thought of as composed of a collection of elements, such as are shown on the left side. Each element used in the present invention has a square cross section with area S e (its cross-section on the x-y plane) and length L e (along the z axis). The force-cutting relationship for this single element may be described by:
F ze =K e *σ*S e (1)
F xe =μ x *F ze (2)
F ye =μ y *F ze (3)
where F ze is the normal force and F xe , F ye are side forces, respectively, σ is the compressive strength, S e the cutting depth and k e , μ x and μ y are coefficient associated with formation properties. These coefficients may be determined by lab test. A tooth or an insert can always be divided into several elements. Therefore, the total force on a tooth can be obtained by integrating equation (1) to (3). The single element force model used in the invention has significant advantage over the single tooth or single insert model used in most of the publications. The only way to obtain a force model is by lab test. There are many types of inserts used today for roller cone bit depending on the rock type drilled. If the single insert force model is used, a lot of tests have to be done and this is very difficult if not impossible. By using the element force model, only a few tests may be enough because any kind of insert or tooth can be always divided into elements. In other words, one element model may be applied to all kinds of inserts or teeth.
After having the single element force model, the next step is to determine the interaction between inserts and the formation drilled. This step involves the determination of the tooth kinematics (local) from the bit and cone kinematics (global) as described below.
(1) The bit kinematics is described by bit rotation speed, Ω=RPM (revolutions per minute), and the rate of penetration, ROP. Both RPM and ROP may be considered as constant or as function with time.
(2) The cone kinematics is described by cone rotational speed. Each cone may have its own speed. The initial value is calculated from the bit geometric parameters or just estimated from experiment. In the calculation the cone speed may be changed based on the torque acting on the cone.
(3) At the initial time, t0, the hole bottom is considered as a plane and is meshed into small grids. The tooth is also meshed into grids (single elements). At any time t, the position of a tooth in space is fully determined. If the tooth is in interaction with the hole bottom, the hole bottom is updated and the cutting depth for each cutting element is calculated and the forces acting on the elements are obtained.
(4) The element forces are integrated into tooth forces, the tooth forces are integrated into cone forces, the cone forces are transferred into bearing forces and the bearing forces are integrated into bit forces.
(5) After the bit is fully drilled into the rock, these forces are recorded at each time step. A period time usually at least 10 seconds is simulated. The average forces may be considered as static forces and are used for evaluation of the balance condition of the cutting structure.
Evaluation of A Force Balanced Roller Cone Bit
The applied forces to bit are the weight on bit (WOB) and torque on bit (TOB). These forces will be taken by three cones. Due to the asymmetry of bit geometry, the loads on three cones are usually not equal. In other words, one of the three cones may do much more work than other two cones. With reference to FIG. 2, the balance condition of a roller cone bit may be evaluated using the following criteria:
Max(ω1, ω2, ω3)−Min(ω1, ω2, ω3)<=ω0 (4)
Max(η1, η2, η3)−Min(η1, η2, η3)<=η0 (5)
Max(λ1, λ2, λ3)−Max(λ1, λ2, λ3)<=λ0 (6)
ξ=F r /WOB*100%<=ξ0 (7)
where ωi (i=1,2,3) is defined by ωi=WOBi/WOB*100%, WOBi is the weight on bit taken by cone i. ηi is defined by ηi=Fzi/ΣFzi*100% with Fzi being the i-th cone axial force. And λi is defined by λi=Mzi/ΣMzi*100% with Mzi being the i-th cone moment in the direction perpendicular to i-th cone axis. Finally ξ is the bit imbalance force ratio with Fr being the bit imbalance force. A bit is perfectly balanced if:
ω1=ω2 ω=ω3=33.333% or ω=0.0%
η1=η2=η3=33.333% or η0=0.0%
λ1=λ2=λ3=33.333% or λ0=0.0%
ξ=0.0%
In most cases if ω0, η0, λ0, ξ0 are controlled with some limitations, the bit is balanced. The values of ω0, η0, λ0, ξ0 depend on bit size and bit type.
There is a distinction between force balancing techniques and energy balancing. A force balanced bit uses multiple objective optimization technology, which considers weight on bit, axial force, and cone moment as separate optimization objectives. Energy balancing uses only single objective optimization, as defined in equation (11) below.
Design of A Force Balanced Roller Cone Bit
As we stated in previous sections, there are many parameters which affect bit balance conditions. Among these parameters, the teeth crest length, their positions on cones (row distribution on cone) and the number of teeth play a significant role. An increase in the size of any one parameter must of necessity result in the decrease or increase of one or more of the others. And in some cases design rules may be violated. Obviously the development of optimization procedure is absolutely necessary.
The first step in the optimization procedure is to choose the design variables. Consider a cone of a steel tooth bit as shown in FIG. 3 . The cone has three rows. For the sake of simplicity, the journal angle, the offset and the cone profile will be fixed and will not be as design variables. Therefore the only design variables for a row are the crest length, Lc, the radial position of the center of the crest length, Rc, and the tooth angles, α and δ. Therefore, the number of design variables is 4 times of the total number of rows on a bit.
The second step in the optimization procedure is to define the objectives and express mathematically the objectives as function of design variables. According to equation (1), the force acting on an element is proportional to the rock volume removed by that element. This principle also applies to any tooth. Therefore, the objective is to let each cone remove the same amount of rock in one bit revolution. This is called volume balance or energy balance. The present inventor has found that an energy balanced bit will lead to force balanced in most cases. Consider FIG. 4 which shows the patterns cut by each cone on the hole bottom. The first rows of all three cones have overlap and the inner rows remove the rock independently. Suppose the bit has a cutting depth Δ in one bit revolution. It is not difficult to calculate the volumes removed by each row and the volume matrix may have the form:
V=[V ij ], i=1,2,3; j=1,2,3,4, (8)
where i represent the cone number andj the row number. For example, V 32 is the element in the volume matrix representing the rock volume removed by the second row of the third cone. The elements V ij of this matrix are all functions of the design variables.
In reality, the removed volume by each row depends not only on the above design variables, but also on the number of teeth on that row and the tracking condition. Therefore the volume matrix calculated in a 2D manner must be scaled. The scale matrix, K v , may be obtained as follows.
K v (ij)=V 3d0 (ij)/V 2d0 (i,j) (9)
where V 3d0 is the volume matrix of the initial designed bit (before optimization). V 3d0 is obtained from the rock bit computer program by simulate the bit drilling procedure at least 10 seconds. V 2d0 is the volume matrix associated with the initial designed matrix and obtained using the 2D manner based on the bottom pattern shown in FIG. 4 . The volume matrix has the final form:
V b (i,j)=K(i,j)*V(i,j)=f v (L c , R c , α, β) (10)
Let V 1 , V 2 and V 3 be the volume removed by cone 1,2 and 3, respectively. For the energy balance, the objective function takes the following form:
Obj=(V 1 −V m ){circumflex over ( )}2+(V 2 −V m ){circumflex over ( )}2+(V 3 −V m ){circumflex over ( )}2 (11)
where V m =(V 1 +V 2 +V 3 )/3;
The third step in the optimization procedure is to defme the bounds of the design variables and the constraints. The lower and upper bounds of design variables can be determined by requirements on element strength and structural limitation. For example, the lower bound of a tooth crest length is determined by the tooth strength. The angle α and β may be limited to 0˜45 degrees. One of the most important constraints is the interference between teeth on different cones. A minimum -clearance between teeth surface must be kept. Consider FIG. 5 where cone profile is shown in a plane. A minimum clearance between tooth surfaces is required. This clearance can be expressed as a function of the design variables.
Δd=f d (L c , R c , α, β) (12)
Another constraint is the width of the uncut formation rings on bottom. The width of the uncut formation rings should be minimized or equalized in order to avoid the direct contact of cone surface to formation drilled. These constraints can be expressed as:
Δw min <=Δwi=fw i (L c , R c , α, β)<=Δw max (13)
There may be other constraints, for example, the minimum space between two neighbored rows on the same cone required by the mining process.
After having the objective function, the bounds and the constraints, the problem is simplified to a general nonlinear optimization problem with bounds and nonlinear constraints which can be solved by different methods. FIG. 6 shows the flowchart of the optimization procedure. The procedure begins by reading the bit geometry and other operational parameters. The forces on the teeth, cones, bearings, and bit are then calculated. Once the forces are known, they are compared, and if they are balanced, then the design is optimized. If the forces are not balanced, then the optimization must occur. Objectives, constraints, design variables and their bounds (maximum and minimum allowed values) are defined, and the variables are altered to conform to the new objectives. Once the new objectives are met, the new geometric parameters are used to redesign the bit, and the forces are again calculated and checked for balance. This process is repeated until the desired force balance is achieved.
As an example, FIGS. 7A-C show the row distributions on three cones of a 9″ steel tooth bit before and after optimization. FIGS. 8A and 8B compare the bottom hole patterns cut by the different cones before and after optimization. FIGS. 9A and B compare the cone layouts before and after optimization.
In the preferred embodiment of the present disclosure, a roller cone bit is provided for which the volume of formation removed by each tooth in each row, of each cutting structure (cone), is calculated. This calculation is based on input data of bit geometry, rock properties, and operational parameters. The geometric parameters of the roller cone bit are then modified such that the volume of formation removed by each cutting structure is equalized. Since the amount of formation removed by any tooth on a cutting structure is a function of the force imparted on the formation by the tooth, the volume of formation removed by a cutting structure is a direct function of the force applied to the cutting structure. By balancing the volume of formation removed by all cutting structures, force balancing is also achieved.
As another feature of the preferred embodiment, a roller cone bit is provided for which the width of the rings of formation remaining uncut is calculated, as it remains between the rows of the intermeshing teeth of the different cutting structures. The geometric parameters of the roller cone bit are then modified such that the width of the uncut area for each row is substantially minimized and equalized within selected acceptable limits. By minimizing the uncut rings on the bottom of the hole, the bit will be able to crush the uncut rings upon successive rotations due to the craters of formation removed immediately adjacent to the uncut rings. By equalizing the width of the uncut rings, the force required to crush the rings will be even from any point on the hole face, such that as cutting elements (teeth) engage the rings on successive rotations, the rings act to uniformly retain the bit drilling on-enter.
According to a disclosed class of innovative embodiments, there is provided: A roller cone drill bit comprising: a plurality of arms; rotatable cutting structures mounted on respective ones of said arms; and a plurality of teeth located on each of said cutting structures; wherein approximately the same axial force is acting on each of said cutting structure.
According to another disclosed class of innovative embodiments, there is provided: A roller cone drill bit comprising: a plurality of arms; rotatable cutting structures mounted on respective ones of said arms; and a plurality of teeth located on each of said cutting structures; wherein a substantially equal volume of formation is drilled by each said cutting structure.
According to another disclosed class of innovative embodiments, there is provided: A rotary drilling system, comprising: a drill string which is connected to conduct drilling fluid from a surface location to a rotary drill bit; a rotary drive which rotates at least part of said drill string together with said bit said rotary drill bit comprising a plurality of arms; rotatable cutting structures mounted on respective ones of said arms; and a plurality of teeth located on each of said cutting structures; wherein approximately the same axial force is acting on each said cutting structure.
According to another disclosed class of innovative embodiments, there is provided: A method of designing a roller cone drill bit, comprising the steps of: (a) calculating the volume of formation cut by each tooth on each cutting structure; (b) calculating the volume of formation cut by each cutting structure per revolution of the drill bit; (c) comparing the volume of formation cut by each of said cutting structures with the volume of formation cut by all others of said cutting structures of the bit; (d) adjusting at least one geometric parameter on the design of at least one cutting structure; and (e) repeating steps (a) through (d) until substantially the same volume of formation is cut by each of said cutting structures of said bit.
According to another disclosed class of innovative embodiments, there is provided: A method of designing a roller cone drill bit, the steps of comprising: (a) calculating the axial force acting on each tooth on each cutting structure; (b) calculating the axial force acting on each cutting structure per revolution of the drill bit; (c) comparing the axial force acting on each of said cutting structures with the axial force on the other ones of said cutting structures of the bit; (d) adjusting at least one geometric parameter on the design of at least one cutting structure; (e) repeating steps (a) through (d) until approximately the same axial force is acting on each cutting structure.
According to another disclosed class of innovative embodiments, there is provided: A method of designing a roller cone drill bit, the steps of comprising: (a) calculating the force balance conditions of a bit; (b) defining design variables; (c) determine lower and upper bounds for the design variables; (d) defining objective functions; (e) defining constraint functions; (f) performing an optimization means; and, (g) evaluating an optimized cutting structure by modeling.
According to another disclosed class of innovative embodiments, there is provided: A method of using a roller cone drill bit, comprising the step of rotating said roller cone drill bit such that substantially the same volume of formation is cut by each roller cone of said bit.
According to another disclosed class of innovative embodiments, there is provided: A method of using a roller cone drill bit, comprising the step of rotating said roller cone drill bit such that substantially the same axial force is acting on each roller cone of said bit.
Modifications and Variations
As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a tremendous range of applications, and accordingly the scope of patented subject matter is not limited by any of the specific exemplary teachings given.
Additional general background, which helps to show the knowledge of those skilled in the art regarding implementations and the predictability of variations, may be found in the following publications, all of which are hereby incorporated by reference: A PPLIED D RILLING E NGINEERING , Adam T. Bourgoyne Jr. et aL, Society of Petroleum Engineers Textbook series (1991), O IL AND G AS F IELD D EVELOPMENT T ECHNIQUES : D RILLING , J.-P. Nguyen (translation 1996, from French original 1993), M AKING H OLE (1983) and D RILLING M UD (1984), both part of the Rotary Drilling Series, edited by Charles Kirkley.
None of the description in the present application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope: THE SCOPE OF PATENTED SUBJECT MATTER IS DEFINED ONLY BY THE ALLOWED CLAIMS. Moreover, none of these claims are intended to invoke paragraph six of 35 USC section 112 unless the exact words “means for” are followed by a participle. | Roller cone drilling wherein the bit optimization process equalizes the downforce (axial force) for the cones (as nearly as possible, subject to other design constraints). Bit performance is significantly enhanced by equalizing downforce. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] Reference is made to commonly assigned, co-pending U.S. patent application Ser. No. ______ by Missell et al., filed of even date herewith (Docket 83165), entitled “Ink Jet Recording Element”.
FIELD OF THE INVENTION
[0002] This invention relates to an ink jet printing method using a porous ink jet recording element containing porous polymeric particles.
BACKGROUND OF THE INVENTION
[0003] In a typical ink jet recording or printing system, ink droplets are ejected from a nozzle at high speed towards a recording element or medium to produce an image on the medium. The ink droplets, or recording liquid, generally comprise a recording agent, such as a dye or pigment, and a large amount of solvent. The solvent, or carrier liquid, typically is made up of water, an organic material such as a monohydric alcohol, a polyhydric alcohol or mixtures thereof.
[0004] An ink jet recording element typically comprises a support having on at least one surface thereof an ink-receiving or image-forming layer, and includes those intended for reflection viewing, which have an opaque support, and those intended for viewing by transmitted light, which have a transparent support.
[0005] While a wide variety of different types of image-recording elements for use with ink jet devices have been proposed heretofore, there are many unsolved problems in the art and many deficiencies in the known products which have limited their commercial usefulness.
[0006] It is well known that in order to achieve and maintain photographic-quality images on such an image-recording element, an ink jet recording element must:
[0007] Be readily wetted so there is no puddling, i.e., coalescence of adjacent ink dots, which leads to non-uniform density
[0008] Exhibit no image bleeding
[0009] Absorb high concentrations of ink and dry quickly to avoid elements blocking together when stacked against subsequent prints or other surfaces
[0010] Exhibit no discontinuities or defects due to interactions between the support and/or layer(s), such as cracking, repellencies, comb lines and the like
[0011] Not allow unabsorbed dyes to aggregate at the free surface causing dye crystallization, which results in bloom or bronzing effects in the imaged areas
[0012] Have an optimized image fastness to avoid fade from contact with water or radiation by daylight, tungsten light, or fluorescent light
[0013] An ink jet recording element that simultaneously provides an almost instantaneous ink dry time and good image quality is desirable. However, given the wide range of ink compositions and ink volumes that a recording element needs to accommodate, these requirements of ink jet recording media are difficult to achieve simultaneously.
[0014] Inkjet recording elements are known that employ porous or non-porous single layer or multilayer coatings that act as suitable image-receiving layers on one or both sides of a porous or non-porous support. Recording elements that use non-porous coatings typically have good image quality but exhibit poor ink dry time. Recording elements that use porous coatings exhibit superior dry times, but typically have poorer image quality and are prone to cracking.
[0015] A problem with known ink jet recording elements that employ porous single layer or multilayer coatings that act as suitable image-receiving layer is dye stability during storage. In particular, dyes printed on to an inkjet receiver element tend to fade due to exposure to ozone which is present in the atmosphere.
[0016] Another problem with ink jet recording elements that employ porous single layer or multilayer coatings that act as suitable image-receiving layers is image stability under high humidity storage conditions. In particular, dyes tend to migrate through the image receiving layer during storage since the dye image receiving layer is hydrophilic and tends to absorb water from the atmosphere.
[0017] Copending U.S. patent application Ser. No. 09/608,466, filed Jun. 30, 2000, relates to an jet recording element wherein the image-receiving layer contains porous polymeric particles in a polymeric binder. However, there is a problem with this element in that during preparation of the coating solution, agglomeration of the polymeric particles occurs, which when coated, results in an element having low gloss.
[0018] JP 09207430, JP 08324101 and JP 2000/239,578 relate to porous image-receiving layers for ink jet recording elements containing inorganic particles and a poly(vinyl alcohol) having various degrees of hydrolysis. However, there is a problem with these elements in that the references do not disclose the degree of hydrolysis for the poly(vinyl alcohol) necessary to provide good gloss and low cracking.
[0019] It is an object of this invention to provide an inkjet printing method using an ink jet recording element that has a fast ink dry time. It is another object of this invention to provide an ink jet printing method using an ink jet recording element that has good stability when exposed to ozone and high humidity conditions. It is another object of the invention to provide an inkjet printing method using an ink jet recording element that has high gloss with minimal cracking.
SUMMARY OF THE INVENTION
[0020] These and other objects are achieved in accordance with the invention which comprises an ink jet printing method comprising the steps of:
[0021] A) providing an inkjet printer that is responsive to digital data signals;
[0022] B) loading the printer with an inkjet recording element comprising a support having thereon an image-receiving layer comprising porous polymeric particles in a polymeric binder, the polymeric binder comprising poly(vinyl alcohol) having a degree of hydrolysis of at least about 95% and having a number average molecular weight of at least about 45,000;
[0023] C) loading the printer with an ink jet ink composition; and
[0024] D) printing on the ink jet recording element using the ink jet ink composition in response to the digital data signals.
[0025] By use of the invention, an inkjet recording element is obtained which has a good dry time and good stability when exposed to ozone and high humidity conditions, and has high gloss with minimal cracking.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The support used in the inkjet recording element employed in the invention may be opaque, translucent, or transparent. There may be used, for example, plain papers, resin-coated papers, various plastics including a polyester resin such as poly(ethylene terephthalate), poly(ethylene naphthalate) and poly(ester diacetate), a polycarbonate resin, a fluorine resin such as poly(tetra-fluoro ethylene), metal foil, various glass materials, and the like. In a preferred embodiment, the support is paper or a voided plastic material. The thickness of the support employed in the invention can be from about 12 to about 500 μm, preferably from about 75 to about 300 μm.
[0027] The porous polymeric particles which are used in the invention are in the form of porous beads, porous irregularly shaped particles, or are aggregates of emulsion particles.
[0028] Suitable porous polymeric particles used in the invention comprise, for example, acrylic resins, styrenic resins, or cellulose derivatives, such as cellulose acetate, cellulose acetate butyrate, cellulose propionate, cellulose acetate propionate, and ethyl cellulose; polyvinyl resins such as polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate and polyvinyl butyral, polyvinyl acetal, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, and ethylene-allyl copolymers such as ethylene-allyl alcohol copolymers, ethylene-allyl acetone copolymers, ethylene-allyl benzene copolymers, ethylene-allyl ether copolymers, ethylene acrylic copolymers and polyoxy-methylene; polycondensation polymers, such as, polyesters, including polyethylene terephthalate, polybutylene terephthalate, polyurethanes and polycarbonates.
[0029] In a preferred embodiment of the invention, the porous polymeric particles are made from a styrenic or an acrylic monomer. Any suitable ethylenically unsaturated monomer or mixture of monomers may be used in making such styrenic or acrylic polymer. There may be used, for example, styrenic compounds, such as styrene, vinyl toluene, p-chlorostyrene, vinylbenzylchloride or vinyl naphthalene; or acrylic compounds, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl-α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and mixtures thereof. In another preferred embodiment, methyl methacrylate or ethylene glycol dimethacrylate is used.
[0030] In a preferred embodiment of the invention, the porous polymeric particles are crosslinked. They may have a degree of crosslinking of about 27 mole % or greater, preferably about 50 mole %, and most preferably about 100 mole %. The degree of crosslinking is determined by the mole % of multifunctional crosslinking monomer which is incorporated into the porous polymeric particles.
[0031] Typical crosslinking monomers which may be used in making the porous polymeric particles employed in the invention are aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene or derivatives thereof; diethylene carboxylate esters and amides such as ethylene glycol dimethacrylate, diethylene glycol diacrylate, and other divinyl compounds such as divinyl sulfide or divinyl sulfone compounds. Divinylbenzene and ethylene glycol dimethacrylate are especially preferred.
[0032] The porous polymeric particles used in this invention can be prepared, for example, by pulverizing and classification of porous organic compounds, by emulsion, suspension, and dispersion polymerization of organic monomers, by spray drying of a solution containing organic compounds, or by a polymer suspension technique which consists of dissolving an organic material in a water immiscible solvent, dispersing the solution as fine liquid droplets in aqueous solution, and removing the solvent by evaporation or other suitable techniques. The bulk, emulsion, dispersion, and suspension polymerization procedures are well known to those skilled in the polymer art and are taught in such textbooks as G. Odian in “Principles of Polymerization”, 2nd Ed. Wiley (1981), and W. P. Sorenson and T. W. Campbell in “Preparation Method of Polymer Chemistry”, 2nd Ed, Wiley (1968).
[0033] Techniques to synthesize porous polymer particles are taught, for example, in U.S. Pat. Nos. 5,840,293; 5,993,805; 5,403,870; and 5,599,889, and Japanese Kokai Hei 5[1993]-222108, the disclosures of which are hereby incorporated by reference. For example, an inert fluid or porogen may be mixed with the monomers used in making the porous polymer particles. After polymerization is complete, the resulting polymeric particles are, at this point, substantially porous because the polymer has formed around the porogen thereby forming the pore network. This technique is described more fully in U.S. Pat. No. 5,840,293 referred to above. Thus, the porosity of the porous polymeric particles is achieved by mixing a porogen with the monomers used to make the polymeric particles, dispersing the resultant mixture in water, and polymerizing the monomers to form the porous polymeric particles.
[0034] A preferred method of preparing the porous polymeric particles used in this invention includes forming a suspension or dispersion of ethylenically unsaturated monomer droplets containing the crosslinking monomer and a porogen in an aqueous medium, polymerizing the monomer to form solid, porous polymeric particles, and optionally removing the porogen by vacuum stripping. The particles thus prepared have a porosity as measured by a specific surface area of about 35 m 2 /g or greater, preferably 100 m 2 /g or greater. The surface area is usually measured by B.E.T. nitrogen analysis known to those skilled in the art.
[0035] The porous polymeric particles may be covered with a layer of colloidal inorganic particles as described in U.S. Pat. Nos. 5,288,598; 5,378,577; 5,563,226 and 5,750,378, the disclosures of which are incorporated herein by reference. The porous polymeric particles may also be covered with a layer of colloidal polymer latex particles as described in U.S. Pat. No. 5,279,934, the disclosure of which is incorporated herein by reference.
[0036] The porous polymeric particles used in this invention have a median diameter less than about 10 μm, preferably less than about 1 μm, and most preferably less than about 0.6 μm. Median diameter is defined as the statistical average of the measured particle size distribution on a volume basis. For further details concerning median diameter measurement, see T. Allen, “Particle Size Measurement”, 4th Ed., Chapman and Hall, (1990).
[0037] As noted above, the polymeric particles used in the invention are porous. By porous is meant particles which either have voids or are permeable to liquids. These particles can have either a smooth or a rough surface.
[0038] The image-receiving layer of the ink jet recording element employed in the invention may contain a surfactant. Suitable surfactants include anionic surfactants or cationic surfactants.
[0039] As noted above, the poly(vinyl alcohol) employed in the invention has a degree of hydrolysis of at least about 95% and has a number average molecular weight of at least about 45,000. In a preferred embodiment of the invention, the poly(vinyl alcohol) has a degree of hydrolysis of at least about 98%. In another preferred embodiment of the invention, the poly(vinyl alcohol) has a number average molecular weight of from about 70,000 to about 105,000. Commercial embodiments of such a poly(vinyl alcohol) are Gohsenol® AH-22, Gohsenol® AH-26 and Gohsenol® AH-17 from Nippon Gohsei.
[0040] The image-receiving layer may also contain additives such as pH-modifiers like nitric acid, cross-linkers, rheology modifiers, surfactants, UV-absorbers, biocides, lubricants, water-dispersible latexes, mordants, dyes, optical brighteners etc.
[0041] The image-receiving layer may be applied to one or both substrate surfaces through conventional pre-metered or post-metered coating methods such as blade, air knife, rod, roll, slot die, curtain, slide, etc. The choice of coating process would be determined from the economics of the operation and in turn, would determine the formulation specifications such as coating solids, coating viscosity, and coating speed.
[0042] The image-receiving layer thickness may range from about 5 to about 100 μm, preferably from about 10 to about 50 μm. The coating thickness required is determined through the need for the coating to act as a sump for absorption of ink solvent. The image-receiving layer employed in this invention contains from about 0.20 to about 10.0 g/m 2 of polymeric binder, preferably from about 0.40 to about 5.0 g/m 2 , and about 1.5 to about 60 g/m 2 of porous polymeric particles, preferably from about 3.0 to about 30 g/m 2 .
[0043] Inkjet inks used to image the recording elements employed in the present invention are well-known in the art. The ink compositions used in inkjet printing typically are liquid compositions comprising a solvent or carrier liquid, dyes or pigments, humectants, organic solvents, detergents, thickeners, preservatives, and the like. The solvent or carrier liquid can be solely water or can be water mixed with other water-miscible solvents such as polyhydric alcohols. Inks in which organic materials such as polyhydric alcohols are the predominant carrier or solvent liquid may also be used. Particularly useful are mixed solvents of water and polyhydric alcohols. The dyes used in such compositions are typically water-soluble direct or acid type dyes. Such liquid compositions have been described extensively in the prior art including, for example, U.S. Pat. Nos. 4,381,946; 4,239,543 and 4,781,758, the disclosures of which are hereby incorporated by reference.
[0044] The following example further illustrates the invention.
EXAMPLE
[0045] The following elements were prepared with the image-receiving layer as described:
[0046] Element 1 of the Invention
[0047] A 10% by weight solution of water, borax (sodium tetraborate decahydrate) and a sulfonated polyester dispersion AQ29® (Eastman Chemical Co.) with a coating surfactant Olin 10G®, with the borax to polyester binder ratio being 33:67, was rod coated on a corona-discharge treated resin coated paper for a total dry lay-down of 1.5 g/m 2 , giving a dry lay-down of borax of 0.5 g/m 2 and a polyester binder dry lay-down of 1.0 g/m 2 . The subbing layer coating was dried in a oven at 40° C. for 20 minutes.
[0048] A second solution at about 18% by weight comprised of porous polymeric particles, poly(ethylene glycol dimethacrylate), and a poly(vinyl alcohol) binder, AH-26 from Nippon Gohsei, where the ratio of porous polymer particles to PVA was about 80:20, was blade coated over the subbing layer to a dry lay-down of about 40 g/m 2 and dried at 40° C. for about 20 minutes to provide an image-receiving layer.
[0049] The number average molecular weight of the poly(vinyl alcohol) listed in Table 2 was estimated from the viscosity of a 4% aqueous solution according to a table provided by a commercial manufacturer of poly(vinyl alcohol). The degree of hydrolysis of the poly(vinyl alcohol) was obtained from the manufacturer.
[0050] Element 2 of the Invention
[0051] This element was prepared the same as Element 1 except that the poly(vinyl alcohol) in the image-receiving layer was AH-22 from Nippon Gohsei.
[0052] Element 3 of the Invention
[0053] This element was prepared the same as Element 1 except that the poly(vinyl alcohol) in the image-receiving layer was AH-17 from Nippon Gohsei.
[0054] Control Element C-1 (Low m.w. PVA and low degree of hydrolysis)
[0055] This element was prepared the same as Element 1 except that the poly(vinyl alcohol) in the image-receiving layer was AL-06 from Nippon Gohsei.
[0056] Control Element C-2 (Low degree of hydrolysis)
[0057] This element was prepared the same as Element 1 except that the poly(vinyl alcohol) in the image-receiving layer was GH-23 from Nippon Gohsei.
[0058] Control Element C-3 (Low degree of hydrolysis)
[0059] This element was prepared the same as Element 1 except that the poly(vinyl alcohol) in the image-receiving layer was GH-17 from Nippon Gohsei.
[0060] Control Element C-4 (Low degree of hydrolysis)
[0061] This element was prepared the same as Element 1 except that the poly(vinyl alcohol) in the image-receiving layer was KH-20 from Nippon Gohsei.
[0062] Control Element C-5 (Low degree of hydrolysis)
[0063] This element was prepared the same as Element 1 except that the poly(vinyl alcohol) in the image-receiving layer was KH-17 from Nippon Gohsei.
[0064] Testing
[0065] Each element was imaged using an Epson 870 ink jet printer and ink jet inks, Cartridge No. T007 (black) and T008 (color), and then rated for cracking to Table 1.
TABLE 1 Rating Cracking Observations 1 No visible cracks under magnification 2 Slight micro-cracks under 10X magnification 3 Very slight visible cracks under no magnification 4 Heavy cracking, some flaking 5 Heavy cracking, coating flaking off
[0066] Each element was then measured for 60 degree gloss, using a Gardner Gloss meter. The average gloss of cyan, magenta, yellow, red, blue, green, black, and D-min was recorded in Table 2. Average gloss level of greater than about 35 is acceptable.
TABLE 2 Degree of Approximate Number Cracking Element PVA Hydrolysis Average m.w. Rating Gloss 1 AH-26 98 90,000-100,000 2 45 2 AH-22 98 80,000-90,000 2 43 3 AH-17 98 60,000-65,000 4 38 C-1 AL-06 92 25,000-30,000 4 10 C-2 GH-23 88 80,000-90,000 2 10 C-3 GH-17 88 60,000-65,000 3 12 C-4 KH-20 80 70,000-80,000 3 15 C-5 KH-17 80 65,000-70,000 4 15
[0067] The above results show that the elements according to the invention having a poly(vinyl alcohol) with the degree of hydrolysis of at least about 95% and a number average molecular weight of at least about 45,000 all provide good gloss as compared to the control elements. In addition, the elements according to invention with a degree of hydrolysis of at least about 95% and an number average molecular weight of at least about 70,000 provide both in good gloss and low cracking as compared to the control elements.
[0068] This invention has been described with particular reference to preferred embodiments thereof but it will be understood that modifications can be made within the spirit and scope of the invention. | An ink jet printing method having the steps of: A) providing an ink jet printer that is responsive to digital data signals; B) loading the printer with an ink jet recording element having a support having thereon an image-receiving layer of porous polymeric particles in a polymeric binder, the polymeric binder being poly(vinyl alcohol) having a degree of hydrolysis of at least about 95% and having a number average molecular weight of at least about 45,000; C) loading the printer with an ink jet ink composition; and D) printing on the ink jet recording element using the inkjet ink composition in response to the digital data signals. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
Cross reference is made to commonly assigned co-pending patent application entitled “Solid State Light Apparatus” filed herewith, the teachings of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention is generally related to light sources, and more particularly to traffic signal lights including those incorporating both incandescent and solid state light sources.
BACKGROUND OF THE INVENTION
Traffic signal lights have been around for years and are used to efficiently control traffic through intersections. While traffic signals have been around for years, improvements continue to be made in the areas of traffic signal light control algoritluns, traffic volume detection, and emergency vehicle detection.
There continues to be a need to be able to predict when a traffic signal light source will fail. The safety issues of an unreliable traffic signal are obvious. The primary failure mechanism of an incandescent light source is an abrupt termination of the light output caused by filament breakage. The primary failure mechanism of a solid state light source is gradual decreasing of light output over time, and then ultimately, no light output.
The current state of the art for solid state light sources is as direct replacements for incandescent light sources. The life time of traditional solid state light sources is far longer than incandescent light sources, currently having a useful operational life of 10-100 times that of traditional incandescent light sources. This additional life time helps compensate for the additional cost associated with solid state light sources.
However, solid state light sources are still traditionally used in the same way as incandescent light sources, that is, continuing to operate the solid state light source until the light output is insufficient or non existent, and then replacing the light source. The light output is traditionally measured by a person with a light meter, measuring the light output from the solid state light source from a Department of Transportation (DOT) “bucket”.
Other problems with traditional traffic signal light sources is the intense heat generated by the light source. In particular, temperature greatly affects the life time of solid state light sources. If the temperature can be reduced, the operational life of the solid state light source may increase between 3 fold and 10 fold. Traditionally, solid state light sources today are designed as individual light emitting diodes (LEDs) individually mounted to a printed circuit board (PCB), and placed in a protective enclosure. This protective enclosure produces a large amount of heat and has severe heat dissipation problems, thereby reducing the life of the solid state light source dramatically.
In addition to temperature, oxidation also greatly effects the lifetime of solid state light sources. For instance, when oxygen is allowed to combine with aluminum on an aluminum gallium arsenide phosphorus (AlInGaP) LED, oxidation will occur and the light output is significantly reduced.
With specific regards to solid state light sources, typical solid state light sources comprised of LEDs are traditionally too bright early in their life, and yet not bright enough in their later stages of life. Traditional solid state light sources used in traffic control signals are traditionally over driven initially so that when the light reduces later, the light output is still at a proper level meeting DOT requirements. However, this overdrive significantly reduces the life of the LED device due to the increased, and unnecessary, drive power and associated heat of the device during the early term of use. Thus, not only is the cost for operating the signal increased, but more importantly, the overall life of the device is significantly reduced by overdriving the solid state light source during the initial term of operation.
Still another problem with traditional light sources for traffic signals is detection of the light output using the traditional hand held meter. Ambient light greatly affects the accurate detection of light output from the light source. Therefore, it has been difficult in the past to precisely set the light output to a level that meets DOT standards, but which light source is not over driven to the point of providing more light than necessary, which as previously mentioned, increases temperature and degrades the useful life of the solid state device.
Still another problem in prior art traffic signals is that signal visibility needs to be controlled so only specific lanes of traffic are able to see the traffic light. An example is when a left turn lane has a green light, and an adjacent lane is designated as a straight lane. It is necessary for traffic in the left turn lane to see the green light. The current visibility control mechanism is mechanical, typically implementing a set of baffles inserted into the light system to carefully point the light in the left lane in the correct direction. The mechanical direction system is not very controllable because it is controlled in only one dimension, typically either up or down, or, either right or left, but not both. Consequently, the light is undesirable often seen in the adjacent lane. There is arisen a need for a better method to control the visibility range of a traffic signal.
Traditionally, old technology is typically replaced with new technology by simply disposing of the old technology traffic devices. Since most cities don't have the budget to replace all traffic control devices when new ones come to market, they have traditionally taken the position of replacing only a portion of the cities devices at any given time, thereby increasing the inventory needed for the city. Larger cities end up inventorying between four and five different manufacture's traffic signals, some of which are not in production any longer. The added cost is not only for storage of inventoried items, but also the overhead of taking all different types of equipment to a repair site, or cataloging the different inventoried items at different locations.
With respect to alignment systems for traffic lights, traditionally alignment traffic control devices provide that one person points the generated light beam in the desired direction from a bucket while above the intersection, while another person stands in the traffic lanes to determine if the light is aligned properly. The person on the ground has to move over the entire field of view to check the light alignment. If the light is masked off (such as a turn arrow), there are more alignment iterations. There is desired a faster and more reliable method of aligning traffic signals.
Traffic lights also have a problem during darker conditions, i.e. at night or at dusk when the light is not well defined. This causes a problem if the light has to be masked off for any reason, whereby light may overlap to areas that should be off. This imprecise on/off boundary is called “ghosting”. There is a need to find an improved way to define the light/dark boundary of the traffic light to reduce ghosting. The ghosting is primarily caused by the angle the light hits on the “risers” on a Fresnel lens. A traffic light with a longer focal length reduces the angle, therefore decreasing the amount of ghosting. Therefore, devices with shorter focal lengths have increased ghosting. Another cause of ghosting is stray light from arrays of LED lights. Typical LED designs have a rather large intensity peek, that is, a less uniform beam of light being generated from the array.
SUMMARY OF THE INVENTION
The present invention achieves many technical advantages as an improved traffic control signal. A solid state light source has many advantageous features including the ability to predict failure of the light source, as well as an extended life time by using a heatsink to sink heat away from an LED light array, hermetically sealing the array of LEDs, and controlling the light output over time to prevent overdrive of the LED array. Other features of the present invention include providing a constant output of light from a solid state light source by providing optical feedback of light and electronic filtering to accurately detect and discern generated light from ambient light.
Other advantages of the solid state light source include an electronically steerable light beam having the ability to steer light into two dimensions, insuring only the intended lane of traffic is able to visually perceive the beam of light. In addition, the solid state light source is modularly upgradeable to allow upgrades of existing components, and the adaption of new components to keep the traffic signal state of the art. An optical sight alignment mechanism is also provided with the light source allowing a technician at the light source to determine where a beam of light generated from the light array is directed, without requiring the assistance of an on ground technician. Yet another feature of the present invention is an opto-electronic ghosting control for a light source reducing ghosting of a generated beam of light.
The solid state light of the present invention includes several new features, and several improved features, providing a state of the art solid state light source that overcomes the limitations of prior art traffic sources, including those with conventional solid state light sources.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 A and FIG. 1B is a front perspective view and rear perspective view, respectively, of a solid state light apparatus according to a first preferred embodiment of the present invention including an optical alignment eye piece;
FIG. 2 A and FIG. 2B is a front perspective view and a rear perspective view, respectively, of a second preferred embodiment having a solar louvered external air cooled heatsink;
FIG. 3 is a side sectional view of the apparatus shown in FIG. 1 illustrating the electronic and optical assembly and lens system comprising an array of LEDs directly mounted to a heatsink, directing light through a diffuser and through a Fresnel lens;
FIG. 4 is a perspective view of the electronic and optical assembly comprising the LED array, lense holder, light diffuser, power supply, main motherboard and daughterboard;
FIG. 5 is a side view of the assembly of FIG. 4 illustrating the array of LEDs being directly mounted to the heatsink, below respective lenses and disposed beneath a light diffuser, the heatsink for terminally dissipating generated heat;
FIG. 6 is a top view of the electronics assembly of FIG. 4;
FIG. 7 is a side view of the electronics assembly of FIG. 4;
FIG. 8 is a top view of the lens holder adapted to hold lenses for the array of LEDs;
FIG. 9 is a sectional view taken alone lines 9 — 9 in FIG. 8 illustrating a shoulder and side wall adapted to securely receive a respective lens for a LED mounted thereunder;
FIG. 10 is a top view of the heatsink comprised of a thermally conductive material and adapted to securingly receive each LED, the LED holder of FIG. 8, as well as the other componentry;
FIG. 11 is a side view of the light diffuser depicting its radius of curvature;
FIG. 12 is a top view of the light diffuser of FIG. 11 illustrating the mounting flanges thereof;
FIG. 13 is a top view of a Fresnel lens as shown in FIG. 3;
FIG. 14 is a perspective view of the lid of the apparatus shown in FIG. 1;
FIG. 15 is a perspective view of the optical alignment system eye piece adapted to connect to the rear of the light unit shown in FIG. 1;
FIG. 16 is a schematic diagram of the control circuitry disposed on the daughterboard and incorporating various features of the invention including control logic, as well as light detectors for sensing ambient light and reflected generated light from the light diffuser used to determine and control the light output from the solid state light;
FIG. 17 is an algorithm depicting the sensing of ambient light and backscattered light to selectably provide a constant output of light;
FIG. 18 a AND FIG. 18B are side sectional views of an alternative preferred embodiment including a heatsink with recesses, with the LED's wired in parallel and series, respectively;
FIG. 19 is an algorithm depicting generating information indicative of the light operation, function and prediction of when the said state apparatus will fail or provide output below acceptable light output;
FIGS. 20 and 21 illustrate operating characteristics of the LEDs as a function of PWM duty cycles and temperature as a function of generated output light;
FIG. 22 is a block diagram of a modular light apparatus having selectively interchangeable devices that are field replaceable;
FIG. 23 is a perspective view of a light guide having a light channel for each LED to direct the respective LED light to the diffuser;
FIG. 24 shows a top view of FIG. 23 of the light guide for use with the diffuser; and
FIG. 25 shows a side sectional view taken along line 24 — 24 in FIG. 3 illustrating a separate light guide cavity for each LED extending to the light diffuser.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1A, there is illustrated generally at 10 a front perspective view of a solid state lamp apparatus according to a first preferred embodiment of the present invention. Light apparatus 10 is seen to comprise a trapezoidal shaped housing 12 , preferably comprised of plastic formed by a plastic molding injection techniques, and having adapted to the front thereof a pivoting lid 14 . Lid 14 is seen to have a window 16 , as will be discussed shortly, permitting light generated from within housing 12 to be emitted as a light beam therethrough. Lid 14 is selectively and securable attached to housing 12 via a hinge assemble 17 and secured via latch 18 which is juxtaposed with respect to a housing latch 19 , as shown.
Referring now to FIG. 1 B and FIG. 2B, there is illustrated a second preferred embodiment of the present invention at 32 similar to apparatus 10 , whereby a housing 33 includes a solar louver 34 as shown in FIG. 2 B. The solar louver 34 is secured to housing 33 and disposed over a external heatsink 20 which shields the external heatsink 20 from solar radiation while permitting outside airflow across the heatsink 20 and under the shield 34 , thereby significantly improving cooling efficiency as will be discussed more shortly.
Referring to FIG. 2A, there is shown light apparatus 10 of FIG. 1A having a rear removable back member 20 comprised of thermally conductive material and forming a heatsink for radiating heat generated by the internal solid state light source, to be discussed shortly. Heatsink 20 is seen to have secured thereto a pair hinges 22 which are rotatably coupled to respective hinge members 23 which are securely attached and integral to the bottom of the housing 12 , as shown. Heatsink 20 is further seen to include a pair of opposing upper latches 24 selectively securable to respective opposing latches 25 forming an integral portion of and secured to housing 12 . By selectively disconnecting latches 24 from respective latches 25 , the entire rear heatsink 20 may be pivoted about members 23 to access the internal portion of housing 12 , as well as the light assembly secured to the front surface of heatsink 20 , as will be discussed shortly in regards to FIG. 3 .
Still referring to FIG. 2A, light apparatus 10 is further seen to include a rear eye piece 26 including a U-shaped bracket extending about heatsink 20 and secured to housing 12 by slidably locking into a pair of respective locking members 29 securely affixed to respective sidewalls of housing 12 . Eye piece 26 is also seen to have a cylindrical optical sight member 28 formed at a central portion of, and extending rearward from, housing 12 to permit a user to optically view through apparatus 10 via optically aligned window 16 to determine the direction a light beam, and each LED, is directed, as will be described in more detail with reference to FIG. 14 and FIG. 15 . Also shown is housing 12 having an upper opening 30 with a serrated collar centrally located within the top portion of housing 12 , and opposing opening 30 at the lower end thereof, as shown in FIG. 3 . Openings 30 facilitate securing apparatus 10 to a pair of vertical posts allowing rotation laterally thereabout.
Referring now to FIG. 3, there is shown a detailed cross sectional view taken along line 3 — 3 in FIG. 1, illustrating a solid state light assembly 40 secured to rear heatsink 20 in such an arrangement as to facilitate the transfer of heat generated by light assembly 40 to heatsink 20 for the dissipation of heat to the ambient via heatsink 20 .
Solid state light assembly 40 is seen to comprise an array of light emitting diodes (LEDs) 42 aligned in a matrix, preferably comprising an 8×8 array of LEDs each capable of generating a light output of 1-3 lumens. However, limitation to the number of LEDs or the light output of each is not to be inferred. Each LED 42 is directly bonded to heatsink 20 within a respective light reflector comprising a recess defined therein. Each LED 42 is hermetically sealed by a glass material sealingly diffused at a low temperature over the LED die 42 and the wire bond thereto, such as 8000 Angstroms of, SiO 2 or Si 3 N 4 material diffused using a semiconductor process. The technical advantages of this glass to metal hermetic seal over plastic/epoxy seals is significantly a longer LED life due to protecting the LED die from oxygen, humidity and other contaminants. If desired, for more light output, multiple LED dies 42 can be disposed in one reflector recess. Each LED 42 is directly secured to, and in thermal contact arrangement with, heatsink 20 , whereby each LED is able to thermally dissipate heat via the bottom surface of the LED. Interfaced between the planar rear surface of each LED 42 is a thin layer of heat conductive material 46 , such as a thin layer of epoxy or other suitable heat conductive material insuring that the entire rear surface of each LED 42 is in good thermal contact with rear heatsink 20 to efficiently thermally dissipate the heat generated by the LEDs. Each LED connected electrically in parallel has its cathode electrically coupled to the heatsink 20 , and its Anode coupled to drive circuitry disposed on daughterboard 60 . Alternatively, if each LED is electrically connected in series, the heatsink 20 preferably is comprised of an electrically non-conductive material such as ceramic.
Further shown in FIG. 3 is a main circuit board 48 secured to the front surface of heatsink 20 , and having a central opening for allowing LED to pass generated light therethrough. LED holder 44 mates to the main circuit board 48 above and around the LED's 42 , and supports a lens 86 above each LED. Also shown is a light diffuser 50 secured above the LEDs 42 by a plurality of standoffs 52 , and having a rear curved surface 54 spaced from and disposed above the LED solid state light source 40 , as shown. Each lens 86 (FIG. 9) is adapted to ensure each LED 42 generates light which impinges the rear surface 54 having the same surface area. Specifically, the lenses 86 at the center of the LED array have smaller radius of curvature than the lenses 86 covering the peripheral LEDs 42 . The diffusing lenses 46 ensure each LED illuminates the same surface area of light diffuser 50 , thereby providing a homogeneous (uniform) light beam of constant intensity.
A daughter circuit board 60 is secured to one end of heatsink 20 and main circuit board 48 by a plurality of standoffs 62 , as shown. At the other end thereof is a power supply 70 secured to the main circuit board 48 and adapted to provide the required drive current and drive voltage to the LEDs 42 comprising solid state light source 40 , as well as electronic circuitry disposed on daughterboard 60 , as will be discussed shortly in regards to the schematic diagram shown in FIG. 16 . Light diffuser 50 uniformly diffuses light generated from LEDs 42 of solid state light source 40 to produce a homogeneous light beam directed toward window 16 .
Window 16 is seen to comprise a lens 70 , and a Fresnel lens 72 in direct contact with lens 70 and interposed between lens 70 and the interior of housing 12 and facing light diffuser 50 and solid state light source 40 . Lid 14 is seen to have a collar defining a shoulder 76 securely engaging and holding both of the round lens 70 and 72 , as shown, and transparent sheet 73 having defined thereon grid 74 as will be discussed further shortly. One of the lenses 70 or 72 are colored to produce a desired color used to control traffic including green, yellow, red, white and orange.
It has been found that with the external heatsink being exposed to the outside air the outside heatsink 20 cools the LED die temperature up to 50° C. over a device not having a external heatsink. This is especially advantageous when the sun setting to the west late in the afternoon such as at an elevation of 10° or less, when the solar radiation directed in to the lenses and LEDs significantly increasing the operating temperature of the LED die for westerly facing signals. The external heatsink 20 prevents extreme internal operating air and die temperatures and prevents thermal runaway of the electronics therein.
Referring now to FIG. 4, there is shown the electronic and optic assembly comprising of solid state light source 40 , light diffuser 50 , main circuit board 48 , daughter board 60 , and power supply 70 . As illustrated, the electronic circuitry on daughter board 60 is elevated above the main board 48 , whereby standoffs 62 are comprised of thermally nonconductive material.
Referring to FIG. 5, there is shown a side view of the assembly of FIG. 4 illustrating the light diffuser 50 being axially centered and disposed above the solid state LED array 40 . Diffuser 50 , in combination with the varying diameter lenses 86 , facilitates light generated from the LEDs 42 to be uniformly disbursed and have uniform intensity and directed upwardly as a light beam toward the lens 70 and 72 , as shown in FIG. 3 .
Referring now to FIG. 6, there is shown a top view of the assembly shown in FIG. 4, whereby FIG. 7 illustrates a side view of the same.
Referring now to FIG. 8, there is shown a top view of the lens holder 44 comprising a plurality of openings 80 each adapted to receive one of the LED lenses 86 hermetically sealed to and bonded thereover. Advantageously, the glass to metal hermetic seal has been found in this solid state light application to provide excellent thermal conductivity and hermetic sealing characteristics. Each opening 80 is shown to be defined in a tight pack arrangement about the plurality of LEDs 42 . As previously mentioned, the lenses 86 at the center of the array, shown at 81 , have a smaller curvature diameter than the lenses 86 over the perimeter LEDs 42 to increase light dispersion and ensure uniform light intensity impinging diffuser 50 .
Referring to FIG. 9, there is shown a cross section taken alone line 9 — 9 in FIG. 8 illustrating each opening 80 having an annular shoulder 82 and a lateral sidewall 84 defined so that each cylindrical lens 86 is securely disposed within opening 80 above a respective LED 42 . Each LED 42 is preferably mounted to heatsink 20 using a thermally conductive adhesive material such as epoxy to ensure there is no air gaps between the LED 42 and the heatsink 20 . The present invention derives technical advantages by facilitating the efficient transfer of heat from LED 42 to the heatsink 20 .
Referring now to FIG. 10, there is shown a top view of the main circuit board 48 having a plurality of openings 90 facilitating the attachment of standoffs 62 securing the daughter board above an end region 92 . The power supply 48 is adapted to be secured above region 94 and secured via fasteners disposed through respective openings 96 at each comer thereof. Center region 98 is adapted to receive and have secured thereagainst in a thermal conductive relationship the LED holder 42 with the thermally conductive material 46 being disposed thereupon. The thermally conductive material preferably comprises of epoxy, having dimensions of, for instance, 0.05 inches. A large opening 99 facilitates the attachment of LED's 42 to the heatsink 20 , and such that light from the LEDs 42 is directed to the light diffuser 50 .
Referring now to FIG. 11, there is shown a side elevational view of diffuser 50 having a lower concave surface 54 , preferably having a radius A of about 2.4 inches, with the overall diameter B of the diffuser including a flange 56 being about 6 inches. The depth of the rear surface 52 is about 1.85 inches as shown as dimension C.
Referring to FIG. 12, there is shown a top view of the diffuser 50 including the flange 56 and a plurality of openings 58 in the flange 56 for facilitating the attachment of standoffs 52 to and between diffuser 50 and the heatsink 20 , shown in FIG. 4 .
Referring now to FIG. 13 there is shown the Fresnel lens 72 , preferably having a diameter D of about 12.2 inches. However, limitation to this dimension is not to be inferred, but rather, is shown for purposes of the preferred embodiment of the present invention. The Fresnel lens 72 has a predetermined thickness, preferably in the range of about {fraction (1/16)} inches. This lens is typically fabricated by being cut from a commercially available Fresnel lens.
Referring now to FIG. 14, there is illustrated the lid 14 , the hinge members 17 , and the respective latches 18 . Holder 14 is seen to further have an annular flange member 70 defining a side wall about window 16 , as shown. Further shown is transparent sheet 73 and grid 74 comprises of thin line markings defined over openings 16 defining windows 78 . The sheet can be selectively placed over window 16 for alignment, and which is removable therefrom after alignment. Each window 78 is precisionally aligned with and corresponds to one sixty four ( 64 ) LEDs 42 . Indicia 79 is provided to label the windows 78 , with the column markings preferably being alphanumeric, and the columns being numeric. The windows 78 are viable through optical sight member 28 , via an opening in heatsink 20 . The objects viewed in each window 78 are illuminated substantially by the respective LED 42 , allowing a technician to precisionally orient the apparatus 10 so that the desired LEDs 42 are oriented to direct light along a desired path and be viewed in a desired traffic lane. The sight member 28 may be provided with cross hairs to provide increased resolution in combination with the grid 74 for alignment.
Moreover, electronic circuitry 100 on daughterboard 60 can drive only selected LEDs 42 or selected 4×4 portions of array 40 , such as a total of 16 LED's 42 being driven at any one time. Since different LED's have lenses 86 with different radius of curvature different thicknesses, or even comprised of different materials, the overall light beam can be electronically steered relative to a central axis defined by window 16 .
For instance, driving the lower left 4×4 array of LEDs 42 , with the other LEDs off, in combination with the diffuser 50 and lens 70 and 72 , creates a light beam 10 degrees off a horizontal axis normal to the center of the 8×8 array of LEDs 42 , and −8 degrees off a vertical axis. Likewise, driving the upper right 4×4 array of LEDs 42 would create a light beam +10 degrees off the horizontal axis and +8 degrees to the right of a normalized vertical axis. The radius of curvature of the center lenses 86 may be, for instance, half that of the peripheral lenses 86 . A beam steerable +1−14 degrees in 2 degree increments is selectable. This feature is particularly useful when masking the opening 16 , such as to create a turn arrow. This further reduces ghosting or roll-off, which is stray light being directed in an unintended direction and viewable from an unintended traffic lane.
Referring now to FIG. 15, there is shown a perspective view of the eye piece 26 as well as the optical sight member 28 , as shown in FIG. 1 . the center axis of optical sight member 28 is oriented along the center of the 8×8 LED array.
Referring now to FIG. 16, there is shown at 100 a schematic diagram of the circuitry controlling light apparatus 10 . Circuit 10 is formed on the daughter board 60 , and is electrically connected to the LED solid state light source 40 , and selectively drives each of the individual LEDs 42 comprising the array. Depicted in FIG. 16 is a complex programmable logic device (CPLD) shown as U 1 . CPLD U 1 is preferably an off-the-shelf component such as provided by Maxim Corporation, however, limitation to this specific part is not to be inferred. For instance, discrete logic could be provided in place of CPLD U 1 to provide the functions as is described here, with it being understood that a CPLD is the preferred embodiment is of the present invention. CPLD U 1 has a plurality of interface pins, and this embodiment, shown to have a total of 144 connection pins. Each of these pin are numbered and shown to be connected to the respective circuitry as will now be described.
Shown generally at 102 is a clock circuit providing a clock signal on line 104 to pin 125 of the CPLD U 1 . Preferably, this clock signal is a square wave provided at a frequency of 32.768 KHz. Clock circuit 102 is seen to include a crystal oscillator 106 coupled to an operational amplifier U 5 and includes associated trim components including capacitors and resistors, and is seen to be connected to a first power supply having a voltage of about 3.3 volts.
Still referring to FIG. 16, there is shown at 110 a power up clear circuit comprised of an operational amplifier shown at U 6 preferably having the non-inverting output coupled to pin 127 of CPLD U 1 . The inverting input is seen to be coupled between a pair of resistors providing a voltage divide circuit, providing approximately a 2.425 volt reference signal based on a power supply of 4.85 volts being provided to the positive rail of the voltage divide network. The inverting input is preferably coupled to the 4.85 voltage reference via a current limiting resistor, as shown.
As shown at 112 , an operational amplifier U 9 is shown to have its non-inverting output connected to pin 109 of CPLD U 1 . Operational amplifier U 9 provides a power down function.
Referring now to circuit 120 , there is shown a light intensity detection circuit detecting ambient light intensity and comprising of a photodiode identified as PD 1 . An operational amplifier depicted as U 7 is seen to have its non-inverting input coupled to input pin 99 of CPLD U 1 . The non-inverting input of amplifier U 7 is connected to the anode of photodiode PD 1 , which photodiode has its cathode connected via a capacitor to the second power supply having a voltage of about 4.85 volts. The non-inverting input of amplifier U 7 is also connected via a diode Q 1 , depicted as a transistor with its emitter tied to its base and provided with a current limiting resistor. The inverting input of amplifier U 7 is connected via a resistor to input 108 of CPLD U 1 .
Shown at 122 is a similar light detection circuit detecting the intensity of backscattered light from Fresnel lens 72 as shown at 124 in FIG. 3, and based around a second photodiode PD 2 , including an amplifier U 10 and a diode Q 2 . The non-inverting output of amplifier U 10 , forming a buffer, is connected to pin 82 of CPLD U 1 .
An LED drive connector is shown at 130 serially interfaces LED drive signal data to drive circuitry of the LEDs 42 . (Inventors please describe the additional drive circuit schematic).
Shown at 140 is another connector adapted to interface control signals from CPLD U 1 to an initiation control circuit for the LED's.
Each of the LEDs 42 is individually controlled by CPLD U 1 whereby the intensity of each LED 42 is controlled by the CPLD U 1 selectively controlling a drive current thereto, a drive voltage, or adjusting a duty cycle of a pulse width modulation (PWM) drive signal, and as a function of sensed optical feedback signals derived from the photodiodes as will be described shortly here, in reference to FIG. 17 .
Referring to FIG. 17 in view of FIG. 3, there is illustrated how light generated by solid state LED array 40 is diffused by diffuser 50 , and a small portion 124 of which is back-scattered by the inner surface of Fresnel lens 72 back toward the surface of daughter board 60 . The back-scattered diffused light 124 is sensed by photodiodes PD 2 , shown in FIG. 16 . The intensity of this back-scattered light 124 is measured by circuit 122 and provided to CPLD U 1 . CPLD U 1 measures the intensity of the ambient light via circuit 120 using photodiode PD 1 . The light generated by LED's 42 is preferably distinguished by CPLD U 1 by strobing the LEDs 42 using pulse width modulation (PWM) to discern ambient light (not pulsed) from the light generated by LEDs 42 .
CPLD U 1 individually controls the drive current, drive voltage, or PWM duty cycle to each of the respective LEDs 42 as a function of the light detected by circuits 120 and 122 . For instance, it is expected that between 3 and 4% of the light generated by LED array 40 will back-scatter back from the fresnel lens 72 toward to the circuitry 100 disposed on daughter board 60 for detection. By normalizing the expected reflected light to be detected by photodiodes PD 2 in circuit 122 , for a given intensity of light to be emitted by LED array 40 through window 16 of lid 14 , optical feedback is used to ensure an appropriate light output, and a constant light output from apparatus 10 .
For instance, if the sensed back-scattered light, depicted as rays 124 in FIG. 3, is detected by photodiodes PD 2 to fall about 2.5% from the normalized expected light to be sensed by photodiodes PD 2 , such as due to age of the LEDs 42 , CPLD U 1 responsively increases the drive current to the LEDs a predicted percentage, until the back-scattered light as detected by photodiodes PD 2 is detected to be the normalized sensed light intensity. Thus, as the light output of LEDs 42 degrade over time, which is typical with LEDs, circuit 100 compensates for such degradation of light output, as well as for the failure of any individual LED to ensure that light generated by array 40 and transmitted through window 16 meets Department of Transportation (DOT) standards, such as a 44 point test. This optical feedback compensation technique is also advantageous to compensate for the temporary light output reduction when LEDs become heated, such as during day operation, known as the recoverable light, which recoverable light alos varies over temperatures as well. Permanent light loss is over time of operation due to degradation of the chemical composition of the LED semiconductor material.
Preferably, each of the LEDs is driven by a pulse width modulated (PWM) drive signal, providing current during a predetermined portion of the duty cycle, such as for instance, 50%. As the LEDs age and decrease in light output intensity, and also during a day due to daily temperature variations, the duty cycle may be responsively, slowly and continuously increased or adjusted such that the duty cycle is appropriate until the intensity of detected light by photodiodes PD 2 is detected to be the normalized detected light. When the light sensed by photodides PD 2 are determined by controller 60 to fall below a predetermined threshold indicative of the overall light output being below DOT standards, a notification signal is generated by the CPLD U 1 which may be electronically generated and transmitted by an RF modem, for instance, to a remote operator allowing the dispatch of service personnel to service the light. Alternatively, the apparatus 10 can responsively be shut down entirely.
Referring now to FIG. 18 A and FIG. 18B, there is shown an alternative preferred embodiment of the present invention including a heatsink 200 machined or stamped to have an array of reflectors 202 . Each recess 202 is defined by outwardly tapered sidewalls 204 and a base surface 208 , each recess 202 having mounted thereon a respective LED 42 . A lens array having a separate lens 210 for each LED 42 is secured to the heatsink 200 over each recess 202 , eliminating the need for a lens holder. The tapered sidewalls 206 serve as light reflectors to direct generated light through the respective lens 210 at an appropriate angle to direct the associated light to the diffuser 50 having the same surface area of illumination for each LED 42 . In one embodiment, as shown in FIG. 18A, LEDs 42 are electrically connected in parallel. The cathode of each LED 42 is electrically coupled to the electrically conductive heatsink 200 , with a respective lead 212 from the anode being coupled to drive circuitry 216 disposed as a thin film PCB 45 adhered to the surface of the heatsink 200 , or defined on the daughterboard 60 as desired. Alternatively, as shown in FIG. 18B, each of the LED's may be electrically connected in series, such as in groups of three, and disposed on an electrically non-conductive thermally conductive material 43 such as ceramic, diamond, SiN or other suitable materials. In a further embodiment, the electrically non-conductive thermally conductive material may be formed in a single process by using a semiconductor process, such as diffusing a thin layer of material in a vacuum chamber, such as 8000 Angstroms of SiN, which a further step of defining electrically conductive circuit traces 45 on this thin layer.
FIG. 19 shows an algorithm controller 60 applies for predicting when the solid state light apparatus will fail, and when the solid state light apparatus will produce a beam of light having an intensity below a predetermined minimum intensity such as that established by the DOT. Referring to the graphs in FIGS. 20 and 21, the known operating characteristics of the particular LEDs produced by the LED manufacture are illustrated and stored in memory, allowing the controller 60 to predict when the LED is about the fail. Knowing the LED drive current operating temperature, and total time the LED as been on, the controller 60 determines which operating curve in FIG. 20 and FIG. 21 applies to the current operating conditions, and determines the time until the LED will degrade to a performance level below spec, i.e. below DOT minimum intensity requirements.
FIG. 22 depicts a block diagram of the modular solid state traffic light device. The modular field-replaceable devices are each adapted to selectively interface with the control logic daughterboard 60 via a suitable mating connector set. Each of these modular field replacable devices 216 are preferably embodied as a separate card, with possibly one or more feature on a single field replacable card, adapted to attach to daughterboard 60 by sliding into or bolting to the daughterboard 60 . The devices can be selected from, alone or in combination with, a pre-emption device, a chemical sniffer, a video loop detector, an adaptive control device, a red light running (RLR) device, and an in-car telematic device, infrared sensors to sense people and vehicles under fog, rain, smode and other adverse visual conditions, automobile emission monitoring, various communication links, electronically steerable beam, exhaust emission violations detection, power supply predictive failure analysis, or other suitable traffic devices.
The solid state light apparatus 10 of the present invention has numerous technical advantages, including the ability to sink heat generated from the LED array to thereby reduce the operating temperature of the LEDs and increase the useful life thereof. Moreover, the control circuitry driving the LEDs includes optical feedback for detecting a portion of the back-scattered light from the LED array, as well as the intensity of the ambient light, facilitating controlling the individual drive currents, drive voltages, or increasing the duty cycles of the drive voltage, such that the overall light intensity emitted by the LED array 40 is constant, and meets DOT requirements. The apparatus is modular in that individual sections can be replaced at a modular level as upgrades become available, and to facilitate easy repair. With regards to circuitry 100 , CPLD U 1 is securable within a respective socket, and can be replaced or reprogrammed as improvements to the logic become available. Other advantages include programming CPLD U 1 such that each of the LEDs 42 comprising array 40 can have different drive currents or drive voltages to provide an overall beam of light having beam characteristics with predetermined and preferably parameters. For instance, the beam can be selectively directed into two directions by driving only portions of the LED array in combination with lens 70 and 72 . One portion of the beam may be selected to be more intense than other portions of the beam, and selectively directed off axis from a central axis of the LED array 40 using the optics and the electronic beam steering driving arrangement.
Referring now to FIG. 23, there is shown at 220 a light guide device having a concave upper surface and a plurality of vertical light guides shown at 222 . One light guide 222 is provided for and positioned over each LED 42 , which light guide 222 upwardly directs the light generated by the respective LED 42 to impinge the outer surface of the diffuser 54 . The guides 222 taper outwardly at a top end thereof, as shown in FIG. 24 and FIG. 25, such that the area at the top of each light guide 222 is identical. Thus each LED 42 illuminates an equal surface area of the light diffuser 54 , thereby providing a uniform intensity light beam from light diffuser 54 . A thin membrane 224 defines the light guide, like a honeycomb, and tapers outwardly to a point edge at the top of the device 220 . These point edges are separated by a small vertical distance D shown in FIG. 25, such as 1 mm, from the above diffuser 54 to ensure uniform lighting at the transition edges of the light guides 222 while preventing bleeding of light laterally between guides, and to prevent light roll-off by generating a homogeneous beam of light. Vertical recesses 226 permit standoffs 52 extending along the sides of device 220 (see FIG. 3) to support the peripheral edge of the diffuser 54 .
While the invention has been described in conjunction with preferred embodiments, it should be understood that modifications will become apparent to those of ordinary skill in the art and that such modifications are therein to be included within the scope of the invention and the following claims. | A modular solid state light apparatus ideally suited for use in traffic control signals. Current state of the art solid state signals are sealed units which fit into existing signal cases once the primary lens and incandescent bulb, and sometimes even the incandescent reflector, are removed. The modular system replaces the entire case with a custom case designed to accommodate current and future features at approximately {fraction (1/10)} the present cost of a stand alone system. These upgrade features include but are not limited to vehicle preemption, electronically steerable beam, predictive failure analysis, various power supplies, LED arrays in various colors, optical alignment tools used for installation, video camera, in car Telematics, video loop detection, red light running, various communications links, infrared sensors to sense people and vehicles under fog, rain smoke, and other adverse visual conditions, chemical ‘sniffers’, automobile emission monitoring, and adaptive control. The modular traffic functions are adapted to be selectively added and upgraded over the life of the signal, and permitting easy service thereof. | 5 |
FIELD OF THE INVENTION
This invention relates to washing cycles and more particularly though not solely to washing and/or rinsing cycles in automatic laundry washing machines.
DESCRIPTION OF THE PRIOR ART
During the washing cycle of many existing top loading laundry washing machines a number of common steps are carried out. Once the laundry load to be washed is deposited in the washing machine's spin tub (within a stationary water container), the basic steps in the washing process often include an initial wash phase where the laundry load is substantially submerged in a water/detergent mixture and the submerged wash load is washed by the action of an agitator or pulsator within the spin tub. The washing liquid is then drained and the laundry load spun at high speed in order to further centrifugally extract washing liquid from the load. This wash/drain phase is usually followed by one or more rinsing phases to further extract remaining detergent from the laundry load.
The previously mentioned rinsing phases have customarily included "deep rinse" and/or "spray rinse" phases. During a "deep rinse" phase water is admitted to the spin tub (during which time the spin tub may be slowly rotated) to the same level used in the previously described wash phase and the laundry load is agitated in the fresh water before the water is drained and a further spin phase is carried out. In comparison, during a "spray rinse" phase the spin tub is rotated at a relatively high speed while water is sprayed onto the laundry load which is held against the base and walls of the spin tub by the rotation of the spin tub. The water is continuously drained so that the incoming water passes through the laundry load and out the drain, taking with it some of the detergent remaining in the laundry load.
The washing cycle is usually completed by a high speed spin in which a large proportion of the remaining water in the laundry load is centrifugally extracted.
Washing cycles including the combination of the previously described "deep rinse" and "spray rinse" phases have the disadvantage that they require large quantities of water, subsequently reducing the water efficiency of the laundry washing machine. Accordingly, front loading (or horizontal axis) washing machines, which do not require that the laundry load be substantially submerged but rather continuously pass the tumbling load through a bath of water, have historically obtained much better water efficiency statistics than their top loading counterparts.
Attempts have been made to improve the water efficiency of top loading washing machines by, for example, recirculating the wash water for later use during the rinsing phases. Water recirculation has the disadvantage that the amount of detergent, lint and soil subsequently removed from the laundry load is reduced. An example of a top loading laundry washing machine which employs both the aforementioned "spray rinse", "deep rinse" as well as water recirculation techniques to improve the water efficiency of the machine is disclosed in New Zealand Patent No. 236665 published on 26 May 1993 (equivalent to U.S. Pat. No. 5,167,722 issued on 1 Dec. 1992) to Whirlpool Corporation. European Patent Specification No. 394657 to Bosch Siemens Hausgerate published on 31 Oct. 1990 discloses a multiple rinse laundry washing machine in which the duration of each rinse cycle and the water level during each rinse cycle is determined from the immediately preceding rinse cycle in order to decrease the overall duration of the washing cycle. The object of the invention disclosed is therefore to reduce the time rather than the amount of water used during the washing cycle and accordingly the water efficiency of such a machine will not be improved.
BRIEF SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a method of washing a load in a washing machine which goes at least some way towards overcoming the above disadvantages or which will at least provide the public with a useful choice.
Accordingly, in one aspect, the invention consists in a method of washing and rinsing a load in a washing liquid and detergent solution during a washing cycle of a laundry washing machine having a rotatable spin tub within a stationary water container, the walls of said spin tub having a number of holes therein to allow liquid flow between said spin tub and said water container, a valve means to control admission of washing liquid to said spin tub, draining means to control the removal of said washing liquid from said water container, control means including timing means to determine the duration of selected functions of said washing machine and washing liquid level determining means, said method comprising the steps of:
i) commencing a washing phase of said washing cycle in which said valve means admits washing liquid to said spin tub and said load is washed in said liquid and detergent solution,
ii) operating said draining means to drain a substantial amount of said washing liquid and detergent from said water container,
iii) commencing a washing liquid and detergent extraction phase of said washing cycle to centrifugally extract washing liquid and detergent from said load by rotating said spin tub at a first speed for a predetermined length of time to cause said washing liquid and detergent to pass from said load, through said holes in said spin tub walls and into said water container while said draining means is operated to remove said washing liquid and said detergent from said water container,
iv) commencing a sensing rinse phase of Said washing cycle by initiating admission of washing liquid into said spin tub while starting said timing means and causing said draining means to prevent said washing liquid from being removed from said water container,
v) completing said sensing rinse by ending said admission of washing liquid to said spin tub when said washing liquid level indicating means indicates that the level of washing liquid in said water container has reached a predetermined level and stopping said timing means, said timing means indicating a sensed time representative of a sensed volume of washing liquid admitted to said spin tub during said sensing rinse phase,
vi) operating said draining means to cause extraction of washing liquid and detergent from said water container and commencing a further washing liquid and detergent extraction phase of said washing cycle by rotating said spin tub at a second speed to centrifugally extract washing liquid and detergent from said load,
vii) commencing a further rinse phase by operating said washing liquid admission means to cause a predetermined fraction of said sensed volume of said washing liquid to be admitted to said spin tub,
viii) rotating said spin tub at a third spin speed to centrifugally extract washing liquid and detergent from said load, and
ix) repeating steps (vii) and (viii) a number of times until the end of said washing cycle is reached.
In a second aspect, the invention consists in a laundry washing machine having a rotatable spin tub within a stationary water container, the walls of said spin tub having a number of holes therein to allow liquid flow between said spin tub and said water container, a valve means to control admission of washing liquid to said spin tub, draining means to control the removal of said washing liquid from said water container, control means which control the operation of said machine which includes timing means to determine the duration of selected functions of said washing machine and washing liquid level determining means, said control means storing a program which causes the control means to:
i) commence a washing phase of said washing cycle in which said valve means admits washing liquid to said spin tub and said load is washed in said liquid and detergent solution,
ii) operate said draining means to drain a substantial mount of said washing liquid and detergent from said water container,
iii) commence a washing liquid and detergent extraction phase of said washing cycle to centrifugally extract washing liquid and detergent from said load by rotating said spin tub at a first speed for a predetermined length of time to cause said washing liquid and detergent to pass from said load, through said holes in said spin tub walls and into said water container while said draining means is operated to remove said washing liquid and said detergent from said water container,
iv) commence a sensing rinse phase of said washing cycle by initiating admission of washing liquid into said spin tub while starting said timing means and causing said draining means to prevent said washing liquid from being removed from said water container,
v) complete said sensing rinse by ending said admission of washing liquid to said spin tub when said washing liquid level indicating means indicates that the level of washing liquid in said water container has reached a predetermined level and stopping said timing means, said timing means indicating a sensed time representative of a sensed volume of washing liquid admitted to said spin tub during said sensing rinse phase,
vi) operate said draining means to cause extraction of washing liquid and detergent from said water container and commencing a further washing liquid and detergent extraction phase of said washing cycle by rotating said spin tub at a second speed to centrifugally extract washing liquid and detergent from said load,
vii) commence a further rinse phase by operating said washing liquid admission means to cause a predetermined fraction of said sensed volume of said washing liquid to be admitted to said spin tub,
viii) rotate said spin tub at a third spin speed to centrifugally extract washing liquid and detergent from said load, and
ix) commence further rinse and spin phases utilising a predetermined fraction of said sense volume of said washing fluid until the end of said washing cycle.
The invention consists in the foregoing and also envisages constructions of which the following gives examples.
BRIEF DESCRIPTION OF THE DRAWINGS
One preferred form of the present invention will now be described with reference to the accompanying drawings in which;
The invention consists in the foregoing and also envisages constructions of which the following gives examples only.
The invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a partially cut away perspective view of a laundry washing machine adapted to carry a washing cycle according to the method of the present invention, and
FIG. 2 is a flow chart according to the present invention setting for operating the washing machine of FIG. 1 during a washing cycle.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, a top-loading laundry washing machine 1 is shown having a cabinet 2, a hinged lid 3 and a control panel 4 with a series of buttons to allow user input to various parameters controlling the washing cycle of the machine 1. Hot and cold water valves 13 and 14 (which are preferably proportional valves) are connected to hot and cold water taps (not shown) allow water to enter the machine through a spray nozzle (not shown) which is positioned near the upper rim of spin tub 6 to direct water in a defined pattern within the spin tub. A stationary water container 5 is suspended within cabinet 2 from an upper part of the cabinet by suspension rods (not shown). Within the stationary water container 5, a rotatable spin tub 6 is positioned coaxially with water container 5, with a shaft 7 passing through the base of spin tub 6. Spin tub 6 is axially slidable on shaft 7 while, within the base of water container 5, a single pair of sealed bearings 8 are provided in which the shaft turns. The bearings 8 are protected from the washing liquid by a lip seal mounted above them to prevent washing liquid contacting the bearings.
The spin tub is adapted to receive a load of laundry for washing and is provided with a number of holes in its walls to allow water to pass from the spin tub to the water container 5. The lower end of shaft 7 is connected directly to the rotor of an electric motor which is preferably an Electronically Commutated Motor (ECM) of an "inside-out" design (the rotor being external to the stator) with the stator fixed to the base of water container 5. The upper splined end of shaft 7 is fixed within the base of an agitator 10 so that the agitator will always rotate with the motor 9 and shaft 7. The washing machine 1 is supplied with power by through a standard mains voltage supply cord (not shown) connected to a mains voltage supply. A drain pump (not shown) is provided to discharge water held in the water container at various stages during the washing cycle.
Within the base of spin tub 6 are a number of downwardly open air filled spaces 11 which, when water is admitted through valves 13 and/or 14 to the water container 5, provide an upwardly directed buoyancy force to the spin tub 6. When the water container is substantially empty of water, the spin tub and shaft 7 are connected together for movement by the motor 9 due to a dog clutch 12. When the upwardly directed buoyancy force is sufficient to overcome the downwardly directed weight force of the spin tub and clothes load, the spin tub will float upwardly on the shaft 7, disconnecting the oppositely opposed teeth of dog clutch 12 (one set of teeth on the shaft and one set of teeth in the base of spin tub 6) so that the spin tub will not rotate with the agitator. Thus, when a washing phase of a laundry cycle is being carried out and the clothes load are submerged, the agitator is oscillated back and forth independently of the spin tub to wash the clothes. During a spin phase of the washing cycle, the water container will be substantially empty of water and, accordingly, the agitator and spin tub will be rotated together at a high speed.
A controller, for example programmed controller or microprocessor 15 is provided to control the operation of the washing machine in accordance with the method of the present invention. The controller 15 has inputs connected to various sensors such as a water level sensor 16 comprising, for example, a pressure transducer receiving input of water level from tube 17 having its lower end connected to an open bottomed pressure chamber moulded in the plastic water container 5. User inputs of washing parameters such as water level, wash type selection (for example regular, heavy duty or delicate) are also supplied to controller 15 which executes a computer software program stored in memory associated with the controller and in turn supplies outputs to control various functions of the washing machine, such as opening and closing water valves 13 and/or 14, operating the drain pump, supplying commutation voltages to the stator windings of motor 9 to cause the rotor to operate in a predetermined pattern (for example, agitate or spin) and illuminating light emitting diodes (LED's) on control panel 4 to alert the user of the machine to the washing cycle selected and the progress of the washing cycle.
With reference now to FIG. 2, a flow chart is shown which illustrates the steps carried out by the washing machine 1 during a washing cycle in response to the execution of computer software by controller 15.
In use, the washing machine 1 is turned on by a user, initiating the process set out in FIG. 2 starting at block 30. The user loads the spin tub with the clothes load to be washed, adds an amount of detergent to the spin tub and then supplies information to the controller 15 in block 31, such as the water level required to wash the clothes load and the wash cycle required (for example, regular or heavy duty), water temperature and initiates the wash cycle by pressing a start button on control panel 4. Controller 15 then admits water to the spin tub at block 32 by operating valves 13 and/or 14 in appropriate proportions so that the water being directed at the clothes load by the spray nozzle is substantially at the temperature set by the user.
The water level within the water container is monitored until the desired water level is achieved at which time the water inlet valves 13 and/or 14 are closed and motor 9 is supplied with a commutation pattern to oscillate the agitator to wash the clothes load at block 33. The agitation pattern is designed to cause the agitator velocity to follow a predetermined velocity profile through each agitation "stroke", the magnitude and duration of which is dependent on the type of cycle selected (for example, heavy duty or regular) and periodically reversed to change the direction of rotation of agitator 10. The length of the washing/agitation phase may be, for example 12 minutes for a regular cycle and 15 minutes for a heavy duty cycle.
At the end of the wash/agitate phase, the drain pump is operated at block 34 to discharge the water/detergent/soil mixture (washing liquid) from water container 5. When nearly all of the washing fluid within water container 5 has been drained, as signalled by water level sensor 16 detecting that the water level has fallen below the lowest level of pressure chamber 20. After a period of time, for example 8 seconds, to allow the water below the pressure chamber's lower level to be drained, the motor is operated at block 35 to rotate the spin tub and agitator at a high speed to centrifugally extract a further amount of washing liquid from the clothes load. This first spin may, for example, be a short spin of about 2 minutes duration at a rotational velocity of, for example, 200 revolutions per minute (RPM).
At this point in the washing cycle, a number of rinses are carried out during which the spin tub is rotated at a speed of, for example 50 RPM, the water inlet valves are opened and the drain pump operated to extract washing liquid passing through the clothes load. The rinses are interspersed with further spin phases in order to further extract washing liquid from the clothes load. The exact number of rinse phases may be user selectable, the following description being one preferred example only.
The first rinse (or so called "sense rinse") is carried out at block 36 and involves admitting water to the spin tub (preferably directed at the clothes load which, after a spin phase will be distributed in a substantially triangular in cross-section region between the spin tub wall and base) while slowly rotating the spin tub and agitator so that all of the clothes load is wetted. Water is continually added to the clothes load until the water level sensor 16 first detects the water level.
The volume of water admitted to the spin tub during the sense rinse is ascertained by the controller 15. As the volume flow rate can be assumed constant, the volume admitted to the spin tub 6 can be represented by the length of time that the water valves were held open by the controller. This period may be monitored by a timer within controller 15 throughout the execution of the software program and the result (the Sensed Time or ST which represents the Sensed Water Volume or SWV) stored by the controller as a variable for later use by the software. The SWV is a value which may be considered as the sum of the volume of water required to completely saturate the present clothes load plus a volume of water which the clothes load lies in. It should be noted that the value of SWV will be dependent on the size of the clothes load being washed as some of the water will be absorbed by and held within the clothes load. Therefore the actual amount of water required to totally saturate the clothes load is a fraction of SWV. At the conclusion of the sense rinse a second spin phase is initiated at block 37 at, for example, 600 RPM for a duration of, for example, 2 minutes.
A second rinse phase is commenced at block 38 with the spin tub and agitator being rotated together at a speed of, for example, 50 RPM. Water valves 13 and/or 14 are opened to allow an amount of water to de directed at the clothes load, dependent on the sensed water volume (SWV). The volume of water used in this second rinse will be a fraction of the value of SWV (for example, 50% of SWV, 75% of SWV, 100% of SWV or any fraction from 50% to 100%) and this value could be set by the user. In order to supply the selected fraction of SWV to the clothes load within spin tub 6, controller 15 may, for example, time the admission of water to the spin tub and close valves 13 and/or 14 when the timer reaches the determined time (for example, 75% of ST). When the second rinse phase has been completed, a third spin phase is initiated at, for example, 600 RPM for a period of, for example, 2 minutes.
A third rinse phase is then carried out at block 40 using a water volume also dependent on the value of SWV. The volume used in the third rinse could be the same as for the second rinse, however, a different fraction of SWV (or, in reality a fraction of the sensed time ST) could alternatively be used. At block 40, a fourth spin phase is carried out at a spin speed of, for example, 1000 RPM for a duration of, for example, 2 minutes. A fourth me phase is conducted at block 42 using a fraction of the water volume determined in block 36. Again the fraction could, for example, be 75% of SWV (or the duration of the sense rinse could be 75% of the sensed time ST) or any other fraction.
The washing cycle is concluded by a final spin at block 43 at a spin speed of, for example, 1000 RPM for a duration of, for example, 6 minutes. At the end of the final spin, the clothes load will be free of much of the water added during the washing cycle and in a reasonable state of dryness, ready to be dried.
Alternatively, rather than a fixed member of rinse and spin phases being carried out after the sense rinse at block 36, the washing machine could be provided with a washing liquid quality sensor 21 (such as a turbidity sensor or a resistivity sensor) transmitting washing fluid quality information to controller 15. The washing cycle could end when sufficient rinse and spin phases have been carried out that the washing liquid quality sensor determines that the washing liquid quality has reached a predetermined quality (sufficient soil and detergent having been removed from the clothes load and washing liquid). In this case, a final high speed spin would be carried out after the water quality was determined to be acceptable.
The present invention, by doing away with a conventional "deep rinse" phase in which the clothes load is submerged in a large quantity of fresh water in order to remove detergent, results in lower water consumption by the washing machine. In addition, the "sense rinse" process determines the minimum quantity of water which is required to totally wet the clothes load, so that water is not wasted during rinsing, thereby improving the efficiency of the machine at rinsing the clothes load. | A laundry washing machine in which water is conserved by replacing the conventional deep rinse by a series of spray rinses. Each spray rinse utilises a predetermined quantity of water which is sprayed directly at the clothes load while the load is rotated, thereby allowing the rinse water to pass straight through the clothes load, removing soil and/or detergent from the clothes on its way. The amount of water used in each spray rinse is determined from a first "sense rinse" cycle in which the volume of water required to totally saturate the clothes load is found. In each subsequent rinse, a proportion (preferably from about 50% to about 100%) of this value is used. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 62/069,038 filed Oct. 27, 2014, which is incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to hunting blinds for use by hunters or outdoorsmen. More specifically, the present invention relates to hunting blinds with tool-less hubs and attachment mounts.
BACKGROUND OF THE INVENTION
[0003] Outdoorsmen such as hunters, nature observers, bird watchers, photographers, etc. usually prefer to remain hidden from the wildlife that they are hunting or studying. Hunting blinds are devices that cover and conceal a hunter to reduce the likelihood of detection. Early examples of hunting blinds include the cocking-cloth, a canvas and stick device that allowed hunters to approach pheasants. While early hunting blinds were relatively simple in design, modern hunting blinds may be very complex and approach the size of a small house. Larger hunting blinds may be ground level or elevated, but larger blinds tend to be permanent in their location.
[0004] Some modern hunting blinds are mobile in nature and collapsible to a smaller size for easy transport. This allows a hunter to set up the hunting blind in an unlimited number of locations in contrast to the single location of the larger blinds. These hunting blinds typically consist of a camouflage cover and a support structure that is designed for rapid deployment and take down. Some mobile hunting blinds utilize a hub system that allows a hunter to easily collapse and open the hunting blind. Examples of these hub systems may be found in U.S. Pat. Nos. 5,628,338; 6,296,415; 7,594,514; 8,578,956; and U.S. Patent Publication Nos. 2013/0174826 and 2013/0180559; which are hereby incorporated by reference in their entirety. Once the hunting blind is erected, the outdoorsman typically enters through a “door” that is defined in the cover.
[0005] The hub system generally comprises a central hub with poles extending outward from the hub. The ends of the poles are typically fixed to the corners of the blind. In a collapsed state, the poles are generally parallel to one another, and the fabric of the blind is loose. In an opened state, the poles spread out from one another until the poles and hub lie in a common plane. The hub continues to extend outward and “pops” into place such that the fabric of the blind is taught and extends outward and away from the center of the hunting blind to provide the hunter with additional room.
[0006] One issue with hunting blinds is that tools are required when there is a maintenance issue with the hub system, and there are a variety of possible maintenance issues. For example, the joints between the hub and the poles may become dirty or defective, and because most poles are fiberglass, the poles are prone to breaking. Natural causes such as high winds, snow weight, falling limbs, etc. can break poles, and unnatural causes such as human error or accidents can break poles. Further, components of the poles such as the ears or protrusions often break when the hub is assembled and disassembled.
[0007] Opening the hub to remove a broken pole or otherwise repair the system requires a tool such as a screwdriver or wrench. The tool requirement of prior art hub systems is a weight burden for the hunter as hunters will hike considerable distance to set up a hunting blind, and every pound of weight matters. The tool requirement is also an easy oversight for the hunter during preparation for the hunt. Further, when working on a hub during a hunt or other activity, an outdoorsman may lose a component such as a washer or nut, especially when working on the blind in the dark (which is common when hunting), which can prevent the hunting blind from working properly. Having a defective hunting blind and no tool to repair the hub system can ruin a hunt.
[0008] A further issue with prior art hubs is that they lack integrated feature for attaching accessories. Prior art devices may be used to mount accessories. However, these devices require additional time, hardware and space to get them set up inside the blind. Further, these devices require the outdoorsman to remove them each and every time the blind is taken down. Therefore there is a need for an accessory mount that is capable of remaining attached to the blind when the blind is collapsed and stored away.
SUMMARY OF THE INVENTION
[0009] It is thus an aspect of embodiments of the present invention to provide a tool-less hub for a hunting blind where poles are easily replaced without disassembly of the hub. It is a further aspect of embodiments of the present invention to improve the usability of a hunting blind with the addition of an accessory mount that may be integrated with the hub of the blind.
[0010] It is one aspect of embodiments of the present invention to provide a tool-less hub that does not require any tools to change poles out of the hub. Some embodiments of the present invention accomplish the tool-less design by defining a pair of protrusions on the end of a pole. The protrusions have a generally circular profile, but the circular shape is truncated such that the protrusions have a flat top side and a flat bottom side. The flat sides must be aligned with pass-through channels in the hub for a user to insert or remove the pole from the hub. When the protrusions pass through the pass-through channels and into rotation channels, the pole may freely rotate. Once the pole rotates and the flat sides of the protrusions are no longer aligned with the pass-through channels, the pole is effectively locked in the hub.
[0011] It is another aspect of embodiments of the present invention to provide a tool-less hub that comprises an additional locking mechanism. In the above embodiment, it is possible that the pole may rotate to a specific angle where the flat sides of the protrusions align with the pass-through channels, and the pole may accidentally fall out of the hub. Thus, some embodiments of the present invention may comprise a deflectable protrusion positioned on the hub where a user must overcome a predetermined force to press the deflectable protrusion into the body of the hub and align the flat sides of the pole protrusions with the pass-through channels. The additional force makes accidental pole removals much less likely. In various embodiments, the hub may not have a pass-through channel. Rather, the pole protrusions may deflect into the body of the pole itself. A user may toggle a button or simply press the protrusions into the hub to deflect the pole protrusions. Once the pole protrusions reach the rotation channels, they extend outward, and the pole may freely rotate without risk of accidental pole removal.
[0012] It is a further aspect of embodiments of the present invention to provide an accessory mount to attach a variety of accessories to a hub or other similar device. In some embodiments, the accessory mount may comprise an extension body and an articulating body that are joined together with a ball-and-socket joint. This joint may be locked when an adjuster is screwed into the articulating body and the socket portion of the joint closes in on the ball portion of the joint, and the positions of the extension body and the articulating body are locked relative to each other. The extension body may be selectively interconnected to a hub or other object, and the articulating body may be interconnected to an accessory. Thus, the position and/or orientation of the accessory may be manipulated then locked into place. In other embodiments, the position and orientation of the accessory cannot necessarily be manipulated once the accessory and accessory mount are attached to the hub. One skilled in the art will appreciate a variety of combinations of couplers, extension bodies, articulating bodies, adapters, and other components as discussed elsewhere herein.
[0013] One particular embodiment of the present invention is a tool-less hub for a tent structure that utilizes a plurality of poles, comprising a hub having at least one pole dock which at least partially defines a partially enclosed volume, the at least one pole dock comprising at least one rotation channel; at least one pole having at least one protrusion disposed on one end of the at least one pole, wherein the at least one protrusion is disposed in the at least one rotation channel when the one end of the at least one pole is disposed in the partially enclosed volume, and wherein the at least one pole is rotatable relative to the hub.
[0014] Another particular embodiment of the present invention is an accessory mount comprising an extension body having a first end and a second end, wherein the second end is a ball-shaped end; an articulating body having a third end and a fourth end, wherein the third end is a socket-shaped end, wherein the ball-shaped end is insertable into the socket-shaped end to form a ball-and-socket joint, the articulating body also comprising an adjuster aperture; an adjuster having a threaded shaft that operatively interconnects to the adjuster aperture, and engagement of the adjuster locks the ball-and-socket joint and fixes the extension body and the articulating body relative to each other; wherein the first end is configured to selectively interconnect to a hub, and the fourth end is configured to selectively interconnect to an accessory.
[0015] Yet another particular embodiment of the present invention is a coupler for a hub, comprising a rod having a threaded outer surface; a first end having a inner surface, wherein at least a portion of the inner surface is threaded to match the threaded outer surface of the rod; wherein the rod is threaded into an axial thread of a hub to secure at least two components of the hub.
[0016] One embodiment of the present invention is a system for articulating an adapter in three dimensions relative to a hunting blind, comprising a hub adapted for interconnection to hunting blind; a coupler selectively interconnected to the hub; an articulating body having a first end and a second end, the first end of the articulating body interconnected to the coupler to form a first joint, wherein a first adjuster is configured to selectively lock the first joint; and an adapter interconnected to the second end of the articulating body to form a second joint, wherein a second adjuster is configured to selectively lock the second joint.
[0017] The coupler may also comprise several components. For example, the coupler may comprise a rod and an end selectively interconnected to the rod. The rod of the coupler may comprise a threaded outer surface, and the hub of the hunting blind comprises a threaded recess, wherein the rod is operably engaged to the recess to selectively interconnect the coupler to the hub.
[0018] The articulating body may form joints with other components that allow articulating in one or more dimensions. For example, the first joint may be a ball-and-socket joint, and the first end of the articulating body is a socket portion of the ball-and-socket joint of the first joint, wherein the first end of the articulating body defines a first partially enclosed volume. The first adjuster may be configured to compress the first end of the articulating body to a second reduced partially enclosed volume to selectively lock the first joint. The second joint may be a ball-and-socket joint, and the second end of the articulating body is a socket portion of the ball-and-socket joint of the second joint, wherein the second end of the articulating body defines a first partially enclosed volume. The second adjuster may be configured to compress the second end of the articulating body to a second reduced partially enclosed volume to selectively lock the second joint. The first joint may be a ball-and-socket joint, and wherein the coupler further comprises an extension body, and one end of the extension body is a ball portion of the ball-and-socket joint of the first joint. The second joint may be a ball-and-socket joint, and wherein the adapter comprises an adapter head that is a ball portion of the ball-and-socket joint of the second joint.
[0019] The adapter may be associated with different accessories. For example, an accessory may be selectively interconnected to the adapter, wherein the accessory is one of a camera, a video recorder, a light, a portable electronic device, a scent dispenser, a firearm, a tray, a bow holder, a cross bow holder, a gun holder, and a game call.
[0020] Another embodiment of the present invention is an accessory mount adapted to secure an accessory in a predetermined location, comprising an extension body having a distal end and a proximal end, wherein the proximal end comprises a substantially ball-shaped end; an articulating body having a first end and a second end, wherein the first end is a socket-shaped end, wherein the ball-shaped end of the extension body and the socket-shaped first end of the articulating body form a ball-and-socket joint, the articulating body also comprising an adjuster aperture; an adjuster having a threaded shaft that operatively engages the adjuster aperture, and the operable engagement of the adjuster locks the ball-and-socket joint of the extension body and the articulating body and fixes the extension body and the articulating body relative to each other to secure said ball and socket in a specific location; and wherein the second end of the articulating body is configured to selectively interconnect to an adapter, which is adapted to secure an accessory.
[0021] The extension body may also comprise a coupler with several components. For example, the extension body may comprise a coupler configured to selectively interconnect to a hub. The coupler may comprise a rod having a threaded outer surface; a first end having a inner surface, wherein at least a portion of the inner surface of the first end is threaded to match the threaded outer surface of the rod; and wherein the rod is operably engaged with a threaded recess of the hub to selectively interconnect the coupler to the hub. The coupler may further comprise a second end having an inner surface, wherein at least a portion of the inner surface of the second end is threaded to match the threaded outer surface of the rod.
[0022] The accessory mount may also comprise an adapter. For example, an adapter may have a ball-shaped adapter head, wherein the second end of the articulating body is a socket-shaped end, and wherein the ball-shaped adapter head and the socket-shaped second end of the articulating body form a ball-and-socket joint. In addition, a second adjuster may have a threaded shaft that operably engages a second adjuster aperture in the articulating body, and the operable engagement of the second adjuster locks the ball-and-socket joint of the adapter and the articulating body and fixes the adapter and the articulating body relative to each other. An accessory may be selectively interconnected to the adapter, wherein the accessory is one of a camera, a video recorder, a light, a portable electronic device, a scent dispenser, a firearm, a tray, a bow holder, a cross bow holder, a gun holder, and a game call. The articulating body may comprise a slit that extends to the socket-shaped first end of the articulating body, wherein the operably engagement of the adjuster compresses the slit and the socket-shaped first end of the articulating body to lock the ball-and-socket joint of the extension body and the articulating body and fix the extension body and the articulating body relative to each other. The articulating body may form an articulation angle between the first end and the second end, wherein the articulation angle is between approximately 30 and 60 degrees.
[0023] One embodiment of the present invention is an accessory mount for articulating an adapter in three distinct dimensions relative to a hunting blind, comprising a coupler configured to selectively interconnect to a hub of a hunting blind, the coupler comprising: (a) a rod having a threaded outer surface; (b) a first end having a inner surface, wherein at least a portion of the inner surface is threaded to match the threaded outer surface of the rod, wherein the rod is operably engaged to a recess of the hub to selectively interconnect the coupler to the hub; (c) a second end having an inner surface, wherein at least a portion of the inner surface is threaded to match the threaded outer surface of the rod; an extension body having a distal end and a proximal end, wherein the distal end is interconnected to the coupler, and wherein the proximal end is a ball-shaped end; an articulating body having a first end and a second end, wherein the first end is a socket-shaped end, wherein the ball-shaped proximal end of the extension body and the socket-shaped first end of the articulating body form a ball-and-socket joint, the articulating body comprises a first adjuster aperture; a first adjuster having a threaded shaft that operatively engages to the first adjuster aperture, and the operable engagement of the first adjuster locks the ball-and-socket joint of the extension body and the articulating body and fixes the extension body and the articulating body relative to each other; an adapter having a ball-shaped adapter head, wherein the second end of the articulating body is a socket-shaped end, and wherein the ball-shaped adapter head and the socket-shaped second end of the articulating body form a ball-and-socket joint, the articulating body comprises a second adjuster aperture; a second adjuster having a threaded shaft that operably engages the second adjuster aperture in the articulating body, and the operable engagement of the second adjuster locks the ball-and-socket joint of the adapter and the articulating body and fixes the adapter and the articulating body relative to each other; and wherein an accessory is selectively interconnected to the adapter, wherein the accessory is one of a camera, a video recorder, a light, a portable electronic device, a scent dispenser, a firearm, a tray, a bow holder, a cross bow holder, a gun holder, and a game call.
[0024] These and other advantages will be apparent from the disclosure of the invention(s) contained herein. The above-described embodiments, objectives, and configurations are neither complete nor exhaustive. The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. Moreover, references made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and Detailed Description and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detailed Description particularly when taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the general description of the disclosure given above and the detailed description of the drawings given below, serve to explain the principles of the disclosures.
[0026] FIG. 1 is an isometric view of a prior art hub having an eyelet;
[0027] FIG. 2 is an isometric view of a tool-less hub according to one embodiment of the present invention;
[0028] FIG. 3 is an isometric view of a pole comprising a protrusion according to one embodiment of the present invention;
[0029] FIG. 4 is an isometric view of a tool-less hub comprising four poles according to one embodiment of the present invention;
[0030] FIG. 5 is a bottom plan view of the tool-less hub and four poles of the embodiment in FIG. 4 ;
[0031] FIG. 6 is a right elevation view of the tool-less hub and four poles of the embodiment in FIG. 4 ;
[0032] FIG. 7 is an isometric view of a top side of an accessory mount according to one embodiment of the present invention;
[0033] FIG. 8 is an isometric view of a bottom side of the accessory mount of FIG. 7 ;
[0034] FIG. 9 is an isometric view of a coupler of an accessory mount according to one embodiment of the present invention;
[0035] FIG. 10 is an isometric view of an extension body of an accessory mount according to one embodiment of the present invention;
[0036] FIG. 11 is an isometric view of an articulating body of an accessory mount according to one embodiment of the present invention;
[0037] FIG. 12 is a top plan view of the articulating body of FIG. 11 ;
[0038] FIG. 13 is a right elevation view of the articulating body of FIG. 11 ;
[0039] FIG. 14 is an isometric view of a top side of an adapter of an accessory mount according to one embodiment of the present invention;
[0040] FIG. 15 is an isometric view of a bottom side of an adapter of an accessory mount according to one embodiment of the present invention;
[0041] FIG. 16 is an isometric view of a top side of an adjuster of an accessory mount according to one embodiment of the present invention;
[0042] FIG. 17 is an isometric view of a bottom side of an adjuster of an accessory mount according to one embodiment of the present invention; and
[0043] FIG. 18 is an isometric view of a tree screw according to one embodiment of the present invention.
[0044] To assist in the understanding of the embodiments of the present invention the following list of components and associated numbering found in the drawings is provided herein:
[0000]
Component
No.Component
2
Hub
4
First Pole Dock
6
Second Pole Dock
8
Third Pole Dock
10
Fourth Pole Dock
12
Pass-Through Channel
14
Rotation Channel
16
Channel Height
18
Channel Width
20
Pole Indicator
22
Axial Thread
24
First Pole
26
Protrusion
28
Second Pole
30
Third Pole
32
Fourth Pole
34
Accessory Mount
36
Coupler
38
Extension Body
40
Articulating Body
42
Adapter
44
First Adjuster
46
Second Adjuster
48
Rod
50
First End
52
Second End
54
Interface End
56
Extension Shaft
58
Extension Head
60
First Socket
62
Slit
64
Adjuster Aperture
66
Second Socket
68
Adapter Head
70
Notch
72
Mount End
74
Adjuster Shaft
76
Adjuster Head
78
Tree Screw
80
First Section
82
Second Section
84
Handle
[0045] It should be understood that the drawings are not necessarily to scale, and various dimensions may be altered. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION
[0046] The present invention has significant benefits across a broad spectrum of endeavors. It is the Applicant's intent that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed. To acquaint persons skilled in the pertinent arts most closely related to the present invention, a preferred embodiment that illustrates the best mode now contemplated for putting the invention into practice is described herein by, and with reference to, the annexed drawings that form a part of the specification. The exemplary embodiment is described in detail without attempting to describe all of the various forms and modifications in which the invention might be embodied. As such, the embodiments described herein are illustrative, and as will become apparent to those skilled in the arts, may be modified in numerous ways within the scope and spirit of the invention.
[0047] Although the following text sets forth a detailed description of numerous different embodiments, it should be understood that the detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term by limited, by implication or otherwise, to that single meaning.
[0048] Various embodiments of the present invention are described herein and as depicted in the drawings. It is expressly understood that although the figures depict hubs, poles, and accessory mount components, the present invention is not limited to these embodiments.
[0049] Now referring to FIG. 1 , a prior art hub is shown. This hub comprises four locations to dispose poles. Further, the hub comprises a two-piece design that is held together with a bolt that has an eyelet disposed on one end and a nut disposed on the reverse side. If a pole breaks in this prior art design, a user must have a tool to remove the bolt and disassemble the multi-part hub.
[0050] Now referring to FIG. 2 , a tool-less hub 2 of the present invention is provided. The tool-less hub 2 has a first pole dock 4 , a second pole dock 6 , a third pole dock 8 , and a fourth pole dock 10 . The first pole dock 4 has an inner surface that defines a partially enclosed volume. A first pole (shown in FIG. 2 ) is insertable to and removable from the partially enclosed volume of the first pole dock 4 . A pass-through channel 12 is disposed on an inner surface of the first pole dock 4 . In this embodiment, the pass-through channel 12 is a straight line oriented perpendicular to the small dimension, or height dimension, of the hub 2 . A first end of the pass-through channel 12 is positioned at the outer surface of the hub 2 , and the pass-through channel 12 extends toward the center of the hub 2 to a second end of the pass-through channel 12 . One skilled in the art will appreciate a pass-through channel 12 that has shapes beyond a straight line. For example, the pass-through channel 12 may comprise one or more radii between its two ends. Further, the pass-through channel 12 may comprise an nth order polynomial shape, a “V” shape, a “W” shape, or any other shape commonly known in the art.
[0051] A rotation channel 14 is disposed at the second end of the pass-through channel 12 . In the embodiment illustrated in FIG. 2 , the rotation channel 14 is a circular shape such that a protrusion having a radius could freely rotate within the rotation channel 14 . The rotation channel 14 may have a conical profile wherein the rotation channel 14 is circular at the inner surface of the first pole dock 4 but tapers down further into the wall of the first pole dock 4 . The pass-through channel 12 may also have a similar tapering profile. One skilled in the art will appreciate a variety of channel profiles including, but not limited to, conical, truncated conical, stepped, countersunk, and flat (which is depicted in FIG. 2 with a channel height 16 and a channel width 18 ).
[0052] In the embodiment shown in FIG. 2 , the first pole dock 4 is bilaterally symmetric, meaning the pass-through channel 12 and the rotation channel 14 are mirrored on the opposite side of the inner surface of the first pole dock 4 . One skilled in the art will appreciate that the present invention is not limited to bilaterally symmetric embodiments. For example, some embodiments may have a shorter/longer pass-through channel 12 , a smaller/larger rotation channel 14 , or the first pole dock 4 may only comprise one set of pass-through and rotation channels 12 , 14 . Accordingly, embodiments of the pole may only have one protrusion (shown in FIG. 3 ).
[0053] Located on the side of the first pole dock 4 is a pole indicator 20 , which is an aperture that extends through the first pole dock's 4 wall so that a user may see the first pole dock's 4 partially enclosed volume from the outside of the hub 2 . When a user inserts a first pole (shown in FIG. 2 ) into the first pole dock 4 , the user can see the first pole through the pole indicator 20 to ensure the first pole is in the proper position. At this point, the user may rotate the first pole to secure the first pole in the rotation channel 14 . The embodiment shown in FIG. 2 has one pole indicator 20 per pole dock. However, one skilled in the art will appreciate embodiments with more than one pole indicator 20 per pole dock or no pole indicators 20 per pole dock. Further, pole indicators 20 may be disposed on any surface of the pole dock.
[0054] Next, the hub 2 depicted in FIG. 2 has four pole docks 4 , 6 , 8 , 10 arranged symmetrically about a longitudinal axis of the hub 2 . The pole docks 4 , 6 , 8 , 10 are offset to one side to create a central portion of the hub 2 where an axial thread 22 is disposed, where the axial thread 22 is oriented parallel with the longitudinal axis of the hub 2 . As will be discussed in further detail below, the central portion of the hub 2 and/or the axial thread 22 may provide a location to interconnect accessories and other objects. The central portion of the hub 2 may optionally include the axial thread 22 . In other embodiments, the central portion of the hub 2 may comprise a protruding male thread, snap fastener half, zipper half, or any other means of interconnecting two objects. The hub 2 may have a female connector on one side and a male connector on the other side, two female connectors, two male connectors, or no connectors.
[0055] The hub 2 may be made from a variety of materials including, but not limited to, molded polymers, carbon fiber, die cast aluminum, any alloys via a metal injection molding process, or any other materials commonly known in the art.
[0056] In some embodiments, the pole docks 4 , 6 , 8 , 10 may be even further offset to completely eliminate the central portion of the hub 2 . In yet further embodiments, the pole docks 4 , 6 , 8 , 10 may be centered—i.e., not offset—which provides a larger central portion of the hub 2 than depicted in FIG. 2 . One skilled in the art will appreciate that embodiments of the present invention may comprise one, two, three, four, or more pole docks that may or may not be evenly spaced about the longitudinal axis of the hub 2 .
[0057] Now referring to FIG. 3 , a detailed view of the first pole 24 and protrusion 26 is shown along with the pass-through channel 12 of the pole dock 4 . The pass-through channel 12 is similar to the pass-through channel 12 shown in FIG. 2 where the pass-through channel 12 has a channel height 16 and a channel width 18 . The protrusion 26 extends laterally from the body of the first pole 24 to match the channel width 18 of the pass-through channel 12 , and the protrusion 26 end has a flat surface. When viewed from the side, the protrusion 26 has a truncated shape, meaning the shape has a radius but has been flattened on a top side and a bottom side. The distance between these two flat sides matches the channel height 16 . The amount of the circle that has been truncated can be expressed in terms of percentage of circle truncated. In one embodiment, between approximately 50% and 80% of the circle shape has been truncated. In another embodiment, between approximately 60% and 70% of the circle shape has been truncated. One skilled in the art will appreciate that the top side and bottom side of the protrusion are not necessarily flat, and the two truncated portions (top side and bottom side) are not necessarily equal in area.
[0058] With the length of the first pole 24 oriented perpendicular to the longitudinal axis of the hub 2 , the shape of the protrusion 26 aligns with the pass-through channel 12 , and the first pole 24 is insertable into the first pole dock 4 . Once the protrusion 26 reaches the rotation channel 14 , the first pole 24 may freely rotate and is locked in the rotation channel 14 .
[0059] Now referring to FIGS. 4-6 , a hub 2 is shown with the first pole 24 , the second pole 28 , the third pole 30 , and the fourth pole 32 positioned proximate to their respective pole docks 4 , 6 , 8 , 10 . The fourth pole 32 is oriented perpendicular to the longitudinal axis of the hub 2 so that the fourth pole 32 is insertable into the fourth pole dock 10 . The second pole 28 is also oriented perpendicular to the longitudinal axis of the hub 2 , but the protrusions of the second pole 28 have passed through the pass-through channel and into the rotation channel. The first pole 24 and the third pole 30 show that once the pole protrusions pass through the pass-through channel and are disposed in the rotation channel, the poles are free to rotate. The poles 24 , 28 , 30 , 32 may be made from a variety of materials including, but not limited to, molded polymers, carbon fiber, die cast aluminum, any alloys via a metal injection molding process, or any other materials commonly known in the art. Further one skilled in the art will appreciate other embodiments, where the poles 24 , 28 , 30 , 32 are segmented into multiple pieces such that a pole 24 , 28 , 30 , 32 may be threadably interconnected to a rotating portion that is already interconnected to the pole docks 4 , 6 , 8 , 10 on the hub 2 . Poles 24 , 28 , 30 , 32 may also comprise ball-and-socket joints or any other joints at any position on the poles 24 , 28 , 30 , 32 .
[0060] In other embodiments of the present invention, the poles 24 , 28 , 30 , 32 may not comprise fixed protrusions, and the pole docks 4 , 6 , 8 , 10 may not comprise pass-through channels. In these embodiments, the protrusions have the ability to retract into the body of the pole. A button disposed on the pole may be operatively interconnected to the retractable protrusions, and the button has a first position and a second position. When the button is in a first position, the protrusions are retracted into the body of the pole. The user may directly insert the pole proximate to the rotation channel. When the pole is in this position, the user may move the button to a second position such that the protrusions extend from the body of the pole. The protrusions match the rotation channel, and the pole is free to rotate within the dock.
[0061] In yet further embodiments, the protrusions are simply deflectable into the body of the pole. The protrusions may comprise a flange and spring system such that the protrusions are biased outward in a default state. A user may press the end of the pole into the pole dock such that the protrusions overcome their bias and deflect into the body of the pole. The pole dock may comprise ramps or other similar shapes such that the deflection of the protrusions is gradual. Once the end of the pole is positioned proximate to the rotation channel, the protrusions are allowed to extend outward again, and the pole is free to rotate within the pole dock.
[0062] The pole docks 4 , 6 , 8 , 10 may also comprise features that aid a user in deploying the hub 2 without any tools. For example, a deflectable protrusion may be positioned proximate to the first end of the pass-through channel, which is the outer surface of the pole docks 4 , 6 , 8 , 10 . As a user aligns the flat sides of the protrusions with the pass-through channel and begins to insert the pole into the pole dock. The deflectable protrusion deflects into the body of the pole dock such that the pole may pass through the pass-through channel. Once the pole protrusions reach the rotation channel and the user rotates the pole, the deflectable protrusion extends outward. With this feature, additional force is required to deflect the deflectable protrusion and align the flat sides of the pole protrusions with the pass-through channel before removing the pole from the pole dock. This helps prevent accidental alignment of the flat sides of the pole protrusions with the pass-through channel and accidental removal of the pole from the pole dock. One skilled in the art will appreciate that this deflectable protrusion may be placed anywhere on the pole dock including, but not limited to, the outer surface of the pole dock, the pass-through channel, the rotation channel, and the inner surface of the pole dock.
[0063] Now referring to FIGS. 7 and 8 , an accessory mount 34 is shown, and the accessory mount 34 comprises a coupler 36 , an extension body 38 , an articulating body 40 , an adapter 42 , a first adjuster 44 , and a second adjuster 46 . The coupler 36 interconnects the accessory mount 34 to an object or device. In some embodiments, the coupler 36 interconnects the accessory mount 34 to the axial thread 22 of the tool-less hub 2 .
[0064] The extension body 38 adds longitudinal distance between the coupler 36 and the remaining components. When the accessory mount 34 is interconnected to a wall or other similar surface, it is beneficial to have an extension body 38 to increase the distance between the remaining components and the wall so that the remaining components may be freely articulated and positioned. In alternative embodiments, a user may desire a shorter distance between the hub 2 and the remaining components. It will be appreciated from the disclosure herein that the term “coupler” may refer to one or both of the coupler 36 and the extension body 38 . Similarly, the term “extension body” may refer to one or both of the coupler 36 and the extension body 38 .
[0065] Next, the extension body 38 is interconnected to an articulating body 40 , which in turn is interconnected to an adapter 42 . Accessories such as cameras, trays, bow holders, lights, scent dispensers, scent elimination systems, etc. may be mounted to the adapter 42 . The extension-articulating and articulating-coupler interconnections are ball-and-socket type interconnections so that the accessory or accessories mounted on the adapter 42 may be positioned and/or oriented in a number of configurations. A first adjuster 44 and a second adjuster 46 are interconnected to the articulating body 40 wherein the first adjuster 44 corresponds to the extension-articulating interconnection, and the second adjuster 46 corresponds to the articulating-coupler interconnection. A user may engage the adjusters 44 , 46 to prevent the extension-articulating and articulating-coupler interconnections from moving. In other words, the first adjuster 44 may fix the positions of the extension body 38 and the articulating body 40 relative to each other. Likewise, the second adjuster 46 may fix the positions of the articulating body 40 and the adapter 42 relative to each other.
[0066] Now referring to FIG. 9 , an isometric view of the coupler 36 is provided. The coupler comprises a rod 48 disposed between a first end 50 and a second end 52 . The rod 48 has a threaded outer surface, which matches threaded inner surfaces of the first end 50 and the second end 52 . A user may remove the second end 52 and thread the rod 48 into the axial thread 22 of the hub 2 or any other threaded recess. One skilled in the art will appreciate other means by which the coupler 36 interconnects to a hub 2 , another object, and/or the extension body 38 (shown in FIG. 10 ).
[0067] In some embodiments of the present invention, the coupler 36 replaces the eyebolt on existing hub designs such that the accessory mount 34 may be used with existing hubs. The coupler 36 may also be used on both the inside and outside of the hub 2 . For example, this provides a user with the ability to attach a bow holder on the inside of the hub 2 and a scent dispenser on the outside of the hub 2 , simultaneously. As mentioned above, embodiments of the present invention contemplate an axial thread 22 disposed on a central portion of the hub 2 along with various other connection means. In embodiments where the axial thread 22 extends through the hub 2 , the coupler 36 does not require a second end 52 as the rod 48 will simply thread into the axial thread 22 .
[0068] The diameter of the rod 48 may be between approximately 1/32″ and 2″. In other embodiments, the rod 48 diameter may be between approximately ⅛″ and ½″. In a preferred embodiment, the rod 48 diameter is approximately ¼″. The two ends 50 , 52 may have a diameter between approximately ⅛″ and 2″. In other embodiments, the ends' 50 , 52 diameters may be between approximately ⅜″ and 1″. In a preferred embodiment, the ends' 50 , 52 diameters are approximately ⅝″. The length of the ends 50 , 52 may be between approximately ⅛″ and 6″. In other embodiments, the ends' 50 , 52 lengths are between approximately ½″ and 2″. In a preferred embodiment, the ends' 50 , 52 lengths are approximately 1″. One skilled in the art will appreciate that these dimensions are only exemplary in nature, and it is not intended that the invention be limited to the above ranges. Further, one skilled in the art will appreciate that the ends 50 , 52 may not be the same size, and in some embodiments, there may be one end, more than two ends, or no ends. The material of the ends 50 , 52 and the rod 48 is aluminum in some embodiments. One skilled in the art will appreciate that the material of the ends 50 , 52 and the rod 48 may be any other material discussed herein or otherwise commonly known in the art. Further still, various surfaces and edges may be knurled, radiused, chamfered, etc.
[0069] Now referring to FIG. 10 , an extension body 38 comprising an extension end 54 , an extension shaft 56 , and an extension head 58 is shown. The extension body 38 provides additional longitudinal distance between the coupler 36 and the remaining components of the accessory mount 34 . The extension end 54 interconnects to the first end 50 or second end 52 of the coupler 36 or directly into the tool-less hub 2 wherein a threaded outer surface of the extension end 54 matches the threaded inner surface of the first end 50 , second end 52 , or tool-less hub 2 . The extension shaft 56 provides the additional longitudinal length for the accessory mount 34 such that articulating components may be positioned and oriented freely. The extension head 58 is disposed on the opposite end of the extension shaft 56 from the extension end 54 . The extension head 58 is a ball-shaped end that interconnects to the articulating body 40 (shown in FIGS. 11-13 ) to form a ball-and-socket joint. One skilled in the art will appreciate other connection types between the extension body 38 and the coupler 36 and between the extension body 38 and the articulating body 40 as discussed elsewhere herein and as commonly known in the art.
[0070] Now referring to FIGS. 11-13 , an articulating body 40 is provided. The articulating body 40 comprises a first socket 60 , a slit 62 that extends from the first socket toward the center of the articulating body 40 , and an adjuster aperture 64 that extends through the articulating body 40 along a lateral axis and through the slit 62 . At least a portion of the first socket 60 defines at least a portion of a spherical volume. The extension head 58 of the extension body 38 may deflect into the spherical volume of the first socket 60 in a ball-and-socket type interconnection. Once the extension head 58 and the first socket 60 are interconnected, the extension body 38 and the articulating body 40 may freely rotate and pivot about each other. A first adjuster 44 may thread through the adjuster aperture 64 on a flattened portion of the articulating body 40 and deflect the slit 62 such that the first socket 60 closes on the extension head 58 , and the extension body 38 and the articulating body 40 are fixed relative to each other. As shown in FIG. 12 , the articulating body 40 is symmetric about a lateral plane, and a second socket 66 operates in much the same way as the first socket 60 .
[0071] The articulating body 40 may have several forms. For example, the articulating body 40 may comprise a crook or bend between the first socket 60 and the second socket 66 that forms an articulation angle. In some embodiments, the articulation angle formed by the bend is between 30 and 60 degrees. The articulation angle can be utilized to allow another component, such as the extension body, to lie flat against the articulating body 40 .
[0072] FIGS. 14 and 15 show an adapter 42 that comprises an adapter head 68 , a plurality of notches 70 , and a mount end 72 . The adapter head 68 is a ball-shaped end that interconnects to the second socket 66 in much the same way as the extension head 58 interconnects to the first socket 60 . The adapter head 68 and the second socket 66 form a ball-and-socket type interconnection. Notches 70 disposes on the adapter 42 help a user manipulate the position and orientation of the adapter 42 . A second adjuster (shown in FIGS. 16 and 17 ) extends through another adjuster aperture, which may close another slit and fix the positions of the articulating body 40 and the adapter 42 relative to each other.
[0073] The adapter 42 also comprises a mount end 72 , which is the portion of the accessory mount 34 that interconnects to the chosen accessory or accessories. In the embodiment shown in FIGS. 14 and 15 , the mount end 72 is a male portion of an interconnection and may be threaded, unthreaded, or otherwise configured to be a portion of an interconnection. In some embodiments, the mount end 72 may be a threaded or unthreaded recess in the adapter 42 . In various embodiments, the mount end 72 may be one portion of a quick locking device. The adapter 42 may simulate any number of devices including, but not limited to, a camera mount, a light mount, a phone mount, a dispenser mount for attractant scents, a scent elimination mount, a bow mount, and a gun mount.
[0074] Now referring to FIGS. 16 and 17 , a first adjuster 44 having an adjuster shaft 74 and an adjuster head 76 is provided. The adjuster shaft 74 comprises a threaded outer surface that matches a threaded inner surface of the adjuster aperture 64 of the articulating body 40 . The adjuster head 76 comprises a shape that is elongated in a lateral direction so that a user may generate torque to screw the first adjuster 44 into the adjuster aperture 64 . As noted above, the articulating body 40 is generally symmetric about a lateral plane, and thus the second adjuster 46 is similar to the first adjuster 44 , and the second adjuster 46 threads into an adjuster aperture disposed proximate to the second socket 66 of the articulating body 40 .
[0075] One skilled in the art will appreciate an accessory mount 34 made from any combination of connections and components may be used. For example, in one embodiment, the extension end 54 of an extension body 38 interconnects directly to a hub 2 or other object, thereby eliminating the need for a coupler 36 . An articulating body 40 interconnects to the extension body 38 in a ball-and-socket type interconnection, and a mount end is disposed at the other end of the articulating body 40 instead of a second socket 66 . An accessory may be interconnected to this mount end similar to the mount end 72 of the adapter 42 discussed elsewhere herein. In further embodiments, especially ones where articulation of the accessory is not needed, the accessory may attach directly into a coupler 36 or the hub 2 itself. For example, a scent dispenser does not need full articulation abilities and may attach to a coupler 36 or directly to a hub 2 .
[0076] In yet further embodiments, the coupler 36 may comprise more than one first end 50 for more than one extension body 38 . The extension body 38 may comprise more than one extension head 58 for more than one articulating body 40 . The articulating body 40 may comprise more than one second socket 66 for more than one adapter 42 . The adapter 42 may comprise more than one mount end 72 for more than one accessory. Etc.
[0077] Now referring to FIG. 18 , a tree screw 78 having a first section 80 , a second section 82 , and a handle 84 is provided. As mentioned above, not only may the coupler 36 —and more broadly the accessory mount 34 —attach to the hub 2 , the coupler 36 may also attach to other objects such as a tree screw 78 . It will be appreciated that the tree screw 78 replaces the coupler 36 in some embodiments of the accessory mount. In the embodiment depicted in FIG. 18 , the tree screw's 78 first section 80 has a threaded outer surface which tapers towards one end of the first section 80 . This configuration allows the first section 80 to penetrate and anchor in a tree, stump, or other material. A hex nut shape is disposed on another end of the first section 80 such that a user may “screw” the first section 80 into a tree with a wrench.
[0078] Once the first section 80 is anchored, a second section 82 may screw into a threaded recess within the first section 80 . A handle 84 is positioned at one end of the section 82 such that a user may stand on the handle 84 to scale a tree. A coupler 36 may also be selectively interconnected to the first section 80 such that an accessory mount 34 is selectively interconnected to a tree, stump, or other material. This configuration allows a user to secure a camera to a tree instead of carrying heavier equipment such as a tripod. One skilled in the art will appreciate that the end of any component of the accessory mount 34 such as the rod 48 of the coupler 36 or the interface end 54 of the extension body 38 may be similarly configured as the first section 80 of the tree screw 78 . Thus, the coupler 36 or the extension body 38 may directly screw into an axial thread 22 of the hub 2 , a tree, a stump, or other material, and the overall number of parts of the accessory mount 34 is reduced. One skilled in the art will further appreciate the variety of tree screw 78 configurations including single section designs and designs were the first section 80 is hingedly interconnected to the second section 82 .
[0079] The present invention has significant benefits across a broad spectrum of endeavors. It is the Applicant's intent that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed.
[0080] The phrases “at least one”, “one or more”, and “and/or”, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B, and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C,” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together.
[0081] Unless otherwise indicated, all numbers expressing quantities, dimensions, conditions, and so forth used in the specification, drawings, and claims are to be understood as being modified in all instances by the term “about.”
[0082] The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein.
[0083] The use of “including,” “comprising,” or “having,” and variations thereof, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof can be used interchangeably herein.
[0084] It shall be understood that the term “means” as used herein shall be given its broadest possible interpretation in accordance with 35 U.S.C. §112(f). Accordingly, a claim incorporating the term “means” shall cover all structures, materials, or acts set forth herein, and all of the equivalents thereof. Further, the structures, materials, or acts, and the equivalents thereof, shall include all those described in the summary of the invention, brief description of the drawings, detailed description, abstract, and claims themselves.
[0085] The foregoing description of the present invention has been presented for illustration and description purposes. However, the description is not intended to limit the invention to only the forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention.
[0086] Consequently, variations and modifications commensurate with the above teachings and skill and knowledge of the relevant art are within the scope of the present invention. The embodiments described herein above are further intended to explain best modes of practicing the invention and to enable others skilled in the art to utilize the invention in such a manner, or include other embodiments with various modifications as required by the particular application(s) or use(s) of the present invention. Thus, it is intended that the claims be construed to include alternative embodiments to the extent permitted by the prior art. | A tool-less hub is provided for hunting blinds and tent structures. Poles with particularly-shaped protrusions are insertable in and removable from the tool-less hub. The protrusions allow the pole to enter the tool-less hub at a particular angle, but once rotated to a different angle, the pole is secured with the hub. And thus, no tools are required to change out a broken pole from the hub. In addition, the tool-less hub may comprise a location for an accessory mount, which may comprise a plurality of bodies that articulate about each other. Accessories such as cameras, lights, game calls, scent dispensers, firearms, shelves, hooks, etc. may be interconnected to the accessory mount, and the articulating bodies may position the accessory in any number of locations and orientations. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/555,719 entitled “Product Tracing and Recall System,” filed Mar. 22, 2004. Priority is claimed thereto pursuant to 35 U.S.C. § 119(e).
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] None.
BACKGROUND OF THE INVENTION
[0003] The present invention relates generally to a system and method for tracing products. More specifically, the present invention encompasses a system and method for tracing agricultural commodities utilizing a tracing caplet containing identifying information for the commodity, a scanning device for reading the identifying information on the caplet, and a data retrieval and management system for tracing product movement.
[0004] To retain their comparative advantage in the global market and address domestic food safety and quality issues, commodity producers and handlers need to implement a system that can trace commodities back to their source. For example, if a bio-terror or major food safety event occurs, commodity trace back from any point in the marketing chain to the individual field or fields is an essential step in identifying the source of contamination. Additionally, trace back capability will expedite risk management strategies including product recall. Traceability may be defined to mean the ability to trace and follow a food, feed, food-producing substance intended to be or expected to be incorporated into a food or feed, through all stages of production and distribution.
[0005] Producers and processors have implemented identity-preserved traceability programs for a variety of reasons. For example, when genetically modified maize was approved for feed use, many dry millers implemented system wide identity-preserved traceability programs to insure that the modified maize did not find its way into consumer products. Currently, identity-preserved traceability programs rely on best management practices, inspection, and record keeping to achieve specified levels of purity and product identity. Thus, one company maintains dedicated commercial elevators to avoid commingling of products. Another company requires that producers maintain field maps that include identification of the crops grown in neighboring fields and confirm that only approved herbicides and insecticides are applied to their commodity. Clearly, the traceability programs currently in use are expensive to maintain, incompatible, difficult to implement, and of questionable reliability.
[0006] Accordingly, it is desirable to provide a system and method for tracing agricultural commodities that is inexpensive, scalable to a large marketing system, easy to use, and reliable.
BRIEF SUMMARY OF THE INVENTION
[0007] There is, therefore, provided in the practice of the invention a system and method for tracing a particular batch of an agricultural commodity from field to port. In accordance with one embodiment of the present invention, a system for tracing agricultural commodities comprises a plurality of tracing caplets. Each tracing caplet includes encoded information. The system also includes a scanning device capable of reading the encoded information on the caplets, and a data retrieval and management system operable to receive the caplet information and other data relating to the agricultural commodity. The data, which includes the present location of the commodity and the date and time, and the encoded information from the tracing caplet are stored by the data retrieval and management system, and a medium for that storage is provided. In one aspect of this embodiment, the caplet information is encoded using a bar code inscribed or printed on the caplet. In yet another aspect of this invention, the caplet is an radio frequency identification (“RFID”) tag.
[0008] In accordance with another embodiment of the present invention, there is provided a method for tracing agricultural commodities, the method comprising reading information encoded on a caplet contained in an agricultural commodity, and communicating the encoded information and addition data about the agricultural commodity to a data retrieval and management system.
[0009] In yet another embodiment of the invention, there is provided a method for tracing an agricultural commodity, the method comprising receiving data concerning an agricultural commodity, the data including the location of the agricultural commodity, and information from a caplet dispensed into the agricultural commodity, and storing the data and information in a database.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further features of the present invention will become apparent to those skilled in the art to which the present invention relates from reading the following description with reference to the accompanying drawings, in which:
[0011] FIG. 1 is a block diagram showing one embodiment of the system of the present invention;
[0012] FIG. 2 is a flow diagram that includes the steps from one embodiment of the method of the present invention and, in particular, when the caplets are inscribed with a bar code; and
[0013] FIG. 3 is a flow diagram that includes various steps from a second embodiment, that is when the caplet is an RFD) tag, of the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention includes a system and method for tracing agricultural commodities. The system is inexpensive and easy to implement and use. Additionally, the system is scalable to large marketing systems. The system and method of the present invention will be described using wheat as the commodity. It should be understood and appreciated that the system and method are equally applicable to other commodities.
[0015] Turning now to the figures, FIG. 1 shows one embodiment of the system of the present invention in a large marketing/distribution system. Regarding the marketing/distribution system, initially wheat is grown in a farm field 10 by a wheat producer. The wheat is harvested through the use of a combine 20 and unloaded at an elevator 30 in bulk. Alternatively, the wheat is unloaded from the combine 20 to farm storage 40 and is transported to the elevator 30 at a later date. From the elevator 30 , the wheat is transported to a terminal/processor 50 usually by truck or rail. Next, as desired, the wheat is transported in bulk to an export terminal 60 and, thereafter, it is transported to a port 70 . Typically, the wheat is transported to the export terminal 60 by rail or barge and to the port 70 by a vessel.
[0016] The present invention includes tracing caplets 80 containing information used to identify the wheat from an individual field or location. The tracing caplets 80 are distributed into the bulk grain and, in one embodiment, possess physical and chemical properties similar to wheat. Thus, in one embodiment, the caplets 80 will be made from a wheat material such as whole wheat ground using a Jacobson hammer mill equipped with a 2 mm screen opening, hard red winter wheat straight grade flour, farina (purified middlings of hard red winter wheat flour), or semolina (large particles of durum wheat). All products used in the formation of the caplets 80 are food-grade materials that will not pose potential hazards to people. Once in the wheat, these caplets 80 do not require any additional precautions other than the safety measures already in use when handling grain. Additionally, it will not be necessary to remove any caplets 80 remaining in the wheat prior to processing because the caplets 80 do not pose any food safety threat and will not affect the functional properties of the grain.
[0017] The caplets 80 according to this embodiment are formed using a die and applying thermal processing and pressure to have a density similar to a wheat kernel so that they will be easily incorporated with bulk wheat grain. The caplets 80 have a different shape and length when compared to a typical wheat grain which allows the caplets 80 to be removed with a standard grain cleaner. In one embodiment, the caplets 80 are pellets. In one embodiment, the caplets 80 are pellets having the following physical properties: a length of 6 mm; a diameter of 4 mm; a weight of 87 mg; and a density of 1.15 g/cm 3 . One device suitable for manufacturing pellets is the Model 1000 series “Master HD” pellet mill by the California Pellet Mill Company of Crawfordsville, Ind.
[0018] After the caplets 80 are formed, they are sprayed in one embodiment with a food grade protective multi-dextrin coating. Many commercially available multi-dextrin coating products, such as products provided by the Grain Processing Corporation of Muscatine, Iowa, would provide a sufficient coating. Several application methods may be used including aqueous film coating using perforated pan technology, pan coating, and dipping.
[0019] In another embodiment, the caplets 80 are made from carbohydrate or non-protein, non-allergenic ingredients. These caplets 80 are “universal” caplets, that is, the caplets are usable in any type of commodity. In one embodiment, these caplets are made from corn syrup and sugar.
[0020] The caplets 80 will be encoded with information in a manner so that the information is readable by a scanning device 90 . In one embodiment, the caplets 80 are encoded with a bar code provided on the caplet, and the scanning device 90 is a handheld bar code reader. One suitable bar code reader is an IT4088SR bar code reader manufactured by Hand Held Products Corporation, Skaneateles Falls, N.Y. Though factual data regarding the product is encoded and provided on the caplets in some embodiments, the information serves as a pointer to data regarding the product with which the caplet is placed. Thus, in the present embodiment, the information contains only a caplet identifier.
[0021] In another embodiment, the caplets are a Radio Frequency Identification (RFID) tag. In one embodiment an RFID tag is manufactured with material that is not harmful to humans or animals if ingested. However, to decrease the impurities, the RFID tag is removed in one embodiment prior to processing. In one embodiment, the RFID tags also are manufactured within the same size limits mentioned above so that these caplets also can be easily separated from the remaining grain. When the caplet information is encoded on the RFID tag, the scanning device 90 is an RFID reader.
[0022] Wheat producers will receive their allotted share of tracing caplets 80 prior to harvest. The producer is responsible for coordinating the caplets 80 to the designated field, or providing the caplets 80 to the harvesters who will be responsible for the wheat collection. There are several points at which delivery of the caplets 80 is possible. The caplets 80 can be introduced between the combine's final cleaning process and the grain bin. The clean grain lower cross auger, vertical elevator, and bin filling auger are also possible locations for delivery of the caplets 80 .
[0023] Continuing with FIG. 1 , in one embodiment, the tracing caplets 80 are distributed into the grain by means of a dispensing mechanism 100 located in the unloading auger of the combine 20 as the grain is transferred from the combine 20 to a truck or grain cart. Typically, grain flow rate is relatively constant during the unloading process. Thus, when the caplets 80 are dispensed at a constant rate, a uniform distribution of caplets in the grain is achieved.
[0024] The dispensing mechanism 100 in this embodiment includes a commercially available seed dispenser with fluted-feed grain drill cups and an electrically powered metering mechanism. The dispenser 100 is attached to the combine 20 by welding and/or clamping the dispenser 100 to the metal frame of the combine 20 . One possible position for the dispenser 100 is just downstream of the upper gearbox that connects the vertical unloading auger to the horizontal auger. Placement of the dispensing mechanism 100 in this position typically requires only the removal of an inspection plate. No permanent modifications are required. In one embodiment, the caplets 80 are dispensed by the dispensing mechanism 100 into a plastic pipe which delivers the caplets into the grain stream close to the unloading auger.
[0025] The dispenser 100 should be sized so that it need only be filled once daily in order to avoid interruption of the harvest. Thus, in one embodiment, the dispenser 100 has a 30 liter capacity which would contain about 23.1 kg of the caplets 80 described above. For a discharge rate of 0.015% of caplets on a mass basis, this number of caplets would mark approximately 154,000 kg of wheat which falls roughly in the range of a typical combine's daily capacity.
[0026] The dispenser 100 is powered by a 12 volt DC motor that is wired to operate whenever the unloading auger is engaged. Because the current required for the motor is significant in comparison to the current needed to operate the hydraulic valves of the auger, it is not possible generally to pass the dispenser current through the switch that activates the unloading auger. Therefore, an appropriate relay configured to pass current when the unloading auger is engaged is utilized.
[0027] In one embodiment, the dispenser 100 is equipped with a cleanout door (not shown) to allow the discharge of unused caplets which will facilitate rapid changing of caplets 80 between fields or farms. The generally benign nature of the caplets 80 should allow excess caplets to be discharged in the field for decomposition.
[0028] For caplets 80 that are about the size and density as the grain, such as the caplets described above, utilizing the dispensing mechanism 100 describe above, it has been determined that one effective dispensing rate for caplets similar to wheat is 568 caplets per second assuming an unloading capacity of 78 liters per second. This dispensing rate yields a relatively uniform concentration of caplets 80 that is not too large so that caplets are wasted or too small so that excessive precautions are necessary to insure a caplet is found during the separation process.
[0029] Returning to FIG. 1 , initially the wheat producer will report a code or identifier from the caplets 80 , the field harvested or to be harvested, and the date the caplets 80 were dispensed to the data retrieval and management system 110 . In one embodiment the producer will communicate this information by way of a communications network 120 such as the Internet. Alternatively, the producer establishes direct communication with the data retrieval and management system 110 , for example, through a telephone line.
[0030] Thereafter, each grain receiving facility, such as elevator 30 , terminal/processor 50 , export terminal 60 , and port 70 , will collect caplet information. In one embodiment, a representative sample of the wheat is removed, and the caplets 80 are separated by use of a grain cleaner. In one embodiment, the caplets 80 are recovered using a 4.76 mm ( 12/64″) sieve. The caplets 80 recovered will then be scanned using scanning device 90 and, thereafter, the coded information and possibly additional data will be submitted to the data retrieval and management system 110 . In one embodiment, the coded information and data are submitted to the data retrieval and management system 110 by way of a communications network 120 . In various embodiments, the network 120 is the Internet or the telephone system. In an alternate embodiment, the scanning takes place at each receiving facility as the grain or other product flows into the facility. In another embodiment, the caplets are automatically scanned without removal of the caplets from the product. This is accomplished by continuously monitoring for either radio frequency signals or bar code recognition. If the automatic scanning does not read a caplet, then a sample can be taken as described above.
[0031] The data retrieval and management system 110 stores data from wheat samples and the identification points along the delivery route beginning at the farm field 10 and ending at that point where the wheat exits the marketing system. The system 110 additionally includes a user interface to process queries and provides a reporting capability. In one embodiment, the bar code is an identifying tag which is assigned to a specific producer. This bar code or RFID is used to correlate specific grain varieties, growing treatments, and field locations. Other data can also be tracked such as weather and yields.
[0032] In one embodiment, the data retrieval and management system 110 includes a database created in SQL Server 2000 that resides on a server located at a central location. The database includes three tables: one table entitled fields; a second table entitled samples; and a third table entitled locations. The fields table includes attributes for the caplet code, the farm identification, a tract number, a field number, the latitude and the longitude of the field, the country in which the field is located, the grain type, and the date the caplets are dispensed into the grain. The samples table includes attributes for the caplet code, the location where the sample is taken, the date and time the sample is taken, the carrier information, and the country where the sample is taken. The locations table includes attributes for the name, the latitude and longitude, and the address of the location, and the type of the location.
[0033] Data entry for the system 110 occurs through a user interface such as a graphical user interface. In one embodiment, the user interface is defined and/or delineated using Visual Basic. In another embodiment, the user interface is defined and/or delineated using Visual C++. Other programming languages will also suffice. In an embodiment, the user interface is downloaded to a computer or other processing device at the site where the information is entered.
[0034] In addition to accepting data input from the producer and/or the scanning devices 90 , the user interface provides various queries that allow information about samples to be viewed generally or sorted by location, caplet code, or date. In one embodiment, the queries are made using hypertext preprocessor (“PHP”) scripts and output as HTML or PDF documents that are printed on a printing device. In one embodiment, the information is provided on a map, such as the map of a state divided into counties, created as a portable network graphics (“PNG”) image with a PHP script.
[0035] Turning now to FIG. 2 , this figure shows a flow diagram that includes various steps of the method of one embodiment of the present invention, and in particular, an embodiment utilizing a bar code inscribed on each caplet. Beginning in box 130 , a manufacturer produces the caplets 80 . As stated above, the caplets 80 are formed using a die and applying thermal processing and pressure to have a density similar to a wheat kernel so that they will be easily incorporated with bulk wheat grain. Next, in box 140 , the caplet information is encoded. In this embodiment, this encoding takes the form of inscribing a bar code on each caplet.
[0036] Continuing with FIG. 2 , in box 160 the producer receives the encoded caplets 80 . Next, in box 170 , the producer will coordinate the caplets 80 that will be dispersed into and thereby associated with the product from a particular field 10 and the date that dispersion will occur and submit this data and the caplet information to the data retrieval and management system 110 . Once the information is submitted, the method continues in box 180 where the producer or his or her surrogate will dispense the caplets 80 into the appropriate product or, alternatively, the method continues in box 230 as described below.
[0037] In box 190 , operators at various points in the marketing/distribution process take a sample of the product. In one embodiment, the sample size is 1 liter of product. Next, in box 200 , an operator will separate the caplets from the grain, for example by running the sample through a grain cleaner. Following this separation, in box 200 , the caplet information is read by a bar code reader, and, in box 220 , this information and possibly additional data is submitted to the data retrieval and management system 110 . In an alternate embodiment, the product is continuously scanned, and samples are taken only if the automated scan fails to read caplet information.
[0038] In box 230 , which follows either box 170 or box 220 , the data and caplet information is received by the data retrieval and management system 110 . Thereafter, in box 240 , the data and caplet information is stored, for example in the tables mentioned above. In box 250 , the data retrieval and management system 110 responds to any queries posed by either the operator or the producer. Finally, in box 260 , the data retrieval and management system prepares and presents if appropriate any reports requested by either the operator or the producer.
[0039] Turning now to FIG. 3 , this figure shows a flow diagram that includes various steps of the method of one embodiment of the present invention, and in particular, an embodiment in which the caplet is an RFID tag. As in FIG. 2 , this embodiment begins with boxes 130 , 140 , and 150 . Boxes 130 and 150 are the same as in FIG. 2 . Box 140 , however, is different in that the encoding is accomplished by programming the RFID tag.
[0040] The method of this embodiment continues with boxes 160 , 170 and 180 . These boxes are also the same as in FIG. 2 except that box 270 follows box 180 instead of box 190 as in FIG. 2 .
[0041] In box 270 , the caplet information is read utilizing an RFID scanning device. Unlike in FIG. 2 , there is no need to take a sample and separate the caplets in order to read the information. Instead, the RFID tag transmits a radio frequency wave that the scanning device reads from a distance.
[0042] After it is read, the caplet information and possibly additional data is submitted to the data retrieval and management system 110 in box 280 . Thereafter, the method continues in box 230 . Alternatively, if the grain is at the final point in the marketing process and it is deemed appropriate and desirable, then the method continues in box 290 where the caplets are separated from the grain. Box 230 follows both box 280 and box 290 and is the same as in FIG. 2 . Likewise, boxes 240 , 250 , and 260 are the same as in FIG. 2 .
[0043] Having described the invention, it should be apparent that the invention is both inexpensive and easy to implement and use especially when compared to current identity-preserved tracing programs. Additionally, the system is scalable to large marketing systems and could be used across the entire market for a given commodity. Although the above system and method are described using wheat, as stated above, it will be appreciated that system and method are equally applicable to other commodities. Additionally, from the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims. | The present invention encompasses a system and method for tracing a particular load or series of a bulk agricultural commodity throughout the marketing process. The system includes a plurality of tracing caplets ( 80 ), each tracing caplet ( 80 ) including encoded information, a scanning device ( 90 ) capable of reading the encoded information, and a data retrieval and management system ( 110 ) operable to receive and store data, including the encoded information from a tracing caplet ( 80 ), concerning the agricultural commodity. One method for tracing agricultural commodities comprises reading information ( 210 ) encoded on a caplet contained in an agricultural commodity, and communicating ( 220 ) the information and additional data about the agricultural commodity to a data retrieval and management system ( 110 ). In another method of the present invention, data concerning an agricultural commodity is received, the data including the location of the agricultural commodity and information from a caplet dispensed into the agricultural commodity, and the data and information are stored in a database. | 6 |
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